Science.gov

Sample records for bee populations forest

  1. Modeling Honey Bee Populations.

    PubMed

    Torres, David J; Ricoy, Ulises M; Roybal, Shanae

    2015-01-01

    Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population.

  2. Modeling Honey Bee Populations

    PubMed Central

    Torres, David J.; Ricoy, Ulises M.; Roybal, Shanae

    2015-01-01

    Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population. PMID:26148010

  3. Modeling Honey Bee Populations.

    PubMed

    Torres, David J; Ricoy, Ulises M; Roybal, Shanae

    2015-01-01

    Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population. PMID:26148010

  4. Effects of suburbanization on forest bee communities.

    PubMed

    Carper, Adrian L; Adler, Lynn S; Warren, Paige S; Irwin, Rebecca E

    2014-04-01

    Urbanization is a dominant form of land-use change driving species distributions, abundances, and diversity. Previous research has documented the negative impacts of urbanization on the abundance and diversity of many groups of organisms. However, some organisms, such as bees, may benefit from moderate levels of development, depending on how development alters the availability of foraging and nesting resources. To determine how one type of low-intensity human development, suburbanization, affects bee abundance and diversity and the mechanisms involved, we surveyed bees across suburban and natural forests in the Raleigh-Durham area of North Carolina. We sampled for bees using a combination of bee bowls and hand-netting from March through July of 2008 and 2009. We found higher bee abundance in suburban than natural forests, and although observed species richness was greater in suburban than natural forests, there were no significant differences in rarefied richness or evenness estimates in either year. In addition, the effects of suburbanization were similar across bee species of varying ecological and life-history characteristics. At the local scale, bee abundance and species richness were both positively related to the abundance and richness of flowering species within forests, while the proportion of surrounding developed open areas, such as yards and roadsides, was a strong positive predictor of both bee abundance and richness at the landscape scale. These results suggest that open habitats and the availability of floral resources in suburban sites can support abundant and diverse bee communities and underscore the potential for native bee conservation in urban habitats.

  5. Among-Population Variation in Microbial Community Structure in the Floral Nectar of the Bee-Pollinated Forest Herb Pulmonaria officinalis L

    PubMed Central

    Jacquemyn, Hans; Lenaerts, Marijke; Brys, Rein; Willems, Kris; Honnay, Olivier; Lievens, Bart

    2013-01-01

    Background Microbial communities in floral nectar have been shown to be characterized by low levels of species diversity, yet little is known about among-plant population variation in microbial community composition. Methodology/Principal Findings We investigated the microbial community structure (yeasts and bacteria) in floral nectar of ten fragmented populations of the bee-pollinated forest herb Pulmonaria officinalis. We also explored possible relationships between plant population size and microbial diversity in nectar, and related microbial community composition to the distance separating plant populations. Culturable bacteria and yeasts occurring in the floral nectar of a total of 100 plant individuals were isolated and identified by partially sequencing the 16S rRNA gene and D1/D2 domains of the 26S rRNA gene, respectively. A total of 9 and 11 yeast and 28 and 39 bacterial OTUs was found, taking into account a 3% (OTU0.03) and 1% sequence dissimilarity cut-off (OTU0.01). OTU richness at the plant population level (i.e. the number of OTUs per population) was low for yeasts (mean: 1.7, range: 0–4 OTUs0.01/0.03 per population), whereas on average 6.9 (range: 2–13) OTUs0.03 and 7.9 (range 2–16) OTUs0.01 per population were found for bacteria. Both for yeasts and bacteria, OTU richness was not significantly related to plant population size. Similarity in community composition among populations was low (average Jaccard index: 0.14), and did not decline with increasing distance between populations. Conclusions/Significance We found low similarity in microbial community structure among populations, suggesting that the assembly of nectar microbiota is to a large extent context-dependent. Although the precise factors that affect variation in microbial community structure in floral nectar require further study, our results indicate that both local and regional processes may contribute to among-population variation in microbial community structure in nectar. PMID

  6. Forested landscapes promote richness and abundance of native bees (Hymenoptera: Apoidea: Anthophila) in Wisconsin apple orchards.

    PubMed

    Watson, J C; Wolf, A T; Ascher, J S

    2011-06-01

    Wild bees provide vital pollination services for many native and agricultural plant species, yet the landscape conditions needed to support wild bee populations are not well understood or appreciated. We assessed the influence of landscape composition on bee abundance and species richness in apple (Malus spp.) orchards of northeastern Wisconsin during the spring flowering period. A diverse community of bee species occurs in these apple orchards, dominated by wild bees in the families Andrenidae and Halictidae and the honey bee, Apis mellifera L. Proportion of forest area in the surrounding landscape was a significant positive predictor of wild bee abundance in orchards, with strongest effects at a GIS (Geographic Information Systems) buffer distance of 1,000 m or greater. Forest area also was positively associated with species richness, showing strongest effects at a buffer distance of 2,000 m. Nonagricultural developed land (homes, lawns, etcetera) was significantly negatively associated with species richness at buffer distances >750 m and wild bee abundance in bowl traps at all distances. Other landscape variables statistically associated with species richness or abundance of wild bees included proportion area of pasture (positive) and proportion area of roads (negative). Forest area was not associated with honey bee abundance at any buffer distance. These results provide clear evidence that the landscape surrounding apple orchards, especially the proportion of forest area, affects richness and abundance of wild bees during the spring flowering period and should be a part of sustainable land management strategies in agro-ecosystems of northeastern Wisconsin and other apple growing regions. PMID:22251640

  7. Forested landscapes promote richness and abundance of native bees (Hymenoptera: Apoidea: Anthophila) in Wisconsin apple orchards.

    PubMed

    Watson, J C; Wolf, A T; Ascher, J S

    2011-06-01

    Wild bees provide vital pollination services for many native and agricultural plant species, yet the landscape conditions needed to support wild bee populations are not well understood or appreciated. We assessed the influence of landscape composition on bee abundance and species richness in apple (Malus spp.) orchards of northeastern Wisconsin during the spring flowering period. A diverse community of bee species occurs in these apple orchards, dominated by wild bees in the families Andrenidae and Halictidae and the honey bee, Apis mellifera L. Proportion of forest area in the surrounding landscape was a significant positive predictor of wild bee abundance in orchards, with strongest effects at a GIS (Geographic Information Systems) buffer distance of 1,000 m or greater. Forest area also was positively associated with species richness, showing strongest effects at a buffer distance of 2,000 m. Nonagricultural developed land (homes, lawns, etcetera) was significantly negatively associated with species richness at buffer distances >750 m and wild bee abundance in bowl traps at all distances. Other landscape variables statistically associated with species richness or abundance of wild bees included proportion area of pasture (positive) and proportion area of roads (negative). Forest area was not associated with honey bee abundance at any buffer distance. These results provide clear evidence that the landscape surrounding apple orchards, especially the proportion of forest area, affects richness and abundance of wild bees during the spring flowering period and should be a part of sustainable land management strategies in agro-ecosystems of northeastern Wisconsin and other apple growing regions.

  8. Floral and nesting resources, habitat structure, and fire influence bee distribution across an open-forest gradient.

    PubMed

    Grundel, Ralph; Jean, Robert P; Frohnapple, Krystalynn J; Glowacki, Gary A; Scott, Peter E; Pavlovic, Noel B

    2010-09-01

    Given bees' central effect on vegetation communities, it is important to understand how and why bee distributions vary across ecological gradients. We examined how plant community composition, plant diversity, nesting suitability, canopy cover, land use, and fire history affected bee distribution across an open-forest gradient in northwest Indiana, USA, a gradient similar to the historic Midwest United States landscape mosaic. When considered with the other predictors, plant community composition was not a significant predictor of bee community composition. Bee abundance was negatively related to canopy cover and positively to recent fire frequency, bee richness was positively related to plant richness and abundance of potential nesting resources, and bee community composition was significantly related to plant richness, soil characteristics potentially related to nesting suitability, and canopy cover. Thus, bee abundance was predicted by a different set of environmental characteristics than was bee species richness, and bee community composition was predicted, in large part, by a combination of the significant predictors of bee abundance and richness. Differences in bee community composition along the woody vegetation gradient were correlated with relative abundance of oligolectic, or diet specialist, bees. Because oligoleges were rarer than diet generalists and were associated with open habitats, their populations may be especially affected by degradation of open habitats. More habitat-specialist bees were documented for open and forest/scrub habitats than for savanna/woodland habitats, consistent with bees responding to habitats of intermediate woody vegetation density, such as savannas, as ecotones rather than as distinct habitat types. Similarity of bee community composition, similarity of bee abundance, and similarity of bee richness between sites were not significantly related to proximity of sites to each other. Nestedness analysis indicated that species

  9. Floral and nesting resources, habitat structure, and fire influence bee distribution across an open-forest gradient

    USGS Publications Warehouse

    Grundel, R.; Jean, R.P.; Frohnapple, K.J.; Glowacki, G.A.; Scott, P.E.; Pavlovic, N.B.

    2010-01-01

    Given bees' central effect on vegetation communities, it is important to understand how and why bee distributions vary across ecological gradients. We examined how plant community composition, plant diversity, nesting suitability, canopy cover, land use, and fire history affected bee distribution across an open-forest gradient in northwest Indiana, USA, a gradient similar to the historic Midwest United States landscape mosaic. When considered with the other predictors, plant community composition was not a significant predictor of bee community composition. Bee abundance was negatively related to canopy cover and positively to recent fire frequency, bee richness was positively related to plant richness and abundance of potential nesting resources, and bee community composition was significantly related to plant richness, soil characteristics potentially related to nesting suitability, and canopy cover. Thus, bee abundance was predicted by a different set of environmental characteristics than was bee species richness, and bee community composition was predicted, in large part, by a combination of the significant predictors of bee abundance and richness. Differences in bee community composition along the woody vegetation gradient were correlated with relative abundance of oligolectic, or diet specialist, bees. Because oligoleges were rarer than diet generalists and were associated with open habitats, their populations may be especially affected by degradation of open habitats. More habitat-specialist bees were documented for open and forest/scrub habitats than for savanna/woodland habitats, consistent with bees responding to habitats of intermediate woody vegetation density, such as savannas, as ecotones rather than as distinct habitat types. Similarity of bee community composition, similarity of bee abundance, and similarity of bee richness between sites were not significantly related to proximity of sites to each other. Nestedness analysis indicated that species

  10. Changes in Orchid Bee Communities Across Forest-Agroecosystem Boundaries in Brazilian Atlantic Forest Landscapes.

    PubMed

    De Aguiar, Willian Moura; Sofia, Silvia H; Melo, Gabriel A R; Gaglianone, Maria Cristina

    2015-12-01

    Deforestation has dramatically reduced the extent of Atlantic Forest cover in Brazil. Orchid bees are key pollinators in neotropical forest, and many species are sensitive to anthropogenic interference. In this sense understanding the matrix permeability for these bees is important for maintaining genetic diversity and pollination services. Our main objective was to assess whether the composition, abundance, and diversity of orchid bees in matrices differed from those in Atlantic forest. To do this we sampled orchid bees at 4-mo intervals from 2007 to 2009 in remnants of Atlantic Forest, and in the surrounding pasture and eucalyptus matrices. The abundance, richness, and diversity of orchid bees diminished significantly from the forest fragment toward the matrix points in the eucalyptus and pasture. Some common or intermediate species in the forest areas, such as Eulaema cingulata (F.) and Euglossa fimbriata Moure, respectively, become rare species in the matrices. Our results show that the orchid bee community is affected by the matrices surrounding the forest fragments. They also suggest that connections between forest fragments need to be improved using friendly matrices that can provide more favorable conditions for bees and increase their dispersal between fragments.

  11. Eufriesea violacea (Blanchard) (Hymenoptera: Apidae): an orchid bee apparently sensitive to size reduction in forest patches.

    PubMed

    Giangarelli, Douglas C; Freiria, Gabriele A; Colatreli, Olavo P; Suzuki, Karen M; Sofia, Silvia H

    2009-01-01

    Eufriesea violacea (Blanchard) is a very seasonal euglossine species, more frequently found in the southern and southeastern regions of Brazil. A number of studies have revealed large variations in the abundance of males of this species present in Atlantic Forest remnants throughout both regions. In this paper, we report variations in the abundance of E. violacea males sampled in several forest patches of different sizes (ranging from 10 to 580 ha), and we propose that this species is possibly sensitive to the reduction in size of forest remnants. Surveys were carried out in nine forest remnants of Atlantic rainforest located in northern Paraná State, southern Brazil. Male euglossine bees were collected with an entomological net when visiting scent-baits, between 10:00 am and 1:00 pm, from October to December of 2001 and 2006. A total of 360 E. violacea males were captured in the nine forest fragments studied. The number of bees attracted to scent baits in each forest patch varied from zero to 261. A very high association (r = 0.993) was detected between the forest patch size and the visitation rate of E. violacea males at different sites, with the highest mean number of males visiting baits/sampling (43.5) being observed for bees from the largest forest remnant. Although alternative hypothesis should not be discharged for the decline in the abundance or absence of E. violacea in small forest patches, our results indicate that populations of this euglossine species need larger forest areas for existing. PMID:19943008

  12. A quantitative model of honey bee colony population dynamics.

    PubMed

    Khoury, David S; Myerscough, Mary R; Barron, Andrew B

    2011-01-01

    Since 2006 the rate of honey bee colony failure has increased significantly. As an aid to testing hypotheses for the causes of colony failure we have developed a compartment model of honey bee colony population dynamics to explore the impact of different death rates of forager bees on colony growth and development. The model predicts a critical threshold forager death rate beneath which colonies regulate a stable population size. If death rates are sustained higher than this threshold rapid population decline is predicted and colony failure is inevitable. The model also predicts that high forager death rates draw hive bees into the foraging population at much younger ages than normal, which acts to accelerate colony failure. The model suggests that colony failure can be understood in terms of observed principles of honey bee population dynamics, and provides a theoretical framework for experimental investigation of the problem. PMID:21533156

  13. A Quantitative Model of Honey Bee Colony Population Dynamics

    PubMed Central

    Khoury, David S.; Myerscough, Mary R.; Barron, Andrew B.

    2011-01-01

    Since 2006 the rate of honey bee colony failure has increased significantly. As an aid to testing hypotheses for the causes of colony failure we have developed a compartment model of honey bee colony population dynamics to explore the impact of different death rates of forager bees on colony growth and development. The model predicts a critical threshold forager death rate beneath which colonies regulate a stable population size. If death rates are sustained higher than this threshold rapid population decline is predicted and colony failure is inevitable. The model also predicts that high forager death rates draw hive bees into the foraging population at much younger ages than normal, which acts to accelerate colony failure. The model suggests that colony failure can be understood in terms of observed principles of honey bee population dynamics, and provides a theoretical framework for experimental investigation of the problem. PMID:21533156

  14. The impact of forest exploitation on Amazonian stingless bees (Apidae, Meliponini).

    PubMed

    Venturieri, G C

    2009-01-01

    The protocols available to sustainably exploit natural forest resources are known as "sustainable forest management". This type of management generally does not take into account the effect of timber exploitation on pollinators. Stingless bees, which include many species that play an important role as pollinators and are quite diverse in the Amazon, preferentially make their perennial nests in the base of hollow trees. Normally, during sustainable exploitation of trees, hollow trees are not cut down; however, predatory exploitation of such trees could severely affect natural populations of this pollinator group. PMID:19554767

  15. Modelling food and population dynamics in honey bee colonies.

    PubMed

    Khoury, David S; Barron, Andrew B; Myerscough, Mary R

    2013-01-01

    Honey bees (Apis mellifera) are increasingly in demand as pollinators for various key agricultural food crops, but globally honey bee populations are in decline, and honey bee colony failure rates have increased. This scenario highlights a need to understand the conditions in which colonies flourish and in which colonies fail. To aid this investigation we present a compartment model of bee population dynamics to explore how food availability and bee death rates interact to determine colony growth and development. Our model uses simple differential equations to represent the transitions of eggs laid by the queen to brood, then hive bees and finally forager bees, and the process of social inhibition that regulates the rate at which hive bees begin to forage. We assume that food availability can influence both the number of brood successfully reared to adulthood and the rate at which bees transition from hive duties to foraging. The model predicts complex interactions between food availability and forager death rates in shaping colony fate. Low death rates and high food availability results in stable bee populations at equilibrium (with population size strongly determined by forager death rate) but consistently increasing food reserves. At higher death rates food stores in a colony settle at a finite equilibrium reflecting the balance of food collection and food use. When forager death rates exceed a critical threshold the colony fails but residual food remains. Our model presents a simple mathematical framework for exploring the interactions of food and forager mortality on colony fate, and provides the mathematical basis for more involved simulation models of hive performance. PMID:23667418

  16. Modelling Food and Population Dynamics in Honey Bee Colonies

    PubMed Central

    Khoury, David S.; Barron, Andrew B.; Myerscough, Mary R.

    2013-01-01

    Honey bees (Apis mellifera) are increasingly in demand as pollinators for various key agricultural food crops, but globally honey bee populations are in decline, and honey bee colony failure rates have increased. This scenario highlights a need to understand the conditions in which colonies flourish and in which colonies fail. To aid this investigation we present a compartment model of bee population dynamics to explore how food availability and bee death rates interact to determine colony growth and development. Our model uses simple differential equations to represent the transitions of eggs laid by the queen to brood, then hive bees and finally forager bees, and the process of social inhibition that regulates the rate at which hive bees begin to forage. We assume that food availability can influence both the number of brood successfully reared to adulthood and the rate at which bees transition from hive duties to foraging. The model predicts complex interactions between food availability and forager death rates in shaping colony fate. Low death rates and high food availability results in stable bee populations at equilibrium (with population size strongly determined by forager death rate) but consistently increasing food reserves. At higher death rates food stores in a colony settle at a finite equilibrium reflecting the balance of food collection and food use. When forager death rates exceed a critical threshold the colony fails but residual food remains. Our model presents a simple mathematical framework for exploring the interactions of food and forager mortality on colony fate, and provides the mathematical basis for more involved simulation models of hive performance. PMID:23667418

  17. Descriptive attributes used in the characterization of stingless bees (Apidae: Meliponini) in rural populations of the Atlantic forest (Misiones-Argentina)

    PubMed Central

    2012-01-01

    Abstract Background Human beings employ a combination of morphological, sensorial, utilitarian, cultural and ecological characters when they identify and classify organisms. Ethnotaxonomy has provided a store of information about the characters cultures employ when they identify and classify a vast diversity of taxonomic groups. Nevertheless, some more research is needed to provide a comparison of the characters employed in the description of taxons, and an analysis of the extent to which those descriptors are represented. Stingless bees constitute a diverse group of social insects that have been widely studied from an ethnobiological perspective due to their utilitarian and cultural importance. The objective of this study is to identify the elements local people consider when characterizing stingless bees, and how important these elements are in the study of local classifications. Methods The methodology used involves semi-structured interviews and trips with the informants to rural areas. Locally known ethnospecies are characterized, descriptive traits and salient criteria used in those characterizations are identified, and the frequency of reference of descriptive traits and salient criteria are estimated. Besides, the descriptive traits used for each ethnospecies are compared, and the contribution of the characterizations as a heuristic strategy in the study of folk classification systems is analyzed. Results The use of 19 biological descriptors (grouped according to 4 salient criteria) and of comparisons among ethnospecies was found. Results suggest the existence of group and specific descriptors. Researchers identified which ethnospecies are considered similar, how less important traits contribute to descriptions, the relation between specific descriptors and ethnospecies, the presence of cognitive prototypes, and the most relevant salient properties from the emic perspective. Conclusions The estimated importance of attributes descriptors allowed us to

  18. Descriptive attributes used in the characterization of stingless bees (Apidae: Meliponini) in rural populations of the Atlantic forest (Misiones-Argentina)

    PubMed Central

    2012-01-01

    Abstract Background Human beings employ a combination of morphological, sensorial, utilitarian, cultural and ecological characters when they identify and classify organisms. Ethnotaxonomy has provided a store of information about the characters cultures employ when they identify and classify a vast diversity of taxonomic groups. Nevertheless, some more research is needed to provide a comparison of the characters employed in the description of taxons, and an analysis of the extent to which those descriptors are represented. Stingless bees constitute a diverse group of social insects that have been widely studied from an ethnobiological perspective due to their utilitarian and cultural importance. The objective of this study is to identify the elements local people consider when characterizing stingless bees, and how important these elements are in the study of local classifications. Methods The methodology used involves semi-structured interviews and trips with the informants to rural areas. Locally known ethnospecies are characterized, descriptive traits and salient criteria used in those characterizations are identified, and the frequency of reference of descriptive traits and salient criteria are estimated. Besides, the descriptive traits used for each ethnospecies are compared, and the contribution of the characterizations as a heuristic strategy in the study of folk classification systems is analyzed. Results The use of 19 biological descriptors (grouped according to 4 salient criteria) and of comparisons among ethnospecies was found. Results suggest the existence of group and specific descriptors. Researchers identified which ethnospecies are considered similar, how less important traits contribute to descriptions, the relation between specific descriptors and ethnospecies, the presence of cognitive prototypes, and the most relevant salient properties from the emic perspective. Conclusions The estimated importance of attributes descriptors allowed us to

  19. Succession influences wild bees in a temperate forest landscape: the value of early successional stages in naturally regenerated and planted forests.

    PubMed

    Taki, Hisatomo; Okochi, Isamu; Okabe, Kimiko; Inoue, Takenari; Goto, Hideaki; Matsumura, Takeshi; Makino, Shun'ichi

    2013-01-01

    In many temperate terrestrial forest ecosystems, both natural human disturbances drive the reestablishment of forests. Succession in plant communities, in addition to reforestation following the creation of open sites through harvesting or natural disturbances, can affect forest faunal assemblages. Wild bees perform an important ecosystem function in human-altered and natural or seminatural ecosystems, as they are essential pollinators for both crops and wild flowering plants. To maintain high abundance and species richness for pollination services, it is important to conserve and create seminatural and natural land cover with optimal successional stages for wild bees. We examined the effects of forest succession on wild bees. In particular, we evaluated the importance of early successional stages for bees, which has been suspected but not previously demonstrated. A range of successional stages, between 1 and 178 years old, were examined in naturally regenerated and planted forests. In total 4465 wild bee individuals, representing 113 species, were captured. Results for total bees, solitary bees, and cleptoparasitic bees in both naturally regenerated and planted conifer forests indicated a higher abundance and species richness in the early successional stages. However, higher abundance and species richness of social bees in naturally regenerated forest were observed as the successional stages progressed, whereas the abundance of social bees in conifer planted forest showed a concave-shaped relationship when plotted. The results suggest that early successional stages of both naturally regenerated and conifer planted forest maintain a high abundance and species richness of solitary bees and their cleptoparasitic bees, although social bees respond differently in the early successional stages. This may imply that, in some cases, active forest stand management policies, such as the clear-cutting of planted forests for timber production, would create early successional

  20. Distance from forest edge affects bee pollinators in oilseed rape fields

    PubMed Central

    Bailey, Samantha; Requier, Fabrice; Nusillard, Benoît; Roberts, Stuart P M; Potts, Simon G; Bouget, Christophe

    2014-01-01

    Wild pollinators have been shown to enhance the pollination of Brassica napus (oilseed rape) and thus increase its market value. Several studies have previously shown that pollination services are greater in crops adjoining forest patches or other seminatural habitats than in crops completely surrounded by other crops. In this study, we investigated the specific importance of forest edges in providing potential pollinators in B. napus fields in two areas in France. Bees were caught with yellow pan traps at increasing distances from both warm and cold forest edges into B. napus fields during the blooming period. A total of 4594 individual bees, representing six families and 83 taxa, were collected. We found that both bee abundance and taxa richness were negatively affected by the distance from forest edge. However, responses varied between bee groups and edge orientations. The ITD (Inter-Tegular distance) of the species, a good proxy for bee foraging range, seems to limit how far the bees can travel from the forest edge. We found a greater abundance of cuckoo bees (Nomada spp.) of Andrena spp. and Andrena spp. males at forest edges, which we assume indicate suitable nesting sites, or at least mating sites, for some abundant Andrena species and their parasites (Fig. 1). Synthesis and Applications. This study provides one of the first examples in temperate ecosystems of how forest edges may actually act as a reservoir of potential pollinators and directly benefit agricultural crops by providing nesting or mating sites for important early spring pollinators. Policy-makers and land managers should take forest edges into account and encourage their protection in the agricultural matrix to promote wild bees and their pollination services. PMID:24634722

  1. Distance from forest edge affects bee pollinators in oilseed rape fields.

    PubMed

    Bailey, Samantha; Requier, Fabrice; Nusillard, Benoît; Roberts, Stuart P M; Potts, Simon G; Bouget, Christophe

    2014-02-01

    Wild pollinators have been shown to enhance the pollination of Brassica napus (oilseed rape) and thus increase its market value. Several studies have previously shown that pollination services are greater in crops adjoining forest patches or other seminatural habitats than in crops completely surrounded by other crops. In this study, we investigated the specific importance of forest edges in providing potential pollinators in B. napus fields in two areas in France. Bees were caught with yellow pan traps at increasing distances from both warm and cold forest edges into B. napus fields during the blooming period. A total of 4594 individual bees, representing six families and 83 taxa, were collected. We found that both bee abundance and taxa richness were negatively affected by the distance from forest edge. However, responses varied between bee groups and edge orientations. The ITD (Inter-Tegular distance) of the species, a good proxy for bee foraging range, seems to limit how far the bees can travel from the forest edge. We found a greater abundance of cuckoo bees (Nomada spp.) of Andrena spp. and Andrena spp. males at forest edges, which we assume indicate suitable nesting sites, or at least mating sites, for some abundant Andrena species and their parasites (Fig. 1). Synthesis and Applications. This study provides one of the first examples in temperate ecosystems of how forest edges may actually act as a reservoir of potential pollinators and directly benefit agricultural crops by providing nesting or mating sites for important early spring pollinators. Policy-makers and land managers should take forest edges into account and encourage their protection in the agricultural matrix to promote wild bees and their pollination services.

  2. Distance from forest edge affects bee pollinators in oilseed rape fields.

    PubMed

    Bailey, Samantha; Requier, Fabrice; Nusillard, Benoît; Roberts, Stuart P M; Potts, Simon G; Bouget, Christophe

    2014-02-01

    Wild pollinators have been shown to enhance the pollination of Brassica napus (oilseed rape) and thus increase its market value. Several studies have previously shown that pollination services are greater in crops adjoining forest patches or other seminatural habitats than in crops completely surrounded by other crops. In this study, we investigated the specific importance of forest edges in providing potential pollinators in B. napus fields in two areas in France. Bees were caught with yellow pan traps at increasing distances from both warm and cold forest edges into B. napus fields during the blooming period. A total of 4594 individual bees, representing six families and 83 taxa, were collected. We found that both bee abundance and taxa richness were negatively affected by the distance from forest edge. However, responses varied between bee groups and edge orientations. The ITD (Inter-Tegular distance) of the species, a good proxy for bee foraging range, seems to limit how far the bees can travel from the forest edge. We found a greater abundance of cuckoo bees (Nomada spp.) of Andrena spp. and Andrena spp. males at forest edges, which we assume indicate suitable nesting sites, or at least mating sites, for some abundant Andrena species and their parasites (Fig. 1). Synthesis and Applications. This study provides one of the first examples in temperate ecosystems of how forest edges may actually act as a reservoir of potential pollinators and directly benefit agricultural crops by providing nesting or mating sites for important early spring pollinators. Policy-makers and land managers should take forest edges into account and encourage their protection in the agricultural matrix to promote wild bees and their pollination services. PMID:24634722

  3. Orchid bee (Hymenoptera: Apidae) community from a gallery forest in the Brazilian Cerrado.

    PubMed

    Silva, Francinaldo S

    2012-06-01

    The orchid bees are a very important group of pollinators distributed in the Neotropics. Although a lot of studies concerning male euglossine bees have been done in this region, few works have so far been carried out in the Cerrado biome. This manuscript has the main objective to present the orchid bee community from a Gallery Forest in the Northeastern Brazilian Cerrado landscape, taking account the species composition, abundance, seasonality and hourly distribution. Male euglossine bees were collected monthly from October 2007 to May 2009, in the Reserva Florestal da Itamacaoca belonging to the Companhia de Agua e Esgoto do Maranhão, in Chapadinha municipality, Maranhão State. The scents eucalyptol, eugenol and vanillin were utilized, between 07:00 and 17:00hr, to attract the euglossine males. Cotton balls were dampened with the scents and suspended by a string on tree branches 1.5m above soil level, set 8m from one another. The specimens were captured with entomological nets, killed with ethyl acetate and transported to the laboratory to be identified. A total of 158 individuals and 14 species of bees were recorded. The genus Eulaema was the most representative group of euglossine bees in relation to the total number of the sampled individuals, accounting for 50.6% of bees followed by Euglossa (26.6%), Eufriesea (15.2%) and Exaerete (7.6%). The most frequent species were Eulaema nigrita (27.8%), Eulaema cingulara (19%) and Euglossa cordata (18.3%). Many species typical of forested environments were found in samples, like Euglossa avicula, Euglossa violaceifrons and Eulaema meriana, emphasizing the role played by the Gallery Forests as bridge sites to connect the two great biomes of Amazonia and Atlantic Forest. The occurrence of Exaerete guaykuru represents the second record of this species for the Neotropical region, and both records coming from the Gallery Forest zones. The male euglossine bees were sampled mainly in the dry season, where 62.5% of the

  4. Orchid bee (Hymenoptera: Apidae) community from a gallery forest in the Brazilian Cerrado.

    PubMed

    Silva, Francinaldo S

    2012-06-01

    The orchid bees are a very important group of pollinators distributed in the Neotropics. Although a lot of studies concerning male euglossine bees have been done in this region, few works have so far been carried out in the Cerrado biome. This manuscript has the main objective to present the orchid bee community from a Gallery Forest in the Northeastern Brazilian Cerrado landscape, taking account the species composition, abundance, seasonality and hourly distribution. Male euglossine bees were collected monthly from October 2007 to May 2009, in the Reserva Florestal da Itamacaoca belonging to the Companhia de Agua e Esgoto do Maranhão, in Chapadinha municipality, Maranhão State. The scents eucalyptol, eugenol and vanillin were utilized, between 07:00 and 17:00hr, to attract the euglossine males. Cotton balls were dampened with the scents and suspended by a string on tree branches 1.5m above soil level, set 8m from one another. The specimens were captured with entomological nets, killed with ethyl acetate and transported to the laboratory to be identified. A total of 158 individuals and 14 species of bees were recorded. The genus Eulaema was the most representative group of euglossine bees in relation to the total number of the sampled individuals, accounting for 50.6% of bees followed by Euglossa (26.6%), Eufriesea (15.2%) and Exaerete (7.6%). The most frequent species were Eulaema nigrita (27.8%), Eulaema cingulara (19%) and Euglossa cordata (18.3%). Many species typical of forested environments were found in samples, like Euglossa avicula, Euglossa violaceifrons and Eulaema meriana, emphasizing the role played by the Gallery Forests as bridge sites to connect the two great biomes of Amazonia and Atlantic Forest. The occurrence of Exaerete guaykuru represents the second record of this species for the Neotropical region, and both records coming from the Gallery Forest zones. The male euglossine bees were sampled mainly in the dry season, where 62.5% of the

  5. Mating frequencies of honey bee queens (Apis mellifera L.) in a population of feral colonies in the Northeastern United States.

    PubMed

    Tarpy, David R; Delaney, Deborah A; Seeley, Thomas D

    2015-01-01

    Across their introduced range in North America, populations of feral honey bee (Apis mellifera L.) colonies have supposedly declined in recent decades as a result of exotic parasites, most notably the ectoparasitic mite Varroa destructor. Nonetheless, recent studies have documented several wild populations of colonies that have persisted. The extreme polyandry of honey bee queens-and the increased intracolony genetic diversity it confers-has been attributed, in part, to improved disease resistance and may be a factor in the survival of these populations of feral colonies. We estimated the mating frequencies of queens in feral colonies in the Arnot Forest in New York State to determine if the level of polyandry of these queens is especially high and so might contribute to their survival success. We genotyped the worker offspring from 10 feral colonies in the Arnot Forest of upstate New York, as well as those from 20 managed colonies closest to this forest. We found no significant differences in mean mating frequency between the feral and managed queens, suggesting that queens in the remote, low-density population of colonies in the Arnot Forest are neither mate-limited nor adapted to mate at an especially high frequency. These findings support the hypothesis that the hyperpolyandry of honey bees has been shaped on an evolutionary timescale rather than on an ecological one.

  6. Mating Frequencies of Honey Bee Queens (Apis mellifera L.) in a Population of Feral Colonies in the Northeastern United States

    PubMed Central

    Tarpy, David R.; Delaney, Deborah A.; Seeley, Thomas D.

    2015-01-01

    Across their introduced range in North America, populations of feral honey bee (Apis mellifera L.) colonies have supposedly declined in recent decades as a result of exotic parasites, most notably the ectoparasitic mite Varroa destructor. Nonetheless, recent studies have documented several wild populations of colonies that have persisted. The extreme polyandry of honey bee queens—and the increased intracolony genetic diversity it confers—has been attributed, in part, to improved disease resistance and may be a factor in the survival of these populations of feral colonies. We estimated the mating frequencies of queens in feral colonies in the Arnot Forest in New York State to determine if the level of polyandry of these queens is especially high and so might contribute to their survival success. We genotyped the worker offspring from 10 feral colonies in the Arnot Forest of upstate New York, as well as those from 20 managed colonies closest to this forest. We found no significant differences in mean mating frequency between the feral and managed queens, suggesting that queens in the remote, low-density population of colonies in the Arnot Forest are neither mate-limited nor adapted to mate at an especially high frequency. These findings support the hypothesis that the hyperpolyandry of honey bees has been shaped on an evolutionary timescale rather than on an ecological one. PMID:25775410

  7. Population dynamics of Varroa destructor (Acari: Varroidae) in commercial honey bee colonies and implications for control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Treatment schedules to maintain low levels of Varroa mites in honey bee colonies were tested in hives started from either package bees or splits of larger colonies. The schedules were developed based on predictions of Varroa population growth generated from a mathematical model of honey bee colony ...

  8. Genetic diversity of Iranian honey bee (Apis mellifera meda Skorikow, 1829) populations based on ISSR markers.

    PubMed

    Rahimi, A; Mirmoayedi, A; Kahrizi, D; Zarei, L; Jamali, S

    2016-01-01

    Honey bee is one of the most important insects considering its role in agriculture,ecology and economy as a whole. In this study, the genetic diversity of different Iranian honey bee populations was evaluated using inter simple sequence repeat (ISSR) markers. During May to September 2014, 108 young worker honey bees were collected from six different populations in 30 different geoclimatic locations from Golestan, Mazendaran, Guilan, West Azerbaijan, East Azerbaijan, Ardebil provinces of Iran. DNA was extracted from the worker honey bees. The quality and quantity of extracted DNA were measured. A set of ten primers were screened with the laboratory populations of honey bees. The number of fragments produced in the different honey bee populations varied from 3 to 10, varying within 150 to 1500 bp. The used ten ISSR primers generated 40 polymorphic fragments, and the average heterozygosity for each primer was 0.266. Maximum numbers of bands were recorded for primer A1. A dendrogram based on the Unweighted Pair Group Method with Arithmetic mean (UPGMA) method generated two sub-clusters. Honey bee populations of Golestan, Mazendaran, Guilan provinces were located in the first group. The second group included honey bee populations of Ardebil, West Azerbaijan, East Azerbaijan provinces, but this group showed a close relationship with other populations. The results showed obviously the ability of the ISSR marker technique to detect the genetic diversity among the honey bee populations. PMID:27188735

  9. Genetic diversity of Iranian honey bee (Apis mellifera meda Skorikow, 1829) populations based on ISSR markers.

    PubMed

    Rahimi, A; Mirmoayedi, A; Kahrizi, D; Zarei, L; Jamali, S

    2016-04-30

    Honey bee is one of the most important insects considering its role in agriculture,ecology and economy as a whole. In this study, the genetic diversity of different Iranian honey bee populations was evaluated using inter simple sequence repeat (ISSR) markers. During May to September 2014, 108 young worker honey bees were collected from six different populations in 30 different geoclimatic locations from Golestan, Mazendaran, Guilan, West Azerbaijan, East Azerbaijan, Ardebil provinces of Iran. DNA was extracted from the worker honey bees. The quality and quantity of extracted DNA were measured. A set of ten primers were screened with the laboratory populations of honey bees. The number of fragments produced in the different honey bee populations varied from 3 to 10, varying within 150 to 1500 bp. The used ten ISSR primers generated 40 polymorphic fragments, and the average heterozygosity for each primer was 0.266. Maximum numbers of bands were recorded for primer A1. A dendrogram based on the Unweighted Pair Group Method with Arithmetic mean (UPGMA) method generated two sub-clusters. Honey bee populations of Golestan, Mazendaran, Guilan provinces were located in the first group. The second group included honey bee populations of Ardebil, West Azerbaijan, East Azerbaijan provinces, but this group showed a close relationship with other populations. The results showed obviously the ability of the ISSR marker technique to detect the genetic diversity among the honey bee populations.

  10. How Bees Deter Elephants: Beehive Trials with Forest Elephants (Loxodonta africana cyclotis) in Gabon.

    PubMed

    Ngama, Steeve; Korte, Lisa; Bindelle, Jérôme; Vermeulen, Cédric; Poulsen, John R

    2016-01-01

    In Gabon, like elsewhere in Africa, crops are often sources of conflict between humans and wildlife. Wildlife damage to crops can drastically reduce income, amplifying poverty and creating a negative perception of wild animal conservation among rural people. In this context, crop-raiding animals like elephants quickly become "problem animals". To deter elephants from raiding crops beehives have been successfully employed in East Africa; however, this method has not yet been tested in Central Africa. We experimentally examined whether the presence of Apis mellifera adansonii, the African honey bee species present in Central Africa, deters forest elephants (Loxodonta Africana cyclotis) from feeding on fruit trees. We show for the first time that the effectiveness of beehives as deterrents of elephants is related to bee activity. Empty hives and those housing colonies of low bee activity do not deter elephants all the time; but beehives with high bee activity do. Although elephant disturbance of hives does not impede honey production, there is a tradeoff between deterrence and the quantity of honey produced. To best achieve the dual goals of deterring elephants and producing honey colonies must maintain an optimum activity level of 40 to 60 bee movements per minute. Thus, beehives colonized by Apis mellifera adansonii bees can be effective elephant deterrents, but people must actively manage hives to maintain bee colonies at the optimum activity level.

  11. How Bees Deter Elephants: Beehive Trials with Forest Elephants (Loxodonta africana cyclotis) in Gabon.

    PubMed

    Ngama, Steeve; Korte, Lisa; Bindelle, Jérôme; Vermeulen, Cédric; Poulsen, John R

    2016-01-01

    In Gabon, like elsewhere in Africa, crops are often sources of conflict between humans and wildlife. Wildlife damage to crops can drastically reduce income, amplifying poverty and creating a negative perception of wild animal conservation among rural people. In this context, crop-raiding animals like elephants quickly become "problem animals". To deter elephants from raiding crops beehives have been successfully employed in East Africa; however, this method has not yet been tested in Central Africa. We experimentally examined whether the presence of Apis mellifera adansonii, the African honey bee species present in Central Africa, deters forest elephants (Loxodonta Africana cyclotis) from feeding on fruit trees. We show for the first time that the effectiveness of beehives as deterrents of elephants is related to bee activity. Empty hives and those housing colonies of low bee activity do not deter elephants all the time; but beehives with high bee activity do. Although elephant disturbance of hives does not impede honey production, there is a tradeoff between deterrence and the quantity of honey produced. To best achieve the dual goals of deterring elephants and producing honey colonies must maintain an optimum activity level of 40 to 60 bee movements per minute. Thus, beehives colonized by Apis mellifera adansonii bees can be effective elephant deterrents, but people must actively manage hives to maintain bee colonies at the optimum activity level. PMID:27196059

  12. How Bees Deter Elephants: Beehive Trials with Forest Elephants (Loxodonta africana cyclotis) in Gabon

    PubMed Central

    Ngama, Steeve; Korte, Lisa; Bindelle, Jérôme; Vermeulen, Cédric; Poulsen, John R.

    2016-01-01

    In Gabon, like elsewhere in Africa, crops are often sources of conflict between humans and wildlife. Wildlife damage to crops can drastically reduce income, amplifying poverty and creating a negative perception of wild animal conservation among rural people. In this context, crop-raiding animals like elephants quickly become “problem animals”. To deter elephants from raiding crops beehives have been successfully employed in East Africa; however, this method has not yet been tested in Central Africa. We experimentally examined whether the presence of Apis mellifera adansonii, the African honey bee species present in Central Africa, deters forest elephants (Loxodonta Africana cyclotis) from feeding on fruit trees. We show for the first time that the effectiveness of beehives as deterrents of elephants is related to bee activity. Empty hives and those housing colonies of low bee activity do not deter elephants all the time; but beehives with high bee activity do. Although elephant disturbance of hives does not impede honey production, there is a tradeoff between deterrence and the quantity of honey produced. To best achieve the dual goals of deterring elephants and producing honey colonies must maintain an optimum activity level of 40 to 60 bee movements per minute. Thus, beehives colonized by Apis mellifera adansonii bees can be effective elephant deterrents, but people must actively manage hives to maintain bee colonies at the optimum activity level. PMID:27196059

  13. High bee and wasp diversity in a heterogeneous tropical farming system compared to protected forest.

    PubMed

    Schüepp, Christof; Rittiner, Sarah; Entling, Martin H

    2012-01-01

    It is a globally important challenge to meet increasing demands for resources and, at the same time, protect biodiversity and ecosystem services. Farming is usually regarded as a major threat to biodiversity due to its expansion into natural areas. We compared biodiversity of bees and wasps between heterogeneous small-scale farming areas and protected forest in northern coastal Belize, Central America. Malaise traps operated for three months during the transition from wet to dry season. Farming areas consisted of a mosaic of mixed crop types, open habitat, secondary forest, and agroforestry. Mean species richness per site (alpha diversity), as well as spatial and temporal community variation (beta diversity) of bees and wasps were equal or higher in farming areas compared to protected forest. The higher species richness and community variation in farmland was due to additional species that did not occur in the forest, whereas most species trapped in forest were also found in farming areas. The overall regional species richness (gamma diversity) increased by 70% with the inclusion of farming areas. Our results suggest that small-scale farming systems adjacent to protected forest may not only conserve, but even favour, biodiversity of some taxonomic groups. We can, however, not exclude possible declines of bee and wasp diversity in more intensified farmland or in landscapes completely covered by heterogeneous farming systems.

  14. Population structure of honey bees in the Carpathian Basin (Hungary) confirms introgression from surrounding subspecies.

    PubMed

    Péntek-Zakar, Erika; Oleksa, Andrzej; Borowik, Tomasz; Kusza, Szilvia

    2015-12-01

    Carniolan honey bees (Apis mellifera carnica) are considered as an indigenous subspecies in Hungary adapted to most of the ecological and climatic conditions in this area. However, during the last decades Hungarian beekeepers have recognized morphological signs of the Italian honey bee (Apis mellifera ligustica). As the natural distribution of the honey bee subspecies can be affected by the importation of honey bee queens or by natural gene flow, we aimed at determining the genetic structure and characteristics of the local honey bee population using molecular markers. All together, 48 Hungarian and 84 foreign (Italian, Polish, Spanish, Liberian) pupae and/or workers were used for mitochondrial DNA analysis. Additionally, 53 sequences corresponding to 10 subspecies and the Buckfast hybrid were downloaded from GenBank. For the nuclear analysis, 236 Hungarian and 106 foreign honey bees were genotyped using nine microsatellites. Heterozygosity values, population-specific alleles, FST values, principal coordinate analysis, assignment tests, structure analysis, and dendrograms were calculated. Haplotype and nucleotide diversity values showed moderate values. We found that one haplotype (H9) was dominant in Hungary. The presence of the black honey bee (Apis mellifera mellifera) was negligible, but a few individuals resembling other subspecies were identified. We proved that the Hungarian honey bee population is nearly homogeneous but also demonstrated introgression from the foreign subspecies. Both mitochondrial DNA and microsatellite analyses corroborated the observations of the beekeepers. Molecular analyses suggested that Carniolan honey bee in Hungary is slightly affected by Italian and black honey bee introgression. Genetic differences were detected between Polish and Hungarian Carniolan honey bee populations, suggesting the existence of at least two different gene pools within A. m. carnica.

  15. Population structure of honey bees in the Carpathian Basin (Hungary) confirms introgression from surrounding subspecies.

    PubMed

    Péntek-Zakar, Erika; Oleksa, Andrzej; Borowik, Tomasz; Kusza, Szilvia

    2015-12-01

    Carniolan honey bees (Apis mellifera carnica) are considered as an indigenous subspecies in Hungary adapted to most of the ecological and climatic conditions in this area. However, during the last decades Hungarian beekeepers have recognized morphological signs of the Italian honey bee (Apis mellifera ligustica). As the natural distribution of the honey bee subspecies can be affected by the importation of honey bee queens or by natural gene flow, we aimed at determining the genetic structure and characteristics of the local honey bee population using molecular markers. All together, 48 Hungarian and 84 foreign (Italian, Polish, Spanish, Liberian) pupae and/or workers were used for mitochondrial DNA analysis. Additionally, 53 sequences corresponding to 10 subspecies and the Buckfast hybrid were downloaded from GenBank. For the nuclear analysis, 236 Hungarian and 106 foreign honey bees were genotyped using nine microsatellites. Heterozygosity values, population-specific alleles, FST values, principal coordinate analysis, assignment tests, structure analysis, and dendrograms were calculated. Haplotype and nucleotide diversity values showed moderate values. We found that one haplotype (H9) was dominant in Hungary. The presence of the black honey bee (Apis mellifera mellifera) was negligible, but a few individuals resembling other subspecies were identified. We proved that the Hungarian honey bee population is nearly homogeneous but also demonstrated introgression from the foreign subspecies. Both mitochondrial DNA and microsatellite analyses corroborated the observations of the beekeepers. Molecular analyses suggested that Carniolan honey bee in Hungary is slightly affected by Italian and black honey bee introgression. Genetic differences were detected between Polish and Hungarian Carniolan honey bee populations, suggesting the existence of at least two different gene pools within A. m. carnica. PMID:27069597

  16. Bee

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bee, Claire Preston, is a book written generally for the layperson, but may be of interest to those working in entomology. This review seeks to help entomologists who may have interest in the subject to decide whether or not to invest time into reading the book. The review is generally positive an...

  17. Orchid bee fauna (Hymenoptera: Apidae: Euglossina) of Atlantic Forest fragments inside an urban area in southeastern Brazil.

    PubMed

    Nemésio, André; Silveira, Fernando A

    2007-01-01

    Male orchid bees were collected by chemical baiting in four forest fragments in parks of the city of Belo Horizonte, Minas Gerais, southeastern Brazil. One thousand three hundred and twenty-five males belonging to 14 species were captured within one year. The capture data were compared through correlation tests. The data suggest that abundance of orchid bees tend to increase with fragment size, although no correlation between species richness and fragment size was obtained. The results presented herein suggest that forest fragments in a large city may be of importance concerning conservation of orchid-bee faunas.

  18. Phylogeography of Partamona rustica (Hymenoptera, Apidae), an Endemic Stingless Bee from the Neotropical Dry Forest Diagonal

    PubMed Central

    Batalha-Filho, Henrique; Congrains, Carlos; Carvalho, Antônio Freire; Ferreira, Kátia Maria; Del Lama, Marco Antonio

    2016-01-01

    The South America encompasses the highest levels of biodiversity found anywhere in the world and its rich biota is distributed among many different biogeographical regions. However, many regions of South America are still poorly studied, including its xeric environments, such as the threatened Caatinga and Cerrado phytogeographical domains. In particular, the effects of Quaternary climatic events on the demography of endemic species from xeric habitats are poorly understood. The present study uses an integrative approach to reconstruct the evolutionary history of Partamona rustica, an endemic stingless bee from dry forest diagonal in Brazil, in a spatial-temporal framework. In this sense, we sequenced four mitochondrial genes and genotyped eight microsatellite loci. Our results identified two population groups: one to the west and the other to the east of the São Francisco River Valley (SFRV). These groups split in the late Pleistocene, and the Approximate Bayesian Computation approach and phylogenetic reconstruction indicated that P. rustica originated in the west of the SFRV, subsequently colonising eastern region. Our tests of migration detected reduced gene flow between these groups. Finally, our results also indicated that the inferences both from the genetic data analyses and from the spatial distribution modelling are compatible with historical demographic stability. PMID:27723778

  19. Behavioral Ecology of Euglossine Bees of the Atlantic Rain Forest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Before the colonization of Brazil, the Atlantic Forest extended from Rio Grande do Norte to Rio Grande do Sul. As recently as 1832, Charles Darwin described it as "a forest which in the grandeur of all its parts could not be exceeded." It is now highly fragmented and only 8% of its former size, wi...

  20. [The gallery forests of the São Francisco river as corridors for Euglossine bees (Hymenoptera: Apidae) from tropical rainforests].

    PubMed

    Moura, Debora C; Schlindwein, Clemens

    2009-01-01

    Euglossini are typical bees of Neotropical rainforests and only a few species occur in the Caatinga. The São Francisco river, which is the only permanent river in the semi-arid NE-Brazil, is bordered by a gallery forest with evergreen leaves. This environment offers flooral rewards along the year. Surveys of euglossine bees by attracting males to scent baits showed that species of the Atlantic Rainforest like Euglossa imperialis Cockerel, E. truncata Moure and Eulaema cingulata Fabricius occur in the gallery forest of the São Francisco river under the semi-arid climate of the caatinga region. These bees are restricted to the gallery forests which function as bio-corridors, and are absent at places where the forests were cut down. This emphasizes the need to protect the threatened gallery forests to maintain biodiversity. PMID:19488520

  1. [The gallery forests of the São Francisco river as corridors for Euglossine bees (Hymenoptera: Apidae) from tropical rainforests].

    PubMed

    Moura, Debora C; Schlindwein, Clemens

    2009-01-01

    Euglossini are typical bees of Neotropical rainforests and only a few species occur in the Caatinga. The São Francisco river, which is the only permanent river in the semi-arid NE-Brazil, is bordered by a gallery forest with evergreen leaves. This environment offers flooral rewards along the year. Surveys of euglossine bees by attracting males to scent baits showed that species of the Atlantic Rainforest like Euglossa imperialis Cockerel, E. truncata Moure and Eulaema cingulata Fabricius occur in the gallery forest of the São Francisco river under the semi-arid climate of the caatinga region. These bees are restricted to the gallery forests which function as bio-corridors, and are absent at places where the forests were cut down. This emphasizes the need to protect the threatened gallery forests to maintain biodiversity.

  2. High population variability and source-sink dynamics in a solitary bee species.

    PubMed

    Franzén, Markus; Nilsson, Sven G

    2013-06-01

    Although solitary bees are considered to play key roles in ecosystem functions, surprisingly few studies have explored their population dynamics. We investigated the population dynamics of a rare, declining, solitary bee (Andrena humilis) in a landscape of 80 km2 in southern Sweden from 2003 to 2011. Only one population was persistent throughout all years studied; most likely this population supplied the surrounding landscape with 11 smaller, temporary local populations. Despite stable pollen availability, the size of the persistent population fluctuated dramatically in a two-year cycle over the nine years, with 490-1230 nests in odd-numbered years and 21-48 nests in even-numbered years. These fluctuations were not significantly related to climatic variables or pollen availability. Nineteen colonization and 14 extinction events were recorded. Occupancy decreased with distance from the persistent population and increased with increasing resource (pollen) availability. There were significant positive correlations between the size of the persistent population and patch occupancy and colonization. Colonizations were generally more common in patches closer to the persistent population, whereas extinctions were independent of distance from the persistent population. Our results highlight the complex population dynamics that exist for this solitary bee species, which could be due to source-sink dynamics, a prolonged diapause, or can represent a bet-hedging strategy to avoid natural enemies and survive in small habitat patches. If large fluctuations in solitary bee populations prove to be widespread, it will have important implications for interpreting ecological relationships, bee conservation, and pollination.

  3. Bidirectional transfer of RNAi between honey bee and Varroa destructor: Varroa gene silencing reduces Varroa population.

    PubMed

    Garbian, Yael; Maori, Eyal; Kalev, Haim; Shafir, Sharoni; Sela, Ilan

    2012-12-01

    The mite Varroa destructor is an obligatory ectoparasite of the honey bee (Apis mellifera) and is one of the major threats to apiculture worldwide. We previously reported that honey bees fed on double-stranded RNA (dsRNA) with a sequence homologous to that of the Israeli acute paralysis virus are protected from the viral disease. Here we show that dsRNA ingested by bees is transferred to the Varroa mite and from mite on to a parasitized bee. This cross-species, reciprocal exchange of dsRNA between bee and Varroa engendered targeted gene silencing in the latter, and resulted in an over 60% decrease in the mite population. Thus, transfer of gene-silencing-triggering molecules between this invertebrate host and its ectoparasite could lead to a conceptually novel approach to Varroa control.

  4. Bidirectional Transfer of RNAi between Honey Bee and Varroa destructor: Varroa Gene Silencing Reduces Varroa Population

    PubMed Central

    Kalev, Haim; Shafir, Sharoni; Sela, Ilan

    2012-01-01

    The mite Varroa destructor is an obligatory ectoparasite of the honey bee (Apis mellifera) and is one of the major threats to apiculture worldwide. We previously reported that honey bees fed on double-stranded RNA (dsRNA) with a sequence homologous to that of the Israeli acute paralysis virus are protected from the viral disease. Here we show that dsRNA ingested by bees is transferred to the Varroa mite and from mite on to a parasitized bee. This cross-species, reciprocal exchange of dsRNA between bee and Varroa engendered targeted gene silencing in the latter, and resulted in an over 60% decrease in the mite population. Thus, transfer of gene-silencing-triggering molecules between this invertebrate host and its ectoparasite could lead to a conceptually novel approach to Varroa control. PMID:23308063

  5. Communities of Social Bees (Apidae: Meliponini) in Trap-Nests: the Spatial Dynamics of Reproduction in an Area of Atlantic Forest.

    PubMed

    Silva, M D; Ramalho, M; Monteiro, D

    2014-08-01

    As most stingless bee species depend on preexisting cavities, principally tree hollows, nesting site availability may represent an important restriction in the structuring of their forest communities. The present study examined the spatial dynamics of stingless bee communities in an area of Atlantic Forest by evaluating their swarming to trap-nests. The field work was performed in the Michelin Ecological Reserve (MER) on the southeastern coast of the state of Bahia, Brazil. Seven hundred and twenty trap-nests were distributed within two forest habitats in advanced and initial stages of regeneration. The trap-nests were monitored between September 2009 and March 2011. Twenty-five trap-nests were occupied by five bee species, resulting in a capture ratio of 0.035 swarms/trap (approximately 0.14 swarms/ha), corresponding to 10 swarms/year (0.056 swarms/ha/year). According to previous study at MER, the most abundant species in natural nests were also the most common in trap-nests in the two forest habitats examined, with the exception of Melipona scutellaris Latreille. Swarms of higher numbers of species were captured in initial regeneration stage forests than in advanced regeneration stage areas, and differences in species compositions were significant between both habitats (p = 0.03); these apparent differences were not consistent, however, when considering richness (p = 0.14) and total abundance (p = 0.08). The present study suggests the existence of a minimum cavity size threshold of approximately 1 L for most local species of stingless bees and sustains the hypothesis of a mass effect of Tetragonisca angustula Latreille populations from surrounding disturbed habitats on the MER forest community in terms of propagule (swarm) pressure. Examining swarm densities with trap-nests can be a promising technique for comparative analyses of the carrying capacities of forest habitats for stingless bee colonies, as long as size thresholds of cavities for nesting

  6. Communities of Social Bees (Apidae: Meliponini) in Trap-Nests: the Spatial Dynamics of Reproduction in an Area of Atlantic Forest.

    PubMed

    Silva, M D; Ramalho, M; Monteiro, D

    2014-08-01

    As most stingless bee species depend on preexisting cavities, principally tree hollows, nesting site availability may represent an important restriction in the structuring of their forest communities. The present study examined the spatial dynamics of stingless bee communities in an area of Atlantic Forest by evaluating their swarming to trap-nests. The field work was performed in the Michelin Ecological Reserve (MER) on the southeastern coast of the state of Bahia, Brazil. Seven hundred and twenty trap-nests were distributed within two forest habitats in advanced and initial stages of regeneration. The trap-nests were monitored between September 2009 and March 2011. Twenty-five trap-nests were occupied by five bee species, resulting in a capture ratio of 0.035 swarms/trap (approximately 0.14 swarms/ha), corresponding to 10 swarms/year (0.056 swarms/ha/year). According to previous study at MER, the most abundant species in natural nests were also the most common in trap-nests in the two forest habitats examined, with the exception of Melipona scutellaris Latreille. Swarms of higher numbers of species were captured in initial regeneration stage forests than in advanced regeneration stage areas, and differences in species compositions were significant between both habitats (p = 0.03); these apparent differences were not consistent, however, when considering richness (p = 0.14) and total abundance (p = 0.08). The present study suggests the existence of a minimum cavity size threshold of approximately 1 L for most local species of stingless bees and sustains the hypothesis of a mass effect of Tetragonisca angustula Latreille populations from surrounding disturbed habitats on the MER forest community in terms of propagule (swarm) pressure. Examining swarm densities with trap-nests can be a promising technique for comparative analyses of the carrying capacities of forest habitats for stingless bee colonies, as long as size thresholds of cavities for nesting

  7. Effects of Infection on Honey Bee Population Dynamics: A Model

    PubMed Central

    Betti, Matt I.; Wahl, Lindi M.; Zamir, Mair

    2014-01-01

    We propose a model that combines the dynamics of the spread of disease within a bee colony with the underlying demographic dynamics of the colony to determine the ultimate fate of the colony under different scenarios. The model suggests that key factors in the survival or collapse of a honey bee colony in the face of an infection are the rate of transmission of the infection and the disease-induced death rate. An increase in the disease-induced death rate, which can be thought of as an increase in the severity of the disease, may actually help the colony overcome the disease and survive through winter. By contrast, an increase in the transmission rate, which means that bees are being infected at an earlier age, has a drastic deleterious effect. Another important finding relates to the timing of infection in relation to the onset of winter, indicating that in a time interval of approximately 20 days before the onset of winter the colony is most affected by the onset of infection. The results suggest further that the age of recruitment of hive bees to foraging duties is a good early marker for the survival or collapse of a honey bee colony in the face of infection, which is consistent with experimental evidence but the model provides insight into the underlying mechanisms. The most important result of the study is a clear distinction between an exposure of the honey bee colony to an environmental hazard such as pesticides or insecticides, or an exposure to an infectious disease. The results indicate unequivocally that in the scenarios that we have examined, and perhaps more generally, an infectious disease is far more hazardous to the survival of a bee colony than an environmental hazard that causes an equal death rate in foraging bees. PMID:25329468

  8. Effects of infection on honey bee population dynamics: a model.

    PubMed

    Betti, Matt I; Wahl, Lindi M; Zamir, Mair

    2014-01-01

    We propose a model that combines the dynamics of the spread of disease within a bee colony with the underlying demographic dynamics of the colony to determine the ultimate fate of the colony under different scenarios. The model suggests that key factors in the survival or collapse of a honey bee colony in the face of an infection are the rate of transmission of the infection and the disease-induced death rate. An increase in the disease-induced death rate, which can be thought of as an increase in the severity of the disease, may actually help the colony overcome the disease and survive through winter. By contrast, an increase in the transmission rate, which means that bees are being infected at an earlier age, has a drastic deleterious effect. Another important finding relates to the timing of infection in relation to the onset of winter, indicating that in a time interval of approximately 20 days before the onset of winter the colony is most affected by the onset of infection. The results suggest further that the age of recruitment of hive bees to foraging duties is a good early marker for the survival or collapse of a honey bee colony in the face of infection, which is consistent with experimental evidence but the model provides insight into the underlying mechanisms. The most important result of the study is a clear distinction between an exposure of the honey bee colony to an environmental hazard such as pesticides or insecticides, or an exposure to an infectious disease. The results indicate unequivocally that in the scenarios that we have examined, and perhaps more generally, an infectious disease is far more hazardous to the survival of a bee colony than an environmental hazard that causes an equal death rate in foraging bees.

  9. Sudden deaths and colony population decline in Greek honey bee colonies.

    PubMed

    Bacandritsos, N; Granato, A; Budge, G; Papanastasiou, I; Roinioti, E; Caldon, M; Falcaro, C; Gallina, A; Mutinelli, F

    2010-11-01

    During June and July of 2009, sudden deaths, tremulous movements and population declines of adult honey bees were reported by the beekeepers in the region of Peloponnesus (Mt. Mainalo), Greece. A preliminary study was carried out to investigate these unexplained phenomena in this region. In total, 37 bee samples, two brood frames containing honey bee brood of various ages, eight sugar samples and four sugar patties were collected from the affected colonies. The samples were tested for a range of pests, pathogens and pesticides. Symptomatic adult honey bees tested positive for Varroa destructor, Nosema ceranae, Chronic bee paralysis virus (CBPV), Acute paralysis virus (ABPV), Deformed wing virus (DWV), Sacbrood virus (SBV) and Black queen cell virus (BQCV), but negative for Acarapis woodi. American Foulbrood was absent from the brood samples. Chemical analysis revealed that amitraz, thiametoxan, clothianidin and acetamiprid were all absent from symptomatic adult bees, sugar and sugar patty samples. However, some bee samples, were contaminated with imidacloprid in concentrations between 14 ng/g and 39 ng/g tissue. We present: the infection of Greek honey bees by multiple viruses; the presence of N. ceranae in Greek honey bees and the first record of imidacloprid (neonicotonoid) residues in Greek honey bee tissues. The presence of multiple pathogens and pesticides made it difficult to associate a single specific cause to the depopulation phenomena observed in Greece, although we believe that viruses and N. ceranae synergistically played the most important role. A follow-up in-depth survey across all Greek regions is required to provide context to these preliminary findings.

  10. Sudden deaths and colony population decline in Greek honey bee colonies.

    PubMed

    Bacandritsos, N; Granato, A; Budge, G; Papanastasiou, I; Roinioti, E; Caldon, M; Falcaro, C; Gallina, A; Mutinelli, F

    2010-11-01

    During June and July of 2009, sudden deaths, tremulous movements and population declines of adult honey bees were reported by the beekeepers in the region of Peloponnesus (Mt. Mainalo), Greece. A preliminary study was carried out to investigate these unexplained phenomena in this region. In total, 37 bee samples, two brood frames containing honey bee brood of various ages, eight sugar samples and four sugar patties were collected from the affected colonies. The samples were tested for a range of pests, pathogens and pesticides. Symptomatic adult honey bees tested positive for Varroa destructor, Nosema ceranae, Chronic bee paralysis virus (CBPV), Acute paralysis virus (ABPV), Deformed wing virus (DWV), Sacbrood virus (SBV) and Black queen cell virus (BQCV), but negative for Acarapis woodi. American Foulbrood was absent from the brood samples. Chemical analysis revealed that amitraz, thiametoxan, clothianidin and acetamiprid were all absent from symptomatic adult bees, sugar and sugar patty samples. However, some bee samples, were contaminated with imidacloprid in concentrations between 14 ng/g and 39 ng/g tissue. We present: the infection of Greek honey bees by multiple viruses; the presence of N. ceranae in Greek honey bees and the first record of imidacloprid (neonicotonoid) residues in Greek honey bee tissues. The presence of multiple pathogens and pesticides made it difficult to associate a single specific cause to the depopulation phenomena observed in Greece, although we believe that viruses and N. ceranae synergistically played the most important role. A follow-up in-depth survey across all Greek regions is required to provide context to these preliminary findings. PMID:20804765

  11. Bird Populations in Fernbank Forest: MIGRANT SPECIES.

    ERIC Educational Resources Information Center

    Schmalz, Georgann

    1991-01-01

    This article discusses fragmented forests in general and provides arrival/departure data about migratory birds collected at Fernbank Forest which is located within metropolitan Atlanta. The data indicate that population trends for selected species have not changed over 19 years of migration recordings within this small, but important, fragmented…

  12. Impacts of neonicotinoid use on long-term population changes in wild bees in England

    NASA Astrophysics Data System (ADS)

    Woodcock, Ben A.; Isaac, Nicholas J. B.; Bullock, James M.; Roy, David B.; Garthwaite, David G.; Crowe, Andrew; Pywell, Richard F.

    2016-08-01

    Wild bee declines have been ascribed in part to neonicotinoid insecticides. While short-term laboratory studies on commercially bred species (principally honeybees and bumblebees) have identified sub-lethal effects, there is no strong evidence linking these insecticides to losses of the majority of wild bee species. We relate 18 years of UK national wild bee distribution data for 62 species to amounts of neonicotinoid use in oilseed rape. Using a multi-species dynamic Bayesian occupancy analysis, we find evidence of increased population extinction rates in response to neonicotinoid seed treatment use on oilseed rape. Species foraging on oilseed rape benefit from the cover of this crop, but were on average three times more negatively affected by exposure to neonicotinoids than non-crop foragers. Our results suggest that sub-lethal effects of neonicotinoids could scale up to cause losses of bee biodiversity. Restrictions on neonicotinoid use may reduce population declines.

  13. Impacts of neonicotinoid use on long-term population changes in wild bees in England.

    PubMed

    Woodcock, Ben A; Isaac, Nicholas J B; Bullock, James M; Roy, David B; Garthwaite, David G; Crowe, Andrew; Pywell, Richard F

    2016-08-16

    Wild bee declines have been ascribed in part to neonicotinoid insecticides. While short-term laboratory studies on commercially bred species (principally honeybees and bumblebees) have identified sub-lethal effects, there is no strong evidence linking these insecticides to losses of the majority of wild bee species. We relate 18 years of UK national wild bee distribution data for 62 species to amounts of neonicotinoid use in oilseed rape. Using a multi-species dynamic Bayesian occupancy analysis, we find evidence of increased population extinction rates in response to neonicotinoid seed treatment use on oilseed rape. Species foraging on oilseed rape benefit from the cover of this crop, but were on average three times more negatively affected by exposure to neonicotinoids than non-crop foragers. Our results suggest that sub-lethal effects of neonicotinoids could scale up to cause losses of bee biodiversity. Restrictions on neonicotinoid use may reduce population declines.

  14. Impacts of neonicotinoid use on long-term population changes in wild bees in England

    PubMed Central

    Woodcock, Ben A.; Isaac, Nicholas J. B.; Bullock, James M.; Roy, David B.; Garthwaite, David G.; Crowe, Andrew; Pywell, Richard F.

    2016-01-01

    Wild bee declines have been ascribed in part to neonicotinoid insecticides. While short-term laboratory studies on commercially bred species (principally honeybees and bumblebees) have identified sub-lethal effects, there is no strong evidence linking these insecticides to losses of the majority of wild bee species. We relate 18 years of UK national wild bee distribution data for 62 species to amounts of neonicotinoid use in oilseed rape. Using a multi-species dynamic Bayesian occupancy analysis, we find evidence of increased population extinction rates in response to neonicotinoid seed treatment use on oilseed rape. Species foraging on oilseed rape benefit from the cover of this crop, but were on average three times more negatively affected by exposure to neonicotinoids than non-crop foragers. Our results suggest that sub-lethal effects of neonicotinoids could scale up to cause losses of bee biodiversity. Restrictions on neonicotinoid use may reduce population declines. PMID:27529661

  15. Impacts of neonicotinoid use on long-term population changes in wild bees in England.

    PubMed

    Woodcock, Ben A; Isaac, Nicholas J B; Bullock, James M; Roy, David B; Garthwaite, David G; Crowe, Andrew; Pywell, Richard F

    2016-01-01

    Wild bee declines have been ascribed in part to neonicotinoid insecticides. While short-term laboratory studies on commercially bred species (principally honeybees and bumblebees) have identified sub-lethal effects, there is no strong evidence linking these insecticides to losses of the majority of wild bee species. We relate 18 years of UK national wild bee distribution data for 62 species to amounts of neonicotinoid use in oilseed rape. Using a multi-species dynamic Bayesian occupancy analysis, we find evidence of increased population extinction rates in response to neonicotinoid seed treatment use on oilseed rape. Species foraging on oilseed rape benefit from the cover of this crop, but were on average three times more negatively affected by exposure to neonicotinoids than non-crop foragers. Our results suggest that sub-lethal effects of neonicotinoids could scale up to cause losses of bee biodiversity. Restrictions on neonicotinoid use may reduce population declines. PMID:27529661

  16. Hedgerow restoration promotes pollinator populations and exports native bees to adjacent fields.

    PubMed

    Morandin, Lora A; Kremen, Claire

    2013-06-01

    In intensive agricultural landscapes, restoration within farms could enhance biodiversity and ecosystem services such as pollination by native pollinators. Although governments and conservation groups are promoting small-scale restoration on working farms, there are few studies that assess whether these practices enhance pollinator communities in restored areas. Further, there is no information on whether floral enhancements will deplete pollinators in adjacent fields by concentrating ambient populations or whether they result in a net increase in abundance in adjacent farm fields. We investigated whether field edges restored with native perennial plants in California's Central Valley agricultural region increased floral abundance and potential bee nesting sites, and native bee and syrphid fly abundance and diversity, in comparison to relatively unmanaged edges. Native bees and syrphid flies collected from flowers were more abundant, species-rich, and diverse at hedgerow sites than in weedy, unmanaged edges. Abundance of bees collected passively in pan traps was negatively correlated with floral abundance, was significantly different from communities captured by net sampling from flowers, and did not distinguish between site types; we therefore focused on the results of net samples and visual observations. Uncommon species of native bees were sevenfold more abundant on hedgerow flowers than on flowers at weedy, unmanaged edges. Of the species on flowers at hedgerows, 40% were exclusive to hedgerow sites, but there were no species exclusively found on flowers at control sites. Hedgerows were especially important for supporting less-common species of native bees in our intensive agricultural landscape. Hedgerows did not concentrate ambient native bee, honey bee, or syphid fly populations, and they acted as net exporters of native bees into adjacent fields. Within-farm habitat restoration such as hedgerow creation may be essential for enhancing native pollinator

  17. Genetic structure of the gentle Africanized honey bee population (gAHB) in Puerto Rico

    PubMed Central

    2013-01-01

    Background The Africanized honey bee is one of the most spectacular invasions in the Americas. African bees escaped from apiaries in Brazil in 1956, spread over Americas and by 1994 they were reported in Puerto Rico. In contrast to other places, the oceanic island conditions in Puerto Rico may mean a single introduction and different dynamics of the resident European and new-coming Africanized bees. To examine the genetic variation of honey bee feral populations and colonies from different locations in Puerto Rico, we used eight known polymorphic microsatellite loci. Results In Puerto Rico, gAHB population does not show any genetic structure (Fst = 0.0783), and is best described as one honey bee population, product of hybridization of AHB and EHB. The genetic variability in this Africanized population was similar to that reported in studies from Texas. We observed that European private allele frequencies are high in all but one locus. This contrasts with mainland Africanized populations, where European allele frequencies are diminished. Two loci with European private alleles, one on Linkage Group 7, known to carry two known defensiveness Quantitative Trait Loci (QTLs), and the other on Linkage Group 1, known to carry three functionally studied genes and 11 candidate genes associated with Varroa resistance mechanisms were respectively, significantly greater or lower in European allele frequency than the other loci with European private alleles. Conclusions Genetic structure of Puerto Rico gAHB differs from mainland AHB populations, probably representing evolutionary processes on the island. PMID:23915100

  18. Landscape effects on extremely fragmented populations of a rare solitary bee, Colletes floralis.

    PubMed

    Davis, Emily S; Murray, Tomás E; Fitzpatrick, Una; Brown, Mark J F; Paxton, Robert J

    2010-11-01

    Globally, there is concern over the decline of bees, an ecologically important group of pollinating insects. Genetic studies provide insights into population structure that are crucial for conservation management but that would be impossible to obtain by conventional ecological methods. Yet conservation genetic studies of bees have primarily focussed on social species rather than the more species-rich solitary bees. Here, we investigate the population structure of Colletes floralis, a rare and threatened solitary mining bee, in Ireland and Scotland using nine microsatellite loci. Genetic diversity was surprisingly as high in Scottish (Hebridean island) populations at the extreme northwestern edge of the species range as in mainland Irish populations further south. Extremely high genetic differentiation among populations was detected; multilocus F(ST) was up to 0.53, and and D(est) were even higher (maximum: 0.85 and 1.00, respectively). A pattern of isolation by distance was evident for sites separated by land. Water appears to act as a substantial barrier to gene flow yet sites separated by sea did not exhibit isolation by distance. C. floralis populations are extremely isolated and probably not in regional migration-drift equilibrium. GIS-based landscape genetic analysis reveals urban areas as a potential and substantial barrier to gene flow. Our results highlight the need for urgent site-specific management action to halt the decline of this and potentially other rare solitary bees. PMID:21040051

  19. Field populations of native Indian honey bees from pesticide intensive agricultural landscape show signs of impaired olfaction.

    PubMed

    Chakrabarti, Priyadarshini; Rana, Santanu; Bandopadhyay, Sreejata; Naik, Dattatraya G; Sarkar, Sagartirtha; Basu, Parthiba

    2015-07-27

    Little information is available regarding the adverse effects of pesticides on natural honey bee populations. This study highlights the detrimental effects of pesticides on honey bee olfaction through behavioural studies, scanning electron microscopic imaging of antennal sensillae and confocal microscopic studies of honey bee brains for calcium ions on Apis cerana, a native Indian honey bee species. There was a significant decrease in proboscis extension response and biologically active free calcium ions and adverse changes in antennal sensillae in pesticide exposed field honey bee populations compared to morphometrically similar honey bees sampled from low/no pesticide sites. Controlled laboratory experiments corroborated these findings. This study reports for the first time the changes in antennal sensillae, expression of Calpain 1(an important calcium binding protein) and resting state free calcium in brains of honey bees exposed to pesticide stress.

  20. Field populations of native Indian honey bees from pesticide intensive agricultural landscape show signs of impaired olfaction

    NASA Astrophysics Data System (ADS)

    Chakrabarti, Priyadarshini; Rana, Santanu; Bandopadhyay, Sreejata; Naik, Dattatraya G.; Sarkar, Sagartirtha; Basu, Parthiba

    2015-07-01

    Little information is available regarding the adverse effects of pesticides on natural honey bee populations. This study highlights the detrimental effects of pesticides on honey bee olfaction through behavioural studies, scanning electron microscopic imaging of antennal sensillae and confocal microscopic studies of honey bee brains for calcium ions on Apis cerana, a native Indian honey bee species. There was a significant decrease in proboscis extension response and biologically active free calcium ions and adverse changes in antennal sensillae in pesticide exposed field honey bee populations compared to morphometrically similar honey bees sampled from low/no pesticide sites. Controlled laboratory experiments corroborated these findings. This study reports for the first time the changes in antennal sensillae, expression of Calpain 1(an important calcium binding protein) and resting state free calcium in brains of honey bees exposed to pesticide stress.

  1. Field populations of native Indian honey bees from pesticide intensive agricultural landscape show signs of impaired olfaction.

    PubMed

    Chakrabarti, Priyadarshini; Rana, Santanu; Bandopadhyay, Sreejata; Naik, Dattatraya G; Sarkar, Sagartirtha; Basu, Parthiba

    2015-01-01

    Little information is available regarding the adverse effects of pesticides on natural honey bee populations. This study highlights the detrimental effects of pesticides on honey bee olfaction through behavioural studies, scanning electron microscopic imaging of antennal sensillae and confocal microscopic studies of honey bee brains for calcium ions on Apis cerana, a native Indian honey bee species. There was a significant decrease in proboscis extension response and biologically active free calcium ions and adverse changes in antennal sensillae in pesticide exposed field honey bee populations compared to morphometrically similar honey bees sampled from low/no pesticide sites. Controlled laboratory experiments corroborated these findings. This study reports for the first time the changes in antennal sensillae, expression of Calpain 1(an important calcium binding protein) and resting state free calcium in brains of honey bees exposed to pesticide stress. PMID:26212690

  2. Field populations of native Indian honey bees from pesticide intensive agricultural landscape show signs of impaired olfaction

    PubMed Central

    Chakrabarti, Priyadarshini; Rana, Santanu; Bandopadhyay, Sreejata; Naik, Dattatraya G.; Sarkar, Sagartirtha; Basu, Parthiba

    2015-01-01

    Little information is available regarding the adverse effects of pesticides on natural honey bee populations. This study highlights the detrimental effects of pesticides on honey bee olfaction through behavioural studies, scanning electron microscopic imaging of antennal sensillae and confocal microscopic studies of honey bee brains for calcium ions on Apis cerana, a native Indian honey bee species. There was a significant decrease in proboscis extension response and biologically active free calcium ions and adverse changes in antennal sensillae in pesticide exposed field honey bee populations compared to morphometrically similar honey bees sampled from low/no pesticide sites. Controlled laboratory experiments corroborated these findings. This study reports for the first time the changes in antennal sensillae, expression of Calpain 1(an important calcium binding protein) and resting state free calcium in brains of honey bees exposed to pesticide stress. PMID:26212690

  3. Host adaptations reduce the reproductive success of Varroa destructor in two distinct European honey bee populations

    PubMed Central

    Locke, Barbara; Conte, Yves Le; Crauser, Didier; Fries, Ingemar

    2012-01-01

    Honey bee societies (Apis mellifera), the ectoparasitic mite Varroa destructor, and honey bee viruses that are vectored by the mite, form a complex system of host–parasite interactions. Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process. An increasing mite population means increasing transmission opportunities for viruses that can quickly develop into severe infections, killing a bee colony. Remarkably, a few subpopulations in Europe have survived mite infestation for extended periods of over 10 years without management by beekeepers and offer the possibility to study their natural host–parasite coevolution. Our study shows that two of these “natural” honey bee populations, in Avignon, France and Gotland, Sweden, have in fact evolved resistant traits that reduce the fitness of the mite (measured as the reproductive success), thereby reducing the parasitic load within the colony to evade the development of overt viral infections. Mite reproductive success was reduced by about 30% in both populations. Detailed examinations of mite reproductive parameters suggest these geographically and genetically distinct populations favor different mechanisms of resistance, even though they have experienced similar selection pressures of mite infestation. Compared to unrelated control colonies in the same location, mites in the Avignon population had high levels of infertility while in Gotland there was a higher proportions of mites that delayed initiation of egg-laying. Possible explanations for the observed rapid coevolution are discussed. PMID:22833790

  4. Intraspecific geographic variation of fragrances acquired by orchid bees in native and introduced populations.

    PubMed

    Ramírez, Santiago R; Eltz, Thomas; Fritzsch, Falko; Pemberton, Robert; Pringle, Elizabeth G; Tsutsui, Neil D

    2010-08-01

    Male orchid bees collect volatiles, from both floral and non-floral sources, that they expose as pheromone analogues (perfumes) during courtship display. The chemical profile of these perfumes, which includes terpenes and aromatic compounds, is both species-specific and divergent among closely related lineages. Thus, fragrance composition is thought to play an important role in prezygotic reproductive isolation in euglossine bees. However, because orchid bees acquire fragrances entirely from exogenous sources, the chemical composition of male perfumes is prone to variation due to environmental heterogeneity across habitats. We used Gas Chromatography/Mass Spectrometry (GC/MS) to characterize the perfumes of 114 individuals of the green orchid bee (Euglossa aff. viridissima) sampled from five native populations in Mesoamerica and two naturalized populations in the southeastern United States. We recorded a total of 292 fragrance compounds from hind-leg extracts, and found that overall perfume composition was different for each population. We detected a pronounced chemical dissimilarity between native (Mesoamerica) and naturalized (U.S.) populations that was driven both by proportional differences of common compounds as well as the presence of a few chemicals unique to each population group. Despite these differences, our data also revealed remarkable qualitative consistency in the presence of several major fragrance compounds across distant populations from dissimilar habitats. In addition, we demonstrate that naturalized bees are attracted to and collect large quantities of triclopyr 2-butoxyethyl ester, the active ingredient of several commercially available herbicides. By comparing incidence values and consistency indices across populations, we identify putative functional compounds that may play an important role in courtship signaling in this species of orchid bee.

  5. Prevalence and Seasonal Variations of Six Bee Viruses in Apis mellifera L. and Varroa destructor Mite Populations in France

    PubMed Central

    Tentcheva, Diana; Gauthier, Laurent; Zappulla, Nathalie; Dainat, Benjamin; Cousserans, François; Colin, Marc Edouard; Bergoin, Max

    2004-01-01

    A survey of six bee viruses on a large geographic scale was undertaken by using seemingly healthy bee colonies and the PCR technique. Samples of adult bees and pupae were collected from 36 apiaries in the spring, summer, and autumn during 2002. Varroa destructor samples were collected at the end of summer following acaricide treatment. In adult bees, during the year deformed wing virus (DWV) was found at least once in 97% of the apiaries, sacbrood virus (SBV) was found in 86% of the apiaries, chronic bee paralysis virus (CBPV) was found in 28% of the apiaries, acute bee paralysis virus (ABPV) was found in 58% of the apiaries, black queen cell virus (BQCV) was found in 86% of the apiaries, and Kashmir bee virus (KBV) was found in 17% of the apiaries. For pupae, the following frequencies were obtained: DWV, 94% of the apiaries; SBV, 80% of the apiaries; CBPV, none of the apiaries; ABPV, 23% of the apiaries; BQCV, 23% of the apiaries; and KBV, 6% of the apiaries. In Varroa samples, the following four viruses were identified: DWV (100% of the apiaries), SBV (45% of the apiaries), ABPV (36% of the apiaries), and KBV (5% of the apiaries). The latter findings support the putative role of mites in transmitting these viruses. Taken together, these data indicate that bee virus infections occur persistently in bee populations despite the lack of clinical signs, suggesting that colony disease outbreaks might result from environmental factors that lead to activation of viral replication in bees. PMID:15574916

  6. [Genetic Differentiation of Local Populations of the Dark European Bee Apis mellifera mellifera L. in the Urals].

    PubMed

    Il'yasov, R A; Poskryakov, A V; Petukhov, A V; Nikolenko, A G

    2015-07-01

    For the last two centuries, beekeepers in Russia and Europe have been introducing bees from the southern regions to the northern ones, subjecting the genetic pool of the dark European bee Apis mellifera mellifera L. subspecies to extensive hybridization. In order to reconfirm on the genetic level the previously published morphological data on the native bee population in the Urals, the Bashkortostan Republic, and the Perm Krai, we analyzed the polymorphism of the mitochondrial (mtDNA COI-COII intergenic locus) and nuclear (two microsatellite loci, ap243 and 4a110) DNA markers. Four local populations of the dark European bee A. m. mellifera surviving in the Urals have been identified, and their principal genetic characteristics have been determined. Data on the genetic structure and geographical localization of the areals of the dark European bee local populations in the Urals may be of use in restoring the damaged genetic pool of A. m. mellifera in Russia and other northern countries.

  7. Population growth of Varroa destructor (Acari: Varroidae) in commercial honey bee colonies treated with beta plant acids.

    PubMed

    DeGrandi-Hoffman, Gloria; Ahumada, Fabiana; Curry, Robert; Probasco, Gene; Schantz, Lloyd

    2014-10-01

    Varroa (Varroa destuctor Anderson and Trueman) populations in honey bee (Apis mellifera L.) colonies might be kept at low levels by well-timed miticide applications. HopGuard(®) (HG) that contains beta plant acids as the active ingredient was used to reduce mite populations. Schedules for applications of the miticide that could maintain low mite levels were tested in hives started from either package bees or splits of larger colonies. The schedules were developed based on defined parameters for efficacy of the miticide and predictions of varroa population growth generated from a mathematical model of honey bee colony-varroa population dynamics. Colonies started from package bees and treated with HG in the package only or with subsequent HG treatments in the summer had 1.2-2.1 mites per 100 bees in August. Untreated controls averaged significantly more mites than treated colonies (3.3 mites per 100 bees). By October, mite populations ranged from 6.3 to 15.0 mites per 100 bees with the lowest mite numbers in colonies treated with HG in August. HG applications in colonies started from splits in April reduced mite populations to 0.12 mites per 100 bees. In September, the treated colonies had significantly fewer mites than the untreated controls. Subsequent HG applications in September that lasted for 3 weeks reduced mite populations to levels in November that were significantly lower than in colonies that were untreated or had an HG treatment that lasted for 1 week. The model accurately predicted colony population growth and varroa levels until the fall when varroa populations measured in colonies established from package bees or splits were much greater than predicted. Possible explanations for the differences between actual and predicted mite populations are discussed.

  8. Rapid morphological changes in populations of hybrids between Africanized and European honey bees.

    PubMed

    Francoy, T M; Gonçalves, L S; De Jong, D

    2012-09-17

    African honey bees, introduced to Brazil in 1956, rapidly dominated the previously introduced European subspecies. To better understand how hybridization between these different types of bees proceeded, we made geometric morphometric analyses of the wing venation patterns of specimens resulting from crosses made between Africanized honey bees (predominantly Apis mellifera scutellata) and Italian honey bees (A. mellifera ligustica) from 1965 to 1967, at the beginning of the Africanization process, in an apiary about 150 km from the original introduction site. Two virgin queens reared from an Italian parental were instrumentally inseminated with semen from drones from an Africanized parental. Six F(1) queens from one of these colonies were open mated with Africanized drones. Resultant F(1) drones were backcrossed to 50 Italian and 50 Africanized parental queens. Five backcross workers were collected from each of eight randomly selected colonies of each type of backcross (N = 5 bees x 8 colonies x 2 types of backcrosses). The F1 progeny (40 workers and 30 drones) was found to be morphologically closer to the Africanized than to the European parental (N = 20 drones and 40 workers, each); Mahalanobis square distances = 21.6 versus 25.8, respectively, for the workers, and 39.9 versus 46.4, respectively, for the drones. The worker progenies of the backcrosses (N = 40, each) were placed between the respective parental and the F(1) progeny, although closer to the Africanized than to the Italian parentals (Mahalanobis square distance = 6.2 versus 12.1, respectively). Consequently, the most common crosses at the beginning of the Africanization process would have generated individuals more similar to Africanized than to Italian bees. This adds a genetic explanation for the rapid changes in the populational morphometric profile in recently colonized areas. Africanized alleles of wing venation pattern genes are apparently dominant and epistatic.

  9. Evaluation of the distribution and impacts of parasites, pathogens, and pesticides on honey bee (Apis mellifera) populations in East Africa.

    PubMed

    Muli, Elliud; Patch, Harland; Frazier, Maryann; Frazier, James; Torto, Baldwyn; Baumgarten, Tracey; Kilonzo, Joseph; Kimani, James Ng'ang'a; Mumoki, Fiona; Masiga, Daniel; Tumlinson, James; Grozinger, Christina

    2014-01-01

    In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations.

  10. Evaluation of the distribution and impacts of parasites, pathogens, and pesticides on honey bee (Apis mellifera) populations in East Africa.

    PubMed

    Muli, Elliud; Patch, Harland; Frazier, Maryann; Frazier, James; Torto, Baldwyn; Baumgarten, Tracey; Kilonzo, Joseph; Kimani, James Ng'ang'a; Mumoki, Fiona; Masiga, Daniel; Tumlinson, James; Grozinger, Christina

    2014-01-01

    In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations. PMID:24740399

  11. Evaluation of the Distribution and Impacts of Parasites, Pathogens, and Pesticides on Honey Bee (Apis mellifera) Populations in East Africa

    PubMed Central

    Frazier, James; Torto, Baldwyn; Baumgarten, Tracey; Kilonzo, Joseph; Kimani, James Ng'ang'a; Mumoki, Fiona; Masiga, Daniel; Tumlinson, James; Grozinger, Christina

    2014-01-01

    In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations. PMID:24740399

  12. Simulating a base population in honey bee for molecular genetic studies

    PubMed Central

    2012-01-01

    Background Over the past years, reports have indicated that honey bee populations are declining and that infestation by an ecto-parasitic mite (Varroa destructor) is one of the main causes. Selective breeding of resistant bees can help to prevent losses due to the parasite, but it requires that a robust breeding program and genetic evaluation are implemented. Genomic selection has emerged as an important tool in animal breeding programs and simulation studies have shown that it yields more accurate breeding value estimates, higher genetic gain and low rates of inbreeding. Since genomic selection relies on marker data, simulations conducted on a genomic dataset are a pre-requisite before selection can be implemented. Although genomic datasets have been simulated in other species undergoing genetic evaluation, simulation of a genomic dataset specific to the honey bee is required since this species has a distinct genetic and reproductive biology. Our software program was aimed at constructing a base population by simulating a random mating honey bee population. A forward-time population simulation approach was applied since it allows modeling of genetic characteristics and reproductive behavior specific to the honey bee. Results Our software program yielded a genomic dataset for a base population in linkage disequilibrium. In addition, information was obtained on (1) the position of markers on each chromosome, (2) allele frequency, (3) χ2 statistics for Hardy-Weinberg equilibrium, (4) a sorted list of markers with a minor allele frequency less than or equal to the input value, (5) average r2 values of linkage disequilibrium between all simulated marker loci pair for all generations and (6) average r2 value of linkage disequilibrium in the last generation for selected markers with the highest minor allele frequency. Conclusion We developed a software program that takes into account the genetic and reproductive biology specific to the honey bee and that can be used to

  13. Genetic variability in captive populations of the stingless bee Tetragonisca angustula.

    PubMed

    Santiago, Leandro R; Francisco, Flávio O; Jaffé, Rodolfo; Arias, Maria C

    2016-08-01

    Low genetic variability has normally been considered a consequence of animal husbandry and a major contributing factor to declining bee populations. Here, we performed a molecular analysis of captive and wild populations of the stingless bee Tetragonisca angustula, one of the most commonly kept species across South America. Microsatellite analyses showed similar genetic variability between wild and captive populations However, captive populations showed lower mitochondrial genetic variability. Male-mediated gene flow, transport and division of nests are suggested as the most probable explanations for the observed patterns of genetic structure. We conclude that increasing the number of colonies kept through nest divisions does not negatively affect nuclear genetic variability, which seems to be maintained by small-scale male dispersal and human-mediated nest transport. However, the transport of nests from distant localities should be practiced with caution given the high genetic differentiation observed between samples from western and eastern areas. The high genetic structure verified is the result of a long-term evolutionary process, and bees from distant localities may represent unique evolutionary lineages.

  14. Alfalfa leafcutting bee population dynamics, flower availability, and pollination rates in two Oregon alfalfa fields.

    PubMed

    Bosch, Jordi; Kemp, William P

    2005-08-01

    Since the 1970s, it has become increasingly difficult for U.S. alfalfa seed producers to maintain Megachile rotundata (F.) populations used for alfalfa, Medicago sativa L., pollination. In 1998, we monitored M. rotundata population dynamics and foraging behavior, as well as alfalfa bloom and pollination rates in two fields in eastern Oregon. Despite marked differences in bee management, establishment was very similar in the two fields (approximately 0.5 females per nesting cavity) and lagged peak bloom by approximately 2 wk. Pollination rates increased from 0-10% in the first 3 wk to 80-90% in week 4-5. By then, M. rotundata females had difficulty finding untripped (nonpollinated) flowers and visited large numbers of already tripped or not fully matured flowers. M. rotundata progeny mortality was very high (54-78%). Estimated seed yields were similar in both fields. We contend similar seed yields, and improved bee production, could be accomplished with smaller bee populations, better timed with alfalfa bloom. PMID:16156556

  15. The role of vibrations in population divergence in the red mason bee, Osmia bicornis.

    PubMed

    Conrad, Taina; Ayasse, Manfred

    2015-11-01

    Differences in female preference for certain male characteristics can be a driving force for population divergence and speciation [1-4]. During precopulation, females of the red mason bee, Osmia bicornis, choose suitable males based on, among other criteria, their thoracic vibrations [5]. These vibrations are thought to be a signal of a male's fitness with females choosing the strongest males that can vibrate for the longest time [5]. The precise role of such vibrational signals, however, has not been determined by bioassays, and the vibrations might also play a role in species recognition [6]. There are two main subspecies of O. bicornis in Europe distinguishable only by a single morphological trait [7] (Figure S1). We therefore developed a new bioassay allowing us to impose the vibrations of one live male onto another in order to discern possible selective mate choice by females from O. bicornis originating from different regions of Europe. Females showed strong preference for males from their own region, and male vibrations were the main signal involved in this choice. Thus, vibrational signals encode not only fitness but also information about the region of origin indicating that divergence exists between the different European O. bicornis populations, which might ultimately lead to speciation. These results provide new insights into the scope of vibrational communication in bees, a group previously considered to rely predominantly on chemical signals [8, 9]. Our newly developed method should shed further light on many exciting questions concerning vibrational communication in bees and other animal taxa.

  16. The role of vibrations in population divergence in the red mason bee, Osmia bicornis.

    PubMed

    Conrad, Taina; Ayasse, Manfred

    2015-11-01

    Differences in female preference for certain male characteristics can be a driving force for population divergence and speciation [1-4]. During precopulation, females of the red mason bee, Osmia bicornis, choose suitable males based on, among other criteria, their thoracic vibrations [5]. These vibrations are thought to be a signal of a male's fitness with females choosing the strongest males that can vibrate for the longest time [5]. The precise role of such vibrational signals, however, has not been determined by bioassays, and the vibrations might also play a role in species recognition [6]. There are two main subspecies of O. bicornis in Europe distinguishable only by a single morphological trait [7] (Figure S1). We therefore developed a new bioassay allowing us to impose the vibrations of one live male onto another in order to discern possible selective mate choice by females from O. bicornis originating from different regions of Europe. Females showed strong preference for males from their own region, and male vibrations were the main signal involved in this choice. Thus, vibrational signals encode not only fitness but also information about the region of origin indicating that divergence exists between the different European O. bicornis populations, which might ultimately lead to speciation. These results provide new insights into the scope of vibrational communication in bees, a group previously considered to rely predominantly on chemical signals [8, 9]. Our newly developed method should shed further light on many exciting questions concerning vibrational communication in bees and other animal taxa. PMID:26592342

  17. The impact of host starvation on parasite development and population dynamics in an intestinal trypanosome parasite of bumble bees.

    PubMed

    Logan, A; Ruiz-González, M X; Brown, M J F

    2005-06-01

    Host nutrition plays an important role in determining the development and success of parasitic infections. While studies of vertebrate hosts are accumulating, little is known about how host nutrition affects parasites of invertebrate hosts. Crithidia bombi is a gut trypanosome parasite of the bumble bee, Bombus terrestris and here we use it as a model system to determine the impact of host nutrition on the population dynamics and development of micro-parasites in invertebrates. Pollen-starved bees supported significantly smaller populations of the parasite. In pollen-fed bees the parasite showed a temporal pattern in development, with promastigote transmission stages appearing at the start of the infection and gradually being replaced by choanomastigote and amastigote forms. In pollen-starved bees this developmental process was disrupted, and there was no pattern in the appearance of these three forms. We discuss the implications of these results for parasite transmission, and speculate about the mechanisms behind these changes.

  18. A historical review of managed honey bee populations in Europe and the United States and the factors that may affect them.

    PubMed

    Vanengelsdorp, Dennis; Meixner, Marina Doris

    2010-01-01

    Honey bees are a highly valued resource around the world. They are prized for their honey and wax production and depended upon for pollination of many important crops. While globally honey bee populations have been increasing, the rate of increase is not keeping pace with demand. Further, honey bee populations have not been increasing in all parts of the world, and have declined in many nations in Europe and in North America. Managed honey bee populations are influenced by many factors including diseases, parasites, pesticides, the environment, and socio-economic factors. These factors can act alone or in combination with each other. This review highlights the present day value of honey bees, followed by a detailed description of some of the historical and present day factors that influence honey bee populations, with particular emphasis on colony populations in Europe and the United States. PMID:19909973

  19. Molecular genetic diversity in populations of the stingless bee Plebeia remota: A case study

    PubMed Central

    de Oliveira Francisco, Flávio; Santiago, Leandro Rodrigues; Arias, Maria Cristina

    2013-01-01

    Genetic diversity is a major component of the biological diversity of an ecosystem. The survival of a population may be seriously threatened if its genetic diversity values are low. In this work, we measured the genetic diversity of the stingless bee Plebeia remota based on molecular data obtained by analyzing 15 microsatellite loci and sequencing two mitochondrial genes. Population structure and genetic diversity differed depending on the molecular marker analyzed: microsatellites showed low population structure and moderate to high genetic diversity, while mitochondrial DNA (mtDNA) showed high population structure and low diversity in three populations. Queen philopatry and male dispersal behavior are discussed as the main reasons for these findings. PMID:23569417

  20. Molecular genetic diversity in populations of the stingless bee Plebeia remota: A case study.

    PubMed

    de Oliveira Francisco, Flávio; Santiago, Leandro Rodrigues; Arias, Maria Cristina

    2013-03-01

    Genetic diversity is a major component of the biological diversity of an ecosystem. The survival of a population may be seriously threatened if its genetic diversity values are low. In this work, we measured the genetic diversity of the stingless bee Plebeia remota based on molecular data obtained by analyzing 15 microsatellite loci and sequencing two mitochondrial genes. Population structure and genetic diversity differed depending on the molecular marker analyzed: microsatellites showed low population structure and moderate to high genetic diversity, while mitochondrial DNA (mtDNA) showed high population structure and low diversity in three populations. Queen philopatry and male dispersal behavior are discussed as the main reasons for these findings. PMID:23569417

  1. Population growth of Varroa destructor (Acari: Varroidae) in honey bee colonies is affected by the number of foragers with mites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Varroa mites are a serious pest of honey bees and the leading cause of colony losses. Varroa have relatively low reproductive rates, so populations should not increase rapidly, but often they do. Other factors might contribute to the growth of Varroa populations including mite migration into colonie...

  2. The effects of dietary protein levels on the population growth, performance, and physiology of honey bee workers during early spring.

    PubMed

    Zheng, Benle; Wu, Zaifu; Xu, Baohua

    2014-01-01

    This study was conducted to investigate the effects of dietary protein levels on honey bee colonies, specifically the population growth, physiology, and longevity of honey bee workers during early spring. Diets containing four different levels of crude protein (25.0, 29.5, 34.0, or 38.5%) and pure pollen (control) were evaluated. Twenty-five colonies of honey bees with sister queens were used in the study. We compared the effects of the different bee diets by measuring population growth, emergent worker weight, midgut proteolytic enzyme activity, hypopharyngeal gland development, and survival. After 48 d, the cumulative number of workers produced by the colonies ranged from 22,420 to 29,519, providing a significant fit to a quadratic equation that predicts the maximum population growth when the diet contains 31.7% crude protein. Significantly greater emergent worker weight, midgut proteolytic enzyme activity, hypopharyngeal gland acini, and survival were observed in the colonies that were fed diets containing 34.0% crude protein compared with the other crude protein levels. Although higher emergent worker weight and survival were observed in the colonies that were fed the control diet, there were no significant differences between the control colonies and the colonies that were fed 34.0% crude protein. Based on these results, we concluded that a dietary crude protein content of 29.5-34.0% is recommended to maximize the reproduction rate of honey bee colonies in early spring.

  3. [Genetic Differentiation of Local Populations of the Dark European Bee Apis mellifera mellifera L. in the Urals].

    PubMed

    Il'yasov, R A; Poskryakov, A V; Petukhov, A V; Nikolenko, A G

    2015-07-01

    For the last two centuries, beekeepers in Russia and Europe have been introducing bees from the southern regions to the northern ones, subjecting the genetic pool of the dark European bee Apis mellifera mellifera L. subspecies to extensive hybridization. In order to reconfirm on the genetic level the previously published morphological data on the native bee population in the Urals, the Bashkortostan Republic, and the Perm Krai, we analyzed the polymorphism of the mitochondrial (mtDNA COI-COII intergenic locus) and nuclear (two microsatellite loci, ap243 and 4a110) DNA markers. Four local populations of the dark European bee A. m. mellifera surviving in the Urals have been identified, and their principal genetic characteristics have been determined. Data on the genetic structure and geographical localization of the areals of the dark European bee local populations in the Urals may be of use in restoring the damaged genetic pool of A. m. mellifera in Russia and other northern countries. PMID:26410933

  4. The effects of dietary protein levels on the population growth, performance, and physiology of honey bee workers during early spring.

    PubMed

    Zheng, Benle; Wu, Zaifu; Xu, Baohua

    2014-01-01

    This study was conducted to investigate the effects of dietary protein levels on honey bee colonies, specifically the population growth, physiology, and longevity of honey bee workers during early spring. Diets containing four different levels of crude protein (25.0, 29.5, 34.0, or 38.5%) and pure pollen (control) were evaluated. Twenty-five colonies of honey bees with sister queens were used in the study. We compared the effects of the different bee diets by measuring population growth, emergent worker weight, midgut proteolytic enzyme activity, hypopharyngeal gland development, and survival. After 48 d, the cumulative number of workers produced by the colonies ranged from 22,420 to 29,519, providing a significant fit to a quadratic equation that predicts the maximum population growth when the diet contains 31.7% crude protein. Significantly greater emergent worker weight, midgut proteolytic enzyme activity, hypopharyngeal gland acini, and survival were observed in the colonies that were fed diets containing 34.0% crude protein compared with the other crude protein levels. Although higher emergent worker weight and survival were observed in the colonies that were fed the control diet, there were no significant differences between the control colonies and the colonies that were fed 34.0% crude protein. Based on these results, we concluded that a dietary crude protein content of 29.5-34.0% is recommended to maximize the reproduction rate of honey bee colonies in early spring. PMID:25368092

  5. Male reproductive parasitism: a factor in the africanization of European honey-bee populations.

    PubMed

    Rinderer, T E; Hellmich, R L; Danka, R G; Collins, A M

    1985-05-31

    Africanized drone honey bees (Apis mellifera) migrate into European honey-bee colonies in large numbers, but Africanized colonies only rarely host drones from other colonies. This migration leads to a strong mating advantage for Africanized bees since it both inhibits European drone production and enhances Africanized drone production.

  6. Comparisons of Pollen Substitute Diets for Honey bees: Consumprion Rates by Colonies and Effects on Brood and Adult Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercially available pollen substitute diets for honey bees (Apis mellifera L.) were evaluated for consumption and colony growth (brood and adult populations) and compared with pollen cake and high fructose corn syrup (HFCS). Two trials were conducted; the first for 4 months during the fall and wi...

  7. Comparisons of pollen substitute diets for honey bees: consumption rates by colonies and effects on brood and adult populations.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercially available pollen substitute diets for honey bees (Apis mellifera L.) were evaluated for consumption and colony growth (brood and adult populations) and compared with pollen cake and high fructose corn syrup (HFCS). Two trials were conducted; the first for 3 months during the fall and w...

  8. Floral preferences of a neotropical stingless bee, Melipona quadrifasciata Lepeletier (Apidae: Meliponina) in an urban forest fragment.

    PubMed

    Antonini, Y; Costa, R G; Martins, R P

    2006-05-01

    Species of plants used by Melipona quadrifasciata Lepeletier for pollen and nectar gathering in an urban forest fragment were recorded in Belo Horizonte, Minas Gerais, Brazil. Melipona quadrifasciata visited 22 out of 103 flowering plant species. The plant species belonged mainly to Myrtaceae, Asteraceae, and Convolvulaceae (64% of the visits). Melipona quadrifasciata tended to collect pollen or nectar each time, except for Myrtaceae species, from which both pollen and nectar were collected. Bee abundance at flowers did not significantly correlate to food availability (expressed by flowering plant richness). We found a relatively high similarity (50%) between plant species used by M. quadrifasciata, which was also found in studies carried out in São Paulo State. However, low similarity (17%) was found between the results of this study and those of another done in Bahia State, Brazil.

  9. Population trends of forest birds at Hakalau Forest National Wildlife Refuge, Hawai'i

    USGS Publications Warehouse

    Camp, Richard J.; Pratt, Thane K.; Gorresen, P. Marcos; Jeffrey, John J.; Woodworth, Bethany L.

    2010-01-01

    The Hakalau Forest National Wildlife Refuge was established to protect native Hawaiian forest birds, particularly endangered species. Management for forest restoration on the refuge has consisted mainly of removing feral ungulates, controlling invasive alien plants, and reforesting former pastures. To assess effects of this habitat improvement for forest birds, we estimated density annually by distance sampling and examined population trends for native and alien passerines over the 21 years since the refuge was established. We examined long-term trends and recent short-term trajectories in three study areas: (1) reforested pastureland, (2) heavily grazed open forest that was recovering, and (3) lightly grazed closed forest that was relatively intact. Three species of native birds and two species of alien birds had colonized the reforested pasture and were increasing. In the open forest, densities of all eight native species were either stable or increasing. Long-term trends for alien birds were also generally stable or increasing. Worryingly, however, during the most recent 9 years, in the open forest trajectories of native species were decreasing or inconclusive, but in the reforested pasture they generally increased. The closed forest was surveyed in only the most recent 9 years, and trajectories of native species there were mixed. Overall, long-term population trends in Hakalau are stable or increasing, contrasting with declines in most other areas of Hawai'i over the same period. However, more recent mixed results may indicate emergent problems for this important bird area.

  10. Nest suitability, fine-scale population structure and male-mediated dispersal of a solitary ground nesting bee in an urban landscape.

    PubMed

    López-Uribe, Margarita M; Morreale, Stephen J; Santiago, Christine K; Danforth, Bryan N

    2015-01-01

    Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei's GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing

  11. Nest suitability, fine-scale population structure and male-mediated dispersal of a solitary ground nesting bee in an urban landscape.

    PubMed

    López-Uribe, Margarita M; Morreale, Stephen J; Santiago, Christine K; Danforth, Bryan N

    2015-01-01

    Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei's GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing

  12. Nest Suitability, Fine-Scale Population Structure and Male-Mediated Dispersal of a Solitary Ground Nesting Bee in an Urban Landscape

    PubMed Central

    López-Uribe, Margarita M.; Morreale, Stephen J.; Santiago, Christine K.; Danforth, Bryan N.

    2015-01-01

    Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei’s GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for

  13. Population growth of Varroa destructor (Acari: Varroidae) in honey bee colonies is affected by the number of foragers with mites.

    PubMed

    DeGrandi-Hoffman, Gloria; Ahumada, Fabiana; Zazueta, Victor; Chambers, Mona; Hidalgo, Geoffrey; deJong, Emily Watkins

    2016-05-01

    Varroa mites are a serious pest of honey bees and the leading cause of colony losses. Varroa have relatively low reproductive rates, so populations should not increase rapidly, but often they do. Other factors might contribute to the growth of varroa populations including mite migration into colonies on foragers from other hives. We measured the proportion of foragers carrying mites on their bodies while entering and leaving hives, and determined its relationship to the growth of varroa populations in those hives at two apiary sites. We also compared the estimates of mite population growth with predictions from a varroa population dynamics model that generates estimates of mite population growth based on mite reproduction. Samples of capped brood and adult bees indicated that the proportion of brood cells infested with mites and adult bees with phoretic mites was low through the summer but increased sharply in the fall especially at site 1. The frequency of capturing foragers with mites on their bodies while entering or leaving hives also increased in the fall. The growth of varroa populations at both sites was not significantly related to our colony estimates of successful mite reproduction, but instead to the total number of foragers with mites (entering and leaving the colony). There were more foragers with mites at site 1 than site 2, and mite populations at site 1 were larger especially in the fall. The model accurately estimated phoretic mite populations and infested brood cells until November when predictions were much lower than those measured in colonies. The rapid growth of mite populations particularly in the fall being a product of mite migration rather than mite reproduction only is discussed.

  14. Population growth of Varroa destructor (Acari: Varroidae) in honey bee colonies is affected by the number of foragers with mites.

    PubMed

    DeGrandi-Hoffman, Gloria; Ahumada, Fabiana; Zazueta, Victor; Chambers, Mona; Hidalgo, Geoffrey; deJong, Emily Watkins

    2016-05-01

    Varroa mites are a serious pest of honey bees and the leading cause of colony losses. Varroa have relatively low reproductive rates, so populations should not increase rapidly, but often they do. Other factors might contribute to the growth of varroa populations including mite migration into colonies on foragers from other hives. We measured the proportion of foragers carrying mites on their bodies while entering and leaving hives, and determined its relationship to the growth of varroa populations in those hives at two apiary sites. We also compared the estimates of mite population growth with predictions from a varroa population dynamics model that generates estimates of mite population growth based on mite reproduction. Samples of capped brood and adult bees indicated that the proportion of brood cells infested with mites and adult bees with phoretic mites was low through the summer but increased sharply in the fall especially at site 1. The frequency of capturing foragers with mites on their bodies while entering or leaving hives also increased in the fall. The growth of varroa populations at both sites was not significantly related to our colony estimates of successful mite reproduction, but instead to the total number of foragers with mites (entering and leaving the colony). There were more foragers with mites at site 1 than site 2, and mite populations at site 1 were larger especially in the fall. The model accurately estimated phoretic mite populations and infested brood cells until November when predictions were much lower than those measured in colonies. The rapid growth of mite populations particularly in the fall being a product of mite migration rather than mite reproduction only is discussed. PMID:26910522

  15. Forest management under uncertainty for multiple bird population objectives

    USGS Publications Warehouse

    Moore, C.T.; Plummer, W.T.; Conroy, M.J.; Ralph, C. John; Rich, Terrell D.

    2005-01-01

    We advocate adaptive programs of decision making and monitoring for the management of forest birds when responses by populations to management, and particularly management trade-offs among populations, are uncertain. Models are necessary components of adaptive management. Under this approach, uncertainty about the behavior of a managed system is explicitly captured in a set of alternative models. The models generate testable predictions about the response of populations to management, and monitoring data provide the basis for assessing these predictions and informing future management decisions. To illustrate these principles, we examine forest management at the Piedmont National Wildlife Refuge, where management attention is focused on the recovery of the Red-cockaded Woodpecker (Picoides borealis) population. However, managers are also sensitive to the habitat needs of many non-target organisms, including Wood Thrushes (Hylocichla mustelina) and other forest interior Neotropical migratory birds. By simulating several management policies on a set of-alternative forest and bird models, we found a decision policy that maximized a composite response by woodpeckers and Wood Thrushes despite our complete uncertainty regarding system behavior. Furthermore, we used monitoring data to update our measure of belief in each alternative model following one cycle of forest management. This reduction of uncertainty translates into a reallocation of model influence on the choice of optimal decision action at the next decision opportunity.

  16. Assessing Honey Bee (Hymenoptera: Apidae) Foraging Populations and the Potential Impact of Pesticides on Eight U.S. Crops.

    PubMed

    Frazier, Maryann T; Mullin, Chris A; Frazier, Jim L; Ashcraft, Sara A; Leslie, Tim W; Mussen, Eric C; Drummond, Frank A

    2015-10-01

    Beekeepers who use honey bees (Apis mellifera L.) for crop pollination services, or have colonies making honey on or in close proximity to agricultural crops, are concerned about the reductions of colony foragers and ultimate weakening of their colonies. Pesticide exposure is a potential factor in the loss of foragers. During 2009-2010, we assessed changes in the field force populations of 9-10 colonies at one location per crop on each of the eight crops by counting departing foragers leaving colonies at regular intervals during the respective crop blooming periods. The number of frames of adult bees was counted before and after bloom period. For pesticide analysis, we collected dead and dying bees near the hives, returning foragers, crop flowers, trapped pollen, and corn-flowers associated with the cotton crop. The number of departing foragers changed over time in all crops except almonds; general patterns in foraging activity included declines (cotton), noticeable peaks and declines (alfalfa, blueberries, cotton, corn, and pumpkins), and increases (apples and cantaloupes). The number of adult bee frames increased or remained stable in all crops except alfalfa and cotton. A total of 53 different pesticide residues were identified in samples collected across eight crops. Hazard quotients (HQ) were calculated for the combined residues for all crop-associated samples and separately for samples of dead and dying bees. A decrease in the number of departing foragers in cotton was one of the most substantial crop-associated impacts and presented the highest pesticide risk estimated by a summed pesticide residue HQ. PMID:26453703

  17. Effect of Lactobacillus johnsonii CRL1647 on different parameters of honeybee colonies and bacterial populations of the bee gut.

    PubMed

    Audisio, M C; Sabaté, D C; Benítez-Ahrendts, M R

    2015-01-01

    Lactobacillus johnsonii CRL1647, isolated from the intestinal tract of a worker-bee in Salta, Argentina, was delivered to Apis mellifera L. honey bee colonies according to two different administration schedules: 1×10(5) cfu/ml every 15 days (2011) or monthly (2012). The effect of each treatment on the bee-colony performance was monitored by measuring honey production, and the prevalence of varroasis and nosemosis. Worker bees from each assay were randomly captured 3 days after administration and assayed for the following intestinal culturable and defined bacterial populations: total aerobic microorganisms, Bacillus spp. spores, Lactobacillus spp., Enterococcus spp. and enterobacteria. Interestingly, both treatments generated a similar increase in honey production in treated colonies compared to controls: 36.8% (every 15 days) and 36.3% (monthly). Nosema index always exhibited a reduction when lactobacilli were administered; in turn, Varroa incidence was lower when the lactobacilli were administered once a month. Moreover, the administration of L. johnsonii CRL1647 every 15 days produced an increase in the total number of aerobic microorganisms and in bacteria belonging to the genera Lactobacillus and Enterococcus; at the same time, a decrease was observed in the number of total spores at the end of the treatment. The number of enterobacteria was constant and remained below that of control hives at the end of the assay. On the other hand, the delivery of lactobacilli once a month only showed an increase in the number of bacteria belonging to the genus Lactobacillus; meanwhile, viable counts of the remaining microorganisms assayed were reduced. Even though it seems that both treatments were similar, those bee colonies that received L. johnsonii CRL1647 every 15 days became so strong that they swarmed.

  18. Assessing Honey Bee (Hymenoptera: Apidae) Foraging Populations and the Potential Impact of Pesticides on Eight U.S. Crops.

    PubMed

    Frazier, Maryann T; Mullin, Chris A; Frazier, Jim L; Ashcraft, Sara A; Leslie, Tim W; Mussen, Eric C; Drummond, Frank A

    2015-10-01

    Beekeepers who use honey bees (Apis mellifera L.) for crop pollination services, or have colonies making honey on or in close proximity to agricultural crops, are concerned about the reductions of colony foragers and ultimate weakening of their colonies. Pesticide exposure is a potential factor in the loss of foragers. During 2009-2010, we assessed changes in the field force populations of 9-10 colonies at one location per crop on each of the eight crops by counting departing foragers leaving colonies at regular intervals during the respective crop blooming periods. The number of frames of adult bees was counted before and after bloom period. For pesticide analysis, we collected dead and dying bees near the hives, returning foragers, crop flowers, trapped pollen, and corn-flowers associated with the cotton crop. The number of departing foragers changed over time in all crops except almonds; general patterns in foraging activity included declines (cotton), noticeable peaks and declines (alfalfa, blueberries, cotton, corn, and pumpkins), and increases (apples and cantaloupes). The number of adult bee frames increased or remained stable in all crops except alfalfa and cotton. A total of 53 different pesticide residues were identified in samples collected across eight crops. Hazard quotients (HQ) were calculated for the combined residues for all crop-associated samples and separately for samples of dead and dying bees. A decrease in the number of departing foragers in cotton was one of the most substantial crop-associated impacts and presented the highest pesticide risk estimated by a summed pesticide residue HQ.

  19. Assessing Honey Bee (Hymenoptera: Apidae) Foraging Populations and the Potential Impact of Pesticides on Eight U.S. Crops

    PubMed Central

    Frazier, Maryann T.; Mullin, Chris A.; Frazier, Jim L.; Ashcraft, Sara A.; Leslie, Tim W.; Mussen, Eric C.; Drummond, Frank A.

    2015-01-01

    Beekeepers who use honey bees (Apis mellifera L.) for crop pollination services, or have colonies making honey on or in close proximity to agricultural crops, are concerned about the reductions of colony foragers and ultimate weakening of their colonies. Pesticide exposure is a potential factor in the loss of foragers. During 2009–2010, we assessed changes in the field force populations of 9–10 colonies at one location per crop on each of the eight crops by counting departing foragers leaving colonies at regular intervals during the respective crop blooming periods. The number of frames of adult bees was counted before and after bloom period. For pesticide analysis, we collected dead and dying bees near the hives, returning foragers, crop flowers, trapped pollen, and corn-flowers associated with the cotton crop. The number of departing foragers changed over time in all crops except almonds; general patterns in foraging activity included declines (cotton), noticeable peaks and declines (alfalfa, blueberries, cotton, corn, and pumpkins), and increases (apples and cantaloupes). The number of adult bee frames increased or remained stable in all crops except alfalfa and cotton. A total of 53 different pesticide residues were identified in samples collected across eight crops. Hazard quotients (HQ) were calculated for the combined residues for all crop-associated samples and separately for samples of dead and dying bees. A decrease in the number of departing foragers in cotton was one of the most substantial crop-associated impacts and presented the highest pesticide risk estimated by a summed pesticide residue HQ. PMID:26453703

  20. Distance Between Honey Bee Apis mellifera Colonies Regulates Populations of Varroa destructor at a Landscape Scale

    PubMed Central

    Nolan, Maxcy P.; Delaplane, Keith S.

    2016-01-01

    Inter-colony distance of Apis mellifera significantly affects colony numbers of the parasitic mite Varroa destructor. We set up 15 apiaries, each consisting of two colonies. Each apiary pair was assigned an inter-colony distance of 0, 10, or 100 m. Colonies were rendered nearly mite-free, then one colony in each pair was seeded with 300 female mites (mite-donor colony), while the other remained uninoculated (mite-recipient colony). After four months of monitoring, a whole model analysis showed that apiaries in which colonies were spaced 100 m apart contained lower average mite numbers than 0 m or 10 m apiaries. There were interactions among colony type, distance, and sampling date; however, when there were significant differences mite numbers were always lower in 100 m apiaries than 10 m apiaries. These findings pose the possibility that Varroa populations are resource regulated at a landscape scale: near-neighbor colonies constitute reproductive resource for mites in the form of additional bee brood. PMID:27812228

  1. Ocelot Population Status in Protected Brazilian Atlantic Forest.

    PubMed

    Massara, Rodrigo Lima; Paschoal, Ana Maria de Oliveira; Doherty, Paul Francis; Hirsch, André; Chiarello, Adriano Garcia

    2015-01-01

    Forest fragmentation and habitat loss are detrimental to top carnivores, such as jaguars (Panthera onca) and pumas (Puma concolor), but effects on mesocarnivores, such as ocelots (Leopardus pardalis), are less clear. Ocelots need native forests, but also might benefit from the local extirpation of larger cats such as pumas and jaguars through mesopredator release. We used a standardized camera trap protocol to assess ocelot populations in six protected areas of the Atlantic forest in southeastern Brazil where over 80% of forest remnants are < 50 ha. We tested whether variation in ocelot abundance could be explained by reserve size, forest cover, number of free-ranging domestic dogs and presence of top predators. Ocelot abundance was positively correlated with reserve size and the presence of top predators (jaguar and pumas) and negatively correlated with the number of dogs. We also found higher detection probabilities in less forested areas as compared to larger, intact forests. We suspect that smaller home ranges and higher movement rates in smaller, more degraded areas increased detection. Our data do not support the hypothesis of mesopredator release. Rather, our findings indicate that ocelots respond negatively to habitat loss, and thrive in large protected areas inhabited by top predators. PMID:26560347

  2. Ocelot Population Status in Protected Brazilian Atlantic Forest.

    PubMed

    Massara, Rodrigo Lima; Paschoal, Ana Maria de Oliveira; Doherty, Paul Francis; Hirsch, André; Chiarello, Adriano Garcia

    2015-01-01

    Forest fragmentation and habitat loss are detrimental to top carnivores, such as jaguars (Panthera onca) and pumas (Puma concolor), but effects on mesocarnivores, such as ocelots (Leopardus pardalis), are less clear. Ocelots need native forests, but also might benefit from the local extirpation of larger cats such as pumas and jaguars through mesopredator release. We used a standardized camera trap protocol to assess ocelot populations in six protected areas of the Atlantic forest in southeastern Brazil where over 80% of forest remnants are < 50 ha. We tested whether variation in ocelot abundance could be explained by reserve size, forest cover, number of free-ranging domestic dogs and presence of top predators. Ocelot abundance was positively correlated with reserve size and the presence of top predators (jaguar and pumas) and negatively correlated with the number of dogs. We also found higher detection probabilities in less forested areas as compared to larger, intact forests. We suspect that smaller home ranges and higher movement rates in smaller, more degraded areas increased detection. Our data do not support the hypothesis of mesopredator release. Rather, our findings indicate that ocelots respond negatively to habitat loss, and thrive in large protected areas inhabited by top predators.

  3. Ocelot Population Status in Protected Brazilian Atlantic Forest

    PubMed Central

    Massara, Rodrigo Lima; Paschoal, Ana Maria de Oliveira; Doherty, Paul Francis; Hirsch, André; Chiarello, Adriano Garcia

    2015-01-01

    Forest fragmentation and habitat loss are detrimental to top carnivores, such as jaguars (Panthera onca) and pumas (Puma concolor), but effects on mesocarnivores, such as ocelots (Leopardus pardalis), are less clear. Ocelots need native forests, but also might benefit from the local extirpation of larger cats such as pumas and jaguars through mesopredator release. We used a standardized camera trap protocol to assess ocelot populations in six protected areas of the Atlantic forest in southeastern Brazil where over 80% of forest remnants are < 50 ha. We tested whether variation in ocelot abundance could be explained by reserve size, forest cover, number of free-ranging domestic dogs and presence of top predators. Ocelot abundance was positively correlated with reserve size and the presence of top predators (jaguar and pumas) and negatively correlated with the number of dogs. We also found higher detection probabilities in less forested areas as compared to larger, intact forests. We suspect that smaller home ranges and higher movement rates in smaller, more degraded areas increased detection. Our data do not support the hypothesis of mesopredator release. Rather, our findings indicate that ocelots respond negatively to habitat loss, and thrive in large protected areas inhabited by top predators. PMID:26560347

  4. Africanization of a feral honey bee (Apis mellifera) population in South Texas: does a decade make a difference?

    PubMed

    Rangel, Juliana; Giresi, Melissa; Pinto, Maria Alice; Baum, Kristen A; Rubink, William L; Coulson, Robert N; Johnston, John Spencer

    2016-04-01

    The arrival to the United States of the Africanized honey bee, a hybrid between European subspecies and the African subspecies Apis mellifera scutellata, is a remarkable model for the study of biological invasions. This immigration has created an opportunity to study the dynamics of secondary contact of honey bee subspecies from African and European lineages in a feral population in South Texas. An 11-year survey of this population (1991-2001) showed that mitochondrial haplotype frequencies changed drastically over time from a resident population of eastern and western European maternal ancestry, to a population dominated by the African haplotype. A subsequent study of the nuclear genome showed that the Africanization process included bidirectional gene flow between European and Africanized honey bees, giving rise to a new panmictic mixture of A. m. scutellata- and European-derived genes. In this study, we examined gene flow patterns in the same population 23 years after the first hybridization event occurred. We found 28 active colonies inhabiting 92 tree cavities surveyed in a 5.14 km(2) area, resulting in a colony density of 5.4 colonies/km(2). Of these 28 colonies, 25 were of A. m. scutellata maternal ancestry, and three were of western European maternal ancestry. No colonies of eastern European maternal ancestry were detected, although they were present in the earlier samples. Nuclear DNA revealed little change in the introgression of A. m. scutellata-derived genes into the population compared to previous surveys. Our results suggest this feral population remains an admixed swarm with continued low levels of European ancestry and a greater presence of African-derived mitochondrial genetic composition.

  5. Africanization of a feral honey bee (Apis mellifera) population in South Texas: does a decade make a difference?

    PubMed

    Rangel, Juliana; Giresi, Melissa; Pinto, Maria Alice; Baum, Kristen A; Rubink, William L; Coulson, Robert N; Johnston, John Spencer

    2016-04-01

    The arrival to the United States of the Africanized honey bee, a hybrid between European subspecies and the African subspecies Apis mellifera scutellata, is a remarkable model for the study of biological invasions. This immigration has created an opportunity to study the dynamics of secondary contact of honey bee subspecies from African and European lineages in a feral population in South Texas. An 11-year survey of this population (1991-2001) showed that mitochondrial haplotype frequencies changed drastically over time from a resident population of eastern and western European maternal ancestry, to a population dominated by the African haplotype. A subsequent study of the nuclear genome showed that the Africanization process included bidirectional gene flow between European and Africanized honey bees, giving rise to a new panmictic mixture of A. m. scutellata- and European-derived genes. In this study, we examined gene flow patterns in the same population 23 years after the first hybridization event occurred. We found 28 active colonies inhabiting 92 tree cavities surveyed in a 5.14 km(2) area, resulting in a colony density of 5.4 colonies/km(2). Of these 28 colonies, 25 were of A. m. scutellata maternal ancestry, and three were of western European maternal ancestry. No colonies of eastern European maternal ancestry were detected, although they were present in the earlier samples. Nuclear DNA revealed little change in the introgression of A. m. scutellata-derived genes into the population compared to previous surveys. Our results suggest this feral population remains an admixed swarm with continued low levels of European ancestry and a greater presence of African-derived mitochondrial genetic composition. PMID:27069571

  6. Forest bird and fruit bat populations on Sarigan, Mariana Islands

    USGS Publications Warehouse

    Fancy, Steven G.; Craig, Robert J.; Kessler, Curt T.

    1999-01-01

    We conducted the first quantitative surveys of forest bird and bat populations on the uninhabited island of Sarigan, Commonwealth of the Northern Mariana Islands. Severe habitat degradation has occurred on Sarigan because of overgrazing by introduced goats and pigs. Planting of coconut palms (Cocos nucifera) for copra production has also eliminated much of the island’s native forest. We recorded five species of forest birds on Sarigan: Micronesian Honeyeater (Myzomela rubratra), Micronesian Megapode (Megapodius laperouse laperouse), Micronesian Starling (Aplonis opaca), Collared Kingfisher (Halcyon chloris), and White-throated Ground Dove (Gallicolumba xanthonura). Estimated population sizes (95% confidence interval) in 1997 were 1,821 (1,617–2,026) for Micronesian Honeyeater, 677 (545–810) for Micronesian Megapode, 497 (319–675) for Micronesian Starling, 107 (82–131) for Collared Kingfisher, and 170 (101–238) for Mariana Fruit Bat (Pteropus mariannus).

  7. The importance of odor in nest site selection by a lodger bee, Centris Bicornuta Mocsáry (Hymenoptera: Apidae) in the dry forest of Costa Rica.

    PubMed

    Vinson, S B; Frankie, G W; Rao, A

    2011-01-01

    The more common lodger bee occurring in the dry forest of Costa Rica, Centris bicornuta Muscáry), has been observed nesting in new nest cavities drilled into wooden blocks placed next to cavities used by another female within 2-3 days. In contrast, new nest cavities placed in similar areas with no nesting Centris nearby were not used for weeks. These observations suggest that the presence of nesting bees may play a role in nest site selection. To confirm our observations, new nest cavities were placed in areas with or without nesting. We found nest initiation in newly placed nest cavities only in areas where bees were actively nesting. To examine the possibility that nesting locations are not unique, we placed new nest cavities in new locations either with (a) a number of completed nest cavities or (b) placed alone. Within three days we only found bees nesting in the newly placed nest cavities in situation "a". The results suggested that odor might be involved. We next compared nesting in new cavities placed alone with cavities contaminated with either (a) nest entrance plug material, (b) nest nectar, (c) nest pollen or (d) a combination of pollen and nectar. Nesting was significantly low in cavities placed next to cavities with nest entrance plug material (a), and high in cavities placed next to cavities "b, c, or d". The results suggest that pollen and /or nectar odor play a role in the location of potential nest sites. PMID:21584397

  8. Community Ecology of Euglossine Bees in the Coastal Atlantic Forest of São Paulo State, Brazil

    PubMed Central

    da Rocha-Filho, Léo Correia; Garofalo, Carlos Alberto

    2013-01-01

    The Atlantic Forest stretches along Brazil's Atlantic coast, from Rio Grande do Norte State in the north to Rio Grande do Sul State in the south, and inland as far as Paraguay and the Misiones Province of Argentina. This biome is one of the eight biodiversity hotspots in the world and is characterized by high species diversity. Euglossini bees are known as important pollinators in this biome, where their diversity is high. Due to the high impact of human activities in the Atlantic Forest, in the present study the community structure of Euglossini was assessed in a coastal lowland area, Parque Estadual da Serra do Mar - Núcleo Picinguaba (PESM), and in an island, Parque Estadual da Ilha Anchieta (PEIA), Ubatuba, São Paulo State, Brazil. Sampling was carried out monthly, from August 2007 to July 2009, using artificial baits with 14 aromatic compounds to attract males. Twenty-three species were recorded. On PEIA, Euglossa cordata (L.) (Hymenoptera: Apidae) represented almost two thirds of the total species collected (63.2%). Euglossa iopoecila (23.0%) was the most abundant species in PESM but was not recorded on the island, and Euglossa sapphirina (21.0%) was the second most frequent species in PESM but was represented by only nine individuals on PEIA. The results suggest that these two species may act as bioindicators of preserved environments, as suggested for other Euglossini species. Some authors showed that Eg. cordata is favored by disturbed environments, which could explain its high abundance on Anchieta Island. Similarly, as emphasized by other authors, the dominance of Eg. cordata on the island would be another factor indicative of environmental disturbance. PMID:23901873

  9. Hawaii Forest Bird Interagency Database Project: Collecting, Understanding, and Sharing Population Data on Hawaiian Forest Birds

    USGS Publications Warehouse

    Pratt, Thane K.; Woodworth, Bethany L.; Camp, Richard J.; Gorresen, P. Marcos

    2006-01-01

    The forest birds of the Hawaiian Islands are distinguished by the diversity of endemic forms derived from a small number of ancestral colonists. However, the avifauna has been decimated by human activities both before and after Western contact. At least 71 species or subspecies disappeared before the arrival of Capt. James Cook in 1778, and an additional 24 went extinct after 1778, of which 11 were lost since the 1960s alone. Many of the remaining Hawaiian bird populations are declining or are in danger of extinction. Vigorous efforts to survey and monitor bird populations over the past 3 decades have generated considerable information from which to assess the current status of the Hawaiian forest birds.

  10. The orchid-bee fauna (Hymenoptera: Apidae) of a forest remnant in the southern portion of the Brazilian Amazon.

    PubMed

    Santos Júnior, J E; Ferrari, R R; Nemésio, A

    2014-08-01

    The orchid-bee fauna of the region of Porto Velho, in the state of Rondônia, Brazil, close to the southernmost limits of the Amazon Basin, was surveyed for the first time using five different scents as baits to attract orchid-bee males. Five hundred and twenty-one males belonging to five genera and 29 species were collected with bait traps during 26 non-consecutive days from November, 2011 to January, 2012. Eulaema nigrita Lepeletier, 1841 and Eulaema meriana (Olivier, 1789) were the most common species in the region and, together, represented almost 50% of all collected bees. Although the observed richness conforms to similar inventories in the region, the diversity (H'= 2.43) found in the present study is one of the highest ever recorded for orchid bees in the Amazon Basin.

  11. Autumn invasion rates of Varroa destructor (Mesostigmata: Varroidae) into honey bee (Hymenoptera: Apidae) colonies and the resulting increase in mite populations.

    PubMed

    Frey, Eva; Rosenkranz, Peter

    2014-04-01

    The honey bee parasite Varroa destructor Anderson & Trueman can disperse and invade honey bee colonies by attaching to "drifting" and "robbing" honey bees that move into nonnatal colonies. We quantified the weekly invasion rates and the subsequent mite population growth from the end of July to November 2011 in 28 honey bee colonies kept in two apiaries that had high (HBD) and low (LBD) densities of neighboring colonies. At each apiary, half (seven) of the colonies were continuously treated with acaricides to kill all Varroa mites and thereby determine the invasion rates. The other group of colonies was only treated before the beginning of the experiment and then left untreated to record Varroa population growth until a final treatment in November. The numbers of bees and brood cells of all colonies were estimated according to the Liebefeld evaluation method. The invasion rates varied among individual colonies but revealed highly significant differences between the study sites. The average invasion rate per colony over the entire 3.5-mo period ranged from 266 to 1,171 mites at the HBD site compared with only 72 to 248 mites at the LBD apiary. In the untreated colonies, the Varroa population reached an average final infestation in November of 2,082 mites per colony (HBD) and 340 mites per colony (LBD). All colonies survived the winter; however, the higher infested colonies lost about three times more bees compared with the lower infested colonies. Therefore, mite invasion and late-year population growth must be considered more carefully for future treatment concepts in temperate regions.

  12. Population-genomic variation within RNA viruses of the Western honey bee, Apis mellifera, inferred from deep sequencing

    PubMed Central

    2013-01-01

    Background Deep sequencing of viruses isolated from infected hosts is an efficient way to measure population-genetic variation and can reveal patterns of dispersal and natural selection. In this study, we mined existing Illumina sequence reads to investigate single-nucleotide polymorphisms (SNPs) within two RNA viruses of the Western honey bee (Apis mellifera), deformed wing virus (DWV) and Israel acute paralysis virus (IAPV). All viral RNA was extracted from North American samples of honey bees or, in one case, the ectoparasitic mite Varroa destructor. Results Coverage depth was generally lower for IAPV than DWV, and marked gaps in coverage occurred in several narrow regions (< 50 bp) of IAPV. These coverage gaps occurred across sequencing runs and were virtually unchanged when reads were re-mapped with greater permissiveness (up to 8% divergence), suggesting a recurrent sequencing artifact rather than strain divergence. Consensus sequences of DWV for each sample showed little phylogenetic divergence, low nucleotide diversity, and strongly negative values of Fu and Li’s D statistic, suggesting a recent population bottleneck and/or purifying selection. The Kakugo strain of DWV fell outside of all other DWV sequences at 100% bootstrap support. IAPV consensus sequences supported the existence of multiple clades as had been previously reported, and Fu and Li’s D was closer to neutral expectation overall, although a sliding-window analysis identified a significantly positive D within the protease region, suggesting selection maintains diversity in that region. Within-sample mean diversity was comparable between the two viruses on average, although for both viruses there was substantial variation among samples in mean diversity at third codon positions and in the number of high-diversity sites. FST values were bimodal for DWV, likely reflecting neutral divergence in two low-diversity populations, whereas IAPV had several sites that were strong outliers with very low

  13. Use of RAPD analyses to estimate population genetic parameters in the alfalfa leaf-cutting bee, Megachile rotundata.

    PubMed

    Lu, R; Rank, G H

    1996-08-01

    RAPD analyses were performed on five geographically isolated populations of Megachile rotundata. We used haploid males of the alfalfa leaf-cutting bee, M. rotundata, to overcome the limitation of the dominance of RAPD markers in the determination of population genetic parameters. Sixteen primers gave rise to 130 polymorphic and 31 monomorphic bands. The unbiased estimators calculated in this study include within- and between-population heterozygosity, nucleotide divergence, and genetic distance. The genetic diversity (H = 0.32-0.35) was found to be about 10 times that of previous estimates (H = 0.033) based on allozyme data. Contrary to the data obtained at the protein level, our results suggest that Hymenoptera do not have a lower level of genetic variability at the DNA level compared with other insect species. Regardless of the different assumptions underlying the calculation of heterozygosity, divergence, and genetic distance, all five populations showed a parallel interrelationship for the three parameters. We conclude that RAPD markers are a convenient tool to estimate population genetic variation in haploid M. rotundata and that with an adequate sample size the technique is applicable to the evaluation of divergence in diploid populations. Key words : Megachile rotundata, RAPD, heterozygosity, genetic distance, nucleotide divergence. PMID:18469925

  14. Towards integration of population and comparative genomics in forest trees.

    PubMed

    Ingvarsson, Pär K; Hvidsten, Torgeir R; Street, Nathaniel R

    2016-10-01

    Contents 338 I. 338 II. 339 III. 340 IV. 342 343 References 343 SUMMARY: The past decade saw the initiation of an ongoing revolution in sequencing technologies that is transforming all fields of biology. This has been driven by the advent and widespread availability of high-throughput, massively parallel short-read sequencing (MPS) platforms. These technologies have enabled previously unimaginable studies, including draft assemblies of the massive genomes of coniferous species and population-scale resequencing. Transcriptomics studies have likewise been transformed, with RNA-sequencing enabling studies in nonmodel organisms, the discovery of previously unannotated genes (novel transcripts), entirely new classes of RNAs and previously unknown regulatory mechanisms. Here we touch upon current developments in the areas of genome assembly, comparative regulomics and population genetics as they relate to studies of forest tree species. PMID:27575589

  15. Varroa destructor (Mesostigmata: Varroidae) in Costa Rica: population dynamics and its influence on the colony condition of Africanized honey bees (Hymenoptera: Apidae).

    PubMed

    Calderón, Rafael A; van Veen, Johan W

    2008-12-01

    The development of Varroa destructor Anderson & Trueman (Mesostigmata: Varroidae) population dynamics in Africanized honey bees, Apis mellifera L. (Hymenoptera: Apidae) colonies was monitored from February to July 2004 in Atenas, Costa Rica. A correlation between the mite infestation level and the colony condition was evaluated. For each colony, infestation of varroa in adult bees was measured twice a month. Sticky boards were placed on the bottom boards of each colony to collect fallen mites. The condition of the colonies was evaluated by measuring the amount of brood and adult bees. Our results consistently showed that mite infestation on adult bees increased significantly in the experimental colonies, rising to 10.0% by the end of the experiment. In addition, the mean mite fall increased significantly over the course of the study in the treated (R = 0.72, P < 0.05) and untreated colonies (R = 0.74, P < 0.05) to a level of 63.8 and 73.5 mites per day, respectively. The increase in varroa infestation coincided with a decrease in the amount of brood. Furthermore, adult bees with deformed wings or even without wings crawling in front of their hive occurred in highly infested colonies (mite infestation = 10.0% or more).

  16. The trail pheromone of a stingless bee, Trigona corvina (Hymenoptera, Apidae, Meliponini), varies between populations.

    PubMed

    Jarau, Stefan; Dambacher, Jochen; Twele, Robert; Aguilar, Ingrid; Francke, Wittko; Ayasse, Manfred

    2010-09-01

    Stingless bees, like honeybees, live in highly organized, perennial colonies. Their eusocial way of life, which includes division of labor, implies that only a fraction of the workers leave the nest to forage for food. To ensure a sufficient food supply for all colony members, stingless bees have evolved different mechanisms to recruit workers to foraging or even to communicate the location of particular food sites. In some species, foragers deposit pheromone marks between food sources and their nest, which are used by recruited workers to locate the food. To date, pheromone compounds have only been described for 3 species. We have identified the trail pheromone of a further species by means of chemical and electrophysiological analyses and with bioassays testing natural gland extracts and synthetic compounds. The pheromone is a blend of wax type and terpene esters. The relative proportions of the single components showed significant differences in the pheromones of foragers form 3 different colonies. This is the first report on a trail pheromone comprised of esters of 2 different biogenetic origins proving variability of the system. Pheromone specificity may serve to avoid confusions between the trails deposited by foragers of different nests and, thus, to decrease competition at food sources.

  17. Molecular epidemiology and population structure of the honey bee brood pathogen Melissococcus plutonius

    PubMed Central

    Budge, Giles E; Shirley, Mark D F; Jones, Benjamin; Quill, Emiline; Tomkies, Victoria; Feil, Edward J; Brown, Mike A; Haynes, Edward G

    2014-01-01

    Melissococcus plutonius is the causative agent of European foulbrood (EFB), which is a serious brood disease of the European honey bee (Apis mellifera). EFB remains a threat because of a poor understanding of disease epidemiology. We used a recently published multi-locus sequence typing method to characterise 206 M. plutonius isolates recovered from outbreaks in England and Wales over the course of 2 years. We detected 15 different sequence types (STs), which were resolved by eBURST and phylogenetic analysis into three clonal complexes (CCs) 3, 12 and 13. Single and double locus variants within CC3 were the most abundant and widespread genotypes, accounting for 85% of the cases. In contrast, CCs 12 and 13 were rarer and predominantly found in geographical regions of high sampling intensity, consistent with a more recent introduction and localised spread. K-function analysis and interpoint distance tests revealed significant geographical clustering in five common STs, but pointed to different dispersal patterns between STs. We noted that CCs appeared to vary in pathogenicity and that infection caused by the more pathogenic variants is more likely to lead to honey bee colony destruction, as opposed to treatment. The importance of these findings for improving our understanding of disease aetiology and control are discussed. PMID:24599072

  18. Characterization of viral siRNA populations in honey bee colony collapse disorder.

    PubMed

    Chejanovsky, Nor; Ophir, Ron; Schwager, Michal Sharabi; Slabezki, Yossi; Grossman, Smadar; Cox-Foster, Diana

    2014-04-01

    Colony Collapse Disorder (CCD), a special case of collapse of honey bee colonies, has resulted in significant losses for beekeepers. CCD-colonies show abundance of pathogens which suggests that they have a weakened immune system. Since honey bee viruses are major players in colony collapse and given the important role of viral RNA interference (RNAi) in combating viral infections we investigated if CCD-colonies elicit an RNAi response. Deep-sequencing analysis of samples from CCD-colonies from US and Israel revealed abundant small interfering RNAs (siRNA) of 21-22 nucleotides perfectly matching the Israeli acute paralysis virus (IAPV), Kashmir virus and Deformed wing virus genomes. Israeli colonies showed high titers of IAPV and a conserved RNAi-pattern of matching the viral genome. That was also observed in sample analysis from colonies experimentally infected with IAPV. Our results suggest that CCD-colonies set out a siRNA response that is specific against predominant viruses associated with colony losses.

  19. The trail pheromone of a stingless bee, Trigona corvina (Hymenoptera, Apidae, Meliponini), varies between populations.

    PubMed

    Jarau, Stefan; Dambacher, Jochen; Twele, Robert; Aguilar, Ingrid; Francke, Wittko; Ayasse, Manfred

    2010-09-01

    Stingless bees, like honeybees, live in highly organized, perennial colonies. Their eusocial way of life, which includes division of labor, implies that only a fraction of the workers leave the nest to forage for food. To ensure a sufficient food supply for all colony members, stingless bees have evolved different mechanisms to recruit workers to foraging or even to communicate the location of particular food sites. In some species, foragers deposit pheromone marks between food sources and their nest, which are used by recruited workers to locate the food. To date, pheromone compounds have only been described for 3 species. We have identified the trail pheromone of a further species by means of chemical and electrophysiological analyses and with bioassays testing natural gland extracts and synthetic compounds. The pheromone is a blend of wax type and terpene esters. The relative proportions of the single components showed significant differences in the pheromones of foragers form 3 different colonies. This is the first report on a trail pheromone comprised of esters of 2 different biogenetic origins proving variability of the system. Pheromone specificity may serve to avoid confusions between the trails deposited by foragers of different nests and, thus, to decrease competition at food sources. PMID:20534775

  20. Role of temperate forest heterogeneity in determining the population ecology of Peromyscus leucopus

    SciTech Connect

    Ormiston, B.G.

    1980-11-01

    Population density levels of small mammals are often roughly correlated with local forest productivity. In a highly productive forest the total number of individual small mammals (all species) may exceed 100/hectare. Low productivity forests may harbor few or none at all. Thus, the potential exists for using small mammal populations as indicators of local forest composition and quality. Changes in the density levels of species used for this purpose (indicator species) may so reflect the dynamics of forest structure and productivity. The white-footed mouse, Peromyscus leucopus, is common in temperate deciduous forests throughout the northeastern United States. Its ubiquitous distribution is a required feature for studying the effects of variation in forest components upon a representative consumer. The goal of this study was to collect baseline data on P. leucopus populations responding to spatial and temporal forest heterogeneity, and so evaluate its potential as an indicator species.

  1. Fine scale population genetic structure of Varroa destructor, an ectoparasitic mite of the honey bee (Apis mellifera)

    PubMed Central

    Dynes, Travis L.; De Roode, Jacobus C.; Lyons, Justine I.; Berry, Jennifer A.; Delaplane, Keith S.; Brosi, Berry J.

    2016-01-01

    Varroa destructor is an obligate ectoparasitic mite and the most important biotic threat currently facing honey bees (Apis mellifera). We used neutral microsatellites to analyze previously unreported fine scale population structure of V. destructor, a species characterized by extreme lack of genetic diversity owing to multiple bottleneck events, haplodiploidy, and primarily brother-sister matings. Our results surprisingly indicate that detectable hierarchical genetic variation exists between apiaries, between colonies within an apiary, and even within colonies. This finding of within-colony parasite diversity provides empirical evidence that the spread of V. destructor is not accomplished solely by vertical transmission but that horizontal transmission (natural or human-mediated) must occur regularly. PMID:27812229

  2. Distinct subspecies or phenotypic plasticity? Genetic and morphological differentiation of mountain honey bees in East Africa

    PubMed Central

    Gruber, Karl; Schöning, Caspar; Otte, Marianne; Kinuthia, Wanja; Hasselmann, Martin

    2013-01-01

    Identifying the forces shaping intraspecific phenotypic and genotypic divergence are of key importance in evolutionary biology. Phenotypic divergence may result from local adaptation or, especially in species with strong gene flow, from pronounced phenotypic plasticity. Here, we examine morphological and genetic divergence among populations of the western honey bee Apis mellifera in the topographically heterogeneous East African region. The currently accepted “mountain refugia hypothesis” states that populations living in disjunct montane forests belong to a different lineage than those in savanna habitats surrounding these forests. We obtained microsatellite data, mitochondrial sequences, and morphometric data from worker honey bees collected from feral colonies in three montane forests and corresponding neighboring savanna regions in Kenya. Honey bee colonies from montane forests showed distinct worker morphology compared with colonies in savanna areas. Mitochondrial sequence data did not support the existence of the two currently accepted subspecies. Furthermore, analyses of the microsatellite data with a Bayesian clustering method did not support the existence of two source populations as it would be expected under the mountain refugia scenario. Our findings suggest that phenotypic plasticity rather than distinct ancestry is the leading cause behind the phenotypic divergence observed between montane forest and savanna honey bees. Our study thus corroborates the idea that high gene flow may select for increased plasticity. PMID:24223262

  3. Oskar and Cécile Vogt, Lenin's brain and the bumble-bees of the Black Forest.

    PubMed

    Kreutzberg, G W; Klatzo, I; Kleihues, P

    1992-10-01

    Oskar Vogt (1870-1955) was a prominent German neurologist and neuroanatomist with a strong interest in the pathogenesis of brain diseases. Together with his wife Cécile (1875-1962), he published landmark papers on the cyto- and myelo-architecture of the brain and the functional anatomy of the basal ganglia. He developed the concept of pathoclisis, i.e., the selective vulnerability of specific neuronal populations in the CNS. In the 1920's, Vogt created a multi-disciplinary brain research institute, the Kaiser-Wilhelm-Institut für Hirnforschung in Berlin-Buch. After Lenin's death in 1924, Oskar Vogt was called to Moscow where he formed a new brain research institute, with the main purpose to investigate the revolutionary's brain. After being dismissed from office by the Nazi government in 1937, the Vogts continued their work in a privately funded institute in Neustadt, the Black Forest.

  4. Comparison of neotropical migrant landbird populations wintering in tropical forest, isolated forest fragments, and agricultural habitats

    USGS Publications Warehouse

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.; Colon, J.A.; Estrada, R.; Sutton, A.; Sutton, R.; Weyer, D.; Hagan, John M.; Johnston, David W.

    1992-01-01

    Neotropical migrant bird populations were sampled at 76 sites in seven countries by using mist nets and point counts during a six-winter study. Populations in major agricultural habitats were compared with those in extensive forest and isolated forest fragments. Certain Neotropical migrants, such as the Northern Parula, American Redstart, and the Black-throated Blue, Magnolia, Black-and-white, and Hooded warblers, were present in arboreal agricultural habitats such as pine, cacao, citrus, and shade coffee plantations in relatively large numbers. Many north temperate zone shrub-nesting species, such as the Gray Catbird, White-eyed Vireo, Tennessee Warbler, Common Yellowthroat, and Indigo Bunting, also used agricultural habitats in winter, as did resident hummingbirds and migrant orioles. Ground-foraging migrants, such as thrushes and Kentucky Warblers, were rarely found in the agricultural habitats sampled. Although many Neotropical migrants use some croplands, this use might be severely limited by overgrazing by cattle, by intensive management (such as removal of ground cover in an orchard), or by heavy use of insecticides, herbicides, or fungicides.

  5. [Populational chromosomal polymorphism the Asian forest mouse Apodemus peninsulae].

    PubMed

    Bekasova, T S; Vorontsov, N N

    1975-01-01

    29 individuals of Apodemus peninsulae, an Asian forest mouse from the Suputin State Nature Reserve (Maritime Territory) were studied karyologically. Diploid chromosome sets of the animals studied contained from 48 to 52 chromosomes. The difference in the diploid chromosome numbers is caused by the presence in some individuals of supernumerary metacentric chromosomes (up to 4). The set is always represented by 48 acrocentric chromosomes, gradually decreasing in size. The supernumerary metacentric chromosomes vary in size from medium-sized to the smallest in the set. The character of intrapopulational chromosome polymorphism of continental and island populations of Apodemus peninsulae is discussed. Attempts are made to explain the polymorphism with respect to supernumerary chromosomes as the result of some viral diseases.

  6. Impact of managed honey bee viruses on wild bees.

    PubMed

    Tehel, Anja; Brown, Mark Jf; Paxton, Robert J

    2016-08-01

    Several viruses found in the Western honey bee (Apis mellifera) have recently been detected in other bee species, raising the possibility of spill-over from managed to wild bee species. Alternatively, these viruses may be shared generalists across flower-visiting insects. Here we explore the former hypothesis, pointing out weaknesses in the current evidence, particularly in relation to deformed wing virus (DWV), and highlighting research areas that may help test it. Data so far suggest that DWV spills over from managed to wild bee species and has the potential to cause population decline. That DWV and other viruses of A. mellifera are found in other bee species needs to be considered for the sustainable management of bee populations.

  7. Impact of managed honey bee viruses on wild bees.

    PubMed

    Tehel, Anja; Brown, Mark Jf; Paxton, Robert J

    2016-08-01

    Several viruses found in the Western honey bee (Apis mellifera) have recently been detected in other bee species, raising the possibility of spill-over from managed to wild bee species. Alternatively, these viruses may be shared generalists across flower-visiting insects. Here we explore the former hypothesis, pointing out weaknesses in the current evidence, particularly in relation to deformed wing virus (DWV), and highlighting research areas that may help test it. Data so far suggest that DWV spills over from managed to wild bee species and has the potential to cause population decline. That DWV and other viruses of A. mellifera are found in other bee species needs to be considered for the sustainable management of bee populations. PMID:27351468

  8. Candida riodocensis and Candida cellae, two new yeast species from the Starmerella clade associated with solitary bees in the Atlantic rain forest of Brazil.

    PubMed

    Pimentel, Mariana R C; Antonini, Yasmine; Martins, Rogério P; Lachance, Marc-André; Rosa, Carlos A

    2005-06-01

    Two new ascomycetous yeast species belonging to the Starmerella clade were discovered in nests of two solitary bee species in the Atlantic rain forest of Brazil. Candida riodocensis was isolated from pollen-nectar provisions, larvae and fecal pellets of nests of Megachile sp., and Candida cellae was found in pollen-nectar provisions of Centris tarsata. Analysis of the sequences of the D1/D2 large-subunit ribosomal DNA showed that C. riodocensis is phylogenetically related to C. batistae, and the closest relative of C. cellae is C. etchellsii. The type strains are C. riodocensis UFMG-MG02 (=CBS 10087(T) = NRRL Y-27859(T)) and C. cellae UFMG-PC04 (=CBS 10086(T) = NRRL Y-27860(T)). PMID:15925316

  9. Lower Virus Infections in Varroa destructor-Infested and Uninfested Brood and Adult Honey Bees (Apis mellifera) of a Low Mite Population Growth Colony Compared to a High Mite Population Growth Colony

    PubMed Central

    Emsen, Berna; Hamiduzzaman, Mollah Md.; Goodwin, Paul H.; Guzman-Novoa, Ernesto

    2015-01-01

    A comparison was made of the prevalence and relative quantification of deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), black queen cell virus (BQCV), Kashmir bee virus (KBV), acute bee paralysis virus (ABPV) and sac brood virus (SBV) in brood and adult honey bees (Apis mellifera) from colonies selected for high (HMP) and low (LMP) Varroa destructor mite population growth. Two viruses, ABPV and SBV, were never detected. For adults without mite infestation, DWV, IAPV, BQCV and KBV were detected in the HMP colony; however, only BQCV was detected in the LMP colony but at similar levels as in the HMP colony. With mite infestation, the four viruses were detected in adults of the HMP colony but all at higher amounts than in the LMP colony. For brood without mite infestation, DWV and IAPV were detected in the HMP colony, but no viruses were detected in the LMP colony. With mite infestation of brood, the four viruses were detected in the HMP colony, but only DWV and IAPV were detected and at lower amounts in the LMP colony. An epidemiological explanation for these results is that pre-experiment differences in virus presence and levels existed between the HMP and LMP colonies. It is also possible that low V. destructor population growth in the LMP colony resulted in the bees being less exposed to the mite and thus less likely to have virus infections. LMP and HMP bees may have also differed in susceptibility to virus infection. PMID:25723540

  10. Lower virus infections in Varroa destructor-infested and uninfested brood and adult honey bees (Apis mellifera) of a low mite population growth colony compared to a high mite population growth colony.

    PubMed

    Emsen, Berna; Hamiduzzaman, Mollah Md; Goodwin, Paul H; Guzman-Novoa, Ernesto

    2015-01-01

    A comparison was made of the prevalence and relative quantification of deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), black queen cell virus (BQCV), Kashmir bee virus (KBV), acute bee paralysis virus (ABPV) and sac brood virus (SBV) in brood and adult honey bees (Apis mellifera) from colonies selected for high (HMP) and low (LMP) Varroa destructor mite population growth. Two viruses, ABPV and SBV, were never detected. For adults without mite infestation, DWV, IAPV, BQCV and KBV were detected in the HMP colony; however, only BQCV was detected in the LMP colony but at similar levels as in the HMP colony. With mite infestation, the four viruses were detected in adults of the HMP colony but all at higher amounts than in the LMP colony. For brood without mite infestation, DWV and IAPV were detected in the HMP colony, but no viruses were detected in the LMP colony. With mite infestation of brood, the four viruses were detected in the HMP colony, but only DWV and IAPV were detected and at lower amounts in the LMP colony. An epidemiological explanation for these results is that pre-experiment differences in virus presence and levels existed between the HMP and LMP colonies. It is also possible that low V. destructor population growth in the LMP colony resulted in the bees being less exposed to the mite and thus less likely to have virus infections. LMP and HMP bees may have also differed in susceptibility to virus infection.

  11. Competitive interactions between neotropical pollinators and africanized honey bees.

    PubMed

    Roubik, D W

    1978-09-15

    The Africanized honey bee, a hybrid of European and African honey bees, is thought to displace native pollinators. After experimental introduction of Africanized honey bee hives near flowers, stingless bees became less abundant or harvested-less resource as visitation by Africanized honey bees increased. Shifts in resource use caused by colonizing Africanized honey bees may lead to population decline of Neotropical pollinators. PMID:17743636

  12. Importance of climate, forest fires and human population size on the long-term boreal forest dynamics in Northern Europe

    NASA Astrophysics Data System (ADS)

    Kuosmanen, Niina; Seppä, Heikki; Alenius, Teija; Bradshaw, Richard; Clear, Jennifer; Filimonova, Fludmila; Heikkilä, Maija; Renssen, Hans; Tallavaara, Miikka; Reitalu, Triin

    2016-04-01

    Palaeoecological data provides valuable information for understanding the processes behind the past changes in forest composition, and hence can provide important knowledge regarding the potential effects of future changes in climate on boreal vegetation. Furthermore, it is essential to consider both regional and local factors in order to better understand the processes behind the boreal forest dynamics. The relative importance of climate, forest fires and human population size on long-term boreal forest composition were statistically investigated at regional and local scales in Fennoscandia. Statistical method variation partitioning was employed to assess the relative importance of these three variables. Fossil pollen data reflecting long-term boreal forest composition, at both regional (lake records) and local (small hollow records) scales from Russia, Finland and Sweden, were used as response matrix. Climate, generated from a climate model and oxygen isotope data, past forest fires generated from sedimentary charcoal data and human population size derived from radiocarbon dated archaeological findings were used as potential drivers of long-term boreal vegetation. Though the results clearly demonstrate that climate is the main driver of long-term vegetation changes at the regional scale, the role of climate notably is smaller at local scale and the influence of local site specific factors increases. However, the relative importance of forest fires on long-term changes in boreal forest composition remain generally low both at regional and local scale. The relatively low importance of both climate and forest fires on the variation in long-term boreal forest composition at local scale demonstrates the complexity of factors affecting stand-scale forest dynamics. In general, the relative importance of human population size on long-term changes in boreal vegetation was low. However, this was the first time that this type of human population size data was statistically

  13. Interspecific geographic distribution and variation of two bumble bee pathogens, Nosema bombi and Crithidia bombi, in United States populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several bumble bee (Bombus) species in North America have undergone range reductions and rapid declines in relative abundance. Pathogens have been suggested as causal factors, however, baseline data on pathogen distributions in a large number of bumble bee species have not been available to rigorous...

  14. Influences of soil acidity on Streptomyces populations inhabiting forest soils.

    PubMed Central

    Hagedorn, C

    1976-01-01

    The Streptomyces populations inhabiting five acidic forest soils were examined. It was found that lowering the pH of a medium selective for streptomycetes (starch-casein agar) to the pH of the particular soil horizon being plated influenced both the total numbers and types of streptomycetes that were isolated from the soils examined in this study. On the acidified medium both the numbers of streptomycetes and the percentage of total bacteria on the plates represented by streptomycetes increased (as compared with the same medium with a pH of 7.2). These differences were greatest on the isolations from the most acid soils. The largest concentrations of streptomycetes were found in the surface horizon (0 to 15 cm) and the litter layer immediately over the surface mineral horizon. Acidity tolerance tests demonstrated that random samplings of isolates contained acidophilic, neutrophilic, and acidoduric strains, with the largest numbers of acidophiles being found on the acidified media from the most acid soils. There were no differences between overall utilization of selected carbohydrates among the isolates taken from either the neutral or acidic media, although a larger proportion of the acid media isolates produced acid from the carbohydrates. Evidence is presented which indicates that different types of streptomycetes were isolated on the acid media, and possible reasons for the presence of these acid-tolerant populations are discussed. PMID:10835

  15. Bee Pollen

    MedlinePlus

    ... bee venom, honey, or royal jelly. People take bee pollen for nutrition; as an appetite stimulant; to improve stamina and athletic performance; and for premature aging, premenstrual syndrome (PMS), hay fever (allergic ... Bee pollen is also used for gastrointestinal (GI) problems ...

  16. Population genomics of the honey bee reveals strong signatures of positive selection on worker traits.

    PubMed

    Harpur, Brock A; Kent, Clement F; Molodtsova, Daria; Lebon, Jonathan M D; Alqarni, Abdulaziz S; Owayss, Ayman A; Zayed, Amro

    2014-02-18

    Most theories used to explain the evolution of eusociality rest upon two key assumptions: mutations affecting the phenotype of sterile workers evolve by positive selection if the resulting traits benefit fertile kin, and that worker traits provide the primary mechanism allowing social insects to adapt to their environment. Despite the common view that positive selection drives phenotypic evolution of workers, we know very little about the prevalence of positive selection acting on the genomes of eusocial insects. We mapped the footprints of positive selection in Apis mellifera through analysis of 40 individual genomes, allowing us to identify thousands of genes and regulatory sequences with signatures of adaptive evolution over multiple timescales. We found Apoidea- and Apis-specific genes to be enriched for signatures of positive selection, indicating that novel genes play a disproportionately large role in adaptive evolution of eusocial insects. Worker-biased proteins have higher signatures of adaptive evolution relative to queen-biased proteins, supporting the view that worker traits are key to adaptation. We also found genes regulating worker division of labor to be enriched for signs of positive selection. Finally, genes associated with worker behavior based on analysis of brain gene expression were highly enriched for adaptive protein and cis-regulatory evolution. Our study highlights the significant contribution of worker phenotypes to adaptive evolution in social insects, and provides a wealth of knowledge on the loci that influence fitness in honey bees.

  17. Population genomics of the honey bee reveals strong signatures of positive selection on worker traits.

    PubMed

    Harpur, Brock A; Kent, Clement F; Molodtsova, Daria; Lebon, Jonathan M D; Alqarni, Abdulaziz S; Owayss, Ayman A; Zayed, Amro

    2014-02-18

    Most theories used to explain the evolution of eusociality rest upon two key assumptions: mutations affecting the phenotype of sterile workers evolve by positive selection if the resulting traits benefit fertile kin, and that worker traits provide the primary mechanism allowing social insects to adapt to their environment. Despite the common view that positive selection drives phenotypic evolution of workers, we know very little about the prevalence of positive selection acting on the genomes of eusocial insects. We mapped the footprints of positive selection in Apis mellifera through analysis of 40 individual genomes, allowing us to identify thousands of genes and regulatory sequences with signatures of adaptive evolution over multiple timescales. We found Apoidea- and Apis-specific genes to be enriched for signatures of positive selection, indicating that novel genes play a disproportionately large role in adaptive evolution of eusocial insects. Worker-biased proteins have higher signatures of adaptive evolution relative to queen-biased proteins, supporting the view that worker traits are key to adaptation. We also found genes regulating worker division of labor to be enriched for signs of positive selection. Finally, genes associated with worker behavior based on analysis of brain gene expression were highly enriched for adaptive protein and cis-regulatory evolution. Our study highlights the significant contribution of worker phenotypes to adaptive evolution in social insects, and provides a wealth of knowledge on the loci that influence fitness in honey bees. PMID:24488971

  18. Population genomics of the honey bee reveals strong signatures of positive selection on worker traits

    PubMed Central

    Harpur, Brock A.; Kent, Clement F.; Molodtsova, Daria; Lebon, Jonathan M. D.; Alqarni, Abdulaziz S.; Owayss, Ayman A.; Zayed, Amro

    2014-01-01

    Most theories used to explain the evolution of eusociality rest upon two key assumptions: mutations affecting the phenotype of sterile workers evolve by positive selection if the resulting traits benefit fertile kin, and that worker traits provide the primary mechanism allowing social insects to adapt to their environment. Despite the common view that positive selection drives phenotypic evolution of workers, we know very little about the prevalence of positive selection acting on the genomes of eusocial insects. We mapped the footprints of positive selection in Apis mellifera through analysis of 40 individual genomes, allowing us to identify thousands of genes and regulatory sequences with signatures of adaptive evolution over multiple timescales. We found Apoidea- and Apis-specific genes to be enriched for signatures of positive selection, indicating that novel genes play a disproportionately large role in adaptive evolution of eusocial insects. Worker-biased proteins have higher signatures of adaptive evolution relative to queen-biased proteins, supporting the view that worker traits are key to adaptation. We also found genes regulating worker division of labor to be enriched for signs of positive selection. Finally, genes associated with worker behavior based on analysis of brain gene expression were highly enriched for adaptive protein and cis-regulatory evolution. Our study highlights the significant contribution of worker phenotypes to adaptive evolution in social insects, and provides a wealth of knowledge on the loci that influence fitness in honey bees. PMID:24488971

  19. Development of a species-diagnostic marker and its application for population genetics studies of the stingless bee Trigona collina in Thailand.

    PubMed

    Theeraapisakkun, M; Klinbunga, S; Sittipraneed, S

    2010-05-18

    A molecular maker for authenticating species origin of the stingless bee (Trigona collina) was developed. Initially, amplified fragment length polymorphism analysis was made of 11 stingless bee species using 64 primer combinations. A 316-bp band found only in T. collina was cloned and sequenced. A primer pair (CUTc1-F/R) was designed and tested for species-specificity in 15 stingless bee species (239 nests). The expected 259-bp fragment was consistently amplified in all T. collina individuals (134/134 nests, 100%). Cross-species amplification was observed in T. pagdeni (43/51 nests; 84.3%), but not in other species. SSCP analysis of CUTc1 unambiguously differentiated T. collina from T. pagdeni. CUTc1 generated three genotypes in Thai T. collina (134 nests). An AA (259/259 bp) genotype was found in all stingless bees from the north (21 nests) and northeast (32 nests), and 23/28 nests from the Central region, whereas a BB (253/253 bp) genotype was observed in most samples from peninsular Thailand (42/53 nests). Heterozygotes exhibiting the AB (253/259 bp) genotype were observed in 5 of 28 nests from Prachuap Khiri Khan located slightly above the Kra ecotone and 11 of 53 nests originated further south of the Kra ecotone. Genotype distribution patterns of CUTc1 clearly indicated intraspecific population differentiation of Thai T. collina.

  20. Quantifying the detrimental impacts of land-use and management change on European forest bird populations.

    PubMed

    Wade, Amy S I; Barov, Boris; Burfield, Ian J; Gregory, Richard D; Norris, Ken; Butler, Simon J

    2013-01-01

    The ecological impacts of changing forest management practices in Europe are poorly understood despite European forests being highly managed. Furthermore, the effects of potential drivers of forest biodiversity decline are rarely considered in concert, thus limiting effective conservation or sustainable forest management. We present a trait-based framework that we use to assess the detrimental impact of multiple land-use and management changes in forests on bird populations across Europe. Major changes to forest habitats occurring in recent decades, and their impact on resource availability for birds were identified. Risk associated with these changes for 52 species of forest birds, defined as the proportion of each species' key resources detrimentally affected through changes in abundance and/or availability, was quantified and compared to their pan-European population growth rates between 1980 and 2009. Relationships between risk and population growth were found to be significantly negative, indicating that resource loss in European forests is an important driver of decline for both resident and migrant birds. Our results demonstrate that coarse quantification of resource use and ecological change can be valuable in understanding causes of biodiversity decline, and thus in informing conservation strategy and policy. Such an approach has good potential to be extended for predictive use in assessing the impact of possible future changes to forest management and to develop more precise indicators of forest health.

  1. Transcriptional responses in honey bee larvae infected with chalkbrood fungus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diseases and other stress factors working synergistically weaken honey bee health and may play a major role in the losses of bee populations in recent years. Among a large number of bee diseases, chalkbrood has been on the rise. We present here the experimental identification of honey bee genes that...

  2. Assessing grooming behavior of Russian honey bees toward Varroa destructor.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The grooming behavior of Russian bees was compared to Italian bees. Overall, Russian bees had significantly lower numbers of mites than the Italian bees with a mean of 1,937 ± 366 and 5,088 ± 733 mites, respectively. This low mite population in the Russian colonies was probably due to the increased ...

  3. Comparison of neotropical winter bird populations in isolated patches versus extensive forest

    USGS Publications Warehouse

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.; Colon, J.; Espinoza, F.; Rodriguez, J.; Sutton, R.; Vargas, T.

    1987-01-01

    Wintering birds were captured with mist nets at 12 pairs of forested sites in the New World tropics in 1984 and 1985 to compare populations in small isolated woodlands (generally 5-50 ha) with those in extensive forests (> 1,000 ha). Net-hours of effort were similar in large and small sites, as were total birds captured and banded, but species composition was very different. Members of the Todidae, Dendrocolaptidae, Formicariidae and Thraupinae were significantly more common in extensive forest than in small isolated tracts, indicating that these birds are especially vulnerable to effects of forest fragmentation. However, in winter many species of North American migrants, even species that are restricted to extensive forest during the breeding season, were just as common in small forest fragments as in extensive forest. A high percentage of the North American migrants banded in January 1984 (40 to 50 % for some species) were recaptured in 1985.

  4. The conservation and restoration of wild bees.

    PubMed

    Winfree, Rachael

    2010-05-01

    Bees pollinate most of the world's wild plant species and provide economically valuable pollination services to crops; yet knowledge of bee conservation biology lags far behind other taxa such as vertebrates and plants. There are few long-term data on bee populations, which makes their conservation status difficult to assess. The best-studied groups are the genus Bombus (the bumble bees), and bees in the EU generally; both of these are clearly declining. However, it is not known to what extent these groups represent the approximately 20,000 species of bees globally. As is the case for insects in general, bees are underrepresented in conservation planning and protection efforts. For example, only two bee species are on the global IUCN Red List, and no bee is listed under the U.S. Endangered Species Act, even though many bee species are known to be in steep decline or possibly extinct. At present, bee restoration occurs mainly in agricultural contexts, funded by government programs such as agri-environment schemes (EU) and the Farm Bill (USA). This is a promising approach given that many bee species can use human-disturbed habitats, and bees provide valuable pollination services to crops. However, agricultural restorations only benefit species that persist in agricultural landscapes, and they are more expensive than preserving natural habitat elsewhere. Furthermore, such restorations benefit bees in only about half of studied cases. More research is greatly needed in many areas of bee conservation, including basic population biology, bee restoration in nonagricultural contexts, and the identification of disturbance-sensitive bee species.

  5. The conservation and restoration of wild bees.

    PubMed

    Winfree, Rachael

    2010-05-01

    Bees pollinate most of the world's wild plant species and provide economically valuable pollination services to crops; yet knowledge of bee conservation biology lags far behind other taxa such as vertebrates and plants. There are few long-term data on bee populations, which makes their conservation status difficult to assess. The best-studied groups are the genus Bombus (the bumble bees), and bees in the EU generally; both of these are clearly declining. However, it is not known to what extent these groups represent the approximately 20,000 species of bees globally. As is the case for insects in general, bees are underrepresented in conservation planning and protection efforts. For example, only two bee species are on the global IUCN Red List, and no bee is listed under the U.S. Endangered Species Act, even though many bee species are known to be in steep decline or possibly extinct. At present, bee restoration occurs mainly in agricultural contexts, funded by government programs such as agri-environment schemes (EU) and the Farm Bill (USA). This is a promising approach given that many bee species can use human-disturbed habitats, and bees provide valuable pollination services to crops. However, agricultural restorations only benefit species that persist in agricultural landscapes, and they are more expensive than preserving natural habitat elsewhere. Furthermore, such restorations benefit bees in only about half of studied cases. More research is greatly needed in many areas of bee conservation, including basic population biology, bee restoration in nonagricultural contexts, and the identification of disturbance-sensitive bee species. PMID:20536823

  6. Responses of Soil Fungal Populations and Communities to the Thinning of Cryptomeria Japonica Forests

    PubMed Central

    Lin, Wan-Rou; Wang, Pi-Han; Chen, Wen-Cheng; Lai, Chao-Ming; Winder, Richard Scott

    2016-01-01

    Forest management activities, such as tree thinning, alter forest ecology, including key components of forest ecosystems, including fungal communities. In the present study, we investigate the effects of forest thinning intensity on the populations and structures of fungal soil communities in the Cryptomeria japonica forests of central Taiwan as well as the dynamics of soil fungi communities in these forests after a thinning disturbance. Although the populations of soil fungi significantly increased in the first 6 months after thinning, these increases had subsided by 9 months. This pulse was attributed to a transient increase in the populations of rapid colonizers. A multiple regression analysis positively correlated fungal populations with organic matter content and cellulase activity. Thinning initially provided large amounts of fresh leaves and roots as nutrient-rich substrates for soil fungi. Denaturing gradient gel electrophoresis (DGGE) profiles indicated that soil fungal communities significantly differed among plots with 0% (control), 25%, and 50% tree thinning in the first 21 months post-thinning, with no significant differences being observed after 21 months. The fungal communities of these forest soils also changed with the seasons, and an interactive relationship was detected between seasons and treatments. Seasonal variations in fungal communities were the most pronounced after 50% tree thinning. The results of the present study demonstrate that the soil fungi of Taiwanese C. japonica forests are very sensitive to thinning disturbances, but recover stability after a relatively short period of time. PMID:26903369

  7. Native bees and plant pollination

    USGS Publications Warehouse

    Ginsberg, H.S.

    2004-01-01

    Bees are important pollinators, but evidence suggests that numbers of some species are declining. Decreases have been documented in the honey bee, Apis mellifera (which was introduced to North America), but there are no monitoring programs for the vast majority of native species, so we cannot be sure about the extent of this problem. Recent efforts to develop standardized protocols for bee sampling will help us collect the data needed to assess trends in bee populations. Unfortunately, diversity of bee life cycles and phenologies, and the large number of rare species, make it difficult to assess trends in bee faunas. Changes in bee populations can affect plant reproduction, which can influence plant population density and cover, thus potentially modifying horizontal and vertical structure of a community, microclimate near the ground, patterns of nitrogen deposition, etc. These potential effects of changes in pollination patterns have not been assessed in natural communities. Effects of management actions on bees and other pollinators should be considered in conservation planning.

  8. Hitchhiking with forests: population genetics of the epiphytic lichen Lobaria pulmonaria in primeval and managed forests in southeastern Europe

    PubMed Central

    Scheidegger, Christoph; Bilovitz, Peter O; Werth, Silke; Widmer, Ivo; Mayrhofer, Helmut

    2012-01-01

    Availability of suitable trees is a primary determinant of range contractions and expansions of epiphytic species. However, switches between carrier tree species may blur co-phylogeographic patterns. We identified glacial refugia in southeastern Europe for the tree-colonizing lichen Lobaria pulmonaria, studied the importance of primeval forest reserves for the conservation of genetically diverse populations and analyzed differences in spatial genetic structure between primeval and managed forests with fungus-specific microsatellite markers. Populations belonged to either of two genepools or were admixed. Gene diversity was higher in primeval than in managed forests. At small distances up to 170 m, genotype diversity was lower in managed compared with primeval forests. We found significant associations between groups of tree species and two L. pulmonaria genepools, which may indicate “hitchhiking” of L. pulmonaria on forest communities during postglacial migration. Genepool B of L. pulmonaria was associated with European Beech (Fagus sylvatica) and we can hypothesize that genepool B survived the last glaciation associated within the refuge of European Beech on the Coastal and Central Dinarides. The allelic richness of genepool A was highest in the Alps, which is the evidence for a northern refuge of L. pulmonaria. Vicariant altitudinal distributions of the two genepools suggest intraspecific ecological differentiation. PMID:23139881

  9. Population dynamics of the epiphytic bromeliad Tillandsia butzii in cloud forest

    NASA Astrophysics Data System (ADS)

    Toledo-Aceves, Tarin; Hernández-Apolinar, Mariana

    2016-02-01

    Epiphytes are a major component of tropical montane cloud forests. Over-exploitation and forest loss and degradation affect remnant populations. In this study, we analysed the population dynamics of the epiphytic bromeliad Tillandsia butzii over a 2-y period in a tropical montane cloud forest fragment in southern Mexico. Matrix analysis revealed that the T. butzii population is likely to be stable at the study site. On average the λ value did not differ significantly from unity: λ (95% confidence interval) = 0.978 (0.936-1.001). λ was highly influenced by stasis, to a lesser extent by growth and only slightly by fecundity. Overall, adult plant stasis and phalanx growth habit played a fundamental role in population maintenance. T. butzii tolerance to xeric conditions may contribute to population stability in the studied region.

  10. Differential sensitivity of honey bees and bumble bees to a dietary insecticide (imidacloprid).

    PubMed

    Cresswell, James E; Page, Christopher J; Uygun, Mehmet B; Holmbergh, Marie; Li, Yueru; Wheeler, Jonathan G; Laycock, Ian; Pook, Christopher J; de Ibarra, Natalie Hempel; Smirnoff, Nick; Tyler, Charles R

    2012-12-01

    Currently, there is concern about declining bee populations and the sustainability of pollination services. One potential threat to bees is the unintended impact of systemic insecticides, which are ingested by bees in the nectar and pollen from flowers of treated crops. To establish whether imidacloprid, a systemic neonicotinoid and insect neurotoxin, harms individual bees when ingested at environmentally realistic levels, we exposed adult worker bumble bees, Bombus terrestris L. (Hymenoptera: Apidae), and honey bees, Apis mellifera L. (Hymenoptera: Apidae), to dietary imidacloprid in feeder syrup at dosages between 0.08 and 125μg l(-1). Honey bees showed no response to dietary imidacloprid on any variable that we measured (feeding, locomotion and longevity). In contrast, bumble bees progressively developed over time a dose-dependent reduction in feeding rate with declines of 10-30% in the environmentally relevant range of up to 10μg l(-1), but neither their locomotory activity nor longevity varied with diet. To explain their differential sensitivity, we speculate that honey bees are better pre-adapted than bumble bees to feed on nectars containing synthetic alkaloids, such as imidacloprid, by virtue of their ancestral adaptation to tropical nectars in which natural alkaloids are prevalent. We emphasise that our study does not suggest that honey bee colonies are invulnerable to dietary imidacloprid under field conditions, but our findings do raise new concern about the impact of agricultural neonicotinoids on wild bumble bee populations.

  11. Bee poison

    MedlinePlus

    ... stings contain a substance called venom. Africanized bee colonies are very sensitive to being disturbed. When they ... and blood vessels Severe decrease in blood pressure Collapse * Lungs: Difficulty breathing * Skin Hives * Itching Swelling and ...

  12. Decline and conservation of bumble bees.

    PubMed

    Goulson, D; Lye, G C; Darvill, B

    2008-01-01

    Declines in bumble bee species in the past 60 years are well documented in Europe, where they are driven primarily by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of bumble bees and their largely monogamous breeding system, which renders their effective population size low. Hence, populations are susceptible to stochastic extinction events and inbreeding. In North America, catastrophic declines of some bumble bee species since the 1990s are probably attributable to the accidental introduction of a nonnative parasite from Europe, a result of global trade in domesticated bumble bee colonies used for pollination of greenhouse crops. Given the importance of bumble bees as pollinators of crops and wildflowers, steps must be taken to prevent further declines. Suggested measures include tight regulation of commercial bumble bee use and targeted use of environmentally comparable schemes to enhance floristic diversity in agricultural landscapes.

  13. Population density of red langurs in Sabangau tropical peat-swamp forest, Central Kalimantan, Indonesia.

    PubMed

    Ehlers Smith, David A; Ehlers Smith, Yvette C

    2013-08-01

    Because of the large-scale destruction of Borneo's rainforests on mineral soils, tropical peat-swamp forests (TPSFs) are increasingly essential for conserving remnant biodiversity, particularly in the lowlands where the majority of habitat conversion has occurred. Consequently, effective strategies for biodiversity conservation are required, which rely on accurate population density and distribution estimates as a baseline. We sought to establish the first population density estimates of the endemic red langur (Presbytis rubicunda) in Sabangau TPSF, the largest remaining contiguous lowland forest-block on Borneo. Using Distance sampling principles, we conducted line transect surveys in two of Sabangau's three principle habitat sub-classes and calculated group density at 2.52 groups km⁻² (95% CI 1.56-4.08) in the mixed-swamp forest sub-class. Based on an average recorded group size of 6.95 individuals, population density was 17.51 ind km⁻², the second highest density recorded in this species. The accessible area of the tall-interior forest, however, was too disturbed to yield density estimates representative of the entire sub-class, and P. rubicunda was absent from the low-pole forest, likely as a result of the low availability of the species' preferred foods. This absence in 30% of Sabangau's total area indicates the importance of in situ population surveys at the habitat-specific level for accurately informing conservation strategies. We highlight the conservation value of TPSFs for P. rubicunda given the high population density and large areas remaining, and recommend 1) quantifying the response of P. rubicunda to the logging and burning of its habitats; 2) surveying degraded TPSFs for viable populations, and 3) effectively delineating TPSF sub-class boundaries from remote imagery to facilitate population estimates across the wider peat landscape, given the stark contrast in densities found across the habitat sub-classes of Sabangau. PMID:23526631

  14. Population density of red langurs in Sabangau tropical peat-swamp forest, Central Kalimantan, Indonesia.

    PubMed

    Ehlers Smith, David A; Ehlers Smith, Yvette C

    2013-08-01

    Because of the large-scale destruction of Borneo's rainforests on mineral soils, tropical peat-swamp forests (TPSFs) are increasingly essential for conserving remnant biodiversity, particularly in the lowlands where the majority of habitat conversion has occurred. Consequently, effective strategies for biodiversity conservation are required, which rely on accurate population density and distribution estimates as a baseline. We sought to establish the first population density estimates of the endemic red langur (Presbytis rubicunda) in Sabangau TPSF, the largest remaining contiguous lowland forest-block on Borneo. Using Distance sampling principles, we conducted line transect surveys in two of Sabangau's three principle habitat sub-classes and calculated group density at 2.52 groups km⁻² (95% CI 1.56-4.08) in the mixed-swamp forest sub-class. Based on an average recorded group size of 6.95 individuals, population density was 17.51 ind km⁻², the second highest density recorded in this species. The accessible area of the tall-interior forest, however, was too disturbed to yield density estimates representative of the entire sub-class, and P. rubicunda was absent from the low-pole forest, likely as a result of the low availability of the species' preferred foods. This absence in 30% of Sabangau's total area indicates the importance of in situ population surveys at the habitat-specific level for accurately informing conservation strategies. We highlight the conservation value of TPSFs for P. rubicunda given the high population density and large areas remaining, and recommend 1) quantifying the response of P. rubicunda to the logging and burning of its habitats; 2) surveying degraded TPSFs for viable populations, and 3) effectively delineating TPSF sub-class boundaries from remote imagery to facilitate population estimates across the wider peat landscape, given the stark contrast in densities found across the habitat sub-classes of Sabangau.

  15. Interaction networks and the use of floral resources by male orchid bees (Hymenoptera: Apidae: Euglossini) in a primary rain forests of the Chocó Region (Colombia).

    PubMed

    Ospina-Torres, Rodulfo; Montoya-Pfeiffer, Paula María; Parra-H, Alejandro; Solarte, Victor; Tupac Otero, Joel

    2015-09-01

    Orchid bees are important keystone pollinators from the Neotropics. With the aim to study the relationships between orchid bees and their nectar and aromatic host species, we made systematic samplings of males across two conservation areas in the biogeographic Choc6 Region of Colombia. We used chemical baits to collect 352 male bees during five months. The pollen attached to their bodies was extracted for palynological identification and to estimate interaction networks. The euglossine community consisted of at least 22 species including Eg. maculilabris, Eg. orellana, Eg. championi and Eg. ignita. The male bees were associated with 84 plants but depended on a small group of them (Peperomia spp. and Anthurium spp, as well as species of Solanaceae, Ericaceae and Malpighiaceae) which were widely distributed across the altitudinal gradient, and were available through the year. The resulting interaction networks revealed a typical nested pattern usually found in plant-pollinator interactions, with several rare bee and plant species interaction with a small group of generalist bees and plant species. Albeit, we found variation within networks related to species composition. Such variation may be a consequence of specific differences in plant flowering phenology.

  16. Interaction networks and the use of floral resources by male orchid bees (Hymenoptera: Apidae: Euglossini) in a primary rain forests of the Chocó Region (Colombia).

    PubMed

    Ospina-Torres, Rodulfo; Montoya-Pfeiffer, Paula María; Parra-H, Alejandro; Solarte, Victor; Tupac Otero, Joel

    2015-09-01

    Orchid bees are important keystone pollinators from the Neotropics. With the aim to study the relationships between orchid bees and their nectar and aromatic host species, we made systematic samplings of males across two conservation areas in the biogeographic Choc6 Region of Colombia. We used chemical baits to collect 352 male bees during five months. The pollen attached to their bodies was extracted for palynological identification and to estimate interaction networks. The euglossine community consisted of at least 22 species including Eg. maculilabris, Eg. orellana, Eg. championi and Eg. ignita. The male bees were associated with 84 plants but depended on a small group of them (Peperomia spp. and Anthurium spp, as well as species of Solanaceae, Ericaceae and Malpighiaceae) which were widely distributed across the altitudinal gradient, and were available through the year. The resulting interaction networks revealed a typical nested pattern usually found in plant-pollinator interactions, with several rare bee and plant species interaction with a small group of generalist bees and plant species. Albeit, we found variation within networks related to species composition. Such variation may be a consequence of specific differences in plant flowering phenology. PMID:26666122

  17. Honey Bee Hemocyte Profiling by Flow Cytometry

    PubMed Central

    Marringa, William J.; Krueger, Michael J.; Burritt, Nancy L.; Burritt, James B.

    2014-01-01

    Multiple stress factors in honey bees are causing loss of bee colonies worldwide. Several infectious agents of bees are believed to contribute to this problem. The mechanisms of honey bee immunity are not completely understood, in part due to limited information about the types and abundances of hemocytes that help bees resist disease. Our study utilized flow cytometry and microscopy to examine populations of hemolymph particulates in honey bees. We found bee hemolymph includes permeabilized cells, plasmatocytes, and acellular objects that resemble microparticles, listed in order of increasing abundance. The permeabilized cells and plasmatocytes showed unexpected differences with respect to properties of the plasma membrane and labeling with annexin V. Both permeabilized cells and plasmatocytes failed to show measurable mitochondrial membrane potential by flow cytometry using the JC-1 probe. Our results suggest hemolymph particulate populations are dynamic, revealing significant differences when comparing individual hive members, and when comparing colonies exposed to diverse conditions. Shifts in hemocyte populations in bees likely represent changing conditions or metabolic differences of colony members. A better understanding of hemocyte profiles may provide insight into physiological responses of honey bees to stress factors, some of which may be related to colony failure. PMID:25285798

  18. Using Ecological Niche Models and Niche Analyses to Understand Speciation Patterns: The Case of Sister Neotropical Orchid Bees

    PubMed Central

    Silva, Daniel P.; Vilela, Bruno; De Marco, Paulo; Nemésio, André

    2014-01-01

    The role of past connections between the two major South American forested biomes on current species distribution has been recognized a long time ago. Climatic oscillations that further separated these biomes have promoted parapatric speciation, in which many species had their continuous distribution split, giving rise to different but related species (i.e., different potential distributions and realized niche features). The distribution of many sister species of orchid bees follow this pattern. Here, using ecological niche models and niche analyses, we (1) tested the role of ecological niche differentiation on the divergence between sister orchid-bees (genera Eulaema and Eufriesea) from the Amazon and Atlantic forests, and (2) highlighted interesting areas for new surveys. Amazonian species occupied different realized niches than their Atlantic sister species. Conversely, species of sympatric but distantly related Eulaema bees occupied similar realized niches. Amazonian species had a wide potential distribution in South America, whereas Atlantic Forest species were more limited to the eastern coast of the continent. Additionally, we identified several areas in need of future surveys. Our results show that the realized niche of Atlantic-Amazonian sister species of orchid bees, which have been previously treated as allopatric populations of three species, had limited niche overlap and similarity. These findings agree with their current taxonomy, which treats each of those populations as distinct valid species. PMID:25422941

  19. Genetic diversity of Forest and Savannah chicken populations of Ghana as estimated by microsatellite markers.

    PubMed

    Osei-Amponsah, Richard; Kayang, Boniface B; Naazie, Augustine; Osei, Yaa D; Youssao, Issaka A K; Yapi-Gnaore, Valentine C; Tixier-Boichard, Michèle; Rognon, Xavier

    2010-06-01

    The characterization of indigenous animal genetic resources is a requisite step in providing needed information for the conservation of useful genotypes against future needs. Thus, in this study, 22 microsatellite markers were used to genotype 114 local chickens from the Forest (n = 59) and Savannah (n = 55) eco-zones of Ghana and the results compared to those of the ancestral red junglefowl (n = 15) and two European commercial chicken populations--a broiler (n = 25) and white leghorn (n = 25). A total of 171 alleles were observed, with an average of 7.8 alleles per locus. The local Ghanaian chickens showed higher diversity in terms of the observed number of alleles per locus (6.6) and observed heterozygosity (0.568) compared with the combined control populations (6.0 and 0.458, respectively). However, Wright's F-statistics revealed negligible genetic differentiation (F(ST)) in local Ghanaian chicken populations. In addition, 65% of the Savannah chickens were inferred to be more likely from the Forest, suggesting a south-north dispersal of chickens from their probable original location in the Forest zone to the Savannah areas. It is concluded that the Forest and Savannah chickens of Ghana are a single, randomly mating unselected population, characterized by high genetic diversity and constitute a valuable resource for conservation and improvement. PMID:20597885

  20. Population dynamics of Eleutherodactylus coqui in cordillera forest reserves of Puerto Rico

    USGS Publications Warehouse

    Fogarty, J.H.; Vilella, F.J.

    2002-01-01

    Various aspects of population structure and dynamics of Eleutherodactylus coqui in two forest reserves (Maricao and Guilarte) of the central mountain range of Puerto Rico were determined between July 1997 and June 1998. Adult density ranged from 8-25 animals/100 m2 for the wet season and 3-19 animals/100 m2 for the dry season. Abundance of froglets and juveniles was also greater in the wet season compared to the dry season. By contrast, egg mass counts were greater in the dry season compared to the wet season. Adult body size increased from wet to dry season as population density declined and was found to differ significantly between forests. Adult E. coqui trapped at similar elevations were larger in Guilarte compared to those in Maricao. Average body size for Maricao and Guilarte populations were smaller than those reported for populations in eastern Puerto Rico. Comparing average snout-vent length among frogs from the Luquillo Mountains, Guilarte Forest, and Maricao Forest, a gradient of decreasing body size was observed from east to west across the island.

  1. Effects of DDT on bird population of scrub forest

    USGS Publications Warehouse

    Robbins, C.S.; Stewart, R.E.

    1949-01-01

    An oil spray of DDT was applied at the rate of five pounds per acre to a 90-acre tract of 5-year-old scrub and sapling growth at Beltsville, Maryland. Bird population studies were carried on in a 30-acre plot at the center of the sprayed area, and in a 30-acre check area of the same habitat one-half mile away. Of the five commonest species in the sprayed area, the Maryland yellowthroat, prairie warbler, and house wren were reduced 80 per cent, and the red-eyed towhee was apparently reduced 35 per cent; while no appreciable change in the numbers of yellow-breasted chats was noted. The total decrease for the five commonest species, which represented 77 per cent of the original population, was 65 per cent.

  2. Bee Stings & Their Consequences.

    ERIC Educational Resources Information Center

    Rupp, Robert M.

    1991-01-01

    Relevant information concerning bee stings is provided. Possible reactions to a bee sting and their symptoms, components of bee venom, diagnosis of hypersensitivity, and bee sting prevention and treatment are topics of discussion. The possibility of bee stings occurring during field trips and the required precautions are discussed. (KR)

  3. Bee Weekend.

    ERIC Educational Resources Information Center

    Beidler, Peter G.

    1987-01-01

    Recounts weekend at a bee farm, an activity for a required Lehigh University freshman English composition course designed to facilitate socialization and exchange of ideas and to provide experiences for students to write about. Uses excerpts from journals of nine students. (NEC)

  4. Kelp forest fish populations in marine reserves and adjacent exploited areas of central California

    USGS Publications Warehouse

    Paddack, M.J.; Estes, J.A.

    2000-01-01

    Population structure (density and size distribution) of 10 species of epibenthic kelp forest fishes was compared between three marine reserves and adjacent exploited areas in central California. We also contrasted substrate relief, algal turf cover, and kelp population density among these areas. Densities of fishes were 12-35% greater within the reserves, but this difference was not statistically) significant. Habitat features explained only 4% of the variation in fish density and did not vary consistently between reserves and nonreserves. The average length of rockfish (genus Sebastes) was significantly greater in two of the three reserve sites, as was the proportion of larger fish. Population density and size differences combined to produce substantially greater biomass and, therefore, greater reproductive potential per unit of area within the reserves. The magnitude of these effects seems to be influenced by the reserve's age. Our findings demonstrate that current levels of fishing pressure influence kelp forest rockfish populations and suggest that this effect is widespread in central California. Existing marine reserves in central California kelp forests may help sustain exploited populations both through adult emigration and larval pool augmentation. The magnitude of these effects remains uncertain, however, because the spatial scale of both larval and adult dispersal relative to the size of existing reserves is unknown.

  5. A Measure of the Forest Protected Areas Benefits for the Surrounding Population: A Case Study of the Bouaflé Protected Forest (CÔTE D'IVOIRE)

    NASA Astrophysics Data System (ADS)

    Kouame, B. N. P.

    2015-12-01

    Côte d'Ivoire located in West Africa, registers high level of biodiversity which occurs mainly in forest land. The country has suffered severe deforestation. However, deforestation and forest degradation release Greenhouse Gases into the atmosphere which contributes to Climate Change. In order to address the deforestation, many actions are taken, one of which is the implementation of protected areas within countries. These measures put restrictions on the access of local communities to forest services. However, local communities supplement their daily livelihood from forests, especially from timber and non-timber forest products. What are the effects of forests conservation in protected areas on surrounding population? This study focuses on the Bouaflé protected forest (foret classée de Bouaflé) in the western part of Côte d'Ivoire. The forest is 20350 ha and was made a protected forest in 1974. It is one of the most deforested protected areas in the country. Firstly, we described the perception of forest benefits by the population. Secondly, we estimated the benefits of forest conservation using a contingent valuation approach, particularly the Willingness to Pay (WTP) methodology. From our sample size of 156 households, it appears that most of the individuals are aware of the importance of the forest (94 % against 6%). According to the estimate of the benefits, it results on average, people are willing to pay 1658.491F CFA (2.53 Euros). The median WTP is 1000 FCFA. This study will be helpful by adding to the scientific literature and for inducing local people implication in conservation.

  6. Colonies of Bumble Bees (Bombus impatiens) Produce Fewer Workers, Less Bee Biomass, and Have Smaller Mother Queens Following Fungicide Exposure.

    PubMed

    Bernauer, Olivia M; Gaines-Day, Hannah R; Steffan, Shawn A

    2015-06-01

    Bees provide vital pollination services to the majority of flowering plants in both natural and agricultural systems. Unfortunately, both native and managed bee populations are experiencing declines, threatening the persistence of these plants and crops. Agricultural chemicals are one possible culprit contributing to bee declines. Even fungicides, generally considered safe for bees, have been shown to disrupt honey bee development and impair bumble bee behavior. Little is known, however, how fungicides may affect bumble bee colony growth. We conducted a controlled cage study to determine the effects of fungicide exposure on colonies of a native bumble bee species (Bombus impatiens). Colonies of B. impatiens were exposed to flowers treated with field-relevant levels of the fungicide chlorothalonil over the course of one month. Colony success was assessed by the number and biomass of larvae, pupae, and adult bumble bees. Bumble bee colonies exposed to fungicide produced fewer workers, lower total bee biomass, and had lighter mother queens than control colonies. Our results suggest that fungicides negatively affect the colony success of a native bumble bee species and that the use of fungicides during bloom has the potential to severely impact the success of native bumble bee populations foraging in agroecosystems.

  7. Colonies of Bumble Bees (Bombus impatiens) Produce Fewer Workers, Less Bee Biomass, and Have Smaller Mother Queens Following Fungicide Exposure.

    PubMed

    Bernauer, Olivia M; Gaines-Day, Hannah R; Steffan, Shawn A

    2015-01-01

    Bees provide vital pollination services to the majority of flowering plants in both natural and agricultural systems. Unfortunately, both native and managed bee populations are experiencing declines, threatening the persistence of these plants and crops. Agricultural chemicals are one possible culprit contributing to bee declines. Even fungicides, generally considered safe for bees, have been shown to disrupt honey bee development and impair bumble bee behavior. Little is known, however, how fungicides may affect bumble bee colony growth. We conducted a controlled cage study to determine the effects of fungicide exposure on colonies of a native bumble bee species (Bombus impatiens). Colonies of B. impatiens were exposed to flowers treated with field-relevant levels of the fungicide chlorothalonil over the course of one month. Colony success was assessed by the number and biomass of larvae, pupae, and adult bumble bees. Bumble bee colonies exposed to fungicide produced fewer workers, lower total bee biomass, and had lighter mother queens than control colonies. Our results suggest that fungicides negatively affect the colony success of a native bumble bee species and that the use of fungicides during bloom has the potential to severely impact the success of native bumble bee populations foraging in agroecosystems. PMID:26463198

  8. Colonies of Bumble Bees (Bombus impatiens) Produce Fewer Workers, Less Bee Biomass, and Have Smaller Mother Queens Following Fungicide Exposure

    PubMed Central

    Bernauer, Olivia M.; Gaines-Day, Hannah R.; Steffan, Shawn A.

    2015-01-01

    Bees provide vital pollination services to the majority of flowering plants in both natural and agricultural systems. Unfortunately, both native and managed bee populations are experiencing declines, threatening the persistence of these plants and crops. Agricultural chemicals are one possible culprit contributing to bee declines. Even fungicides, generally considered safe for bees, have been shown to disrupt honey bee development and impair bumble bee behavior. Little is known, however, how fungicides may affect bumble bee colony growth. We conducted a controlled cage study to determine the effects of fungicide exposure on colonies of a native bumble bee species (Bombus impatiens). Colonies of B. impatiens were exposed to flowers treated with field-relevant levels of the fungicide chlorothalonil over the course of one month. Colony success was assessed by the number and biomass of larvae, pupae, and adult bumble bees. Bumble bee colonies exposed to fungicide produced fewer workers, lower total bee biomass, and had lighter mother queens than control colonies. Our results suggest that fungicides negatively affect the colony success of a native bumble bee species and that the use of fungicides during bloom has the potential to severely impact the success of native bumble bee populations foraging in agroecosystems. PMID:26463198

  9. Environmental change and disease dynamics: effects of intensive forest management on Puumala hantavirus infection in boreal bank vole populations.

    PubMed

    Voutilainen, Liina; Savola, Sakeri; Kallio, Eva Riikka; Laakkonen, Juha; Vaheri, Antti; Vapalahti, Olli; Henttonen, Heikki

    2012-01-01

    Intensive management of Fennoscandian forests has led to a mosaic of woodlands in different stages of maturity. The main rodent host of the zoonotic Puumala hantavirus (PUUV) is the bank vole (Myodes glareolus), a species that can be found in all woodlands and especially mature forests. We investigated the influence of forest age structure on PUUV infection dynamics in bank voles. Over four years, we trapped small mammals twice a year in a forest network of different succession stages in Northern Finland. Our study sites represented four forest age classes from young (4 to 30 years) to mature (over 100 years) forests. We show that PUUV-infected bank voles occurred commonly in all forest age classes, but peaked in mature forests. The probability of an individual bank vole to be PUUV infected was positively related to concurrent host population density. However, when population density was controlled for, a relatively higher infection rate was observed in voles trapped in younger forests. Furthermore, we found evidence of a "dilution effect" in that the infection probability was negatively associated with the simultaneous density of other small mammals during the breeding season. Our results suggest that younger forests created by intensive management can reduce hantaviral load in the environment, but PUUV is common in woodlands of all ages. As such, the Fennoscandian forest landscape represents a significant reservoir and source of hantaviral infection in humans.

  10. Forest succession and population viability of grassland plants: long repayment of extinction debt in Primula veris.

    PubMed

    Lehtilä, Kari; Dahlgren, Johan P; Garcia, Maria Begoña; Leimu, Roosa; Syrjänen, Kimmo; Ehrlén, Johan

    2016-05-01

    Time lags in responses of organisms to deteriorating environmental conditions delay population declines and extinctions. We examined how local processes at the population level contribute to extinction debt, and how cycles of habitat deterioration and recovery may delay extinction. We carried out a demographic analysis of the fate of the grassland perennial Primula veris after the cessation of grassland management, where we used either a unidirectional succession model for forest habitat or a rotation model with a period of forest growth followed by a clear-cut and a new successional cycle. The simulations indicated that P. veris populations may have an extinction time of decades to centuries after a detrimental management change. A survey of the current incidence and abundance of P. veris in sites with different histories of afforestation confirmed the simulation results of low extinction rates. P. veris had reduced incidence and abundance only at sites with at least 100 years of forest cover. Time to extinction in simulations was dependent on the duration of the periods with favourable and unfavourable conditions after management cessation, and the population sizes and growth rates in these periods. Our results thus suggest that the ability of a species to survive is a complex function of disturbance regimes, rates of successional change, and the demographic response to environmental changes. Detailed demographic studies over entire successional cycles are therefore essential to identify the environmental conditions that enable long-term persistence and to design management for species experiencing extinction debts.

  11. Comparative Population Genomics of African Montane Forest Mammals Support Population Persistence across a Climatic Gradient and Quaternary Climatic Cycles.

    PubMed

    Demos, Terrence C; Kerbis Peterhans, Julian C; Joseph, Tyler A; Robinson, John D; Agwanda, Bernard; Hickerson, Michael J

    2015-01-01

    The Eastern Afromontane biodiversity hotspot (EABH) has the highest concentration of biodiversity in tropical Africa, yet few studies have investigated recent historical diversification processes in EABH lineages. Herein, we analyze restriction-site associated DNA-sequences (RAD-Seq) to study recent historical processes in co-distributed mouse (Hylomyscus) and shrew (Sylvisorex) species complexes, with an aim to better determine how historical paleoenvironmental processes might have contributed to the EABH's high diversity. We analyzed complete SNP matrices of > 50,000 RAD loci to delineate populations, reconstruct the history of isolation and admixture, and discover geographic patterns of genetic partitioning. These analyses demonstrate that persistently unsuitable habitat may have isolated multiple populations distributed across montane habitat islands in the Itombwe Massif and Albertine Rift to the west as well as Mt Elgon and Kenyan Highlands to the east. We detected low genetic diversity in Kenyan Highland populations of both genera, consistent with smaller historical population sizes in this region. We additionally tested predictions that Albertine Rift populations are older and more persistently isolated compared to the Kenyan Highlands. Phylogenetic analyses support greater historical isolation among Albertine Rift populations of both shrews and mice compared to the Kenyan Highlands and suggest that there are genetically isolated populations from both focal genera in the Itombwe Massif, Democratic Republic of Congo. The Albertine Rift ecoregion has the highest mammalian tropical forest species richness per unit area on earth. Our results clearly support accelerating efforts to conserve this diversity. PMID:26394036

  12. Comparative Population Genomics of African Montane Forest Mammals Support Population Persistence across a Climatic Gradient and Quaternary Climatic Cycles.

    PubMed

    Demos, Terrence C; Kerbis Peterhans, Julian C; Joseph, Tyler A; Robinson, John D; Agwanda, Bernard; Hickerson, Michael J

    2015-01-01

    The Eastern Afromontane biodiversity hotspot (EABH) has the highest concentration of biodiversity in tropical Africa, yet few studies have investigated recent historical diversification processes in EABH lineages. Herein, we analyze restriction-site associated DNA-sequences (RAD-Seq) to study recent historical processes in co-distributed mouse (Hylomyscus) and shrew (Sylvisorex) species complexes, with an aim to better determine how historical paleoenvironmental processes might have contributed to the EABH's high diversity. We analyzed complete SNP matrices of > 50,000 RAD loci to delineate populations, reconstruct the history of isolation and admixture, and discover geographic patterns of genetic partitioning. These analyses demonstrate that persistently unsuitable habitat may have isolated multiple populations distributed across montane habitat islands in the Itombwe Massif and Albertine Rift to the west as well as Mt Elgon and Kenyan Highlands to the east. We detected low genetic diversity in Kenyan Highland populations of both genera, consistent with smaller historical population sizes in this region. We additionally tested predictions that Albertine Rift populations are older and more persistently isolated compared to the Kenyan Highlands. Phylogenetic analyses support greater historical isolation among Albertine Rift populations of both shrews and mice compared to the Kenyan Highlands and suggest that there are genetically isolated populations from both focal genera in the Itombwe Massif, Democratic Republic of Congo. The Albertine Rift ecoregion has the highest mammalian tropical forest species richness per unit area on earth. Our results clearly support accelerating efforts to conserve this diversity.

  13. Comparative Population Genomics of African Montane Forest Mammals Support Population Persistence across a Climatic Gradient and Quaternary Climatic Cycles

    PubMed Central

    Demos, Terrence C.; Kerbis Peterhans, Julian C.; Joseph, Tyler A.; Robinson, John D.; Agwanda, Bernard; Hickerson, Michael J.

    2015-01-01

    The Eastern Afromontane biodiversity hotspot (EABH) has the highest concentration of biodiversity in tropical Africa, yet few studies have investigated recent historical diversification processes in EABH lineages. Herein, we analyze restriction-site associated DNA-sequences (RAD-Seq) to study recent historical processes in co-distributed mouse (Hylomyscus) and shrew (Sylvisorex) species complexes, with an aim to better determine how historical paleoenvironmental processes might have contributed to the EABH’s high diversity. We analyzed complete SNP matrices of > 50,000 RAD loci to delineate populations, reconstruct the history of isolation and admixture, and discover geographic patterns of genetic partitioning. These analyses demonstrate that persistently unsuitable habitat may have isolated multiple populations distributed across montane habitat islands in the Itombwe Massif and Albertine Rift to the west as well as Mt Elgon and Kenyan Highlands to the east. We detected low genetic diversity in Kenyan Highland populations of both genera, consistent with smaller historical population sizes in this region. We additionally tested predictions that Albertine Rift populations are older and more persistently isolated compared to the Kenyan Highlands. Phylogenetic analyses support greater historical isolation among Albertine Rift populations of both shrews and mice compared to the Kenyan Highlands and suggest that there are genetically isolated populations from both focal genera in the Itombwe Massif, Democratic Republic of Congo. The Albertine Rift ecoregion has the highest mammalian tropical forest species richness per unit area on earth. Our results clearly support accelerating efforts to conserve this diversity. PMID:26394036

  14. Long-term effects of timber harvesting on hemicellulolytic microbial populations in coniferous forest soils.

    PubMed

    Leung, Hilary T C; Maas, Kendra R; Wilhelm, Roland C; Mohn, William W

    2016-02-01

    Forest ecosystems need to be sustainably managed, as they are major reservoirs of biodiversity, provide important economic resources and modulate global climate. We have a poor knowledge of populations responsible for key biomass degradation processes in forest soils and the effects of forest harvesting on these populations. Here, we investigated the effects of three timber-harvesting methods, varying in the degree of organic matter removal, on putatively hemicellulolytic bacterial and fungal populations 10 or more years after harvesting and replanting. We used stable-isotope probing to identify populations that incorporated (13)C from labeled hemicellulose, analyzing (13)C-enriched phospholipid fatty acids, bacterial 16 S rRNA genes and fungal ITS regions. In soil microcosms, we identified 104 bacterial and 52 fungal hemicellulolytic operational taxonomic units (OTUs). Several of these OTUs are affiliated with taxa not previously reported to degrade hemicellulose, including the bacterial genera Methylibium, Pelomonas and Rhodoferax, and the fungal genera Cladosporium, Pseudeurotiaceae, Capronia, Xenopolyscytalum and Venturia. The effect of harvesting on hemicellulolytic populations was evaluated based on in situ bacterial and fungal OTUs. Harvesting treatments had significant but modest long-term effects on relative abundances of hemicellulolytic populations, which differed in strength between two ecozones and between soil layers. For soils incubated in microcosms, prior harvesting treatments did not affect the rate of incorporation of hemicellulose carbon into microbial biomass. In six ecozones across North America, distributions of the bacterial hemicellulolytic OTUs were similar, whereas distributions of fungal ones differed. Our work demonstrates that diverse taxa in soil are hemicellulolytic, many of which are differentially affected by the impact of harvesting on environmental conditions. However, the hemicellulolytic capacity of soil communities appears

  15. Long-term effects of timber harvesting on hemicellulolytic microbial populations in coniferous forest soils.

    PubMed

    Leung, Hilary T C; Maas, Kendra R; Wilhelm, Roland C; Mohn, William W

    2016-02-01

    Forest ecosystems need to be sustainably managed, as they are major reservoirs of biodiversity, provide important economic resources and modulate global climate. We have a poor knowledge of populations responsible for key biomass degradation processes in forest soils and the effects of forest harvesting on these populations. Here, we investigated the effects of three timber-harvesting methods, varying in the degree of organic matter removal, on putatively hemicellulolytic bacterial and fungal populations 10 or more years after harvesting and replanting. We used stable-isotope probing to identify populations that incorporated (13)C from labeled hemicellulose, analyzing (13)C-enriched phospholipid fatty acids, bacterial 16 S rRNA genes and fungal ITS regions. In soil microcosms, we identified 104 bacterial and 52 fungal hemicellulolytic operational taxonomic units (OTUs). Several of these OTUs are affiliated with taxa not previously reported to degrade hemicellulose, including the bacterial genera Methylibium, Pelomonas and Rhodoferax, and the fungal genera Cladosporium, Pseudeurotiaceae, Capronia, Xenopolyscytalum and Venturia. The effect of harvesting on hemicellulolytic populations was evaluated based on in situ bacterial and fungal OTUs. Harvesting treatments had significant but modest long-term effects on relative abundances of hemicellulolytic populations, which differed in strength between two ecozones and between soil layers. For soils incubated in microcosms, prior harvesting treatments did not affect the rate of incorporation of hemicellulose carbon into microbial biomass. In six ecozones across North America, distributions of the bacterial hemicellulolytic OTUs were similar, whereas distributions of fungal ones differed. Our work demonstrates that diverse taxa in soil are hemicellulolytic, many of which are differentially affected by the impact of harvesting on environmental conditions. However, the hemicellulolytic capacity of soil communities appears

  16. Waterfowl populations are resilient to immediate and lagged impacts of wildfires in the boreal forest

    USGS Publications Warehouse

    Lewis, Tyler; Schmutz, Joel A.; Amundson, Courtney L.; Lindberg, Mark S.

    2016-01-01

    Summary 1. Wildfires are the principal disturbance in the boreal forest, and their size and frequency are increasing as the climate warms. Impacts of fires on boreal wildlife are largely unknown, especially for the tens of millions of waterfowl that breed in the region. This knowledge gap creates significant barriers to the integrative management of fires and waterfowl, leading to fire policies that largely disregard waterfowl. 2. Waterfowl populations across the western boreal forest of North America have been monitored annually since 1955 by the Waterfowl Breeding Population and Habitat Survey (BPOP), widely considered the most extensive wildlife survey in the world. Using these data, we examined impacts of forest fires on abundance of two waterfowl guilds – dabblers and divers. We modelled waterfowl abundance in relation to fire extent (i.e. amount of survey transect burned) and time since fire, examining both immediate and lagged fire impacts. 3. From 1955 to 2014, >1100 fires in the western boreal forest intersected BPOP survey transects, and many transects burned multiple times. Nonetheless, fires had no detectable impact on waterfowl abundance; annual transect counts of dabbler and diver pairs remained stable from the pre- to post-fire period. 4. The absence of fire impacts on waterfowl abundance extended from the years immediately following the fire to those more than a decade afterwards. Likewise, the amount of transect burned did not influence waterfowl abundance, with similar pair counts from the pre- to post-fire period for small (1–20% burned), medium (21–60%) and large (>60%) burns. 5. Policy implications. Waterfowl populations appear largely resilient to forest fires, providing initial evidence that current policies of limited fire suppression, which predominate throughout much of the boreal forest, have not been detrimental to waterfowl populations. Likewise, fire-related management actions, such as prescribed burning or targeted suppression

  17. Impact of industrial contamination on the populations of small forest rodents.

    PubMed

    Ivanter, E V; Medvedev, N V

    2015-01-01

    Investigations performed for monitoring the impact of industrial contamination from the Kostomuksha ore mining and processing enterprise (northern Karelia) on the populations of forest mouse-like rodents revealed increased embryonic mortality (three to four times higher compared to the control) in breeding females from the areas contaminated by nitrogen and sulfur oxides within the territory studied. The toxicants also influence other parameters of the population: abundance dynamics, ecological and spatial structure of the population, and reproduction rates. The results demonstrate that the population reactions of species may turn out to be more accurate and demonstrative when estimating the consequences of industrial contamination than the direct concentrations of a particular toxicant in the animal body.

  18. Impact of industrial contamination on the populations of small forest rodents.

    PubMed

    Ivanter, E V; Medvedev, N V

    2015-01-01

    Investigations performed for monitoring the impact of industrial contamination from the Kostomuksha ore mining and processing enterprise (northern Karelia) on the populations of forest mouse-like rodents revealed increased embryonic mortality (three to four times higher compared to the control) in breeding females from the areas contaminated by nitrogen and sulfur oxides within the territory studied. The toxicants also influence other parameters of the population: abundance dynamics, ecological and spatial structure of the population, and reproduction rates. The results demonstrate that the population reactions of species may turn out to be more accurate and demonstrative when estimating the consequences of industrial contamination than the direct concentrations of a particular toxicant in the animal body. PMID:26530070

  19. 'Bee hotels' as tools for native pollinator conservation: a premature verdict?

    PubMed

    MacIvor, J Scott; Packer, Laurence

    2015-01-01

    Society is increasingly concerned with declining wild bee populations. Although most bees nest in the ground, considerable effort has centered on installing 'bee hotels'--also known as nest boxes or trap nests--which artificially aggregate nest sites of above ground nesting bees. Campaigns to 'save the bees' often promote these devices despite the absence of data indicating they have a positive effect. From a survey of almost 600 bee hotels set up over a period of three years in Toronto, Canada, introduced bees nested at 32.9% of sites and represented 24.6% of more than 27,000 total bees and wasps recorded (47.1% of all bees recorded). Native bees were parasitized more than introduced bees and females of introduced bee species provisioned nests with significantly more female larva each year. Native wasps were significantly more abundant than both native and introduced bees and occupied almost 3/4 of all bee hotels each year; further, introduced wasps were the only group to significantly increase in relative abundance year over year. More research is needed to elucidate the potential pitfalls and benefits of using bee hotels in the conservation and population dynamics of wild native bees. PMID:25785609

  20. 'Bee hotels' as tools for native pollinator conservation: a premature verdict?

    PubMed

    MacIvor, J Scott; Packer, Laurence

    2015-01-01

    Society is increasingly concerned with declining wild bee populations. Although most bees nest in the ground, considerable effort has centered on installing 'bee hotels'--also known as nest boxes or trap nests--which artificially aggregate nest sites of above ground nesting bees. Campaigns to 'save the bees' often promote these devices despite the absence of data indicating they have a positive effect. From a survey of almost 600 bee hotels set up over a period of three years in Toronto, Canada, introduced bees nested at 32.9% of sites and represented 24.6% of more than 27,000 total bees and wasps recorded (47.1% of all bees recorded). Native bees were parasitized more than introduced bees and females of introduced bee species provisioned nests with significantly more female larva each year. Native wasps were significantly more abundant than both native and introduced bees and occupied almost 3/4 of all bee hotels each year; further, introduced wasps were the only group to significantly increase in relative abundance year over year. More research is needed to elucidate the potential pitfalls and benefits of using bee hotels in the conservation and population dynamics of wild native bees.

  1. Cryptic species, native populations and biological invasions by a eucalypt forest pathogen.

    PubMed

    Pérez, Guillermo; Slippers, Bernard; Wingfield, Michael J; Wingfield, Brenda D; Carnegie, Angus J; Burgess, Treena I

    2012-09-01

    Human-associated introduction of pathogens and consequent invasions is very evident in areas where no related organisms existed before. In areas where related but distinct populations or closely related cryptic species already exist, the invasion process is much harder to unravel. In this study, the population structure of the Eucalyptus leaf pathogen Teratosphaeria nubilosa was studied within its native range in Australia, including both commercial plantations and native forests. A collection of 521 isolates from across its distribution was characterized using eight microsatellite loci, resulting in 112 multilocus haplotypes (MLHs). Multivariate and Bayesian analyses of the population conducted in structure revealed three genetically isolated groups (A, B and C), with no evidence for recombination or hybridization among groups, even when they co-occur in the same plantation. DNA sequence data of the ITS (n = 32), β-tubulin (n = 32) and 27 anonymous loci (n = 16) were consistent with microsatellite data in suggesting that T. nubilosa should be considered as a species complex. Patterns of genetic diversity provided evidence of biological invasions by the pathogen within Australia in the states of Western Australia and New South Wales and helped unravel the pattern of invasion beyond Australia into New Zealand, Brazil and Uruguay. No significant genetic differences in pathogen populations collected in native forests and commercial plantations were observed. This emphasizes the importance of sanitation in the acquisition of nursery stock for the establishment of commercial plantations.

  2. Non-bee insects are important contributors to global crop pollination

    PubMed Central

    Bartomeus, Ignasi; Garibaldi, Lucas A.; Garratt, Michael P. D.; Howlett, Brad G.; Winfree, Rachael; Cunningham, Saul A.; Mayfield, Margaret M.; Arthur, Anthony D.; Andersson, Georg K. S.; Bommarco, Riccardo; Brittain, Claire; Carvalheiro, Luísa G.; Chacoff, Natacha P.; Entling, Martin H.; Foully, Benjamin; Freitas, Breno M.; Gemmill-Herren, Barbara; Ghazoul, Jaboury; Griffin, Sean R.; Gross, Caroline L.; Herbertsson, Lina; Herzog, Felix; Hipólito, Juliana; Jaggar, Sue; Jauker, Frank; Klein, Alexandra-Maria; Kleijn, David; Krishnan, Smitha; Lemos, Camila Q.; Lindström, Sandra A. M.; Mandelik, Yael; Monteiro, Victor M.; Nelson, Warrick; Nilsson, Lovisa; Pattemore, David E.; de O. Pereira, Natália; Pisanty, Gideon; Potts, Simon G.; Reemer, Menno; Rundlöf, Maj; Sheffield, Cory S.; Scheper, Jeroen; Schüepp, Christof; Smith, Henrik G.; Stanley, Dara A.; Stout, Jane C.; Szentgyörgyi, Hajnalka; Taki, Hisatomo; Vergara, Carlos H.; Viana, Blandina F.; Woyciechowski, Michal

    2016-01-01

    Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25–50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines. PMID:26621730

  3. Non-bee insects are important contributors to global crop pollination.

    PubMed

    Rader, Romina; Bartomeus, Ignasi; Garibaldi, Lucas A; Garratt, Michael P D; Howlett, Brad G; Winfree, Rachael; Cunningham, Saul A; Mayfield, Margaret M; Arthur, Anthony D; Andersson, Georg K S; Bommarco, Riccardo; Brittain, Claire; Carvalheiro, Luísa G; Chacoff, Natacha P; Entling, Martin H; Foully, Benjamin; Freitas, Breno M; Gemmill-Herren, Barbara; Ghazoul, Jaboury; Griffin, Sean R; Gross, Caroline L; Herbertsson, Lina; Herzog, Felix; Hipólito, Juliana; Jaggar, Sue; Jauker, Frank; Klein, Alexandra-Maria; Kleijn, David; Krishnan, Smitha; Lemos, Camila Q; Lindström, Sandra A M; Mandelik, Yael; Monteiro, Victor M; Nelson, Warrick; Nilsson, Lovisa; Pattemore, David E; Pereira, Natália de O; Pisanty, Gideon; Potts, Simon G; Reemer, Menno; Rundlöf, Maj; Sheffield, Cory S; Scheper, Jeroen; Schüepp, Christof; Smith, Henrik G; Stanley, Dara A; Stout, Jane C; Szentgyörgyi, Hajnalka; Taki, Hisatomo; Vergara, Carlos H; Viana, Blandina F; Woyciechowski, Michal

    2016-01-01

    Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25-50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines.

  4. Non-bee insects are important contributors to global crop pollination.

    PubMed

    Rader, Romina; Bartomeus, Ignasi; Garibaldi, Lucas A; Garratt, Michael P D; Howlett, Brad G; Winfree, Rachael; Cunningham, Saul A; Mayfield, Margaret M; Arthur, Anthony D; Andersson, Georg K S; Bommarco, Riccardo; Brittain, Claire; Carvalheiro, Luísa G; Chacoff, Natacha P; Entling, Martin H; Foully, Benjamin; Freitas, Breno M; Gemmill-Herren, Barbara; Ghazoul, Jaboury; Griffin, Sean R; Gross, Caroline L; Herbertsson, Lina; Herzog, Felix; Hipólito, Juliana; Jaggar, Sue; Jauker, Frank; Klein, Alexandra-Maria; Kleijn, David; Krishnan, Smitha; Lemos, Camila Q; Lindström, Sandra A M; Mandelik, Yael; Monteiro, Victor M; Nelson, Warrick; Nilsson, Lovisa; Pattemore, David E; Pereira, Natália de O; Pisanty, Gideon; Potts, Simon G; Reemer, Menno; Rundlöf, Maj; Sheffield, Cory S; Scheper, Jeroen; Schüepp, Christof; Smith, Henrik G; Stanley, Dara A; Stout, Jane C; Szentgyörgyi, Hajnalka; Taki, Hisatomo; Vergara, Carlos H; Viana, Blandina F; Woyciechowski, Michal

    2016-01-01

    Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25-50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines. PMID:26621730

  5. Infra-population and -community dynamics of the parasites Nosema apis and Nosema ceranae, and consequences for honey bee (Apis mellifera) hosts.

    PubMed

    Williams, Geoffrey R; Shutler, Dave; Burgher-MacLellan, Karen L; Rogers, Richard E L

    2014-01-01

    Nosema spp. fungal gut parasites are among myriad possible explanations for contemporary increased mortality of western honey bees (Apis mellifera, hereafter honey bee) in many regions of the world. Invasive Nosema ceranae is particularly worrisome because some evidence suggests it has greater virulence than its congener N. apis. N. ceranae appears to have recently switched hosts from Asian honey bees (Apis cerana) and now has a nearly global distribution in honey bees, apparently displacing N. apis. We examined parasite reproduction and effects of N. apis, N. ceranae, and mixed Nosema infections on honey bee hosts in laboratory experiments. Both infection intensity and honey bee mortality were significantly greater for N. ceranae than for N. apis or mixed infections; mixed infection resulted in mortality similar to N. apis parasitism and reduced spore intensity, possibly due to inter-specific competition. This is the first long-term laboratory study to demonstrate lethal consequences of N. apis and N. ceranae and mixed Nosema parasitism in honey bees, and suggests that differences in reproduction and intra-host competition may explain apparent heterogeneous exclusion of the historic parasite by the invasive species. PMID:24987989

  6. Infra-population and -community dynamics of the parasites Nosema apis and Nosema ceranae, and consequences for honey bee (Apis mellifera) hosts.

    PubMed

    Williams, Geoffrey R; Shutler, Dave; Burgher-MacLellan, Karen L; Rogers, Richard E L

    2014-01-01

    Nosema spp. fungal gut parasites are among myriad possible explanations for contemporary increased mortality of western honey bees (Apis mellifera, hereafter honey bee) in many regions of the world. Invasive Nosema ceranae is particularly worrisome because some evidence suggests it has greater virulence than its congener N. apis. N. ceranae appears to have recently switched hosts from Asian honey bees (Apis cerana) and now has a nearly global distribution in honey bees, apparently displacing N. apis. We examined parasite reproduction and effects of N. apis, N. ceranae, and mixed Nosema infections on honey bee hosts in laboratory experiments. Both infection intensity and honey bee mortality were significantly greater for N. ceranae than for N. apis or mixed infections; mixed infection resulted in mortality similar to N. apis parasitism and reduced spore intensity, possibly due to inter-specific competition. This is the first long-term laboratory study to demonstrate lethal consequences of N. apis and N. ceranae and mixed Nosema parasitism in honey bees, and suggests that differences in reproduction and intra-host competition may explain apparent heterogeneous exclusion of the historic parasite by the invasive species.

  7. The plight of the bees

    USGS Publications Warehouse

    Spivak, M.; Mader, E.; Vaughan, M.; Euliss, N.H.

    2011-01-01

    The loss of biodiversity is a trend that is garnering much concern. As organisms have evolved mutualistic and synergistic relationships, the loss of one or a few species can have a much wider environmental impact. Since much pollination is facilitated by bees, the reported colony collapse disorder has many worried of widespread agricultural fallout and thus deleterious impact on human foodstocks. In this Feature, Spivak et al. review what is known of the present state of bee populations and provide information on how to mitigate and reverse the trend. ?? 2010 American Chemical Society.

  8. Monitoring population and land use change in tropical forest protected areas

    NASA Astrophysics Data System (ADS)

    Zvoleff, A. I.; Rosa, M.; Ahumada, J. A.

    2014-12-01

    Monitoring human-environment interactions in tropical forest protected areas requires linking interdisciplinary datasets collected across a range of spatial and temporal scales. Recent assessments have shown that forest degradation and loss outside of protected areas is strongly associated with declines in biodiversity within protected areas. Biodiversity monitoring efforts must therefore develop approaches that consider change in the broader landscape, using biophysical and socioeconomic datasets that not only cover the extent of a protected area, but also the region surrounding it. The Tropical Ecology Assessment and Monitoring (TEAM) Network has developed an approach for linking remotely sensed imagery from Landsat and MODIS sensors with in-situ ecological data and socioeconomic datasets to better understand the effects of landscape change on biodiversity. The TEAM Network is a global system for monitoring biodiversity, land use/cover change (LUCC), and climate in sixteen tropical forest sites evenly distributed across global biophysical gradients (rainfall and seasonality) and gradients of expected climate change and land use change. TEAM adopts the Zone of Interaction (ZOI) concept to delineate the spatial extent around protected areas for linking broader-scale trends in LUCC to plot-based monitoring data. This talk reports on a cross-site comparison examining LUCC and biodiversity change across the TEAM network. The analysis indicates a gradient of forest loss in the tropics dependent on landscape-level human factors, such as population and road density. The highest losses of forest cover are associated with changing patterns of land use and agricultural development, particularly plantation forestry in Southeast Asia. While the spatial and temporal resolution of remote sensing-derived datasets continues to increase, a key challenge for monitoring efforts is linking this data to spatially explicit socioeconomic datasets for use in statistical modeling. We will

  9. Post-fragmentation population structure in a cooperative breeding Afrotropical cloud forest bird: emergence of a source-sink population network.

    PubMed

    Husemann, M; Cousseau, L; Callens, T; Matthysen, E; Vangestel, C; Hallmann, C; Lens, L

    2015-03-01

    The impact of demographic parameters on the genetic population structure and viability of organisms is a long-standing issue in the study of fragmented populations. Demographic and genetic tools are now readily available to estimate census and effective population sizes and migration and gene flow rates with increasing precision. Here we analysed the demography and genetic population structure over a recent 15-year time span in five remnant populations of Cabanis's greenbul (Phyllastrephus cabanisi), a cooperative breeding bird in a severely fragmented cloud forest habitat. Contrary to our expectation, genetic admixture and effective population sizes slightly increased, rather than decreased between our two sampling periods. In spite of small effective population sizes in tiny forest remnants, none of the populations showed evidence of a recent population bottleneck. Approximate Bayesian modelling, however, suggested that differentiation of the populations coincided at least partially with an episode of habitat fragmentation. The ratio of meta-Ne to meta-Nc was relatively low for birds, which is expected for cooperative breeding species, while Ne /Nc ratios strongly varied among local populations. While the overall trend of increasing population sizes and genetic admixture may suggest that Cabanis's greenbuls increasingly cope with fragmentation, the time period over which these trends were documented is rather short relative to the average longevity of tropical species. Furthermore, the critically low Nc in the small forest remnants keep the species prone to demographic and environmental stochasticity, and it remains open if, and to what extent, its cooperative breeding behaviour helps to buffer such effects.

  10. Disaggregating Census Data for Population Mapping Using Random Forests with Remotely-Sensed and Ancillary Data

    PubMed Central

    Stevens, Forrest R.; Gaughan, Andrea E.; Linard, Catherine; Tatem, Andrew J.

    2015-01-01

    High resolution, contemporary data on human population distributions are vital for measuring impacts of population growth, monitoring human-environment interactions and for planning and policy development. Many methods are used to disaggregate census data and predict population densities for finer scale, gridded population data sets. We present a new semi-automated dasymetric modeling approach that incorporates detailed census and ancillary data in a flexible, “Random Forest” estimation technique. We outline the combination of widely available, remotely-sensed and geospatial data that contribute to the modeled dasymetric weights and then use the Random Forest model to generate a gridded prediction of population density at ~100 m spatial resolution. This prediction layer is then used as the weighting surface to perform dasymetric redistribution of the census counts at a country level. As a case study we compare the new algorithm and its products for three countries (Vietnam, Cambodia, and Kenya) with other common gridded population data production methodologies. We discuss the advantages of the new method and increases over the accuracy and flexibility of those previous approaches. Finally, we outline how this algorithm will be extended to provide freely-available gridded population data sets for Africa, Asia and Latin America. PMID:25689585

  11. Detecting CO2 Fertilization in Tree Ring Records: Evidence from Natural Populations of Boreal Forest Species

    NASA Astrophysics Data System (ADS)

    Nelson, E. A.; Thomas, S. C.

    2008-12-01

    Global increases of atmospheric CO2 concentration are predicted to enhance tree growth, particularly where water limitation is important, but evidence of CO2 fertilization in Canada's forests is limited. This study examined the effect of increasing atmospheric CO2 concentration on tree ring increments in south-east Yukon, west-central Manitoba and northern Ontario, sampling the dominant tree species at each site: lodgepole pine (Pinus contorta), white spruce (Picea glauca) and black spruce (Picea mariana), respectively. Over 50 tree cores from each site were sampled, analysed for ring-width, cross- dated and averaged, generating a ~100 y chronology for each population. We examined the residuals following a regression with climate variables for a positive trend over time, which has been interpreted in prior studies as evidence for a CO2 fertilization effect. We were only able to detect an increase in ring width residuals over time in the Manitoba white spruce population, which were located at the most water-limited site. We did further analyses to see whether CO2 fertilization was stronger or more detectable in younger trees or more water-limited years. Although we were unable to find any evidence that drier years experienced increases in relative growth as a result of increased CO2 availability, we did find stronger CO2 responses in younger trees. In conclusion, forest populations that are water-limited or young in age are more likely to benefit from global increases in atmospheric CO2 concentration, and are better able to contribute to overall boreal forest carbon sequestration.

  12. Bee Hotels’ as Tools for Native Pollinator Conservation: A Premature Verdict?

    PubMed Central

    MacIvor, J. Scott; Packer, Laurence

    2015-01-01

    Society is increasingly concerned with declining wild bee populations. Although most bees nest in the ground, considerable effort has centered on installing ‘bee hotels’—also known as nest boxes or trap nests—which artificially aggregate nest sites of above ground nesting bees. Campaigns to ‘save the bees’ often promote these devices despite the absence of data indicating they have a positive effect. From a survey of almost 600 bee hotels set up over a period of three years in Toronto, Canada, introduced bees nested at 32.9% of sites and represented 24.6% of more than 27,000 total bees and wasps recorded (47.1% of all bees recorded). Native bees were parasitized more than introduced bees and females of introduced bee species provisioned nests with significantly more female larva each year. Native wasps were significantly more abundant than both native and introduced bees and occupied almost 3/4 of all bee hotels each year; further, introduced wasps were the only group to significantly increase in relative abundance year over year. More research is needed to elucidate the potential pitfalls and benefits of using bee hotels in the conservation and population dynamics of wild native bees. PMID:25785609

  13. Small mammal populations of an agroecosystem in the Atlantic Forest domain, southeastern Brazil.

    PubMed

    D'Andrea, P S; Gentile, R; Maroja, L S; Fernandes, F A; Coura, R; Cerqueira, R

    2007-02-01

    This study reports 2 years of the population dynamics and reproduction of a small mammal community using the removal method. The study was conducted in a rural area of the Atlantic Forest, in Sumidouro, Rio de Janeiro State, Brazil. The population sizes, age structure and reproduction were studied for the four most common species in the study area. The overall diversity was 1.67 and ranged between 0.8 to 1.67. The species richness was 13 considering the whole study. The most abundant species were the rodents Nectomys squamipes (n = 133), Akodon cursor (n = 74), Oligoryzomys nigripes (n = 25) and the marsupials Didelphis aurita (n = 58) and Philander frenatus (n = 50). Seven other rodents were captured once: Necromys lasiurus, Akodon montensis, Sooretamys angouya, Oecomys catherine, Oxymycterus judex, Euryzygomatomys spinosus and Trinomys iheringi. There were higher peaks for diversity and species richness during the winter (dry) months, probably due to higher food availability. The marsupials had a seasonal reproduction with highest population sizes at the end of the rainy seasons. Nectomys squamipes reproduced mostly during rainy periods. Akodon cursor reproduced predominantly in the winter with the highest population peaks occurring during this season. The analysis of the population dynamics of the rodent species indicated that no species behaved as an agricultural pest, probably due to the heterogeneous landscape of high rotativity of vegetable cultivation. Rodent populations were more susceptible to the removal procedure than marsupial ones.

  14. Nosema ceranae in European honey bees (Apis mellifera).

    PubMed

    Fries, Ingemar

    2010-01-01

    Nosema ceranae is a microsporidian parasite described from the Asian honey bee, Apis cerana. The parasite is cross-infective with the European honey bee, Apis mellifera. It is not known when or where N. ceranae first infected European bees, but N. ceranae has probably been infecting European bees for at least two decades. N. ceranae appears to be replacing Nosema apis, at least in some populations of European honey bees. This replacement is an enigma because the spores of the new parasite are less durable than those of N. apis. Virulence data at both the individual bee and at the colony level are conflicting possibly because the impact of this parasite differs in different environments. The recent advancements in N. ceranae genetics, with a draft assembly of the N. ceranae genome available, are discussed and the need for increased research on the impacts of this parasite on European honey bees is emphasized. PMID:19909977

  15. Nosema ceranae in European honey bees (Apis mellifera).

    PubMed

    Fries, Ingemar

    2010-01-01

    Nosema ceranae is a microsporidian parasite described from the Asian honey bee, Apis cerana. The parasite is cross-infective with the European honey bee, Apis mellifera. It is not known when or where N. ceranae first infected European bees, but N. ceranae has probably been infecting European bees for at least two decades. N. ceranae appears to be replacing Nosema apis, at least in some populations of European honey bees. This replacement is an enigma because the spores of the new parasite are less durable than those of N. apis. Virulence data at both the individual bee and at the colony level are conflicting possibly because the impact of this parasite differs in different environments. The recent advancements in N. ceranae genetics, with a draft assembly of the N. ceranae genome available, are discussed and the need for increased research on the impacts of this parasite on European honey bees is emphasized.

  16. Bee-Wild about Pollinators!

    ERIC Educational Resources Information Center

    Johnson, Bonnie; Kil, Jenny; Evans, Elaine; Koomen, Michele Hollingsworth

    2014-01-01

    With their sunny stripes and fuzzy bodies, bees are beloved--but unfortunately, they are in trouble. Bee decline, of both wild bees as well as managed bees like honey bees, has been in the news for the last several years. Habitat loss, diseases, pests, and pesticides have made it difficult for bees to survive in many parts of our world (Walsh…

  17. Human population and socioeconomic modulators of conservation performance in 788 Amazonian and Atlantic Forest reserves.

    PubMed

    de Marques, Ana Alice B; Schneider, Mauricio; Peres, Carlos A

    2016-01-01

    Protected areas form a quintessential component of the global strategy to perpetuate tropical biodiversity within relatively undisturbed wildlands, but they are becoming increasingly isolated by rapid agricultural encroachment. Here we consider a network of 788 forest protected areas (PAs) in the world's largest tropical country to examine the degree to which they remain intact, and their responses to multiple biophysical and socioeconomic variables potentially affecting natural habitat loss under varying contexts of rural development. PAs within the complex Brazilian National System of Conservation Units (SNUC) are broken down into two main classes-strictly protected and sustainable use. Collectively, these account for 22.6% of the forest biomes within Brazil's national territory, primarily within the Amazon and the Atlantic Forest, but are widely variable in size, ecoregional representation, management strategy, and the degree to which they are threatened by human activities both within and outside reserve boundaries. In particular, we examine the variation in habitat conversion rates in both strictly protected and sustainable use reserves as a function of the internal and external human population density, and levels of land-use revenue in adjacent human-dominated landscapes. Our results show that PAs surrounded by heavily settled agro-pastoral landscapes face much greater challenges in retaining their natural vegetation, and that strictly protected areas are considerably less degraded than sustainable use reserves, which can rival levels of habitat degradation within adjacent 10-km buffer areas outside. PMID:27478703

  18. Human population and socioeconomic modulators of conservation performance in 788 Amazonian and Atlantic Forest reserves

    PubMed Central

    Schneider, Mauricio; Peres, Carlos A.

    2016-01-01

    Protected areas form a quintessential component of the global strategy to perpetuate tropical biodiversity within relatively undisturbed wildlands, but they are becoming increasingly isolated by rapid agricultural encroachment. Here we consider a network of 788 forest protected areas (PAs) in the world’s largest tropical country to examine the degree to which they remain intact, and their responses to multiple biophysical and socioeconomic variables potentially affecting natural habitat loss under varying contexts of rural development. PAs within the complex Brazilian National System of Conservation Units (SNUC) are broken down into two main classes—strictly protected and sustainable use. Collectively, these account for 22.6% of the forest biomes within Brazil’s national territory, primarily within the Amazon and the Atlantic Forest, but are widely variable in size, ecoregional representation, management strategy, and the degree to which they are threatened by human activities both within and outside reserve boundaries. In particular, we examine the variation in habitat conversion rates in both strictly protected and sustainable use reserves as a function of the internal and external human population density, and levels of land-use revenue in adjacent human-dominated landscapes. Our results show that PAs surrounded by heavily settled agro-pastoral landscapes face much greater challenges in retaining their natural vegetation, and that strictly protected areas are considerably less degraded than sustainable use reserves, which can rival levels of habitat degradation within adjacent 10-km buffer areas outside. PMID:27478703

  19. Population dynamics of neotropical migratory birds using agriculture-forest mosaics in Campeche, Mexico

    USGS Publications Warehouse

    Wilson, M.H.; Berlanga, M.; Dawson, D.; Wood, P.; Sauer, J.; Robbins, C.S.

    1995-01-01

    In many areas of the tropics, forests are being converted to agriculture and other uses at a rapid rate. Previous research has documented that forest-breeding migratory birds are distributed across a wide variety of habitat types during midwinter. However, to evaluate the relative importance of different habitat types to wintering birds, we need to examine habitat-specific estimates of survival. During the winter of 1992-1993, mist nets, observations of individually marked birds and point counts were used to sample bird populations in a pasture-forest mosaic in southern Mexico. Sampling was conducted four times throughout the winter on a total of six grids. Twenty nets were run for two days in each grid. A total of 129 species were captured and 3,585 individuals banded. Neotropical migrants made up 31% of the species captured and 47% of the individuals banded. The banding data were used to estimate species richness for permanent and winter residents in different habitats and at different time periods. Capture-recapture models were used to estimate overwintering survival for selected species.

  20. Human population and socioeconomic modulators of conservation performance in 788 Amazonian and Atlantic Forest reserves.

    PubMed

    de Marques, Ana Alice B; Schneider, Mauricio; Peres, Carlos A

    2016-01-01

    Protected areas form a quintessential component of the global strategy to perpetuate tropical biodiversity within relatively undisturbed wildlands, but they are becoming increasingly isolated by rapid agricultural encroachment. Here we consider a network of 788 forest protected areas (PAs) in the world's largest tropical country to examine the degree to which they remain intact, and their responses to multiple biophysical and socioeconomic variables potentially affecting natural habitat loss under varying contexts of rural development. PAs within the complex Brazilian National System of Conservation Units (SNUC) are broken down into two main classes-strictly protected and sustainable use. Collectively, these account for 22.6% of the forest biomes within Brazil's national territory, primarily within the Amazon and the Atlantic Forest, but are widely variable in size, ecoregional representation, management strategy, and the degree to which they are threatened by human activities both within and outside reserve boundaries. In particular, we examine the variation in habitat conversion rates in both strictly protected and sustainable use reserves as a function of the internal and external human population density, and levels of land-use revenue in adjacent human-dominated landscapes. Our results show that PAs surrounded by heavily settled agro-pastoral landscapes face much greater challenges in retaining their natural vegetation, and that strictly protected areas are considerably less degraded than sustainable use reserves, which can rival levels of habitat degradation within adjacent 10-km buffer areas outside.

  1. History of population fluctuations and infestations of important forest insects in the Queen Charlotte Islands forest district, 1993. FIDS report No. 94-10. Annual publication

    SciTech Connect

    1994-12-31

    This report provides some history of some important forest insects in the District. It serves to designate the species of insects which cause damage; record the pattern of population fluctuations; designate areas that appear to have chronic problems; and point out the possibility of damage in different areas by insects, including species not known to have caused damage in the Queen Charlotte Islands.

  2. Forest fragments as barriers to fruit fly dispersal: Anastrepha (Diptera: Tephritidae) populations in orchards and adjacent forest fragments in Puerto Rico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    McPhail-type traps baited with ammonium acetate and putrescine were used to monitor populations of Anastrepha obliqua and A. suspensa at four sites in Guánica, Puerto Rico; one forest fragment in Ponce, Puerto Rico; in a commercial mango orchard in Guayanilla, PR; and an experimental carambola orcha...

  3. Detection of Deformed wing virus, a honey bee viral pathogen, in bumble bees (Bombus terrestris and Bombus pascuorum) with wing deformities.

    PubMed

    Genersch, Elke; Yue, Constanze; Fries, Ingemar; de Miranda, Joachim R

    2006-01-01

    Honey bees (Apis mellifera) productively infected with Deformed wing virus (DWV) through Varroa destructor (V. destructor) during pupal stages develop into adults showing wing and other morphological deformities. Here, we report for the first time the occurrence of bumble bees (Bombus terrestris, Bombus pascuorum) exhibiting wing deformities resembling those seen in clinically DWV-infected honey bees. Using specific RT-PCR protocols for the detection of DWV followed by sequencing of the PCR products we could demonstrate that the bumble bees were indeed infected with DWV. Since such deformed bumble bees are not viable DWV infection may pose a serious threat to bumble bee populations.

  4. Management increases genetic diversity of honey bees via admixture.

    PubMed

    Harpur, Brock A; Minaei, Shermineh; Kent, Clement F; Zayed, Amro

    2012-09-01

    The process of domestication often brings about profound changes in levels of genetic variation in animals and plants. The honey bee, Apis mellifera, has been managed by humans for centuries for both honey and wax production and crop pollination. Human management and selective breeding are believed to have caused reductions in genetic diversity in honey bee populations, thereby contributing to the global declines threatening this ecologically and economically important insect. However, previous studies supporting this claim mostly relied on population genetic comparisons of European and African (or Africanized) honey bee races; such conclusions require reassessment given recent evidence demonstrating that the honey bee originated in Africa and colonized Europe via two independent expansions. We sampled honey bee workers from two managed populations in North America and Europe as well as several old-world progenitor populations in Africa, East and West Europe. Managed bees had highly introgressed genomes representing admixture between East and West European progenitor populations. We found that managed honey bees actually have higher levels of genetic diversity compared with their progenitors in East and West Europe, providing an unusual example whereby human management increases genetic diversity by promoting admixture. The relationship between genetic diversity and honey bee declines is tenuous given that managed bees have more genetic diversity than their progenitors and many viable domesticated animals.

  5. Evaluation of the neotropical stingless bee Melipona quadrifasciata (Hymenoptera: Apidae) as pollinator of greenhouse tomatoes.

    PubMed

    Del Sarto, M C L; Peruquetti, R C; Campos, L A O

    2005-04-01

    The Neotropical stingless bee Melipona quadrifasciata Lepeletier was evaluated for pollinating tomatoes (variety Rodas; long-life hybrid) in greenhouses under plastic and with a hydroponic system and "organic concepts" in Minas Gerais State, Brazil. Flowers not pollinated did not set any fruit. Pollination by bees plus manual pollination did not differ from either bee or manual pollination. Maximum fruit diameter, fruit height, and roundness (quotient between maximum fruit diameter and fruit height) were not significantly different between treatments, but fruit visited by M. quadrifasciata had 10.8% less seeds (dry mass) than manual pollination. This apparently low efficiency of M. quadrifasciata pollination was attributed to the overlap of only 30 min between highest bee foraging activity and highest flower stigma receptivity. Thus, it was concluded that M. quadrifasciata is a feasible pollinator of greenhouse tomatoes because of 1) the observed increase in fruit quality with lower mechanical injury than traditional manual pollination, 2) no significant decrease in fruit size, and 3) high price of such product in the market. Some considerations for sustainable use of M. quadrifasciata as greenhouse pollinator are presented. Although techniques for keeping captive colonies of M. quadrifasciata are currently available, the sole current method for acquiring new colonies is removing them from the forest, and if demand was created for large numbers of colonies for commercial use, techniques for captive rearing must be developed to prevent serious declines in wild populations.

  6. Population-genomic variation within RNA viruses of the Western honey bee, Apis mellifera, inferred from deep sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Deep sequencing of viruses isolated from infected hosts is an efficient way to measure population-genetic variation and can reveal patterns of dispersal and natural selection. In this study, we mined existing Illumina sequence reads to investigate single-nucleotide polymorphisms (SNPs) within two RN...

  7. Assessment of indirect pesticide effects on worm-eating warbler populations in a managed forest ecosystem.

    PubMed

    Awkerman, Jill A; Marshall, Matthew R; Williams, Alan B; Gale, George A; Cooper, Robert J; Raimondo, Sandy

    2011-08-01

    Ecological risk assessments rarely evaluate indirect pesticide effects. Pesticides causing no direct mortality in wildlife can still reduce prey availability, resulting in a lower reproductive rate or poor juvenile condition. Few studies have examined these consequences at the population level. We use a four-year data set from a forest ecosystem in which Bacillus thuringiensis kurstaki (Btk) was applied to control gypsy moths (Lymantria dispar L.). Lower worm-eating warbler (Helmitheros vermivorus) productivity on Btk plots contributed to an intrinsic growth rate <1. Altered provisioning behavior by adults led to lower nestling mass in Btk-treated plots, and simulations of reduced juvenile survival expected as a result further reduced population growth rate. The present study explored different spatial representations of treated areas, using a two-patch matrix model incorporating dispersal. Minimal migration from areas with increasing subpopulations could compensate for detrimental reductions in reproductive success and juvenile survival within treated subpopulations. We also simulated population dynamics with different proportions of treated areas to inform management strategies in similar systems. Nontoxic insecticides are capable of impacting nontarget populations with consistent, long-term use and should be evaluated based on the spatial connectivity representative of habitat availability and the time period appropriate for risk assessment of pesticide effects in wildlife populations.

  8. Assessment of indirect pesticide effects on worm-eating warbler populations in a managed forest ecosystem.

    PubMed

    Awkerman, Jill A; Marshall, Matthew R; Williams, Alan B; Gale, George A; Cooper, Robert J; Raimondo, Sandy

    2011-08-01

    Ecological risk assessments rarely evaluate indirect pesticide effects. Pesticides causing no direct mortality in wildlife can still reduce prey availability, resulting in a lower reproductive rate or poor juvenile condition. Few studies have examined these consequences at the population level. We use a four-year data set from a forest ecosystem in which Bacillus thuringiensis kurstaki (Btk) was applied to control gypsy moths (Lymantria dispar L.). Lower worm-eating warbler (Helmitheros vermivorus) productivity on Btk plots contributed to an intrinsic growth rate <1. Altered provisioning behavior by adults led to lower nestling mass in Btk-treated plots, and simulations of reduced juvenile survival expected as a result further reduced population growth rate. The present study explored different spatial representations of treated areas, using a two-patch matrix model incorporating dispersal. Minimal migration from areas with increasing subpopulations could compensate for detrimental reductions in reproductive success and juvenile survival within treated subpopulations. We also simulated population dynamics with different proportions of treated areas to inform management strategies in similar systems. Nontoxic insecticides are capable of impacting nontarget populations with consistent, long-term use and should be evaluated based on the spatial connectivity representative of habitat availability and the time period appropriate for risk assessment of pesticide effects in wildlife populations. PMID:21538489

  9. Discrimination of fish populations using parasites: Random Forests on a 'predictable' host-parasite system.

    PubMed

    Pérez-Del-Olmo, A; Montero, F E; Fernández, M; Barrett, J; Raga, J A; Kostadinova, A

    2010-10-01

    We address the effect of spatial scale and temporal variation on model generality when forming predictive models for fish assignment using a new data mining approach, Random Forests (RF), to variable biological markers (parasite community data). Models were implemented for a fish host-parasite system sampled along the Mediterranean and Atlantic coasts of Spain and were validated using independent datasets. We considered 2 basic classification problems in evaluating the importance of variations in parasite infracommunities for assignment of individual fish to their populations of origin: multiclass (2-5 population models, using 2 seasonal replicates from each of the populations) and 2-class task (using 4 seasonal replicates from 1 Atlantic and 1 Mediterranean population each). The main results are that (i) RF are well suited for multiclass population assignment using parasite communities in non-migratory fish; (ii) RF provide an efficient means for model cross-validation on the baseline data and this allows sample size limitations in parasite tag studies to be tackled effectively; (iii) the performance of RF is dependent on the complexity and spatial extent/configuration of the problem; and (iv) the development of predictive models is strongly influenced by seasonal change and this stresses the importance of both temporal replication and model validation in parasite tagging studies.

  10. Mast pulses shape trophic interactions between fluctuating rodent populations in a primeval forest.

    PubMed

    Selva, Nuria; Hobson, Keith A; Cortés-Avizanda, Ainara; Zalewski, Andrzej; Donázar, José Antonio

    2012-01-01

    How different functional responses of consumers exploiting pulsed resources affect community dynamics is an ongoing question in ecology. Tree masting is a common resource pulse in terrestrial ecosystems that can drive rodent population cycles. Using stable isotope (δ(13)C, δ(15)N) analyses, we investigated the dietary response of two fluctuating rodent species, the yellow-necked mouse Apodemus flavicollis and the bank vole Myodes glareolus, to mast events in Białowieża Forest (NE Poland). Rodent hair samples were obtained non-invasively from faeces of their predators for an 11-year period that encompassed two mast events. Spectacular seed crops of deciduous trees, namely oak Quercus robur and hornbeam Carpinus betulus, occur after several intermediate years of moderate seed production, with a post-mast year characterised by a nil crop. While a Bayesian isotopic (SIAR) mixing model showed a variety of potential vegetation inputs to rodent diets, the isotopic niche of the yellow-necked mouse was strongly associated with mast of deciduous trees (>80% of diet), showing no variation among years of different seed crop. However, bank voles showed a strong functional response; in mast years the vole shifted its diet from herbs in deciduous forest (~66% of diet) to mast (~74%). Only in mast years did the isotopic niche of both rodent species overlap. Previous research showed that bank voles, subordinate and more generalist than mice, showed higher fluctuations in numbers in response to masting. This study provides unique data on the functional response of key pulse consumers in forest food webs, and contributes to our understanding of rodent population fluctuations and the mechanisms governing pulse-consumer interactions. PMID:23251475

  11. Mast pulses shape trophic interactions between fluctuating rodent populations in a primeval forest.

    PubMed

    Selva, Nuria; Hobson, Keith A; Cortés-Avizanda, Ainara; Zalewski, Andrzej; Donázar, José Antonio

    2012-01-01

    How different functional responses of consumers exploiting pulsed resources affect community dynamics is an ongoing question in ecology. Tree masting is a common resource pulse in terrestrial ecosystems that can drive rodent population cycles. Using stable isotope (δ(13)C, δ(15)N) analyses, we investigated the dietary response of two fluctuating rodent species, the yellow-necked mouse Apodemus flavicollis and the bank vole Myodes glareolus, to mast events in Białowieża Forest (NE Poland). Rodent hair samples were obtained non-invasively from faeces of their predators for an 11-year period that encompassed two mast events. Spectacular seed crops of deciduous trees, namely oak Quercus robur and hornbeam Carpinus betulus, occur after several intermediate years of moderate seed production, with a post-mast year characterised by a nil crop. While a Bayesian isotopic (SIAR) mixing model showed a variety of potential vegetation inputs to rodent diets, the isotopic niche of the yellow-necked mouse was strongly associated with mast of deciduous trees (>80% of diet), showing no variation among years of different seed crop. However, bank voles showed a strong functional response; in mast years the vole shifted its diet from herbs in deciduous forest (~66% of diet) to mast (~74%). Only in mast years did the isotopic niche of both rodent species overlap. Previous research showed that bank voles, subordinate and more generalist than mice, showed higher fluctuations in numbers in response to masting. This study provides unique data on the functional response of key pulse consumers in forest food webs, and contributes to our understanding of rodent population fluctuations and the mechanisms governing pulse-consumer interactions.

  12. Mast Pulses Shape Trophic Interactions between Fluctuating Rodent Populations in a Primeval Forest

    PubMed Central

    Selva, Nuria; Hobson, Keith A.; Cortés-Avizanda, Ainara; Zalewski, Andrzej; Donázar, José Antonio

    2012-01-01

    How different functional responses of consumers exploiting pulsed resources affect community dynamics is an ongoing question in ecology. Tree masting is a common resource pulse in terrestrial ecosystems that can drive rodent population cycles. Using stable isotope (δ13C, δ15N) analyses, we investigated the dietary response of two fluctuating rodent species, the yellow-necked mouse Apodemus flavicollis and the bank vole Myodes glareolus, to mast events in Białowieża Forest (NE Poland). Rodent hair samples were obtained non-invasively from faeces of their predators for an 11-year period that encompassed two mast events. Spectacular seed crops of deciduous trees, namely oak Quercus robur and hornbeam Carpinus betulus, occur after several intermediate years of moderate seed production, with a post-mast year characterised by a nil crop. While a Bayesian isotopic (SIAR) mixing model showed a variety of potential vegetation inputs to rodent diets, the isotopic niche of the yellow-necked mouse was strongly associated with mast of deciduous trees (>80% of diet), showing no variation among years of different seed crop. However, bank voles showed a strong functional response; in mast years the vole shifted its diet from herbs in deciduous forest (∼66% of diet) to mast (∼74%). Only in mast years did the isotopic niche of both rodent species overlap. Previous research showed that bank voles, subordinate and more generalist than mice, showed higher fluctuations in numbers in response to masting. This study provides unique data on the functional response of key pulse consumers in forest food webs, and contributes to our understanding of rodent population fluctuations and the mechanisms governing pulse–consumer interactions. PMID:23251475

  13. Depression of belowground respiration rates at simulated high moose population densities in boreal forests.

    PubMed

    Persson, Inga-Lill; Nilsson, Mats B; Pastor, John; Eriksson, Tobias; Bergström, Roger; Danell, Kjell

    2009-10-01

    Large herbivores can affect the carbon cycle in boreal forests by changing productivity and plant species composition, which in turn could ultimately alter litter production, nutrient cycling, and the partitioning between aboveground and belowground allocation of carbon. Here we experimentally tested how moose (Alces alces) at different simulated population densities affected belowground respiration rates (estimated as CO2 flux) in young boreal forest stands situated along a site productivity gradient. At high simulated population density, moose browsing considerably depressed belowground respiration rates (24-56% below that of no-moose controls) except during June, where the difference only was 10%. Moose browsing depressed belowground respiration the most on low-productivity sites. Soil moisture and temperature did not affect respiration rates. Impact of moose on belowground respiration was closely linked to litter production and followed Michaelis-Menten dynamics. The main mechanism by which moose decrease belowground respiration rates is likely their effect on photosynthetic biomass (especially decreased productivity of deciduous trees) and total litter production. An increased productivity of deciduous trees along the site productivity gradient causes an unequal effect of moose along the same gradient. The rapid growth of deciduous trees may offer higher resilience against negative effects of moose browsing on litter production and photosynthate allocation to roots.

  14. Bird populations on the Island of Tinian: persistence despite wholesale loss of native forests

    USGS Publications Warehouse

    Camp, Richard J.; Amidon, Frederick A.; Marshall, Ann P.; Pratt, Thane K.

    2012-01-01

    Bird habitat on the island of Tinian, Mariana Islands, has been substantially altered, and only around 5% of the island has native forest today. The modern bird fauna is likely to be a subset of the original avifauna where only species tolerant to native forest loss and human disturbance have survived. Avian surveys were conducted on the island in 2008 by the U.S. Fish and Wildlife Service to provide current densities and abundances of the remaining species, and assess population trends using data collected from previous surveys. During the three surveys (1982, 1996, and 2008), 18 species were detected, and abundances and trends were assessed for 11 species. Five of the nine native species and one alien bird have increased since 1982. Three native birds—Mariana Fruit-Dove (Ptilinopusroseicapilla), Micronesian Honeyeater (Myzomela rubratra), and Tinian Monarch (Monarcha takatsukasae)—have decreased since 1982. Trends for the remaining two birds (one native and one alien) were considered relatively stable. Only five birds, including the Tinian Monarch, showed significant differences among regions of Tinian by year. Increased development on Tinian may result in increases in habitat clearing and expansion of human-dominated habitats, and declines in some bird populations would likely continue or be exacerbated with these actions. Expanded development activities on Tinian would also mean increased cargo movement between Guam and Tinian, elevating the probability of transporting the Brown Tree Snake (Boiga irregularis) to Tinian, which would lead to precipitous decreases and extinctions.

  15. Urban gardens promote bee foraging over natural habitats and plantations.

    PubMed

    Kaluza, Benjamin F; Wallace, Helen; Heard, Tim A; Klein, Alexandra-Maria; Leonhardt, Sara D

    2016-03-01

    Increasing human land use for agriculture and housing leads to the loss of natural habitat and to widespread declines in wild bees. Bee foraging dynamics and fitness depend on the availability of resources in the surrounding landscape, but how precisely landscape related resource differences affect bee foraging patterns remains unclear. To investigate how landscape and its interaction with season and weather drive foraging and resource intake in social bees, we experimentally compared foraging activity, the allocation of foragers to different resources (pollen, nectar, and resin) and overall resource intake in the Australian stingless bee Tetragonula carbonaria (Apidae, Meliponini). Bee colonies were monitored in different seasons over two years. We compared foraging patterns and resource intake between the bees' natural habitat (forests) and two landscapes differently altered by humans (suburban gardens and agricultural macadamia plantations). We found foraging activity as well as pollen and nectar forager numbers to be highest in suburban gardens, intermediate in forests and low in plantations. Foraging patterns further differed between seasons, but seasonal variations strongly differed between landscapes. Sugar and pollen intake was low in plantations, but contrary with our predictions, it was even higher in gardens than in forests. In contrast, resin intake was similar across landscapes. Consequently, differences in resource availability between natural and altered landscapes strongly affect foraging patterns and thus resource intake in social bees. While agricultural monocultures largely reduce foraging success, suburban gardens can increase resource intake well above rates found in natural habitats of bees, indicating that human activities can both decrease and increase the availability of resources in a landscape and thus reduce or enhance bee fitness.

  16. Urban gardens promote bee foraging over natural habitats and plantations.

    PubMed

    Kaluza, Benjamin F; Wallace, Helen; Heard, Tim A; Klein, Alexandra-Maria; Leonhardt, Sara D

    2016-03-01

    Increasing human land use for agriculture and housing leads to the loss of natural habitat and to widespread declines in wild bees. Bee foraging dynamics and fitness depend on the availability of resources in the surrounding landscape, but how precisely landscape related resource differences affect bee foraging patterns remains unclear. To investigate how landscape and its interaction with season and weather drive foraging and resource intake in social bees, we experimentally compared foraging activity, the allocation of foragers to different resources (pollen, nectar, and resin) and overall resource intake in the Australian stingless bee Tetragonula carbonaria (Apidae, Meliponini). Bee colonies were monitored in different seasons over two years. We compared foraging patterns and resource intake between the bees' natural habitat (forests) and two landscapes differently altered by humans (suburban gardens and agricultural macadamia plantations). We found foraging activity as well as pollen and nectar forager numbers to be highest in suburban gardens, intermediate in forests and low in plantations. Foraging patterns further differed between seasons, but seasonal variations strongly differed between landscapes. Sugar and pollen intake was low in plantations, but contrary with our predictions, it was even higher in gardens than in forests. In contrast, resin intake was similar across landscapes. Consequently, differences in resource availability between natural and altered landscapes strongly affect foraging patterns and thus resource intake in social bees. While agricultural monocultures largely reduce foraging success, suburban gardens can increase resource intake well above rates found in natural habitats of bees, indicating that human activities can both decrease and increase the availability of resources in a landscape and thus reduce or enhance bee fitness. PMID:26848387

  17. Pesticide use within a pollinator-dependent crop has negative effects on the abundance and species richness of sweat bees, Lasioglossum spp., and on bumble bee colony growth.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pesticides are implicated in current bee declines. Wild bees that nest or forage within agroecosystems may be exposed to numerous pesticides applied throughout their life cycles, with potential additive or synergistic effects. In pollinator-dependent crops, pesticides may reduce bee populations, cre...

  18. Effects of various breeding strategies on diploid drone frequency and quantitative traits in a honey bee population.

    PubMed

    Omholt, S W; Adnøy, T

    1994-11-01

    When selecting in a finite population of honeybees there is a conflict between gain in a quantitative trait and increasing homozygosity, and therefore the frequency of inviable diploid drones. The consequences when using different mating, import, and selection strategies on diploid drone frequency and genetic gain, was explored with Monte Carlo computer simulations.Within a closed population breeding structure, mass selection gave the highest genetic gain in the quantitative trait, but also the largest increase in percentage diploid drones and queens with unacceptably-low brood viability. Mass selection combined with truncation selection against queens having more than 15% diploid drones gave a comparable genetic gain and was the best strategy of the ones studied to avoid diploid drones. Within-family selection (one replacement per sib group) gave the least genetic gain, and a frequency of diploid drones comparable to random (no) selection. It was intermediate between mass selection and mass selection combined with viability selection concerning the frequency of diploid drones.Insemination with pooled and homogenized semen originating from all breeder queens (30), as compared to natural mating with 12 randomly-selected drones, had little effect on the genetic gain and on the overall frequency of diploid drones (10 to 15% by generation 20).The effect of opening the closed breeding population for the import of external queens every generation, by exchanging breeder queens of lowest performance with a corresponding number of new queens (5, 10and 15 out of 30), was also investigated. Under mass selection (natural mating as well as artificial insemination) the frequency of diploid drones and the proportion of queens discarded were reduced because of low brood viability. However, artificial insemination was superior to natural mating considering the latter criterion. If the imported queens were at the same genetic level for the quantitative trait under selection as the

  19. Effects of various breeding strategies on diploid drone frequency and quantitative traits in a honey bee population.

    PubMed

    Omholt, S W; Adnøy, T

    1994-11-01

    When selecting in a finite population of honeybees there is a conflict between gain in a quantitative trait and increasing homozygosity, and therefore the frequency of inviable diploid drones. The consequences when using different mating, import, and selection strategies on diploid drone frequency and genetic gain, was explored with Monte Carlo computer simulations.Within a closed population breeding structure, mass selection gave the highest genetic gain in the quantitative trait, but also the largest increase in percentage diploid drones and queens with unacceptably-low brood viability. Mass selection combined with truncation selection against queens having more than 15% diploid drones gave a comparable genetic gain and was the best strategy of the ones studied to avoid diploid drones. Within-family selection (one replacement per sib group) gave the least genetic gain, and a frequency of diploid drones comparable to random (no) selection. It was intermediate between mass selection and mass selection combined with viability selection concerning the frequency of diploid drones.Insemination with pooled and homogenized semen originating from all breeder queens (30), as compared to natural mating with 12 randomly-selected drones, had little effect on the genetic gain and on the overall frequency of diploid drones (10 to 15% by generation 20).The effect of opening the closed breeding population for the import of external queens every generation, by exchanging breeder queens of lowest performance with a corresponding number of new queens (5, 10and 15 out of 30), was also investigated. Under mass selection (natural mating as well as artificial insemination) the frequency of diploid drones and the proportion of queens discarded were reduced because of low brood viability. However, artificial insemination was superior to natural mating considering the latter criterion. If the imported queens were at the same genetic level for the quantitative trait under selection as the

  20. Field-level sublethal effects of approved bee hive chemicals on Honey Bees (Apis mellifera L).

    PubMed

    Berry, Jennifer A; Hood, W Michael; Pietravalle, Stéphane; Delaplane, Keith S

    2013-01-01

    In a study replicated across two states and two years, we tested the sublethal effects on honey bees of the miticides Apistan (tau fluvalinate) and Check Mite+ (coumaphos) and the wood preservative copper naphthenate applied at label rates in field conditions. A continuous covariate, a colony Varroa mite index, helped us disambiguate the effects of the chemicals on bees while adjusting for a presumed benefit of controlling mites. Mite levels in colonies treated with Apistan or Check Mite+ were not different from levels in non-treated controls. Experimental chemicals significantly decreased 3-day brood survivorship and increased construction of queen supercedure cells compared to non-treated controls. Bees exposed to Check Mite+ as immatures had higher legacy mortality as adults relative to non-treated controls, whereas bees exposed to Apistan had improved legacy mortality relative to non-treated controls. Relative to non-treated controls, Check Mite+ increased adult emergence weight. Although there was a treatment effect on a test of associative learning, it was not possible to statistically separate the treatment means, but bees treated with Apistan performed comparatively well. And finally, there were no detected effects of bee hive chemical on colony bee population, amount of brood, amount of honey, foraging rate, time required for marked released bees to return to their nest, percentage of released bees that return to the nest, and colony Nosema spore loads. To our knowledge, this is the first study to examine sublethal effects of bee hive chemicals applied at label rates under field conditions while disambiguating the results from mite control benefits realized from the chemicals. Given the poor performance of the miticides at reducing mites and their inconsistent effects on the host, these results defend the use of bee health management practices that minimize use of exotic hive chemicals.

  1. Field-Level Sublethal Effects of Approved Bee Hive Chemicals on Honey Bees (Apis mellifera L)

    PubMed Central

    Berry, Jennifer A.; Hood, W. Michael; Pietravalle, Stéphane; Delaplane, Keith S.

    2013-01-01

    In a study replicated across two states and two years, we tested the sublethal effects on honey bees of the miticides Apistan (tau fluvalinate) and Check Mite+ (coumaphos) and the wood preservative copper naphthenate applied at label rates in field conditions. A continuous covariate, a colony Varroa mite index, helped us disambiguate the effects of the chemicals on bees while adjusting for a presumed benefit of controlling mites. Mite levels in colonies treated with Apistan or Check Mite+ were not different from levels in non-treated controls. Experimental chemicals significantly decreased 3-day brood survivorship and increased construction of queen supercedure cells compared to non-treated controls. Bees exposed to Check Mite+ as immatures had higher legacy mortality as adults relative to non-treated controls, whereas bees exposed to Apistan had improved legacy mortality relative to non-treated controls. Relative to non-treated controls, Check Mite+ increased adult emergence weight. Although there was a treatment effect on a test of associative learning, it was not possible to statistically separate the treatment means, but bees treated with Apistan performed comparatively well. And finally, there were no detected effects of bee hive chemical on colony bee population, amount of brood, amount of honey, foraging rate, time required for marked released bees to return to their nest, percentage of released bees that return to the nest, and colony Nosema spore loads. To our knowledge, this is the first study to examine sublethal effects of bee hive chemicals applied at label rates under field conditions while disambiguating the results from mite control benefits realized from the chemicals. Given the poor performance of the miticides at reducing mites and their inconsistent effects on the host, these results defend the use of bee health management practices that minimize use of exotic hive chemicals. PMID:24204638

  2. Avian malaria in Hawaiian forest birds: Infection and population impacts across species and elevations

    USGS Publications Warehouse

    Samuel, Michael D.; Woodworth, Bethany L.; Atkinson, Carter T.; Hart, P. J.; LaPointe, Dennis

    2015-01-01

    Wildlife diseases can present significant threats to ecological systems and biological diversity, as well as domestic animal and human health. However, determining the dynamics of wildlife diseases and understanding the impact on host populations is a significant challenge. In Hawai‘i, there is ample circumstantial evidence that introduced avian malaria (Plasmodium relictum) has played an important role in the decline and extinction of many native forest birds. However, few studies have attempted to estimate disease transmission and mortality, survival, and individual species impacts in this distinctive ecosystem. We combined multi-state capture-recapture (longitudinal) models with cumulative age-prevalence (cross-sectional) models to evaluate these patterns in Apapane, Hawai‘i Amakihi, and Iiwi in low-, mid-, and high-elevation forests on the island of Hawai‘i based on four longitudinal studies of 3–7 years in length. We found species-specific patterns of malaria prevalence, transmission, and mortality rates that varied among elevations, likely in response to ecological factors that drive mosquito abundance. Malaria infection was highest at low elevations, moderate at mid elevations, and limited in high-elevation forests. Infection rates were highest for Iiwi and Apapane, likely contributing to the absence of these species in low-elevation forests. Adult malaria fatality rates were highest for Iiwi, intermediate for Amakihi at mid and high elevations, and lower for Apapane; low-elevation Amakihi had the lowest malaria fatality, providing strong evidence of malaria tolerance in this low-elevation population. Our study indicates that hatch-year birds may have greater malaria infection and/or fatality rates than adults. Our study also found that mosquitoes prefer feeding on Amakihi rather than Apapane, but Apapane are likely a more important reservoir for malaria transmission to mosquitoes. Our approach, based on host abundance and infection rates, may be an

  3. Spatial and Temporal Analysis of Populations of the Sudden Oak Death Pathogen in Oregon Forests.

    PubMed

    Kamvar, Z N; Larsen, M M; Kanaskie, A M; Hansen, E M; Grünwald, N J

    2015-07-01

    Sudden oak death caused by the oomycete Phytophthora ramorum was first discovered in California toward the end of the 20th century and subsequently emerged on tanoak forests in Oregon before its first detection in 2001 by aerial surveys. The Oregon Department of Forestry has since monitored the epidemic and sampled symptomatic tanoak trees from 2001 to the present. Populations sampled over this period were genotyped using microsatellites and studied to infer the population genetic history. To date, only the NA1 clonal lineage is established in this region, although three lineages exist on the North American west coast. The original introduction into the Joe Hall area eventually spread to several regions: mostly north but also east and southwest. A new introduction into Hunter Creek appears to correspond to a second introduction not clustering with the early introduction. Our data are best explained by both introductions originating from nursery populations in California or Oregon and resulting from two distinct introduction events. Continued vigilance and eradication of nursery populations of P. ramorum are important to avoid further emergence and potential introduction of other clonal lineages.

  4. Spatial and Temporal Analysis of Populations of the Sudden Oak Death Pathogen in Oregon Forests.

    PubMed

    Kamvar, Z N; Larsen, M M; Kanaskie, A M; Hansen, E M; Grünwald, N J

    2015-07-01

    Sudden oak death caused by the oomycete Phytophthora ramorum was first discovered in California toward the end of the 20th century and subsequently emerged on tanoak forests in Oregon before its first detection in 2001 by aerial surveys. The Oregon Department of Forestry has since monitored the epidemic and sampled symptomatic tanoak trees from 2001 to the present. Populations sampled over this period were genotyped using microsatellites and studied to infer the population genetic history. To date, only the NA1 clonal lineage is established in this region, although three lineages exist on the North American west coast. The original introduction into the Joe Hall area eventually spread to several regions: mostly north but also east and southwest. A new introduction into Hunter Creek appears to correspond to a second introduction not clustering with the early introduction. Our data are best explained by both introductions originating from nursery populations in California or Oregon and resulting from two distinct introduction events. Continued vigilance and eradication of nursery populations of P. ramorum are important to avoid further emergence and potential introduction of other clonal lineages. PMID:26068281

  5. Gentle Africanized bees on an oceanic island

    PubMed Central

    Rivera-Marchand, Bert; Oskay, Devrim; Giray, Tugrul

    2012-01-01

    Oceanic islands have reduced resources and natural enemies and potentially affect life history traits of arriving organisms. Among the most spectacular invasions in the Western hemisphere is that of the Africanized honeybee. We hypothesized that in the oceanic island Puerto Rico, Africanized bees will exhibit differences from the mainland population such as for defensiveness and other linked traits. We evaluated the extent of Africanization through three typical Africanized traits: wing size, defensive behavior, and resistance to Varroa destructor mites. All sampled colonies were Africanized by maternal descent, with over 65% presence of European alleles at the S-3 nuclear locus. In two assays evaluating defense, Puerto Rican bees showed low defensiveness similar to European bees. In morphology and resistance to mites, Africanized bees from Puerto Rico are similar to other Africanized bees. In behavioral assays on mechanisms of resistance to Varroa, we directly observed that Puerto Rican Africanized bees groomed-off and bit the mites as been observed in other studies. In no other location, Africanized bees have reduced defensiveness while retaining typical traits such as wing size and mite resistance. This mosaic of traits that has resulted during the invasion of an oceanic island has implications for behavior, evolution, and agriculture. PMID:23144660

  6. Gentle Africanized bees on an oceanic island.

    PubMed

    Rivera-Marchand, Bert; Oskay, Devrim; Giray, Tugrul

    2012-11-01

    Oceanic islands have reduced resources and natural enemies and potentially affect life history traits of arriving organisms. Among the most spectacular invasions in the Western hemisphere is that of the Africanized honeybee. We hypothesized that in the oceanic island Puerto Rico, Africanized bees will exhibit differences from the mainland population such as for defensiveness and other linked traits. We evaluated the extent of Africanization through three typical Africanized traits: wing size, defensive behavior, and resistance to Varroa destructor mites. All sampled colonies were Africanized by maternal descent, with over 65% presence of European alleles at the S-3 nuclear locus. In two assays evaluating defense, Puerto Rican bees showed low defensiveness similar to European bees. In morphology and resistance to mites, Africanized bees from Puerto Rico are similar to other Africanized bees. In behavioral assays on mechanisms of resistance to Varroa, we directly observed that Puerto Rican Africanized bees groomed-off and bit the mites as been observed in other studies. In no other location, Africanized bees have reduced defensiveness while retaining typical traits such as wing size and mite resistance. This mosaic of traits that has resulted during the invasion of an oceanic island has implications for behavior, evolution, and agriculture.

  7. A survey of cavity-nesting bees and wasps in loblolly pine stands of the Savannah River Site, Aiken County, South Carolina.

    SciTech Connect

    Horn, S.; Hanula, J., L.

    2004-03-10

    Horn, Scott, and James L. Hanula. 2004. A survey of cavity-nesting bees and wasps in loblolly pine stands of the Savannah River Site, Aiken County, South Carolina. 39(3): 464-469. Abstract: In recent years concern over widespread losses in biodiversity has grown to include a possible decline of many native pollinators, primarily bees. Factors such as habitat fragmentation, agricultural practices, use of pesticides, the introduction of invasive species, or changes in land use may negatively impact these vital organisims. Most reported studies show that human impacts on pollinators are overwhelmingly negative. Reductions in pollinator populations may profoundly impact plant population dynamics and ecosystem function. Little baseline data exists on the diversity and relative abundance of bees and wasps in southern forests. The objective of this study was to develop a simple, effective method of surveying cavity-nesting bees and wasps and to determine species diversity in mature forests of loblolly pine, the most widely planted tree species in the southern United States.

  8. Local bumble bee decline linked to recovery of honey bees, drought effects on floral resources.

    PubMed

    Thomson, Diane M

    2016-10-01

    Time series of abundances are critical for understanding how abiotic factors and species interactions affect population dynamics, but are rarely linked with experiments and also scarce for bee pollinators. This gap is important given concerns about declines in some bee species. I monitored honey bee (Apis mellifera) and bumble bee (Bombus spp.) foragers in coastal California from 1999, when feral A. mellifera populations were low due to Varroa destructor, until 2014. Apis mellifera increased substantially, except between 2006 and 2011, coinciding with declines in managed populations. Increases in A. mellifera strongly correlated with declines in Bombus and reduced diet overlap between them, suggesting resource competition consistent with past experimental results. Lower Bombus numbers also correlated with diminished floral resources. Declines in floral abundances were associated with drought and reduced spring rainfall. These results illustrate how competition with an introduced species may interact with climate to drive local decline of native pollinators. PMID:27539950

  9. Local bumble bee decline linked to recovery of honey bees, drought effects on floral resources.

    PubMed

    Thomson, Diane M

    2016-10-01

    Time series of abundances are critical for understanding how abiotic factors and species interactions affect population dynamics, but are rarely linked with experiments and also scarce for bee pollinators. This gap is important given concerns about declines in some bee species. I monitored honey bee (Apis mellifera) and bumble bee (Bombus spp.) foragers in coastal California from 1999, when feral A. mellifera populations were low due to Varroa destructor, until 2014. Apis mellifera increased substantially, except between 2006 and 2011, coinciding with declines in managed populations. Increases in A. mellifera strongly correlated with declines in Bombus and reduced diet overlap between them, suggesting resource competition consistent with past experimental results. Lower Bombus numbers also correlated with diminished floral resources. Declines in floral abundances were associated with drought and reduced spring rainfall. These results illustrate how competition with an introduced species may interact with climate to drive local decline of native pollinators.

  10. Classical conditioning of proboscis extension in harnessed Africanized honey bee queens (Apis mellifera L.).

    PubMed

    Aquino, Italo S; Abramson, Charles I; Soares, Ademilson E E; Fernandes, Andrea Cardoso; Benbassat, Danny

    2004-06-01

    Experiments are reported on learning in virgin Africanized honey bee queens (Apis mellifera L.). Queens restrained in a "Pavlovian harness" received a pairing of hexanal odor with a 1.8-M feeding of sucrose solution. Compared to explicitly unpaired controls, acquisition was rapid in reaching about 90%. Acquisition was also rapid in queens receiving an unconditioned stimulus of "bee candy" or an unconditioned stimulus administered by worker bees. During extinction the conditioned response declines. The steepest decline was observed in queens receiving an unconditioned stimulus of bee candy. These findings extend previous work on learning of Afrianized honey bee workers to a population of queen bees.

  11. Classical conditioning of proboscis extension in harnessed Africanized honey bee queens (Apis mellifera L.).

    PubMed

    Aquino, Italo S; Abramson, Charles I; Soares, Ademilson E E; Fernandes, Andrea Cardoso; Benbassat, Danny

    2004-06-01

    Experiments are reported on learning in virgin Africanized honey bee queens (Apis mellifera L.). Queens restrained in a "Pavlovian harness" received a pairing of hexanal odor with a 1.8-M feeding of sucrose solution. Compared to explicitly unpaired controls, acquisition was rapid in reaching about 90%. Acquisition was also rapid in queens receiving an unconditioned stimulus of "bee candy" or an unconditioned stimulus administered by worker bees. During extinction the conditioned response declines. The steepest decline was observed in queens receiving an unconditioned stimulus of bee candy. These findings extend previous work on learning of Afrianized honey bee workers to a population of queen bees. PMID:15362396

  12. Population dynamics in changing environments: the case of an eruptive forest pest species.

    PubMed

    Kausrud, Kyrre; Okland, Bjørn; Skarpaas, Olav; Grégoire, Jean-Claude; Erbilgin, Nadir; Stenseth, Nils Chr

    2012-02-01

    In recent decades we have seen rapid and co-occurring changes in landscape structure, species distributions and even climate as consequences of human activity. Such changes affect the dynamics of the interaction between major forest pest species, such as bark beetles (Coleoptera: Curculionidae, Scolytinae), and their host trees. Normally breeding mostly in broken or severely stressed spruce; at high population densities some bark beetle species can colonise and kill healthy trees on scales ranging from single trees in a stand to multi-annual landscape-wide outbreaks. In Eurasia, the largest outbreaks are caused by the spruce bark beetle, Ips typographus (Linnaeus), which is common and shares a wide distribution with its main host, Norway spruce (Picea abies Karst.). A large literature is now available, from which this review aims to synthesize research relevant for the population dynamics of I. typographus and co-occurring species under changing conditions. We find that spruce bark beetle population dynamics tend to be metastable, but that mixed-species and age-heterogeneous forests with good site-matching tend to be less susceptible to large-scale outbreaks. While large accumulations of logs should be removed and/or debarked before the next swarming period, intensive removal of all coarse dead wood may be counterproductive, as it reduces the diversity of predators that in some areas may play a role in keeping I. typographus populations below the outbreak threshold, and sanitary logging frequently causes edge effects and root damage, reducing the resistance of remaining trees. It is very hard to predict the outcome of interspecific interactions due to invading beetle species or I. typographus establishing outside its current range, as they can be of varying sign and strength and may fluctuate depending on environmental factors and population phase. Most research indicates that beetle outbreaks will increase in frequency and magnitude as temperature, wind speed and

  13. Queens become workers: pesticides alter caste differentiation in bees.

    PubMed

    Dos Santos, Charles F; Acosta, André L; Dorneles, Andressa L; Dos Santos, Patrick D S; Blochtein, Betina

    2016-08-17

    Bees are important for the world biodiversity and economy because they provide key pollination services in forests and crops. However, pesticide use in crops has adversely affected (decreased) queen production because of increased mortality among larvae. Here, we demonstrated that in vitro-reared queens of a neotropical social bee species (Plebeia droryana) also showed high larval mortality after exposure to an organophosphate pesticide (chlorpyrifos) via larval food. Moreover, most of the surviving larvae that were destined to develop into queens became workers more likely because they ate less food than expected without pesticide skewing thus caste differentiation in this bee species. This adverse effect has not been previously reported for any other social insects, such as honeybees or bumblebees. Queens are essential for breeding and colony growth. Therefore, if our data are applicable to other pantropical social bee species across the globe, it is likely that these bees are at a serious risk of failure to form new colonies.

  14. Queens become workers: pesticides alter caste differentiation in bees

    PubMed Central

    dos Santos, Charles F.; Acosta, André L.; Dorneles, Andressa L.; dos Santos, Patrick D. S.; Blochtein, Betina

    2016-01-01

    Bees are important for the world biodiversity and economy because they provide key pollination services in forests and crops. However, pesticide use in crops has adversely affected (decreased) queen production because of increased mortality among larvae. Here, we demonstrated that in vitro-reared queens of a neotropical social bee species (Plebeia droryana) also showed high larval mortality after exposure to an organophosphate pesticide (chlorpyrifos) via larval food. Moreover, most of the surviving larvae that were destined to develop into queens became workers more likely because they ate less food than expected without pesticide skewing thus caste differentiation in this bee species. This adverse effect has not been previously reported for any other social insects, such as honeybees or bumblebees. Queens are essential for breeding and colony growth. Therefore, if our data are applicable to other pantropical social bee species across the globe, it is likely that these bees are at a serious risk of failure to form new colonies. PMID:27530246

  15. Queens become workers: pesticides alter caste differentiation in bees.

    PubMed

    Dos Santos, Charles F; Acosta, André L; Dorneles, Andressa L; Dos Santos, Patrick D S; Blochtein, Betina

    2016-01-01

    Bees are important for the world biodiversity and economy because they provide key pollination services in forests and crops. However, pesticide use in crops has adversely affected (decreased) queen production because of increased mortality among larvae. Here, we demonstrated that in vitro-reared queens of a neotropical social bee species (Plebeia droryana) also showed high larval mortality after exposure to an organophosphate pesticide (chlorpyrifos) via larval food. Moreover, most of the surviving larvae that were destined to develop into queens became workers more likely because they ate less food than expected without pesticide skewing thus caste differentiation in this bee species. This adverse effect has not been previously reported for any other social insects, such as honeybees or bumblebees. Queens are essential for breeding and colony growth. Therefore, if our data are applicable to other pantropical social bee species across the globe, it is likely that these bees are at a serious risk of failure to form new colonies. PMID:27530246

  16. Population genetics of the wood-rotting basidiomycete Armillaria cepistipes in a fragmented forest landscape.

    PubMed

    Heinzelmann, Renate; Rigling, Daniel; Prospero, Simone

    2012-09-01

    Armillaria cepistipes is a common wood-rotting basidiomycete fungus found in most forests in Central Europe. In Switzerland, the habitat of A. cepistipes is fragmented because of the presence of major geographical barriers, in particular the Alps, and past deforestation. We analysed the impact of habitat fragmentation on the current spatial genetic structure of the Swiss A. cepistipes population. A total of 167 isolates were sampled across an area of 41 000 km(2) and genotyped at seven microsatellite and four single nucleotide polymorphism (SNP) loci. All isolates belonged to different genotypes which, according to the Bayesian clustering algorithm implemented in Tess, originated from a single gene pool. Our analyses indicate that the overall A. cepistipes population shows little, but significant (F(ST)=0.02), genetic differentiation. Such a situation suggests gene flow is strong, possibly due to long-distance dispersal of airborne basidiospores. This hypothesis is supported by the fact that we could not detect a pattern of isolation by distance. Gene flow is partially restricted by the high mountain ranges of the Alps, as indicated by a signal of spatial autocorrelation detected among genotypes separated by less than about 80-130 km. In contrast, past deforestation seems to have no significant effect on the current spatial population structure of A. cepistipes. This might indicate the existence of a time lag between the current spatial genetic structure and the processes that have induced this specific structure. PMID:22954341

  17. Breeding population density and habitat use of Swainson's warblers in a Georgia floodplain forest

    USGS Publications Warehouse

    Wright, E.A.

    2002-01-01

    I examined density and habitat use of a Swainson's Warbler (Limnothlypis swainsonii) breeding population in Georgia. This songbird species is inadequately monitored, and may be declining due to anthropogenic alteration of floodplain forest breeding habitats. I used distance sampling methods to estimate density, finding 9.4 singing males/ha (CV = 0.298). Individuals were encountered too infrequently to produce a Iow-variance estimate, and distance sampling thus may be impracticable for monitoring this relatively rare species. I developed a set of multivariate habitat models using binary logistic regression techniques, based on measurement of 22 variables in 56 plots occupied by Swainson's Warblers and 110 unoccupied plots. Occupied areas were characterized by high stem density of cane (Arundinaria gigantea) and other shrub layer vegetation, and presence of abundant and accessible leaf litter. I recommend two habitat models, which correctly classified 87-89% of plots in cross-validation runs, for potential use in habitat assessment at other locations.

  18. Comparing Population Patterns to Processes: Abundance and Survival of a Forest Salamander following Habitat Degradation

    PubMed Central

    Otto, Clint R. V.; Roloff, Gary J.; Thames, Rachael E.

    2014-01-01

    Habitat degradation resulting from anthropogenic activities poses immediate and prolonged threats to biodiversity, particularly among declining amphibians. Many studies infer amphibian response to habitat degradation by correlating patterns in species occupancy or abundance with environmental effects, often without regard to the demographic processes underlying these patterns. We evaluated how retention of vertical green trees (CANOPY) and coarse woody debris (CWD) influenced terrestrial salamander abundance and apparent survival in recently clearcut forests. Estimated abundance of unmarked salamanders was positively related to CANOPY (Canopy  = 0.21 (0.02–1.19; 95% CI), but not CWD (CWD  = 0.11 (−0.13–0.35) within 3,600 m2 sites, whereas estimated abundance of unmarked salamanders was not related to CANOPY (Canopy  = −0.01 (−0.21–0.18) or CWD (CWD  = −0.02 (−0.23–0.19) for 9 m2 enclosures. In contrast, apparent survival of marked salamanders within our enclosures over 1 month was positively influenced by both CANOPY and CWD retention (Canopy  = 0.73 (0.27–1.19; 95% CI) and CWD  = 1.01 (0.53–1.50). Our results indicate that environmental correlates to abundance are scale dependent reflecting habitat selection processes and organism movements after a habitat disturbance event. Our study also provides a cautionary example of how scientific inference is conditional on the response variable(s), and scale(s) of measure chosen by the investigator, which can have important implications for species conservation and management. Our research highlights the need for joint evaluation of population state variables, such as abundance, and population-level process, such as survival, when assessing anthropogenic impacts on forest biodiversity. PMID:24718498

  19. Decline and conservation of bumble bees.

    PubMed

    Goulson, D; Lye, G C; Darvill, B

    2008-01-01

    Declines in bumble bee species in the past 60 years are well documented in Europe, where they are driven primarily by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of bumble bees and their largely monogamous breeding system, which renders their effective population size low. Hence, populations are susceptible to stochastic extinction events and inbreeding. In North America, catastrophic declines of some bumble bee species since the 1990s are probably attributable to the accidental introduction of a nonnative parasite from Europe, a result of global trade in domesticated bumble bee colonies used for pollination of greenhouse crops. Given the importance of bumble bees as pollinators of crops and wildflowers, steps must be taken to prevent further declines. Suggested measures include tight regulation of commercial bumble bee use and targeted use of environmentally comparable schemes to enhance floristic diversity in agricultural landscapes. PMID:17803456

  20. Demographic consequences of population subdivision on the long-furred woolly mouse opossum ( Micoureus paraguayanus) from the Atlantic Forest

    NASA Astrophysics Data System (ADS)

    Brito, Daniel; da Fonseca, Gustavo A. B.

    2007-01-01

    Habitat destruction and fragmentation severely affected the Atlantic Forest. Formerly contiguous populations may become subdivided into a larger number of smaller populations, threatening their long-term persistence. The computer package VORTEX was used to simulate the consequences of habitat fragmentation and population subdivision on Micoureus paraguayanus, an endemic arboreal marsupial of the Atlantic Forest. Scenarios simulated hypothetical populations of 100 and 2000 animals being partitioned into 1-10 populations, linked by varying rates of inter-patch dispersal, and also evaluated male-biased dispersal. Results demonstrated that a single population was more stable than an ensemble of populations of equal size, irrespective of dispersal rate. Small populations (10-20 individuals) exhibited high instability due to demographic stochasticity, and were characterized by high rates of extinction, smaller values for metapopulation growth and larger fluctuations in population size and growth rate. Dispersal effects on metapopulation persistence were related to the size of the populations and to the sexes that were capable of dispersing. Male-biased dispersal had no noticeable effects on metapopulation extinction dynamics, whereas scenarios modelling dispersal by both sexes positively affected metapopulation dynamics through higher growth rates, smaller fluctuations in growth rate, larger final metapopulation sizes and lower probabilities of extinction. The present study highlights the complex relationships between metapopulation size, population subdivision, habitat fragmentation, rate of inter-patch dispersal and sex-biased dispersal and indicates the importance of gaining a better understanding of dispersal and its interactions with correlations between disturbance events.

  1. Sampling bee communities using pan traps: alternative methods increase sample size

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring of the status of bee populations and inventories of bee faunas require systematic sampling. Efficiency and ease of implementation has encouraged the use of pan traps to sample bees. Efforts to find an optimal standardized sampling method for pan traps have focused on pan trap color. Th...

  2. Changes in Patch Features May Exacerbate or Compensate for the Effect of Habitat Loss on Forest Bird Populations

    PubMed Central

    Magrach, Ainhoa; Larrinaga, Asier R.; Santamaría, Luis

    2011-01-01

    One and a half centuries after Darwin visited Chiloe Island, what he described as “…an island covered by one great forest…” has lost two-thirds of its forested areas. At this biodiversity hotspot, forest surface is becoming increasingly fragmented due to unregulated logging, clearing for pastures and replacement by exotic tree plantations. Decrease in patch size, increased isolation and “edge effects” can influence the persistence of forest species in remnant fragments. We assessed how these variables affect local density for six forest birds, chosen to include the most important seed dispersers (four species) and bird pollinators (two species, one of which acts also as seed disperser), plus the most common insectivore (Aphrastura spinicauda). Based on cue-count point surveys (8 points per fragment), we estimated bird densities for each species in 22 forest fragments of varying size, shape, isolation and internal-habitat structure (e.g. tree size and epiphyte cover). Bird densities varied with fragment connectivity (three species) and shape (three species), but none of the species was significantly affected by patch size. Satellite image analyses revealed that, from 1985 to 2008, forested area decreased by 8.8% and the remaining forest fragments became 16% smaller, 58–73% more isolated and 11–50% more regular. During that period, bird density estimates for the northern part of Chiloé (covering an area of 1214.75 km2) decreased for one species (elaenia), increased for another two (chucao and hummingbird) and did not vary for three (rayadito, thrust and blackbird). For the first three species, changes in patch features respectively exacerbated, balanced and overcame the effects of forest loss on bird population size (landscape-level abundance). Hence, changes in patch features can modulate the effect of habitat fragmentation on forest birds, suggesting that spatial planning (guided by spatially-explicit models) can be an effective tool to facilitate

  3. Effects of forest management on density, survival, and population growth of wood thrushes

    USGS Publications Warehouse

    Powell, L.A.; Lang, J.D.; Conroy, M.J.; Krementz, D.G.

    2000-01-01

    Loss and alteration of breeding habitat have been proposed as causes of declines in several Neotropical migrant bird populations. We conducted a 4-year study to determine the effects of winter prescribed burning and forest thinning on breeding wood thrush (Hylocichla mustelina) populations at the Piedmont National Wildlife Refuge (PNWR) in Georgia. We estimated density, adult and juvenile survival rates, and apparent annual survival using transect surveys, radiotelemetry, and mist netting. Burning and thinning did not cause lower densities (P = 0.25); wood thrush density ranged from 0.15 to 1.30 pairs/10 ha. No radiomarked male wood thrushes (n = 68) died during the 4 years, but female (n = 63) weekly survival was 0.981 ? 0.014 (SE) for females (n = 63) and 0.976 ? 0.010 for juveniles (n = 38). Apparent annual adult survival was 0.579 (SE = 0.173). Thinning and prescribed burning did not reduce adult or juvenile survival during the breeding season or apparent annual adult survival. Annual population growth (lambda) at PNWR was 1.00 (95% confidence interval = 0.32--1.63), and the considerable uncertainty in this prediction underscores the need for long term monitoring to effectively manage Neotropical migrants. Population growth increased on experimental compartments after the burn and thin (95% CI before = 0.91--0.97, after = 0.98--1.05), while control compartment declined (before = 0.98--1.05, after = 0.87--0.92). We found no evidence that the current management regime at PNWR, designed to improve red-cockaded woodpecker (Picoides borealis) habitat, negatively affected wood thrushes.

  4. Surveys of forest bird populations found in the vicinity of proposed geothermal project subzones in the district of Puna, Hawaii

    SciTech Connect

    Jacobi, J.D.; Reynolds, M.; Ritchotte, G.; Nielsen, B.; Viggiano, A.; Dwyer, J.

    1994-10-01

    This report presents data on the distribution and status of forest bird species found within the vicinity of proposed geothermal resource development on the Island of Hawaii. Potential impacts of the proposed development on the native bird populations found in the project are are addressed.

  5. Population dynamics of an invasive forest insect and associated natural enemies in the aftermath of invasion: implications for biological control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the population dynamics of exotic pests and associated natural enemies is important in developing sound management strategies in invaded forest ecosystems. The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an invasive phloem-feeding beetle that h...

  6. Tropical forest landscape dynamics: Population consequences for neotropical lianas, genus Passiflora

    NASA Astrophysics Data System (ADS)

    Plowes, Robert Merrick

    Treefall gaps in rainforest landscapes play a crucial role in providing opportunities for establishment and growth of rare, light-demanding plants such as Passifora vines in Corcovado rainforests, Costa Rica. This study considers the interplay of landscape dynamics with plant life history traits and strategies in an ephemeral patch network. In Chapter One, I show how patch quality dynamics and propagule dispersal affect colonization of treefall gaps by Passifora vitifolia. Recruitment required high patch quality, exceeding 3 hours of sunlight and patches closed after about 6 years. Colonization by seed dispersal (80%) was constrained by patch quality and isolation, while clonal growth from dormant plants (20%) was limited to rare adjacent patches. Since patch turnover is critical in these systems, Chapter Two is focused on factors affecting canopy structure. I showed that prior landuse altered the dynamics of frequent, small-scale disturbances during succession following a single, large deforestation event. Here, I used Landsat subpixel analysis, aerial photographs and field surveys to demonstrate major changes in dynamics of regenerating canopies following release from agricultural activity in 1975. Little work has considered the role of life history traits in persistence of patchy populations, and so in Chapter Three I asked what life history strategies are used by 9 Passiflora species that occur in these transient forest gaps. Although Passiflora species exhibited differences in dormancy or dispersal strategies, abundance was not associated with any one strategy. Elasticities of vital rates (stasis, growth and fecundity) of P. vitifolia differed empirically in old growth and regenerating forests. To explore population responses to changes in landscape parameters or life history strategies, I created a spatially-explicit individual-based model. Simulations indicate that plant types with a dormancy phase have a greater suite of responses since they persist after

  7. Population and habitat dynamics of the white-footed mouse (Peromyscus leucopus) in a heterogeneous forest

    SciTech Connect

    Ormiston, B.G.

    1984-07-01

    Movements and demography of white-footed mice (Peromyscus leucopus) were determined by live-trapping and radiotelemetry in contiguous upland and lowland forest habitat to assess the extent of variation in local habitat distribution due to season, age, and sex factors. Mice were marked and recaptured monthly in 1980 and 1981 from April through December on a continuous 20 ha trapping grid, thus yielding 1486 captures of 397 individuals. Locations and activity of 43 mice were determined by radiotracking. Various measures of habitat suitability, including adult density, sex ratio, reproduction, persistence, home range size, and immigration, indicated a seasonal cycle of habitat suitability. Upland habitat appeared better for overwintering, and lowland habitat was superior relative to the upland from June through October. Tendencies for breeding females to be restricted to lowland, and for lowland males to display greater mean body weights and smaller home range sizes than upland males, were attributed to greater food availability in the lowland over this period. Individual P. leucopus use local habitats opportunistically, but variations in habitat distribution between the age- and sex-classes of the population noted during the breeding season suggest that local habitats provide a spatial framework for behavioral population regulation in P. leucopus. 49 references, 5 figures, 10 tables.

  8. Widespread occurrence of honey bee pathogens in solitary bees.

    PubMed

    Ravoet, Jorgen; De Smet, Lina; Meeus, Ivan; Smagghe, Guy; Wenseleers, Tom; de Graaf, Dirk C

    2014-10-01

    Solitary bees and honey bees from a neighbouring apiary were screened for a broad set of putative pathogens including protists, fungi, spiroplasmas and viruses. Most sampled bees appeared to be infected with multiple parasites. Interestingly, viruses exclusively known from honey bees such as Apis mellifera Filamentous Virus and Varroa destructor Macula-like Virus were also discovered in solitary bees. A microsporidium found in Andrena vaga showed most resemblance to Nosema thomsoni. Our results suggest that bee hives represent a putative source of pathogens for other pollinators. Similarly, solitary bees may act as a reservoir of honey bee pathogens.

  9. Colonies of bumble bees (Bombus impatiens) produce fewer workers, less bee biomass, and have smaller mother queens following fungicide exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bees provide vital pollination services to the majority of flowering plants in both natural and agricultural systems. Unfortunately, both native and managed bee populations are experiencing serious declines, threatening the persistence of these plants and crops. Agricultural chemicals are one possib...

  10. [Relative abundance, population structure, habitat preferences and activity patterns of Tapirus bairdii (Perissodactyla: Tapiridae), in Chimalapas forest, Oaxaca, Mexico].

    PubMed

    Lira-Torres, Iván; Briones-Salas, Miguel; Sánchez-Rojas, Gerardo

    2014-12-01

    Baird's tapir (Tapirus bairdii) is endangered primarily because of habitat loss and fragmentation, and overhunting throughout its distribution range. One of the priority land areas for the conservation of this species is the Northern part of its range in the Chimalapas forest, Oaxaca. The aim of this research was to determine the relative abundance, population struc- ture, habitat preferences and activity patterns of Baird's tapir (Tapirus bairdii) in the Chimalapas forest, Oaxaca, Mexico, through the non-invasive technique of camera-trap sampling. A total of five sampling sessions were undertaken among 2009-2013, and used a total of 30 camera-traps in each period. The determinant factor of the sampling design was the hunting between two study areas. A total sampling effort of 9000 trap-days allowed to estimate an index of relative abundance (IRA) of 6.77 tapir photographs/1,000 trap-days (n = 61). IRA varied significantly between sampling stations (Mann-Whitney, p < 0.01). The frequency of Baird's tapir photos was higher in the dry season in tropical rain forest without hunting (χ2, p < 0.5). In the rainy season, the tropical rain forest and secondary vegetation habitats showed higher photo frequency than expected from random (χ2, p < 0.5). Considering population structure, a 95.08% of adult animals was obtained in photographic records (n = 58). Three types of activity pattern were observed, with more nocturnal records (88.33%; Kruskal-Wallis, p < 0.05). The Chimalapas forest appears to be the second most important terrestrial priority ecoregion, just after the Mayan Forest (Campeche, Chiapas, Quintana Roo), for the conservation of tapir populations, not only for Mexico but also for Central America. PMID:25720176

  11. [Relative abundance, population structure, habitat preferences and activity patterns of Tapirus bairdii (Perissodactyla: Tapiridae), in Chimalapas forest, Oaxaca, Mexico].

    PubMed

    Lira-Torres, Iván; Briones-Salas, Miguel; Sánchez-Rojas, Gerardo

    2014-12-01

    Baird's tapir (Tapirus bairdii) is endangered primarily because of habitat loss and fragmentation, and overhunting throughout its distribution range. One of the priority land areas for the conservation of this species is the Northern part of its range in the Chimalapas forest, Oaxaca. The aim of this research was to determine the relative abundance, population struc- ture, habitat preferences and activity patterns of Baird's tapir (Tapirus bairdii) in the Chimalapas forest, Oaxaca, Mexico, through the non-invasive technique of camera-trap sampling. A total of five sampling sessions were undertaken among 2009-2013, and used a total of 30 camera-traps in each period. The determinant factor of the sampling design was the hunting between two study areas. A total sampling effort of 9000 trap-days allowed to estimate an index of relative abundance (IRA) of 6.77 tapir photographs/1,000 trap-days (n = 61). IRA varied significantly between sampling stations (Mann-Whitney, p < 0.01). The frequency of Baird's tapir photos was higher in the dry season in tropical rain forest without hunting (χ2, p < 0.5). In the rainy season, the tropical rain forest and secondary vegetation habitats showed higher photo frequency than expected from random (χ2, p < 0.5). Considering population structure, a 95.08% of adult animals was obtained in photographic records (n = 58). Three types of activity pattern were observed, with more nocturnal records (88.33%; Kruskal-Wallis, p < 0.05). The Chimalapas forest appears to be the second most important terrestrial priority ecoregion, just after the Mayan Forest (Campeche, Chiapas, Quintana Roo), for the conservation of tapir populations, not only for Mexico but also for Central America.

  12. BeeDoctor, a Versatile MLPA-Based Diagnostic Tool for Screening Bee Viruses

    PubMed Central

    De Smet, Lina; Ravoet, Jorgen; de Miranda, Joachim R.; Wenseleers, Tom; Mueller, Matthias Y.; Moritz, Robin F. A.; de Graaf, Dirk C.

    2012-01-01

    The long-term decline of managed honeybee hives in the world has drawn significant attention to the scientific community and bee-keeping industry. A high pathogen load is believed to play a crucial role in this phenomenon, with the bee viruses being key players. Most of the currently characterized honeybee viruses (around twenty) are positive stranded RNA viruses. Techniques based on RNA signatures are widely used to determine the viral load in honeybee colonies. High throughput screening for viral loads necessitates the development of a multiplex polymerase chain reaction approach in which different viruses can be targeted simultaneously. A new multiparameter assay, called “BeeDoctor”, was developed based on multiplex-ligation probe dependent amplification (MLPA) technology. This assay detects 10 honeybee viruses in one reaction. “BeeDoctor” is also able to screen selectively for either the positive strand of the targeted RNA bee viruses or the negative strand, which is indicative for active viral replication. Due to its sensitivity and specificity, the MLPA assay is a useful tool for rapid diagnosis, pathogen characterization, and epidemiology of viruses in honeybee populations. “BeeDoctor” was used for screening 363 samples from apiaries located throughout Flanders; the northern half of Belgium. Using the “BeeDoctor”, virus infections were detected in almost eighty percent of the colonies, with deformed wing virus by far the most frequently detected virus and multiple virus infections were found in 26 percent of the colonies. PMID:23144717

  13. Influence of Mortality Factors and Host Resistance on the Population Dynamics of Emerald Ash Borer (Coleoptera: Buprestidae) in Urban Forests.

    PubMed

    Macquarrie, Chris J K; Scharbach, Roger

    2015-02-01

    The success of emerald ash borer (Agrilus planipennis Fairmaire) in North America is hypothesized to be due to both the lack of significant natural enemies permitting easy establishment and a population of trees that lack the ability to defend themselves, which allows populations to grow unchecked. Since its discovery in 2002, a number of studies have examined mortality factors of the insect in forests, but none have examined the role of natural enemies and other mortality agents in the urban forest. This is significant because it is in the urban forest where the emerald ash borer has had the most significant economic impacts. We studied populations in urban forests in three municipalities in Ontario, Canada, between 2010 and 2012 using life tables and stage-specific survivorship to analyze data from a split-rearing manipulative experiment. We found that there was little overall mortality caused by natural enemies; most mortality we did observe was caused by disease. Stage-specific survivorship was lowest in small and large larvae, supporting previous observations of high mortality in these two stages. We also used our data to test the hypothesis that mortality and density in emerald ash borer are linked. Our results support the prediction of a negative relationship between mortality and density. However, the relationship varies between insects developing in the crown and those in the trunk of the tree. This relationship was significant because when incorporated with previous findings, it suggests a mechanism and hypothesis to explain the outbreak dynamics of the emerald ash borer.

  14. Decline in Bee Diversity and Abundance from 1972-2004 in a Flowering Leguminous Tree, Andira inermis in Costa Rica at the Interface of Disturbed Dry Forest and the Urban Environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term monitoring of bees in specific sites provides information on changes in diversity and abundance, especially in areas close to human habitation. Evaluations of this monitoring data combined with relevant measures of anthropogenic activity can aide in interpreting emerging patterns of bee p...

  15. Calibrating abundance indices with population size estimators of red back salamanders (Plethodon cinereus) in a New England forest

    PubMed Central

    Ellison, Aaron M.; Jackson, Scott

    2015-01-01

    Herpetologists and conservation biologists frequently use convenient and cost-effective, but less accurate, abundance indices (e.g., number of individuals collected under artificial cover boards or during natural objects surveys) in lieu of more accurate, but costly and destructive, population size estimators to detect and monitor size, state, and trends of amphibian populations. Although there are advantages and disadvantages to each approach, reliable use of abundance indices requires that they be calibrated with accurate population estimators. Such calibrations, however, are rare. The red back salamander, Plethodon cinereus, is an ecologically useful indicator species of forest dynamics, and accurate calibration of indices of salamander abundance could increase the reliability of abundance indices used in monitoring programs. We calibrated abundance indices derived from surveys of P. cinereus under artificial cover boards or natural objects with a more accurate estimator of their population size in a New England forest. Average densities/m2 and capture probabilities of P. cinereus under natural objects or cover boards in independent, replicate sites at the Harvard Forest (Petersham, Massachusetts, USA) were similar in stands dominated by Tsuga canadensis (eastern hemlock) and deciduous hardwood species (predominantly Quercus rubra [red oak] and Acer rubrum [red maple]). The abundance index based on salamanders surveyed under natural objects was significantly associated with density estimates of P. cinereus derived from depletion (removal) surveys, but underestimated true density by 50%. In contrast, the abundance index based on cover-board surveys overestimated true density by a factor of 8 and the association between the cover-board index and the density estimates was not statistically significant. We conclude that when calibrated and used appropriately, some abundance indices may provide cost-effective and reliable measures of P. cinereus abundance that could

  16. Calibrating abundance indices with population size estimators of red back salamanders (Plethodon cinereus) in a New England forest.

    PubMed

    Siddig, Ahmed A; Ellison, Aaron M; Jackson, Scott

    2015-01-01

    Herpetologists and conservation biologists frequently use convenient and cost-effective, but less accurate, abundance indices (e.g., number of individuals collected under artificial cover boards or during natural objects surveys) in lieu of more accurate, but costly and destructive, population size estimators to detect and monitor size, state, and trends of amphibian populations. Although there are advantages and disadvantages to each approach, reliable use of abundance indices requires that they be calibrated with accurate population estimators. Such calibrations, however, are rare. The red back salamander, Plethodon cinereus, is an ecologically useful indicator species of forest dynamics, and accurate calibration of indices of salamander abundance could increase the reliability of abundance indices used in monitoring programs. We calibrated abundance indices derived from surveys of P. cinereus under artificial cover boards or natural objects with a more accurate estimator of their population size in a New England forest. Average densities/m(2) and capture probabilities of P. cinereus under natural objects or cover boards in independent, replicate sites at the Harvard Forest (Petersham, Massachusetts, USA) were similar in stands dominated by Tsuga canadensis (eastern hemlock) and deciduous hardwood species (predominantly Quercus rubra [red oak] and Acer rubrum [red maple]). The abundance index based on salamanders surveyed under natural objects was significantly associated with density estimates of P. cinereus derived from depletion (removal) surveys, but underestimated true density by 50%. In contrast, the abundance index based on cover-board surveys overestimated true density by a factor of 8 and the association between the cover-board index and the density estimates was not statistically significant. We conclude that when calibrated and used appropriately, some abundance indices may provide cost-effective and reliable measures of P. cinereus abundance that

  17. A Field Experiment to Assess the Rate of Infestation in Honey Bee Populations of Two Metarhizium anisopliae Isolates on Varroa destructor (Acari: Mesostigmata)

    PubMed Central

    Pirali-kheirabadi, Khodadad; Teixeira-da-Silva, Jaime A; Razzaghi-Abyaneh, Mehdi; Nazemnia, Mehdi

    2013-01-01

    Background: The protective effect of two isolates of an entomopathogenic fungus, Metarhizium anisopliae (DEMI 002 and Iran 437C) on the adult stage of Varroa destructor was evaluated in comparison with fluvalinate strips in the field. Methods: A total of 12 honey bee colonies were provided from an apiculture farm. The selected hives were divided into 4 groups (3 hives per group). The first group was the control, treated with distilled water. The other two groups were exposed to different fungi (M. anisopliae isolates DEMI 002 and Iran 437C) and the last group was treated with one strip of fluvalinate per colony. The number of fallen mites was counted using sticky traps during a 6-day period, six days before and after treatments. A fungal suspension at a concentration of 5× 106 conidia/mL was sprayed onto the frames and the number of fallen mites was counted. Results: Metarhizium anisopliae DEMI 002 and Iran 437C isolates were as effective (i.e., caused as much mite fall) as the fluvalinate strip in controlling bee colonies than no treatment. Conclusion: Both M. anisopliae isolates are promising candidates as agents in the control of Varroa mites under field conditions. Isolate DEMI 002 can be considered as a possible non-chemical biocontrol agent for controlling bee infestation with V. destructor in the field. In order to substantiate this hypothesis, tests are currently being performed using larger colonies and larger doses than tested in the present study in our beekeeping. PMID:23785691

  18. Environment or kin: whence do bees obtain acidophilic bacteria?

    PubMed

    McFrederick, Quinn S; Wcislo, William T; Taylor, Douglas R; Ishak, Heather D; Dowd, Scot E; Mueller, Ulrich G

    2012-04-01

    As honey bee populations decline, interest in pathogenic and mutualistic relationships between bees and microorganisms has increased. Honey bees and bumble bees appear to have a simple intestinal bacterial fauna that includes acidophilic bacteria. Here, we explore the hypothesis that sweat bees can acquire acidophilic bacteria from the environment. To quantify bacterial communities associated with two species of North American and one species of Neotropical sweat bees, we conducted 16S rDNA amplicon 454 pyrosequencing of bacteria associated with the bees, their brood cells and their nests. Lactobacillus spp. were the most abundant bacteria in many, but not all, of the samples. To determine whether bee-associated lactobacilli can also be found in the environment, we reconstructed the phylogenetic relationships of the genus Lactobacillus. Previously described groups that associate with Bombus and Apis appeared relatively specific to these genera. Close relatives of several bacteria that have been isolated from flowers, however, were isolated from bees. Additionally, all three sweat bee species associated with lactobacilli related to flower-associated lactobacilli. These data suggest that there may be at least two different means by which bees acquire putative probiotics. Some lactobacilli appear specific to corbiculate apids, possibly because they are largely maternally inherited (vertically transmitted). Other lactobacilli, however, may be regularly acquired from environmental sources such as flowers. Sweat bee-associated lactobacilli were found to be abundant in the pollen and frass inside the nests of halictids, suggesting that they could play a role in suppressing the growth of moulds and other spoilage organisms.

  19. Role of edge effect on small mammal populations in a forest fragment

    SciTech Connect

    Wike, L.D.

    2000-06-27

    In many cases, edge effect may determine the distribution and densities of small mammal populations. In 1995 and 1998, a mark and recapture study was conducted at the Savannah River Site (SRS), Aiken, SC, to evaluate the role of forest edge habitat. The area studied was an abandoned home site that had been recently isolated by a timber harvest. Harvest activities left a distinct edge of old field and planted pine contrasting with a relatively xeric, mixed hardwood stand. Trapping was conducted for 17 days in 1995 and 14 days in 1998. Three 30 m by 150 m grids were placed in the clear-cut, edge, and hardwood interior habitats. For both years the principal species captured were Peromyscus gossypinus, P. polionotus, and Neotoma floridana. The edge habitat accounted for approximately 55 percent of all captures and nearly four times as many recaptures as the interior and clear-cut habitats. In 1998, greater numbers of N. floridana were trapped than in 1995. The results indicate that the use of edge habitat can be pronounced even within simple communities. Stewards of managed or restored habitats need to carefully consider the role of edge in these systems. In managed areas such as waste sites, movement of material within the food chain could be reduced by minimizing edge habitat around the points of contamination.

  20. Selective of informative metabolites using random forests based on model population analysis.

    PubMed

    Huang, Jian-Hua; Yan, Jun; Wu, Qing-Hua; Duarte Ferro, Miguel; Yi, Lun-Zhao; Lu, Hong-Mei; Xu, Qing-Song; Liang, Yi-Zeng

    2013-12-15

    One of the main goals of metabolomics studies is to discover informative metabolites or biomarkers, which may be used to diagnose diseases and to find out pathology. Sophisticated feature selection approaches are required to extract the information hidden in such complex 'omics' data. In this study, it is proposed a new and robust selective method by combining random forests (RF) with model population analysis (MPA), for selecting informative metabolites from three metabolomic datasets. According to the contribution to the classification accuracy, the metabolites were classified into three kinds: informative, no-informative, and interfering metabolites. Based on the proposed method, some informative metabolites were selected for three datasets; further analyses of these metabolites between healthy and diseased groups were then performed, showing by T-test that the P values for all these selected metabolites were lower than 0.05. Moreover, the informative metabolites identified by the current method were demonstrated to be correlated with the clinical outcome under investigation. The source codes of MPA-RF in Matlab can be freely downloaded from http://code.google.com/p/my-research-list/downloads/list. PMID:24209380

  1. Impacts of Austrian Climate Variability on Honey Bee Mortality

    NASA Astrophysics Data System (ADS)

    Switanek, Matt; Brodschneider, Robert; Crailsheim, Karl; Truhetz, Heimo

    2015-04-01

    Global food production, as it is today, is not possible without pollinators such as the honey bee. It is therefore alarming that honey bee populations across the world have seen increased mortality rates in the last few decades. The challenges facing the honey bee calls into question the future of our food supply. Beside various infectious diseases, Varroa destructor is one of the main culprits leading to increased rates of honey bee mortality. Varroa destructor is a parasitic mite which strongly depends on honey bee brood for reproduction and can wipe out entire colonies. However, climate variability may also importantly influence honey bee breeding cycles and bee mortality rates. Persistent weather events affects vegetation and hence foraging possibilities for honey bees. This study first defines critical statistical relationships between key climate indicators (e.g., precipitation and temperature) and bee mortality rates across Austria, using 6 consecutive years of data. Next, these leading indicators, as they vary in space and time, are used to build a statistical model to predict bee mortality rates and the respective number of colonies affected. Using leave-one-out cross validation, the model reduces the Root Mean Square Error (RMSE) by 21% with respect to predictions made with the mean mortality rate and the number of colonies. Furthermore, a Monte Carlo test is used to establish that the model's predictions are statistically significant at the 99.9% confidence level. These results highlight the influence of climate variables on honey bee populations, although variability in climate, by itself, cannot fully explain colony losses. This study was funded by the Austrian project 'Zukunft Biene'.

  2. Contrasting effects of mass-flowering crops on bee pollination of hedge plants at different spatial and temporal scales.

    PubMed

    Kovács-Hostyánszki, Anikó; Haenke, Sebastian; Batáry, Péter; Jauker, Birgit; Báldi, András; Tscharntke, Teja; Holzschuh, Andrea

    2013-12-01

    Landscape-wide mass-flowering of oilseed rape (canola Brassica napus) can considerably affect wild bee communities and pollination success of wild plants. We aimed to assess the impact of oilseed rape on the pollination of wild plants and bee abundance during and after oilseed-rape bloom, including effects on crop-noncrop spillover at landscape and adjacent-field scales. We focused on two shrub species (hawthorn Crataegus spp., dog rose Rosa canina) and adjacent herb flowering in forest edges, connected hedges, and isolated hedges in Lower Saxony, Germany. We selected 35 landscape circles of 1 km radius, differing in the amount of oilseed rape; 18 were adjacent to oilseed rape and 17 to cereal fields, and we quantified bee density via pan traps at all sites. Adjacent oilseed rape positively affected fruit mass and seed number per fruit of simultaneously flowering hawthorn (no effect on dog rose, which flowers after the oilseed rape bloom). At the landscape scale, oilseed rape had a negative effect on bumble bee density in the hedges during flowering due to dilution of pollinators per unit area and the consequently intensified competition between oilseed rape and wild shrubs, but a positive effect after flowering when bees moved to the hedges, which still provided resources. In contrast, positive landscape-scale effects of oilseed rape were found throughout the season in forest edges, suggesting that edges support nesting activity and enhanced food resources. Our results show that oilseed rape effects on bee abundances and pollination success in seminatural habitats depend on the spatial and temporal scale considered and on the habitat type, the wild plant species, and the time of crop flowering. These scale-dependent positive and negative effects should be considered in evaluations of landscape-scale configuration and composition of crops. Food resources provided by mass-flowering crops should be most beneficial for landscape-wide enhancement of wild bee

  3. Contrasting effects of mass-flowering crops on bee pollination of hedge plants at different spatial and temporal scales.

    PubMed

    Kovács-Hostyánszki, Anikó; Haenke, Sebastian; Batáry, Péter; Jauker, Birgit; Báldi, András; Tscharntke, Teja; Holzschuh, Andrea

    2013-12-01

    Landscape-wide mass-flowering of oilseed rape (canola Brassica napus) can considerably affect wild bee communities and pollination success of wild plants. We aimed to assess the impact of oilseed rape on the pollination of wild plants and bee abundance during and after oilseed-rape bloom, including effects on crop-noncrop spillover at landscape and adjacent-field scales. We focused on two shrub species (hawthorn Crataegus spp., dog rose Rosa canina) and adjacent herb flowering in forest edges, connected hedges, and isolated hedges in Lower Saxony, Germany. We selected 35 landscape circles of 1 km radius, differing in the amount of oilseed rape; 18 were adjacent to oilseed rape and 17 to cereal fields, and we quantified bee density via pan traps at all sites. Adjacent oilseed rape positively affected fruit mass and seed number per fruit of simultaneously flowering hawthorn (no effect on dog rose, which flowers after the oilseed rape bloom). At the landscape scale, oilseed rape had a negative effect on bumble bee density in the hedges during flowering due to dilution of pollinators per unit area and the consequently intensified competition between oilseed rape and wild shrubs, but a positive effect after flowering when bees moved to the hedges, which still provided resources. In contrast, positive landscape-scale effects of oilseed rape were found throughout the season in forest edges, suggesting that edges support nesting activity and enhanced food resources. Our results show that oilseed rape effects on bee abundances and pollination success in seminatural habitats depend on the spatial and temporal scale considered and on the habitat type, the wild plant species, and the time of crop flowering. These scale-dependent positive and negative effects should be considered in evaluations of landscape-scale configuration and composition of crops. Food resources provided by mass-flowering crops should be most beneficial for landscape-wide enhancement of wild bee

  4. Population structure and spatial pattern of main tree species in secondary Betula platyphylla forest in Ziwuling Mountains, China.

    PubMed

    Kang, Di; Guo, Yaoxin; Ren, Chengjie; Zhao, Fazhu; Feng, Yongzhong; Han, Xinhui; Yang, Gaihe

    2014-01-01

    This study investigated a typical secondary Betula platyphylla forest in the Ziwuling Mountains, Loess Plateau, China. In the sample plot, the DBH (diameter at breast height) class structure of B. platyphylla was bimodal. Individuals with small and large DBH values were abundant. The DBH structures of Quercus wutaishanica and Pinus tabulaeformis were close to that of the logistic model, thus suggesting the increasing population of these species. B. platyphylla and Populus davidiana showed random spatial distributions at almost all scales. However, Q. wutaishanica and P. tabulaeformis were significantly clumped at small scales. B. platyphylla had a negative spatial relation with Q. wutaishanica at small spatial scales. P. tabulaeformis and Q. wutaishanica showed negative spatial correlations at small scales, but they had positive correlations at large scales. These results suggest that P. tabulaeformis and Q. wutaishanica shared habitat preferences at these scales. In the future, the secondary B. platyphylla forest in the Ziwuling Mountains in the Loess Plateau will probably change into a multi-species mixed forest (Quercus-Pinus mixed forest). Assisted restoration strategies must be employed to improve the regeneration dynamics of the forest in the long term. PMID:25362993

  5. Diversity and abundance of orchid bees (Hymenoptera: Apidae, Euglossini) in a tropical rainforest succession.

    PubMed

    Rasmussen, Claus

    2009-01-01

    Euglossine bee males are easily lured to chemical baits imitating natural fragrances gathered by bees, providing a widely applied measure for estimating the diversity and abundance of euglossines. In here, I report the composition of euglossine bees in three lowland rainforest habitats of Peru, a primary old forest, a reforested and managed forest, and a very disturbed forest. A total of 2,072 males of euglossine were collected, belonging to 33 species and four genera. Although a comparable diversity relative to other studies from the Amazonian region was found, no significant differences among the sampled areas were detected. Perhaps, the short time and low intensity surveys here used (< 3 months) were not good enough indicators of forest disturbance without additional data. Compared to other major studies on the euglossine bee fauna, Loreto is most similar to the species assemblage reported from lowland rainforest in Brazil (Manaus), central Peru (Panguana) and southern Peru (Tambopata). PMID:19347098

  6. Forest fragments as barriers to fruit fly dispersal: Anastrepha (Diptera: Tephritidae) populations in orchards and adjacent forest fragments in Puerto Rico.

    PubMed

    Jenkins, David A; Kendra, Paul E; Van Bloem, Skip; Whitmire, Stefanie; Mizell, Russ; Goenaga, Ricardo

    2013-04-01

    McPhail-type traps baited with ammonium acetate and putrescine were used to monitor populations of Anastrepha obliqua (Macquart) and Anastrepha suspensa (Loew) in two orchards with hosts of these flies (mango, Mangifera indica L., and carambola, Averrhoa carambola L.), as well as in forest fragments bordering these orchards. Contour maps were constructed to measure population distributions in and around orchards. Our results indicate that Anastrepha populations are focused around host fruit in both space and time, that traps do not draw fruit flies away from hosts, even when placed within 15 m of the host, and that lures continue to function for 6 mo in the field. The contour mapping analyses reveal that populations of fruit flies are focused around ovipositional hosts. Although the trapping system does not have a very long effective sampling range, it is ideal, when used in combination with contour analyses, for assessing fine-scale (on the order of meters) population distributions, including identifying resources around which fly populations are focused or, conversely, assessing the effectiveness of management tools. The results are discussed as they pertain to monitoring and detecting Anastrepha spp. with the McPhail-type trap and ammonium acetate and putrescine baiting system and the dispersal of these flies within Puerto Rico.

  7. Efficacy of hand-broadcast application of baits containing 0.005% diphacinone in reducing rat populations in Hawaiian forests

    USGS Publications Warehouse

    Foote, David; Lindsey, Gerald D.; Perry, Charlotte F.; Spurr, Eric

    2013-01-01

    Introduced black rats (Rattus rattus), Polynesian rats (R. exulans/i>), and Norway rats (R. norvegicus) impact insular bird, plant, and invertebrate populations worldwide. We investigated the efficacy of hand-broadcast application of Ramik® Green containing 0.005% diphacinone for rodent control in paired 4-ha treatment and non-treatment plots in both wet and mesic forest in Hawaiʽi. Radio telemetry of black rats, the predominant species, indicated 100% mortality in both treatment plots within about one week of bait application. Live trapping and non-toxic census bait block monitoring two to four weeks after each of 12 repeat bait applications in the wet forest, and three repeat bait applications in the mesic forest, indicated rat abundance was reduced on average by 84–88%. However, reinvasion could have occurred within this time. Rat populations in the treatment plots usually recovered to pre-poison levels within two to five months. House mice (Mus musculus), Indian mongooses (Herpestes auropunctatus), and feral cats (Felis catus) also ate bait or other animals that had eaten bait. This study demonstrates the efficacy of ground-based broadcast toxicant baits for the control of rats in Hawaiian montane wet forests.

  8. [Biodiversity of tree species, their populations' spatial distribution pattern and interspecific association in mixed deciduous broadleaved forest in Changbai Mountains].

    PubMed

    Guo, Zhongling; Ma, Yuandan; Zheng, Jiping; Liu, Wande; Jin, Zefeng

    2004-11-01

    Based on the data collected from the sampling plot with an area of 1 hm2 at the Experimental and Management Bureau of Jiaohe in Jilin Province, this paper analyzed and researched the community structure, biological diversity, spatial distribution pattern and interspecific association between tree species populations in a mixed deciduous broadleaved forest. The results indicated that there was no obvious dominant order among tree species populations, and the indices of tree species diversity such as Shannon-Wiener index (H'), Pielou evenness index (E) and Simpson ecological dominant index (D) were all low. Shrub and herb species diversity indices were also not high. The spatial distribution pattern of five dominant tree species all presented aggregative. Based on 2 x 2 contigency table, the interspecific associations of 15 tree species in the community were examined by means of chi2-test, together with the association coefficient (AC). The results showed that there were 14 species pairs in 15 species showing significantly negative association. The proportion of species pairs showing negative association was much more than that of showing positive association. It could be deduced that the community was instable and at the stage of autogenic succession from soft deciduous broadleaved forest to hard deciduous broadleaved forest, and then, the Korean pine broadleaved forest.

  9. One World: Service Bees

    ERIC Educational Resources Information Center

    Thomason, Rhonda

    2009-01-01

    Bees are a vital part of the ecology. People of conscience are a vital part of society. In Nina Frenkel's "One World" poster, the bee is also a metaphor for the role of the individual in a diverse society. This article presents a lesson that uses Frenkel's poster to help early-grades students connect these ideas and explore both the importance of…

  10. Honey bee toxicology.

    PubMed

    Johnson, Reed M

    2015-01-01

    Insecticides are chemicals used to kill insects, so it is unsurprising that many insecticides have the potential to harm honey bees (Apis mellifera). However, bees are exposed to a great variety of other potentially toxic chemicals, including flavonoids and alkaloids that are produced by plants; mycotoxins produced by fungi; antimicrobials and acaricides that are introduced by beekeepers; and fungicides, herbicides, and other environmental contaminants. Although often regarded as uniquely sensitive to toxic compounds, honey bees are adapted to tolerate and even thrive in the presence of toxic compounds that occur naturally in their environment. The harm caused by exposure to a particular concentration of a toxic compound may depend on the level of simultaneous exposure to other compounds, pathogen levels, nutritional status, and a host of other factors. This review takes a holistic view of bee toxicology by taking into account the spectrum of xenobiotics to which bees are exposed. PMID:25341092

  11. Honey bee toxicology.

    PubMed

    Johnson, Reed M

    2015-01-01

    Insecticides are chemicals used to kill insects, so it is unsurprising that many insecticides have the potential to harm honey bees (Apis mellifera). However, bees are exposed to a great variety of other potentially toxic chemicals, including flavonoids and alkaloids that are produced by plants; mycotoxins produced by fungi; antimicrobials and acaricides that are introduced by beekeepers; and fungicides, herbicides, and other environmental contaminants. Although often regarded as uniquely sensitive to toxic compounds, honey bees are adapted to tolerate and even thrive in the presence of toxic compounds that occur naturally in their environment. The harm caused by exposure to a particular concentration of a toxic compound may depend on the level of simultaneous exposure to other compounds, pathogen levels, nutritional status, and a host of other factors. This review takes a holistic view of bee toxicology by taking into account the spectrum of xenobiotics to which bees are exposed.

  12. Phenotypic variation in fitness traits of a managed solitary bee, Osmia ribifloris (Hymenoptera: Megachilidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Captive bee populations are useful for modeling the genetic and ecological factors regulating the size of small natural pollinator populations. We assessed population trends, brood size, and mortality rates for captive generations of a mason bee, Osmia ribifloris, whose parents came from Texas (TX),...

  13. Museum specimens reveal loss of pollen host plants as key factor driving wild bee decline in The Netherlands.

    PubMed

    Scheper, Jeroen; Reemer, Menno; van Kats, Ruud; Ozinga, Wim A; van der Linden, Giel T J; Schaminée, Joop H J; Siepel, Henk; Kleijn, David

    2014-12-01

    Evidence for declining populations of both wild and managed bees has raised concern about a potential global pollination crisis. Strategies to mitigate bee loss generally aim to enhance floral resources. However, we do not really know whether loss of preferred floral resources is the key driver of bee decline because accurate assessment of host plant preferences is difficult, particularly for species that have become rare. Here we examine whether population trends of wild bees in The Netherlands can be explained by trends in host plants, and how this relates to other factors such as climate change. We determined host plant preference of bee species using pollen loads on specimens in entomological collections that were collected before the onset of their decline, and used atlas data to quantify population trends of bee species and their host plants. We show that decline of preferred host plant species was one of two main factors associated with bee decline. Bee body size, the other main factor, was negatively related to population trend, which, because larger bee species have larger pollen requirements than smaller species, may also point toward food limitation as a key factor driving wild bee loss. Diet breadth and other potential factors such as length of flight period or climate change sensitivity were not important in explaining twentieth century bee population trends. These results highlight the species-specific nature of wild bee decline and indicate that mitigation strategies will only be effective if they target the specific host plants of declining species.

  14. Museum specimens reveal loss of pollen host plants as key factor driving wild bee decline in The Netherlands

    PubMed Central

    Scheper, Jeroen; Reemer, Menno; van Kats, Ruud; Ozinga, Wim A.; van der Linden, Giel T. J.; Schaminée, Joop H. J.; Siepel, Henk; Kleijn, David

    2014-01-01

    Evidence for declining populations of both wild and managed bees has raised concern about a potential global pollination crisis. Strategies to mitigate bee loss generally aim to enhance floral resources. However, we do not really know whether loss of preferred floral resources is the key driver of bee decline because accurate assessment of host plant preferences is difficult, particularly for species that have become rare. Here we examine whether population trends of wild bees in The Netherlands can be explained by trends in host plants, and how this relates to other factors such as climate change. We determined host plant preference of bee species using pollen loads on specimens in entomological collections that were collected before the onset of their decline, and used atlas data to quantify population trends of bee species and their host plants. We show that decline of preferred host plant species was one of two main factors associated with bee decline. Bee body size, the other main factor, was negatively related to population trend, which, because larger bee species have larger pollen requirements than smaller species, may also point toward food limitation as a key factor driving wild bee loss. Diet breadth and other potential factors such as length of flight period or climate change sensitivity were not important in explaining twentieth century bee population trends. These results highlight the species-specific nature of wild bee decline and indicate that mitigation strategies will only be effective if they target the specific host plants of declining species. PMID:25422416

  15. Museum specimens reveal loss of pollen host plants as key factor driving wild bee decline in The Netherlands.

    PubMed

    Scheper, Jeroen; Reemer, Menno; van Kats, Ruud; Ozinga, Wim A; van der Linden, Giel T J; Schaminée, Joop H J; Siepel, Henk; Kleijn, David

    2014-12-01

    Evidence for declining populations of both wild and managed bees has raised concern about a potential global pollination crisis. Strategies to mitigate bee loss generally aim to enhance floral resources. However, we do not really know whether loss of preferred floral resources is the key driver of bee decline because accurate assessment of host plant preferences is difficult, particularly for species that have become rare. Here we examine whether population trends of wild bees in The Netherlands can be explained by trends in host plants, and how this relates to other factors such as climate change. We determined host plant preference of bee species using pollen loads on specimens in entomological collections that were collected before the onset of their decline, and used atlas data to quantify population trends of bee species and their host plants. We show that decline of preferred host plant species was one of two main factors associated with bee decline. Bee body size, the other main factor, was negatively related to population trend, which, because larger bee species have larger pollen requirements than smaller species, may also point toward food limitation as a key factor driving wild bee loss. Diet breadth and other potential factors such as length of flight period or climate change sensitivity were not important in explaining twentieth century bee population trends. These results highlight the species-specific nature of wild bee decline and indicate that mitigation strategies will only be effective if they target the specific host plants of declining species. PMID:25422416

  16. [Species composition and main populations spatial distribution pattern in Korean pine broadleaved forest in Xiaoxing' An Mountains of Northeast China].

    PubMed

    Hou, Hong-Ya; Wang, Li-Hai

    2013-11-01

    Taking the Korean pine broadleaved forest in Liangshui Nature Reserve of Heilongjiang Province, Northeast China as test object, this paper studied the species composition and diameter class structure, and by using point pattern analysis, analyzed the spatial distribution pattern and spatial association of the main populations. In the Reserve, there were a total of 16 species with diameter greater than 1 cm in tree layer, and great differences were observed in the densities of main populations. Coniferous trees such as Pinus koraiensis and Abies nephrolepis were dominant. The diameter class structure of the populations presented as an inverse "J" curve, indicating a good regeneration across the community. The main populations were mostly in aggregated distribution pattern, except that the P. koraiensis populations at the scales of 19-21 m and 44 m as well as the Acer tegmentosum populations close to the largest research scale were in random distribution. The P. koraiensis populations at all research scales were approximately in random distribution, and had the minimum aggregation. A. nephrolepis, Tilia amurensis, and A. tegmentosum populations all presented a random distribution trend. Except that the P. koraiensis and A. nephrolepis at 2-3 m scale and the A. nephrolepis and A. tegmentosum populations at 37-81 m scale had significant positive association, no significant associations were observed between other populations. All the tree species presented an overall non-significant positive association. PMID:24564130

  17. Species composition, community and population dynamics of two gallery forests from the Brazilian Cerrado domain

    PubMed Central

    Almado, Roosevelt P; Miazaki, Angela S; Diniz, Écio S; Moreira, Luis C B; Meira-Neto, João A.A.

    2016-01-01

    Abstract Background To understand the impacts of global changes on future community compositions, knowledge of community dynamics is of crucial importance. To improve our knowledge of community composition, biomass stock and maintenance of gallery forests in the Brazilian Cerrado, we provide two datasets from the 0.5 ha Corrego Fazendinha Gallery Forest Dynamics Plot and the Corrego Fundo Gallery Forest Dynamics Plot situated in the Bom Despacho region, Minas Gerais, Southeastern Brazil. New information We report diameter at breast height, basal area and height measurements of 3417 trees and treelets identified during three censuses in both areas.

  18. Species composition, community and population dynamics of two gallery forests from the Brazilian Cerrado domain

    PubMed Central

    Almado, Roosevelt P; Miazaki, Angela S; Diniz, Écio S; Moreira, Luis C B; Meira-Neto, João A.A.

    2016-01-01

    Abstract Background To understand the impacts of global changes on future community compositions, knowledge of community dynamics is of crucial importance. To improve our knowledge of community composition, biomass stock and maintenance of gallery forests in the Brazilian Cerrado, we provide two datasets from the 0.5 ha Corrego Fazendinha Gallery Forest Dynamics Plot and the Corrego Fundo Gallery Forest Dynamics Plot situated in the Bom Despacho region, Minas Gerais, Southeastern Brazil. New information We report diameter at breast height, basal area and height measurements of 3417 trees and treelets identified during three censuses in both areas. PMID:27660529

  19. Vicariance and marine migration in continental island populations of a frog endemic to the Atlantic Coastal forest

    PubMed Central

    Duryea, M C; Zamudio, K R; Brasileiro, C A

    2015-01-01

    The theory of island biogeography is most often studied in the context of oceanic islands where all island inhabitants are descendants from founding events involving migration from mainland source populations. Far fewer studies have considered predictions of island biogeography in the case of continental islands, where island formation typically splits continuous populations and thus vicariance also contributes to the diversity of island populations. We examined one such case on continental islands in southeastern Brazil, to determine how classic island biogeography predictions and past vicariance explain the population genetic diversity of Thoropa taophora, a frog endemic to the Atlantic Coastal Forest. We used nuclear microsatellite markers to examine the genetic diversity of coastal and island populations of this species. We found that island isolation has a role in shaping the genetic diversity of continental island species, with island populations being significantly less diverse than coastal populations. However, area of the island and distance from coast had no significant effect on genetic diversity. We also found no significant differences between migration among coastal populations and migration to and from islands. We discuss how vicariance and the effects of continued migration between coastal and island populations interact to shape evolutionary patterns on continental islands. PMID:25920672

  20. Vicariance and marine migration in continental island populations of a frog endemic to the Atlantic Coastal forest.

    PubMed

    Duryea, M C; Zamudio, K R; Brasileiro, C A

    2015-09-01

    The theory of island biogeography is most often studied in the context of oceanic islands where all island inhabitants are descendants from founding events involving migration from mainland source populations. Far fewer studies have considered predictions of island biogeography in the case of continental islands, where island formation typically splits continuous populations and thus vicariance also contributes to the diversity of island populations. We examined one such case on continental islands in southeastern Brazil, to determine how classic island biogeography predictions and past vicariance explain the population genetic diversity of Thoropa taophora, a frog endemic to the Atlantic Coastal Forest. We used nuclear microsatellite markers to examine the genetic diversity of coastal and island populations of this species. We found that island isolation has a role in shaping the genetic diversity of continental island species, with island populations being significantly less diverse than coastal populations. However, area of the island and distance from coast had no significant effect on genetic diversity. We also found no significant differences between migration among coastal populations and migration to and from islands. We discuss how vicariance and the effects of continued migration between coastal and island populations interact to shape evolutionary patterns on continental islands.

  1. Stochastically generating tree diameter lists to populate forest stands based on the linkage variables, forest type and stand age.

    SciTech Connect

    Parresol, B.R.; Lloyd, F.T.

    2003-08-31

    Forest inventory data were used to develop a stand-age-driven, stochastic predictor of unit-area, frequency-weighted lists of breast high tree diameters (DBH). The average of mean statistics from 40-simulation prediction sets of an independent 78-plot validation dataset differed from the observed validation means by 0.5 cm for DBH, and by 12 trees/h for density. The 40-simulation average of standard deviation, quartile range, maximum value and minimum value differed from the validation dataset, respectively, by 0.3, 1.3, 0.6 and 1.5 cm for DBH, and 10, 42, 29, and 54 trees/h for density. In addition, test statistics were also computed individually for each of the 40 single simulations of the 78-plot validation dataset. In all cases, the test statistics supported the null hypothesis of no difference between simulated and observed DBH lists. When power of these hypothesis test statistics was set to 80%, the calculated minimum detectable differences were still reasonably small at 2.7 cm for mean DBH and 90 trees/h for stocking. Also, the shape and dispersion of simulated mean-DBH/density scatter graphs were similar to the same scatter graph from the observed, validation dataset.

  2. Pesticides and reduced-risk insecticides, native bees and pantropical stingless bees: pitfalls and perspectives.

    PubMed

    Barbosa, Wagner F; Smagghe, Guy; Guedes, Raul Narciso C

    2015-08-01

    Although invertebrates generally have a low public profile, the honey bee, Apis mellifera L., is a flagship species whose popularity likely derives from the products it provides and its perceived ecological services. Therefore, the raging debate regarding honey bee decline has surpassed the realm of beekeepers, academia, industry and regulatory agencies and now also encompasses non-governmental agencies, media, fiction writers and the general public. The early interest and concern about honey bee colony collapse disorder (CCD) soon shifted to the bigger issue of pollinator decline, with a focus on the potential involvement of pesticides in such a phenomenon. Pesticides were previously recognised as the potential culprits of the reported declines, particularly the neonicotinoid insecticides owing to their widespread and peculiar use in agriculture. However, the evidence for the potential pivotal role of these neonicotinoids in honey bee decline remains a matter of debate, with an increased recognition of the multifactorial nature of the problem and the lack of a direct association between the noted decline and neonicotinoid use. The focus on the decline of honey bee populations subsequently spread to other species, and bumblebees became another matter of concern, particularly in Europe and the United States. Other bee species, ones that are particularly important in other regions of the world, remain the object of little concern (unjustifiably so). Furthermore, the continuous focus on neonicotinoids is also in need of revision, as the current evidence suggests that a broad spectrum of compounds deserve attention. Here we address both shortcomings.

  3. Pesticides and reduced-risk insecticides, native bees and pantropical stingless bees: pitfalls and perspectives.

    PubMed

    Barbosa, Wagner F; Smagghe, Guy; Guedes, Raul Narciso C

    2015-08-01

    Although invertebrates generally have a low public profile, the honey bee, Apis mellifera L., is a flagship species whose popularity likely derives from the products it provides and its perceived ecological services. Therefore, the raging debate regarding honey bee decline has surpassed the realm of beekeepers, academia, industry and regulatory agencies and now also encompasses non-governmental agencies, media, fiction writers and the general public. The early interest and concern about honey bee colony collapse disorder (CCD) soon shifted to the bigger issue of pollinator decline, with a focus on the potential involvement of pesticides in such a phenomenon. Pesticides were previously recognised as the potential culprits of the reported declines, particularly the neonicotinoid insecticides owing to their widespread and peculiar use in agriculture. However, the evidence for the potential pivotal role of these neonicotinoids in honey bee decline remains a matter of debate, with an increased recognition of the multifactorial nature of the problem and the lack of a direct association between the noted decline and neonicotinoid use. The focus on the decline of honey bee populations subsequently spread to other species, and bumblebees became another matter of concern, particularly in Europe and the United States. Other bee species, ones that are particularly important in other regions of the world, remain the object of little concern (unjustifiably so). Furthermore, the continuous focus on neonicotinoids is also in need of revision, as the current evidence suggests that a broad spectrum of compounds deserve attention. Here we address both shortcomings. PMID:25892651

  4. Influence of Mortality Factors and Host Resistance on the Population Dynamics of Emerald Ash Borer (Coleoptera: Buprestidae) in Urban Forests.

    PubMed

    Macquarrie, Chris J K; Scharbach, Roger

    2015-02-01

    The success of emerald ash borer (Agrilus planipennis Fairmaire) in North America is hypothesized to be due to both the lack of significant natural enemies permitting easy establishment and a population of trees that lack the ability to defend themselves, which allows populations to grow unchecked. Since its discovery in 2002, a number of studies have examined mortality factors of the insect in forests, but none have examined the role of natural enemies and other mortality agents in the urban forest. This is significant because it is in the urban forest where the emerald ash borer has had the most significant economic impacts. We studied populations in urban forests in three municipalities in Ontario, Canada, between 2010 and 2012 using life tables and stage-specific survivorship to analyze data from a split-rearing manipulative experiment. We found that there was little overall mortality caused by natural enemies; most mortality we did observe was caused by disease. Stage-specific survivorship was lowest in small and large larvae, supporting previous observations of high mortality in these two stages. We also used our data to test the hypothesis that mortality and density in emerald ash borer are linked. Our results support the prediction of a negative relationship between mortality and density. However, the relationship varies between insects developing in the crown and those in the trunk of the tree. This relationship was significant because when incorporated with previous findings, it suggests a mechanism and hypothesis to explain the outbreak dynamics of the emerald ash borer. PMID:26308819

  5. Complex Spatial Structure in a Population of Didymopanax pittieri, A Tree of Wind-Exposed Lower Montane Rain Forest

    NASA Technical Reports Server (NTRS)

    Lawton, Robert M.; Lawton, Robert O.

    2010-01-01

    Didymopanax pittieri is a common shade-intolerant tree colonizing treefall gaps in the elfin forests on windswept ridgecrests in the lower montane rain forests of the Cordillera de Tilarain, Costa Rica. All D. pittieri taller than > 0.5 m in a 5.2-ha elfin forested portion of a gridded study watershed in the Monteverde Cloud Forest Preserve were located, mapped, and measured. This local population of D. pittieri is spatially inhomogeneous, in that density increases with increasing wind exposure; D. pittieri are more abundant near ridge crests than lower on windward slopes. The important and ubiquitous phenomenon of spatial inhomogeneity in population density is addressed and corrected for in spatial analyses by the application of the inhomogeneous version of Ripley's K. The spatial patterns of four size classes of D. pittieri (<5 cm dbh, 5-10 cm dbh, 10-20 cm dbh, and> 20 cm dbh) were investigated. Within the large-scale trend in density driven by wind exposure, D. pittieri saplings are clumped at the scale of treefall gaps and at the scale of patches of aggregated gaps. D. pittieri 5-10 cm dbh are randomly distributed, apparently due to competitive thinning of sapling clumps during the early stages of gap-phase regeneration. D. pittieri larger than 10 cm dbh are overdispersed at a scale larger than that of patches of gaps. Natural disturbance can influence the distribution of shade intolerant tree populations at several different spatial scales, and can have discordant effects at different life history stages.

  6. Chronic sublethal stress causes bee colony failure.

    PubMed

    Bryden, John; Gill, Richard J; Mitton, Robert A A; Raine, Nigel E; Jansen, Vincent A A

    2013-12-01

    Current bee population declines and colony failures are well documented yet poorly understood and no single factor has been identified as a leading cause. The evidence is equivocal and puzzling: for instance, many pathogens and parasites can be found in both failing and surviving colonies and field pesticide exposure is typically sublethal. Here, we investigate how these results can be due to sublethal stress impairing colony function. We mathematically modelled stress on individual bees which impairs colony function and found how positive density dependence can cause multiple dynamic outcomes: some colonies fail while others thrive. We then exposed bumblebee colonies to sublethal levels of a neonicotinoid pesticide. The dynamics of colony failure, which we observed, were most accurately described by our model. We argue that our model can explain the enigmatic aspects of bee colony failures, highlighting an important role for sublethal stress in colony declines.

  7. Chronic sublethal stress causes bee colony failure.

    PubMed

    Bryden, John; Gill, Richard J; Mitton, Robert A A; Raine, Nigel E; Jansen, Vincent A A

    2013-12-01

    Current bee population declines and colony failures are well documented yet poorly understood and no single factor has been identified as a leading cause. The evidence is equivocal and puzzling: for instance, many pathogens and parasites can be found in both failing and surviving colonies and field pesticide exposure is typically sublethal. Here, we investigate how these results can be due to sublethal stress impairing colony function. We mathematically modelled stress on individual bees which impairs colony function and found how positive density dependence can cause multiple dynamic outcomes: some colonies fail while others thrive. We then exposed bumblebee colonies to sublethal levels of a neonicotinoid pesticide. The dynamics of colony failure, which we observed, were most accurately described by our model. We argue that our model can explain the enigmatic aspects of bee colony failures, highlighting an important role for sublethal stress in colony declines. PMID:24112478

  8. Chronic sublethal stress causes bee colony failure

    PubMed Central

    Bryden, John; Gill, Richard J; Mitton, Robert A A; Raine, Nigel E; Jansen, Vincent A A; Hodgson, David

    2013-01-01

    Current bee population declines and colony failures are well documented yet poorly understood and no single factor has been identified as a leading cause. The evidence is equivocal and puzzling: for instance, many pathogens and parasites can be found in both failing and surviving colonies and field pesticide exposure is typically sublethal. Here, we investigate how these results can be due to sublethal stress impairing colony function. We mathematically modelled stress on individual bees which impairs colony function and found how positive density dependence can cause multiple dynamic outcomes: some colonies fail while others thrive. We then exposed bumblebee colonies to sublethal levels of a neonicotinoid pesticide. The dynamics of colony failure, which we observed, were most accurately described by our model. We argue that our model can explain the enigmatic aspects of bee colony failures, highlighting an important role for sublethal stress in colony declines. PMID:24112478

  9. Modeling interactions betweenspotted owl and barred owl populations in fire-prone forests

    EPA Science Inventory

    Background / Question / Methods Efforts to conserve northern spotted owls (Strix occidentalis caurina) in the eastern Cascades of Washington must merge the challenges of providing sufficient structurally complex forest habitat in a fire-prone landscape with the limitations impos...

  10. A stingless bee can use visual odometry to estimate both height and distance.

    PubMed

    Eckles, M A; Roubik, D W; Nieh, J C

    2012-09-15

    Bees move and forage within three dimensions and rely heavily on vision for navigation. The use of vision-based odometry has been studied extensively in horizontal distance measurement, but not vertical distance measurement. The honey bee Apis mellifera and the stingless bee Melipona seminigra measure distance visually using optic flow-movement of images as they pass across the retina. The honey bees gauge height using image motion in the ventral visual field. The stingless bees forage at different tropical forest canopy levels, ranging up to 40 m at our site. Thus, estimating height would be advantageous. We provide the first evidence that the stingless bee Melipona panamica utilizes optic flow information to gauge not only distance traveled but also height above ground, by processing information primarily from the lateral visual field. After training bees to forage at a set height in a vertical tunnel lined with black and white stripes, we observed foragers that explored a new tunnel with no feeder. In a new tunnel, bees searched at the same height they were trained to. In a narrower tunnel, bees experienced more image motion and significantly lowered their search height. In a wider tunnel, bees experienced less image motion and searched at significantly greater heights. In a tunnel without optic cues, bees were disoriented and searched at random heights. A horizontal tunnel testing these variables similarly affected foraging, but bees exhibited less precision (greater variance in search positions). Accurately gauging flight height above ground may be crucial for this species and others that compete for resources located at heights ranging from ground level to the high tropical forest canopies.

  11. A population estimate of blue-eyed black lemurs in Ankarafa Forest, Sahamalaza-Iles Radama National Park, Madagascar.

    PubMed

    Volampeno, M Sylviane N; Masters, Judith C; Downs, Colleen T

    2010-01-01

    The critically endangered blue-eyed black lemur (Eulemur flavifrons) has one of the smallest distributions of any lemur, occurring only in the north-western forests of Madagascar. We report the results of a population estimate of this taxon in part of the Ankarafa Forest, Sahamalaza-Iles Radama National Park, a dry deciduous forest. We collected data between September 2007 and February 2008 using a total count method with marked individuals and known groups. In all, 228 individuals comprising 29 groups were counted. Group sizes ranged from 4 to 11 individuals with a mean of 8 ± 1.8. We estimated population density to be 1.0 individual/ha or 97.3 individuals/km(2) for our study area, which is higher than previous estimates reported for Ankarafa and other sites within the Sahamalaza Peninsula. Our mean group size, however, was similar to those determined in previous studies. Both group size and density of the blue-eyed black lemur were higher within the National Park than in previous studies outside the Park.

  12. [Effects of thinning intensities on population regeneration of natural Quercus variabilis forest on the south slope of Qinling Mountains].

    PubMed

    Ran, Ran; Zhang, Wen-Hui; He, Jing-Feng; Zhou, Jian-Yun

    2014-03-01

    Taking the natural Quercus variabilis forest in Shangluo, south slope of Qinling Mountains as the object in May 2006 and August 2011, which was under close-to-natural management of different thinning intensities (30%, 20%, 10%), and the un-thinned forest as the control, changes of the stand growth situation before and after thinning, population regeneration, species diversity and soil fertility after 5 years of thinning were analyzed, and the effects of thinning on forestland revegetation and community development were evaluated comprehensively. The results showed that the number of 1-6 years old Q. variabilis seedlings increased with increasing thinning intensity, while no significant difference was found for above 6 years old seedlings. The regeneration potentials of population under 10%, 20% and 30% thinning were respectively increased by 10.8%, 28.5% and 32.9% compared with the control. Thinning promoted the DBH and crown of the trees and shrubs, as well as the height of shrubs, especially for light-loving plants, and the effect of promotion increased with increasing thinning intensity. The species diversity and soil fertility were improved after thinning, in order of 30% > 20% > 10% > control. The thinning intensity of 30% (canopy density 0.6) was more conducive to the continuable development of the natural Q. variabilis forest in which canopy density was above 0.85. PMID:24984485

  13. Chalkbrood transmission in the alfalfa leafcutting bee: the impact of disinfecting bee cocoons in loose cell management systems.

    PubMed

    James, R R

    2011-08-01

    Understanding pathogen transmission could illuminate new methods for disease prevention. A case in point is chalkbrood in the alfalfa leafcutting bee [Megachile rotundata (F.)]. Propagation of this solitary bee is severely hampered by chalkbrood, a larval disease caused by Ascosphaera aggregata (Ascomycota). Alfalfa leafcutting bees nest in existing cavities in wood or hollow reeds and overwinter as larvae. In the early summer, emerging adults frequently must chew through dead, diseased siblings that block their exit, becoming contaminated with chalkbrood spores in the process. When alfalfa leafcutting bees are used as a commercial pollinator, the cocoons are removed from nesting boards to reduce chalkbrood transmission, but the disease is still common. To determine if these removed cocoons (called loose cells) are an important source of disease transmission, they were disinfected with a fungicide before bees were incubated, and released in the field. Chalkbrood prevalence among the progeny of the treated bees was reduced up to 50% in one field trial, but not significantly when tested in an on-farm trial. Thus, substantial disease transmission still occurred when the loose cells were disinfected, and even when clean nesting materials were used. In conclusion, pathogen transmission must still be occurring from another source that has yet to be identified. Another possible source of transmission could arise from bees that emerge midsummer in populations with a high percent of multivoltinism, but dirty nesting boards and feral bees also may be minor sources of transmission. PMID:22251678

  14. Estimating the population density of the Asian tapir (Tapirus indicus) in a selectively logged forest in Peninsular Malaysia.

    PubMed

    Rayan, D Mark; Mohamad, Shariff Wan; Dorward, Leejiah; Aziz, Sheema Abdul; Clements, Gopalasamy Reuben; Christopher, Wong Chai Thiam; Traeholt, Carl; Magintan, David

    2012-12-01

    The endangered Asian tapir (Tapirus indicus) is threatened by large-scale habitat loss, forest fragmentation and increased hunting pressure. Conservation planning for this species, however, is hampered by a severe paucity of information on its ecology and population status. We present the first Asian tapir population density estimate from a camera trapping study targeting tigers in a selectively logged forest within Peninsular Malaysia using a spatially explicit capture-recapture maximum likelihood based framework. With a trap effort of 2496 nights, 17 individuals were identified corresponding to a density (standard error) estimate of 9.49 (2.55) adult tapirs/100 km(2) . Although our results include several caveats, we believe that our density estimate still serves as an important baseline to facilitate the monitoring of tapir population trends in Peninsular Malaysia. Our study also highlights the potential of extracting vital ecological and population information for other cryptic individually identifiable animals from tiger-centric studies, especially with the use of a spatially explicit capture-recapture maximum likelihood based framework. PMID:23253368

  15. Estimating the population density of the Asian tapir (Tapirus indicus) in a selectively logged forest in Peninsular Malaysia.

    PubMed

    Rayan, D Mark; Mohamad, Shariff Wan; Dorward, Leejiah; Aziz, Sheema Abdul; Clements, Gopalasamy Reuben; Christopher, Wong Chai Thiam; Traeholt, Carl; Magintan, David

    2012-12-01

    The endangered Asian tapir (Tapirus indicus) is threatened by large-scale habitat loss, forest fragmentation and increased hunting pressure. Conservation planning for this species, however, is hampered by a severe paucity of information on its ecology and population status. We present the first Asian tapir population density estimate from a camera trapping study targeting tigers in a selectively logged forest within Peninsular Malaysia using a spatially explicit capture-recapture maximum likelihood based framework. With a trap effort of 2496 nights, 17 individuals were identified corresponding to a density (standard error) estimate of 9.49 (2.55) adult tapirs/100 km(2) . Although our results include several caveats, we believe that our density estimate still serves as an important baseline to facilitate the monitoring of tapir population trends in Peninsular Malaysia. Our study also highlights the potential of extracting vital ecological and population information for other cryptic individually identifiable animals from tiger-centric studies, especially with the use of a spatially explicit capture-recapture maximum likelihood based framework.

  16. Floral biology of two Vanilloideae (Orchidaceae) primarily adapted to pollination by euglossine bees.

    PubMed

    Pansarin, E R; Pansarin, L M

    2014-11-01

    Vanilloideae comprises 15 genera distributed worldwide, among which are Vanilla and Epistephium (tribe Vanilleae). Based on field and laboratory investigations, the pollination biology of V. dubia and E. sclerophyllum was analysed. The former was surveyed in a semi-deciduous mesophytic forest at the biological reserve of Serra do Japi and in a marshy forest at the city of Pradópolis, southeastern Brazil. The latter was examined in rocky outcrop vegetation in the Chapada Diamantina, northeastern Brazil. In the studied populations, the tubular flowers of V. dubia and E. sclerophyllum were pollinated by bees. Pollen was deposited on either their scutellum (V. dubia) or scutum (E. sclerophyllum). The mentum region of V. dubia is dry, whereas that of E. sclerophyllum presents a small quantity of dilute nectar. Flowers of E. sclerophyllum are scentless, while those of V. dubia are odoriferous. Although V. dubia is self-compatible, it needs a pollinator to produce fruit. In contrast, E. sclerophyllum sets fruit through spontaneous self-pollination, but biotic pollination also occurs. Both species are primarily adapted to pollination by euglossine bees. Pollination by Euglossina seems to have occurred at least twice during the evolution of Vanilleae. Furthermore, shifts between rewarding and reward-free flowers and between autogamous and allogamous species have been reported among vanillas.

  17. Signature of a pre-human population decline in the critically endangered Reunion Island endemic forest bird Coracina newtoni.

    PubMed

    Salmona, Jordi; Salamolard, Marc; Fouillot, Damien; Ghestemme, Thomas; Larose, Jerry; Centon, Jean-François; Sousa, Vitor; Dawson, Deborah A; Thebaud, Christophe; Chikhi, Lounès

    2012-01-01

    The exceptional biodiversity of Reunion Island is threatened by anthropogenic landscape changes that took place during the 350 years of human colonization. During this period the human population size increased dramatically from 250 to 800,000. The arrival of humans together with the development of agriculture, invasive species such as rats and cats, and deforestation has lead to the extinction of more than half of the original vertebrate species of the island. For the remaining species, significant work is being carried out to identify threats and conservation status, but little genetic work has been carried on some of the most endangered species. In the last decade theoretical studies have shown the ability of neutral genetic markers to infer the demographic history of endangered species and identify and date past population size changes (expansions or bottlenecks). In this study we provide the first genetic data on the critically endangered species the Reunion cuckoo-shrike Coracina newtoni. The Reunion cuckoo-shrike is a rare endemic forest bird surviving in a restricted 12-km(2) area of forested uplands and mountains. The total known population consists of less than one hundred individuals out of which 45 were genotyped using seventeen polymorphic microsatellite loci. We found a limited level of genetic variability and weak population structure, probably due to the limited geographic distribution. Using Bayesian methods, we identified a strong decline in population size during the Holocene, most likely caused by an ancient climatic or volcanic event around 5000 years ago. This result was surprising as it appeared in apparent contradiction with the accepted theory of recent population collapse due to deforestation and predator introduction. These results suggest that new methods allowing for more complex demographic models are necessary to reconstruct the demographic history of populations.

  18. Signature of a Pre-Human Population Decline in the Critically Endangered Reunion Island Endemic Forest Bird Coracina newtoni

    PubMed Central

    Salmona, Jordi; Salamolard, Marc; Fouillot, Damien; Ghestemme, Thomas; Larose, Jerry; Centon, Jean-François; Sousa, Vitor; Dawson, Deborah A.; Thebaud, Christophe; Chikhi, Lounès

    2012-01-01

    The exceptional biodiversity of Reunion Island is threatened by anthropogenic landscape changes that took place during the 350 years of human colonization. During this period the human population size increased dramatically from 250 to 800,000. The arrival of humans together with the development of agriculture, invasive species such as rats and cats, and deforestation has lead to the extinction of more than half of the original vertebrate species of the island. For the remaining species, significant work is being carried out to identify threats and conservation status, but little genetic work has been carried on some of the most endangered species. In the last decade theoretical studies have shown the ability of neutral genetic markers to infer the demographic history of endangered species and identify and date past population size changes (expansions or bottlenecks). In this study we provide the first genetic data on the critically endangered species the Reunion cuckoo-shrike Coracina newtoni. The Reunion cuckoo-shrike is a rare endemic forest bird surviving in a restricted 12-km2 area of forested uplands and mountains. The total known population consists of less than one hundred individuals out of which 45 were genotyped using seventeen polymorphic microsatellite loci. We found a limited level of genetic variability and weak population structure, probably due to the limited geographic distribution. Using Bayesian methods, we identified a strong decline in population size during the Holocene, most likely caused by an ancient climatic or volcanic event around 5000 years ago. This result was surprising as it appeared in apparent contradiction with the accepted theory of recent population collapse due to deforestation and predator introduction. These results suggest that new methods allowing for more complex demographic models are necessary to reconstruct the demographic history of populations. PMID:22916272

  19. EXTERIOR VIEW, LOOKING WEST, AT FORMER TCIUS STEEL COMPANY BEE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR VIEW, LOOKING WEST, AT FORMER TCI-US STEEL COMPANY BEE HIVE OVEN RUINS WITH FORESTED OVERGROWTH. - Pratt Coal & Coke Company, Pratt Mines, Coke Ovens & Railroad, Bounded by First Street, Avenue G, Third Place, Birmingham Southern Railroad, Birmingham, Jefferson County, AL

  20. Variability in fruit and seed morphology among and within populations of Plathymenia (Leguminosae-Mimosoideae) in areas of the Cerrado, the Atlantic forest, and transitional sites.

    PubMed

    Goulart, M Figueiredo; Pires Lemos Filho, J; Lovato, M B

    2006-01-01

    Plathymenia reticulata is a tree species that occurs in two different Brazilian biomes, the Cerrado (a savannah environment), and the Atlantic Forest. In the present study, we evaluated morphological variation within and among five populations located in these vegetation types and in transitional sites in order to test the hypothesis that habitat selective pressures, being different in the Cerrado and the Atlantic Forest, would cause adaptive differences in morphological traits in individuals occurring under these different circumstances. Thirteen morphological traits of fruits, seeds, and of the membranous endocarp were obtained from 30 fruits and 20 seeds from each of nine to 10 individuals per population. Significant variation was found for all traits while comparing individuals within populations, and most traits varied significantly among populations as well. Some traits differed significantly between forest and Cerrado populations, while transition sites showed intermediate patterns and higher within-population variation. Contrary to our hypothesis, variation in seed size and mass among populations from different habitats was not significant. However, as predicted, the membranous endocarp was shorter for the seeds from Cerrado populations than from the Atlantic Forest. These data suggest the existence of P. reticulata ecotypes from Cerrado and Atlantic Forest; the relevance to Plathymenia evolution and to its wide ecological distribution is discussed.

  1. The power and promise of applying genomics to honey bee health

    PubMed Central

    Robinson, Gene E.

    2015-01-01

    New genomic tools and resources are now being used to both understand honey bee health and develop tools to better manage it. Here, we describe the use of genomic approaches to identify and characterize bee parasites and pathogens, examine interactions among these parasites and pathogens, between them and their bee hosts, and to identify genetic markers for improved breeding of more resilient bee stocks. We also discuss several new genomic techniques that can be used to more efficiently study, monitor and improve bee health. In the case of using RNAi-based technologies to mitigate diseases in bee populations, we highlight advantages, disadvantages and strategies to reduce risk. The increased use of genomic analytical tools and manipulative technologies has already led to significant advances, and holds great promise for improvements in the health of honey bees and other critical pollinator species. PMID:26273565

  2. Agrochemical-induced stress in stingless bees: peculiarities, underlying basis, and challenges.

    PubMed

    Lima, M A P; Martins, G F; Oliveira, E E; Guedes, R N C

    2016-10-01

    The toxicological stress induced by pesticides, particularly neonicotinoid insecticides, and its consequences in bees has been the focus of much recent attention, particularly for honey bees. However, the emphasis on honey bees and neonicotinoids has led to neglect of the relevance of stingless bees, the prevailing pollinators of natural and agricultural tropical ecosystems, and of other agrochemicals, including other pesticides and even leaf fertilizers. Consequently, studies focusing on agrochemical effects on stingless bees are sparse, usually limited to histopathological studies, and lack a holistic assessment of the effects of these compounds on physiology and behavior. Such effects have consequences for individual and colony fitness and are likely to affect both the stingless bee populations and the associated community, thereby producing a hierarchy of consequences thus far overlooked. Herein, we review the current literature on stingless bee-agrochemical interactions and discuss the underlying mechanisms involved in reported stress symptoms, as well as the potential consequences based on the peculiarities of these pollinators.

  3. A Buzzing Bee.

    ERIC Educational Resources Information Center

    Donovan, Edward P.; Barnes, Eb

    1996-01-01

    Presents an activity enabling students of grades four to nine to construct a "Buzzing Bee" model using simple materials. Provides students with the opportunity to explore the concepts of sound and the Doppler effect. (MKR)

  4. Parasite Pressures on Feral Honey Bees (Apis mellifera sp.)

    PubMed Central

    Thompson, Catherine E.; Biesmeijer, Jacobus C.; Allnutt, Theodore R.; Pietravalle, Stéphane; Budge, Giles E.

    2014-01-01

    Feral honey bee populations have been reported to be in decline due to the spread of Varroa destructor, an ectoparasitic mite that when left uncontrolled leads to virus build-up and colony death. While pests and diseases are known causes of large-scale managed honey bee colony losses, no studies to date have considered the wider pathogen burden in feral colonies, primarily due to the difficulty in locating and sampling colonies, which often nest in inaccessible locations such as church spires and tree tops. In addition, little is known about the provenance of feral colonies and whether they represent a reservoir of Varroa tolerant material that could be used in apiculture. Samples of forager bees were collected from paired feral and managed honey bee colonies and screened for the presence of ten honey bee pathogens and pests using qPCR. Prevalence and quantity was similar between the two groups for the majority of pathogens, however feral honey bees contained a significantly higher level of deformed wing virus than managed honey bee colonies. An assessment of the honey bee race was completed for each colony using three measures of wing venation. There were no apparent differences in wing morphometry between feral and managed colonies, suggesting feral colonies could simply be escapees from the managed population. Interestingly, managed honey bee colonies not treated for Varroa showed similar, potentially lethal levels of deformed wing virus to that of feral colonies. The potential for such findings to explain the large fall in the feral population and the wider context of the importance of feral colonies as potential pathogen reservoirs is discussed. PMID:25126840

  5. Parasite pressures on feral honey bees (Apis mellifera sp.).

    PubMed

    Thompson, Catherine E; Biesmeijer, Jacobus C; Allnutt, Theodore R; Pietravalle, Stéphane; Budge, Giles E

    2014-01-01

    Feral honey bee populations have been reported to be in decline due to the spread of Varroa destructor, an ectoparasitic mite that when left uncontrolled leads to virus build-up and colony death. While pests and diseases are known causes of large-scale managed honey bee colony losses, no studies to date have considered the wider pathogen burden in feral colonies, primarily due to the difficulty in locating and sampling colonies, which often nest in inaccessible locations such as church spires and tree tops. In addition, little is known about the provenance of feral colonies and whether they represent a reservoir of Varroa tolerant material that could be used in apiculture. Samples of forager bees were collected from paired feral and managed honey bee colonies and screened for the presence of ten honey bee pathogens and pests using qPCR. Prevalence and quantity was similar between the two groups for the majority of pathogens, however feral honey bees contained a significantly higher level of deformed wing virus than managed honey bee colonies. An assessment of the honey bee race was completed for each colony using three measures of wing venation. There were no apparent differences in wing morphometry between feral and managed colonies, suggesting feral colonies could simply be escapees from the managed population. Interestingly, managed honey bee colonies not treated for Varroa showed similar, potentially lethal levels of deformed wing virus to that of feral colonies. The potential for such findings to explain the large fall in the feral population and the wider context of the importance of feral colonies as potential pathogen reservoirs is discussed. PMID:25126840

  6. The First Estimates of Marbled Cat Pardofelis marmorata Population Density from Bornean Primary and Selectively Logged Forest

    PubMed Central

    Hearn, Andrew J.; Ross, Joanna; Bernard, Henry; Bakar, Soffian Abu; Hunter, Luke T. B.; Macdonald, David W.

    2016-01-01

    The marbled cat Pardofelis marmorata is a poorly known wild cat that has a broad distribution across much of the Indomalayan ecorealm. This felid is thought to exist at low population densities throughout its range, yet no estimates of its abundance exist, hampering assessment of its conservation status. To investigate the distribution and abundance of marbled cats we conducted intensive, felid-focused camera trap surveys of eight forest areas and two oil palm plantations in Sabah, Malaysian Borneo. Study sites were broadly representative of the range of habitat types and the gradient of anthropogenic disturbance and fragmentation present in contemporary Sabah. We recorded marbled cats from all forest study areas apart from a small, relatively isolated forest patch, although photographic detection frequency varied greatly between areas. No marbled cats were recorded within the plantations, but a single individual was recorded walking along the forest/plantation boundary. We collected sufficient numbers of marbled cat photographic captures at three study areas to permit density estimation based on spatially explicit capture-recapture analyses. Estimates of population density from the primary, lowland Danum Valley Conservation Area and primary upland, Tawau Hills Park, were 19.57 (SD: 8.36) and 7.10 (SD: 1.90) individuals per 100 km2, respectively, and the selectively logged, lowland Tabin Wildlife Reserve yielded an estimated density of 10.45 (SD: 3.38) individuals per 100 km2. The low detection frequencies recorded in our other survey sites and from published studies elsewhere in its range, and the absence of previous density estimates for this felid suggest that our density estimates may be from the higher end of their abundance spectrum. We provide recommendations for future marbled cat survey approaches. PMID:27007219

  7. The First Estimates of Marbled Cat Pardofelis marmorata Population Density from Bornean Primary and Selectively Logged Forest.

    PubMed

    Hearn, Andrew J; Ross, Joanna; Bernard, Henry; Bakar, Soffian Abu; Hunter, Luke T B; Macdonald, David W

    2016-01-01

    The marbled cat Pardofelis marmorata is a poorly known wild cat that has a broad distribution across much of the Indomalayan ecorealm. This felid is thought to exist at low population densities throughout its range, yet no estimates of its abundance exist, hampering assessment of its conservation status. To investigate the distribution and abundance of marbled cats we conducted intensive, felid-focused camera trap surveys of eight forest areas and two oil palm plantations in Sabah, Malaysian Borneo. Study sites were broadly representative of the range of habitat types and the gradient of anthropogenic disturbance and fragmentation present in contemporary Sabah. We recorded marbled cats from all forest study areas apart from a small, relatively isolated forest patch, although photographic detection frequency varied greatly between areas. No marbled cats were recorded within the plantations, but a single individual was recorded walking along the forest/plantation boundary. We collected sufficient numbers of marbled cat photographic captures at three study areas to permit density estimation based on spatially explicit capture-recapture analyses. Estimates of population density from the primary, lowland Danum Valley Conservation Area and primary upland, Tawau Hills Park, were 19.57 (SD: 8.36) and 7.10 (SD: 1.90) individuals per 100 km2, respectively, and the selectively logged, lowland Tabin Wildlife Reserve yielded an estimated density of 10.45 (SD: 3.38) individuals per 100 km2. The low detection frequencies recorded in our other survey sites and from published studies elsewhere in its range, and the absence of previous density estimates for this felid suggest that our density estimates may be from the higher end of their abundance spectrum. We provide recommendations for future marbled cat survey approaches.

  8. Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?

    USGS Publications Warehouse

    Welsh, H.H.; Fellers, G.M.; Lind, A.J.

    2007-01-01

    Amphibian declines have been documented worldwide; however the vast majority are species associated with aquatic habitats. Information on the status and trends of terrestrial amphibians is almost entirely lacking. Here we use data collected across a 12-yr period (sampling from 1984-86 and from 1993-95) to address the question of whether evidence exists for declines among terrestrial amphibians in northwestern California forests. The majority of amphibians, both species and relative numbers, in these forests are direct-developing salamanders of the family Plethodontidae. We examined amphibian richness and evenness, and the relative abundances of the four most common species of plethodontid salamanders. We examined evidence of differences between years in two ecological provinces (coastal and interior) and across young, mature, and late seral forests and with reference to a moisture gradient from xeric to hydric within late seral forests. We found evidence of declines in species richness across years on late seral mesic stands and in the coastal ecological province, but these differences appeared to be caused by differences in the detection of rarer species, rather than evidence of an overall pattern. We also found differences among specific years in numbers of individuals of the most abundant species, Ensatina eschscholtzii, but these differences also failed to reflect a consistent pattern of declines between the two decadal sample periods. Results showing differences in richness, evenness, and relative abundances along both the seral and moisture continua were consistent with previous research. Overall, we found no compelling evidence of a downward trend in terrestrial plethodontid salamanders. We believe that continued monitoring of terrestrial salamander populations is important to understanding mechanisms of population declines in amphibian species. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  9. The First Estimates of Marbled Cat Pardofelis marmorata Population Density from Bornean Primary and Selectively Logged Forest.

    PubMed

    Hearn, Andrew J; Ross, Joanna; Bernard, Henry; Bakar, Soffian Abu; Hunter, Luke T B; Macdonald, David W

    2016-01-01

    The marbled cat Pardofelis marmorata is a poorly known wild cat that has a broad distribution across much of the Indomalayan ecorealm. This felid is thought to exist at low population densities throughout its range, yet no estimates of its abundance exist, hampering assessment of its conservation status. To investigate the distribution and abundance of marbled cats we conducted intensive, felid-focused camera trap surveys of eight forest areas and two oil palm plantations in Sabah, Malaysian Borneo. Study sites were broadly representative of the range of habitat types and the gradient of anthropogenic disturbance and fragmentation present in contemporary Sabah. We recorded marbled cats from all forest study areas apart from a small, relatively isolated forest patch, although photographic detection frequency varied greatly between areas. No marbled cats were recorded within the plantations, but a single individual was recorded walking along the forest/plantation boundary. We collected sufficient numbers of marbled cat photographic captures at three study areas to permit density estimation based on spatially explicit capture-recapture analyses. Estimates of population density from the primary, lowland Danum Valley Conservation Area and primary upland, Tawau Hills Park, were 19.57 (SD: 8.36) and 7.10 (SD: 1.90) individuals per 100 km2, respectively, and the selectively logged, lowland Tabin Wildlife Reserve yielded an estimated density of 10.45 (SD: 3.38) individuals per 100 km2. The low detection frequencies recorded in our other survey sites and from published studies elsewhere in its range, and the absence of previous density estimates for this felid suggest that our density estimates may be from the higher end of their abundance spectrum. We provide recommendations for future marbled cat survey approaches. PMID:27007219

  10. Hunting, pet trade, and forest size effects on population viability of a critically endangered Neotropical primate, Sapajus xanthosternos (Wied-Neuwied, 1826).

    PubMed

    da Silva, Fabiana Araújo; Canale, Gustavo Rodrigues; Kierulff, Maria Cecília M; Duarte, Gabriela Teixeira; Paglia, Adriano Pereira; Bernardo, Christine S S

    2016-09-01

    The yellow-breasted capuchin monkey (Sapajus xanthosternos) is one of the seven Brazilian primates that are currently threatened with extinction. Although the species is known to be threatened by habitat loss, hunting, and illegal pet trade, few data exist on how these threats influence its long-term population persistence. We conducted population viability analyses (PVAs) to estimate minimum viable populations of S. xanthosternos under 10 threat scenarios (i.e., varying hunting pressure and varying number of infants captured for the pet trade) for five forest fragments with different estimated carrying capacities (K). We also estimated the minimum forest fragment size required to sustain viable populations living under the same 10 threat scenarios, based on critical numbers of K obtained in sensitivity tests, below which the population would be unviable. Our PVAs suggests that hunting has a higher impact on population viability in comparison to threats from the pet trade. Annual losses of adult and young females from hunting had the most detrimental effect on population persistence under all forest fragment sizes. Such hunting pressure is not sustainable for populations living in areas ≤3,460 ha, since these areas may not support populations of ≥84 individuals. The seven largest of the 13 protected areas currently harboring capuchins should be effective at maintaining viable populations in the long term even under the greatest threat scenarios we modeled. Other large forest patches, mainly in the western part of the species distribution, are recommended as priority areas for protection to increase the chances of capuchins' survival for the long term. In addition, forest fragments of ≤782.8 ha cannot maintain viable populations, even when there are no threats from hunting or from captures for the pet trade. Increased law enforcement is necessary to prevent the hunting and capture of capuchins, especially within larger forest fragments. Am. J. Primatol. 78

  11. Hunting, pet trade, and forest size effects on population viability of a critically endangered Neotropical primate, Sapajus xanthosternos (Wied-Neuwied, 1826).

    PubMed

    da Silva, Fabiana Araújo; Canale, Gustavo Rodrigues; Kierulff, Maria Cecília M; Duarte, Gabriela Teixeira; Paglia, Adriano Pereira; Bernardo, Christine S S

    2016-09-01

    The yellow-breasted capuchin monkey (Sapajus xanthosternos) is one of the seven Brazilian primates that are currently threatened with extinction. Although the species is known to be threatened by habitat loss, hunting, and illegal pet trade, few data exist on how these threats influence its long-term population persistence. We conducted population viability analyses (PVAs) to estimate minimum viable populations of S. xanthosternos under 10 threat scenarios (i.e., varying hunting pressure and varying number of infants captured for the pet trade) for five forest fragments with different estimated carrying capacities (K). We also estimated the minimum forest fragment size required to sustain viable populations living under the same 10 threat scenarios, based on critical numbers of K obtained in sensitivity tests, below which the population would be unviable. Our PVAs suggests that hunting has a higher impact on population viability in comparison to threats from the pet trade. Annual losses of adult and young females from hunting had the most detrimental effect on population persistence under all forest fragment sizes. Such hunting pressure is not sustainable for populations living in areas ≤3,460 ha, since these areas may not support populations of ≥84 individuals. The seven largest of the 13 protected areas currently harboring capuchins should be effective at maintaining viable populations in the long term even under the greatest threat scenarios we modeled. Other large forest patches, mainly in the western part of the species distribution, are recommended as priority areas for protection to increase the chances of capuchins' survival for the long term. In addition, forest fragments of ≤782.8 ha cannot maintain viable populations, even when there are no threats from hunting or from captures for the pet trade. Increased law enforcement is necessary to prevent the hunting and capture of capuchins, especially within larger forest fragments. Am. J. Primatol. 78

  12. Tertiary Origin and Pleistocene Diversification of Dragon Blood Tree (Dracaena cambodiana-Asparagaceae) Populations in the Asian Tropical Forests

    PubMed Central

    Dayanandan, Selvadurai; Nagaraju, Shivaprakash; Liu, Dong-Mei; Li, Qiao-Ming

    2013-01-01

    Background The origin of extraordinarily rich biodiversity in tropical forests is often attributed to evolution under stable climatic conditions over a long period or to climatic fluctuations during the recent Quaternary period. Here, we test these two hypotheses using Dracaena cambodiana, a plant species distributed in paleotropical forests. Methods We analyzed nucleotide sequence data of two chloroplast DNA (cpDNA: atpB-rbcL and trnD-trnT) regions and genotype data of six nuclear microsatellites from 15 populations (140 and 363 individuals, respectively) distributed in Indochina Peninsular and Hainan Island to infer the patterns of genetic diversity and phylogeographic structure. The population bottleneck and genetic drift were estimated based upon nuclear microsatellites data using the software programs BOTTLENECK and 2MOD. The lineage divergence times and past population dynamics based on cpDNA data were estimated using coalescent-based isolation-with-migration (IMa) and BEAST software programs. Results A significant phylogeographic structure (NST = 0.876, GST = 0.796, FST-SSR = 0.329, RST = 0.449; NST>GST, RST>FST-SSR, P<0.05) and genetic differentiation among populations were detected. Bottleneck analyses and Bayesian skyline plot suggested recent population reduction. The cpDNA haplotype network revealed the ancestral populations from the southern Indochina region expanded to northward. The most recent ancestor divergence time of D. cambodiana dated back to the Tertiary era and rapid diversification of terminal lineages corresponded to the Quaternary period. Conclusions The results indicated that the present distribution of genetic diversity in D. cambodiana was an outcome of Tertiary dispersal and rapid divergence during the Quaternary period under limited gene flow influenced by the uplift of Himalayan-Tibetan Plateau and Quaternary climatic fluctuations respectively. Evolutionary processes, such as extinction-recolonization during the

  13. Litter processing and population food intake of the mangrove crab Ucides cordatus in a high intertidal forest in northern Brazil

    NASA Astrophysics Data System (ADS)

    Nordhaus, Inga; Wolff, Matthias; Diele, Karen

    2006-03-01

    This study provides the first quantification of the population food intake of the litter-consuming mangrove crab Ucides cordatus (Ocypodidae, L. 1763) in a New World mangrove forest. Diet, feeding periodicity, gastric evacuation rates and size-dependent consumption were determined for this intensively exploited semi-terrestrial crab in different types of mangrove forest. Unlike many other crabs Ucides cordatus is a continuous feeder, as shown by gastrointestinal contents over a day's cycle. Starvation experiments revealed that most gastric evacuation occurs during the first 12 h after feeding, following an exponential decay function. Evacuation rates (0.35 h -1 and 0.31 h -1) for small (carapace width CW 2.5-3.5 cm) and large (CW 6.5-7.5 cm) crabs, respectively, and the mean daily gastrointestinal contents were used to calculate the daily food intake (DFI) of U. cordatus for both sexes and different size classes. DFI was strongly correlated to body size and ranged from 19.8 to 6.0% of body dry weight in small and large crabs, respectively. The daily energy intake of U. cordatus (37.6 kJ for a 65 g wet weight specimen) was high when compared to other leaf-eating crabs. Litter fall and propagule production were calculated as 16.38 t ha -1 y -1, corresponding to a daily mean of 4.49 g m -2 in a high intertidal Rhizophora mangle forest stand. The estimated population food intake of Ucides cordatus (4.1 g dw m -2 d -1) corresponds to 81.3% of this production. This high litter removal rate, a low litter quantity in burrows and high consumption rates during field experiments suggest that the local crab population is food-limited in many parts of the study area. The very efficient coupling of forest litter production and crab litter consumption is possible due to the high crab density and the low inundation frequency of the mangrove forests, allowing for prolonged foraging periods. By processing the major part of the litter, U. cordatus helps to retain nutrients and energy

  14. Population differentiation in tree-ring growth response of white fir (Abies concolor) to climate: Implications for predicting forest responses to climate change

    SciTech Connect

    Jensen, D.B.

    1993-10-01

    Forest succession models and correlative models have predicted 200--650 kilometer shifts in the geographic range of temperate forests and forest species as one response to global climate change. Few studies have investigated whether population differences may effect the response of forest species to climate change. This study examines differences in tree-ring growth, and in the phenotypic plasticity of tree-ring growth in 16-year old white fir, Abies concolor, from ten populations grown in four common gardens in the Sierra Nevada of California. For each population, tree-ring growth was modelled as a function of precipitation and degree-day sums. Tree-ring growth under three scenarios of doubled C0{sub 2} climates was estimated.

  15. Parameterization of the InVEST Crop Pollination Model to spatially predict abundance of wild blueberry (Vaccinium angustifolium Aiton) native bee pollinators in Maine, USA

    USGS Publications Warehouse

    Groff, Shannon C.; Loftin, Cynthia S.; Drummond, Frank; Bushmann, Sara; McGill, Brian J.

    2016-01-01

    Non-native honeybees historically have been managed for crop pollination, however, recent population declines draw attention to pollination services provided by native bees. We applied the InVEST Crop Pollination model, developed to predict native bee abundance from habitat resources, in Maine's wild blueberry crop landscape. We evaluated model performance with parameters informed by four approaches: 1) expert opinion; 2) sensitivity analysis; 3) sensitivity analysis informed model optimization; and, 4) simulated annealing (uninformed) model optimization. Uninformed optimization improved model performance by 29% compared to expert opinion-informed model, while sensitivity-analysis informed optimization improved model performance by 54%. This suggests that expert opinion may not result in the best parameter values for the InVEST model. The proportion of deciduous/mixed forest within 2000 m of a blueberry field also reliably predicted native bee abundance in blueberry fields, however, the InVEST model provides an efficient tool to estimate bee abundance beyond the field perimeter.

  16. Population maintenance of the short-lived shrub Sambucus in a deciduous forest.

    PubMed

    Abe, Shin; Motai, Hideyo; Tanaka, Hiroshi; Shibata, Mitsue; Kominami, Yohsuke; Nakashizuka, Tohru

    2008-04-01

    This study quantitatively clarifies the life history of a shrub, Sambucus racemosa ssp. sieboldiana, in an old-growth forest, the Ogawa Forest Reserve, Japan, by a demographic approach using a projection matrix model that incorporates interactions between demographic parameters and canopy height dynamics. S. racemosa is a common deciduous shrub in central Japan and is known to grow predominantly at forest edges or roadsides. This indicates that it is a highly light-demanding species, and occurrence in gaps in old-growth stands suggests its "fugitive," gap-dependent life history in old-growth forests. We found that one distinctive feature of this species was that its seedlings can survive well in shaded conditions by alternating stems every year like perennial herb species. Matrix model analyses demonstrated that S. racemosa can continuously regenerate under the present disturbance regime of this forest and is highly adaptable to the structural dynamics of the old-growth forest. The maturity of S. racemosa shrubs depends on their size, and nearly all (>90%) of the mature (reproducing) individuals were found in gaps or near gaps. But wide seed dispersal by birds and the ability to form both seed banks and seedling banks, the latter of which has been regarded as a common characteristic of shade-tolerant climax species, probably increase the species' chances to encounter canopy gaps. Dynamic-canopied matrix models showed that the greatest elasticity is with shaded seedling survival. The frequent stem alternation of shaded seedlings often makes the growth rate negative, but the survival rate of seedlings in low light awaiting new gap creation is remarkably high (0.93 yr(-1)). The lower survival rate of the larger individuals and smaller minimum size to start reproduction than other canopy or subcanopy shade-tolerant species indicate that S. racemosa has the potential to reproduce before the closure of the encountered gaps and to complete its life history rapidly.

  17. A Mathematical Model for the Bee Hive of Apis Mellifera

    NASA Astrophysics Data System (ADS)

    Antonioni, Alberto; Bellom, Fabio Enrici; Montabone, Andrea; Venturino, Ezio

    2010-09-01

    In this work we introduce and discuss a model for the bee hive, in which only adult bees and drones are modeled. The role that the latter have in the system is interesting, their population can retrieve even if they are totally absent from the bee hive. The feasibility and stability of the equilibria is studied numerically. A simplified version of the model shows the importance of the drones' role, in spite of the fact that it allows only a trivial equilibrium. For this simplified system, no Hopf bifurcations are shown to arise.

  18. Surveys of Puerto Rican screech-owl populations in large-tract and fragmented forest habitats

    USGS Publications Warehouse

    Pardieck, K.L.; Meyers, J.M.; Pagan, M.

    1996-01-01

    We conducted road surveys of Puerto Rican Screech-Owls (Otus nudipes) by playing conspecific vocalizations in secondary wet forest and fragmented secondary moist forest in rural areas of eastern Puerto Rico. Six paired surveys were conducted bi-weekly beginning in April. We recorded number of owl responses, cloud cover, wind speed, moon phase, and number of passing cars during 5-min stops at 60 locations. Owls responded in similar numbers (P > 0.05) in both habitat types. Also, we detected no association with cloud cover, wind speed, moon phase, or passing cars.

  19. High population density of black-handed spider monkeys (Ateles geoffroyi) in Costa Rican lowland wet forest.

    PubMed

    Weghorst, Jennifer A

    2007-04-01

    The main objective of this study was to estimate the population density and demographic structure of spider monkeys living in wet forest in the vicinity of Sirena Biological Station, Corcovado National Park, Costa Rica. Results of a 14-month line-transect survey showed that spider monkeys of Sirena have one of the highest population densities ever recorded for this genus. Density estimates varied, however, depending on the method chosen to estimate transect width. Data from behavioral monitoring were available to compare density estimates derived from the survey, providing a check of the survey's accuracy. A combination of factors has most probably contributed to the high density of Ateles, including habitat protection within a national park and high diversity of trees of the fig family, Moraceae. Although natural densities of spider monkeys at Sirena are substantially higher than those recorded at most other sites and in previous studies at this site, mean subgroup size and age ratios were similar to those determined in previous studies. Sex ratios were similar to those of other sites with high productivity. Although high densities of preferred fruit trees in the wet, productive forests of Sirena may support a dense population of spider monkeys, other demographic traits recorded at Sirena fall well within the range of values recorded elsewhere for the species.

  20. High population density of black-handed spider monkeys (Ateles geoffroyi) in Costa Rican lowland wet forest.

    PubMed

    Weghorst, Jennifer A

    2007-04-01

    The main objective of this study was to estimate the population density and demographic structure of spider monkeys living in wet forest in the vicinity of Sirena Biological Station, Corcovado National Park, Costa Rica. Results of a 14-month line-transect survey showed that spider monkeys of Sirena have one of the highest population densities ever recorded for this genus. Density estimates varied, however, depending on the method chosen to estimate transect width. Data from behavioral monitoring were available to compare density estimates derived from the survey, providing a check of the survey's accuracy. A combination of factors has most probably contributed to the high density of Ateles, including habitat protection within a national park and high diversity of trees of the fig family, Moraceae. Although natural densities of spider monkeys at Sirena are substantially higher than those recorded at most other sites and in previous studies at this site, mean subgroup size and age ratios were similar to those determined in previous studies. Sex ratios were similar to those of other sites with high productivity. Although high densities of preferred fruit trees in the wet, productive forests of Sirena may support a dense population of spider monkeys, other demographic traits recorded at Sirena fall well within the range of values recorded elsewhere for the species. PMID:17265010

  1. Using mechanistic models to understand synchrony in forest insect populations: the North American gypsy moth as a case study.

    PubMed

    Abbott, Karen C; Dwyer, Greg

    2008-11-01

    In many forest insects, subpopulations fluctuate concurrently across large geographical areas, a phenomenon known as population synchrony. Because of the large spatial scales involved, empirical tests to identify the causes of synchrony are often impractical. Simple models are, therefore, a useful aid to understanding, but data often seem to contradict model predictions. For instance, chaotic population dynamics and limited dispersal are not uncommon among synchronous forest defoliators, yet both make it difficult to achieve synchrony in simple models. To test whether this discrepancy can be explained by more realistic models, we introduced dispersal and spatially correlated stochasticity into a mechanistic population model for the North American gypsy moth Lymantria dispar. The resulting model shows both chaotic dynamics and spatial synchrony, suggesting that chaos and synchrony can be reconciled by the incorporation of realistic dynamics and spatial structure. By relating alterations in model structure to changes in synchrony levels, we show that the synchrony is due to a combination of spatial covariance in environmental stochasticity and the origins of chaos in our multispecies model.

  2. Low genetic diversity and high differentiation among relict populations of the neotropical gymnosperm Podocarpus sellowii (Klotz.) in the Atlantic Forest.

    PubMed

    Dantas, Liliane G; Esposito, Tiago; de Sousa, Adna Cristina Barbosa; Félix, Leonardo; Amorim, Lidiane L B; Benko-Iseppon, Ana Maria; Batalha-Filho, Henrique; Pedrosa-Harand, Andrea

    2015-02-01

    Podocarpus sellowii (Podocarpaceae) is one of only a few gymnosperms native to Brazil and the sole species of the genus found in the northeastern region of that country. It has a very restricted distribution in this region, with only three known populations in highland forests (called Brejos de Altitude), which apparently have been isolated from each other since the Pleistocene. Due to this long-term isolation and the fact that these populations have few adult individuals and suffer great anthropogenic pressure, low genetic variability is expected, compromising their long-term viability. The present work assessed the genetic variability and structure of northeastern populations of P. sellowii to investigate the role of Pleistocene glaciations on the genetic relationships between them and to propose strategies for their conservation by analyzing the SSR and ISSR markers of adult and juvenile individuals. Low genetic diversity was found with both markers, associated with a high differentiation of the Brejo de Baturité population in relation to the others-suggesting their isolation at different points in time, probably during the Pleistocene. Actions directed towards increasing the genetic diversity of these populations will be needed, such as planting seedlings with high genetic variability-but the high degrees of differentiation observed between the populations must be taken into account.

  3. Dynamics of Litter Decomposition, Microbiota Populations, and Nutrient Movement Following Nitrogen and Phosphorus Additions to a Deciduous Forest Stand

    SciTech Connect

    Kelly, J.M.

    2002-10-29

    The objective of this study was quantification of the dynamics of litter decomposition, microbiota populations, and nutrient movement in response to nitrogen and phosphorus additions to a deciduous forest stand. Nitrogen (urea) was applied at rates of 0, 550, and 1100 kg/ha in combination with phosphorus (concentrated superphosphate) at rates of 0, 275, and 550 kg/ha. Total loss of organic material from white oak, red maple, and black gum litter bags over a 16-month period was 34, 35, and 45%, respectively. Phosphorus treatment retarded weight loss from litter bags of all species. Weight loss for the 0-, 275-, and 55-kg/ha levels of phosphorus averaged 23, 20, and 19% for white oak; 26, 25, and 25% for red maple; 29, 27 and 26% for black gum. Weight losses were increased by a small amount (1 to 2%) or not at all by nitrogen treatment. The NP interfaction weight loss means were intermediate to the main treatment means. The increase in decomposition associated with nitrogen was offset by the decrease associated with phosphorus. Litter and soil bacterial populations were significantly increased by nitrogen additions, while litter and soil fungi did not respond to nitrogen. Soil fungal populations were increased by phosphorus addition, while litter bacterial populations were reduced. Litter fungi and soil bacteria did not respond to phosphorus. Combined additions of nitrogen and phosphorus increased bacterial populations, though not as much as nitrogen alone. There was a good correlation (r = 0.70) between bacterial population and litter weight loss.

  4. Spatial and temporal analysis of populations of the Sudden Oak Death pathogen in Oregon forests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sudden oak death caused by the oomycete Phytophthora ramorum was first discovered in California towards the end of the 20th century and subsequently emerged on tanoak forests in Oregon before its first detection in 2001 by aerial surveys. The Oregon Department of Forestry has since monitored the epi...

  5. Analysis of the contribution of forest pathways to the radiation exposure of different population groups in the Bryansk region of Russia.

    PubMed

    Fesenko, S V; Voigt, G; Spiridonov, S I; Sanzharova, N I; Gontarenko, I A; Belli, M; Sansone, U

    2000-12-01

    The experience gained in the aftermath of serious radiation accidents shows that forests are an important source of external and internal exposure of the affected population. This paper presents the results of an assessment of the major radiological consequences for forests of Russia, most heavily contaminated after the Chernobyl nuclear power plant (ChNPP) accident. Illustrated in the Novozybkovsky district of the Russian Federation, the significance of different forest exposure pathways is estimated and the doses resulting from forest pathways are compared with the doses from agricultural products. It has been found that the contribution of mushrooms and berries to the internal doses of the population, relative to the doses from agricultural products, varied from 10-15% in 1987 to 40-45% in 1996. The results indicate large differences in internal exposure of members of the "critical groups" and "normal population", increasing with time after deposition. Data are presented that give information on the contribution of forests to the collective doses of inhabitants of the area under consideration. It has been shown that for 10 years after the accident (1987-1996), the contribution of forest products to the collective dose of the rural population living in contaminated forests of the Novozybkovsky district, amounts to about 20% (213 person Sv) of the total collective dose of internal and external exposures. However, a potential impact of these products including the dose from exported products is much higher and might reach 659 person Sv. It has been found that in the long-term after the ChNPP accident, serious attention should be given to forest countermeasures, and restoration strategies should be selected on the basis of a combined analysis of the effectiveness of forest and agricultural countermeasures. PMID:11200973

  6. Magnetic effect on dancing bees

    NASA Technical Reports Server (NTRS)

    Lindauer, M.; Martin, H.

    1972-01-01

    Bee sensitivity to the earth's magnetic field is studied. Data cover sensitivity range and the use of magnetoreception for orientation purposes. Experimental results indicate bee orientation is aided by gravity fields when the magnetic field is compensated.

  7. Annual dynamics of wild bee densities: attractiveness and productivity effects of oilseed rape.

    PubMed

    Riedinger, Verena; Mitesser, Oliver; Hovestadt, Thomas; Steffan-Dewenter, Ingolf; Holzschuh, Andrea

    2015-05-01

    Mass-flowering crops may affect long-term population dynamics, but effects on pollinators have never been studied across several years. We monitored wild bees in oilseed rape fields in 16 landscapes in Germany in two consecutive years. Effects on bee densities of landscape oilseed rape cover in the years of monitoring and in the previous years were evaluated with landscape data from three consecutive years. We fit empirical data to a mechanistic model to provide estimates for oilseed rape attractiveness and its effect on bee productivity in comparison to the rest of the landscape, and we evaluated consequences for pollinator densities in consecutive years. Our results show that high oilseed rape cover in the previous year enhances current densities of wild bees (except for bumble bees). Moreover, we show a strong attractiveness of and dilution on (i.e., decreasing bee densities with increasing landscape oilseed rape cover) oilseed rape for bees during flowering in the current year, modifying the effect of the previous year's oilseed rape cover in the case of wild bees (excluding Bombus). As long as other factors such as nesting sites or natural enemies do not limit bee reproduction, our findings suggest long-term positive effects of mass-flowering crops on bee populations, at least for non-Bombus generalists, which possibly help to maintain crop pollination services even when crop area increases. Similar effects are conceivable for other organisms providing ecosystem services in annual crops and should be considered in future studies. PMID:26236848

  8. Annual dynamics of wild bee densities: attractiveness and productivity effects of oilseed rape.

    PubMed

    Riedinger, Verena; Mitesser, Oliver; Hovestadt, Thomas; Steffan-Dewenter, Ingolf; Holzschuh, Andrea

    2015-05-01

    Mass-flowering crops may affect long-term population dynamics, but effects on pollinators have never been studied across several years. We monitored wild bees in oilseed rape fields in 16 landscapes in Germany in two consecutive years. Effects on bee densities of landscape oilseed rape cover in the years of monitoring and in the previous years were evaluated with landscape data from three consecutive years. We fit empirical data to a mechanistic model to provide estimates for oilseed rape attractiveness and its effect on bee productivity in comparison to the rest of the landscape, and we evaluated consequences for pollinator densities in consecutive years. Our results show that high oilseed rape cover in the previous year enhances current densities of wild bees (except for bumble bees). Moreover, we show a strong attractiveness of and dilution on (i.e., decreasing bee densities with increasing landscape oilseed rape cover) oilseed rape for bees during flowering in the current year, modifying the effect of the previous year's oilseed rape cover in the case of wild bees (excluding Bombus). As long as other factors such as nesting sites or natural enemies do not limit bee reproduction, our findings suggest long-term positive effects of mass-flowering crops on bee populations, at least for non-Bombus generalists, which possibly help to maintain crop pollination services even when crop area increases. Similar effects are conceivable for other organisms providing ecosystem services in annual crops and should be considered in future studies.

  9. Time series analysis of fine particulate matter and asthma reliever dispensations in populations affected by forest fires

    PubMed Central

    2013-01-01

    Background Several studies have evaluated the association between forest fire smoke and acute exacerbations of respiratory diseases, but few have examined effects on pharmaceutical dispensations. We examine the associations between daily fine particulate matter (PM2.5) and pharmaceutical dispensations for salbutamol in forest fire-affected and non-fire-affected populations in British Columbia (BC), Canada. Methods We estimated PM2.5 exposure for populations in administrative health areas using measurements from central monitors. Remote sensing data on fires were used to classify the populations as fire-affected or non-fire-affected, and to identify extreme fire days. Daily counts of salbutamol dispensations between 2003 and 2010 were extracted from the BC PharmaNet database. We estimated rate ratios (RR) and 95% confidence intervals (CIs) for each population during all fire seasons and on extreme fire days, adjusted for temperature, humidity, and temporal trends. Overall effects for fire-affected and non-fire-affected populations were estimated via meta-regression. Results Fire season PM2.5 was positively associated with salbutamol dispensations in all fire-affected populations, with a meta-regression RR (95% CI) of 1.06 (1.04-1.07) for a 10 ug/m3 increase. Fire season PM2.5 was not significantly associated with salbutamol dispensations in non-fire-affected populations, with a meta-regression RR of 1.00 (0.98-1.01). On extreme fire days PM2.5 was positively associated with salbutamol dispensations in both population types, with a global meta-regression RR of 1.07 (1.04 - 1.09). Conclusions Salbutamol dispensations were clearly associated with fire-related PM2.5. Significant associations were observed in smaller populations (range: 8,000 to 170,000 persons, median: 26,000) than those reported previously, suggesting that salbutamol dispensations may be a valuable outcome for public health surveillance during fire events. PMID:23356966

  10. Characterizing the Impact of Commercial Pollen Substitute Diets on the Level of Nosema spp. in Honey Bees (Apis mellifera L.).

    PubMed

    Fleming, James C; Schmehl, Daniel R; Ellis, James D

    2015-01-01

    Western honey bee (Apis mellifera L.) populations face declines commonly attributed to pesticide, pathogen, and parasite stress. One way beekeepers combat these stressors is by providing supplemental protein diets to honey bee colonies to ensure adequate colony nutrition. However Nosema spp., a microsporidian parasite of the honey bee, is thought to be associated closely with a colony's nutritional intake, thus possibly negating any benefit the bees otherwise would have received from a nutritional supplement. Through three objectives, we examined how adult bees' consumption of wildflower pollen or commercial pollen substitute diets affected Nosema levels in the bees' midguts. For our first objective, we investigated how method of inoculation with Nosema affects infection levels in inoculated bees. Bees were infected with spores of Nosema four days after emergence. On day 15, bees were collected from the cages and Nosema spores were quantified. We found that inoculation through the pollen diet resulted in the highest Nosema levels in inoculated bees. In our second and third objectives, we provided the test diets to caged, newly emerged bees for a period of 15 days. Bees consuming pollen and a sucrose solution had more Nosema in their midguts than did bees consuming the sucrose solution alone (control). The overall volume of diet consumed by the bees did not correlate with the level of Nosema in their midguts. The level of Nosema was higher in bees fed certain commercial pollen substitute diets than in bees fed wildflower pollen. Our study illustrates how providing nutritional supplements to adult honey bees can impact the intensity of Nosema in their midguts. PMID:26226229

  11. Characterizing the Impact of Commercial Pollen Substitute Diets on the Level of Nosema spp. in Honey Bees (Apis mellifera L.).

    PubMed

    Fleming, James C; Schmehl, Daniel R; Ellis, James D

    2015-01-01

    Western honey bee (Apis mellifera L.) populations face declines commonly attributed to pesticide, pathogen, and parasite stress. One way beekeepers combat these stressors is by providing supplemental protein diets to honey bee colonies to ensure adequate colony nutrition. However Nosema spp., a microsporidian parasite of the honey bee, is thought to be associated closely with a colony's nutritional intake, thus possibly negating any benefit the bees otherwise would have received from a nutritional supplement. Through three objectives, we examined how adult bees' consumption of wildflower pollen or commercial pollen substitute diets affected Nosema levels in the bees' midguts. For our first objective, we investigated how method of inoculation with Nosema affects infection levels in inoculated bees. Bees were infected with spores of Nosema four days after emergence. On day 15, bees were collected from the cages and Nosema spores were quantified. We found that inoculation through the pollen diet resulted in the highest Nosema levels in inoculated bees. In our second and third objectives, we provided the test diets to caged, newly emerged bees for a period of 15 days. Bees consuming pollen and a sucrose solution had more Nosema in their midguts than did bees consuming the sucrose solution alone (control). The overall volume of diet consumed by the bees did not correlate with the level of Nosema in their midguts. The level of Nosema was higher in bees fed certain commercial pollen substitute diets than in bees fed wildflower pollen. Our study illustrates how providing nutritional supplements to adult honey bees can impact the intensity of Nosema in their midguts.

  12. Conservation Value and Permeability of Neotropical Oil Palm Landscapes for Orchid Bees

    PubMed Central

    Livingston, George; Jha, Shalene; Vega, Andres; Gilbert, Lawrence

    2013-01-01

    The proliferation of oil palm plantations has led to dramatic changes in tropical landscapes across the globe. However, relatively little is known about the effects of oil palm expansion on biodiversity, especially in key ecosystem-service providing organisms like pollinators. Rapid land use change is exacerbated by limited knowledge of the mechanisms causing biodiversity decline in the tropics, particularly those involving landscape features. We examined these mechanisms by undertaking a survey of orchid bees, a well-known group of Neotropical pollinators, across forest and oil palm plantations in Costa Rica. We used chemical baits to survey the community in four regions: continuous forest sites, oil palm sites immediately adjacent to forest, oil palm sites 2km from forest, and oil palm sites greater than 5km from forest. We found that although orchid bees are present in all environments, orchid bee communities diverged across the gradient, and community richness, abundance, and similarity to forest declined as distance from forest increased. In addition, mean phylogenetic distance of the orchid bee community declined and was more clustered in oil palm. Community traits also differed with individuals in oil palm having shorter average tongue length and larger average geographic range size than those in the forest. Our results indicate two key features about Neotropical landscapes that contain oil palm: 1) oil palm is selectively permeable to orchid bees and 2) orchid bee communities in oil palm have distinct phylogenetic and trait structure compared to communities in forest. These results suggest that conservation and management efforts in oil palm-cultivating regions should focus on landscape features. PMID:24147137

  13. Wild Trypanosoma cruzi I genetic diversity in Brazil suggests admixture and disturbance in parasite populations from the Atlantic Forest region

    PubMed Central

    2014-01-01

    Background Trypanosoma cruzi (Kinetoplastida, Trypanosomatidae) infection is an ancient and widespread zoonosis distributed throughout the Americas. Ecologically, Brazil comprises several distinct biomes: Amazonia, Cerrado, Caatinga, Pantanal and the Atlantic Forest. Sylvatic T. cruzi transmission is known to occur throughout these biomes, with multiple hosts and vectors involved. Parasite species-level genetic diversity can be a useful marker for ecosystem health. Our aims were to: investigate sylvatic T. cruzi genetic diversity across different biomes, detect instances of genetic exchange, and explore the possible impact of ecological disturbance on parasite diversity at an intra-species level. Methods We characterised 107 isolates of T. cruzi I (TcI; discrete typing unit, DTU I) from different major Brazilian biomes with twenty-seven nuclear microsatellite loci. A representative subset of biologically cloned isolates was further characterised using ten mitochondrial gene loci. We compared these data generated from Brazilian TcI isolates from around America. Results Genetic diversity was remarkably high, including one divergent cluster that branched outside the known genetic diversity of TcI in the Americas. We detected evidence for mitochondrial introgression and genetic exchange between the eastern Amazon and Caatinga. Finally, we found strong signatures of admixture among isolates from the Atlantic Forest region by comparison to parasites from other study sites. Conclusions Atlantic Forest sylvatic TcI populations are highly fragmented and admixed by comparison to others around Brazil. We speculate on: the possible causes of Atlantic Forest admixture; the role of T. cruzi as a sentinel for ecosystem health, and the impact disrupted sylvatic transmission cycles might have on accurate source attribution in oral outbreaks. PMID:24903849

  14. Influence of thinning of Douglas-fir forests on population parameters and diet of northern flying squirrels

    USGS Publications Warehouse

    Gomez, D.M.; Anthony, R.G.; Hayes, J.P.

    2005-01-01

    We investigated the effects of thinning young (35- to 45-yr-old) Douglas-fir (Pseudotsuga menziesii) forests on density, survival, body mass, movements, and diets of northern flying squirrels (Glaucomys sabrinus) in the northern coast range of Oregon. We used a repeated measures, randomized block design with 3 treatments (control, moderate thinning, and heavy thinning) and 4 replicates to study diets and population characteristics from 1994-1997. Densities of flying squirrels were variable in space and time, but they were positively correlated to biomass and frequency of fungal sporocarps, suggesting they were responding to food resources rather than forest structure. Fungal sporocarps comprised a major portion of the squirrel's diet, and other vegetative material made up the remainder of the diet. Several fungal genera including Gautieria, Geopora, Hymenogaster, Hysterangium, Melanogaster, and Rhizopogon were found more frequently in diets than on the trapping grids and therefore appeared to be selected by the squirrels. Flying squirrel movements were negatively correlated with the frequency of occurrence of fungal sporocarps at trap stations, suggesting that squirrels traveled greater distances to find fungal sporocarps where these food items were more sparsely distributed. We hypothesized that flying squirrel densities would be relatively low in these young, structurally simple forests; however, densities on some of the grids were >1.5 squirrels/ha, which was comparable to densities described for the species in late-successional forests. Our results indicated that commercial thinning did not have measurable short-term effects on density, survival, or body mass of flying squirrels.

  15. Bee Line BR-1 Racer

    NASA Technical Reports Server (NTRS)

    1926-01-01

    Bee Line BR-1 Racer: The Bee Line BR-1 was a racing aircraft used to compete in the 1922 Pulitzer Air Race. The aircraft and its sister ship, the Bee Line BR-2, came to Langley and the NACA in 1926. The BR-1 is shown in the NACA hangar at Langley Field in early 1926.

  16. Absence of Leishmaniinae and Nosematidae in stingless bees

    PubMed Central

    Nunes-Silva, Patrícia; Piot, Niels; Meeus, Ivan; Blochtein, Betina; Smagghe, Guy

    2016-01-01

    Bee pollination is an indispensable component of global food production and plays a crucial role in sustainable agriculture. The worldwide decline of bee populations, including wild pollinators, poses a threat to this system. However, most studies to date are situated in temperate regions where Apini and Bombini are very abundant pollinators. Tropical and subtropical regions where stingless bees (Apidae: Meliponini) are generally very common, are often overlooked. These bees also face pressure due to deforestation and agricultural intensification as well as the growing use and spread of exotic pollinators as Apis mellifera and Bombus species. The loss or decline of this important bee tribe would have a large impact on their provided ecosystem services, in both wild and agricultural landscapes. The importance of pollinator diseases, which can contribute to decline, has not been investigated so far in this bee tribe. Here we report on the first large pathogen screening of Meliponini species in southern Brazil. Remarkably we observed that there was an absence of Leishmaniinae and Nosematidae, and a very low occurrence of Apicystis bombi. Our data on disease prevalence in both understudied areas and species, can greatly improve our knowledge on the distribution of pathogens among bee species. PMID:27586080

  17. Absence of Leishmaniinae and Nosematidae in stingless bees.

    PubMed

    Nunes-Silva, Patrícia; Piot, Niels; Meeus, Ivan; Blochtein, Betina; Smagghe, Guy

    2016-01-01

    Bee pollination is an indispensable component of global food production and plays a crucial role in sustainable agriculture. The worldwide decline of bee populations, including wild pollinators, poses a threat to this system. However, most studies to date are situated in temperate regions where Apini and Bombini are very abundant pollinators. Tropical and subtropical regions where stingless bees (Apidae: Meliponini) are generally very common, are often overlooked. These bees also face pressure due to deforestation and agricultural intensification as well as the growing use and spread of exotic pollinators as Apis mellifera and Bombus species. The loss or decline of this important bee tribe would have a large impact on their provided ecosystem services, in both wild and agricultural landscapes. The importance of pollinator diseases, which can contribute to decline, has not been investigated so far in this bee tribe. Here we report on the first large pathogen screening of Meliponini species in southern Brazil. Remarkably we observed that there was an absence of Leishmaniinae and Nosematidae, and a very low occurrence of Apicystis bombi. Our data on disease prevalence in both understudied areas and species, can greatly improve our knowledge on the distribution of pathogens among bee species. PMID:27586080

  18. Absence of Leishmaniinae and Nosematidae in stingless bees.

    PubMed

    Nunes-Silva, Patrícia; Piot, Niels; Meeus, Ivan; Blochtein, Betina; Smagghe, Guy

    2016-09-02

    Bee pollination is an indispensable component of global food production and plays a crucial role in sustainable agriculture. The worldwide decline of bee populations, including wild pollinators, poses a threat to this system. However, most studies to date are situated in temperate regions where Apini and Bombini are very abundant pollinators. Tropical and subtropical regions where stingless bees (Apidae: Meliponini) are generally very common, are often overlooked. These bees also face pressure due to deforestation and agricultural intensification as well as the growing use and spread of exotic pollinators as Apis mellifera and Bombus species. The loss or decline of this important bee tribe would have a large impact on their provided ecosystem services, in both wild and agricultural landscapes. The importance of pollinator diseases, which can contribute to decline, has not been investigated so far in this bee tribe. Here we report on the first large pathogen screening of Meliponini species in southern Brazil. Remarkably we observed that there was an absence of Leishmaniinae and Nosematidae, and a very low occurrence of Apicystis bombi. Our data on disease prevalence in both understudied areas and species, can greatly improve our knowledge on the distribution of pathogens among bee species.

  19. [Spatial autocorrelation of genetic structure of Prunus padus population in broadleaved Korean pine forest of Changbai Mountains].

    PubMed

    Niu, Xiao-Min; Shi, Shuai; Wang, Zheng-Feng; Ye, Wan-Hui; Hao, Zhan-Qing

    2014-02-01

    All 396 Prunus padus individuals of the population with DBH (diameter at breast height) > or = 1 cm were sampled in a 25 hm2 broadleaved Korean pine forest plot of Changbai Mountains and divided into three DBH classes: 1-3 cm, 3-10 cm, and >10 cm. They were then genotyped using microsatellite loci. The spatial autocorrelation of their genetic structure was analyzed at different distance classes and life stages. The results showed that positive autocorrelation mainly occurred at scales less than 70 m, while negative autocorrelation occurred at scales larger than 110 m. The spatial genetic structure (SGS) at different life stages was similar due to limited pollen/seed dispersal and asexual reproduction. No significant self-thinning occurred in the studied population. PMID:24830226

  20. Mating system, population growth, and management scenario for Kalanchoe pinnata in an invaded seasonally dry tropical forest.

    PubMed

    González de León, Salvador; Herrera, Ileana; Guevara, Roger

    2016-07-01

    Ecological invasions are a major issue worldwide, where successful invasion depends on traits that facilitate dispersion, establishment, and population growth. The nonnative succulent plant Kalanchoe pinnata, reported as invasive in some countries, is widespread in remnants of seasonally dry tropical forest on a volcanic outcrop with high conservation value in east-central Mexico where we assessed its mating system and demographic growth and identified management strategies. To understand its local mating system, we conducted hand-pollination treatments, germination, and survival experiments. Based on the experimental data, we constructed a life-stage population matrix, identified the key traits for population growth, weighted the contributions of vegetative and sexual reproduction, and evaluated management scenarios. Hand-pollination treatments had slight effects on fruit and seed setting, as well as on germination. With natural pollination treatment, the successful germination of seeds from only 2/39 fruit suggests occasional effective natural cross-pollination. The ratios of the metrics for self- and cross-pollinated flowers suggest that K. pinnata is partially self-compatible. Most of the pollinated flowers developed into fruit, but the seed germination and seedling survival rates were low. Thus, vegetative propagation and juvenile survival are the main drivers of population growth. Simulations of a virtual K. pinnata population suggest that an intense and sustained weeding campaign will reduce the population within at least 10 years. Synthesis and applications. The study population is partially self-compatible, but sexual reproduction by K. pinnata is limited at the study site, and population growth is supported by vegetative propagation and juvenile survival. Demographic modeling provides key insights and realistic forecasts on invasion process and therefore is useful to design management strategies. PMID:27386095

  1. Mating system, population growth, and management scenario for Kalanchoe pinnata in an invaded seasonally dry tropical forest.

    PubMed

    González de León, Salvador; Herrera, Ileana; Guevara, Roger

    2016-07-01

    Ecological invasions are a major issue worldwide, where successful invasion depends on traits that facilitate dispersion, establishment, and population growth. The nonnative succulent plant Kalanchoe pinnata, reported as invasive in some countries, is widespread in remnants of seasonally dry tropical forest on a volcanic outcrop with high conservation value in east-central Mexico where we assessed its mating system and demographic growth and identified management strategies. To understand its local mating system, we conducted hand-pollination treatments, germination, and survival experiments. Based on the experimental data, we constructed a life-stage population matrix, identified the key traits for population growth, weighted the contributions of vegetative and sexual reproduction, and evaluated management scenarios. Hand-pollination treatments had slight effects on fruit and seed setting, as well as on germination. With natural pollination treatment, the successful germination of seeds from only 2/39 fruit suggests occasional effective natural cross-pollination. The ratios of the metrics for self- and cross-pollinated flowers suggest that K. pinnata is partially self-compatible. Most of the pollinated flowers developed into fruit, but the seed germination and seedling survival rates were low. Thus, vegetative propagation and juvenile survival are the main drivers of population growth. Simulations of a virtual K. pinnata population suggest that an intense and sustained weeding campaign will reduce the population within at least 10 years. Synthesis and applications. The study population is partially self-compatible, but sexual reproduction by K. pinnata is limited at the study site, and population growth is supported by vegetative propagation and juvenile survival. Demographic modeling provides key insights and realistic forecasts on invasion process and therefore is useful to design management strategies.

  2. Very low mitochondrial variability in a stingless bee endemic to cerrado

    PubMed Central

    Brito, Rute Magalhães; de Oliveira Francisco, Flávio; Françoso, Elaine; Santiago, Leandro Rodrigues; Arias, Maria Cristina

    2013-01-01

    Partamona mulata is a stingless bee species endemic to cerrado, a severely threatened phytogeographical domain. Clearing for pasture without proper soil treatment in the cerrado facilitates the proliferation of termite ground nests, which are the nesting sites for P. mulata. The genetic consequences of these changes in the cerrado environment for bee populations are still understudied. In this work, we analyzed the genetic diversity of 48 colonies of P. mulata collected throughout the species’ distribution range by sequencing two mitochondrial genes, cytochrome oxidase I and cytochrome B. A very low polymorphism rate was observed when compared to another Partamona species from the Atlantic forest. Exclusive haplotypes were observed in two of the five areas sampled. The sharing of two haplotypes between collection sites separated by a distance greater than the flight range of queens indicates an ancient distribution for these haplotypes. The low haplotype and nucleotide diversity observed here suggests that P. mulata is either a young species or one that has been through population bottlenecks. Locally predominant and exclusive haplotypes (H2 and H4) may have been derived from local remnants through cerrado deforestation and the expansion of a few colonies with abundant nesting sites. PMID:23569418

  3. Climate-Based Models for Pulsed Resources Improve Predictability of Consumer Population Dynamics: Outbreaks of House Mice in Forest Ecosystems

    PubMed Central

    Holland, E. Penelope; James, Alex; Ruscoe, Wendy A.; Pech, Roger P.; Byrom, Andrea E.

    2015-01-01

    Accurate predictions of the timing and magnitude of consumer responses to episodic seeding events (masts) are important for understanding ecosystem dynamics and for managing outbreaks of invasive species generated by masts. While models relating consumer populations to resource fluctuations have been developed successfully for a range of natural and modified ecosystems, a critical gap that needs addressing is better prediction of resource pulses. A recent model used change in summer temperature from one year to the next (ΔT) for predicting masts for forest and grassland plants in New Zealand. We extend this climate-based method in the framework of a model for consumer–resource dynamics to predict invasive house mouse (Mus musculus) outbreaks in forest ecosystems. Compared with previous mast models based on absolute temperature, the ΔT method for predicting masts resulted in an improved model for mouse population dynamics. There was also a threshold effect of ΔT on the likelihood of an outbreak occurring. The improved climate-based method for predicting resource pulses and consumer responses provides a straightforward rule of thumb for determining, with one year’s advance warning, whether management intervention might be required in invaded ecosystems. The approach could be applied to consumer–resource systems worldwide where climatic variables are used to model the size and duration of resource pulses, and may have particular relevance for ecosystems where global change scenarios predict increased variability in climatic events. PMID:25785866

  4. Climate-based models for pulsed resources improve predictability of consumer population dynamics: outbreaks of house mice in forest ecosystems.

    PubMed

    Holland, E Penelope; James, Alex; Ruscoe, Wendy A; Pech, Roger P; Byrom, Andrea E

    2015-01-01

    Accurate predictions of the timing and magnitude of consumer responses to episodic seeding events (masts) are important for understanding ecosystem dynamics and for managing outbreaks of invasive species generated by masts. While models relating consumer populations to resource fluctuations have been developed successfully for a range of natural and modified ecosystems, a critical gap that needs addressing is better prediction of resource pulses. A recent model used change in summer temperature from one year to the next (ΔT) for predicting masts for forest and grassland plants in New Zealand. We extend this climate-based method in the framework of a model for consumer-resource dynamics to predict invasive house mouse (Mus musculus) outbreaks in forest ecosystems. Compared with previous mast models based on absolute temperature, the ΔT method for predicting masts resulted in an improved model for mouse population dynamics. There was also a threshold effect of ΔT on the likelihood of an outbreak occurring. The improved climate-based method for predicting resource pulses and consumer responses provides a straightforward rule of thumb for determining, with one year's advance warning, whether management intervention might be required in invaded ecosystems. The approach could be applied to consumer-resource systems worldwide where climatic variables are used to model the size and duration of resource pulses, and may have particular relevance for ecosystems where global change scenarios predict increased variability in climatic events.

  5. Bamboo thickets alter the demographic structure of Euterpe edulis population: A keystone, threatened palm species of the Atlantic forest

    NASA Astrophysics Data System (ADS)

    Rother, Débora Cristina; Rodrigues, Ricardo Ribeiro; Pizo, Marco Aurélio

    2016-01-01

    The rapid spread of bamboos can strongly affect forest structure by interfering plant regeneration and reducing local biodiversity. Considering that bamboos exert a negative influence on the plant community, our main goal was to investigate how this influence manifests at the population level. We compared the demographic structure of the threatened palm Euterpe edulis between bamboo and non-bamboo dominated patches within the Atlantic forest. In the study site, the native bamboo Guadua tagoara has created a marked patchiness and heterogeneity in the vegetation. Plots were set up randomly in bamboo and non-bamboo patches and the heights of all E. edulis individuals were measured. Data from canopy openness and litter depth were collected for both patches. Greater number of E. edulis was recorded in bamboo patches. However, frequency distribution of the height classes differed between patches revealing a predominance of seedling and sapling I classes in bamboo patches, in comparison to a more evenly distribution of height classes in non-bamboo patches. The canopy in bamboo patches was more open and the litter depth was thicker. Our analyses evidenced G. tagoara is functioning as a demographic bottleneck of natural population of E. edulis by arresting its later stages of regeneration and in high densities that bamboos may limit recruitment of this palm species.

  6. Genetic structure of an expanding Armillaria root rot fungus (Armillaria ostoyae) population in a managed pine forest in southwestern France.

    PubMed

    Prospero, S; Lung-Escarmant, B; Dutech, C

    2008-07-01

    The Landes de Gascogne forest (southwestern France) is the largest maritime pine (Pinus pinaster) plantation in Europe. Armillaria root disease (Armillaria ostoyae) has been reported since the early 1920s in the coastal area (western sector), but its incidence over the last 20 years has increased in the eastern sector. We investigated the genetic structure of the A. ostoyae population in this forest, focusing particularly on geographical differentiation potentially indicative of disease expansion in this area. In total, 531 isolates obtained from mycelial fans on symptomatic trees or undecayed stumps in 31 different disease foci were genotyped at five microsatellite loci. In 20 of these disease foci, a single genotype dominated, reflecting a predominantly clonal local spread of A. ostoyae. By contrast, at the regional scale, A. ostoyae probably spreads mostly via basidiospores (sexual spores), as no genotype common to several disease foci was identified. The absence of a clear pattern of isolation by distance may indicate either substantial gene flow or stochastic colonisation independent of spatial distance. The gradient of genetic diversity from the coast inwards and the greater genetic divergence of the eastern disease foci are consistent with the expansion of the A. ostoyae population from the coast eastwards.

  7. Inter-assemblage facilitation: the functional diversity of cavity-producing beetles drives the size diversity of cavity-nesting bees.

    PubMed

    Sydenham, Markus A K; Häusler, Lise D; Moe, Stein R; Eldegard, Katrine

    2016-01-01

    Inter-specific interactions are important drivers and maintainers of biodiversity. Compared to trophic and competitive interactions, the role of non-trophic facilitation among species has received less attention. Cavity-nesting bees nest in old beetle borings in dead wood, with restricted diameters corresponding to the body size of the bee species. The aim of this study was to test the hypothesis that the functional diversity of cavity-producing wood boring beetles - in terms of cavity diameters - drives the size diversity of cavity-nesting bees. The invertebrate communities were sampled in 30 sites, located in forested landscapes along an elevational gradient. We regressed the species richness and abundance of cavity nesting bees against the species richness and abundance of wood boring beetles, non-wood boring beetles and elevation. The proportion of cavity nesting bees in bee species assemblage was regressed against the species richness and abundance of wood boring beetles. We also tested the relationships between the size diversity of cavity nesting bees and wood boring beetles. The species richness and abundance of cavity nesting bees increased with the species richness and abundance of wood boring beetles. No such relationship was found for non-wood boring beetles. The abundance of wood boring beetles was also related to an increased proportion of cavity nesting bee individuals. Moreover, the size diversity of cavity-nesting bees increased with the functional diversity of wood boring beetles. Specifically, the mean and dispersion of bee body sizes increased with the functional dispersion of large wood boring beetles. The positive relationships between cavity producing bees and cavity nesting bees suggest that non-trophic facilitative interactions between species assemblages play important roles in organizing bee species assemblages. Considering a community-wide approach may therefore be required if we are to successfully understand and conserve wild bee

  8. Population structure, persistence, and seasonality of autochthonous Escherichia coli in temperate, coastal forest soil from a Great Lakes watershed

    USGS Publications Warehouse

    Byappanahalli, M.N.; Whitman, R.L.; Shively, D.A.; Sadowsky, M.J.; Ishii, S.

    2006-01-01

    The common occurrence of Escherichia coli in temperate soils has previously been reported, however, there are few studies to date to characterize its source, distribution, persistent capability and genetic diversity. In this study, undisturbed, forest soils within six randomly selected 0.5 m2 exclosure plots (covered by netting of 2.3 mm2 mesh size) were monitored from March to October 2003 for E. coli in order to describe its numerical and population characteristics. Culturable E. coli occurred in 88% of the samples collected, with overall mean counts of 16 MPN g-1, ranging from <1 to 1657 (n = 66). Escherichia coli counts did not correlate with substrate moisture content, air, or soil temperatures, suggesting that seasonality were not a strong factor in population density control. Mean E. coli counts in soil samples (n = 60) were significantly higher inside than immediately outside the exclosures; E. coli distribution within the exclosures was patchy. Repetitive extragenic palindromic polymerase chain reaction (Rep-PCR) demonstrated genetic heterogeneity of E. coli within and among exclosure sites, and the soil strains were genetically distinct from animal (E. coli) strains tested (i.e. gulls, terns, deer and most geese). These results suggest that E. coli can occur and persist for extended periods in undisturbed temperate forest soils independent of recent allochthonous input and season, and that the soil E. coli populations formed a cohesive phylogenetic group in comparison to the set of fecal strains with which they were compared. Thus, in assessing E. coli sources within a stream, it is important to differentiate background soil loadings from inputs derived from animal and human fecal contamination. ?? 2005 Society for Applied Microbiology and Blackwell Publishing Ltd.

  9. Population dynamics of the major north American needle-eating budworms. Forest Service research paper

    SciTech Connect

    Campbell, R.W.

    1993-04-01

    The report includes data from six western States provided 1,251 life tables representing western spruce budworm, Choristoneura occidentalis. These data provided projection capabilities for defoliation and successive budworm densities, as well as a basis for comparing survival rates among the three principal North American needle-eating budworms (western and eastern spruce budworms, and the jack pine budworm). Several modifications are suggested in current methods for managing budworm susceptible forests, and suggestions are provided for further studies on the budworm life systems.

  10. Vanishing honey bees: Is the dying of adult worker bees a consequence of short telomeres and premature aging?

    PubMed

    Stindl, Reinhard; Stindl, Wolfgang

    2010-10-01

    Einstein is often quoted to have said that without the bee, mankind would have but 4years to live. It is highly unlikely that he made this comment, which was even mentioned in a Lancet article on honey bees. However, the current vanishing of the bees can have serious consequences for human health, because 35% of the human diet is thought to benefit from pollination. Colony collapse disorder (CCD) in honey bees is characterized by the rapid decline of the adult bee population, leaving the brood and the queen poorly or completely unattended, with no dead bodies in or around the hive. A large study found no evidence that the presence or amount of any individual pesticide or infectious agent occurred more frequently or abundantly in CCD-affected colonies. The growing consensus is that honey bees are suffering from comprised immune systems, which allow various infectious pathogens to invade. The question remains, what causes immunosuppression in many colonies of Apis mellifera in North America and Europe? Telomeres are protective DNA structures located at eukaryotic chromosome tips that shorten in the somatic tissues of animals with age. Lifelong tissue regeneration takes place in Apis mellifera, and worker bees have been shown to senesce. In humans, a vast amount of literature has accumulated on exhausted telomere reserves causing impaired tissue regeneration and age-associated diseases, specifically cancer and immunosuppression. Therefore, we propose a new causative mechanism for the vanishing of the bees: critically short telomeres in long-lived winter bees. We term this the telomere premature aging syndrome. PMID:20478660

  11. A survey of bees (hymenoptera: Apoidea) of the Indiana dunes and Northwest Indiana, USA

    USGS Publications Warehouse

    Grundel, R.; Jean, R.P.; Frohnapple, K.J.; Gibbs, J.; Glowacki, G.A.; Pavlovic, N.B.

    2011-01-01

    The Indiana Dunes, and nearby natural areas in northwest Indiana, are floristically rich Midwest U.S. locales with many habitat types. We surveyed bees along a habitat gradient ranging from grasslands to forests in these locales, collecting at least 175 bee species along this gradient plus 29 additional species in other nearby habitats. About 25% of all species were from the genus Lasioglossum and 12% of the species were associated with sandy soils. Several bumblebee (Bombus) species of conservation concern that should occur in this region were not collected during our surveys. Similarity of the northwest Indiana bee fauna to other published U.S. faunas decreased about 1.3% per 100 km distance from northwest Indiana. Thirty percent of bees netted from flowers were males. Males and females differed significantly in their frequency of occurrence on different plant species. For bees collected in bowl traps, the percentage captured in fluorescent yellow traps declined and in fluorescent blue traps increased from spring to late summer. Capture rates for different bee genera varied temporally, with about a quarter of the genera being captured most frequently in late spring and a quarter in late summer. Capture rates for most genera were higher in more open than in more closed canopy habitats. The maximum number of plant species on which a single bee species was captured plateaued at 24, on average. Forty-nine percent of bee species known to occur in Indiana were found at these northwest Indiana sites. Having this relatively high proportion of the total Indiana bee fauna is consistent with Indiana Dunes existing at a biogeographic crossroads where grassland and forest biomes meet in a landscape whose climate and soils are affected by proximity to Lake Michigan. The resulting habitat, plant, edaphic, and climatic diversity likely produces the diverse bee community documented.

  12. Variation in the population structure between a natural and a human-modified forest for a pioneer tropical tree species not restricted to large gaps.

    PubMed

    Silvestrini, Milene; Dos Santos, Flavio Antonio Maës

    2015-06-01

    The distribution of tree species in tropical forests is generally related to the occurrence of disturbances and shifts in the local environmental conditions such as light, temperature, and biotic factors. Thus, the distribution of pioneer tree species is expected to vary according to the gap characteristics and with human disturbances. We asked whether there was variation in the distribution of a pioneer species under different environmental conditions generated by natural disturbances, and between two forests with contrasting levels of human disturbance. To answer this question, we studied the distribution patterns and population persistence of the pioneer tree species Croton floribundus in the size and age gap range of a primary Brazilian forest. Additionally, we compared the plant density of two size-classes between a primary and an early successional human-disturbed forest. Croton floribundus was found to be widespread and equally distributed along the gap-size gradient in the primary forest. Overall density did not vary with gap size or age (F-ratio = 0.062, P = 0.941), and while juveniles were found to have a higher density in the early successional forest (P = 0.021), tree density was found to be similar between forests (P = 0.058). Our results indicate that the population structure of a pioneer tree species with long life span and a broad gap-size niche preference varied between natural and human-disturbed forests, but not with the level of natural disturbance. We believe this can be explained by the extreme environmental changes that occur after human disturbance. The ecological processes that affect the distribution of pioneer species in natural and human-modified forests may be similar, but our results suggest they act differently under the contrasting environmental conditions generated by natural and human disturbances.

  13. Variation in the population structure between a natural and a human-modified forest for a pioneer tropical tree species not restricted to large gaps

    PubMed Central

    Silvestrini, Milene; dos Santos, Flavio Antonio Maës

    2015-01-01

    The distribution of tree species in tropical forests is generally related to the occurrence of disturbances and shifts in the local environmental conditions such as light, temperature, and biotic factors. Thus, the distribution of pioneer tree species is expected to vary according to the gap characteristics and with human disturbances. We asked whether there was variation in the distribution of a pioneer species under different environmental conditions generated by natural disturbances, and between two forests with contrasting levels of human disturbance. To answer this question, we studied the distribution patterns and population persistence of the pioneer tree species Croton floribundus in the size and age gap range of a primary Brazilian forest. Additionally, we compared the plant density of two size-classes between a primary and an early successional human-disturbed forest. Croton floribundus was found to be widespread and equally distributed along the gap-size gradient in the primary forest. Overall density did not vary with gap size or age (F-ratio = 0.062, P = 0.941), and while juveniles were found to have a higher density in the early successional forest (P = 0.021), tree density was found to be similar between forests (P = 0.058). Our results indicate that the population structure of a pioneer tree species with long life span and a broad gap-size niche preference varied between natural and human-disturbed forests, but not with the level of natural disturbance. We believe this can be explained by the extreme environmental changes that occur after human disturbance. The ecological processes that affect the distribution of pioneer species in natural and human-modified forests may be similar, but our results suggest they act differently under the contrasting environmental conditions generated by natural and human disturbances. PMID:26120431

  14. Detoxification mechanisms of honey bees (Apis mellifera) resulting in tolerance of dietary nicotine.

    PubMed

    du Rand, Esther E; Smit, Salome; Beukes, Mervyn; Apostolides, Zeno; Pirk, Christian W W; Nicolson, Susan W

    2015-01-01

    Insecticides are thought to be among the major factors contributing to current declines in bee populations. However, detoxification mechanisms in healthy, unstressed honey bees are poorly characterised. Alkaloids are naturally encountered in pollen and nectar, and we used nicotine as a model compound to identify the mechanisms involved in detoxification processes in honey bees. Nicotine and neonicotinoids have similar modes of action in insects. Our metabolomic and proteomic analyses show active detoxification of nicotine in bees, associated with increased energetic investment and also antioxidant and heat shock responses. The increased energetic investment is significant in view of the interactions of pesticides with diseases such as Nosema spp which cause energetic stress and possible malnutrition. Understanding how healthy honey bees process dietary toxins under unstressed conditions will help clarify how pesticides, alone or in synergy with other stress factors, lead to declines in bee vitality. PMID:26134631

  15. Detoxification mechanisms of honey bees (Apis mellifera) resulting in tolerance of dietary nicotine.

    PubMed

    du Rand, Esther E; Smit, Salome; Beukes, Mervyn; Apostolides, Zeno; Pirk, Christian W W; Nicolson, Susan W

    2015-07-02

    Insecticides are thought to be among the major factors contributing to current declines in bee populations. However, detoxification mechanisms in healthy, unstressed honey bees are poorly characterised. Alkaloids are naturally encountered in pollen and nectar, and we used nicotine as a model compound to identify the mechanisms involved in detoxification processes in honey bees. Nicotine and neonicotinoids have similar modes of action in insects. Our metabolomic and proteomic analyses show active detoxification of nicotine in bees, associated with increased energetic investment and also antioxidant and heat shock responses. The increased energetic investment is significant in view of the interactions of pesticides with diseases such as Nosema spp which cause energetic stress and possible malnutrition. Understanding how healthy honey bees process dietary toxins under unstressed conditions will help clarify how pesticides, alone or in synergy with other stress factors, lead to declines in bee vitality.

  16. Multifaceted responses to two major parasites in the honey bee (Apis mellifera).

    PubMed

    Wagoner, Kaira M; Boncristiani, Humberto F; Rueppell, Olav

    2013-01-01

    The recent declines in managed honey bee populations are of scientific, ecological and economic concern, and are partially attributed to honey bee parasites and related disease. McDonnell et al. investigate behavioral, chemical and neurogenomic effects of parasitization by the ectoparasite Varroa destructor and the endoparasite Nosema ceranae. The study reveals important links between underlying mechanisms of immunity and parasitization in social insects by demonstrating that chemical signals and neurogenomic states are significantly different between parasitized and non-parasitized honey bees, and that neurogenomic states are partially conserved between bees infected with distinct parasites. However the study does not reveal whether differences measured are primarily the result of adaptive host responses or of manipulation of the honey bee host by the parasites and/or confounding viral loads of parasitized individuals. Questions answered and raised by McDonnell et al. will lead to an improved understanding of honey bee health and, more generally, host-parasite interactions.

  17. Detoxification mechanisms of honey bees (Apis mellifera) resulting in tolerance of dietary nicotine

    PubMed Central

    Rand, Esther E. du; Smit, Salome; Beukes, Mervyn; Apostolides, Zeno; Pirk, Christian W.W.; Nicolson, Susan W.

    2015-01-01

    Insecticides are thought to be among the major factors contributing to current declines in bee populations. However, detoxification mechanisms in healthy, unstressed honey bees are poorly characterised. Alkaloids are naturally encountered in pollen and nectar, and we used nicotine as a model compound to identify the mechanisms involved in detoxification processes in honey bees. Nicotine and neonicotinoids have similar modes of action in insects. Our metabolomic and proteomic analyses show active detoxification of nicotine in bees, associated with increased energetic investment and also antioxidant and heat shock responses. The increased energetic investment is significant in view of the interactions of pesticides with diseases such as Nosema spp which cause energetic stress and possible malnutrition. Understanding how healthy honey bees process dietary toxins under unstressed conditions will help clarify how pesticides, alone or in synergy with other stress factors, lead to declines in bee vitality. PMID:26134631

  18. Multifaceted responses to two major parasites in the honey bee (Apis mellifera)

    PubMed Central

    2013-01-01

    The recent declines in managed honey bee populations are of scientific, ecological and economic concern, and are partially attributed to honey bee parasites and related disease. McDonnell et al. investigate behavioral, chemical and neurogenomic effects of parasitization by the ectoparasite Varroa destructor and the endoparasite Nosema ceranae. The study reveals important links between underlying mechanisms of immunity and parasitization in social insects by demonstrating that chemical signals and neurogenomic states are significantly different between parasitized and non-parasitized honey bees, and that neurogenomic states are partially conserved between bees infected with distinct parasites. However the study does not reveal whether differences measured are primarily the result of adaptive host responses or of manipulation of the honey bee host by the parasites and/or confounding viral loads of parasitized individuals. Questions answered and raised by McDonnell et al. will lead to an improved understanding of honey bee health and, more generally, host-parasite interactions. PMID:23870063

  19. Effectiveness of bowl trapping and netting for inventory of a bee community

    USGS Publications Warehouse

    Grundel, R.; Frohnapple, K.J.; Jean, R.P.; Pavlovic, N.B.

    2011-01-01

    Concern over the status of bees has increased the need to inventory bee communities and, consequently, has increased the need to understand effectiveness of different bee sampling methods. We sampled bees using bowl traps and netting at 25 northwest Indiana sites ranging from open grasslands to forests. Assemblages of bees captured in bowl traps and by netting were very similar, but this similarity was driven by similar relative abundances of commonly captured species. Less common species were often not shared between collection methods (bowls, netting) and only about half of the species were shared between methods. About one-quarter of species were more often captured by one of the two collection methods. Rapid accumulation of species was aided by sampling at temporal and habitat extremes. In particular, collecting samples early and late in the adult flight season and in open and forest habitats was effective in capturing the most species with the fewest samples. The number of samples estimated necessary to achieve a complete inventory using bowls and netting together was high. For example, ≈72% of species estimated capturable in bowls were captured among the 3,159 bees collected in bowls in this study, but ≈30,000–35,000 additional bees would need to be collected to achieve a 100% complete inventory. For bowl trapping, increasing the number of sampling dates or sampling sites was more effective than adding more bowls per sampling date in completing the inventory with the fewest specimens collected.

  20. Bee a Reader.

    ERIC Educational Resources Information Center

    Hayes, Holly, Ed.; Marmolejo, Jill, Ed.

    This publication is a tutor's guide to teaching basic literacy using The Fresno Bee, a California newspaper, as the primary "textbook." The course is aimed at English-speaking adults and is designed to teach reading in an interesting and entertaining way that promotes self-motivated study, both in the classroom and at home. The guide is divided…

  1. [Bee, wax and honey].

    PubMed

    de Laguérenne, Claude

    2003-01-01

    The archives of Nantes contain two manuscripts of the XVIIth century from which we found 63 formulae which enter bees, honey and wax. Our study concerns these various galeniques forms for internal use or external used in therapeutics and in beauty care.

  2. Changing climate and the phenological response of great tit and collared flycatcher populations in floodplain forest ecosystems in Central Europe

    NASA Astrophysics Data System (ADS)

    Bauer, Zdeněk; Trnka, Miroslav; Bauerová, Jana; Možný, Martin; Štěpánek, Petr; Bartošová, Lenka; Žalud, Zdeněk

    2010-01-01

    This study is based on 47 years of observations (1961-2007) on two common bird species, the Great Tit ( Parus major) and the Collared Flycatcher ( Ficedula albicollis), and a dominant tree species in their habitat, the English Oak ( Quercus robur). The study took place at four research sites in the Czech Republic located in full-grown, multi-aged floodplain forests with no forestry management. An increase in air temperature over the evaluated period clearly influenced the length of phenological phases. The full foliage date of English Oak has advanced by 8.7 days during the past 47 years. Great Tit and Collared Flycatcher populations have reacted to the changing climate in the same way, with first laying date and mean laying date advancing by between 6.0 and 9.0 days. In all cases, the trends are highly significant and consistent over all sites. Despite the ongoing shift in phenological stages toward the beginning of the year, the change does not appear to have led to mistiming in the trophic food chain. Overall, this study shows almost identical rates of change in egg laying dates for both bird species in all the floodplain forests studied, and these trends are coherent with those of English Oak and peak herbivorous caterpillar activity.

  3. Molecular tools and bumble bees: revealing hidden details of ecology and evolution in a model system.

    PubMed

    Woodard, S Hollis; Lozier, Jeffrey D; Goulson, David; Williams, Paul H; Strange, James P; Jha, Shalene

    2015-06-01

    Bumble bees are a longstanding model system for studies on behaviour, ecology and evolution, due to their well-studied social lifestyle, invaluable role as wild and managed pollinators, and ubiquity and diversity across temperate ecosystems. Yet despite their importance, many aspects of bumble bee biology have remained enigmatic until the rise of the genetic and, more recently, genomic eras. Here, we review and synthesize new insights into the ecology, evolution and behaviour of bumble bees that have been gained using modern genetic and genomic techniques. Special emphasis is placed on four areas of bumble bee biology: the evolution of eusociality in this group, population-level processes, large-scale evolutionary relationships and patterns, and immunity and resistance to pesticides. We close with a prospective on the future of bumble bee genomics research, as this rapidly advancing field has the potential to further revolutionize our understanding of bumble bees, particularly in regard to adaptation and resilience. Worldwide, many bumble bee populations are in decline. As such, throughout the review, connections are drawn between new molecular insights into bumble bees and our understanding of the causal factors involved in their decline. Ongoing and potential applications to bumble bee management and conservation are also included to demonstrate how genetics- and genomics-enabled research aids in the preservation of this threatened group.

  4. Molecular tools and bumble bees: revealing hidden details of ecology and evolution in a model system.

    PubMed

    Woodard, S Hollis; Lozier, Jeffrey D; Goulson, David; Williams, Paul H; Strange, James P; Jha, Shalene

    2015-06-01

    Bumble bees are a longstanding model system for studies on behaviour, ecology and evolution, due to their well-studied social lifestyle, invaluable role as wild and managed pollinators, and ubiquity and diversity across temperate ecosystems. Yet despite their importance, many aspects of bumble bee biology have remained enigmatic until the rise of the genetic and, more recently, genomic eras. Here, we review and synthesize new insights into the ecology, evolution and behaviour of bumble bees that have been gained using modern genetic and genomic techniques. Special emphasis is placed on four areas of bumble bee biology: the evolution of eusociality in this group, population-level processes, large-scale evolutionary relationships and patterns, and immunity and resistance to pesticides. We close with a prospective on the future of bumble bee genomics research, as this rapidly advancing field has the potential to further revolutionize our understanding of bumble bees, particularly in regard to adaptation and resilience. Worldwide, many bumble bee populations are in decline. As such, throughout the review, connections are drawn between new molecular insights into bumble bees and our understanding of the causal factors involved in their decline. Ongoing and potential applications to bumble bee management and conservation are also included to demonstrate how genetics- and genomics-enabled research aids in the preservation of this threatened group. PMID:25865395

  5. Rapid behavioral maturation accelerates failure of stressed honey bee colonies

    PubMed Central

    Perry, Clint J.; Myerscough, Mary R.; Barron, Andrew B.

    2015-01-01

    Many complex factors have been linked to the recent marked increase in honey bee colony failure, including pests and pathogens, agrochemicals, and nutritional stressors. It remains unclear, however, why colonies frequently react to stressors by losing almost their entire adult bee population in a short time, resulting in a colony population collapse. Here we examine the social dynamics underlying such dramatic colony failure. Bees respond to many stressors by foraging earlier in life. We manipulated the demography of experimental colonies to induce precocious foraging in bees and used radio tag tracking to examine the consequences of precocious foraging for their performance. Precocious foragers completed far fewer foraging trips in their life, and had a higher risk of death in their first flights. We constructed a demographic model to explore how this individual reaction of bees to stress might impact colony performance. In the model, when forager death rates were chronically elevated, an increasingly younger forager force caused a positive feedback that dramatically accelerated terminal population decline in the colony. This resulted in a breakdown in division of labor and loss of the adult population, leaving only brood, food, and few adults in the hive. This study explains the social processes that drive rapid depopulation of a colony, and we explore possible strategies to prevent colony failure. Understanding the process of colony failure helps identify the most effective strategies to improve colony resilience. PMID:25675508

  6. Rapid behavioral maturation accelerates failure of stressed honey bee colonies.

    PubMed

    Perry, Clint J; Søvik, Eirik; Myerscough, Mary R; Barron, Andrew B

    2015-03-17

    Many complex factors have been linked to the recent marked increase in honey bee colony failure, including pests and pathogens, agrochemicals, and nutritional stressors. It remains unclear, however, why colonies frequently react to stressors by losing almost their entire adult bee population in a short time, resulting in a colony population collapse. Here we examine the social dynamics underlying such dramatic colony failure. Bees respond to many stressors by foraging earlier in life. We manipulated the demography of experimental colonies to induce precocious foraging in bees and used radio tag tracking to examine the consequences of precocious foraging for their performance. Precocious foragers completed far fewer foraging trips in their life, and had a higher risk of death in their first flights. We constructed a demographic model to explore how this individual reaction of bees to stress might impact colony performance. In the model, when forager death rates were chronically elevated, an increasingly younger forager force caused a positive feedback that dramatically accelerated terminal population decline in the colony. This resulted in a breakdown in division of labor and loss of the adult population, leaving only brood, food, and few adults in the hive. This study explains the social processes that drive rapid depopulation of a colony, and we explore possible strategies to prevent colony failure. Understanding the process of colony failure helps identify the most effective strategies to improve colony resilience.

  7. Rapid behavioral maturation accelerates failure of stressed honey bee colonies.

    PubMed

    Perry, Clint J; Søvik, Eirik; Myerscough, Mary R; Barron, Andrew B

    2015-03-17

    Many complex factors have been linked to the recent marked increase in honey bee colony failure, including pests and pathogens, agrochemicals, and nutritional stressors. It remains unclear, however, why colonies frequently react to stressors by losing almost their entire adult bee population in a short time, resulting in a colony population collapse. Here we examine the social dynamics underlying such dramatic colony failure. Bees respond to many stressors by foraging earlier in life. We manipulated the demography of experimental colonies to induce precocious foraging in bees and used radio tag tracking to examine the consequences of precocious foraging for their performance. Precocious foragers completed far fewer foraging trips in their life, and had a higher risk of death in their first flights. We constructed a demographic model to explore how this individual reaction of bees to stress might impact colony performance. In the model, when forager death rates were chronically elevated, an increasingly younger forager force caused a positive feedback that dramatically accelerated terminal population decline in the colony. This resulted in a breakdown in division of labor and loss of the adult population, leaving only brood, food, and few adults in the hive. This study explains the social processes that drive rapid depopulation of a colony, and we explore possible strategies to prevent colony failure. Understanding the process of colony failure helps identify the most effective strategies to improve colony resilience. PMID:25675508

  8. Lessons learned by the Managed Pollinator CAP: The impact of Varroa parasitism on honey bee health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several years of work consolidated under the Cooperative Agricultural Project (CAP) has allowed a multi-institutional group of scientists to address complex questions related to the decline of honey bee populations. The group implemented a coordinated multi-state approach to improve bee management...

  9. Genomic analysis of the interaction between pesticide exposure and nutrition in honey bees (Apis mellifera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Populations of pollinators are in decline worldwide. These declines are best documented in honey bees and are due to a combination of stressors. In particular, pesticides have been linked to decreased longevity and performance in honey bees; however, the molecular and physiological pathways mediatin...

  10. The genetic population structure of wild western lowland gorillas (Gorilla gorilla gorilla) living in continuous rain forest.

    PubMed

    Fünfstück, Tillmann; Arandjelovic, Mimi; Morgan, David B; Sanz, Crickette; Breuer, Thomas; Stokes, Emma J; Reed, Patricia; Olson, Sarah H; Cameron, Ken; Ondzie, Alain; Peeters, Martine; Kühl, Hjalmar S; Cipolletta, Chloe; Todd, Angelique; Masi, Shelly; Doran-Sheehy, Diane M; Bradley, Brenda J; Vigilant, Linda

    2014-09-01

    To understand the evolutionary histories and conservation potential of wild animal species it is useful to assess whether taxa are genetically structured into different populations and identify the underlying factors responsible for any clustering. Landscape features such as rivers may influence genetic population structure, and analysis of structure by sex can further reveal effects of sex-specific dispersal. Using microsatellite genotypes obtained from noninvasively collected fecal samples we investigated the population structure of 261 western lowland gorillas (WLGs) (Gorilla gorilla gorilla) from seven locations spanning an approximately 37,000 km(2) region of mainly continuous rain forest within Central African Republic (CAR), Republic of Congo and Cameroon. We found our sample to consist of two or three significantly differentiated clusters. The boundaries of the clusters coincided with courses of major rivers. Moreover, geographic distance detoured around rivers better-explained variation in genetic distance than straight line distance. Together these results suggest that major rivers in our study area play an important role in directing WLG gene flow. The number of clusters did not change when males and females were analyzed separately, indicating a lack of greater philopatry in WLG females than males at this scale.

  11. The Genetic Population Structure of Wild Western Lowland Gorillas (Gorilla gorilla gorilla) Living in Continuous Rain Forest

    PubMed Central

    FÜNFSTÜCK, TILLMANN; ARANDJELOVIC, MIMI; MORGAN, DAVID B.; SANZ, CRICKETTE; BREUER, THOMAS; STOKES, EMMA J.; REED, PATRICIA; OLSON, SARAH H.; CAMERON, KEN; ONDZIE, ALAIN; PEETERS, MARTINE; KÜHL, HJALMAR S.; CIPOLLETTA, CHLOE; TODD, ANGELIQUE; MASI, SHELLY; DORAN-SHEEHY, DIANE M.; BRADLEY, BRENDA J.; VIGILANT, LINDA

    2014-01-01

    To understand the evolutionary histories and conservation potential of wild animal species it is useful to assess whether taxa are genetically structured into different populations and identify the underlying factors responsible for any clustering. Landscape features such as rivers may influence genetic population structure, and analysis of structure by sex can further reveal effects of sex-specific dispersal. Using microsatellite genotypes obtained from noninvasively collected fecal samples we investigated the population structure of 261 western lowland gorillas (WLGs) (Gorilla gorilla gorilla) from seven locations spanning an approximately 37,000km2 region of mainly continuous rain forest within Central African Republic (CAR), Republic of Congo and Cameroon. We found our sample to consist of two or three significantly differentiated clusters. The boundaries of the clusters coincided with courses of major rivers. Moreover, geographic distance detoured around rivers better-explained variation in genetic distance than straight line distance. Together these results suggest that major rivers in our study area play an important role in directing WLG gene flow. The number of clusters did not change when males and females were analyzed separately, indicating a lack of greater philopatry in WLG females than males at this scale. PMID:24700547

  12. The impact of rain on ice nuclei populations at a forested site in Colorado

    NASA Astrophysics Data System (ADS)

    Prenni, A. J.; Tobo, Y.; Garcia, E.; Demott, P. J.; Huffman, J. A.; McCluskey, C. S.; Kreidenweis, S. M.; Prenni, J. E.; PöHlker, C.; PöSchl, U.

    2013-01-01

    It has long been known that precipitation can impact atmospheric aerosol, altering number concentrations and size-dependent composition. Such effects result from competing mechanisms: precipitation can remove particles through wet deposition, or precipitation can lead to the emission of particles through mechanical ejection, biological processes, or re-suspension from associated wind gusts. These particles can feed back into the hydrologic cycle by serving as cloud nuclei. In this study, we investigated how precipitation at a forested site impacted the concentration and composition of ice nuclei (IN). We show that ground level IN concentrations were enhanced during rain events, with concentrations increasing by up to a factor of 40 during rain. We also show that a fraction of these IN were biological, with some of the IN identified using DNA sequencing. As these particles get entrained into the outflow of the storm, they may ultimately reach cloud levels, impacting precipitation of subsequent storms.

  13. Combined use of principal component analysis and random forests identify population-informative single nucleotide polymorphisms: application in cattle breeds.

    PubMed

    Bertolini, F; Galimberti, G; Calò, D G; Schiavo, G; Matassino, D; Fontanesi, L

    2015-10-01

    The genetic identification of the population of origin of individuals, including animals, has several practical applications in forensics, evolution, conservation genetics, breeding and authentication of animal products. Commercial high-density single nucleotide polymorphism (SNP) genotyping tools that have been recently developed in many species provide information from a large number of polymorphic sites that can be used to identify population-/breed-informative markers. In this study, starting from Illumina BovineSNP50 v1 BeadChip array genotyping data available from 3711 cattle of four breeds (2091 Italian Holstein, 738 Italian Brown, 475 Italian Simmental and 407 Marchigiana), principal component analysis (PCA) and random forests (RFs) were combined to identify informative SNP panels useful for cattle breed identification. From a PCA preselected list of 580 SNPs, RFs were computed using ranking methods (Mean Decrease in the Gini Index and Mean Accuracy Decrease) to identify the most informative 48 and 96 SNPs for breed assignment. The out-of-bag (OOB) error rate for both ranking methods and SNP densities ranged from 0.0 to 0.1% in the reference population. Application of this approach in a test population (10% of individuals pre-extracted from the whole data set) achieved 100% of correct assignment with both classifiers. Linkage disequilibrium between selected SNPs was relevant (r(2) > 0.6) only in few pairs of markers indicating that most of the selected SNPs captured different fractions of variance. Several informative SNPs were in genes/QTL regions that affect or are associated with phenotypes or production traits that might differentiate the investigated breeds. The combination of PCA and RF to perform SNP selection and breed assignment can be easily implemented and is able to identify subsets of informative SNPs useful for population assignment starting from a large number of markers derived by high-throughput genotyping platforms.

  14. Limited Pollen Dispersal Contributes to Population Genetic Structure but Not Local Adaptation in Quercus oleoides Forests of Costa Rica

    PubMed Central

    Deacon, Nicholas John; Cavender-Bares, Jeannine

    2015-01-01

    Background Quercus oleoides Cham. and Schlect., tropical live oak, is a species of conservation importance in its southern range limit of northwestern Costa Rica. It occurs in high-density stands across a fragmented landscape spanning a contrasting elevation and precipitation gradient. We examined genetic diversity and spatial genetic structure in this geographically isolated and genetically distinct population. We characterized population genetic diversity at 11 nuclear microsatellite loci in 260 individuals from 13 sites. We monitored flowering time at 10 sites, and characterized the local environment in order to compare observed spatial genetic structure to hypotheses of isolation-by-distance and isolation-by-environment. Finally, we quantified pollen dispersal distances and tested for local adaptation through a reciprocal transplant experiment in order to experimentally address these hypotheses. Results High genetic diversity is maintained in the population and the genetic variation is significantly structured among sampled sites. We identified 5 distinct genetic clusters and average pollen dispersal predominately occurred over short distances. Differences among sites in flowering phenology and environmental factors, however, were not strictly associated with genetic differentiation. Growth and survival of upland and lowland progeny in their native and foreign environments was expected to exhibit evidence of local adaptation due to the more extreme dry season in the lowlands. Seedlings planted in the lowland garden experienced much higher mortality than seedlings in the upland garden, but we did not identify evidence for local adaptation. Conclusion Overall, this study indicates that the Costa Rican Q. oleoides population has a rich population genetic history. Despite environmental heterogeneity and habitat fragmentation, isolation-by-distance and isolation-by-environment alone do not explain spatial genetic structure. These results add to studies of genetic

  15. Strategic rat control for restoring populations of native species in forest fragments.

    PubMed

    Armstrong, Doug P; Gorman, Nic; Pike, Rhonda; Kreigenhofer, Brigitte; McArthur, Nikki; Govella, Susanne; Barrett, Paul; Richard, Yvan

    2014-06-01

    Forest fragments have biodiversity value that may be enhanced through management such as control of non-native predators. However, such efforts may be ineffective, and research is needed to ensure that predator control is done strategically. We used Bayesian hierarchical modeling to estimate fragment-specific effects of experimental rat control on a native species targeted for recovery in a New Zealand pastoral landscape. The experiment was a modified BACI (before-after-control-impact) design conducted over 6 years in 19 forest fragments with low-density subpopulations of North Island Robins (Petroica longipes). The aim was to identify individual fragments that not only showed clear benefits of rat control, but also would have a high probability of subpopulation growth even if they were the only fragment managed. We collected data on fecundity, adult and juvenile survival, and juvenile emigration, and modeled the data in an integrated framework to estimate the expected annual growth rate (λ) of each subpopulation with and without rat control. Without emigration, subpopulation growth was estimated as marginal (λ = 0.95-1.05) or negative (λ = 0.74-0.90) without rat control, but it was estimated as positive in all fragments (λ = 1.4-2.1) if rats were controlled. This reflected a 150% average increase in fecundity and 45% average increase in adult female survival. The probability of a juvenile remaining in its natal fragment was 0.37 on average, but varied with fragment connectivity. With juvenile emigration added, 6 fragments were estimated to have a high (>0.8) probability of being self-sustaining (λ > 1) with rat control. The key factors affecting subpopulation growth rates under rat control were low connectivity and stock fencing because these factors were associated with lower juvenile emigration and higher fecundity, respectively. However, there was also substantial random variation in adult survival among fragments, illustrating the importance of

  16. Strategic rat control for restoring populations of native species in forest fragments.

    PubMed

    Armstrong, Doug P; Gorman, Nic; Pike, Rhonda; Kreigenhofer, Brigitte; McArthur, Nikki; Govella, Susanne; Barrett, Paul; Richard, Yvan

    2014-06-01

    Forest fragments have biodiversity value that may be enhanced through management such as control of non-native predators. However, such efforts may be ineffective, and research is needed to ensure that predator control is done strategically. We used Bayesian hierarchical modeling to estimate fragment-specific effects of experimental rat control on a native species targeted for recovery in a New Zealand pastoral landscape. The experiment was a modified BACI (before-after-control-impact) design conducted over 6 years in 19 forest fragments with low-density subpopulations of North Island Robins (Petroica longipes). The aim was to identify individual fragments that not only showed clear benefits of rat control, but also would have a high probability of subpopulation growth even if they were the only fragment managed. We collected data on fecundity, adult and juvenile survival, and juvenile emigration, and modeled the data in an integrated framework to estimate the expected annual growth rate (λ) of each subpopulation with and without rat control. Without emigration, subpopulation growth was estimated as marginal (λ = 0.95-1.05) or negative (λ = 0.74-0.90) without rat control, but it was estimated as positive in all fragments (λ = 1.4-2.1) if rats were controlled. This reflected a 150% average increase in fecundity and 45% average increase in adult female survival. The probability of a juvenile remaining in its natal fragment was 0.37 on average, but varied with fragment connectivity. With juvenile emigration added, 6 fragments were estimated to have a high (>0.8) probability of being self-sustaining (λ > 1) with rat control. The key factors affecting subpopulation growth rates under rat control were low connectivity and stock fencing because these factors were associated with lower juvenile emigration and higher fecundity, respectively. However, there was also substantial random variation in adult survival among fragments, illustrating the importance of

  17. Timing of translocation influences birth rate and population dynamics in a forest carnivore

    USGS Publications Warehouse

    Facka, Aaron N; Lewis, Jeffrey C.; Happe, Patricia; Jenkins, Kurt J.; Callas, Richard; Powell, Roger A.

    2016-01-01

    Timing can be critical for many life history events of organisms. Consequently, the timing of management activities may affect individuals and populations in numerous and unforeseen ways. Translocations of organisms are used to restore or expand populations but the timing of translocations is largely unexplored as a factor influencing population success. We hypothesized that the process of translocation negatively influences reproductive rates of individuals that are moved just before their birthing season and, therefore, the timing of releases could influence translocation success. Prior to reintroducing fishers (Pekania pennanti) into northern California and onto the Olympic Peninsula of Washington, we predicted that female fishers released in November and December (early) would have a higher probability of giving birth to kits the following March or April than females released in January, February, and March (late), just prior to or during the period of blastocyst implantation and gestation. Over four winters (2008–2011), we translocated 56 adult female fishers that could have given birth in the spring immediately after release. Denning rates, an index of birth rate, for females released early were 92% in California and 38% in Washington. In contrast, denning rates for females released late were 40% and 11%, in California and Washington, a net reduction in denning rate of 66% across both sites. To understand how releasing females nearer to parturition could influence population establishment and persistence, we used stochastic population simulations using three-stage Lefkovitch matrices. These simulations showed that translocating female fishers early had long-term positive influences on the mean population size and on quasi-extinction thresholds compared to populations where females were released late. The results from both empirical data and simulations show that the timing of translocation, with respect to life history events, should be considered during

  18. THE VISUAL ACUITY OF THE HONEY BEE.

    PubMed

    Hecht, S; Wolf, E

    1929-07-20

    1. Bees respond by a characteristic reflex to a movement in their visual field. By confining the field to a series of parallel dark and luminous bars it is possible to determine the size of bar to which the bees respond under different conditions and in this way to measure the resolving power or visual acuity of the eye. The maximum visual acuity of the bee is lower than the lowest human visual acuity. Under similar, maximal conditions the fineness of resolution of the human eye is about 100 times that of the bee. 2. The eye of the bee is a mosaic composed of hexagonal pyramids of variable apical angle. The size of this angle determines the angular separation between adjacent ommatidia and therefore sets the structural limits to the resolving power of the eye. It is found that the visual angle corresponding to the maximum visual acuity as found experimentally is identical with the structural angular separation of adjacent ommatidia in the region of maximum density of ommatidia population. When this region of maximum ommatidia population is rendered non-functional by being covered with an opaque paint, the maximum visual acuity then corresponds to the angular separation of those remaining ommatidia which now constitute the maximum density of population. 3. The angular separation of adjacent ommatidia is much smaller in the vertical (dorso-ventral) axis than in the horizontal (anterio-posterior) axis. The experimentally found visual acuity varies correspondingly. From this and other experiments as well as from the shape of the eye itself, it is shown that the bee's eye is essentially an instrument for uni-directional visual resolution, functional along the dorso-ventral axis. The resolution of the visual pattern is therefore determined by the vertical angular separation of those ocular elements situated in the region of maximum density of ommatidia population. 4. The visual acuity of the bee varies with the illumination in much the same way that it does for the human

  19. Connectivity of tiger (Panthera tigris) populations in the human-influenced forest mosaic of Central India.

    PubMed

    Joshi, Aditya; Vaidyanathan, Srinivas; Mondol, Samrat; Edgaonkar, Advait; Ramakrishnan, Uma

    2013-01-01

    Today, most wild tigers live in small, isolated Protected Areas within human dominated landscapes in the Indian subcontinent. Future survival of tigers depends on increasing local population size, as well as maintaining connectivity between populations. While significant conservation effort has been invested in increasing tiger population size, few initiatives have focused on landscape-level connectivity and on understanding the effect different landscape elements have on maintaining connectivity. We combined individual-based genetic and landscape ecology approaches to address this issue in six protected areas with varying tiger densities and separation in the Central Indian tiger landscape. We non-invasively sampled 55 tigers from different protected areas within this landscape. Maximum-likelihood and Bayesian genetic assignment tests indicate long-range tiger dispersal (on the order of 650 km) between protected areas. Further geo-spatial analyses revealed that tiger connectivity was affected by landscape elements such as human settlements, road density and host-population tiger density, but not by distance between populations. Our results elucidate the importance of landscape and habitat viability outside and between protected areas and provide a quantitative approach to test functionality of tiger corridors. We suggest future management strategies aim to minimize urban expansion between protected areas to maximize tiger connectivity. Achieving this goal in the context of ongoing urbanization and need to sustain current economic growth exerts enormous pressure on the remaining tiger habitats and emerges as a big challenge to conserve wild tigers in the Indian subcontinent.

  20. Connectivity of Tiger (Panthera tigris) Populations in the Human-Influenced Forest Mosaic of Central India

    PubMed Central

    Joshi, Aditya; Vaidyanathan, Srinivas; Mondol, Samrat; Edgaonkar, Advait; Ramakrishnan, Uma

    2013-01-01

    Today, most wild tigers live in small, isolated Protected Areas within human dominated landscapes in the Indian subcontinent. Future survival of tigers depends on increasing local population size, as well as maintaining connectivity between populations. While significant conservation effort has been invested in increasing tiger population size, few initiatives have focused on landscape-level connectivity and on understanding the effect different landscape elements have on maintaining connectivity. We combined individual-based genetic and landscape ecology approaches to address this issue in six protected areas with varying tiger densities and separation in the Central Indian tiger landscape. We non-invasively sampled 55 tigers from different protected areas within this landscape. Maximum-likelihood and Bayesian genetic assignment tests indicate long-range tiger dispersal (on the order of 650 km) between protected areas. Further geo-spatial analyses revealed that tiger connectivity was affected by landscape elements such as human settlements, road density and host-population tiger density, but not by distance between populations. Our results elucidate the importance of landscape and habitat viability outside and between protected areas and provide a quantitative approach to test functionality of tiger corridors. We suggest future management strategies aim to minimize urban expansion between protected areas to maximize tiger connectivity. Achieving this goal in the context of ongoing urbanization and need to sustain current economic growth exerts enormous pressure on the remaining tiger habitats and emerges as a big challenge to conserve wild tigers in the Indian subcontinent. PMID:24223132

  1. Connectivity of tiger (Panthera tigris) populations in the human-influenced forest mosaic of Central India.

    PubMed

    Joshi, Aditya; Vaidyanathan, Srinivas; Mondol, Samrat; Edgaonkar, Advait; Ramakrishnan, Uma

    2013-01-01

    Today, most wild tigers live in small, isolated Protected Areas within human dominated landscapes in the Indian subcontinent. Future survival of tigers depends on increasing local population size, as well as maintaining connectivity between populations. While significant conservation effort has been invested in increasing tiger population size, few initiatives have focused on landscape-level connectivity and on understanding the effect different landscape elements have on maintaining connectivity. We combined individual-based genetic and landscape ecology approaches to address this issue in six protected areas with varying tiger densities and separation in the Central Indian tiger landscape. We non-invasively sampled 55 tigers from different protected areas within this landscape. Maximum-likelihood and Bayesian genetic assignment tests indicate long-range tiger dispersal (on the order of 650 km) between protected areas. Further geo-spatial analyses revealed that tiger connectivity was affected by landscape elements such as human settlements, road density and host-population tiger density, but not by distance between populations. Our results elucidate the importance of landscape and habitat viability outside and between protected areas and provide a quantitative approach to test functionality of tiger corridors. We suggest future management strategies aim to minimize urban expansion between protected areas to maximize tiger connectivity. Achieving this goal in the context of ongoing urbanization and need to sustain current economic growth exerts enormous pressure on the remaining tiger habitats and emerges as a big challenge to conserve wild tigers in the Indian subcontinent. PMID:24223132

  2. Effects of structural complexity enhancement on eastern red-backed salamander (Plethodon cinereus) populations in northern hardwood forests

    USGS Publications Warehouse

    McKenny, H.C.; Keeton, W.S.; Donovan, T.M.

    2006-01-01

    Managing for stand structural complexity in northern hardwood forests has been proposed as a method for promoting microhabitat characteristics important to eastern red-backed salamanders (Plethodon cinereus). We evaluated the effects of alternate, structure-based silvicultural systems on red-backed salamander populations at two research sites in northwestern Vermont. Treatments included two uneven-aged approaches (single-tree selection and group-selection) and one unconventional approach, termed "structural complexity enhancement" (SCE), that promotes development of late-successional structure, including elevated levels of coarse woody debris (CWD). Treatments were applied to 2 ha units and were replicated two to four times depending on treatment. We surveyed red-backed salamanders with a natural cover search method of transects nested within vegetation plots 1 year after logging. Abundance estimates corrected for detection probability were calculated from survey data with a binomial mixture model. Abundance estimates differed between study areas and were influenced by forest structural characteristics. Model selection was conducted using Akaike Information Criteria, corrected for over-dispersed data and small sample size (QAICc). We found no difference in abundance as a response to treatment as a whole, suggesting that all of the uneven-aged silvicultural systems evaluated can maintain salamander populations after harvest. However, abundance was tied to specific structural habitat attributes associated with study plots within treatments. The most parsimonious model of habitat covariates included site, relative density of overstory trees, and density of more-decayed and less-decayed downed CWD. Abundance responded positively to the density of downed, well-decayed CWD and negatively to the density of poorly decayed CWD and to overstory relative density. CWD volume was not a strong predictor of salamander abundance. We conclude that structural complexity enhancement

  3. Long-term observation of amphibian populations inhabiting urban and forested areas in Yekaterinburg, Russia

    PubMed Central

    Vershinin, Vladimir L.; Vershinina, Svetlana D.; Berzin, Dmitry L.; Zmeeva, Darya V.; Kinev, Alexander V.

    2015-01-01

    This article presents data derived from a 36 year-long uninterrupted observational study of amphibian populations living in the city and vicinity of Yekaterinburg, Russia. This area is inhabited by six amphibian species. Based on a degree of anthropogenic transformation, the urban territory is divided into five highly mosaic zones characterized by vegetation, temperature, and a distinctive water pollution profile. Population data is presented year-by-year for the number of animals, sex ratio, and species-specific fecundity including the number and quality of spawns for the following amphibian species: Salamandrella keyserligii, Rana arvalis, R. temporaria, Lissotriton vulgaris, and Pelophylax ridibundus. These data provide an excellent opportunity to assess an urban environment from an animal population-wide perspective, as well as revealing the forces driving animal adaptation to the anthropogenic transformation of habitats. PMID:25984350

  4. Red mason bees cannot compete with honey bees for floral resources in a cage experiment.

    PubMed

    Hudewenz, Anika; Klein, Alexandra-Maria

    2015-11-01

    Intensive beekeeping to mitigate crop pollination deficits and habitat loss may cause interspecific competition between bees. Studies show negative correlations between flower visitation of honey bees (Apis mellifera) and wild bees, but effects on the reproduction of wild bees were not proven. Likely reasons are that honey bees can hardly be excluded from controls and wild bee nests are generally difficult to detect in field experiments. The goal of this study was to investigate whether red mason bees (Osmia bicornis) compete with honey bees in cages in order to compare the reproduction of red mason bees under different honey bee densities. Three treatments were applied, each replicated in four cages of 18 m³ with 38 red mason bees in all treatments and 0, 100, and 300 honey bees per treatment with 10-20% being foragers. Within the cages, the flower visitation and interspecific displacements from flowers were observed. Niche breadths and resource overlaps of both bee species were calculated, and the reproduction of red mason bees was measured. Red mason bees visited fewer flowers when honey bees were present. Niche breadth of red mason bees decreased with increasing honey bee density while resource overlaps remained constant. The reproduction of red mason bees decreased in cages with honey bees. In conclusion, our experimental results show that in small and isolated flower patches, wild bees can temporarily suffer from competition with honey bees. Further research should aim to test for competition on small and isolated flower patches in real landscapes. PMID:26640681

  5. Red mason bees cannot compete with honey bees for floral resources in a cage experiment.

    PubMed

    Hudewenz, Anika; Klein, Alexandra-Maria

    2015-11-01

    Intensive beekeeping to mitigate crop pollination deficits and habitat loss may cause interspecific competition between bees. Studies show negative correlations between flower visitation of honey bees (Apis mellifera) and wild bees, but effects on the reproduction of wild bees were not proven. Likely reasons are that honey bees can hardly be excluded from controls and wild bee nests are generally difficult to detect in field experiments. The goal of this study was to investigate whether red mason bees (Osmia bicornis) compete with honey bees in cages in order to compare the reproduction of red mason bees under different honey bee densities. Three treatments were applied, each replicated in four cages of 18 m³ with 38 red mason bees in all treatments and 0, 100, and 300 honey bees per treatment with 10-20% being foragers. Within the cages, the flower visitation and interspecific displacements from flowers were observed. Niche breadths and resource overlaps of both bee species were calculated, and the reproduction of red mason bees was measured. Red mason bees visited fewer flowers when honey bees were present. Niche breadth of red mason bees decreased with increasing honey bee density while resource overlaps remained constant. The reproduction of red mason bees decreased in cages with honey bees. In conclusion, our experimental results show that in small and isolated flower patches, wild bees can temporarily suffer from competition with honey bees. Further research should aim to test for competition on small and isolated flower patches in real landscapes.

  6. Characterizing the Impact of Commercial Pollen Substitute Diets on the Level of Nosema spp. in Honey Bees (Apis mellifera L.)

    PubMed Central

    Fleming, James C.; Schmehl, Daniel R.; Ellis, James D.

    2015-01-01

    Western honey bee (Apis mellifera L.) populations face declines commonly attributed to pesticide, pathogen, and parasite stress. One way beekeepers combat these stressors is by providing supplemental protein diets to honey bee colonies to ensure adequate colony nutrition. However Nosema spp., a microsporidian parasite of the honey bee, is thought to be associated closely with a colony’s nutritional intake, thus possibly negating any benefit the bees otherwise would have received from a nutritional supplement. Through three objectives, we examined how adult bees’ consumption of wildflower pollen or commercial pollen substitute diets affected Nosema levels in the bees’ midguts. For our first objective, we investigated how method of inoculation with Nosema affects infection levels in inoculated bees. Bees were infected with spores of Nosema four days after emergence. On day 15, bees were collected from the cages and Nosema spores were quantified. We found that inoculation through the pollen diet resulted in the highest Nosema levels in inoculated bees. In our second and third objectives, we provided the test diets to caged, newly emerged bees for a period of 15 days. Bees consuming pollen and a sucrose solution had more Nosema in their midguts than did bees consuming the sucrose solution alone (control). The overall volume of diet consumed by the bees did not correlate with the level of Nosema in their midguts. The level of Nosema was higher in bees fed certain commercial pollen substitute diets than in bees fed wildflower pollen. Our study illustrates how providing nutritional supplements to adult honey bees can impact the intensity of Nosema in their midguts. PMID:26226229

  7. Special Issue: Honey Bee Viruses.

    PubMed

    Gisder, Sebastian; Genersch, Elke

    2015-10-01

    Pollination of flowering plants is an important ecosystem service provided by wild insect pollinators and managed honey bees. Hence, losses and declines of pollinating insect species threaten human food security and are of major concern not only for apiculture or agriculture but for human society in general. Honey bee colony losses and bumblebee declines have attracted intensive research interest over the last decade and although the problem is far from being solved we now know that viruses are among the key players of many of these bee losses and bumblebee declines. With this special issue on bee viruses we, therefore, aimed to collect high quality original papers reflecting the current state of bee virus research. To this end, we focused on newly discovered viruses (Lake Sinai viruses, bee macula-like virus), or a so far neglected virus species (Apis mellifera filamentous virus), and cutting edge technologies (mass spectrometry, RNAi approach) applied in the field.

  8. Special Issue: Honey Bee Viruses

    PubMed Central

    Gisder, Sebastian; Genersch, Elke

    2015-01-01

    Pollination of flowering plants is an important ecosystem service provided by wild insect pollinators and managed honey bees. Hence, losses and declines of pollinating insect species threaten human food security and are of major concern not only for apiculture or agriculture but for human society in general. Honey bee colony losses and bumblebee declines have attracted intensive research interest over the last decade and although the problem is far from being solved we now know that viruses are among the key players of many of these bee losses and bumblebee declines. With this special issue on bee viruses we, therefore, aimed to collect high quality original papers reflecting the current state of bee virus research. To this end, we focused on newly discovered viruses (Lake Sinai viruses, bee macula-like virus), or a so far neglected virus species (Apis mellifera filamentous virus), and cutting edge technologies (mass spectrometry, RNAi approach) applied in the field. PMID:26702462

  9. Special Issue: Honey Bee Viruses.

    PubMed

    Gisder, Sebastian; Genersch, Elke

    2015-10-01

    Pollination of flowering plants is an important ecosystem service provided by wild insect pollinators and managed honey bees. Hence, losses and declines of pollinating insect species threaten human food security and are of major concern not only for apiculture or agriculture but for human society in general. Honey bee colony losses and bumblebee declines have attracted intensive research interest over the last decade and although the problem is far from being solved we now know that viruses are among the key players of many of these bee losses and bumblebee declines. With this special issue on bee viruses we, therefore, aimed to collect high quality original papers reflecting the current state of bee virus research. To this end, we focused on newly discovered viruses (Lake Sinai viruses, bee macula-like virus), or a so far neglected virus species (Apis mellifera filamentous virus), and cutting edge technologies (mass spectrometry, RNAi approach) applied in the field. PMID:26702462

  10. APIS-a novel approach for conditioning honey bees.

    PubMed

    Kirkerud, Nicholas H; Wehmann, Henja-Niniane; Galizia, C Giovanni; Gustav, David

    2013-01-01

    Honey bees perform robustly in different conditioning paradigms. This makes them excellent candidates for studying mechanisms of learning and memory at both an individual and a population level. Here we introduce a novel method of honey bee conditioning: APIS, the Automatic Performance Index System. In an enclosed walking arena where the interior is covered with an electric grid, presentation of odors from either end can be combined with weak electric shocks to form aversive associations. To quantify behavioral responses, we continuously monitor the movement of the bee by an automatic tracking system. We found that escapes from one side to the other, changes in velocity as well as distance and time spent away from the punished odor are suitable parameters to describe the bee's learning capabilities. Our data show that in a short-term memory test the response rate for the conditioned stimulus (CS) in APIS correlates well with response rate obtained from conventional Proboscis Extension Response (PER)-conditioning. Additionally, we discovered that bees modulate their behavior to aversively learned odors by reducing their rate, speed and magnitude of escapes and that both generalization and extinction seem to be different between appetitive and aversive stimuli. The advantages of this automatic system make it ideal for assessing learning rates in a standardized and convenient way, and its flexibility adds to the toolbox for studying honey bee behavior.

  11. APIS—a novel approach for conditioning honey bees

    PubMed Central

    Kirkerud, Nicholas H.; Wehmann, Henja-Niniane; Galizia, C. Giovanni; Gustav, David

    2013-01-01

    Honey bees perform robustly in different conditioning paradigms. This makes them excellent candidates for studying mechanisms of learning and memory at both an individual and a population level. Here we introduce a novel method of honey bee conditioning: APIS, the Automatic Performance Index System. In an enclosed walking arena where the interior is covered with an electric grid, presentation of odors from either end can be combined with weak electric shocks to form aversive associations. To quantify behavioral responses, we continuously monitor the movement of the bee by an automatic tracking system. We found that escapes from one side to the other, changes in velocity as well as distance and time spent away from the punished odor are suitable parameters to describe the bee's learning capabilities. Our data show that in a short-term memory test the response rate for the conditioned stimulus (CS) in APIS correlates well with response rate obtained from conventional Proboscis Extension Response (PER)-conditioning. Additionally, we discovered that bees modulate their behavior to aversively learned odors by reducing their rate, speed and magnitude of escapes and that both generalization and extinction seem to be different between appetitive and aversive stimuli. The advantages of this automatic system make it ideal for assessing learning rates in a standardized and convenient way, and its flexibility adds to the toolbox for studying honey bee behavior. PMID:23616753

  12. Effects of forest fragmentation on the winter body condition and population parameters of an habitat generalist, the wood mouse Apodemus sylvaticus: a test of hypotheses

    NASA Astrophysics Data System (ADS)

    Díaz, Mario; Santos, Tomás; Tellería, JoséLuis

    1999-02-01

    Three main causal hypotheses have been proposed to explain the inverse relationships between habitat patch size and density of generalist mouse species in fragmented habitats: 1) enhanced habitat conditions as habitat patch size decreases; 2) inhibited emigration of excess individuals in small and isolated habitat patches; and 3) reduced territoriality in small patches because they are occupied temporarily by nonreproductive individuals. From the mechanism underlying each hypothesis, we derived predictions on the effects of fragment size on the body condition of individuals (measured both as absolute body size and as body mass relative to body size) and some demographic parameters of mouse populations related to reproductive output (sex-ratio and proportions of sexually active and recently-born individuals), and we tested such predictions with data from wood mice Apodemus sylvaticus wintering in three Spanish forest archipelagos in which the inverse relationship between forest patch size and mouse abundance had been previously proven. No differences in average body size or in average body mass relative to body size were detected among fragments. Mouse populations wintering in small fragments showed more male-biased sex-ratios, a larger proportion of sexually active adults and fewer juveniles as compared to mouse populations wintering in large fragments nearby. Results clearly rejected the third hypothesis and did not support the second one. It thus seemed that habitat conditions for mice improved as forest fragment size decreased, although the expected positive effects on individuals could have been prevented by relaxed territoriality and increased food resource depletion by denser mouse populations. Bearing in mind the negative effects of dense wood mice populations on the distribution, abundance and population dynamics of forest species, this apparent enhancement of habitat conditions for mice in small forest fragments could have far-reaching consequences for the

  13. Effects of invasive parasites on bumble bee declines.

    PubMed

    Meeus, Ivan; Brown, Mark J F; De Graaf, Dirk C; Smagghe, Guy

    2011-08-01

    Bumble bees are a group of pollinators that are both ecologically and economically important and declining worldwide. Numerous mechanisms could be behind this decline, and the spread of parasites from commercial colonies into wild populations has been implicated recently in North America. Commercial breeding may lead to declines because commercial colonies may have high parasite loads, which can lead to colonization of native bumble bee populations; commercial rearing may allow higher parasite virulence to evolve; and global movement of commercial colonies may disrupt spatial patterns in local adaptation between hosts and parasites. We assessed parasite virulence, transmission mode, and infectivity. Microparasites and so-called honey bee viruses may pose the greatest threat to native bumble bee populations because certain risk factors are present; for example, the probability of horizontal transmission of the trypanosome parasite Crithidia bombi is high. The microsporidian parasite Nosema bombi may play a role in declines of bumble bees in the United States. Preliminary indications that C. bombi and the neogregarine Apicystis bombi may not be native in parts of South America. We suggest that the development of molecular screening protocols, thorough sanitation efforts, and cooperation among nongovernmental organizations, governments, and commercial breeders might immediately mitigate these threats.

  14. Effects of invasive parasites on bumble bee declines.

    PubMed

    Meeus, Ivan; Brown, Mark J F; De Graaf, Dirk C; Smagghe, Guy

    2011-08-01

    Bumble bees are a group of pollinators that are both ecologically and economically important and declining worldwide. Numerous mechanisms could be behind this decline, and the spread of parasites from commercial colonies into wild populations has been implicated recently in North America. Commercial breeding may lead to declines because commercial colonies may have high parasite loads, which can lead to colonization of native bumble bee populations; commercial rearing may allow higher parasite virulence to evolve; and global movement of commercial colonies may disrupt spatial patterns in local adaptation between hosts and parasites. We assessed parasite virulence, transmission mode, and infectivity. Microparasites and so-called honey bee viruses may pose the greatest threat to native bumble bee populations because certain risk factors are present; for example, the probability of horizontal transmission of the trypanosome parasite Crithidia bombi is high. The microsporidian parasite Nosema bombi may play a role in declines of bumble bees in the United States. Preliminary indications that C. bombi and the neogregarine Apicystis bombi may not be native in parts of South America. We suggest that the development of molecular screening protocols, thorough sanitation efforts, and cooperation among nongovernmental organizations, governments, and commercial breeders might immediately mitigate these threats. PMID:21771075

  15. Preliminary observations of autumn feeding of USDA-ARS Russian honey bees to enhance performance during almond pollination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    populous than Italian colonies and thus have less flight activity. We attempted to increase bee populations by feeding two pounds of bee-collected pollen in November to Russian and Italian colonies (n=16 each) and comparing these to unfed colonies. Flight activity of colonies in the four treatment...

  16. POPULATION OF HELICOTYLENCHUS sp AND APHELENCHUS sp NEMATODES IN THE RHIZOSPHERE OF CACAO (Theobroma cacao L.) UNDER TRADITIONAL AND IMPROVED FOREST MANAGEMENT SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematode population associated with cocoa rhizosphere was investigated at field experiment at Tropical Crop Institute (ICT) Tarapoto, San Martin-Peru. This study was carried out under two cacao management systems: traditional management system (ST) and under improved forest management system (SBB). ...

  17. The plight of the bees

    USGS Publications Warehouse

    Spivak, Marla; Mader, Eric; Vaughan, Mace; Euliss, Ned H.

    2011-01-01

    Some environmental issues polarize people, producing weary political stalemates of indecision and inaction. Others, however, grab hold of our most primeval instincts, causing us to reach deeply into our memories of childhood, and our first direct experiences with nature: the bumble bee nest we poked at with a stick; the man at the county fair with the bee beard. Those memories expand backward in time to our barefoot ancestors who climbed trees and robbed honey. They help define the human experience and provide context to our own place in the world.And so the plight of the bees strikes a common chord. For a brief moment simple matters of politics, economics, and nationality seem irrelevant. Colony collapse disorder, the name for the syndrome causing honey bees (Apis mellifera) to suddenly and mysteriously disappear from their hives - thousands of individual worker bees literally flying off to die - captured public consciousness when it was first named in 2007 (1). Since then, the story of vanishing honey bees has become ubiquitous in popular consciousness - driving everything from ice cream marketing campaigns to plots for The Simpsons. The untold story is that these hive losses are simply a capstone to more than a half-century of more prosaic day-to-day losses that beekeepers already faced from parasites, diseases, poor nutrition, and pesticide poisoning (2). The larger story still is that while honey bees are charismatic and important to agriculture, other important bees are also suffering, and in some cases their fates are far worse (3). These other bees are a subset of the roughly 4000 species of wild bumble bees (Bombus), leafcutter bees (Megachile), and others that are native to North America. While the honey bee was originally imported from Europe by colonists in the early 17th century, it is these native bees that have evolved with our local ecosystems, and, along with honey bees, are valuable crop pollinators. People want to know why bees are dying and how

  18. Wolf population in the Central Superior National Forest, 1967-1985

    USGS Publications Warehouse

    Mech, L.D.

    1986-01-01

    Aerial radio-tracking and observation showed total number of wolves per year in 2,060-km2 area varied from 35 to 87 in winter and from 30 to 78 in spring and generally declined because of a decreasing deer herd. Since winter 1977-1978, the population has remained relatively stable because an increasing proportion of it has switched to preying on moose. The number of wolves preying on deer has continued to decline.

  19. Variation in the Abundance of Neotropical Bees in an Unpredictable Seasonal Environment.

    PubMed

    Knoll, F R N

    2016-04-01

    This study provides information on the number of orchid bees based on a long-term monitoring study in an antropized savanna region in Southeastern Brazil. Sampling was carried out using chemical lures, and 77 samples were monthly collected to assess the number of individuals as well as the annual and seasonal species fluctuation. The number of species varied significantly among years but not among months, and there was a positive correlation between the number of species and the number of individuals in each sample. Monthly number counts revealed a seasonal pattern for Eulaema nigrita Lepeletier and Exaerete smaragdina Perty, which were more numerous during humid months but peaked in December, January, and February. Different species of Euglossa presented a significant variation in number among years, but not among months, with no pattern along the years. The community and the populations studied were less stable when compared to those of well-preserved habitats of equatorial forests. The El Niño phenomenon of 1997/98 did not result in negative effects in the populations studied; on the contrary, there was a peak in the number of E. nigrita. The amplitude in the yearly variation of the male orchid bee population reflects the evolutionary history of species living in unpredictable seasonal weather that led to the development of particular adaptive traits designed to deal with environmental uncertainties. This study suggests that the plasticity of the life cycle may explain population stability and provide greater resilience to severe climate change events in the future. PMID:26597968

  20. Historical and contemporary mating patterns in remnant populations of the forest tree Fraxinus excelsior L.

    PubMed

    Bacles, Cecile F E; Burczyk, Jaroslaw; Lowe, Andrew J; Ennos, Richard A

    2005-05-01

    Genetic variation at microsatellite markers was used to quantify genetic structure and mating behavior in a severely fragmented population of the wind-pollinated, wind-dispersed temperate tree Fraxinus excelsior in a deforested catchment in Scotland. Remnants maintain high levels of genetic diversity, comparable with those reported for continuous populations in southeastern Europe, and show low interpopulation differentiation (E = 0.080), indicating that historical gene exchange has not been limited (Nm = 3.48). We estimated from seeds collected from all trees producing fruits in three of five remnants that F. excelsior is predominantly outcrossing (t(m) = 0.971 +/- 0.028). Use of a neighborhood model approach to describe the relative contribution of local and long-distance pollen dispersal indicates that pollen gene flow into each of the three remnants is extensive (46-95%) and pollen dispersal has two components. The first is very localized and restricted to tens of meters around the mother trees. The second is a long-distance component with dispersal occurring over several kilometers. Effective dispersal distances, accounting for the distance and directionality to mother trees of sampled pollen donors, average 328 m and are greater than values reported for a continuous population. These results suggest that the opening of the landscape facilitates airborne pollen movement and may alleviate the expected detrimental genetic effects of fragmentation.

  1. AERIAL OVERVIEW, LOOKING WEST, WITH BEE HIVE COKE OVENS IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    AERIAL OVERVIEW, LOOKING WEST, WITH BEE HIVE COKE OVENS IN FORESTED OVERGROWTH (BOTTOM LEFT), COKE TAILINGS PILE (BOTTOM RIGHT THROUGH CENTER TOP LEFT), FORMER BIRMINGHAM SOUTHERN RAILWAY SHOPS BUILDING (TOP RIGHT). CONVICT CEMETERY IS JUST WEST OF THE TAILINGS PILE (TOP LEFT IN THIS PHOTOGRAPH). - Pratt Coal & Coke Company, Pratt Mines, Convict Cemetery, Bounded by First Street, Avenue G, Third Place & Birmingham Southern Railroad, Birmingham, Jefferson County, AL

  2. The potential conservation value of unmowed powerline strips for native bees

    USGS Publications Warehouse

    Russell, K.N.; Ikerd, H.; Droege, S.

    2005-01-01

    The land area covered by powerline easements in the United States exceeds the area of almost all national parks, including Yellowstone. In parts of Europe and the US, electric companies have altered their land management practices from periodic mowing to extraction of tall vegetation combined with the use of selective herbicides. To investigate whether this alternate management practice might produce higher quality habitat for native bees, we compared the bee fauna collected in unmowed powerline corridors and in nearby mowed grassy fields at the Patuxent Wildlife Research Center (MD). Powerline sites had more spatially and numerically rare species and a richer bee community than the grassy fields, although the difference was less pronounced than we expected. Powerline sites also had more parasitic species and more cavitynesting bees. Bee communities changed progressively through the season, but differences between the site types were persistent. The surrounding, nongrassland landscape likely has a strong influence on the bee species collected at the grassland sites, as some bees may be foraging in the grasslands but nesting elsewhere. Improving habitat for native bees will help ameliorate the loss of pollination services caused by the collapse of wild and managed honeybee populations. This study suggests that powerline strips have the potential to provide five million acres of bee-friendly habitat in the US if utilities more generally adopt appropriate management practices.

  3. Sequential generations of honey bee (Apis mellifera) queens produced using cryopreserved semen.

    PubMed

    Hopkins, Brandon K; Herr, Charles; Sheppard, Walter S

    2012-01-01

    Much of the world's food production is dependent on honey bees for pollination, and expanding food production will further increase the demand for managed pollination services. Apiculturists outside the native range of the honey bee, in the Americas, Australia and eastern Asia, have used only a few of the 27 described subspecies of honey bees (Apis mellifera) for beekeeping purposes. Within the endemic ranges of a particular subspecies, hybridisation can threaten native subspecies when local beekeepers import and propagate non-native honey bees. For many threatened species, cryopreserved germplasm can provide a resource for the preservation of diversity and recovery of endangered populations. However, although instrumental insemination of queen honey bees is well established, the absence of an effective means to cryopreserve honey bee semen has limited the success of efforts to preserve genetic diversity within the species or to develop repositories of honey bee germplasm for breeding purposes. Herein we report that some queens inseminated with cryopreserved semen were capable of producing a substantial number of fertilised offspring. These diploid female larvae were used to produce two additional sequential generations of new queens, which were then back-crossed to the same stock of frozen semen. Our results demonstrate the ability to produce queens using cryopreserved honey bee spermatozoa and the potential for the establishment of a honey bee genetic repository.

  4. Quadrat method for assessing the population abundance of a commercially managed native soil-nesting bee, Nomia melanderi (Hymenoptera: Halictidae), in proximity to alfalfa seed production in the western United States.

    PubMed

    Vinchesi, A C; Walsh, D B

    2014-08-01

    Alkali bees, Nomia melanderi Cockerell, are solitary, gregarious, soil-nesting bees native to the western United States that are commercially managed in the Walla Walla Valley of Washington State to provide pollination service on alfalfa, Medicago sativa L., produced as a seed crop. In 2010 and 2011, we compared two techniques for estimating N. melanderi abundance in commercially managed bee beds. The first technique involved quantifying the abundance of emergence holes in 24 0.5-m2 quadrats on the surface of 13 bee beds during the peak period of N. melanderi foraging activity in July of both years. When we counted emergence holes, we marked a subset of eight quadrats per bee bed with plastic tabs. Subsequently, in late October of the same year, 0.014-m3 soil cores were collected in close proximity to the plastic tabs. The soil cores were teased apart in the laboratory and the absolute abundance of overwintering prepupae was quantified per core. Simple regression was highly significant between the means of emergence holes within the 0.5-m2 soil surface quadrats and the means of the counts from the 0.014-m3 soil cores. Using mean emergence hole counts, mean prepupae counts from the soil cores, and the surface area of the bee beds, we were able to calculate the estimated abundance of N. melanderi in each bee bed. We conclude that the nondestructive quadrat method of sampling N. melanderi abundance in commercially managed beds is robust compared with the destructive, labor-intensive, absolute soil core method.

  5. Honey bee success predicted by landscape composition in Ohio, USA

    PubMed Central

    Johnson, RM

    2015-01-01

    Foraging honey bees (Apis mellifera L.) can routinely travel as far as several kilometers from their hive in the process of collecting nectar and pollen from floral patches within the surrounding landscape. Since the availability of floral resources at the landscape scale is a function of landscape composition, apiculturists have long recognized that landscape composition is a critical determinant of honey bee colony success. Nevertheless, very few studies present quantitative data relating colony success metrics to local landscape composition. We employed a beekeeper survey in conjunction with GIS-based landscape analysis to model colony success as a function of landscape composition in the State of Ohio, USA, a region characterized by intensive cropland, urban development, deciduous forest, and grassland. We found that colony food accumulation and wax production were positively related to cropland and negatively related to forest and grassland, a pattern that may be driven by the abundance of dandelion and clovers in agricultural areas compared to forest or mature grassland. Colony food accumulation was also negatively correlated with urban land cover in sites dominated by urban and agricultural land use, which does not support the popular opinion that the urban environment is more favorable to honey bees than cropland. PMID:25802808

  6. Honey bee success predicted by landscape composition in Ohio, USA.

    PubMed

    Sponsler, D B; Johnson, R M

    2015-01-01

    Foraging honey bees (Apis mellifera L.) can routinely travel as far as several kilometers from their hive in the process of collecting nectar and pollen from floral patches within the surrounding landscape. Since the availability of floral resources at the landscape scale is a function of landscape composition, apiculturists have long recognized that landscape composition is a critical determinant of honey bee colony success. Nevertheless, very few studies present quantitative data relating colony success metrics to local landscape composition. We employed a beekeeper survey in conjunction with GIS-based landscape analysis to model colony success as a function of landscape composition in the State of Ohio, USA, a region characterized by intensive cropland, urban development, deciduous forest, and grassland. We found that colony food accumulation and wax production were positively related to cropland and negatively related to forest and grassland, a pattern that may be driven by the abundance of dandelion and clovers in agricultural areas compared to forest or mature grassland. Colony food accumulation was also negatively correlated with urban land cover in sites dominated by urban and agricultural land use, which does not support the popular opinion that the urban environment is more favorable to honey bees than cropland.

  7. Honey bee success predicted by landscape composition in Ohio, USA.

    PubMed

    Sponsler, D B; Johnson, R M

    2015-01-01

    Foraging honey bees (Apis mellifera L.) can routinely travel as far as several kilometers from their hive in the process of collecting nectar and pollen from floral patches within the surrounding landscape. Since the availability of floral resources at the landscape scale is a function of landscape composition, apiculturists have long recognized that landscape composition is a critical determinant of honey bee colony success. Nevertheless, very few studies present quantitative data relating colony success metrics to local landscape composition. We employed a beekeeper survey in conjunction with GIS-based landscape analysis to model colony success as a function of landscape composition in the State of Ohio, USA, a region characterized by intensive cropland, urban development, deciduous forest, and grassland. We found that colony food accumulation and wax production were positively related to cropland and negatively related to forest and grassland, a pattern that may be driven by the abundance of dandelion and clovers in agricultural areas compared to forest or mature grassland. Colony food accumulation was also negatively correlated with urban land cover in sites dominated by urban and agricultural land use, which does not support the popular opinion that the urban environment is more favorable to honey bees than cropland. PMID:25802808

  8. Bees brought to their knees: Microbes affecting honey bee health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biology and health of the honey bee, Apis mellifera, has been of interest to human societies since the advent of beekeeping. Descriptive scientific research on pathogens affecting honey bees have been published for nearly a century, but it wasn’t until the recent outbreak of heavy colony losses...

  9. Occupancy patterns of regionally declining grassland sparrow populations in a forested Pennsylvania landscape.

    PubMed

    Hill, Jason M; Diefenbach, Duane R

    2014-06-01

    Organisms can be affected by processes in the surrounding landscape outside the boundary of habitat areas and by local vegetation characteristics. There is substantial interest in understanding how these processes affect populations of grassland birds, which have experienced substantial population declines. Much of our knowledge regarding patterns of occupancy and density stem from prairie systems, whereas relatively little is known regarding how occurrence and abundance of grassland birds vary in reclaimed surface mine grasslands. Using distance sampling and single-season occupancy models, we investigated how the occupancy probability of Grasshopper (Ammodramus savannarum) and Henslow's Sparrows (A. henslowii) on 61 surface mine grasslands (1591 ha) in Pennsylvania changed from 2002 through 2011 in response to landscape, grassland, and local vegetation characteristics . A subset (n = 23; 784 ha) of those grasslands were surveyed in 2002, and we estimated changes in sparrow density and vegetation across 10 years. Grasshopper and Henslow's Sparrow populations declined 72% and 49%, respectively from 2002 to 2011, whereas overall woody vegetation density increased 2.6 fold. Henslow's Sparrows avoided grasslands with perimeter-area ratios ≥0.141 km/ha and woody shrub densities ≥0.04 shrubs/m(2). Both species occupied grasslands ≤13 ha, but occupancy probability declined with increasing grassland perimeter-area ratio and woody shrub density. Grassland size, proximity to nearest neighboring grassland (x = 0.2 km), and surrounding landscape composition at 0.5, 1.5, and 3.0 km were not parsimonious predictors of occupancy probability for either species. Our results suggest that reclaimed surface mine grasslands, without management intervention, are ephemeral habitats for Grasshopper and Henslow's Sparrows. Given the forecasted decline in surface coal production for Pennsylvania, it is likely that both species will continue to decline in our study region for the

  10. Occupancy patterns of regionally declining grassland sparrow populations in a forested Pennsylvania landscape.

    PubMed

    Hill, Jason M; Diefenbach, Duane R

    2014-06-01

    Organisms can be affected by processes in the surrounding landscape outside the boundary of habitat areas and by local vegetation characteristics. There is substantial interest in understanding how these processes affect populations of grassland birds, which have experienced substantial population declines. Much of our knowledge regarding patterns of occupancy and density stem from prairie systems, whereas relatively little is known regarding how occurrence and abundance of grassland birds vary in reclaimed surface mine grasslands. Using distance sampling and single-season occupancy models, we investigated how the occupancy probability of Grasshopper (Ammodramus savannarum) and Henslow's Sparrows (A. henslowii) on 61 surface mine grasslands (1591 ha) in Pennsylvania changed from 2002 through 2011 in response to landscape, grassland, and local vegetation characteristics . A subset (n = 23; 784 ha) of those grasslands were surveyed in 2002, and we estimated changes in sparrow density and vegetation across 10 years. Grasshopper and Henslow's Sparrow populations declined 72% and 49%, respectively from 2002 to 2011, whereas overall woody vegetation density increased 2.6 fold. Henslow's Sparrows avoided grasslands with perimeter-area ratios ≥0.141 km/ha and woody shrub densities ≥0.04 shrubs/m(2). Both species occupied grasslands ≤13 ha, but occupancy probability declined with increasing grassland perimeter-area ratio and woody shrub density. Grassland size, proximity to nearest neighboring grassland (x = 0.2 km), and surrounding landscape composition at 0.5, 1.5, and 3.0 km were not parsimonious predictors of occupancy probability for either species. Our results suggest that reclaimed surface mine grasslands, without management intervention, are ephemeral habitats for Grasshopper and Henslow's Sparrows. Given the forecasted decline in surface coal production for Pennsylvania, it is likely that both species will continue to decline in our study region for the

  11. Evidence for Bombus occidentalis (Hymenoptera: Apidae) Populations in the Olympic Peninsula, the Palouse Prairie, and Forests of Northern Idaho

    PubMed Central

    Rhoades, Paul R.; Koch, Jonathan B.; Waits, Lisette P.; Strange, James P.; Eigenbrode, Sanford D.

    2016-01-01

    Since the mid-1990s, Bombus occidentalis (Green) has declined from being one of the most common to one of the rarest bumble bee species in the Pacific Northwest of the United States. Although its conservation status is unresolved, a petition to list this species as endangered or threatened was recently submitted to the U.S. Fish and Wildlife Service. To shed light on the conservation situation and inform the U.S. Fish and Wildlife Service decision, we report on the detection and abundance of B. occidentalis following bumble bee collection between 2012 and 2014 across the Pacific Northwest. Collection occurred from the San Juan Islands and Olympic peninsula east to northern Idaho and northeastern Oregon, excluding the arid region in central Washington. B. occidentalis was observed at 23 collection sites out of a total of 234. With the exception of three sites on the Olympic peninsula, all of these were in the southeastern portion of the collection range. PMID:26856817

  12. Evidence for Bombus occidentalis (Hymenoptera: Apidae) Populations in the Olympic Peninsula, the Palouse Prairie, and Forests of Northern Idaho.

    PubMed

    Rhoades, Paul R; Koch, Jonathan B; Waits, Lisette P; Strange, James P; Eigenbrode, Sanford D

    2016-01-01

    Since the mid-1990s, Bombus occidentalis (Green) has declined from being one of the most common to one of the rarest bumble bee species in the Pacific Northwest of the United States. Although its conservation status is unresolved, a petition to list this species as endangered or threatened was recently submitted to the U.S. Fish and Wildlife Service. To shed light on the conservation situation and inform the U.S. Fish and Wildlife Service decision, we report on the detection and abundance of B. occidentalis following bumble bee collection between 2012 and 2014 across the Pacific Northwest. Collection occurred from the San Juan Islands and Olympic peninsula east to northern Idaho and northeastern Oregon, excluding the arid region in central Washington. B. occidentalis was observed at 23 collection sites out of a total of 234. With the exception of three sites on the Olympic peninsula, all of these were in the southeastern portion of the collection range.

  13. Evidence for Bombus occidentalis (Hymenoptera: Apidae) Populations in the Olympic Peninsula, the Palouse Prairie, and Forests of Northern Idaho.

    PubMed

    Rhoades, Paul R; Koch, Jonathan B; Waits, Lisette P; Strange, James P; Eigenbrode, Sanford D

    2016-01-01

    Since the mid-1990s, Bombus occidentalis (Green) has declined from being one of the most common to one of the rarest bumble bee species in the Pacific Northwest of the United States. Although its conservation status is unresolved, a petition to list this species as endangered or threatened was recently submitted to the U.S. Fish and Wildlife Service. To shed light on the conservation situation and inform the U.S. Fish and Wildlife Service decision, we report on the detection and abundance of B. occidentalis following bumble bee collection between 2012 and 2014 across the Pacific Northwest. Collection occurred from the San Juan Islands and Olympic peninsula east to northern Idaho and northeastern Oregon, excluding the arid region in central Washington. B. occidentalis was observed at 23 collection sites out of a total of 234. With the exception of three sites on the Olympic peninsula, all of these were in the southeastern portion of the collection range. PMID:26856817

  14. Population genetic structure and trait associations in forest savory using molecular, morphological and phytochemical markers.

    PubMed

    Khadivi-Khub, Abdollah; Karimi, Ehsan; Hadian, Javad

    2014-08-10

    In this investigation, morphological, phytochemical and ISSR markers were used to estimate the relationships among and within seven populations of white savory (Satureja mutica), belonging to four provinces in Iran. The individuals were phenotypically diverse, which stamen length, corolla length, corolla diameter, calyx length, bract length, inflorescence length, calyx length and bracteole width were characteristics with the highest variation. Leaf dimensions were in significant correlation with flower and inflorescence characteristics. Chemical compounds of essential oils were found variable in various individuals and all samples were principally composed of phenolic constituents (carvacrol and/or thymol). As a consequence, the plants were classified into two major chemotypes including carvacrol and thymol. A total of 197 band positions were produced by 14 ISSR primers, of which 176 were found polymorphic with 88.91% polymorphism. ISSR genetic similarity values among individuals ranged between 0.45 and 0.94 which was indicative of a high level of genetic variation. Multiple regression analysis (MRA) revealed that phytochemical compositions as dependent variable, showed statistically significant correlation and in association with leaf and flower traits as independent variable, indicating a main role of leaf and flower on production of these compounds. Also, several ISSR fragments were found associated with some morphological traits and phytochemical compositions. The high diversity within and among populations of S. mutica according to different data systems could provide useful information for conservation and selection of cross-parents in breeding programs. PMID:24878369

  15. Wildfires in Chernobyl-contaminated forests and risks to the population and the environment: a new nuclear disaster about to happen?

    PubMed

    Evangeliou, Nikolaos; Balkanski, Yves; Cozic, Anne; Hao, Wei Min; Møller, Anders Pape

    2014-12-01

    Radioactive contamination in Ukraine, Belarus and Russia after the Chernobyl accident left large rural and forest areas to their own fate. Forest succession in conjunction with lack of forest management started gradually transforming the landscape. During the last 28 years dead wood and litter have dramatically accumulated in these areas, whereas climate change has increased temperature and favored drought. The present situation in these forests suggests an increased risk of wildfires, especially after the pronounced forest fires of 2010, which remobilized Chernobyl-deposited radioactive materials transporting them thousand kilometers far. For the aforementioned reasons, we study the consequences of different forest fires on the redistribution of (137)Cs. Using the time frequency of the fires that occurred in the area during 2010, we study three scenarios assuming that 10%, 50% and 100% of the area are burnt. We aim to sensitize the scientific community and the European authorities for the foreseen risks from radioactivity redistribution over Europe. The global model LMDZORINCA that reads deposition density of radionuclides and burnt area from satellites was used, whereas risks for the human and animal population were calculated using the Linear No-Threshold (LNT) model and the computerized software ERICA Tool, respectively. Depending on the scenario, whereas between 20 and 240 humans may suffer from solid cancers, of which 10-170 may be fatal. ERICA predicts insignificant changes in animal populations from the fires, whereas the already extreme radioactivity background plays a major role in their living quality. The resulting releases of (137)Cs after hypothetical wildfires in Chernobyl's forests are classified as high in the International Nuclear Events Scale (INES). The estimated cancer incidents and fatalities are expected to be comparable to those predicted for Fukushima. This is attributed to the fact that the distribution of radioactive fallout after the

  16. Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird.

    PubMed

    Habel, J C; Mulwa, R K; Gassert, F; Rödder, D; Ulrich, W; Borghesio, L; Husemann, M; Lens, L

    2014-09-01

    The Eastern Afromontane cloud forests occur as geographically distinct mountain exclaves. The conditions of these forests range from large to small and from fairly intact to strongly degraded. For this study, we sampled individuals of the forest bird species, the Montane White-eye Zosterops poliogaster from 16 sites and four mountain archipelagos. We analysed 12 polymorphic microsatellites and three phenotypic traits, and calculated Species Distribution Models (SDMs) to project past distributions and predict potential future range shifts under a scenario of climate warming. We found well-supported genetic and morphologic clusters corresponding to the mountain ranges where populations were sampled, with 43% of all alleles being restricted to single mountains. Our data suggest that large-scale and long-term geographic isolation on mountain islands caused genetically and morphologically distinct population clusters in Z. poliogaster. However, major genetic and biometric splits were not correlated to the geographic distances among populations. This heterogeneous pattern can be explained by past climatic shifts, as highlighted by our SDM projections. Anthropogenically fragmented populations showed lower genetic diversity and a lower mean body mass, possibly in response to suboptimal habitat conditions. On the basis of these findings and the results from our SDM analysis we predict further loss of genotypic and phenotypic uniqueness in the wake of climate change, due to the contraction of the species' climatic niche and subsequent decline in population size.

  17. Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

    PubMed Central

    Habel, J C; Mulwa, R K; Gassert, F; Rödder, D; Ulrich, W; Borghesio, L; Husemann, M; Lens, L

    2014-01-01

    The Eastern Afromontane cloud forests occur as geographically distinct mountain exclaves. The conditions of these forests range from large to small and from fairly intact to strongly degraded. For this study, we sampled individuals of the forest bird species, the Montane White-eye Zosterops poliogaster from 16 sites and four mountain archipelagos. We analysed 12 polymorphic microsatellites and three phenotypic traits, and calculated Species Distribution Models (SDMs) to project past distributions and predict potential future range shifts under a scenario of climate warming. We found well-supported genetic and morphologic clusters corresponding to the mountain ranges where populations were sampled, with 43% of all alleles being restricted to single mountains. Our data suggest that large-scale and long-term geographic isolation on mountain islands caused genetically and morphologically distinct population clusters in Z. poliogaster. However, major genetic and biometric splits were not correlated to the geographic distances among populations. This heterogeneous pattern can be explained by past climatic shifts, as highlighted by our SDM projections. Anthropogenically fragmented populations showed lower genetic diversity and a lower mean body mass, possibly in response to suboptimal habitat conditions. On the basis of these findings and the results from our SDM analysis we predict further loss of genotypic and phenotypic uniqueness in the wake of climate change, due to the contraction of the species' climatic niche and subsequent decline in population size. PMID:24713824

  18. A novel bee swarm optimization algorithm for numerical function optimization

    NASA Astrophysics Data System (ADS)

    Akbari, Reza; Mohammadi, Alireza; Ziarati, Koorush

    2010-10-01

    The optimization algorithms which are inspired from intelligent behavior of honey bees are among the most recently introduced population based techniques. In this paper, a novel algorithm called bee swarm optimization, or BSO, and its two extensions for improving its performance are presented. The BSO is a population based optimization technique which is inspired from foraging behavior of honey bees. The proposed approach provides different patterns which are used by the bees to adjust their flying trajectories. As the first extension, the BSO algorithm introduces different approaches such as repulsion factor and penalizing fitness (RP) to mitigate the stagnation problem. Second, to maintain efficiently the balance between exploration and exploitation, time-varying weights (TVW) are introduced into the BSO algorithm. The proposed algorithm (BSO) and its two extensions (BSO-RP and BSO-RPTVW) are compared with existing algorithms which are based on intelligent behavior of honey bees, on a set of well known numerical test functions. The experimental results show that the BSO algorithms are effective and robust; produce excellent results, and outperform other algorithms investigated in this consideration.

  19. Safety with Wasps and Bees.

    ERIC Educational Resources Information Center

    Hackett, Erla

    This guide is designed to provide elementary school teachers with safe learning activities concerning bees and wasps. The following topics are included: (1) the importance of a positive teacher attitude towards bees and wasps; (2) special problems posed by paper wasps; (3) what to do when a child is bothered by a wasp; (4) what to do if a wasp…

  20. Honey Bees: Sweetness and Mites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Honey bee colony losses have been in the news lately and the potential reasons for these losses have taken up much space in the news media. In order to clarify what role mites play in the current loss (2006-2007) of bee colonies, called Colony Collapse Disorder, a better understanding of what a mit...

  1. Hey! A Bee Stung Me!

    MedlinePlus

    ... from flowers. Then they turn the nectar into honey for food. Wasps are closely related to bees, but instead of only feeding on pollen and honey, wasps eat animal food, other insects, or spiders. They are not fuzzy like bees, but seem kind of smooth and shiny, and ...

  2. Varroa-tolerant Italian honey bees introduced from Brazil were not more efficient in defending themselves against the mite Varroa destructor than Carniolan bees in Germany.

    PubMed

    Corrêa-Marques, M H; De Jong, D; Rosenkranz, P; Gonçalves, L S

    2002-06-30

    In Europe and North America honey bees cannot be kept without chemical treatments against Varroa destructor. Nevertheless, in Brazil an isolated population of Italian honey bees has been kept on an island since 1984 without treatment against this mite. The infestation rates in these colonies have decreased over the years. We looked for possible varroa-tolerance factors in six Italian honey bee colonies prepared with queens from this Brazilian island population, compared to six Carniolan colonies, both tested at the same site in Germany. One such factor was the percentage of damaged mites in the colony debris, which has been reported as an indicator of colony tolerance to varroa. A mean of 35.8% of the varroa mites collected from the bottoms of the Italian bee colonies were found damaged, among which 19.1% were still alive. A significantly greater proportion of damaged mites were found in the Carniolan bees (42.3%) and 22.5% were collected alive. The most frequent kind of damage found was damaged legs alone, affecting 47.4% of the mites collected from debris in Italian bees, which was similar to the amount found in Carniolan colonies (46%). The mean infestation rate by the varroa mite in the worker brood cells in the Italian bee colonies was 3.9% in June and 3.5% in July, and in drone brood cells it was 19.3% in June. In the Carniolan honey bee colonies the mean infestation rates in worker brood cells were 3.0 and 6.7%, respectively in the months of June and July and 19.7% in drone brood cells in June. In conclusion, the 'Varroa-tolerant' Italian honey bees introduced from Brazil produced lower percentages of damaged mites (Varroa destructor) in hive debris and had similar brood infestation rates when compared to 'susceptible' Carniolan bees in Germany. In spite of the apparent adaptation of this population of Italian bees in Brazil, we found no indication of superiority of these bees when we examined the proportions of damaged mites and the varroa-infestation rates

  3. 7 CFR 322.29 - Dead bees.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Dead bees. 322.29 Section 322.29 Agriculture..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation and Transit of Restricted Articles § 322.29 Dead bees. (a) Dead bees imported into or transiting the United States must...

  4. 7 CFR 322.29 - Dead bees.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Dead bees. 322.29 Section 322.29 Agriculture..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation and Transit of Restricted Articles § 322.29 Dead bees. (a) Dead bees imported into or transiting the United States must...

  5. 7 CFR 322.29 - Dead bees.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Dead bees. 322.29 Section 322.29 Agriculture..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation and Transit of Restricted Articles § 322.29 Dead bees. (a) Dead bees imported into or transiting the United States must...

  6. 7 CFR 322.29 - Dead bees.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Dead bees. 322.29 Section 322.29 Agriculture..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation and Transit of Restricted Articles § 322.29 Dead bees. (a) Dead bees imported into or transiting the United States must...

  7. 7 CFR 322.29 - Dead bees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Dead bees. 322.29 Section 322.29 Agriculture..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation and Transit of Restricted Articles § 322.29 Dead bees. (a) Dead bees imported into or transiting the United States must...

  8. Polychlorinated biphenyls in honey bees

    SciTech Connect

    Morse, R.A.; Culliney, T.W.; Gutenmann, W.H.; Littman, C.B.; Lisk, D.J.

    1987-02-01

    Honey bees (Apis mellifera L.) may traverse a radius of several miles from their hives and contact innumerable surfaces during their collection of nectar, pollen, propolis and water. In the process, they may become contaminated with surface constituents which are indicative of the type of environmental pollution in their particular foraging area. Honey has also been analyzed as a possible indicator of heavy metal pollution. Insecticides used in the vicinity of bee hives have been found in bees and honey. It has been recently reported that appreciable concentrations of polychlorinated biphenyls (PCBs) have been found in honey bees sampled throughout Connecticut. In the work reported here, an analytical survey was conducted on PCBs in honey bees, honey, propolis and related samples in several states to learn the extent of contamination and possible sources.

  9. Extrapolation of acute toxicity across bee species.

    PubMed

    Thompson, Helen

    2016-10-01

    In applying cross-species extrapolation safety factors from honeybees to other bee species, some basic principles of toxicity have not been included, for example, the importance of body mass in determining a toxic dose. The present study re-analyzed published toxicity data, taking into account the reported mass of the individuals in the identified species. The analysis demonstrated a shift to the left in the distribution of sensitivity of honeybees relative to 20 other bee species when body size is taken into account, with the 95(th) percentile for contact and oral toxicity reducing from 10.7 (based on μg/individual bee) to 5.0 (based on μg/g bodyweight). Such an approach results in the real drivers of species differences in sensitivity-such as variability in absorption, distribution, metabolism, and excretion in and target-receptor binding-being more realistically reflected in the revised safety factor. Body mass can also be used to underpin the other parameter of first-tier risk assessment, that is, exposure. However, the key exposure factors that cannot be predicted from bodyweight are the effects of ecology and behavior of the different species on exposure to a treated crop. Further data are required to understand the biology of species associated with agricultural crops and the potential consequences of effects on individuals at the levels of the colony or bee populations. This information will allow the development of appropriate higher-tier refinement of risk assessments and testing strategies rather than extensive additional toxicity testing at Tier 1. Integr Environ Assess Manag 2016;12:622-626. © 2015 SETAC. PMID:26595163

  10. Extrapolation of acute toxicity across bee species.

    PubMed

    Thompson, Helen

    2016-10-01

    In applying cross-species extrapolation safety factors from honeybees to other bee species, some basic principles of toxicity have not been included, for example, the importance of body mass in determining a toxic dose. The present study re-analyzed published toxicity data, taking into account the reported mass of the individuals in the identified species. The analysis demonstrated a shift to the left in the distribution of sensitivity of honeybees relative to 20 other bee species when body size is taken into account, with the 95(th) percentile for contact and oral toxicity reducing from 10.7 (based on μg/individual bee) to 5.0 (based on μg/g bodyweight). Such an approach results in the real drivers of species differences in sensitivity-such as variability in absorption, distribution, metabolism, and excretion in and target-receptor binding-being more realistically reflected in the revised safety factor. Body mass can also be used to underpin the other parameter of first-tier risk assessment, that is, exposure. However, the key exposure factors that cannot be predicted from bodyweight are the effects of ecology and behavior of the different species on exposure to a treated crop. Further data are required to understand the biology of species associated with agricultural crops and the potential consequences of effects on individuals at the levels of the colony or bee populations. This information will allow the development of appropriate higher-tier refinement of risk assessments and testing strategies rather than extensive additional toxicity testing at Tier 1. Integr Environ Assess Manag 2016;12:622-626. © 2015 SETAC.

  11. Cutaneous leishmaniasis caused by Leishmania donovani in the tribal population of the Agasthyamala Biosphere Reserve forest, Western Ghats, Kerala, India.

    PubMed

    Kumar, N Pradeep; Srinivasan, R; Anish, T S; Nandakumar, G; Jambulingam, P

    2015-02-01

    Cutaneous leishmaniasis (CL), a neglected tropical disease, is reported to be prevalent in tribal villages located in the Agasthyamala Biosphere Reserve forests of Western Ghats, Kerala state, India. We carried out an investigation to characterize the species of Leishmania parasites involved in these infections prevalent among one of the oldest human tribal populations in India. Skin aspirates collected from 13 clinically diagnosed cases were subjected to histopathological investigations, serological rapid tests using 'rk39' and molecular diagnostics. Clinical manifestations recorded among the patients were hypo-pigmented erythematous nodules/papules on limbs and other parts of the body. Histopathological investigations of these skin lesions among patients showed Leishman-Donovan bodies in macrophages. None of the patients were found to be positive for rk39 tests, which detect active visceral leishmaniasis. Using three different genetic markers [kinetoplast minicircle DNA, 3' UTR region of heat-shock protein 70 (Hsp70) and Hsp70 gene] we identified the parasite species involved in these infections to be Leishmania donovani. The 6-phosphogluconate (6-PGDH) gene sequences of the parasite isolates from Western Ghats indicated close genetic relatedness to L. donovani isolates reported from Sri Lanka, also causing CL. This could be cited as another instance of 'local endemism' of organisms in this single 'bio-geographic unit'.

  12. Seasonal Variation in Population Abundance and Chytrid Infection in Stream-Dwelling Frogs of the Brazilian Atlantic Forest.

    PubMed

    Ruggeri, Joice; Longo, Ana V; Gaiarsa, Marília P; Alencar, Laura R V; Lambertini, Carolina; Leite, Domingos S; Carvalho-e-Silva, Sergio P; Zamudio, Kelly R; Toledo, Luís Felipe; Martins, Marcio

    2015-01-01

    Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae). At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd); therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis) on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation.

  13. Seasonal Variation in Population Abundance and Chytrid Infection in Stream-Dwelling Frogs of the Brazilian Atlantic Forest

    PubMed Central

    Ruggeri, Joice; Longo, Ana V.; Gaiarsa, Marília P.; Alencar, Laura R. V.; Lambertini, Carolina; Leite, Domingos S.; Carvalho-e-Silva, Sergio P.; Zamudio, Kelly R.; Toledo, Luís Felipe; Martins, Marcio

    2015-01-01

    Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae). At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd); therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis) on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation. PMID:26161777

  14. Seasonal Variation in Population Abundance and Chytrid Infection in Stream-Dwelling Frogs of the Brazilian Atlantic Forest.

    PubMed

    Ruggeri, Joice; Longo, Ana V; Gaiarsa, Marília P; Alencar, Laura R V; Lambertini, Carolina; Leite, Domingos S; Carvalho-e-Silva, Sergio P; Zamudio, Kelly R; Toledo, Luís Felipe; Martins, Marcio

    2015-01-01

    Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae). At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd); therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis) on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation. PMID:26161777

  15. Health assessment of wild lowland tapir (Tapirus terrestris) populations in the Atlantic Forest and Pantanal biomes, Brazil (1996-2012).

    PubMed

    Medici, Emília Patrícia; Mangini, Paulo Rogerio; Fernandes-Santos, Renata Carolina

    2014-10-01

    Abstract The lowland tapir (Tapirus terrestris) is found in South America and is listed as Vulnerable to Extinction by the International Union for Conservation of Nature, Red List of Threatened Species. Health issues, particularly infectious diseases, are potential threats for the species. Health information from 65 wild tapirs from two Brazilian biomes, Atlantic Forest (AF) and Pantanal (PA), were collected during a long-term study (1996-2012). The study included physic, hematologic and biochemical evaluations, microbiologic cultures, urinalysis, and serologic analyses for antibodies against 13 infectious agents (viral and bacterial). The AF and PA tapirs were significantly different for several hematologic and biochemical parameters. Ten bacteria taxa were identified in the AF and 26 in the PA. Antibodies against five viruses were detected: Bluetongue virus, eastern equine encephalitis virus, western equine encephalitis virus, infectious bovine rhinotracheitis virus, and porcine parvovirus. A high prevalence of exposure to Leptospira interrogans (10 serovars: Autumnalis, Bratislava, Canicola, Copenhageni, Grippotyphosa, Hardjo, Hebdomadis, Icterohaemorrhagiae, Pomona, and Pyrogenes) was detected in both the AF and PA sites. A greater diversity of serovars and higher antibody titers were found in the PA. Statistically significant differences between sites were found for L. interrogans, equine encephalitis virus, and porcine parvovirus. Based on physical evaluations, both AF and PA populations were healthy. The differences in the overall health profile of the AF and PA tapir populations appear to be associated with environmental factors and infectious diseases ecology. The extensive datasets on hematology, biochemistry, urinalysis, and microbiology results from this paper can be used as reference values for wild tapirs. PMID:25105810

  16. Health assessment of wild lowland tapir (Tapirus terrestris) populations in the Atlantic Forest and Pantanal biomes, Brazil (1996-2012).

    PubMed

    Medici, Emília Patrícia; Mangini, Paulo Rogerio; Fernandes-Santos, Renata Carolina

    2014-10-01

    Abstract The lowland tapir (Tapirus terrestris) is found in South America and is listed as Vulnerable to Extinction by the International Union for Conservation of Nature, Red List of Threatened Species. Health issues, particularly infectious diseases, are potential threats for the species. Health information from 65 wild tapirs from two Brazilian biomes, Atlantic Forest (AF) and Pantanal (PA), were collected during a long-term study (1996-2012). The study included physic, hematologic and biochemical evaluations, microbiologic cultures, urinalysis, and serologic analyses for antibodies against 13 infectious agents (viral and bacterial). The AF and PA tapirs were significantly different for several hematologic and biochemical parameters. Ten bacteria taxa were identified in the AF and 26 in the PA. Antibodies against five viruses were detected: Bluetongue virus, eastern equine encephalitis virus, western equine encephalitis virus, infectious bovine rhinotracheitis virus, and porcine parvovirus. A high prevalence of exposure to Leptospira interrogans (10 serovars: Autumnalis, Bratislava, Canicola, Copenhageni, Grippotyphosa, Hardjo, Hebdomadis, Icterohaemorrhagiae, Pomona, and Pyrogenes) was detected in both the AF and PA sites. A greater diversity of serovars and higher antibody titers were found in the PA. Statistically significant differences between sites were found for L. interrogans, equine encephalitis virus, and porcine parvovirus. Based on physical evaluations, both AF and PA populations were healthy. The differences in the overall health profile of the AF and PA tapir populations appear to be associated with environmental factors and infectious diseases ecology. The extensive datasets on hematology, biochemistry, urinalysis, and microbiology results from this paper can be used as reference values for wild tapirs.

  17. Heterogeneous genetic structure in a Fagus crenata population in an old-growth beech forest revealed by microsatellite markers.

    PubMed

    Asuka, Y; Tomaru, N; Nisimura, N; Tsumura, Y; Yamamoto, S

    2004-05-01

    The within-population genetic structure of Fagus crenata in a 4-ha plot (200 x 200 m) of an old-growth beech forest was analysed using microsatellite markers. To assess the genetic structure, Moran's I spatial autocorrelation coefficient was calculated. Correlograms of Moran's I showed significant positive values less than 0.100 for short-distance classes, indicating weak genetic structure. The genetic structure within the population is created by limited seed dispersal, and is probably weakened by overlapping seed shadow, secondary seed dispersal, extensive pollen flow and the thinning process. Genetic structure was detected in a western subplot of 50 x 200 m with immature soils and almost no dwarf bamboos (Sasa spp.), where small and intermediate-sized individuals were distributed in aggregations with high density because of successful regeneration. By contrast, genetic structure was not found in an eastern subplot of the same size with mature soils and Sasa cover, where successful regeneration was prevented, and the density of the small and intermediate-sized individuals was low. Moreover, genetic structure of individuals in a small-size class (diameter at breast height < 12 cm) was more obvious than in a large-size class (diameter at breast height >/= 12 cm). The apparent genetic structure detected in the 4-ha plot was therefore probably the result of the structure in the western portion of the plot and in small and intermediate-sized individuals that successfully regenerated under the favourable environment. The heterogeneity in genetic structure presumably reflects variation in the density that should be affected by differences in regeneration dynamics associated with heterogeneity in environmental conditions.

  18. An Investigation of the Migration of Africanized Honey Bees into the Southern United States

    NASA Technical Reports Server (NTRS)

    Navarro, Hector

    1997-01-01

    It is estimated that Apis mellifera scutellata, a honey bee subspecies from Africa, now extends over a 20 million square kilometer range that includes much of South America and practically all of Central America, and recently has been introduced to the southern United States. African honeybees were introduced into Brazil in 1956 by a Brazilian geneticist, Mr. Warwick Kerr. At the insistence of the Brazilian Ministry of Agriculture, in 1957, 26 colonies were accidentally released in a eucalyptus forest outside S5o Paulo. The swelling front of the bees was recorded as traveling between 80 and 500 kilometers a year. David Roubik, one of the original killer bee team members estimated that there were one trillion individual Africanized/African honey bees in Latin America. An estimate that is thought to be conservative.

  19. Honey bee pathology: current threats to honey bees and beekeeping.

    PubMed

    Genersch, Elke

    2010-06-01

    Managed honey bees are the most important commercial pollinators of those crops which depend on animal pollination for reproduction and which account for 35% of the global food production. Hence, they are vital for an economic, sustainable agriculture and for food security. In addition, honey bees also pollinate a variety of wild flowers and, therefore, contribute to the biodiversity of many ecosystems. Honey and other hive products are, at least economically and ecologically rather, by-products of beekeeping. Due to this outstanding role of honey bees, severe and inexplicable honey bee colony losses, which have been reported recently to be steadily increasing, have attracted much attention and stimulated many research activities. Although the phenomenon "decline of honey bees" is far from being finally solved, consensus exists that pests and pathogens are the single most important cause of otherwise inexplicable colony losses. This review will focus on selected bee pathogens and parasites which have been demonstrated to be involved in colony losses in different regions of the world and which, therefore, are considered current threats to honey bees and beekeeping.

  20. Hybrid origins of Australian honey bees (Apis mellifera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With increased globalisation and homogenisation the maintenance of genetic integrity of local populations of agriculturally important species is of increasing concern. The honey bee provides an interesting perspective as it is both domesticated and wild, with a large native range and much larger int...

  1. Does pathogen spillover from commercially reared bumble bees threaten wild pollinators?

    PubMed

    Otterstatter, Michael C; Thomson, James D

    2008-01-01

    The conservation of insect pollinators is drawing attention because of reported declines in bee species and the 'ecosystem services' they provide. This issue has been brought to a head by recent devastating losses of honey bees throughout North America (so called, 'Colony Collapse Disorder'); yet, we still have little understanding of the cause(s) of bee declines. Wild bumble bees (Bombus spp.) have also suffered serious declines and circumstantial evidence suggests that pathogen 'spillover' from commercially reared bumble bees, which are used extensively to pollinate greenhouse crops, is a possible cause. We constructed a spatially explicit model of pathogen spillover in bumble bees and, using laboratory experiments and the literature, estimated parameter values for the spillover of Crithidia bombi, a destructive pathogen commonly found in commercial Bombus. We also monitored wild bumble bee populations near greenhouses for evidence of pathogen spillover, and compared the fit of our model to patterns of C. bombi infection observed in the field. Our model predicts that, during the first three months of spillover, transmission from commercial hives would infect up to 20% of wild bumble bees within 2 km of the greenhouse. However, a travelling wave of disease is predicted to form suddenly, infecting up to 35-100% of wild Bombus, and spread away from the greenhouse at a rate of 2 km/wk. In the field, although we did not observe a large epizootic wave of infection, the prevalences of C. bombi near greenhouses were consistent with our model. Indeed, we found that spillover has allowed C. bombi to invade several wild bumble bee species near greenhouses. Given the available evidence, it is likely that pathogen spillover from commercial bees is contributing to the ongoing decline of wild Bombus in North America. Improved management of domestic bees, for example by reducing their parasite loads and their overlap with wild congeners, could diminish or even eliminate pathogen

  2. Non-specific dsRNA-mediated antiviral response in the honey bee.

    PubMed

    Flenniken, Michelle L; Andino, Raul

    2013-01-01

    Honey bees are essential pollinators of numerous agricultural crops. Since 2006, honey bee populations have suffered considerable annual losses that are partially attributed to Colony Collapse Disorder (CCD). CCD is an unexplained phenomenon that correlates with elevated incidence of pathogens, including RNA viruses. Honey bees are eusocial insects that live in colonies of genetically related individuals that work in concert to gather and store nutrients. Their social organization provides numerous benefits, but also facilitates pathogen transmission between individuals. To investigate honey bee antiviral defense mechanisms, we developed an RNA virus infection model and discovered that administration of dsRNA, regardless of sequence, reduced virus infection. Our results suggest that dsRNA, a viral pathogen associated molecular pattern (PAMP), triggers an antiviral response that controls virus infection in honey bees.

  3. Non-Specific dsRNA-Mediated Antiviral Response in the Honey Bee

    PubMed Central

    Flenniken, Michelle L.; Andino, Raul

    2013-01-01

    Honey bees are essential pollinators of numerous agricultural crops. Since 2006, honey bee populations have suffered considerable annual losses that are partially attributed to Colony Collapse Disorder (CCD). CCD is an unexplained phenomenon that correlates with elevated incidence of pathogens, including RNA viruses. Honey bees are eusocial insects that live in colonies of genetically related individuals that work in concert to gather and store nutrients. Their social organization provides numerous benefits, but also facilitates pathogen transmission between individuals. To investigate honey bee antiviral defense mechanisms, we developed an RNA virus infection model and discovered that administration of dsRNA, regardless of sequence, reduced virus infection. Our results suggest that dsRNA, a viral pathogen associated molecular pattern (PAMP), triggers an antiviral response that controls virus infection in honey bees. PMID:24130869

  4. A new bee species that excavates sandstone nests.

    PubMed

    Orr, Michael C; Griswold, Terry; Pitts, James P; Parker, Frank D

    2016-09-12

    Humanity has long been fascinated by animals with apparently unfavorable lifestyles [1]. Nesting habits are especially important because they can limit where organisms live, thereby driving population, community, and even ecosystem dynamics [2]. The question arises, then, why bees nest in active termite mounds [3] or on the rim of degassing volcanoes, seemingly preferring such hardship [4]. Here, we present a new bee species that excavates sandstone nests, Anthophora (Anthophoroides) pueblo Orr (described in Supplemental Information, published with this article online), despite the challenges already inherent to desert life. Ultimately, the benefits of nesting in sandstone appear to outweigh the associated costs in this system. PMID:27623257

  5. Genetic diversity in honey bee colonies enhances productivity and fitness.

    PubMed

    Mattila, Heather R; Seeley, Thomas D

    2007-07-20

    Honey bee queens mate with many males, creating numerous patrilines within colonies that are genetically distinct. The effects of genetic diversity on colony productivity and long-term fitness are unknown. We show that swarms from genetically diverse colonies (15 patrilines per colony) founded new colonies faster than swarms from genetically uniform colonies (1 patriline per colony). Accumulated differences in foraging rates, food storage, and population growth led to impressive boosts in the fitness (i.e., drone production and winter survival) of genetically diverse colonies. These results further our understanding of the origins of polyandry in honey bees and its benefits for colony performance.

  6. A new bee species that excavates sandstone nests.

    PubMed

    Orr, Michael C; Griswold, Terry; Pitts, James P; Parker, Frank D

    2016-09-12

    Humanity has long been fascinated by animals with apparently unfavorable lifestyles [1]. Nesting habits are especially important because they can limit where organisms live, thereby driving population, community, and even ecosystem dynamics [2]. The question arises, then, why bees nest in active termite mounds [3] or on the rim of degassing volcanoes, seemingly preferring such hardship [4]. Here, we present a new bee species that excavates sandstone nests, Anthophora (Anthophoroides) pueblo Orr (described in Supplemental Information, published with this article online), despite the challenges already inherent to desert life. Ultimately, the benefits of nesting in sandstone appear to outweigh the associated costs in this system.

  7. Reintroduction of the European Capercaillie from the Capercaillie Breeding Centre in Wisła Forest District: Genetic Assessments of Captive and Reintroduced Populations

    PubMed Central

    Strzała, Tomasz; Kowalczyk, Artur; Łukaszewicz, Ewa

    2015-01-01

    The Western capercaillie (Tetrao urogallus) is a specific bird species, which, despite its very broad distribution and large global population size, is highly endangered in many Western and Central European countries. According to the species situation, in many countries (including Poland), breeding and reintroduction programmes have been started. One of the most complex and large-scale reintroduction programmes was started in Bory Dolnośląskie Forest, and the Capercaillie Breeding Centre in Wisła Forest District was used as one of the sources of individuals for reintroduction. As genetic tools provide essential knowledge about species biodiversity, which is crucially important during the breeding process and reintroduction, both captive and reintroduced grouse populations were genetically analysed. We were particularly interested in genetic diversity of the individuals in both populations and the genetic relationship between them, as well as between them and other capercaillie representatives from their current range. To fulfil these goals we determined nine microsatellite loci along with a fragment of the mitochondrial control region. Genetic diversity parameters were moderate to high compared to populations from other Central and Western European countries. Both populations were clustered into three distinct genetic clades based on microsatellites. Phylogenetic analysis placed all mitochondrial haplotypes we revealed in the Eurasian clade. The present results will play an important role as they will help to preserve and maximize genetic diversity in captive populations, and will provide a basis for future monitoring of the reintroduction process. PMID:26682897

  8. Survey of bumble bee (Bombus) pathogens and parasites in Illinois and selected areas of northern California and southern Oregon.

    PubMed

    Kissinger, Christina N; Cameron, Sydney A; Thorp, Robbin W; White, Brendan; Solter, Leellen F

    2011-07-01

    Pathogens have been implicated as potential factors in the recent decline of some North American bumble bee (Bombus) species, but little information has been reported about the natural enemy complex of bumble bees in the United States. We targeted bumble bee populations in a state-wide survey in Illinois and several sites in California and Oregon where declines have been reported to determine presence and prevalence of natural enemies. Based on our observations, most parasites and pathogens appear to be widespread generalists among bumble bee species, but susceptibility to some natural enemies appeared to vary. PMID:21545804

  9. Resource Effects on Solitary Bee Reproduction in a Managed Crop Pollination System.

    PubMed

    Pitts-Singer, Theresa L

    2015-08-01

    Population density may affect solitary bee maternal resource allocation. The number of Megachile rotundata (F.), alfalfa leafcutting bee, females released for seed production of Medicago sativa L., alfalfa, may limit flower availability for nest provisioning. In turn, pollinator abundance also may affect crop yield. The M. sativa pollination system presents an opportunity to test for effects of density dependence and maternal manipulation on M. rotundata reproduction. A multiyear study was performed on M. sativa fields upon which M. rotundata densities were altered to induce low, medium, and high density situations. Numbers of adult bees and open flowers were recorded weekly; bee reproduction variables were collected once. Fields varied in plant performance for each site and year, and the intended bee densities were not realized. Therefore, the variable density index (DI) was derived to describe the number of female bees per area of flowers over the study period. As DI increased, percentages of pollinated flowers, established females, and healthy brood significantly increased, and the number of pollinated flowers per female and of dead or diseased brood significantly decreased. Sex ratio was significantly more female biased as DI increased. Overwintered offspring weights were similar regardless of DI, but significantly differed by year for both sexes, and for males also by field and year × field interaction. Overall, resource limitation was not found in this field study. Other density-dependent factors may have induced a bee dispersal response soon after bees were released in the fields that circumvented the need for, or impact of, maternal manipulation.

  10. Response of wild bees (Hymenoptera: Apoidea: Anthophila) to surrounding land cover in Wisconsin pickling cucumber.

    PubMed

    Lowenstein, D M; Huseth, A S; Groves, R L

    2012-06-01

    Cucumber (Cucumis sativus L.) is among the plants highly dependent on insect-mediated pollination, but little is known about its unmanaged pollinators. Both domestic and wild bee populations in central Wisconsin pickling cucumber fields were assessed using a combination of pan trapping and floral observations before and during bloom. Together with land cover analyses extending 2,000 m from field centers, the relationship of land cover components and bee abundance and diversity were examined. Over a 2-yr sample interval distributed among 18 experimental sites, 3,185 wild bees were collected representing >60 species. A positive association was found between both noncrop and herbaceous areas with bee abundance and diversity only during bloom. Response of bee abundance and diversity to land cover was strongest at larger buffers presumably because of the heterogeneous nature of the landscape and connectivity between crop and noncrop areas. These results are consistent with previous research that has found a weak response of wild bees to surrounding vegetation in moderately fragmented areas. A diverse community of wild bees is present within the fields of a commercial cucumber system, and there is evidence of floral visitation by unmanaged bees. This evidence emphasizes the importance of wild pollinators in fragmented landscapes and the need for additional research to investigate the effectiveness of individual species in pollen deposition. PMID:22732611

  11. Native bees mediate long-distance pollen dispersal in a shade coffee landscape mosaic.

    PubMed

    Jha, Shalene; Dick, Christopher W

    2010-08-01

    Coffee farms are often embedded within a mosaic of agriculture and forest fragments in the world's most biologically diverse tropical regions. Although shade coffee farms can potentially support native pollinator communities, the degree to which these pollinators facilitate gene flow for native trees is unknown. We examined the role of native bees as vectors of gene flow for a reproductively specialized native tree, Miconia affinis, in a shade coffee and remnant forest landscape mosaic. We demonstrate extensive cross-habitat gene flow by native bees, with pollination events spanning more than 1,800 m. Pollen was carried twice as far within shade coffee habitat as in nearby forest, and trees growing within shade coffee farms received pollen from a far greater number of sires than trees within remnant forest. The study shows that shade coffee habitats support specialized native pollinators that enhance the fecundity and genetic diversity of remnant native trees.

  12. Inbreeding in Mimulus guttatus Reduces Visitation by Bumble Bee Pollinators

    PubMed Central

    Carr, David E.; Roulston, T’ai H.; Hart, Haley

    2014-01-01

    Inbreeding in plants typically reduces individual fitness but may also alter ecological interactions. This study examined the effect of inbreeding in the mixed-mating annual Mimulus guttatus on visitation by pollinators (Bombus impatiens) in greenhouse experiments. Previous studies of M. guttatus have shown that inbreeding reduced corolla size, flower number, and pollen quantity and quality. Using controlled crosses, we produced inbred and outbred families from three different M. guttatus populations. We recorded the plant genotypes that bees visited and the number of flowers probed per visit. In our first experiment, bees were 31% more likely to visit outbred plants than those selfed for one generation and 43% more likely to visit outbred plants than those selfed for two generations. Inbreeding had only a small effect on the number of flowers probed once bees arrived at a genotype. These differences were explained partially by differences in mean floral display and mean flower size, but even when these variables were controlled statistically, the effect of inbreeding remained large and significant. In a second experiment we quantified pollen viability from inbred and self plants. Bees were 37–54% more likely to visit outbred plants, depending on the population, even when controlling for floral display size. Pollen viability proved to be as important as floral display in predicting pollinator visitation in one population, but the overall explanatory power of a multiple regression model was weak. Our data suggested that bees use cues in addition to display size, flower size, and pollen reward quality in their discrimination of inbred plants. Discrimination against inbred plants could have effects on plant fitness and thereby reinforce selection for outcrossing. Inbreeding in plant populations could also reduce resource quality for pollinators, potentially resulting in negative effects on pollinator populations. PMID:25036035

  13. Abundance and Diversity of Wild Bees (Hymenoptera: Apoidea) Found in Lowbush Blueberry Growing Regions of Downeast Maine.

    PubMed

    Bushmann, Sara L; Drummond, Francis A

    2015-08-01

    Insect-mediated pollination is critical for lowbush blueberry (Ericaceae: Vaccinium angustifolium Aiton) fruit development. Past research shows a persistent presence of wild bees (Hymenoptera: Apoidea) providing pollination services even when commercial pollinators are present. We undertook the study to 1) provide a description of bee communities found in lowbush blueberry-growing regions, 2) identify field characteristics or farm management practices that influence those communities, 3) identify key wild bee pollinators that provide pollination services for the blueberry crop, and 4) identify non-crop plants found within the cropping system that provide forage for wild bees. During a 4-year period, we collected solitary and eusocial bees in over 40 fields during and after blueberry bloom, determining a management description for each field. We collected 4,474 solitary bees representing 124 species and 1,315 summer bumble bees representing nine species. No bumble bee species were previously unknown in Maine, yet we document seven solitary bee species new for the state. These include species of the genera Nomada, Lasioglossum, Calliopsis, and Augochloropsis. No field characteristic or farm management practice related to bee community structure, except bumble bee species richness was higher in certified organic fields. Pollen analysis determined scopal loads of 67-99% ericaceous pollen carried by five species of Andrena. Our data suggest two native ericaceous plants, Kalmia angustifolia L. and Gaylussacia baccata (Wangenheim), provide important alternative floral resources. We conclude that Maine blueberry croplands are populated with a species-rich bee community that fluctuates in time and space. We suggest growers develop and maintain wild bee forage and nest sites.

  14. Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps.

    PubMed

    Lundin, Ola; Rundlöf, Maj; Smith, Henrik G; Fries, Ingemar; Bommarco, Riccardo

    2015-01-01

    It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines.

  15. Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps

    PubMed Central

    Lundin, Ola; Rundlöf, Maj; Smith, Henrik G.; Fries, Ingemar; Bommarco, Riccardo

    2015-01-01

    It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines. PMID:26313444

  16. Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps.

    PubMed

    Lundin, Ola; Rundlöf, Maj; Smith, Henrik G; Fries, Ingemar; Bommarco, Riccardo

    2015-01-01

    It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines. PMID:26313444

  17. Abundance and Diversity of Wild Bees (Hymenoptera: Apoidea) Found in Lowbush Blueberry Growing Regions of Downeast Maine.

    PubMed

    Bushmann, Sara L; Drummond, Francis A

    2015-08-01

    Insect-mediated pollination is critical for lowbush blueberry (Ericaceae: Vaccinium angustifolium Aiton) fruit development. Past research shows a persistent presence of wild bees (Hymenoptera: Apoidea) providing pollination services even when commercial pollinators are present. We undertook the study to 1) provide a description of bee communities found in lowbush blueberry-growing regions, 2) identify field characteristics or farm management practices that influence those communities, 3) identify key wild bee pollinators that provide pollination services for the blueberry crop, and 4) identify non-crop plants found within the cropping system that provide forage for wild bees. During a 4-year period, we collected solitary and eusocial bees in over 40 fields during and after blueberry bloom, determining a management description for each field. We collected 4,474 solitary bees representing 124 species and 1,315 summer bumble bees representing nine species. No bumble bee species were previously unknown in Maine, yet we document seven solitary bee species new for the state. These include species of the genera Nomada, Lasioglossum, Calliopsis, and Augochloropsis. No field characteristic or farm management practice related to bee community structure, except bumble bee species richness was higher in certified organic fields. Pollen analysis determined scopal loads of 67-99% ericaceous pollen carried by five species of Andrena. Our data suggest two native ericaceous plants, Kalmia angustifolia L. and Gaylussacia baccata (Wangenheim), provide important alternative floral resources. We conclude that Maine blueberry croplands are populated with a species-rich bee community that fluctuates in time and space. We suggest growers develop and maintain wild bee forage and nest sites. PMID:26314043

  18. Stroke after multiple bee sting.

    PubMed

    Rajendiran, C; Puvanalingam, A; Thangam, D; Ragunanthanan, S; Ramesh, D; Venkatesan, S; Sundar, C

    2012-02-01

    Bee stings are commonly encountered worldwide. Various manifestations after bee sting have been described. Local reactions are common. Unusually, manifestations like vomiting, diarrhea, dyspnea, generalized edema, acute renal failure, hypotension and collapse may occur. Rarely vasculitis, serum sickness, neuritis and encephalitis have been described which generally develop days to weeks after a sting. We report a case of a 25-year-old male who developed left sided monoparesis and transient visual loss following multiple bee stings. Unlike the previous case reports, in our case there has been involvement of both the anterior circulation and posterior circulation territory to the brain. We report this case due to it's rarity. PMID:22715562

  19. Genetic diversity and structure of wild populations of the tropical dry forest tree Jacaratia mexicana (Brassicales: Caricaceae) at a local scale in Mexico.

    PubMed

    Arias, Dulce M; Albarrán-Lara, Ana L; González-Rodríguez, Antonio; Peñaloza-Ramírez, Juan; Dorado, Oscar; Leyva, Esaú

    2012-03-01

    The tropical dry forest is a greatly endangered ecosystem, from which Jacaratia mexicana is a native tree. With the aim to assess the levels of genetic variation and population structure, four wild populations of J. mexicana were studied in the Sierra de Huautla Biosphere Reserve, Morelos, Mexico. For this, DNA was extracted from 159 individuals and were amplified with six random primers using the Random Amplified Polymorphic DNA (RAPD). A total of 54 bands were obtained, of which 50 (92.6%) were polymorphic. The total genetic diversity found within the four populations was 0.451 when estimated by Shannon's index. An AMOVA analysis showed that 84% of the total genetic variation was found within populations and 16% was among populations. The UPGMA dendrogram showed that all individuals from one of the populations (Huaxtla) formed one distinct genetic group, while the rest of the individuals did not cluster according to population. A Mantel test did not show an association between genetic and geographical distances among populations (r=0.893, p=0.20). A Bayesian cluster analysis performed with STRUCTURE, showed that the most probable number of genetic groups in the data was four (K=4), and confirmed the distinctness of Huaxtla population. Our results showed that important genetic differentiation among populations can occur even at this small geographic scale and this has to be considered in conservation actions for this genetic resource.

  20. Complementary habitat use by wild bees in agro-natural landscapes.

    PubMed

    Mandelik, Yael; Winfree, Rachael; Neeson, Thomas; Kremen, Claire

    2012-07-01

    Human activity causes abrupt changes in resource availability across the landscape. In order to persist in human-altered landscapes organisms need to shift their habitat use accordingly. Little is known about the mechanisms by which whole communities persist in human-altered landscapes, including the role of complementary habitat use. We define complementary habitat use as the use of different habitats at different times by the same group of species during the course of their activity period. We hypothesize that complementary habitat use is a mechanism through which native bee species persist in human-altered landscapes. To test this idea, we studied wild bee communities in agro-natural landscapes and explored their community-level patterns of habitat and resource use over space and time. The study was conducted in six agro-natural landscapes in the eastern United States, each containing three main bee habitat types (natural habitat, agricultural fields, and old fields). Each of the three habitats exhibited a unique seasonal pattern in amount, diversity, and composition of floral resources, and together they created phenological complementarity in foraging resources for bees. Individual bee species as well as the bee community responded to these spatiotemporal patterns in floral availability and exhibited a parallel pattern of complementary habitat use. The majority of wild bee species, including all the main crop visitors, used fallow areas within crops early in the season, shifted to crops in mid-season, and used old-field habitats later in the season. The natural-forest habitat supported very limited number of bees, mostly visitors of non-crop plants. Old fields are thus an important feature in these arable landscapes for maintaining crop pollination services. Our study provides a detailed examination of how shifts in habitat and resource use may enable bees to persist in highly dynamic agro-natural landscapes, and points to the need for a broad cross

  1. Transcriptomic and functional resources for the Small Hive Beetle Aethina tumida, a worldwide parasite of honey bees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The small hive beetle (SHB), Aethina tumida, is a major pest of managed honey bee (Apis mellifera) colonies in the United States and Australia, and an emergent threat in Europe. While strong honey bee colonies generally keep SHB populations in check, weak or stressed colonies can succumb to infestat...

  2. Statistical methods to quantify the effect of mite parasitism on the probability of death in honey bee colonies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Varroa destructor is a mite parasite of European honey bees, Apis mellifera, that weakens the population, can lead to the death of an entire honey bee colony, and is believed to be the parasite with the most economic impact on beekeeping. The purpose of this study was to estimate the probability of ...

  3. Variation in alfalfa leafcutting bee, Megachile rotundata, reproductive success according to location of nests in U.S. commercial domiciles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The alfalfa leafcutting bee, Megachile rotundata F., is used extensively to pollinate alfalfa for seed production in western North America. However, it usually is not possible to sustain bee populations in the United States. Variable microenvironments are experienced by developing alfalfa leafcutt...

  4. Crop pollination exposes honey bees to pesticides which alters their susceptibility to the gut pathogen Nosema ceranae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent declines in honey bee populations and increasing demand for insect-pollinated crops raise concerns about pollinator shortages. Pesticide exposure and pathogens may interact to have strong negative effects on managed honey bee colonies. Such findings are of great concern given the large number...

  5. <