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Sample records for aedes breeding sites

  1. Finding Aedes aegypti in a natural breeding site in an urban zone, Sao Paulo, Southeastern Brazil

    PubMed Central

    Lima-Camara, Tamara Nunes; Urbinatti, Paulo Roberto; Chiaravalloti-Neto, Francisco

    2016-01-01

    ABSTRACT This is the description of how nine Aedes aegypti larvae were found in a natural breeding site in the Pinheiros neighborhood, city of Sao Paulo, SP, Southeastern Brazil. The record was conducted in December 2014, during an entomological surveillance program of dengue virus vectors, with an active search of potential breeding sites, either artificial or natural. Finding Ae. aegypti larvae in a tree hole shows this species’ ability to use both artificial and natural environments as breeding sites and habitats, which points towards the importance of maintaining continuous surveillance on this mosquito in all kinds of water-holding containers. PMID:26982959

  2. Influence of breeding site availability on the oviposition behaviour of Aedes aegypti.

    PubMed

    Abreu, Filipe Vieira Santos de; Morais, Maira Moreira; Ribeiro, Sérvio Pontes; Eiras, Álvaro Eduardo

    2015-08-01

    Despite the importance of the mosquito Aedes aegypti in the transmission of arboviruses, such as yellow fever, Chikungunya fever and dengue fever, some aspects of their behaviour remain unknown. In the present study, the oviposition behaviour of Ae. aegypti females that were exposed to different densities of breeding sites (2, 4, 8 and 16) was evaluated in laboratory and semi-field conditions. The number of breeding sites that were used was proportional to the number available, but tended towards stabilisation. Females used four-six breeding sites on average, with a maximum of 11. A high percentage of eggs was observed in the water, along with the presence of a breeding site termed "favourite", which received at least 40% of the eggs. The results are discussed in ecological, evolutionary and epidemiological approaches. PMID:26154742

  3. Influence of breeding site availability on the oviposition behaviour of Aedes aegypti

    PubMed Central

    de Abreu, Filipe Vieira Santos; Morais, Maira Moreira; Ribeiro, Sérvio Pontes; Eiras, Álvaro Eduardo

    2015-01-01

    Despite the importance of the mosquito Aedes aegypti in the transmission of arboviruses, such as yellow fever, Chikungunya fever and dengue fever, some aspects of their behaviour remain unknown. In the present study, the oviposition behaviour of Ae. aegypti females that were exposed to different densities of breeding sites (2, 4, 8 and 16) was evaluated in laboratory and semi-field conditions. The number of breeding sites that were used was proportional to the number available, but tended towards stabilisation. Females used four-six breeding sites on average, with a maximum of 11. A high percentage of eggs was observed in the water, along with the presence of a breeding site termed “favourite”, which received at least 40% of the eggs. The results are discussed in ecological, evolutionary and epidemiological approaches. PMID:26154742

  4. Characteristics of Aedes (Stegomyia) albopictus Skuse (Diptera:Culicidae) breeding sites.

    PubMed

    Rao, B Bhaskar; Harikumar, P S; Jayakrishnan, T; George, B

    2011-09-01

    We investigated the physicochemical characteristics of Aedes albopictus Skuse viz. breeding sites, by examining coconut shells, tires and plastic containers in a chikungunya affected area of Calicut, India. The study design was a cross-sectional ecological type. Thirty-four water samples were collected randomly from coconut shells, tires and plastic containers. The larvae were counted and the water was examined. The mean number of larvae per 500 ml was significantly higher in coconut shells than in tires and plastic containers. A negative correlation was observed with pH and a positive correlation was seen with most other variables. Coconut shells were the preferred breeding site for Ae. albopictus mosquitoes in our study. The rich organic content, low illumination and small orifice of the coconut shells could be the reasons for this. The higher salinity of the coconut shells did not affect breeding or survival. PMID:22299432

  5. Breeding Sites of Aedes aegypti: Potential Dengue Vectors in Dire Dawa, East Ethiopia.

    PubMed

    Getachew, Dejene; Tekie, Habte; Gebre-Michael, Teshome; Balkew, Meshesha; Mesfin, Akalu

    2015-01-01

    Background and Objectives. Entomological survey was carried out from May-June to September-October 2014 to investigate the presence of dengue vectors in discarded tires and artificial water containers in houses and peridomestic areas. Methods. A cross-sectional immature stage survey was done indoors and outdoors in 301 houses. Mosquito larval sampling was conducted using pipette or dipper depending on container types. Larvae were identified morphologically and larval indices were also calculated. Results. A total of 750 containers were inspected, and of these 405 were positive for mosquito larvae. A total of 1,873 larvae were collected and morphologically identified as Aedes aegypti (n = 1580: 84.4%) and Culex (n = 293: 15.6%). The larval indices, house index, container index, and breteau index, varied from 33.3 to 86.2, from 23.2 to 73.9, and from 56.5 to 188.9, respectively. Conclusion. Aedes aegypti is breeding in a wide range of artificial containers. To control these mosquitoes, the integration of different methods should be taken into consideration. PMID:26435712

  6. Breeding Sites of Aedes aegypti: Potential Dengue Vectors in Dire Dawa, East Ethiopia

    PubMed Central

    Getachew, Dejene; Tekie, Habte; Gebre-Michael, Teshome; Balkew, Meshesha; Mesfin, Akalu

    2015-01-01

    Background and Objectives. Entomological survey was carried out from May-June to September-October 2014 to investigate the presence of dengue vectors in discarded tires and artificial water containers in houses and peridomestic areas. Methods. A cross-sectional immature stage survey was done indoors and outdoors in 301 houses. Mosquito larval sampling was conducted using pipette or dipper depending on container types. Larvae were identified morphologically and larval indices were also calculated. Results. A total of 750 containers were inspected, and of these 405 were positive for mosquito larvae. A total of 1,873 larvae were collected and morphologically identified as Aedes aegypti (n = 1580: 84.4%) and Culex (n = 293: 15.6%). The larval indices, house index, container index, and breteau index, varied from 33.3 to 86.2, from 23.2 to 73.9, and from 56.5 to 188.9, respectively. Conclusion. Aedes aegypti is breeding in a wide range of artificial containers. To control these mosquitoes, the integration of different methods should be taken into consideration. PMID:26435712

  7. Dry season survival of Aedes aegypti eggs in various breeding sites in the Dar es Salaam area, Tanzania*

    PubMed Central

    Trpiš, M.

    1972-01-01

    In field experiments in different breeding sites in a shaded suburban area, 7-40% of A. aegypti eggs survived a 120-day dry period. In a relatively unshaded coral area, only 3-23% of eggs survived 60 days in exposed sites, but 7-17% survived 120 days in shaded sites. Survival in some sites was higher than in the laboratory at constant conditions. PMID:4539825

  8. Aedes albopictus (Diptera: Culicidae) population size survey in the 2007 Chikungunya outbreak area in Italy. I. Characterization of breeding sites and evaluation of sampling methodologies.

    PubMed

    Carrieri, M; Angelini, P; Venturelli, C; Maccagnani, B; Bellini, R

    2011-11-01

    The population of Aedes albopictus (Skuse) (Diptera: Culicidae) was measured in four towns in northern Italy by means of Stegomyia indices (house index: percentage of houses with at least one active breeding site; container index: percentage of containers with larvae; and Breteau index: number of active breeding sites per premises), pupae per premises index (PPI), pupae per hectare index (PHI), and ovitrap monitoring. A detailed investigation on types and number of productive or potential larval habitats in the inspected premises was performed. Catch basins were the most productive breeding sites in both private and public areas. The influence of the premises maintenance and premises shading indices (PMI and PSI) on the population indices and the correlations between the latter and egg density were assessed. The highest PPI was found in badly maintained premises, most times combined with shady coverage. Stegomyia indices and PPI were well correlated with each other, but not with the PHI, which also included the pupae collected in public areas. We obtained a highly positive correlation (R = 0.86) between the PHI and weekly mean egg density estimated 7-14 d after inspection of the premises. The number of females per hectare, calculated using the Focks model, was correlated with the mean egg density of the week after sampling (R = 0.79), and we propose that ovitrap monitoring can be used to evaluate the efficiency of the control activities or to determine a mean egg density threshold for epidemic risk evaluation. PMID:22238882

  9. Temporal Dynamics and Spatial Patterns of Aedes aegypti Breeding Sites, in the Context of a Dengue Control Program in Tartagal (Salta Province, Argentina)

    PubMed Central

    Espinosa, Manuel; Weinberg, Diego; Rotela, Camilo H.; Polop, Francisco; Abril, Marcelo; Scavuzzo, Carlos Marcelo

    2016-01-01

    Background Since 2009, Fundación Mundo Sano has implemented an Aedes aegypti Surveillance and Control Program in Tartagal city (Salta Province, Argentina). The purpose of this study was to analyze temporal dynamics of Ae. aegypti breeding sites spatial distribution, during five years of samplings, and the effect of control actions over vector population dynamics. Methodology/Principal Findings Seasonal entomological (larval) samplings were conducted in 17,815 fixed sites in Tartagal urban area between 2009 and 2014. Based on information of breeding sites abundance, from satellite remote sensing data (RS), and by the use of Geographic Information Systems (GIS), spatial analysis (hotspots and cluster analysis) and predictive model (MaxEnt) were performed. Spatial analysis showed a distribution pattern with the highest breeding densities registered in city outskirts. The model indicated that 75% of Ae. aegypti distribution is explained by 3 variables: bare soil coverage percentage (44.9%), urbanization coverage percentage(13.5%) and water distribution (11.6%). Conclusions/Significance This results have called attention to the way entomological field data and information from geospatial origin (RS/GIS) are used to infer scenarios which could then be applied in epidemiological surveillance programs and in the determination of dengue control strategies. Predictive maps development constructed with Ae. aegypti systematic spatiotemporal data, in Tartagal city, would allow public health workers to identify and target high-risk areas with appropriate and timely control measures. These tools could help decision-makers to improve health system responses and preventive measures related to vector control. PMID:27223693

  10. Bdelloid rotifer, Philodina species in the breeding containers of Aedes aegypti and Aedes albopictus.

    PubMed

    Muniaraj, M; Arunachalam, N; Paramasivan, R; Mariappan, T; Philip Samuel, P; Rajamannar, V

    2012-12-01

    The vector mosquitoes of dengue and chikungunya fever, Aedes aegypti and Aedes albopictus have adapted to feed on humans and undergo larval and pupal development in natural and artificial freshwater collections. Although several studies reported, still, much information is required to understand the successful survival of Aedes mosquitoes in small temporary containers. In an investigation conducted in the chikungunya affected areas of Kerala state, India, the presence of Bdelloid rotifer, Philodina in 95% of breeding habitats of Ae. aegypti and Ae. albopictus was recorded. The role of Philodina in the breeding containers was investigated. It was found that while in control the number of Philodina was found increasing in the water sample during the study period of seven days, the number found decreased in the containers with larvae of Aedes. The gut content analysis also confirmed the presence of the rotating wheel, corona of Philodina in some of the specimen suggests its role as major larval food. PMID:23202612

  11. Infection persistence time of Aedes breeding habitats

    NASA Astrophysics Data System (ADS)

    Bicout, D. J.; Chalvet-Monfray, K.; Sabatier, P.

    2002-03-01

    The Aedes mosquito species are capable of maintaining the circulation of viruses only by the strategy of transovarial transmission and diapause of eggs. It is found that when the transovarial transmission is inhibited, the survival time of the presence of viruses in a given mosquito habitat is limited from above by the eggs lifetime. In contrast, when the transovarial transmission is turned on, the infection persistence time may largely exceed both the eggs lifetime and flooding period depending upon the production rate of infected eggs. We present a simple model allowing the derivation of analytical expressions of the infection persistence time.

  12. Better to Be in Bad Company than to Be Alone? Aedes Vectors Respond Differently to Breeding Site Quality in the Presence of Others

    PubMed Central

    Pereira, Renato N.; Godoy, Wesley A. C.

    2015-01-01

    This study focuses on two competing species, Aedes aegypti and Aedes albopictus (Diptera: Culicidae), both invasive mosquitoes of the New World. Context-specific competition between immature forms inside containers seems to be an important determinant of the coexistence or displacement of each species in different regions of the world. Here, competition experiments developed at low density (one, two or three larvae) and receiving four different resource food concentration, were designed to test whether Ae. albopictus and Ae. aegypti respond differently to competition, and whether competition can be attributed to a simple division of resources. Three phenotypic traits - larval development, adult survival under starvation and wing length - were used as indicators of performance. Larvae of neither species were limited by resource concentration when they were alone, unlike when they developed with competitors. The presence of conspecifics affected Ae. aegypti and Ae. albopictus, inducing slower development, reduced survival and wing length. The response to resource limitation was different when developing with heterospecifics: Ae. aegypti developing with one heterospecific showed faster development, producing smaller adults with shorter lives, while in the presence of two competitors, development increased and adults lived longer. Aedes albopictus demonstrated a better performance when developing with heterospecifics, with no loss in their development period and improved adult survival. Overall, our results suggest that response to competition can not simply be attributed to the division of resources, and that larvae of both species presented large phenotypic plasticity in their response to the presence or absence of heterospecifics and conspecifics. PMID:26244511

  13. Breeding patterns of Aedes stegomyia albopictus in periurban areas of Calicut, Kerala, India.

    PubMed

    Rao, B Bhaskar; George, Biju

    2010-05-01

    Aedes albopictus has been shown to be a vector for diseases which have been on the increase, such as dengue fever and chikungunya infection. We conducted a study of 100 homes from 2006-2009 to determine the breeding sites for Ae. albopictus mosquitoes in Calicut, Kerala, India. We found the larvae of Ae. albopictus mosquitoes most often in coconut shells and plastic waste, followed by tires, flower pots, glass products, egg shells and dumped grinding stones. Ae. albopictus control programs in Calicut, Kerala, India should target these objects as part of a control program. PMID:20578539

  14. Identification of Essential Containers for Aedes Larval Breeding to Control Dengue in Dhaka, Bangladesh

    PubMed Central

    Ferdousi, Farhana; Yoshimatsu, Shoji; Ma, Enbo; Sohel, Nazmul; Wagatsuma, Yukiko

    2015-01-01

    Dengue fever (DF), one of the most important emerging arboviral diseases, is transmitted through the bite of container breeding mosquitoes Aedes aegypti and Aedes albopictus. A household entomological survey was conducted in Dhaka from August through October 2000 to inspect water-holding containers in indoor, outdoor, and rooftop locations for Aedes larvae. The objective of this study was to determine mosquito productivity of each container type and to identify some risk factors of households infested with Aedes larvae. Of 9,222 households inspected, 1,306 (14.2%) were positive for Aedes larvae. Of 38,777 wet containers examined, 2,272 (5.8%) were infested with Aedes larvae. Containers used to hold water, such as earthen jars, tanks, and drums were the most common containers for larval breeding. Tires in outdoor and rooftop locations of the households were also important for larval breeding. Although present in abundance, buckets were of less importance. Factors such as independent household, presence of a water storage system in the house, and fully/partly shaded outdoors were found to be significantly associated with household infestation of Aedes larvae. Identification and subsequent elimination of the most productive containers in a given area may potentially reduce mosquito density to below a level at which dengue transmission may be halted. PMID:26865829

  15. Identification of Essential Containers for Aedes Larval Breeding to Control Dengue in Dhaka, Bangladesh.

    PubMed

    Ferdousi, Farhana; Yoshimatsu, Shoji; Ma, Enbo; Sohel, Nazmul; Wagatsuma, Yukiko

    2015-12-01

    Dengue fever (DF), one of the most important emerging arboviral diseases, is transmitted through the bite of container breeding mosquitoes Aedes aegypti and Aedes albopictus. A household entomological survey was conducted in Dhaka from August through October 2000 to inspect water-holding containers in indoor, outdoor, and rooftop locations for Aedes larvae. The objective of this study was to determine mosquito productivity of each container type and to identify some risk factors of households infested with Aedes larvae. Of 9,222 households inspected, 1,306 (14.2%) were positive for Aedes larvae. Of 38,777 wet containers examined, 2,272 (5.8%) were infested with Aedes larvae. Containers used to hold water, such as earthen jars, tanks, and drums were the most common containers for larval breeding. Tires in outdoor and rooftop locations of the households were also important for larval breeding. Although present in abundance, buckets were of less importance. Factors such as independent household, presence of a water storage system in the house, and fully/partly shaded outdoors were found to be significantly associated with household infestation of Aedes larvae. Identification and subsequent elimination of the most productive containers in a given area may potentially reduce mosquito density to below a level at which dengue transmission may be halted. PMID:26865829

  16. Socio-demographic and environmental factors associated with Aedes breeding places in Phuket, Thailand.

    PubMed

    Thammapalo, Suwich; Chongsuwiwatwong, Virasakdi; Geater, Alan; Lim, Apiradee; Choomalee, Kittisakdi

    2005-03-01

    This study aimed to determine the socio-demographic and environmental factors influencing potential breeding sites of the dengue vector in Phuket Province. Three hundred houses were recruited by cluster random sampling for larval inspection. Of all the types of water containers, a high proportion of tires and discarded items were infested by Aedes larva (42% and 32%, respectively). Due to the abundance of water tanks, jars for using water and discarded containers (1.7, 2.1, 0.8 per house), these were the main breeding sites (0.29, 0.35, and 0.28 infested containers per house, respectively). Buddhists' houses were significantly more likely to have a larvae-infested flower vase than Muslims' houses. Townhouses had relatively few infested containers, while those on rubber plantations had 18.3 times higher odds of having at least one container with larva. No window screens increased the odds of larva infestation in the discarded containers by 4.2 times. With this information and given a reliable piped water supply, the number of water containers can be reduced to minimize the breeding places. Garbage should be properly disposed of. Screens should be installed, if possible. Buddhists should be advised on the proper protection of flower vases. PMID:15916050

  17. A Sequence of Flushing and Drying of Breeding Habitats of Aedes aegypti (L.) Prior to the Low Dengue Season in Singapore

    PubMed Central

    Seidahmed, Osama M. E.; Eltahir, Elfatih A. B.

    2016-01-01

    In dengue-endemic areas, transmission shows both a seasonal and interannual variability. To investigate how rainfall impacts dengue seasonality in Singapore, we carried out a longitudinal survey in the Geylang neighborhood from August 2014 to August 2015. The survey comprised of twice-weekly random inspections to outdoor breeding habitats and continuous monitoring for positive ones. In addition, observations of rainstorms were collected. Out of 6824 inspected habitats, 67 contained Aedes aegypti, 11 contained Aedes albopictus and 24 contained Culex spp. The main outdoors habitat of Aedes aegypti was storm drains (54/67). We found that 80% of breeding sites in drains (43/54) were lost after intense rainstorms related to the wet phase of the Northeast monsoon (NE) between November 2014 and early January 2015. Subsequently, 95% (41/43) of these flushed drains had dried out during the dry phase of the NE in late January-February 2015. A return in the outdoor breeding of Aedes aegypti was observed after the onset of Southwest monsoon (SW) between May and August 2015. There was also a reduction in productivity of breeding habitats for larvae and pupae after the onset of the NE. In wet equatorial regions like Singapore, rainfall varies with the monsoons. A monsoon-driven sequence of flushing and drying shapes the outdoor seasonal abundance of Aedes aegypti. This finding can be used to optimize vector control strategies and better understand dengue in the context of climate change. PMID:27459322

  18. A Sequence of Flushing and Drying of Breeding Habitats of Aedes aegypti (L.) Prior to the Low Dengue Season in Singapore.

    PubMed

    Seidahmed, Osama M E; Eltahir, Elfatih A B

    2016-07-01

    In dengue-endemic areas, transmission shows both a seasonal and interannual variability. To investigate how rainfall impacts dengue seasonality in Singapore, we carried out a longitudinal survey in the Geylang neighborhood from August 2014 to August 2015. The survey comprised of twice-weekly random inspections to outdoor breeding habitats and continuous monitoring for positive ones. In addition, observations of rainstorms were collected. Out of 6824 inspected habitats, 67 contained Aedes aegypti, 11 contained Aedes albopictus and 24 contained Culex spp. The main outdoors habitat of Aedes aegypti was storm drains (54/67). We found that 80% of breeding sites in drains (43/54) were lost after intense rainstorms related to the wet phase of the Northeast monsoon (NE) between November 2014 and early January 2015. Subsequently, 95% (41/43) of these flushed drains had dried out during the dry phase of the NE in late January-February 2015. A return in the outdoor breeding of Aedes aegypti was observed after the onset of Southwest monsoon (SW) between May and August 2015. There was also a reduction in productivity of breeding habitats for larvae and pupae after the onset of the NE. In wet equatorial regions like Singapore, rainfall varies with the monsoons. A monsoon-driven sequence of flushing and drying shapes the outdoor seasonal abundance of Aedes aegypti. This finding can be used to optimize vector control strategies and better understand dengue in the context of climate change. PMID:27459322

  19. Categorization of potential breeding sites of dengue vectors in Johor, Malaysia.

    PubMed

    Nyamah, M A; Sulaiman, S; Omar, B

    2010-04-01

    This cross-sectional study was to compare and categorize potential breeding sites of dengue vectors, Aedes aegypti and Aedes albopictus at three different places, namely, an urban (Taman Permas Jaya, Johor Bahru, Johor), a suburban (Kg. Melayu Gelang Patah, Johor Bahru, Johor) and a rural (Felda Simpang Waha, Kota Tinggi, Johor) habitats in Malaysia. Larval surveys were conducted once in every two months at each habitat over a period of 11 months from August 2000 until June 2001. There was a significant difference between the three study sites in terms of potential breeding sites inspected (p<0.001). There were more potential breeding sites found in the rural area when compared to the urban and suburban habitats. The mean Potential Container Index (PCI) values in descending order were as follows: rural habitat (57.72)>suburban (29.35)>urban habitat (16.97). Both breeding sites and potential breeding sites were the nominator and the total number of containers inspected as the denominator in the formula of PCI, thus the latter could be a potential indicator to initiate anti-dengue campaign at the community level to rid off potential Aedes breeding sites. The three most common potential breeding sites of Aedes species were similar for urban and suburban habitats (flower pots, pails and bowls respectively). However, flower pots, vases and tyres were the three most common potential breeding sites for the rural habitat. Another finding in this study was that various types of larval habitats were found indoors and outdoors for both species. PMID:20562811

  20. Further extension of the range of the rock pool mosquito, Aedes atropalpus, via tire breeding.

    PubMed

    Nawrocki, S J; Craig, G B

    1989-03-01

    In the past, Aedes atropalpus was limited to those areas of the eastern U.S. and Canada that had rivers or shorelines with large rocks containing rock pools. In the last 10 years, many new records of larval breeding in scrap tires have accumulated. We present records of larval breeding in non-rock pool containers for 54 counties; most are far from the original range. The species has not only found a new habitat but has greatly extended its range via commercial transport of scrap tires. PMID:2708986

  1. Prevalence of Ascogregarina spp. in the container breeding Aedes albopictus from Chikungunya fever affected areas of Kerala State, India.

    PubMed

    Muniaraj, M; Rajendran, R; Arunachalam, N; Paramasivan, R; Samuel, P Philip

    2010-06-01

    The prevalence of protozoan, Ascogregarina sp. had been determined in the container breeding mosquitoes, Aedes albopictus. Since, the cyst of Ascogregarina might play role in the maintenance of the Chik virus during silent period, the presence of Ascogregarina has gained importance in recent days. The prevalence was found to be 71.62. PMID:22471176

  2. Population genetics with RAPD-PCR markers: the breeding structure of Aedes aegypti in Puerto Rico.

    PubMed

    Apostol, B L; Black, W C; Reiter, P; Miller, B R

    1996-04-01

    RAPD-PCR polymorphisms at 57 presumptive loci were used to examine the breeding structure of the mosquito Aedes aegypti in Puerto Rico. Mosquitoes were sampled from 16 locations in six cities and samples were located in a nested spatial design to examine local patterns of gene flow. Allele frequencies were estimated assuming (1) that genomic regions amplified by RAPD-PCR segregate as dominant alleles, (2) that genotypes at RAPD loci are in Hardy-Weinberg proportions, (3) identity in state (iis) among dominant amplified alleles and (4) iis among null alleles. The average genic heterozygosity was 0.354, more than twice the level detected in earlier allozyme surveys. Nested analysis of variance indicated extensive genetic differentiation among locations within cities. Effective migration rates (Nm) among cities were estimated from FST assuming an island model of migration. Estimates of Nm ranged from 9.7 to 12.2 indicating a high dispersal rate. The large number of polymorphisms revealed by RAPD-PCR allowed the distribution of FST and linkage disequilibrium to be examined among loci and demonstrated that small samples inflate FST and linkage disequilibrium. No linkage disequilibrium maintained through epistasis was detected among alleles at the 57 loci. PMID:8626220

  3. Modelling the breeding of Aedes Albopictus species in an urban area in Pulau Pinang using polynomial regression

    NASA Astrophysics Data System (ADS)

    Salleh, Nur Hanim Mohd; Ali, Zalila; Noor, Norlida Mohd.; Baharum, Adam; Saad, Ahmad Ramli; Sulaiman, Husna Mahirah; Ahmad, Wan Muhamad Amir W.

    2014-07-01

    Polynomial regression is used to model a curvilinear relationship between a response variable and one or more predictor variables. It is a form of a least squares linear regression model that predicts a single response variable by decomposing the predictor variables into an nth order polynomial. In a curvilinear relationship, each curve has a number of extreme points equal to the highest order term in the polynomial. A quadratic model will have either a single maximum or minimum, whereas a cubic model has both a relative maximum and a minimum. This study used quadratic modeling techniques to analyze the effects of environmental factors: temperature, relative humidity, and rainfall distribution on the breeding of Aedes albopictus, a type of Aedes mosquito. Data were collected at an urban area in south-west Penang from September 2010 until January 2011. The results indicated that the breeding of Aedes albopictus in the urban area is influenced by all three environmental characteristics. The number of mosquito eggs is estimated to reach a maximum value at a medium temperature, a medium relative humidity and a high rainfall distribution.

  4. Relative abundance of tree hole-breeding mosquitoes in Boone County, Missouri, USA, with emphasis on the vector potential of Aedes triseriatus for canine heartworm, Dirofilaria immitis (Spirurida: Filariidae).

    PubMed

    Debboun, Mustapha; Green, Theodore J; Rueda, Leopoldo M; Hall, Robert D

    2005-09-01

    Aedes (Protomacleaya) triseriatus currently shares its habitat in the USA with the introduced species Aedes (Finlaya) japonicus and Aedes (Stegomyia) albopictus. In the late 1980s, before the introduction of these 2 species, Ae. triseriatus was the dominant tree hole- and artificial container-breeding mosquito in central Missouri. Aedes triseriatus represented 89% of the mosquito immatures collected from water-filled tree holes and artificial containers at 3 forested field sites in central Missouri, from May to October, 1986 to 1988. Laboratory-reared female Ae. triseriatus were able to support larval development of Dirofilaria immitis (canine heartworm) to the infective 3rd larval stage. A blood meal from a microfilaremic Collie-mix dog was sufficient to infect adult female mosquitoes, indicating that Ae. triseriatus is a possible vector of canine heartworm in central Missouri. Confirmation of the vector status of this species depends on the yet-to-be observed transmission of D. immitis by Ae. triseriatus in the field, possibly by experimental infection of dogs by wild-caught mosquitoes. Defining the role of this species in epizootic outbreaks could contribute toward accurate risk assessment as the abundance of Ae. triseriatus increases and decreases in response to the success of Ae. albopictus, Ae. japonicus, or other introduced container-breeding mosquitoes. PMID:16252517

  5. Spatial distribution & physicochemical characterization of the breeding habitats of Aedes aegypti in & around Kolkata, West Bengal, India

    PubMed Central

    Chatterjee, Soumendranath; Chakraborty, Arunima; Sinha, Shuvra Kanti

    2015-01-01

    Background & objectives: Dengue infection is endemic in several areas and the dengue virus is transmitted by Aedes mosquitoes. Thus, it becomes important to understand the breeding ecology of dengue vector and characterize the physicochemical parameters of its breeding habitat. The objective of this study was to analyze the physicochemical parameters of the breeding habitat of the dengue vector and to find out the nutrient composition of the habitat in and around Kolkata, West Bengal. In addition, a geographic information system (GIS) was used to map the disease prone areas for its effective management and prevention. Methods: Water samples were collected from various breeding habitats of Aedes mosquitoes of Kolkata and adjoining areas and were analysed for various physicochemical properties like acidity, alkalinity, hardness, electrical conductivity, total dissolved solids, concentration of chloride (Cl-), sodium (Na+), potassium (K+), fluoride (F-) in relation to larval prevalence. Results: Parameters like water pH, total dissolved solids, total hardness, electrical conductivity, concentration of chloride, sodium and potassium were seen to vary throughout the year. Certain parameters were found to be dependent on container type, like concentration of fluoride. Significant positive correlations were seen between per dip larval density and total dissolved solids (TDS) and electrical conductivity. Interpretation & conclusions: Water pH, electrical conductivity, total dissolved solids were seen to play a major role in the ovipositional preferences. Container type did not seem to affect TDS. Tyres had the highest TDS in most of the cases. Nutrient composition like sodium concentration was mostly found in the coconut shells, potassium concentration also showed the same. Thus, container type and various parameters and nutrients play a major role in determining where a gravid female mosquito will lay its eggs. It was observed that by altering various chemical and

  6. Breeding places and seasonal incidence of Aedes aegypti, as assessed by the single-larva survey method*

    PubMed Central

    Rao, T. Ramachandra; Trpis, M.; Gillett, J. D.; Teesdale, C.; Tonn, R. J.

    1973-01-01

    The single-larva survey method was employed to study the breeding places and seasonal incidence of Aedes aegypti in Dar es Salaam, Tanzania. From May 1968 to May 1969, 28 462 containers of water—located in approximately equal numbers indoors and outdoors—were investigated. The highest frequency of breeding (8.0%) of A. aegypti was observed in tires and motor parts. Drums, barrels, water-pots, and other receptacles left outdoors showed a higher frequency (3.1%) than those kept indoors (0.6%). Metal containers were infested to a greater extent than those made of mud, wood, or other materials; 2.5% of coconut shells, snail shells, etc. and 1.3% of tree holes, plant axils, and cut bamboos were infested. The seasonal prevalence, expressed as a container index, closely followed and paralleled the fluctuations in rainfall. The value of this survey method for both ecological studies and practical control purposes is discussed. PMID:4544149

  7. Southwestern Willow Flycatcher Breeding Site and Territory Summary - 2006

    USGS Publications Warehouse

    Durst, Scott L.; Sogge, Mark K.; Stump, Shay D.; Williams, Sartor O.; Kus, Barbara E.; Sferra, Susan J.

    2007-01-01

    Introduction The Southwestern Willow Flycatcher (Empidonax traillii extimus) is an endangered bird that breeds only in dense riparian habitats in six southwestern states (southern California, extreme southern Nevada, southern Utah, southwestern Colorado, Arizona, and New Mexico). Since 1993, hundreds of Southwestern Willow Flycatcher surveys have been conducted each year, and many new flycatcher breeding sites located. This document synthesizes information on all known Southwestern Willow Flycatcher breeding sites. This rangewide data synthesis was designed to meet these objectives: * identify all known Southwestern Willow Flycatcher breeding sites, and * assemble data on population size, location, habitat, and other information for all breeding sites, for as many years as possible, from 1993 through 2006. This report provides data summaries in terms of the number of flycatcher sites and the number of territories.

  8. Indoor-Breeding of Aedes albopictus in Northern Peninsular Malaysia and Its Potential Epidemiological Implications

    PubMed Central

    Dieng, Hamady; Saifur, Rahman G. M.; Hassan, Ahmad Abu; Salmah, M. R. Che; Boots, Michael; Satho, Tomomitsu; Jaal, Zairi; AbuBakar, Sazaly

    2010-01-01

    Background The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity due to the potential increase in blood feeding opportunities. Methodology/Principal Findings In a series of experiments involving outdoors and indoors breeding populations, we found that Ae. albopictus lives longer in the indoor environment. We also observed increased nighttime biting activity and lifetime fecundity in indoor/domestic adapted females, although they were similar to recently colonized females in body size. Conclusion/Significance Taken together these data suggest that accommodation of Ae. albopictus to indoor/domestic environment may increase its lifespan, blood feeding success, nuisance and thus vectorial capacity (both in terms of increased vector-host contacts and vector population density). These changes in the breeding behavior of Ae. albopictus, a potential vector of several human pathogens including dengue viruses, require special attention. PMID:20668543

  9. Site-specific cassette exchange systems in the Aedes aegypti mosquito and the Plutella xylostella moth.

    PubMed

    Haghighat-Khah, Roya Elaine; Scaife, Sarah; Martins, Sara; St John, Oliver; Matzen, Kelly Jean; Morrison, Neil; Alphey, Luke

    2015-01-01

    Genetically engineered insects are being evaluated as potential tools to decrease the economic and public health burden of mosquitoes and agricultural pest insects. Here we describe a new tool for the reliable and targeted genome manipulation of pest insects for research and field release using recombinase mediated cassette exchange (RMCE) mechanisms. We successfully demonstrated the established ΦC31-RMCE method in the yellow fever mosquito, Aedes aegypti, which is the first report of RMCE in mosquitoes. A new variant of this RMCE system, called iRMCE, combines the ΦC31-att integration system and Cre or FLP-mediated excision to remove extraneous sequences introduced as part of the site-specific integration process. Complete iRMCE was achieved in two important insect pests, Aedes aegypti and the diamondback moth, Plutella xylostella, demonstrating the transferability of the system across a wide phylogenetic range of insect pests. PMID:25830287

  10. Site-Specific Cassette Exchange Systems in the Aedes aegypti Mosquito and the Plutella xylostella Moth

    PubMed Central

    Haghighat-Khah, Roya Elaine; Scaife, Sarah; Martins, Sara; St John, Oliver; Matzen, Kelly Jean; Morrison, Neil; Alphey, Luke

    2015-01-01

    Genetically engineered insects are being evaluated as potential tools to decrease the economic and public health burden of mosquitoes and agricultural pest insects. Here we describe a new tool for the reliable and targeted genome manipulation of pest insects for research and field release using recombinase mediated cassette exchange (RMCE) mechanisms. We successfully demonstrated the established ΦC31-RMCE method in the yellow fever mosquito, Aedes aegypti, which is the first report of RMCE in mosquitoes. A new variant of this RMCE system, called iRMCE, combines the ΦC31-att integration system and Cre or FLP-mediated excision to remove extraneous sequences introduced as part of the site-specific integration process. Complete iRMCE was achieved in two important insect pests, Aedes aegypti and the diamondback moth, Plutella xylostella, demonstrating the transferability of the system across a wide phylogenetic range of insect pests. PMID:25830287

  11. Chromosomal fragile site expression in dogs: I. Breed specific differences.

    PubMed

    Stone, D M; Jacky, P B; Hancock, D D; Prieur, D J

    1991-08-01

    Peripheral blood lymphocytes from clinically normal Doberman pinscher and boxer dogs were cultured for folate-sensitive and, in preliminary studies, aphidicolin-inducible fragile site expression. Both autosomal and X chromosomal fragile sites were observed in canine cells cultured under folate/thymidine depletion and in cells cultured in medium containing aphidicolin. Results from the three dogs evaluated for both folate-sensitive and aphidicolin-inducible fragile site expression showed that the frequency of fragile site expression was significantly (P less than 0.05) greater in cells cultured in medium containing aphidicolin than in cells cultured in folate/thymidine-depleted medium. Cells from the boxer dog expressed a high percentage (66.67%) of aphidicolin-inducible fragile sites in contrast to the Doberman pinscher dog in which only 21.10% of the lymphocytes expressed aphidicolin-inducible fragile sites. The frequencies of spontaneous and folate-sensitive fragile site expression did not vary significantly by breed of dog. Age of dog was significantly and positively correlated with frequency of folate-sensitive fragile site expression in dogs of the boxer breed, but not in dogs of the Doberman pinscher breed. The dog X chromosome expressed three folate-sensitive and aphidicolin-inducible fragile sites. The G-band location of these three fragile sites showed homology with three recognized constitutive common fragile sites on the human X chromosome: Xp22, Xq21, and Xq27.2. Two specific autosomal fragile sites were identified, one on the distal end of the long arm of chromosome 1 and one on the distal end of the long arm of chromosome 8. Other autosomal fragile sites were also apparent but could not be assigned reliably to specific chromosomes. PMID:1910263

  12. Household survey of container-breeding mosquitoes and climatic factors influencing the prevalence of Aedes aegypti (Diptera: Culicidae) in Makkah City, Saudi Arabia

    PubMed Central

    Aziz, Al Thabiany; Dieng, Hamady; Ahmad, Abu Hassan; Mahyoub, Jazem A; Turkistani, Abdulhafis M; Mesed, Hatabbi; Koshike, Salah; Satho, Tomomitsu; Salmah, MR Che; Ahmad, Hamdan; Zuharah, Wan Fatma; Ramli, Ahmad Saad; Miake, Fumio

    2012-01-01

    Objective To investigate the prevalence of container breeding mosquitoes with emphasis on the seasonality and larval habitats of Aedes aegypti (Ae. aegypti) in Makkah City, adjoining an environmental monitoring and dengue incidence. Methods Monthly visits were performed between April 2008 and March 2009 to randomly selected houses. During each visit, mosquito larvae were collected from indoors and outdoors containers by either dipping or pipetting. Mosquitoes were morphologically identified. Data on temperature, relative humidity, rain/precipitations during the survey period was retrieved from governmental sources and analyzed. Results The city was warmer in dry season (DS) than wet season (WS). No rain occurred at all during DS and even precipitations did fall, wetting events were much greater during WS. Larval survey revealed the co-breeding of Aedes, Culex and Anopheles in a variety of artificial containers in and around homes. 32 109 larvae representing 1st , 2nd, 3rd, and 4th stages were collected from 22 618 container habitats. Culicines was far the commonest and Aedes genus was as numerous as the Culex population. Ae. aegypti larval abundance exhibited marked temporal variations, overall, being usually more abundant during WS. Ten types of artificial containers were found with developing larvae. 70% of these habitats were located indoors. 71.42% of indoor containers were permanent and 28.58% was semi-permanent during WS. Cement tanks was the only container type permanent during DS. Ae. aegypti larval indices (CI, HI, BI) recorded were greater during WS. Conclusions Taken together, these results indicate a high risk of dengue transmission in the holy city. PMID:23569860

  13. Rock coasts and seabird breeding sites : a common optimization

    NASA Astrophysics Data System (ADS)

    Marie, Eveillard-Buchoux

    2014-05-01

    The North-West coasts of Europe support a lot of part of Northern hemisphere breeding seabirds. In that context, Scotland has a preponderant place and Brittany has southernmost limit of these species areas, for most of them. Outside the breeding season these species live mainly on the open sea and when they do visit the land to breed, they nest on a specific sites : almost all the time they breed on the rock coasts, often on seacliffs. This specific habitat are defines by geomorphological characteristics which offer special forms of the coast. The forms of rock coasts are originally and different because of several proprieties of geology, of lithology, of structures. Breeding seabird, occupying these sites, reveals, in a new light, the richness of these forms and the originals geographic location of the coastline : seabirds prefer nest in exposed coastline like rock caps, rocky points or islands. Seabirds and rock coasts are research topics in environmental geography since several years. However, these combination studies is a new approach in this field and enlargement in the heritage field allows supplement scientific approach. For example, it show that in most important touristic sites, environmental protection measures focused on landscape, habitat or bird, but much more rarely on rock coasts for these intrinsic values. Indeed, in Brittany or in Scotland, seabirds are often stars species in lot of coastal nature reserves, where they're considered like greater ecological heritage. We could see it in touristic promotion field : bird is everywhere, cliff is mostly kept in the dark, as well in leaflets as in speech visitor's guides - without, for example, as a part of this landscape. In all cases, combination of these two heritages is extremely rare. Yet, this current research illustrates the interest and the issue of development of this comparative approach seabirds / rock coasts for optimization of nature tourism and geotourism.

  14. Spatial and temporal dynamics of Aedes aegypti larval sites in Bello, Colombia.

    PubMed

    Arboleda, Sair; Jaramillo-O, Nicolás; Peterson, A Townsend

    2012-06-01

    Counts of immature stages of the mosquito Aedes aegypti have been used to calculate several entomological indices of dengue vector abundance. Some studies have concluded that these indices can be used as indicators of dengue epidemic risk, while other studies have failed to find a predictive relationship. Ecological niche models have been able to predict distributional patterns in space and time, not only of vectors, but also of the diseases that they transmit. In this study, we used Landsat 7 ETM+ images and two niche-modeling algorithms to estimate the local-landscape ecological niche and the dynamics of Ae. aegypti larval habitats in Bello, Colombia, and to evaluate their potential spatial and temporal distribution. Our models showed low omission error with high confidence levels: about 13.4% of the area presents conditions consistently suitable for breeding across the entire study period (2002-2008). The proportion of neighborhoods predicted to be suitable showed a positive association with dengue case rates, whereas the vector-focused Bretau index had no relationship to case rates. As a consequence, niche models appear to offer a superior option for predictive evaluation of dengue transmission risk and anticipating the potential for outbreaks. PMID:22548535

  15. Seasonal abundance of Aedes albopictus in selected urban and suburban areas in Penang, Malaysia.

    PubMed

    Rozilawati, H; Zairi, J; Adanan, C R

    2007-06-01

    Ovitrap surveillance was conducted in a selected urban area and suburban area, ie. Taman Permai Indah(TPI) and Kampung Pasir Gebu (KPG) in Penang for 14 months. It was found that Aedes albopictus was the most abundant Aedes species in both study areas, even though a small percentage of Aedes aegypti and Culex quinquefasciatus were found to breed simultaneously in the same ovitrap. This study indicated that the main dengue vector was Ae. albopictus. A strong correlation was found between rainfall and egg population in both of the study sites (r = 0.982 and r = 0.918). PMID:17568381

  16. Natural vertical transmission of dengue viruses in Aedes aegypti in selected sites in Cebu City, Philippines.

    PubMed

    Edillo, Frances E; Sarcos, Janet R; Sayson, Stephanie L

    2015-12-01

    We attempted to determine the vertical transmission of dengue virus (DENV) in Aedes aegypti in selected sites in Cebu City, Philippines. Mosquito sub-adults were collected monthly from households and the field during the wet-dry-wet season from November, 2011 to July, 2012 and were laboratory-reared to adults. Viral RNA extracts in mosquitoes were assayed by hemi-nested RT-PCR. Results showed that 62 (36.26%; n=679) out of 171 mosquito pools (n=2,871) were DENV+. The minimum infection rate (MIR) of DENV ranged from 0 in wet months to 48.22/1,000 mosquitoes in April, 2012 (mid-dry). DENVs were detected in larvae, pupae, and male and female adults, with DENV-4, DENV-3, and DENV-1, in that rank of prevalence. DENV-1 co-infected with either DENV-3 or -4 or with both in April, 2012; DENV-3 and -4 were present in both seasons. More DENV+ mosquitoes were collected from households than in field premises (p<0.001) and in the dry than in the wet season (p<0.05), with significant interaction (p<0.05) between sites and premises but no interaction between sites and seasons (p>0.05). By Generalized Linear Mixed models, the type of premises nested in sites and monthly total rainfall were significant predictors of monthly dengue cases (p<0.05) and not MIR, season, temperature, and relative humidity. Surveillance of DENV prevalence in Ae. aegypti and detecting their natural foci in the dry season provide an early warning signal of dengue outbreak. PMID:26611963

  17. Seasonal Genetic Changes of Aedes aegypti (Diptera: Culicidae) Populations in Selected Sites of Cebu City, Philippines

    PubMed Central

    Sayson, S. L.; Gloria-Soria, A.; Powell, J. R.; Edillo, F. E.

    2015-01-01

    Aedes aegypti (L.) is the primary vector of dengue virus in the Philippines, where dengue is endemic. We examined the genetic changes of Ae. aegypti collected from three selected sites in Cebu city, Philippines, during the relatively wet (2011–2012) and dry seasons (2012 and 2013). A total of 493 Ae. aegypti adults, reared in the laboratory from field-collected larvae, were analyzed using 11 microsatellite loci. Seasonal variation was observed in allele frequencies and allelic richness. Average genetic differentiation (DEST = 0.018; FST = 0.029) in both dry seasons was higher, due to reduced Ne, than in the wet season (DEST=0.006; FST=0.009). Thus, average gene flow was higher in the wet season than in the dry seasons. However, the overall FST estimate (0.02) inclusive of the two seasons showed little genetic differentiation as supported by Bayesian clustering analysis. Results suggest that during the dry season the intense selection that causes a dramatic reduction of population size favors heterozygotes, leading to small pockets of mosquitoes (refuges) that exhibit random genetic differentiation. During the wet season, the genetic composition of the population is reconstituted by the expansion of the refuges that survived the preceding dry season. Source reduction of mosquitoes during the nonepidemic dry season is thus recommended to prevent dengue re-emergence in the subsequent wet season. PMID:26335470

  18. Seasonal Genetic Changes of Aedes aegypti (Diptera: Culicidae) Populations in Selected Sites of Cebu City, Philippines.

    PubMed

    Sayson, S L; Gloria-Soria, A; Powell, J R; Edillo, F E

    2015-07-01

    Aedes aegypti (L.) is the primary vector of dengue virus in the Philippines, where dengue is endemic. We examined the genetic changes of Ae. aegypti collected from three selected sites in Cebu city, Philippines, during the relatively wet (2011-2012) and dry seasons (2012 and 2013). A total of 493 Ae. aegypti adults, reared in the laboratory from field-collected larvae, were analyzed using 11 microsatellite loci. Seasonal variation was observed in allele frequencies and allelic richness. Average genetic differentiation (DEST=0.018; FST=0.029) in both dry seasons was higher, due to reduced Ne, than in the wet season (DEST=0.006; FST=0.009). Thus, average gene flow was higher in the wet season than in the dry seasons. However, the overall FST estimate (0.02) inclusive of the two seasons showed little genetic differentiation as supported by Bayesian clustering analysis. Results suggest that during the dry season the intense selection that causes a dramatic reduction of population size favors heterozygotes, leading to small pockets of mosquitoes (refuges) that exhibit random genetic differentiation. During the wet season, the genetic composition of the population is reconstituted by the expansion of the refuges that survived the preceding dry season. Source reduction of mosquitoes during the nonepidemic dry season is thus recommended to prevent dengue re-emergence in the subsequent wet season. PMID:26335470

  19. Kin-bias, breeding site selection and female fitness in a cannibalistic Neotropical frog.

    PubMed

    Muralidhar, P; de Sá, F P; Haddad, C F B; Zamudio, K R

    2014-02-01

    Resource availability influences sexual selection within populations and determines whether behaviours such as territoriality or resource sharing are adaptive. In Thoropa taophora, a frog endemic to the Atlantic Coastal Rainforest of Brazil, males compete for and defend limited breeding sites while females often share breeding sites with other females; however, sharing breeding sites may involve costs due to cannibalism by conspecific tadpoles. We studied a breeding population of T. taophora to determine (i) whether this species exhibits polygynous mating involving female choice for territorial males and limited breeding resources; (ii) whether limited breeding resources create the potential for male-male cooperation in defence of neighbouring territories; and (iii) whether females sharing breeding sites exhibit kin-biased breeding site choice, possibly driven by fitness losses due to cannibalism among offspring of females sharing sites. We used microsatellites to reconstruct parentage and quantify relatedness at eight breeding sites in our focal population, where these sites are scarce, and in a second population, where sites are abundant. We found that at localities where the appropriate sites for reproduction are spatially limited, the mating system for this species is polygynous, with typically two females sharing a breeding site with a male. We also found that females exhibit negative kin-bias in their choice of breeding sites, potentially to maximize their inclusive fitness by avoiding tadpole cannibalism of highly related kin. Our results indicate that male territorial defence and female site sharing are likely important components of this mating system, and we propose that kinship-dependent avoidance in mating strategies may be more general than previously realized. PMID:24237705

  20. Highly focused anopheline breeding sites and malaria transmission in Dakar

    PubMed Central

    Machault, Vanessa; Gadiaga, Libasse; Vignolles, Cécile; Jarjaval, Fanny; Bouzid, Samia; Sokhna, Cheikh; Lacaux, Jean-Pierre; Trape, Jean-François; Rogier, Christophe; Pagès, Frédéric

    2009-01-01

    Background Urbanization has a great impact on the composition of the vector system and malaria transmission dynamics. In Dakar, some malaria cases are autochthonous but parasite rates and incidences of clinical malaria attacks have been recorded at low levels. Ecological heterogeneity of malaria transmission was investigated in Dakar, in order to characterize the Anopheles breeding sites in the city and to study the dynamics of larval density and adult aggressiveness in ten characteristically different urban areas. Methods Ten study areas were sampled in Dakar and Pikine. Mosquitoes were collected by human landing collection during four nights in each area (120 person-nights). The Plasmodium falciparum circumsporozoite (CSP) index was measured by ELISA and the entomological inoculation rates (EIR) were calculated. Open water collections in the study areas were monitored weekly for physico-chemical characterization and the presence of anopheline larvae. Adult mosquitoes and hatched larvae were identified morphologically and by molecular methods. Results In September-October 2007, 19,451 adult mosquitoes were caught among which, 1,101 were Anopheles gambiae s.l. The Human Biting Rate ranged from 0.1 bites per person per night in Yoff Village to 43.7 in Almadies. Seven out of 1,101 An. gambiae s.l. were found to be positive for P. falciparum (CSP index = 0.64%). EIR ranged from 0 infected bites per person per year in Yoff Village to 16.8 in Almadies. The An. gambiae complex population was composed of Anopheles arabiensis (94.8%) and Anopheles melas (5.2%). None of the An. melas were infected with P. falciparum. Of the 54 water collection sites monitored, 33 (61.1%) served as anopheline breeding sites on at least one observation. No An. melas was identified among the larval samples. Some physico-chemical characteristics of water bodies were associated with the presence/absence of anopheline larvae and with larval density. A very close parallel between larval and adult

  1. Mosquito-Disseminated Pyriproxyfen Yields High Breeding-Site Coverage and Boosts Juvenile Mosquito Mortality at the Neighborhood Scale

    PubMed Central

    Abad-Franch, Fernando; Zamora-Perea, Elvira; Ferraz, Gonçalo; Padilla-Torres, Samael D.; Luz, Sérgio L. B.

    2015-01-01

    Background Mosquito-borne pathogens pose major public health challenges worldwide. With vaccines or effective drugs still unavailable for most such pathogens, disease prevention heavily relies on vector control. To date, however, mosquito control has proven difficult, with low breeding-site coverage during control campaigns identified as a major drawback. A novel tactic exploits the egg-laying behavior of mosquitoes to have them disseminate tiny particles of a potent larvicide, pyriproxyfen (PPF), from resting to breeding sites, thus improving coverage. This approach has yielded promising results at small spatial scales, but its wider applicability remains unclear. Methodology/Principal Findings We conducted a four-month trial within a 20-month study to investigate mosquito-driven dissemination of PPF dust-particles from 100 ‘dissemination stations’ (DSs) deployed in a 7-ha sub-area to surveillance dwellings and sentinel breeding sites (SBSs) distributed over an urban neighborhood of about 50 ha. We assessed the impact of the trial by measuring juvenile mosquito mortality and adult mosquito emergence in each SBS-month. Using data from 1,075 dwelling-months, 2,988 SBS-months, and 29,922 individual mosquitoes, we show that mosquito-disseminated PPF yielded high coverage of dwellings (up to 100%) and SBSs (up to 94.3%). Juvenile mosquito mortality in SBSs (about 4% at baseline) increased by over one order of magnitude during PPF dissemination (about 75%). This led to a >10-fold decrease of adult mosquito emergence from SBSs, from approximately 1,000–3,000 adults/month before to about 100 adults/month during PPF dissemination. Conclusions/Significance By expanding breeding-site coverage and boosting juvenile mosquito mortality, a strategy based on mosquito-disseminated PPF has potential to substantially enhance mosquito control. Sharp declines in adult mosquito emergence can lower vector/host ratios, reducing the risk of disease outbreaks. This approach is a very

  2. Evidence for wing molt and breeding site fidelity in King Eiders

    USGS Publications Warehouse

    Phillips, Laura M.; Powell, A.N.

    2006-01-01

    Fidelity of King Eiders (Somateria spectabilis) to breeding and wing molt sites was examined using satellite telemetry data obtained opportunistically when battery life of transmitters provided locations in a second year. Consecutive breeding locations were obtained for eleven female and 23 male King Eiders. All females exhibited breeding site fidelity by returning to sites within 15 km of first year breeding areas on the North Slope of Alaska. Breeding locations of males in a subsequent year were located on average >1000 km from their prior breeding sites and were primarily outside Alaska, on the coasts of Russia and Canada. Second-year wing molt locations were obtained for two female and six male King Eiders. Wing molt sites of males were located 6.2 ?? 3.1 km apart on average in successive years, while female wing molt locations averaged almost 50 km apart. Our results demonstrate site fidelity of female King Eiders to a breeding area on the North Slope of Alaska, document the dispersal of male King Eiders between breeding seasons, and present the first evidence for wing molt site fidelity in males.

  3. Lectin-binding sites on ejaculated stallion sperm during breeding and non-breeding periods.

    PubMed

    Desantis, S; Ventriglia, G; Zizza, S; Nicassio, M; Valentini, L; Di Summa, A; Lacalandra, G M

    2010-05-01

    Stallion sperm from semen collected in Southern Italy during the breeding (June-July) and non-breeding (December-January) periods were analyzed by means of twelve lectins to evaluate the glycoconjugate pattern and to verify whether there are any seasonal differences in the glycosylation pattern of the sperm glycocalyx. The acrosomal cap showed reactivity for Maackia amurensis (MAL II), Sambucus nigra (SNA), Arachis hypogaea (PNA), Glycine max (SBA), Helix pomatia (HPA), Canavalia ensiformis (Con A) Triticum vulgaris (WGA), and Griffonia simplicifolia isolectin II (GSA II) in breeding and non-breeding ejaculated sperm, suggesting the presence of oligosaccharides terminating with Neu5Ac alpha 2,3Gal beta 1,4GlcNAc, Neu5Ac alpha 2,6Gal/GalNAc, with Gal beta 1,3GalNAc, alpha/beta GalNAc and glycans with terminal/internal alpha Man and GlcNAc. During the non-breeding period, the acrosomal cap expressed oligosaccharides terminating with Gal beta 1,4GlcNAc (Ricinus communis(120) affinity) (RCA(120)) and L-Fuc alpha 1,2Gal beta 1,4GlcNAc beta (Ulex europaeus affinity) (UEA I). The equatorial segment placed between the acrosomal cap and post-acrosomal region did not display glycans terminating with GalNAc, GlcNAc, and alpha L-Fuc. The post-acrosomal region of sperm collected in the breeding and non-breeding periods bound Con A, MAL II, SNA, and SBA, thus showing the presence of N-linked oligosaccharides from high-Man content, terminating with Neu5Ac alpha 2,3Gal beta 1,4GlcNAc, Neu5Ac alpha 2,6Gal/GalNAc and GalNAc. In winter, the post-acrosomal region also expressed oligosaccharides terminating with alpha GalNAc, GlcNAc, and L-Fuc alpha 1,2Gal beta 1,4GlcNAc beta (HPA, GSA II, and UEA I staining). The tail of sperm from semen collected during the breeding and non-breeding periods showed a lectin binding pattern similar to the post-acrosomal region, except for the absence of HPA staining in sperm collected during the winter season. These results indicate that the surface of

  4. Mercury in Nelson's Sparrow Subspecies at Breeding Sites

    PubMed Central

    Winder, Virginia L.; Emslie, Steven D.

    2012-01-01

    Background Mercury is a persistent, biomagnifying contaminant that can cause negative effects on ecosystems. Marshes are often areas of relatively high mercury methylation and bioaccumulation. Nelson's Sparrows (Ammodramus nelsoni) use marsh habitats year-round and have been documented to exhibit tissue mercury concentrations that exceed negative effects thresholds. We sought to further characterize the potential risk of Nelson's Sparrows to mercury exposure by sampling individuals from sites within the range of each of its subspecies. Methodology/Principal Findings From 2009 to 2011, we captured adult Nelson's Sparrows at sites within the breeding range of each subspecies (A. n. nelsoni: Grand Forks and Upham, North Dakota; A. n. alterus: Moosonee, Ontario; and A. n. subvirgatus: Grand Manan Island, New Brunswick) and sampled breast feathers, the first primary feather (P1), and blood for total mercury analysis. Mean blood mercury in nelsoni individuals captured near Grand Forks ranged from 0.84±0.37 to 1.65±1.02 SD ppm among years, between 2.0 and 4.9 times as high as concentrations at the other sites (P<0.01). Breast feather mercury did not vary among sites within a given sampling year (site means ranged from 0.98±0.69 to 2.71±2.93 ppm). Mean P1 mercury in alterus (2.96±1.84 ppm fw) was significantly lower than in any other sampled population (5.25±2.24–6.77±3.51 ppm; P≤0.03). Conclusions/Significance Our study further characterized mercury in Nelson's Sparrows near Grand Forks; we documented localized and potentially harmful mercury concentrations, indicating that this area may represent a biological mercury hotspot. This finding warrants further research to determine if wildlife populations of conservation or recreational interest in this area may be experiencing negative effects due to mercury exposure. We present preliminary conclusions about the risk of each sampled population to mercury exposure. PMID:22384194

  5. Dengue vector management using insecticide treated materials and targeted interventions on productive breeding-sites in Guatemala

    PubMed Central

    2012-01-01

    Background In view of the epidemiological expansion of dengue worldwide and the availability of new tools and strategies particularly for controlling the primary dengue vector Aedes aegypti, an intervention study was set up to test the efficacy, cost and feasibility of a combined approach of insecticide treated materials (ITMs) alone and in combination with appropriate targeted interventions of the most productive vector breeding-sites. Methods The study was conducted as a cluster randomized community trial using “reduction of the vector population” as the main outcome variable. The trial had two arms: 10 intervention clusters (neighborhoods) and 10 control clusters in the town of Poptun Guatemala. Activities included entomological assessments (characteristics of breeding-sites, pupal productivity, Stegomyia indices) at baseline, 6 weeks after the first intervention (coverage of window and exterior doorways made of PermaNet 2.0 netting, factory treated with deltamethrin at 55 mg/m2, and of 200 L drums with similar treated material) and 6 weeks after the second intervention (combination of treated materials and other suitable interventions targeting productive breeding-sites i.e larviciding with Temephos, elimination etc.). The second intervention took place 17 months after the first intervention. The insecticide residual activity and the insecticidal content were also studied at different intervals. Additionally, information about demographic characteristics, cost of the intervention, coverage of houses protected and satisfaction in the population with the interventions was collected. Results At baseline (during the dry season) a variety of productive container types for Aedes pupae were identified: various container types holding >20 L, 200 L drums, washbasins and buckets (producing 83.7% of all pupae). After covering 100% of windows and exterior doorways and a small number of drums (where the commercial cover could be fixed) in 970 study households, tropical

  6. Application of remotely sensed multispectral data to automated analysis of marshland vegetation. Inference to the location of breeding habitats of the salt marsh mosquito (Aedes Sollicitans)

    NASA Technical Reports Server (NTRS)

    Cibula, W. G.

    1976-01-01

    The techniques used for the automated classification of marshland vegetation and for the color-coded display of remotely acquired data to facilitate the control of mosquito breeding are presented. A multispectral scanner system and its mode of operation are described, and the computer processing techniques are discussed. The procedures for the selection of calibration sites are explained. Three methods for displaying color-coded classification data are presented.

  7. Mapping urban and peri-urban breeding habitats of Aedes mosquitoes using a fuzzy analytical hierarchical process based on climatic and physical parameters.

    PubMed

    Sarfraz, Muhammad Shahzad; Tripathi, Nagesh K; Faruque, Fazlay S; Bajwa, Usama Ijaz; Kitamoto, Asanobu; Souris, Marc

    2014-01-01

    The spread of dengue fever depends mainly on the availability of favourable breeding sites for its mosquito vectors around human dwellings. To investigate if the various factors influencing breeding habitats can be mapped from space, dengue indices, such as the container index, the house index and the Breteau index, were calculated from Ministry of Public health data collected three times annually in Phitsanulok, Thailand between 2009 and 2011. The most influential factors were found to be temperature, humidity, rainfall, population density, elevation and land cover. Models were worked out using parameters mostly derived from freely available satellite images and fuzzy logic software with parameter synchronisation and a predication algorithm based on data mining and the Decision Tree method. The models developed were found to be sufficiently flexible to accommodate additional parameters and sampling data that might improve prediction of favourable breeding hotspots. The algorithm applied can not only be used for the prediction of near real-time scenarios with respect to dengue, but can also be applied for monitoring other diseases influenced by environmental and climatic factors. The multi-criteria model presented is a cost-effective way of identifying outbreak hotspots and early warning systems lend themselves for development based on this strategy. The proposed approach demonstrates the successful utilisation of remotely sensed images to map mosquito breeding habitats. PMID:25599639

  8. A review of brood-site pollination mutualism: plants providing breeding sites for their pollinators.

    PubMed

    Sakai, Shoko

    2002-06-01

    In this paper, I review pollination systems in which plants provide breeding sites as a reward for pollination. I divide the pollinators into three groups based upon ovipositing sites and the larval food of insects. The first group consists of ovule parasites found in only five plant lineages, e.g., the fig wasps and yucca moths, pollination systems in which pollinator specificity is very high. The second group is pollen parasitism, primarily by thrips (Thysanoptera), but specificity of the pollinators is low. In the third group, pollinator larvae (Coleoptera and Diptera) develop in decomposed flowers and inflorescences of plants and these adaptations evolved repeatedly via different pathways in various plant taxa. Pollinator specificity varies, and shifts in pollinators may occur between related or unrelated insects. PMID:12579365

  9. Individual fluctuations in toxin levels affect breeding site fidelity in a chemically defended amphibian.

    PubMed

    Bucciarelli, Gary M; Green, David B; Shaffer, H Bradley; Kats, Lee B

    2016-05-25

    Behaviours that influence habitat selection strongly determine species movement patterns. One component of animal behaviour that largely influences movement patterns and habitat choice is site fidelity. California newts (family Salamandridae) demonstrate remarkable site fidelity, typically homing to the same pool of a stream each breeding season. Individuals often occupy a specific pool throughout the breeding season, but some males shift among breeding pools, altering their set of potential mates, competitors, and predators. In this study, we measured dermal concentrations of the chemical defence compound tetrodotoxin (TTX) in recaptured male California newts (Taricha torosa) over five breeding seasons to evaluate whether relative TTX concentrations are associated with breeding site fidelity in the field. Our five years of field sampling indicates that TTX concentrations of individuals and group means fluctuate tremendously, implying that TTX is not a stable phenotypic trait. Despite such fluctuations, we found that an individual's relative TTX concentration explains fidelity to a breeding pool and suggests that newts may be able to assess both their own concentrations of TTX and that of conspecifics to make decisions about remaining in or abandoning a breeding pool. These results provide us a novel dimension to chemical defence phenotypes in nature and their ecological consequences, potentially requiring a re-evaluation of the coevolutionary dynamics of predation pressure on toxin-laden organisms. PMID:27194704

  10. Aedes aegypti (Diptera: Culicidae) production from non-residential sites in the Amazonian city of Iquitos, Peru.

    PubMed

    Morrison, A C; Sihuincha, M; Stancil, J D; Zamora, E; Astete, H; Olson, J G; Vidal-Ore, C; Scott, T W

    2006-04-01

    Programmes for the surveillance of Aedes aegypti (L.) often focus on residential areas, ignoring non-residential sites. Between November 2003 and October 2004, pupal/demographic surveys were therefore conducted in non-residential sites in the Peruvian city of Iquitos. The sampled sites included schools, factories, ports, public markets, petrol stations, commercial zones, airports, government buildings, animal-production areas, and recreational areas. Compared with the residential sites that had been surveyed a few years earlier, the non-residential sites generally had fewer pupae/ha, even though pupae were found in a high percentage of the sites investigated. Nonetheless, although <56 pupae/ha were observed in the industrial, commercial, recreational and school sites, the river boats in the ports and the areas in and around public markets sometimes had pupal abundances (of 122-213 pupae/ha) that were comparable with those previously recorded in the residential sites. When the relative production of Ae. aegypti was calculated by container type and characteristic (lidded/lidless, indoors/outdoors, and water-use patterns), no single container category was found to be a major producer of Ae. aegypti, with the exception of flower vases in cemeteries. In general, almost all (97%) of the pupae collected in the non-residential sites came from unlidded containers, although 91% of those collected in river boats came from lidded storage areas. With the exception of lumber mills, plant nurseries and markets (where only 39%-60% of the pupae were collected outdoors), >70% of pupal production was outdoors. In commercial areas, 41% of the pupae came from manually-filled containers, compared with <12% in residential sites. These results indicate that non-residential sites can be highly productive for Ae. aegypti and that the role of such sites in dengue transmission requires further investigation. PMID:16630393

  11. Breeding Season Demography and Movements of Eastern Towhees at the Savannah River Site, South Carolina

    SciTech Connect

    Krementz, D.G.; Powell, L.A.

    1999-09-22

    We studied eastern towhees at the Savannah River Site, a species of concern and in decline. Breeding season survival rates, nest success rates, breeding densities and daily movements were compared between mature longleaf savanna areas and recently harvested and regenerated areas. Survival rates did not vary by sex or stand type. Predation levels were very high. Abundances were lower in mature longleaf than recently regenerated areas.

  12. The Insecticide Susceptibility Status of Aedes aegypti (Diptera: Culicidae) in Farm and Nonfarm Sites of Lagos State, Nigeria.

    PubMed

    Ayorinde, A; Oboh, B; Oduola, A; Otubanjo, O

    2015-01-01

    Nigeria is one of the malaria-endemic countries. In Lagos State, Nigeria, various malaria vector control programs including the use of chemical insecticides are currently being implemented. This study was designed to provide information on the susceptibility status of some nontargeted vectors such as Aedes aegypti. Adult Ae. aegypti mosquitoes from two farm sites and a nonfarm site were exposed to World Health Organization test papers impregnated with Deltamethrin (0.05%), Permethrin (0.75%), and DDT (4%) insecticides. The Knockdown time (KdT50 and KdT95) and percentage mortality after 24 h post exposure were determined. In all the exposed mosquito populations to permethrin, mortality rate > 98% (susceptibility) was recorded, whereas mortality rates < 95.8% (resistance) and > 98% (susceptibility) to deltamethrin were observed in the nonfarm site and farm sites mosquito populations, respectively. All the mosquito populations were resistant to DDT in 2 yr. The KdT50 of the populations to DDT increased (60.2-69.6) in one of the farm sites and the nonfarm site (68.9-199.96), while a decrease (243-63.4) in another farm site in 2 yr. Significant difference (P < 0.05) in KdT50 was recorded between the farm and nonfarm sites Ae. aegypti mosquitoes in the second year after exposure to deltamethrin and DDT. An increase in KdT95 after exposure to deltamethrin in the first year was recorded. Higher KdT values and lower mortality rates in Ae. aegypti populations in the nonfarm sites are indications there are existing factors selecting for insecticide resistance outside agricultural use of insecticides. PMID:26106087

  13. The Insecticide Susceptibility Status of Aedes aegypti (Diptera: Culicidae) in Farm and Nonfarm Sites of Lagos State, Nigeria

    PubMed Central

    Ayorinde, A.; Oboh, B.; Oduola, A.; Otubanjo, O.

    2015-01-01

    Nigeria is one of the malaria-endemic countries. In Lagos State, Nigeria, various malaria vector control programs including the use of chemical insecticides are currently being implemented. This study was designed to provide information on the susceptibility status of some nontargeted vectors such as Aedes aegypti. Adult Ae. aegypti mosquitoes from two farm sites and a nonfarm site were exposed to World Health Organization test papers impregnated with Deltamethrin (0.05%), Permethrin (0.75%), and DDT (4%) insecticides. The Knockdown time (KdT50 and KdT95) and percentage mortality after 24 h post exposure were determined. In all the exposed mosquito populations to permethrin, mortality rate > 98% (susceptibility) was recorded, whereas mortality rates < 95.8% (resistance) and > 98% (susceptibility) to deltamethrin were observed in the nonfarm site and farm sites mosquito populations, respectively. All the mosquito populations were resistant to DDT in 2 yr. The KdT50 of the populations to DDT increased (60.2–69.6) in one of the farm sites and the nonfarm site (68.9–199.96), while a decrease (243–63.4) in another farm site in 2 yr. Significant difference (P < 0.05) in KdT50 was recorded between the farm and nonfarm sites Ae. aegypti mosquitoes in the second year after exposure to deltamethrin and DDT. An increase in KdT95 after exposure to deltamethrin in the first year was recorded. Higher KdT values and lower mortality rates in Ae. aegypti populations in the nonfarm sites are indications there are existing factors selecting for insecticide resistance outside agricultural use of insecticides. PMID:26106087

  14. Site fidelity, mate fidelity, and breeding dispersal in American kestrels

    USGS Publications Warehouse

    Steenhof, K.; Peterson, B.E.

    2009-01-01

    We assessed mate fidelity, nest-box fidelity, and breeding dispersal distances of American Kestrels (falco sparverius) nesting in boxes in southwestern Idaho from 1990 through 2006. Seventy-seven percent of boxes had different males and 87% had different females where nest-box occupants were identified in consecutive years. High turnover rates were partly a result of box-switching. Forty-eight percent of males and 58% of females that nested within the study area in successive years used different boxes. The probability of changing boxes was unrelated to gender, nesting success in the prior year, or years of nesting experience. Breeding dispersal distances for birds that moved to different boxes averaged 2.2 km for males (max = 22 km) and 3.2 km for females (max = 32 km). Approximately 70% of birds that nested in consecutive years on the study area had a different mate in the second year. Mate fidelity was related to box fidelity but not to prior nesting success or years of nesting experience. Mate changes occurred 32% of the time when the previous mate was known to be alive and nesting in the area. Kestrels that switched mates and boxes did not improve or decrease their subsequent nesting success. Kestrels usually switched to mates with less experience and lower lifetime productivity than their previous mates. The costs of switching boxes and mates were low, and there were no obvious benefits to fidelity. The cost of "waiting" for a previous mate that might have died could be high in species with high annual mortality.

  15. Efficacy of ovitrap colors and patterns for attracting Aedes albopictus at suburban field sites in North-Central Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We sought to visually enhance the attractiveness of a standard black ovitrap routinely used in surveillance of the Asian Tiger Mosquito, Aedes albopictus, and now being used as lethal ovitraps in Aedes aegypti dengue control programs. Black plastic drinking cups (ovitraps) were visually altered to ...

  16. Breeding sites and winter site fidelity of Piping Plovers wintering in The Bahamas, a previously unknown major wintering area

    USGS Publications Warehouse

    Gratto-Trevor, Cheri; Haig, Susan M.; Miller, Mark P.; Mullins, Thomas D.; Maddock, Sidney; Roche, Erin A.; Moore, Predensa

    2016-01-01

    Most of the known wintering areas of Piping Plovers (Charadrius melodus) are along the Atlantic and Gulf coasts of the United States and into Mexico, and in the Caribbean. However, 1066 threatened/endangered Piping Plovers were recently found wintering in The Bahamas, an area not previously known to be important for the species. Although representing about 27% of the birds counted during the 2011 International Piping Plover Winter Census, the location of their breeding site(s) was unknown. Thus, our objectives were to determine the location(s) of their breeding site(s) using molecular markers and by tracking banded individuals, identify spring and fall staging sites, and examine site fidelity and survival. We captured and color-banded 57 birds in January and February 2010 in The Bahamas. Blood samples were also collected for genetic evaluation of the likely subspecies wintering in The Bahamas. Band re-sightings and DNA analysis revealed that at least 95% of the Piping Plovers wintering in The Bahamas originated on the Atlantic coast of the United States and Canada. Re-sightings of birds banded in The Bahamas spanned the breeding distribution of the species along the Atlantic coast from Newfoundland to North Carolina. Site fidelity to breeding and wintering sites was high (88–100%). Spring and fall staging sites were located along the Atlantic coast of the United States, with marked birds concentrating in the Carolinas. Our estimate of true survival for the marked birds was 0.71 (95% CI: 0.61–0.80). Our results indicate that more than one third of the Piping Plover population that breeds along the Atlantic coast winters in The Bahamas. By determining the importance of The Bahamas to the Atlantic subspecies of Piping Plovers, future conservation efforts for these populations can be better focused on where they are most needed.

  17. Vacant Lots: Productive Sites for Aedes (Stegomyia) aegypti (Diptera: Culicidae) in Mérida City, México

    PubMed Central

    BAAK-BAAK, CARLOS M.; ARANA-GUARDIA, ROGER; CIGARROA-TOLEDO, NOHEMI; LOROÑO-PINO, MARÍA ALBA; REYES-SOLIS, GUADALUPE; MACHAIN-WILLIAMS, CARLOS; BEATY, BARRY J.; EISEN, LARS; GARCÍA-REJÓN, JULIÁN E.

    2014-01-01

    We assessed the potential for vacant lots and other non-residential settings to serve as source environments for Aedes (Stegomyia) aegypti (L.) in Mérida City, México. Mosquito immatures were collected, during November 2011 – June 2013, from residential premises (n = 156 site visits) and non-residential settings represented by vacant lots (50), parking lots (18), and streets/sidewalks (28). Collections totaled 46,025 mosquito immatures of 13 species. Ae. aegypti was the most commonly encountered species accounting for 81.0% of total immatures, followed by Culex quinquefasciatus Say (12.1%). Site visits to vacant lots (74.0%) were more likely to result in collection of Ae. aegypti immatures that residential premises (35.9%). Tires accounted for 75.5% of Ae. aegypti immatures collected from vacant lots. Our data suggest that vacant lots should be considered for inclusion in mosquito surveillance and control efforts in Mérida City, as they often are located near homes, commonly have abundant vegetation, and frequently harbor accumulations of small and large discarded water-holding containers that we now have demonstrated to serve as development sites for immature mosquitoes. Additionally, we present data for associations of immature production with various container characteristics, such as storage capacity, water quality and physical location in the environment. PMID:24724299

  18. Vacant lots: productive sites for Aedes (Stegomyia) aegypti (Diptera: Culicidae) in Mérida City, México.

    PubMed

    Baak-Baak, Carlos M; Arana-Guardia, Roger; Cigarroa-Toledo, Nohemi; Loroño-Pino, Maria Alba; Reyes-Solis, Guadalupe; Machain-Williams, Carlos; Beaty, Barry J; Eisen, Lars; García-Rejón, Julián E

    2014-03-01

    We assessed the potential for vacant lots and other nonresidential settings to serve as source environments for Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) in Mérida City, México. Mosquito immatures were collected, during November 2011-June 2013, from residential premises (n = 156 site visits) and nonresidential settings represented by vacant lots (50), parking lots (18), and streets or sidewalks (28). Collections totaled 46,025 mosquito immatures of 13 species. Ae. aegypti was the most commonly encountered species accounting for 81.0% of total immatures, followed by Culex quinquefasciatus Say (12.1%). Site visits to vacant lots (74.0%) were more likely to result in collection of Ae. aegypti immatures than residential premises (35.9%). Tires accounted for 75.5% of Ae. aegypti immatures collected from vacant lots. Our data suggest that vacant lots should be considered for inclusion in mosquito surveillance and control efforts in Mérida City, as they often are located near homes, commonly have abundant vegetation, and frequently harbor accumulations of small and large discarded water-holding containers that we now have demonstrated to serve as development sites for immature mosquitoes. In addition, we present data for associations of immature production with various container characteristics, such as storage capacity, water quality, and physical location in the environment. PMID:24724299

  19. Effects of natal habitat odour, reinforced by adult experience, on choice of oviposition site in the mosquito Aedes aegypti.

    PubMed

    Hamilton, C E; Beresford, D V; Sutcliffe, J F

    2011-12-01

    The effects of natal experience on the oviposition behaviour of adult female mosquitoes were investigated in the laboratory using Aedes aegypti (L.) (Diptera: Culicidae). 'Treatment' mosquitoes were exposed to a dilute repellent (inducing stimulus) in their breeding water (aquatic stages) and/or in the air (adults) during various combinations of life stages [larval only (L regime); larval and pupal (LP regime); larval, pupal and emergent adult (LPE regime); larval, pupal, emergent adult and adult (LPEA regime); pupal, emergent adult and adult (PEA regime); adult only (A regime)]. 'Control' mosquitoes were raised in an identical manner, but were not exposed to the inducing stimulus. The oviposition behaviour of treatment and control females was assessed in an oviposition assay that presented a choice of water with or without the inducing stimulus. Of the 435 mosquitoes tested in the experiment, 176 were non-distributors (i.e. laid all of their eggs in only one of the choices). Treatment females (distributors plus non-distributors) reared in the presence of the inducing stimulus throughout their lives (LPEA regime) showed a significant preference for the oviposition option containing the inducing stimulus (24/36 females) compared with corresponding controls (5/39 females). Distributors reared under the LPEA and PEA regimes also showed this preference (6/6 treatment vs. 2/29 control females, and 13/18 treatment vs. 7/23 control females, respectively). Females that had been exposed to the inducing stimulus as either immatures or adults only showed no preference for, and some showed an aversion to, the treatment oviposition option. This is interpreted as evidence for a natal habitat preference induction (NHPI) in this species, albeit one that requires extensive reinforcement in the adult stage. This adult experience-reinforced NHPI (AER-NHPI) is discussed in terms of its adaptive significance for container breeders, the possible timing mechanism and sensory basis of

  20. Breeding site selection by coho salmon (Oncorhynchus kisutch) in relation to large wood additions and factors that influence reproductive success

    USGS Publications Warehouse

    Clark, Steven M.; Dunham, Jason B.; McEnroe, Jeffery R.; Lightcap, Scott W.

    2014-01-01

    The fitness of female Pacific salmon (Oncorhynchus spp.) with respect to breeding behavior can be partitioned into at least four fitness components: survival to reproduction, competition for breeding sites, success of egg incubation, and suitability of the local environment near breeding sites for early rearing of juveniles. We evaluated the relative influences of habitat features linked to these fitness components with respect to selection of breeding sites by coho salmon (Oncorhynchus kisutch). We also evaluated associations between breeding site selection and additions of large wood, as the latter were introduced into the study system as a means of restoring habitat conditions to benefit coho salmon. We used a model selection approach to organize specific habitat features into groupings reflecting fitness components and influences of large wood. Results of this work suggest that female coho salmon likely select breeding sites based on a wide range of habitat features linked to all four hypothesized fitness components. More specifically, model parameter estimates indicated that breeding site selection was most strongly influenced by proximity to pool-tail crests and deeper water (mean and maximum depths). Linkages between large wood and breeding site selection were less clear. Overall, our findings suggest that breeding site selection by coho salmon is influenced by a suite of fitness components in addition to the egg incubation environment, which has been the emphasis of much work in the past.

  1. Common Grackle breeding on bottomland forest restoration sites

    USGS Publications Warehouse

    Twedt, Daniel J.

    2011-01-01

    Two of 36 forest restoration sites in the Mississippi Alluvial Valley surveyed from 2000-2002 harbored Quiscalus quiscula (Common Grackle). Occupied sites were in less-forested landscapes and had sparser understory vegetation due to flooding. Probability of daily nest survival (0.9077) of 169 Common Grackle nests was influenced by nest-placement, temporal, and landscape effects. Age of nest markedly affected nest survival, which increased from 0.92 when nestlings were present (age > 18 days). Extrapolating daily nest survival to a 31 -day nest period resulted in 5% nest success, far less then previously estimated for this species in more northern latitudes and likely less than required to sustain populations on these sites.

  2. Breeding bird populations and habitat associations within the Savannah River Site (SRS).

    SciTech Connect

    Gauthreaux, Sidney, A.; Steven J. Wagner.

    2005-06-29

    Gauthreaux, Sidney, A., and Steven J. Wagner. 2005. Breeding bird populations and habitat associations within the Savannah River Site (SRS). Final Report. USDA Forest Service, Savannah River, Aiken, SC. 48 pp. Abstract: During the 1970's and 1980's a dramatic decline occurred in the populations of Neotropical migratory birds, species that breed in North America and winter south of the border in Central and South America and in the Caribbean. In 1991 an international initiative was mounted by U. S. governmental land management agencies, nongovernmental conservation agencies, and the academic and lay ornithological communities to understand the decline of Neotropical migratory birds in the Americas. In cooperation with the USDA Forest Service - Savannah River (FS - SR) we began 1992 a project directed to monitoring population densities of breeding birds using the Breeding Bird Census (BBC) methodology in selected habitats within the Savannah River Site SRS. In addition we related point count data on the occurrence of breeding Neotropical migrants and other bird species to the habitat data gathered by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service and data on habitat treatments within forest stands.

  3. Sergentomyia spp.: breeding sites in vertisols and peri-domestic habitats in North West Ethiopia.

    PubMed

    Moncaz, Aviad; Kirstein, Oscar; Gebresellassie, Araya; Lemma, Wossenseged; Gebre-Michael, Teshome; Balkew, Meshesha; Belay, Shewaye; Hailu, Asrat; Warburg, Alon

    2014-09-01

    Sand flies belonging to the genus Sergentomyia Franca & Parrot, 1920, are hematophagous insects feeding mostly on reptiles and birds, but some species feed also on mammals including humans. Sergentomyia spp. frequently comprise the vast majority of sand flies trapped along with Phlebotomus spp., the vectors of mammalian leishmaniasis. Within the framework of a project on the ecology and transmission of visceral leishmaniasis in Ethiopia, putative breeding sites of phlebotomine sand flies were studied. Large horizontal sticky traps (LHSTs) covered with sand fly-proof mesh were deployed over cracked vertisol and related habitats for up to 3 nights, and emerging sand flies were collected daily. Emergence traps (ETs) were also adapted to sample other putative breeding sites including tree trunks, termite mounds, rock piles and vertical river banks. Productive breeding sites were identified in the trunks and roots systems of trees, vertisol fields, cracks and burrows in vertisol dry river banks and termite mounds. Emerging flies were also collected form a stone wall and a rock pile situated inside a village. Significantly more Sergentomyia spp. were trapped in vertisols by ETs deployed over root system than in open fields. Similarly, more sand flies emerged from cracks in the vertisol in fallow Sorghum than in fallow sesame fields. Productive breeding sites were characterized by stable micro-climatic conditions. Species composition of emerging sand flies varied with habitat, season and geographical location. PMID:24841132

  4. Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar

    PubMed Central

    2012-01-01

    Background In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML) method with the gene time reversible (GTR) model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p < 2.2 × 10-16) and period (F = 36.22, p = 2.548 × 10-13), that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough to discern

  5. Mate fidelity and breeding site tenacity in a monogamous sandpiper, the black turnstone

    USGS Publications Warehouse

    Handel, C.M.; Gill, R.E., Jr.

    2000-01-01

    We examined the relationship between mate fidelity and breeding site tenacity during a 5-year study of the black turnstone, Arenaria melanocephala, a socially monogamous sandpiper breeding in subarctic Alaska. We tested the predictions of several hypotheses regarding the incidence of divorce and the benefits of fidelity to mate and breeding site. Interannual return rates to the breeding grounds (88% for males, 79% for females) were among the highest yet recorded for any scolopacid sandpiper, and 88% of returning birds nested on their previous year's territory. The annual divorce rate was only 11%, and mate fidelity was significantly linked to fidelity to territory but independent of sex and year. Males arrived in spring significantly earlier than their mates and interannual fidelity was influenced by the relative timing of arrival of pair members. Reunited pairs had significantly higher fledging success than new pairs formed after death or divorce. The incidence of divorce was unrelated to reproductive success the previous year, although birds nested significantly further away after failure than after a successful nesting attempt. Sightings of marked individuals suggested that members of pairs do not winter together, and breeding site tenacity provides a mechanism through which pair members can reunite. We reject the 'incompatibility' hypothesis for divorce in turnstones, and our data contradict predictions of the 'better option' hypothesis. Alternatively, we propose the 'bet-hedging' hypothesis to explain the occurrence of divorce, which transpires when an individual pairs with a new mate to avoid the cost of waiting for a previous mate to return. Such costs can include remaining unmated, if the former mate has died, or experiencing lower reproductive success because of delayed breeding.

  6. Mate fidelity and breeding site tenacity in a monogamous sandpiper, the black turnstone.

    PubMed

    Handel; Gill

    2000-10-01

    We examined the relationship between mate fidelity and breeding site tenacity during a 5-year study of the black turnstone, Arenaria melanocephala, a socially monogamous sandpiper breeding in subArctic Alaska. We tested the predictions of several hypotheses regarding the incidence of divorce and the benefits of fidelity to mate and breeding site. Interannual return rates to the breeding grounds (88% for males, 79% for females) were among the highest yet recorded for any scolopacid sandpiper, and 88% of returning birds nested on their previous year's territory. The annual divorce rate was only 11%, and mate fidelity was significantly linked to fidelity to territory but independent of sex and year. Males arrived in spring significantly earlier than their mates and interannual fidelity was influenced by the relative timing of arrival of pair members. Reunited pairs had significantly higher fledging success than new pairs formed after death or divorce. The incidence of divorce was unrelated to reproductive success the previous year, although birds nested significantly further away after failure than after a successful nesting attempt. Sightings of marked individuals suggested that members of pairs do not winter together, and breeding site tenacity provides a mechanism through which pair members can reunite. We reject the 'incompatibility' hypothesis for divorce in turnstones, and our data contradict predictions of the 'better option' hypothesis. Alternatively, we propose the 'bet-hedging' hypothesis to explain the occurrence of divorce, which transpires when an individual pairs with a new mate to avoid the cost of waiting for a previous mate to return. Such costs can include remaining unmated, if the former mate has died, or experiencing lower reproductive success because of delayed breeding. Copyright 2000 The Association for the Study of Animal Behaviour. PMID:11032650

  7. Oviposition Behavior in Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Response to the Presence of Heterospecific and Conspecific Larvae.

    PubMed

    Gonzalez, Paula V; González Audino, Paola A; Masuh, Héctor M

    2016-03-01

    In mosquitoes, location of suitable sites for oviposition requires a set of visual, tactile, and olfactory cues that influences females before laying their eggs. The ability of gravid females to distinguish among potential oviposition sites that will or will not support the growth, development, and survival of their progeny is critical. Aedes aegypti (L.) and Aedes albopictus (Skuse) share ecological niches, being highly competitive in larval stage. We studied the oviposition behavior of both species in the presence of larvae of one or the other species (heterospecific or conspecific larvae). The number of eggs laid by gravid females on oviposition sites (water with different or the same species of Aedes larvae) were compared. The presence and density of heterospecific or conspecific larvae had a positive or negative effect on the ovipositional responses, measured as an oviposition activity index. For both species, the oviposition was not affected by heterospecific larvae with densities between 10 and 100 larvae in water, but a strong attractant behavior was observed for a density of 500 larvae in water. For Ae. albopictus in the presence of larvae of the same species (conspecific oviposition), we observed an attractant effect for larvae density of 10 but not for 100 or 500 larvae in water. Instead, for Ae. aegypti, we observed attraction only for 100 larvae, not for 10 or 500 larvae. Results presented here provide an additional insight about oviposition behavior responses of gravid females in the presence of conspecific and heterospecific larvae in breeding sites. PMID:26634825

  8. Reduction in dengue cases observed during mass control of Aedes (Stegomyia) in street catch basins in an endemic urban area in Colombia

    PubMed Central

    Ocampo, Clara B.; Mina, Neila Julieth; Carabalí, Mabel; Alexander, Neal; Osorio, Lyda

    2015-01-01

    Dengue incidence continues to increase globally and, in the absence of an efficacious vaccine, prevention strategies are limited to vector control. It has been suggested that targeting the most productive breeding sites instead of all water-holding containers could be a cost-effective vector control strategy. We sought to identify and continuously control the most productive Aedes (Stegomyia) breeding site in an endemic urban area in Colombia and followed the subsequent incidence of dengue. In the urban area of Guadalajara de Buga, southwestern Colombia, potential breeding sites inside and outside houses were first characterized, and local personnel trained to assess their productivity based on the pupae/person index. Simultaneously, training and monitoring were implemented to improve the dengue case surveillance system. Entomological data and insecticide resistance studies were used to define the targeted intervention. Then, a quasi-experimental design was used to assess the efficacy of the intervention in terms of the positivity index of the targeted and non- targeted breeding sites, and the impact on dengue cases. Street catch basins (storm drains) were the potential breeding site most frequently found containing Aedes immature stages in the baseline (58.3% of 108). Due to the high resistance to temephos (0% mortality after 24 h), the intervention consisted of monthly application of pyriproxyfen in all the street catch basins (n = 4800). A significant decrease in catch basins positivity for Aedes larvae was observed after each monthly treatment (p < 0.001). Over the intervention period, a reduction in the dengue incidence in Buga was observed (rate ratio 0.19, 95% CI 0.12–0.30, p < 0.0001) after adjusting for autocorrelation and controlling with a neighboring town, Palmira, This study highlights the importance of street catch basins as Aedes breeding sites and suggests that their targeted control could help to decrease dengue transmission in such areas. PMID

  9. Reduction in dengue cases observed during mass control of Aedes (Stegomyia) in street catch basins in an endemic urban area in Colombia.

    PubMed

    Ocampo, Clara B; Mina, Neila Julieth; Carabalí, Mabel; Alexander, Neal; Osorio, Lyda

    2014-04-01

    Dengue incidence continues to increase globally and, in the absence of an efficacious vaccine, prevention strategies are limited to vector control. It has been suggested that targeting the most productive breeding sites instead of all water-holding containers could be a cost-effective vector control strategy. We sought to identify and continuously control the most productive Aedes (Stegomyia) breeding site in an endemic urban area in Colombia and followed the subsequent incidence of dengue. In the urban area of Guadalajara de Buga, southwestern Colombia, potential breeding sites inside and outside houses were first characterized, and local personnel trained to assess their productivity based on the pupae/person index. Simultaneously, training and monitoring were implemented to improve the dengue case surveillance system. Entomological data and insecticide resistance studies were used to define the targeted intervention. Then, a quasi-experimental design was used to assess the efficacy of the intervention in terms of the positivity index of the targeted and non- targeted breeding sites, and the impact on dengue cases. Street catch basins (storm drains) were the potential breeding site most frequently found containing Aedes immature stages in the baseline (58.3% of 108). Due to the high resistance to temephos (0% mortality after 24h), the intervention consisted of monthly application of pyriproxyfen in all the street catch basins (n=4800). A significant decrease in catch basins positivity for Aedes larvae was observed after each monthly treatment (p<0.001). Over the intervention period, a reduction in the dengue incidence in Buga was observed (rate ratio 0.19, 95% CI 0.12-0.30, p<0.0001) after adjusting for autocorrelation and controlling with a neighboring town, Palmira, This study highlights the importance of street catch basins as Aedes breeding sites and suggests that their targeted control could help to decrease dengue transmission in such areas. PMID:24388794

  10. [Identification of breeding sites of Anopheles sp. during part of the dry season in Jigawa, Nigeria].

    PubMed

    Marquetti, María del Carmen; Rojas, Lázara; Mohd Birniwa, Muktar; Sulaiman, Haruna U; Adamu, Hassana H

    2007-01-01

    A study was conducted in the state of Jigawa, Republic of Nigeria, from November to December in the dry season, where malaria is one of the main morbidity and mortality causes particularly in under 5 years-old children and pregnant women. This state had two climate seasons: dry from October to May and rainy from June to September. A total of 112 water bodies were sampled and just 18 in nine local governments were positive to mosquitoes. Breeding sites for Anopheles were rice fields, small holes in land, animal footsteps, small ponds, flooded pasture fields and water treatment dam, among others, to amount to 10 sites. Contrary to what has always been reported about the presence of Anopheles in clean waters, they were also breeding in highly polluted waters containing human faeces and garbage and located in open sewers. PMID:23427452

  11. Efficacy of a mermithid nematode Romanomermis iyengari (Welch) (Nematoda: Mermithidae) in controlling tree hole-breeding mosquito Aedes albopictus (Skuse) (Diptera: Culicidae) in a rubber plantation area of Kerala, India.

    PubMed

    Paily, K P; Chandhiran, K; Vanamail, P; Kumar, N Pradeep; Jambulingam, P

    2013-03-01

    In rubber plantations, tree holes are one of the major types of breeding habitats of Aedes mosquitoes which transmit dengue and chikungunya. A mermithid nematode, Romanomermis iyengari, was evaluated in tree holes for its efficacy in controlling Aedes albopictus. Infection of mosquito larvae by the nematode was determined through microscopic examination on the next day of application, and evaluation of immature density of mosquito was done on the seventh day. After application of the infective stage of the nematode in a host-parasite ratio of 1:3 or 1:4, the infection rates on the different larval instars of mosquito were similar, 85.7-95.8 % in first to third instars and 79.3 % in fourth instar larvae or 100 and 92.9 %, respectively. Parasite burden varied from 1.1 to 2.4, respectively, among first and third instar larvae applied at 1:3. At 1:4, the parasite burden was between 1.6 (fourth instar) and 4 (second instar). The increase in parasite burden due to parasite density was significant in all the larval instars (P < 0.05). High parasite burden is detrimental to parasite recycling as it can cause premature mortality of the host. Hence, the dosage of 1:3 could be considered as suitable for rubber tree hole habitats. In the nematode-applied tree holes, there was a significant level (P < 0.05) of reduction in the immature density of A. albopictus, especially late instars and pupae, confirming the efficacy of R. iyengari in infecting the mosquito and controlling pupal emergence. PMID:23306387

  12. Long-lasting insecticide-treated house screens and targeted treatment of productive breeding-sites for dengue vector control in Acapulco, Mexico

    PubMed Central

    Che-Mendoza, Azael; Guillermo-May, Guillermo; Herrera-Bojórquez, Josué; Barrera-Pérez, Mario; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Arredondo-Jiménez, Juan I.; Sánchez-Tejeda, Gustavo; Vazquez-Prokopec, Gonzalo; Ranson, Hilary; Lenhart, Audrey; Sommerfeld, Johannes; McCall, Philip J.; Kroeger, Axel; Manrique-Saide, Pablo

    2015-01-01

    Background Long-lasting insecticidal net screens (LLIS) fitted to domestic windows and doors in combination with targeted treatment (TT) of the most productive Aedes aegypti breeding sites were evaluated for their impact on dengue vector indices in a cluster-randomised trial in Mexico between 2011 and 2013. Methods Sequentially over 2 years, LLIS and TT were deployed in 10 treatment clusters (100 houses/cluster) and followed up over 24 months. Cross-sectional surveys quantified infestations of adult mosquitoes, immature stages at baseline (pre-intervention) and in four post-intervention samples at 6-monthly intervals. Identical surveys were carried out in 10 control clusters that received no treatment. Results LLIS clusters had significantly lower infestations compared to control clusters at 5 and 12 months after installation, as measured by adult (male and female) and pupal-based vector indices. After addition of TT to the intervention houses in intervention clusters, indices remained significantly lower in the treated clusters until 18 (immature and adult stage indices) and 24 months (adult indices only) post-intervention. Conclusions These safe, simple affordable vector control tools were well-accepted by study participants and are potentially suitable in many regions at risk from dengue worldwide. PMID:25604761

  13. Efficacy of Ovitrap Colors and Patterns for Attracting Aedes albopictus (Diptera: Culicidae) at Suburban Field Sites in North Central Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We sought to visually enhance the attractiveness of a standard black ovitrap routinely used in surveillance of the Asian Tiger Mosquito, Aedes albopictus (Skuse), and now being used as lethal ovitraps in Ae. aegypti (L.) dengue control programs. Black plastic drinking cups (ovitraps) were visually ...

  14. Area-wide management of Aedes albopictus: choice of study sites based on geospatial characteristics, socioeconomic factors, and mosquito populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aedes (Stegomyia) albopictus (Skuse), the Asian tiger mosquito, is an introduced invasive species in the U.S. responsible for a significant proportion of service requests to local mosquito control programs. This container-utilizing mosquito is refractory to standard mosquito abatement measures in th...

  15. Prevalence of Aedes aegypti Linnaeus and Aedes albopictus Skuse in Koderma, Jharkhand.

    PubMed

    Singh, R K; Dhiman, R C; Dua, V K

    2011-09-01

    Entomological survey was carried out in different localities of Koderma district of Jharkhand with a view to study the prevalence, distribution and stratification of areas for Aedes mosquito species. A total of 233 houses were covered during house to house larval and adult survey. Aedes breeding could be detected in 157 houses. In all, a total of 942 domestic water containers were searched, out of which 461 were found positive. The overall house index(HI) container index(CI) breteau index(B1) and pupal index(PI) were 67.38%, 48.94%, 197.85% and 79.4%, respectively. The survey revealed that Aedes aegypti Linnaeus and Aedes albopictus Skuse are well established in Koderma with most of the areas showing high adult and larval indices. The preventive strategy needs to be directed towards minimizing the breeding potential of Aedes and water management practice by individuals along with implementation of urban bye-laws as well as IEC activities to contain Aedes breeding in future. PMID:23781636

  16. A Qualitative Evidence of the Breeding Sites of Anopheles arabiensis Patton (Diptera: Culicidae) in and Around Kassala Town, Eastern Sudan

    PubMed Central

    Hamza, Asma Mahmoud; El Rayah, El Amin

    2016-01-01

    Anopheles arabiensis Patton (Diptera: Culicidae) is considered the most efficient malaria vector in eastern Sudan. This study aims to characterize the breeding sites of An. arabiensis throughout the year in and around Kassala town, eastern Sudan. Diverse larval habitat types were visited and characterized based on the habitat type and chemical composition. Mosquito larvae were found in many diverse habitats. During the rainy season, rain pools and water bodies created by the seasonal Gash River serve as the main breeding sites. In the dry season, irrigation canals, seepage from water pipes, neglected wells, artificial containers, and man-made ditches serve as the main breeding sites. Breeding water showed a pH of 7.9 and a low concentration of the total dissolved salts. The results of this study may be considered in planning and implementing larval control programs in the area. PMID:27547039

  17. A Qualitative Evidence of the Breeding Sites of Anopheles arabiensis Patton (Diptera: Culicidae) in and Around Kassala Town, Eastern Sudan.

    PubMed

    Hamza, Asma Mahmoud; El Rayah, El Amin

    2016-01-01

    Anopheles arabiensis Patton (Diptera: Culicidae) is considered the most efficient malaria vector in eastern Sudan. This study aims to characterize the breeding sites of An. arabiensis throughout the year in and around Kassala town, eastern Sudan. Diverse larval habitat types were visited and characterized based on the habitat type and chemical composition. Mosquito larvae were found in many diverse habitats. During the rainy season, rain pools and water bodies created by the seasonal Gash River serve as the main breeding sites. In the dry season, irrigation canals, seepage from water pipes, neglected wells, artificial containers, and man-made ditches serve as the main breeding sites. Breeding water showed a pH of 7.9 and a low concentration of the total dissolved salts. The results of this study may be considered in planning and implementing larval control programs in the area. PMID:27547039

  18. Breeding season demography and movements of Eastern Towhees at the Savannah River Site, South Carolina

    USGS Publications Warehouse

    Krementz, D.G.; Powell, L.A.

    2000-01-01

    The Eastern Towhee (Pipilo erythrophthalmus) has undergone population declines across much of its range, especially in New England. Despite being a widespread and, at one time, a common species, relatively little is known about its natural history, ecology, or demographics. We conducted baseline research on Eastern Towhees at the Savannah River Site, South Carolina, in 1995 and 1996 to estimate breeding season survival rates, nest success rates, breeding densities, and daily movements. We also were interested in whether towhees had differences in survival and movement rates between young and mature managed pine stands. We found that survival rates during the breeding season of radio-marked towhees did not vary by sex or stand type. Daily nest success rates were very low [0.629 + 0.088 (SE)] as a result of high predation levels. Abundance estimates adjusted for sampling effort differed between years. In 1995, the abundance estimate was significantly lower in mature stands (7.1 + 0.47) than in-young stands (9.6 + 0.60) while in 1996, there was no different between mature stands (26.2 ? 5.67) and young stands (16.5 ? 3.39). Average daily movements by radio-marked towhees did not vary by sex or stand type. Movements among adjacent stands were common, and sometimes great distances.

  19. Mosquito species and outdoor breeding places in residential areas in Malaysia.

    PubMed

    Saleeza, S N R; Norma-Rashid, Y; Azirun, M Sofian

    2013-11-01

    We conducted mosquito surveillance at outdoor breeding habitat in 459 households at 7 urban locations in Putrajaya, Malaysia from January to December 2010 to determine the predominant species and breeding locations. The most common species found at all locations was Aedes albopictus. Gardening utensils were the most common breeding sites. Of the 1,885 mosquito larvae specimens found, 1,774 (94.1%) were Ae. albopictus larvae, 84 (4%) were Ae. aegypti larvae and 27 (1%) were Culex quinquefasciatus larvae. The Aedes index for each of the locations was higher than the goal set by the Ministry of Health for Malaysia. However, the container index at each of the locations was within the goal. The Breateau index was above the goal set by the Ministry of Health at Precinct 9B1 but the other locations were within the goal. PMID:24450233

  20. Peridomiciliary Breeding Sites of Phlebotomine Sand Flies (Diptera: Psychodidae) in an Endemic Area of American Cutaneous Leishmaniasis in Southeastern Brazil

    PubMed Central

    Vieira, Vivaldo Pim; Ferreira, Adelson Luiz; Biral dos Santos, Claudiney; Leite, Gustavo Rocha; Ferreira, Gabriel Eduardo Melim; Falqueto, Aloísio

    2012-01-01

    The occurrence of American cutaneous leishmaniasis (ACL) in areas modified by humans indicates that phlebotomine sand fly vectors breed close to human habitations. Potential peridomiciliary breeding sites of phlebotomines were sampled in an area of transmission of Leishmania (Viannia) braziliensis in Southeastern Brazil. Three concentric circles rounding houses and domestic animal shelters, with radii of 20, 40, and 60 m, defined the area to be monitored using adult emergence traps. Of the 67 phlebotomines collected, Lutzomyia intermedia comprised 71.6%; Lutzomyia schreiberi, 20.9%; and Lutzomyia migonei, 4.5%. The predominance of L. intermedia, the main species suspected of transmitting L. (V.) braziliensis in Southeastern Brazil, indicates its participation in the domiciliary transmission of ACL, providing evidence that the domiciliary ACL transmission cycle might be maintained by phlebotomines that breed close to human habitations. This finding might also help in planning measures that would make the peridomiciliary environment less favorable for phlebotomine breeding sites. PMID:23091196

  1. Comparison of the insecticide susceptibilities of laboratory strains of Aedes aegypti and Aedes albopictus.

    PubMed

    Gómez, Andrea; Seccacini, Emilia; Zerba, Eduardo; Licastro, Susana

    2011-12-01

    A susceptible strain of Aedes albopictus derived from the Gainesville strain (Florida, USA) was established in our laboratory. The larvicidal efficacies of the neurotoxic insecticides temephos, permethrin and the pure cis and trans-permethrin isomers and the microbial insecticide Bacillus thuringiensis israelensis (Bti) against Ae. albopictus were estimated and compared to a susceptible strain of Aedes aegypti. The larvicidal effect of insect growth regulator pyriproxyfen was also evaluated in both mosquito strains. The median lethal concentration/median emergency inhibition values for Ae. aegypti and Ae. albopictus, respectively, were: temephos, 3.058 and 6.632 ppb, permethrin, 3.143 and 4.933 ppb, cis-permethrin, 4.457 and 10.068 ppb, trans-permethrin, 1.510 and 3.883 ppb, Bti, 0.655 and 0.880 ppb and pyriproxyfen, 0.00774 and 0.01642 ppb. Ae. albopictus was more tolerant than Ae. aegypti to all six larvicides evaluated. The order of susceptibility for Ae. aegypti was pyriproxyfen > Bti > trans-permethrin > temephos > permethrin > cis-permethrin and for Ae. albopictus was pyriproxyfen > Bti > trans-permethrin > permethrin > temephos > cis-permethrin. Because both species can be found together in common urban, suburban and rural breeding sites, the results of this work provide baseline data on the susceptibility of Ae. albopictus to insecticides commonly used for controlling Ae. aegypti in the field. PMID:22241122

  2. Detection of potential mosquito breeding sites based on community sourced geotagged images

    NASA Astrophysics Data System (ADS)

    Agarwal, Ankit; Chaudhuri, Usashi; Chaudhuri, Subhasis; Seetharaman, Guna

    2014-06-01

    Various initiatives have been taken all over the world to involve the citizens in the collection and reporting of data to make better and informed data-driven decisions. Our work shows how the geotagged images collected through the general population can be used to combat Malaria and Dengue by identifying and visualizing localities that contain potential mosquito breeding sites. Our method first employs image quality assessment on the client side to reject the images with distortions like blur and artifacts. Each geotagged image received on the server is converted into a feature vector using the bag of visual words model. We train an SVM classifier on a histogram-based feature vector obtained after the vector quantization of SIFT features to discriminate images containing either a small stagnant water body like puddle, or open containers and tires, bushes etc. from those that contain flowing water, manicured lawns, tires attached to a vehicle etc. A geographical heat map is generated by assigning a specific location a probability value of it being a potential mosquito breeding ground of mosquito using feature level fusion or the max approach presented in the paper. The heat map thus generated can be used by concerned health authorities to take appropriate action and to promote civic awareness.

  3. Ross River virus risk associated with dispersal of Aedes (Ochlerotatus) camptorhynchus (Thomson) from breeding habitat into surrounding residential areas: muddy lakes, Western Australia.

    PubMed

    Jardine, Andrew; Neville, Peter J; Dent, Colin; Webster, Carla; Lindsay, Michael D A

    2014-07-01

    Rapid population growth in Western Australia has resulted in increased development of land for residential housing, and new developments are often proposed close to water because of intrinsic aesthetic values. However, this placement may place future residents at risk of mosquito-borne disease, of which Ross River virus (RRV) disease is the most common in Australia. Mosquito dispersal data were combined with a spatial analysis of human RRV cases to show that mosquitoes dispersed readily from larval habitat into surrounding low- and high-density residential areas and that residents living within 2 km of mosquito breeding habitat had a significantly higher rate of RRV disease. This finding highlights the importance of planning authorities in state and local governments to consider the implications of mosquito-borne disease risks when assessing residential development applications. PMID:24799370

  4. Validation of a Remote Sensing Model to Identify Simulium damnosum s.l. Breeding Sites in Sub-Saharan Africa

    PubMed Central

    Jacob, Benjamin G.; Novak, Robert J.; Toe, Laurent D.; Sanfo, Moussa; Griffith, Daniel A.; Lakwo, Thomson L.; Habomugisha, Peace; Katabarwa, Moses N.; Unnasch, Thomas R.

    2013-01-01

    Background Recently, most onchocerciasis control programs have begun to focus on elimination. Developing an effective elimination strategy relies upon accurately mapping the extent of endemic foci. In areas of Africa that suffer from a lack of infrastructure and/or political instability, developing such accurate maps has been difficult. Onchocerciasis foci are localized near breeding sites for the black fly vectors of the infection. The goal of this study was to conduct ground validation studies to evaluate the sensitivity and specificity of a remote sensing model developed to predict S. damnosum s.l. breeding sites. Methodology/Principal Findings Remote sensing images from Togo were analyzed to identify areas containing signature characteristics of S. damnosum s.l. breeding habitat. All 30 sites with the spectral signature were found to contain S. damnosum larvae, while 0/52 other sites judged as likely to contain larvae were found to contain larvae. The model was then used to predict breeding sites in Northern Uganda. This area is hyper-endemic for onchocerciasis, but political instability had precluded mass distribution of ivermectin until 2009. Ground validation revealed that 23/25 sites with the signature contained S. damnosum larvae, while 8/10 sites examined lacking the signature were larvae free. Sites predicted to have larvae contained significantly more larvae than those that lacked the signature. Conclusions/Significance This study suggests that a signature extracted from remote sensing images may be used to predict the location of S. damnosum s.l. breeding sites with a high degree of accuracy. This method should be of assistance in predicting communities at risk for onchocerciasis in areas of Africa where ground-based epidemiological surveys are difficult to implement. PMID:23936571

  5. A delay differential equation model for dengue transmission with regular visits to a mosquito breeding site

    NASA Astrophysics Data System (ADS)

    Yaacob, Y.; Yeak, S. H.; Lim, R. S.; Soewono, E.

    2015-03-01

    Dengue disease has been known as one of widely transmitted vector-borne diseases which potentially affects millions of people throughout the world especially in tropical and sub-tropical countries. One of the main factors contributing in the complication of the transmission process is the mobility of people in which people may get infection in the places far from their home. Here we construct a delay differential equation model for dengue transmission in a closed population where regular visits of people to a mosquito breeding site out of their residency such as traditional market take place daily. Basic reproductive ratio of the system is obtained and depends on the ratio between the outgoing rates of susceptible human and infective human. It is shown that the increase of mobility with different variation of mobility rates may contribute to different level of basic reproductive ratio as well as different level of outbreaks.

  6. ERTS surveys a 500 km squared locust breeding site in Saudi Arabia. [Red Sea coastal plain

    NASA Technical Reports Server (NTRS)

    Pedgley, D. E.

    1974-01-01

    From September 1972 to January 1973, ERTS-1 precisely located a 500 sq km area on the Red Sea coastal plain of Saudi Arabia within which the Desert Locust (Schistocerca gregaria, Forsk.) bred successfully and produced many small swarms. Growth of vegetation shown by satellite imagery was confirmed from ground surveys and raingauge data. The experiment demonstrates the feasibility of detecting potential locust breeding sites by satellite, and shows that an operational satellite would be a powerful tool for routine survey of the 3 x 10 to the 7th power sq km invasion area of the Desert Locust in Africa and Asia, as well as of other locust species in the arid and semi-arid tropics.

  7. Human disturbance and stage-specific habitat requirements influence snowy plover site occupancy during the breeding season.

    PubMed

    Webber, Alyson F; Heath, Julie A; Fischer, Richard A

    2013-04-01

    Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human disturbance, and habitat features between January and July 2009 and 2010. We made multiple visits during three different sampling periods that corresponded to snowy plover breeding: pre-breeding, incubation, and brood-rearing and used multi-season occupancy models to examine whether human disturbance, habitat features, or both influenced site occupancy, colonization (probability of transition from an unoccupied site to an occupied site), and extinction (probability of transition from an occupied site to an unoccupied site). Snowy plover site occupancy and colonization was negatively associated with human disturbance and site extinction was positively associated with human disturbance. Interdune vegetation had a negative effect on occupancy and colonization, indicating that plovers were less likely to use areas with uniform, dense vegetation among dunes. Also, dune shape, beach debris, and access to low-energy foraging areas influenced site occupancy, colonization, and extinction. Plovers used habitat based on beach characteristics that provided stage-specific resource needs; however, human disturbance was the strongest predictor of site occupancy. In addition, vegetation plantings used to enhance dune rehabilitation may negatively impact plover site occupancy. Management actions that decrease human disturbance, such as symbolic fencing and signage, may increase the amount of breeding habitat available to snowy plovers on the Florida Panhandle and in other areas with high human

  8. Human disturbance and stage-specific habitat requirements influence snowy plover site occupancy during the breeding season

    PubMed Central

    Webber, Alyson F; Heath, Julie A; Fischer, Richard A

    2013-01-01

    Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human disturbance, and habitat features between January and July 2009 and 2010. We made multiple visits during three different sampling periods that corresponded to snowy plover breeding: pre-breeding, incubation, and brood-rearing and used multi-season occupancy models to examine whether human disturbance, habitat features, or both influenced site occupancy, colonization (probability of transition from an unoccupied site to an occupied site), and extinction (probability of transition from an occupied site to an unoccupied site). Snowy plover site occupancy and colonization was negatively associated with human disturbance and site extinction was positively associated with human disturbance. Interdune vegetation had a negative effect on occupancy and colonization, indicating that plovers were less likely to use areas with uniform, dense vegetation among dunes. Also, dune shape, beach debris, and access to low-energy foraging areas influenced site occupancy, colonization, and extinction. Plovers used habitat based on beach characteristics that provided stage-specific resource needs; however, human disturbance was the strongest predictor of site occupancy. In addition, vegetation plantings used to enhance dune rehabilitation may negatively impact plover site occupancy. Management actions that decrease human disturbance, such as symbolic fencing and signage, may increase the amount of breeding habitat available to snowy plovers on the Florida Panhandle and in other areas with high human

  9. A comparison of two collection methods for estimating abundance and parity of Anopheles albimanus in breeding sites and villages of southern Mexico.

    PubMed

    Ulloa, A; Rodríguez, M H; Rodríguez, A D; Roberts, D R

    1997-09-01

    The abundance and age structure of Anopheles albimanus populations were estimated by UV updraft light traps and human landing catches within villages and in nearby breeding sites of southern México. Four villages and 5 breeding sites were selected for the study. Light trap and human landing catches were simultaneously carried out in each breeding site and each village. Anopheles albimanus was the most abundant malaria vector caught in breeding sites and in villages. Significant differences in overall An. albimanus abundance among villages and among breeding sites were detected only by human landing catches. In both villages and breeding sites, more mosquitoes were captured by 1 human bait (34.3 +/- 6.3 and 14.6 +/- 2.9, respectively) than by one light trap (15.9 +/- 3.3 and 2.4 +/- 0.3 respectively) collection. After pooling, no significant differences were detected in the abundance estimated by each method in breeding sites and villages. A significant correlation of numbers of specimens between methods was detected. Age structure was different between samples from breeding sites and villages, with more gravid females collected in breeding sites, whereas more nulipars were collected in villages. By collection method, age structure was also different both in breeding sites and in villages. In breeding sites, the percentage of parous females was significantly higher in human landing catches, whereas the percentage of gravid females was significantly higher in light traps. In villages, only the percentage of gravid females was significantly higher in light traps. Our results suggests that UV light traps could be used to measure several entomological parameters of An. albimanus populations because both abundance variations and parity rates were similarly detected by both methods. PMID:9383764

  10. A field test for competitive effects of Aedes albopictus on A. aegypti in South Florida: differences between sites of coexistence and exclusion?

    PubMed Central

    Juliano, Steven A.; Lounibos, L. Philip; O’Meara, George F.

    2007-01-01

    We tested whether interspecific competition from Aedes albopictus had measurable effects on A. aegypti at the typical numbers of larval mosquitoes found in cemetery vases in south Florida. We also tested whether the effect of interspecific competition from A. albopictus on A. aegypti differed between sites where A. aegypti either persists or went extinct following invasion by A. albopictus. Similar experiments manipulating numbers of A. albopictus in cemetery vases were conducted at three sites of A. aegypti persistence and three sites where A. aegypti was apparently extinct. The experiments were done using numbers of larvae that were determined by observed numbers of larvae for each site, and with resources (leaf detritus) that accumulated in experimental vases placed into each field site. In both the early rainy season (when number of mosquito larvae was low) and the late rainy season (when number of mosquito larvae was high), there was a significant effect of treatment on developmental progress of experimental A. aegypti. In the late rainy season, when numbers of larvae were high, there was also a significant effect of treatment on survivorship of A. aegypti. However, the competition treatment × site type (A. aegypti persists vs extinct) interaction was never significant, indicating that the competitive effect of A. albopictus on A. aegypti did not differ systematically between persistence versus extinction sites. Thus, although competition from A. albopictus is strong under field conditions at all sites, we find no evidence that variation in the impact of interspecific competition is associated with coexistence or exclusion. Interspecific competition among larvae is thus a viable explanation for exclusion or reduction of A. aegypti in south Florida, but variation in the persistence of A. aegypti following invasion does not seem to be primarily a product of variation in the conditions in the aquatic environments of cemetery vases. PMID:15024640

  11. Assessing the relationship between environmental factors and malaria vector breeding sites in Swaziland using multi-scale remotely sensed data.

    PubMed

    Dlamini, Sabelo Nick; Franke, Jonas; Vounatsou, Penelope

    2015-01-01

    Many entomological studies have analyzed remotely sensed data to assess the relationship between malaria vector distribution and the associated environmental factors. However, the high cost of remotely sensed products with high spatial resolution has often resulted in analyses being conducted at coarse scales using open-source, archived remotely sensed data. In the present study, spatial prediction of potential breeding sites based on multi-scale remotely sensed information in conjunction with entomological data with special reference to presence or absence of larvae was realized. Selected water bodies were tested for mosquito larvae using the larva scooping method, and the results were compared with data on land cover, rainfall, land surface temperature (LST) and altitude presented with high spatial resolution. To assess which environmental factors best predict larval presence or absence, Decision Tree methodology and logistic regression techniques were applied. Both approaches showed that some environmental predictors can reliably distinguish between the two alternatives (existence and non-existence of larvae). For example, the results suggest that larvae are mainly present in very small water pools related to human activities, such as subsistence farming that were also found to be the major determinant for vector breeding. Rainfall, LST and altitude, on the other hand, were less useful as a basis for mapping the distribution of breeding sites. In conclusion, we found that models linking presence of larvae with high-resolution land use have good predictive ability of identifying potential breeding sites. PMID:26054511

  12. Cloning and epitope mapping of Cry11Aa-binding sites in the Cry11Aa-receptor alkaline phosphatase from Aedes aegypti.

    PubMed

    Fernandez, Luisa E; Martinez-Anaya, Claudia; Lira, Erandi; Chen, Jianwu; Evans, Amy; Hernández-Martínez, Salvador; Lanz-Mendoza, Humberto; Bravo, Alejandra; Gill, Sarjeet S; Soberón, Mario

    2009-09-22

    Cry11Aa is the most active Bacillus thuringiensis israelensis toxin against Aedes aegypti larvae. Ae. aegypti alkaline phosphatase (ALP) was previously identified as a Cry11Aa receptor mediating toxicity. Here we report the cloning and functional characterization of this Ae. aegypti Cry11Aa-ALP receptor. Of three ALP's cDNA clones, the recombinant produced ALP1 isoform was shown to bind Cry11Aa and P1.BBMV peptide phage that specifically binds the midgut ALP-Cry11Aa receptor. An anti-ALP1 antibody inhibited binding to brush border membrane vesicles and toxicity of Cry11Aa in isolated cultured guts. Two ALP1 Cry11Aa binding regions (R59-G102 and N257-I296) were mapped by characterizing binding of Cry11Aa to nine recombinant overlapping peptides covering the ALP1 sequence. Finally, by using a peptide spot array of Cry11Aa domain III and site-directed mutagenesis, we show that the ALP1 R59-G102 region binds Cry11Aa through domain II loop alpha-8 while ALP1 N257-I296 interacts with Cry11Aa through domain III 561RVQSQNSGNN570 located in beta18-beta19. Our results show that Cry11Aa domain II and domain III are involved in the binding with two distinct binding sites in the ALP1 receptor. PMID:19697959

  13. Cloning and Epitope Mapping of Cry11Aa-Binding Sites in the Cry11Aa-Receptor Alkaline Phosphatase from Aedes aegypti†

    PubMed Central

    Fernandez, Luisa E.; Martinez-Anaya, Claudia; Lira, Erandi; Chen, Jianwu; Evans, Amy; Hernández-Martínez, Salvador; Lanz-Mendoza, Humberto; Bravo, Alejandra; Gill, Sarjeet S.; Soberón, Mario

    2013-01-01

    Cry11Aa is the most active Bacillus thuringiensis israelensis toxin against Aedes aegypti larvae. Ae. aegypti alkaline phosphatase (ALP) was previously identified as a Cry11Aa receptor mediating toxicity. Here we report the cloning and functional characterization of this Ae. aegypti Cry11Aa-ALP receptor. Of three ALP’s cDNA clones, the recombinant produced ALP1 isoform was shown to bind Cry11Aa and P1.BBMV peptide phage that specifically binds the midgut ALP-Cry11Aa receptor. An anti-ALP1 antibody inhibited binding to brush border membrane vesicles and toxicity of Cry11Aa in isolated cultured guts. Two ALP1 Cry11Aa binding regions (R59–G102 and N257–I296) were mapped by characterizing binding of Cry11Aa to nine recombinant overlapping peptides covering the ALP1 sequence. Finally, by using a peptide spot array of Cry11Aa domain III and site-directed mutagenesis, we show that the ALP1 R59–G102 region binds Cry11Aa through domain II loop α-8 while ALP1 N257–I296 interacts with Cry11Aa through domain III 561RVQSQNSGNN570 located in β18-β19. Our results show that Cry11Aa domain II and domain III are involved in the binding with two distinct binding sites in the ALP1 receptor. PMID:19697959

  14. Do male breeding displays function to attract mates or defend territories? The explanatory role of mate and site fidelity

    USGS Publications Warehouse

    Lanctot, Richard B.; Sandercock, B.K.; Kempenaers, B.

    2000-01-01

    Many shorebirds show elaborate breeding displays that include aerial flights and ground displays accompanied by song. The mate attraction hypothesis suggests that breeding displays function to attract mates and maintain pair bonds, whereas the territory defense hypothesis suggests breeding displays function in defining and defending nesting and feeding territories. We tested these hypotheses in the Western Sandpiper (Calidris mauri) by contrasting the duration and level of male breeding displays among pairs that differed in their mate and site fidelity. As predicted by the mate attraction hypothesis, males performed the highest number of song sequences during pair formation, and males paired with their mate of a prior year sang less than males paired to new mates. Further, site-faithful males mated to a new but experienced mate displayed significantly more than remated males or males new to the area. This suggests a male's prior familiarity with an area and his neighbors does not lessen his display rate as was predicted under the territory defense hypothesis. Limited support for the territory defense hypothesis came from observations of males performing breeding displays with neighboring males along nest territory boundaries. This behavior was short-lived, however, as males abandoned nesting areas after pair-formation and used adjacent or disjointed feeding areas during egg-laying and incubation. Male aggression (i.e., aerial and ground chases), as opposed to breeding displays, appeared to be the principal means of maintaining territory boundaries. Indeed, the rate at which males chased other males remained fairly constant and high throughout the breeding season. Male chasing behavior may also serve as a paternity guard to protect against extra-pair copulations. Our study also found that a female's prior breeding experience in an area correlated with a reduced display rate by her mate, particularly if that mate was new to the area. This indicates female

  15. Larvicidal and ovideterrent properties of neem oil and fractions against the filariasis vector Aedes albopictus (Diptera: Culicidae): a bioactivity survey across production sites.

    PubMed

    Benelli, Giovanni; Bedini, Stefano; Cosci, Francesca; Toniolo, Chiara; Conti, Barbara; Nicoletti, Marcello

    2015-01-01

    Neem seed oil (NSO) of Azadirachta indica (Meliaceae) contains more than 100 determined biologically active compounds, and many formulations deriving from them showed toxicity, antifeedancy and repellence against a number of arthropod pests. However, it is widely known that botanical products can differ in their chemical composition and bioactivity, as function of the production site and production process. We used high-performance thin layer chromatography (HPTLC) to investigate differences in chemical constituents of NSOs from three production sites. HPTLC analyses showed several differences in chemical abundance and diversity among NSOs, with special reference to limonoids. Furthermore, the three NSOs and their fractions of increasing polarities [i.e. ethyl acetate (EA) fraction and butanol (BU) fraction] were evaluated for larvicidal toxicity and field oviposition deterrence against the Asian tiger mosquito, Aedes albopictus, currently the most invasive mosquito worldwide. Results from bioactivity experiments showed good toxicity of NSOs and EA fractions against A. albopictus fourth instar larvae (with LC50 values ranging from 142.28 to 209.73 ppm), while little toxicity was exerted by BU fractions. A significant effect of the production site and dosage was also found and is probably linked to differences in abundance of constituents among samples, as highlighted by HPTLC analyses. NSOs and EAs were also able to deter A. albopictus oviposition in the field (effective repellence values ranging from 98.55 to 70.10%), while little effectiveness of BU fractions was found. Concerning ovideterrent activity, no difference due to the production site was found. This is the first report concerning larvicidal toxicity of NSO against A. albopictus and ovideterrence against Culicidae in the field. The chance to use chemicals from the NSO EA fraction seems promising, since they are effective at lower doses, if compared to synthetic products currently marketed, and could be

  16. [Identification of anopheles breeding sites in the residual foci of low malaria transmission «hotspots» in Central and Western Senegal].

    PubMed

    Sy, O; Konaté, L; Ndiaye, A; Dia, I; Diallo, A; Taïrou, F; Bâ, E L; Gomis, J F; Ndiaye, J L; Cissé, B; Gaye, O; Faye, O

    2016-02-01

    Malaria incidence has markedly declined in the Mbour, Fatick, Niakhar and Bambey districts (central and western Senegal) thanks to a scaling up of effective control measures namely LLINs (Long Lasting Insecticide Treated Net), ACTs (Artesunate Combination Therapy) and promoting care seeking. However malaria cases are now maintained by foci of transmission called hotspots. We evaluate the role of anopheles breeding sites in the identification of malaria hotspots in the health districts of Mbour, Fatick, Niakhar and Bambey. Surveys of breeding sites were made in 6 hotspot villages and 4 non-hotspot villages. A sample was taken in each water point with mosquito larvae by dipping method and the collected specimens were identified to the genus level. Additional parameters as name of the village and breeding sites, type of collection, original water turbidity, presence of vegetation, proximity to dwellings, geographic coordinates, sizes were also collected. Sixty-two water collections were surveyed and monitored between 2013 and 2014. Temporary natural breeding sites were predominant regardless of the epidemiological status of the village. Among the 31 breeding sites located within 500 meters of dwellings in hotspots villages, 70% carried Anopheles larvae during the rainy season while 43% of the 21 breeding sites located at similar distances in non-hotspot villages carried Anopheles larvae during the same period (P = 0.042). At the end of the rainy season, the trend is the same with 27% of positive breeding sites in hotspots and 14% in non-hotspots villages. The breeding sites encountered in hotspots villages are mostly small to medium size and are more productive by Anopheles larvae than those found in non-hotspot area. This study showed that the high frequency of smallest and productive breeding sites around and inside the villages can create conditions of residual transmission. PMID:26830896

  17. Hump-Shaped Density-Dependent Regulation of Mosquito Oviposition Site-Selection by Conspecific Immature Stages: Theory, Field Test with Aedes albopictus, and a Meta-Analysis

    PubMed Central

    Wasserberg, Gideon; Bailes, Nicholas; Davis, Christopher; Yeoman, Kim

    2014-01-01

    Oviposition site selection by gravid females is an important determinant of the distribution, abundance, and dynamics of dipteran hematophagous insects. The presence of conspecific immature stages in a potential oviposition site could, on the one hand, indicate the suitability of that site but on the other hand could indicate the potential for intraspecific competition. In this paper, we present a graphic model suggesting that the trade-off between these two opposing forces could result in a hump-shaped density-dependent relationship between oviposition rate and conspecific immature stage density (hereafter, the “Hump-shaped regulation model”) with positive effects of aggregation prevailing at low densities and negative effect of intraspecific competition prevailing at higher densities. We field-tested the predictions of this model at both the egg- and the larval levels with Aedes albopictus and evaluated if and how these relationships are affected by resource enrichment. We found support for the hump-shaped regulation model at both the larval and the egg levels. Using oviposition cups containing varying numbers of conspecific larvae, we showed that the oviposition activity of Ae. albopictus first increases and then decreases with larvae number. Medium enrichment resulted in higher hatching rate, and demonstrated linear relations for the no-enrichment treatment where larvae density range was low and hump-shaped relationship for the enriched medium that had a wider larvae density range. Using pairs of oviposition cups, we showed that at low egg densities mosquitoes laid more eggs on substrates containing pre-existing eggs. However, at higher egg densities, mosquitoes laid more eggs on a virgin substrate. Based on our results and on a meta-analysis, we suggest that due to study design or methodological shortcomings the hump-shaped regulation model is often left undetected and that it is likely to be more common than currently thought. PMID:24681526

  18. Dispersal of Engineered Male Aedes aegypti Mosquitoes

    PubMed Central

    Capurro, Margareth L.; Alphey, Luke; Donnelly, Christl A.; McKemey, Andrew R.

    2015-01-01

    Background Aedes aegypti, the principal vector of dengue fever, have been genetically engineered for use in a sterile insect control programme. To improve our understanding of the dispersal ecology of mosquitoes and to inform appropriate release strategies of ‘genetically sterile’ male Aedes aegypti detailed knowledge of the dispersal ability of the released insects is needed. Methodology/Principal Findings The dispersal ability of released ‘genetically sterile’ male Aedes aegypti at a field site in Brazil has been estimated. Dispersal kernels embedded within a generalized linear model framework were used to analyse data collected from three large scale mark release recapture studies. The methodology has been applied to previously published dispersal data to compare the dispersal ability of ‘genetically sterile’ male Aedes aegypti in contrasting environments. We parameterised dispersal kernels and estimated the mean distance travelled for insects in Brazil: 52.8m (95% CI: 49.9m, 56.8m) and Malaysia: 58.0m (95% CI: 51.1m, 71.0m). Conclusions/Significance Our results provide specific, detailed estimates of the dispersal characteristics of released ‘genetically sterile’ male Aedes aegypti in the field. The comparative analysis indicates that despite differing environments and recapture rates, key features of the insects’ dispersal kernels are conserved across the two studies. The results can be used to inform both risk assessments and release programmes using ‘genetically sterile’ male Aedes aegypti. PMID:26554922

  19. Nepenthes ampullaria (Nepenthaceae) Pitchers Are Unattractive to Gravid Aedes aegypti and Aedes albopictus (Diptera: Culicidae).

    PubMed

    Chou, Lee Yiung; Dykes, Gary A; Wilson, Robyn F; Clarke, Charles M

    2016-02-01

    Nepenthes pitcher plants are colonized by a variety of specialized arthropods. As Aedes mosquitoes are container breeders, Nepenthes pitchers are a potential candidate oviposition site for vector species, such as Aedes aegypti (L.) and Aedes albopictus (Skuse). However, Aedes spp. are not commonly encountered in Nepenthes pitchers, and the environment inside the pitchers of some species is lethal to them. One exception is Nepenthes ampullaria Jack, whose pitchers are known to be colonized by Ae. albopictus on very rare occasions. Given that Ae. albopictus larvae can survive in N. ampullaria pitcher fluids, we sought to determine why pitcher colonization is rare, testing the hypothesis that gravid Aedes mosquitoes are deterred from ovipositing into container habitats that have similar characteristics to N. ampullaria pitchers. Using plastic ovitraps of different sizes, colors, and with different types of fluids (based on the characteristics of N. ampullaria pitchers), we compared oviposition rates by Aedes mosquitoes in urban and rural areas within the geographical range of N. ampullaria near Kuala Lumpur, Malaysia. Ovitraps that were black and large (>250-ml capacity) accumulated significantly more eggs than ovitraps that were smaller, or green in color. In terms of size and color, small, green ovitraps are analogous to N. ampullaria pitchers, indicating that these pitchers are not particularly attractive to gravid Ae. albopictus. Although Aedes spp. are capable of colonizing N. ampullaria pitchers, the pitchers are relatively unattractive to gravid females and do not represent a significant habitat for larvae of dengue vectors at present. PMID:26518035

  20. Silencing of end-joining repair for efficient site-specific gene insertion after TALEN/CRISPR mutagenesis in Aedes aegypti

    PubMed Central

    Basu, Sanjay; Aryan, Azadeh; Overcash, Justin M.; Samuel, Glady Hazitha; Anderson, Michelle A. E.; Dahlem, Timothy J.; Myles, Kevin M.; Adelman, Zach N.

    2015-01-01

    Conventional control strategies for mosquito-borne pathogens such as malaria and dengue are now being complemented by the development of transgenic mosquito strains reprogrammed to generate beneficial phenotypes such as conditional sterility or pathogen resistance. The widespread success of site-specific nucleases such as transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 in model organisms also suggests that reprogrammable gene drive systems based on these nucleases may be capable of spreading such beneficial phenotypes in wild mosquito populations. Using the mosquito Aedes aegypti, we determined that mutations in the FokI domain used in TALENs to generate obligate heterodimeric complexes substantially and significantly reduce gene editing rates. We found that CRISPR/Cas9-based editing in the mosquito Ae. aegypti is also highly variable, with the majority of guide RNAs unable to generate detectable editing. By first evaluating candidate guide RNAs using a transient embryo assay, we were able to rapidly identify highly effective guide RNAs; focusing germ line-based experiments only on this cohort resulted in consistently high editing rates of 24–90%. Microinjection of double-stranded RNAs targeting ku70 or lig4, both essential components of the end-joining response, increased recombination-based repair in early embryos as determined by plasmid-based reporters. RNAi-based suppression of Ku70 concurrent with embryonic microinjection of site-specific nucleases yielded consistent gene insertion frequencies of 2–3%, similar to traditional transposon- or ΦC31-based integration methods but without the requirement for an initial docking step. These studies should greatly accelerate investigations into mosquito biology, streamline development of transgenic strains for field releases, and simplify the evaluation of novel Cas9-based gene drive systems. PMID:25775608

  1. Silencing of end-joining repair for efficient site-specific gene insertion after TALEN/CRISPR mutagenesis in Aedes aegypti.

    PubMed

    Basu, Sanjay; Aryan, Azadeh; Overcash, Justin M; Samuel, Glady Hazitha; Anderson, Michelle A E; Dahlem, Timothy J; Myles, Kevin M; Adelman, Zach N

    2015-03-31

    Conventional control strategies for mosquito-borne pathogens such as malaria and dengue are now being complemented by the development of transgenic mosquito strains reprogrammed to generate beneficial phenotypes such as conditional sterility or pathogen resistance. The widespread success of site-specific nucleases such as transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 in model organisms also suggests that reprogrammable gene drive systems based on these nucleases may be capable of spreading such beneficial phenotypes in wild mosquito populations. Using the mosquito Aedes aegypti, we determined that mutations in the FokI domain used in TALENs to generate obligate heterodimeric complexes substantially and significantly reduce gene editing rates. We found that CRISPR/Cas9-based editing in the mosquito Ae. aegypti is also highly variable, with the majority of guide RNAs unable to generate detectable editing. By first evaluating candidate guide RNAs using a transient embryo assay, we were able to rapidly identify highly effective guide RNAs; focusing germ line-based experiments only on this cohort resulted in consistently high editing rates of 24-90%. Microinjection of double-stranded RNAs targeting ku70 or lig4, both essential components of the end-joining response, increased recombination-based repair in early embryos as determined by plasmid-based reporters. RNAi-based suppression of Ku70 concurrent with embryonic microinjection of site-specific nucleases yielded consistent gene insertion frequencies of 2-3%, similar to traditional transposon- or ΦC31-based integration methods but without the requirement for an initial docking step. These studies should greatly accelerate investigations into mosquito biology, streamline development of transgenic strains for field releases, and simplify the evaluation of novel Cas9-based gene drive systems. PMID:25775608

  2. Breeding sites of Phlebotomus sergenti, the sand fly vector of cutaneous leishmaniasis in the Judean Desert.

    PubMed

    Moncaz, Aviad; Faiman, Roy; Kirstein, Oscar; Warburg, Alon

    2012-01-01

    Phlebotomine sand flies transmit Leishmania, phlebo-viruses and Bartonella to humans. A prominent gap in our knowledge of sand fly biology remains the ecology of their immature stages. Sand flies, unlike mosquitoes do not breed in water and only small numbers of larvae have been recovered from diverse habitats that provide stable temperatures, high humidity and decaying organic matter. We describe studies designed to identify and characterize sand fly breeding habitats in a Judean Desert focus of cutaneous leishmaniasis. To detect breeding habitats we constructed emergence traps comprising sand fly-proof netting covering defined areas or cave openings. Large size horizontal sticky traps within the confined spaces were used to trap the sand flies. Newly eclosed male sand flies were identified based on their un-rotated genitalia. Cumulative results show that Phlebotomus sergenti the vector of Leishmania tropica rests and breeds inside caves that are also home to rock hyraxes (the reservoir hosts of L. tropica) and several rodent species. Emerging sand flies were also trapped outside covered caves, probably arriving from other caves or from smaller, concealed cracks in the rocky ledges close by. Man-made support walls constructed with large boulders were also identified as breeding habitats for Ph. sergenti albeit less important than caves. Soil samples obtained from caves and burrows were rich in organic matter and salt content. In this study we developed and put into practice a generalized experimental scheme for identifying sand fly breeding habitats and for assessing the quantities of flies that emerge from them. An improved understanding of sand fly larval ecology should facilitate the implementation of effective control strategies of sand fly vectors of Leishmania. PMID:22802981

  3. Breeding Sites of Phlebotomus sergenti, the Sand Fly Vector of Cutaneous Leishmaniasis in the Judean Desert

    PubMed Central

    Moncaz, Aviad; Faiman, Roy; Kirstein, Oscar; Warburg, Alon

    2012-01-01

    Phlebotomine sand flies transmit Leishmania, phlebo-viruses and Bartonella to humans. A prominent gap in our knowledge of sand fly biology remains the ecology of their immature stages. Sand flies, unlike mosquitoes do not breed in water and only small numbers of larvae have been recovered from diverse habitats that provide stable temperatures, high humidity and decaying organic matter. We describe studies designed to identify and characterize sand fly breeding habitats in a Judean Desert focus of cutaneous leishmaniasis. To detect breeding habitats we constructed emergence traps comprising sand fly-proof netting covering defined areas or cave openings. Large size horizontal sticky traps within the confined spaces were used to trap the sand flies. Newly eclosed male sand flies were identified based on their un-rotated genitalia. Cumulative results show that Phlebotomus sergenti the vector of Leishmania tropica rests and breeds inside caves that are also home to rock hyraxes (the reservoir hosts of L. tropica) and several rodent species. Emerging sand flies were also trapped outside covered caves, probably arriving from other caves or from smaller, concealed cracks in the rocky ledges close by. Man-made support walls constructed with large boulders were also identified as breeding habitats for Ph. sergenti albeit less important than caves. Soil samples obtained from caves and burrows were rich in organic matter and salt content. In this study we developed and put into practice a generalized experimental scheme for identifying sand fly breeding habitats and for assessing the quantities of flies that emerge from them. An improved understanding of sand fly larval ecology should facilitate the implementation of effective control strategies of sand fly vectors of Leishmania. PMID:22802981

  4. Screening breeding sites of the common toad (Bufo bufo) in England and Wales for evidence of endocrine disrupting activity.

    PubMed

    Pickford, Daniel B; Jones, Alexandra; Velez-Pelez, Alejandra; Orton, Frances; Iguchi, Taisen; Mitsui, Naoko; Tooi, Osamu

    2015-07-01

    Anuran amphibians are often present in agricultural landscapes and may therefore be exposed to chemicals in surface waters used for breeding. We used passive accumulation devices (SPMD and POCIS) to sample contaminants from nine breeding sites of the Common toad (Bufo bufo) across England and Wales, measuring endocrine activity of the extracts in a recombinant yeast androgen screen (YAS) and yeast estrogen screen (YES) and an in vitro vitellogenin induction screen in primary culture of Xenopus laevis hepatocytes. We also assessed hatching, growth, survival, and development in caged larvae in situ, and sampled metamorphs for gonadal histopathology. None of the SPMD extracts exhibited estrogen receptor or androgen receptor agonist activity, while POCIS extracts from two sites in west-central England exhibited concentration-dependent androgenic activity in the YAS. Three sites exhibited significant estrogenic activity in both the YES and the Xenopus hepatocyte. Hatching rates varied widely among sites, but there was no consistent correlation between hatching rate and intensity of agricultural activity, predicted concentrations of agrochemicals, or endocrine activity measured in YES/YAS assays. While a small number of intersex individuals were observed, their incidence could not be associated with predicted pesticide exposure or endocrine activitity measured in the in vitro screens. There were no significant differences in sex ratio, as determined by gonadal histomorphology among the study sites, and no significant correlation was observed between proportion of males and predicted exposure to agrochemicals. However, a negative correlation did become apparent in later sampling periods between proportion of males and estrogenic activity of the POCIS sample, as measured in the YES. Our results suggest that larval and adult amphibians may be exposed to endocrine disrupting chemicals in breeding ponds, albeit at low concentrations, and that chemical contaminants other than

  5. Stormwater ponds, constructed wetlands, and other best management practices as potential breeding sites for West Nile virus vectors in Delaware during 2004.

    PubMed

    Gingrich, Jack B; Anderson, Robert D; Williams, Gregory M; O'Connor, Linda; Harkins, Kevin

    2006-06-01

    We performed longitudinal surveys of mosquito larval abundance (mean mosquito larvae per dip) in 87 stormwater ponds and constructed wetland in Delaware from June to September 2004. We analyzed selected water quality factors, water depth, types of vegetation, degree of shade, and level of insect predation in relation to mosquito abundance. The 2004 season was atypical, with most ponds remaining wet for the entire summer. In terms of West Nile virus (WNV) vectors, wetlands predominantly produce Aedes vexans, culex pipiens pipiens, and Culex restuans. Retention ponds generally produced the same species as wetlands, except that Cx. p. pipiens was more abundant than Cx. restuans in retention ponds. Aedes vexans and Culex salinarius were the most abundant species to Conservation Restoration Enhancement Program ponds. Sand filters uniquely produced high numbers of Cx. restuans, Cx. p. pipiens, and Aedes japonicus japonicus, a newly invasive vector species. Site that alternately dried and flooded, mostly detention ponds, forebays of retention ponds, and some wetlands often produced Ae. vexans, an occasional WNV bridge vector species. Overall, seasonal distribution of vectors was bimodal, with peaks occurring during early and late summer. Ponds with shallow sides and heavy shade generally produced an abundance of mosquitoes, unless insect predators were abundant. Bright, sunny ponds with steep sides and little vegetation generally produced the fewest mosquitoes. The associations among mosquito species and selected vegetation types are discussed. PMID:17019774

  6. Effects of Supplementary Feeding on the Breeding Ecology of the Buff-Throated Partridge in a Tibetan Sacred Site, China.

    PubMed

    Yang, Nan; Moermond, Timothy C; Lloyd, Huw; Xu, Yu; Dou, Liang; Zhang, Kai; Yue, Bisong; Ran, Jianghong

    2016-01-01

    Our goal was to document effects of year-round supplemental feeding on breeding ecology of the Buff-throated Partridge, Tetraophasis szechenyii, within a Tibetan sacred site. We evaluated effects of supplemental feeding used as religious/cultural practices which could potentially aid conservation of endangered phasianids. We compared fed breeding groups to neighboring nonfed groups. Fed groups initiated first clutches significantly earlier than nonfed groups. Earlier laying groups within fed and nonfed groups showed significantly lower hatching rates than later groups; however, fed groups showed significantly higher hatching rates than nonfed groups laying in the same period. Earlier laying increased opportunities to renest. All six fed groups with clutch failures renested compared to only one of five nonfed groups with clutch failures. Fed female breeders showed significantly greater investment in their young with larger clutches and larger eggs, which likely increased survivability of early hatchlings. We observed no predation on birds at feeding sites and recorded only four cases of predation on incubating females, which showed no detectable difference between fed and nonfed groups. Ground-nesting birds typically face high risks of predation. Ten of the 48 groups nested in trees, which occurs in few phasianid species. Tree nests showed significantly higher hatching rates compared to ground nests; however, we found no significant difference in tree nesting between fed and nonfed groups. This partridge is one of four gallinaceous species with cooperative breeding. Breeding groups with helpers had significantly greater reproductive success than single pairs, and fed female breeders with helpers laid bigger eggs than single pairs. Comparing annual reproductive output per group, fed groups not only produced significantly more independent young (≥ 150 days post-hatching), their young hatched significantly earlier, which likely have greater reproductive value over

  7. Effects of Supplementary Feeding on the Breeding Ecology of the Buff-Throated Partridge in a Tibetan Sacred Site, China

    PubMed Central

    Yang, Nan; Moermond, Timothy C.; Lloyd, Huw; Xu, Yu; Dou, Liang; Zhang, Kai; Yue, Bisong; Ran, Jianghong

    2016-01-01

    Our goal was to document effects of year-round supplemental feeding on breeding ecology of the Buff-throated Partridge, Tetraophasis szechenyii, within a Tibetan sacred site. We evaluated effects of supplemental feeding used as religious/cultural practices which could potentially aid conservation of endangered phasianids. We compared fed breeding groups to neighboring nonfed groups. Fed groups initiated first clutches significantly earlier than nonfed groups. Earlier laying groups within fed and nonfed groups showed significantly lower hatching rates than later groups; however, fed groups showed significantly higher hatching rates than nonfed groups laying in the same period. Earlier laying increased opportunities to renest. All six fed groups with clutch failures renested compared to only one of five nonfed groups with clutch failures. Fed female breeders showed significantly greater investment in their young with larger clutches and larger eggs, which likely increased survivability of early hatchlings. We observed no predation on birds at feeding sites and recorded only four cases of predation on incubating females, which showed no detectable difference between fed and nonfed groups. Ground-nesting birds typically face high risks of predation. Ten of the 48 groups nested in trees, which occurs in few phasianid species. Tree nests showed significantly higher hatching rates compared to ground nests; however, we found no significant difference in tree nesting between fed and nonfed groups. This partridge is one of four gallinaceous species with cooperative breeding. Breeding groups with helpers had significantly greater reproductive success than single pairs, and fed female breeders with helpers laid bigger eggs than single pairs. Comparing annual reproductive output per group, fed groups not only produced significantly more independent young (≥150 days post-hatching), their young hatched significantly earlier, which likely have greater reproductive value over

  8. Breeding site fidelity and winter admixture in a long-distance migrant, the tufted duck (Aythya fuligula)

    PubMed Central

    Liu, Y; Keller, I; Heckel, G

    2012-01-01

    Long-distance migrants are, by definition, highly mobile but it is poorly understood if this leads to high rates of gene flow and an essentially panmictic global population structure. Genetic divergence in migratory species could be promoted, for example, by fidelity to distinct migratory pathways. In this study, we investigate the population genetic structure of tufted duck (Aythya fuligula), a long-distance migrant with a largely continuous breeding distribution across Eurasia. Distinct, longitudinally oriented flyways have been postulated based on geographically disjunct wintering areas and are supported by evidence from ringing data. We generated sequences of the mitochondrial control region and multi-locus microsatellite genotypes for several hundreds of samples from the European and Asian breeding and wintering grounds including some individuals infected with highly pathogenic avian influenza virus H5N1. Significant differentiation between breeding sites was observed for both marker types, but FST values were approximately 10 times higher for maternally inherited mitochondrial DNA than for biparentally transmitted nuclear markers. The genetic differentiation between the postulated European and Asian flyways was similar to that observed within continents and, in general, genetic divergence was not associated with geographic distance. Neither marker type showed evidence of genetic substructure among aggregations on the European wintering grounds. Our results suggest some breeding site fidelity, especially in females, but extensive population admixture on the wintering grounds. Several scenarios may explain the observed lack of genetic divergence between Europe and Asia including non-equilibrium conditions following a recent range expansion or contemporary gene flow across the postulated migratory divides. PMID:22549516

  9. Integration of Research with Long-Term Monitoring: Breeding Wood Ducks on the Savannah River Site

    SciTech Connect

    Kennamer, R.A.; Hepp, G.R.

    2000-10-01

    In 1981, long-term monitoring of breeding wood ducks was initiated. Females were marked and recaptured for 15 years and annual population parameters were developed. Precise parameter estimates were possible due to high capture rates. The results contribute to the long-term understanding of wood duck populations.

  10. DETERMINATION OF BREEDING SITES OF NEMATODES IN A MUNICIPAL DRINKING WATER FACILITY

    EPA Science Inventory

    The question concerning the source of nematodes in finished water has been answered by clearly demonstrating that these invertebrates do not breed in the sand filter or another part of the water treatment facility but in the raw water source. The benthic layer of the rivers and l...

  11. Reclamation of mosquito breeding sites using Landsat-8 remote sensing data: A case study of Birnin Kebbi, Nigeria

    NASA Astrophysics Data System (ADS)

    Amusuk, Danboyi Joseph; Hashim, Mazlan; Beiranvand Pour, Amin

    2016-06-01

    It is believed by recent releases of World Health Organization (WHO) that more than half of the world's population (3.2 billion) live in areas that are at risk of malaria transmission. Although increased efforts are dramatically reducing the malaria burden in some places where the rate of new cases indicates a fall by 37% globally and 60% death rate. Unfortunately, the subSaharan Africa still shares 89% of malaria and 91% of malaria deaths. Essentially, attacking the causative vectors and reclamation of the vector breeding sites could be remarkable for the rolling back the malaria epidemic project. Consequently, it is essential to explore the possibility of using recent Landsat-8 data remote sensing data and applications of Geographic Information System (GIS) technique in contributing to the realization of this objective. This investigation used for identifying mosquito breeding habitat (Derelict Ponds) zones the application of supervised classification of the Landsat-8 image in conjunction with GIS layering which allowed identification of high risk prone regions for mosquito breeding habitat. The methodology delineated 10 spatial locations of the Derelict Ponds (DP) spread around the Birnin Kebbi urban environment. Moreover, the results combined with comparative analysis of the link between warm climatic (temperature and rainfall data) conditions and Malaria prevalence that is associated with urban poverty. This study indicates that the application of Landsat-8 data and GIS techniques can be a useful tool for planning and management of environmental health and mapping of hot spot environmental problem areas.

  12. Breeding site heterogeneity reduces variability in frog recruitment and population dynamics

    USGS Publications Warehouse

    McCaffery, Rebecca M.; Eby, Lisa A.; Maxell, Bryce A.; Corn, Paul Stephen

    2013-01-01

    Environmental stochasticity can have profound effects on the dynamics and viability of wild populations, and habitat heterogeneity provides one mechanism by which populations may be buffered against the negative effects of environmental fluctuations. Heterogeneity in breeding pond hydroperiod across the landscape may allow amphibian populations to persist despite variable interannual precipitation. We examined recruitment dynamics over 10 yr in a high-elevation Columbia spotted frog (Rana luteiventris) population that breeds in ponds with a variety of hydroperiods. We combined these data with matrix population models to quantify the consequences of heterogeneity in pond hydroperiod on net recruitment (i.e. number of metamorphs produced) and population growth rates. We compared our heterogeneous system to hypothetical homogeneous environments with only ephemeral ponds, only semi-permanent ponds, and only permanent ponds. We also examined the effects of breeding pond habitat loss on population growth rates. Most eggs were laid in permanent ponds each year, but survival to metamorphosis was highest in the semi-permanent ponds. Recruitment success varied by both year and pond type. Net recruitment and stochastic population growth rate were highest under a scenario with homogeneous semi-permanent ponds, but variability in recruitment was lowest in the scenario with the observed heterogeneity in hydroperiods. Loss of pond habitat decreased population growth rate, with greater decreases associated with loss of permanent and semi-permanent habitat. The presence of a diversity of pond hydroperiods on the landscape will influence population dynamics, including reducing variability in recruitment in an uncertain climatic future.

  13. Post-fledging dispersal of king penguins (Aptenodytes patagonicus) from two breeding sites in the South Atlantic.

    PubMed

    Pütz, Klemens; Trathan, Phil N; Pedrana, Julieta; Collins, Martin A; Poncet, Sally; Lüthi, Benno

    2014-01-01

    Most studies concerning the foraging ecology of marine vertebrates are limited to breeding adults, although other life history stages might comprise half the total population. For penguins, little is known about juvenile dispersal, a period when individuals may be susceptible to increased mortality given their naïve foraging behaviour. Therefore, we used satellite telemetry to study king penguin fledglings (n = 18) from two sites in the Southwest Atlantic in December 2007. The two sites differed with respect to climate and proximity to the Antarctic Polar Front (APF), a key oceanographic feature generally thought to be important for king penguin foraging success. Accordingly, birds from both sites foraged predominantly in the vicinity of the APF. Eight king penguins were tracked for periods greater than 120 days; seven of these (three from the Falkland Islands and four from South Georgia) migrated into the Pacific. Only one bird from the Falkland Islands moved into the Indian Ocean, visiting the northern limit of the winter pack-ice. Three others from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. Derived tracking parameters describing their migratory behaviour showed no significant differences between sites. Nevertheless, generalized linear habitat modelling revealed that juveniles from the Falkland Islands spent more time in comparatively shallow waters with low sea surface temperature, sea surface height and chlorophyll variability. Birds from South Georgia spent more time in deeper waters with low sea surface temperature and sea surface height, but high concentrations of chlorophyll. Our results indicate that inexperienced king penguins, irrespective of the location of their natal site in relation to the position of the APF, develop their foraging skills progressively over time, including specific adaptations to the environment around their prospective breeding site. PMID:24828545

  14. Post-Fledging Dispersal of King Penguins (Aptenodytes patagonicus) from Two Breeding Sites in the South Atlantic

    PubMed Central

    Pütz, Klemens; Trathan, Phil N.; Pedrana, Julieta; Collins, Martin A.; Poncet, Sally; Lüthi, Benno

    2014-01-01

    Most studies concerning the foraging ecology of marine vertebrates are limited to breeding adults, although other life history stages might comprise half the total population. For penguins, little is known about juvenile dispersal, a period when individuals may be susceptible to increased mortality given their naïve foraging behaviour. Therefore, we used satellite telemetry to study king penguin fledglings (n = 18) from two sites in the Southwest Atlantic in December 2007. The two sites differed with respect to climate and proximity to the Antarctic Polar Front (APF), a key oceanographic feature generally thought to be important for king penguin foraging success. Accordingly, birds from both sites foraged predominantly in the vicinity of the APF. Eight king penguins were tracked for periods greater than 120 days; seven of these (three from the Falkland Islands and four from South Georgia) migrated into the Pacific. Only one bird from the Falkland Islands moved into the Indian Ocean, visiting the northern limit of the winter pack-ice. Three others from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. Derived tracking parameters describing their migratory behaviour showed no significant differences between sites. Nevertheless, generalized linear habitat modelling revealed that juveniles from the Falkland Islands spent more time in comparatively shallow waters with low sea surface temperature, sea surface height and chlorophyll variability. Birds from South Georgia spent more time in deeper waters with low sea surface temperature and sea surface height, but high concentrations of chlorophyll. Our results indicate that inexperienced king penguins, irrespective of the location of their natal site in relation to the position of the APF, develop their foraging skills progressively over time, including specific adaptations to the environment around their prospective breeding site. PMID:24828545

  15. Distribution and habitat characterization of the recently introduced invasive mosquito Aedes koreicus [Hulecoeteomyia koreica], a new potential vector and pest in north-eastern Italy

    PubMed Central

    2013-01-01

    Background The container breeding species belonging to the genus Aedes (Meigen) are frequently recorded out of their place of origin. Invasive Aedes species are proven or potential vectors of important Arboviruses and their establishment in new areas pose a threat for human and animal health. A new species of exotic mosquito was recorded in 2011 in north-eastern Italy: Aedes (Finlaya) koreicus [Hulecoeteomyia koreica]. The aim of this study was to characterize the biology, the environment and the current distribution of this mosquito in north-eastern Italy. Morphological details useful to discriminate this species from other invasive Aedes mosquitoes are also given (see Additional files). Methods All possible breeding sites for larval development were monitored. In addition, ovitraps and traps for adults were used to collect eggs and adults. The mosquitoes (larvae and adults) were identified morphologically and molecularly. Environmental data and climatic variables during the period of mosquito activity (from April to October) were considered. Results Aedes koreicus was found in 37 municipalities (39.4%) and was detected in 40.2% of places and in 37.3% of larval habitats monitored, in a range of altitude from 173 to 1250 m.a.s.l.. Garden centres were the most common locations (66.7%), followed by streets/squares (57.1%), private gardens (46.4%) and cemeteries (21.1%) (p < 0.01). The main larval habitats were catch basins (48.5%) and artificial water containers (41.8%). As for Aedes albopictus [Stegomyia albopicta], ovitraps were attractive for adult females resulting in the higher rate of positivity (15/21; 71.4%) among breeding sites. The period of Ae. koreicus activity ranged from March 29 to October 29. Conclusion The species is clearly established in the area and is now overlapping with other vectors such as Ae. albopictus and colonizing areas over 800 m.a.s.l, not yet or sporadically reached by the tiger mosquito. The data collected are essential to

  16. Spatial and Temporal Heterogeneities of Aedes albopictus Density in La Reunion Island: Rise and Weakness of Entomological Indices

    PubMed Central

    Boyer, Sebastien; Foray, Coralie; Dehecq, Jean-Sebastien

    2014-01-01

    Following the 2006 Chikungunya disease in La Reunion, questions were raised concerning the monitoring survey of Aedes albopictus populations and the entomological indexes used to evaluate population abundance. The objectives of the present study were to determine reliable productivity indexes using a quantitative method to improve entomological surveys and mosquito control measures on Aedes albopictus. Between 2007 and 2011, 4 intervention districts, 24 cities, 990 areas and over 850,000 houses were used to fulfil those objectives. Four indexes including the classical Stegomyia index (House Index, Container Index, Breteau Index) plus an Infested Receptacle Index were studied in order to determine whether temporal (year, month, week) and/or spatial (districts, cities, areas) heterogeneities existed. Temporal variations have been observed with an increase of Ae. albopictus population density over the years, and a seasonality effect with a highest population during the hot and wet season. Spatial clustering was observed at several scales with an important autocorrelation at the area scale. Moreover, the combination among these results and the breeding site productivity obtained during these 5 years allowed us to propose recommendations to monitor Aedes albopictus by eliminating not the most finding sites but the most productive ones. As the other strategies failed in La Reunion, this new approach should should work better. PMID:24637507

  17. Spatial and temporal heterogeneities of Aedes albopictus density in La Reunion Island: rise and weakness of entomological indices.

    PubMed

    Boyer, Sebastien; Foray, Coralie; Dehecq, Jean-Sebastien

    2014-01-01

    Following the 2006 Chikungunya disease in La Reunion, questions were raised concerning the monitoring survey of Aedes albopictus populations and the entomological indexes used to evaluate population abundance. The objectives of the present study were to determine reliable productivity indexes using a quantitative method to improve entomological surveys and mosquito control measures on Aedes albopictus. Between 2007 and 2011, 4 intervention districts, 24 cities, 990 areas and over 850,000 houses were used to fulfil those objectives. Four indexes including the classical Stegomyia index (House Index, Container Index, Breteau Index) plus an Infested Receptacle Index were studied in order to determine whether temporal (year, month, week) and/or spatial (districts, cities, areas) heterogeneities existed. Temporal variations have been observed with an increase of Ae. albopictus population density over the years, and a seasonality effect with a highest population during the hot and wet season. Spatial clustering was observed at several scales with an important autocorrelation at the area scale. Moreover, the combination among these results and the breeding site productivity obtained during these 5 years allowed us to propose recommendations to monitor Aedes albopictus by eliminating not the most finding sites but the most productive ones. As the other strategies failed in La Reunion, this new approach should should work better. PMID:24637507

  18. Pulsed resources at tundra breeding sites affect winter irruptions at temperate latitudes of a top predator, the snowy owl.

    PubMed

    Robillard, A; Therrien, J F; Gauthier, G; Clark, K M; Bêty, J

    2016-06-01

    Irruptive migration is mostly observed in species specialized on pulsed resources and is thought to be a response to unpredictable changes in food supply. We assessed two alternative hypotheses to explain the periodic winter irruptions of snowy owls Bubo scandiacus every 3-5 years in temperate North America: (a) the lack-of-food hypothesis, which states that a crash in small mammal abundance on the Arctic breeding grounds forces owls to move out of the tundra massively to search for food in winter; (b) the breeding-success hypothesis, which states that high abundance of tundra small mammals during the summer allows for high production of young, thus increasing the pool of migrants moving south the following winter. We modeled winter irruptions of snowy owls in relation to summer food resources and geographic location. Winter abundance of owls was obtained from citizen-based surveys from 1994 to 2011 and summer abundance of small mammals was collected in summer at two distant sites in Canada: Bylot Island, NU (eastern High Arctic) and Daring Lake, NWT (central Low Arctic). Winter owl abundance was positively related to prey abundance during the previous summer at both sites and tended to decrease from western to eastern temperate North America. Irruptive migration of snowy owls was therefore best explained by the breeding success hypothesis and was apparently caused by large-scale summer variations in food. Our results, combined with previous findings, suggest that the main determinants of irruptive migration may be species specific even in a guild of apparently similar species. PMID:26920901

  19. Annual survival estimation of migratory songbirds confounded by incomplete breeding site-fidelity: Study designs that may help

    USGS Publications Warehouse

    Marshall, M.R.; Diefenbach, D.R.; Wood, L.A.; Cooper, R.J.

    2004-01-01

    Many species of bird exhibit varying degrees of site-fidelity to the previous year's territory or breeding area, a phenomenon we refer to as incomplete breeding site-fidelity. If the territory they occupy is located beyond the bounds of the study area or search area (i.e., they have emigrated from the study area), the bird will go undetected and is therefore indistinguishable from dead individuals in capture-mark-recapture studies. Differential emigration rates confound inferences regarding differences in survival between sexes and among species if apparent survival rates are used as estimates of true survival. Moreover, the bias introduced by using apparent survival rates for true survival rates can have profound effects on the predictions of population persistence through time, source/sink dynamics, and other aspects of life-history theory. We investigated four study design and analysis approaches that result in apparent survival estimates that are closer to true survival estimates. Our motivation for this research stemmed from a multi-year capture-recapture study of Prothonotary Warblers (Protonotaria citrea) on multiple study plots within a larger landscape of suitable breeding habitat where substantial inter-annual movements of marked individuals among neighboring study plots was documented. We wished to quantify the effects of this type of movement on annual survival estimation. The first two study designs we investigated involved marking birds in a core area and resighting them in the core as well as an area surrounding the core. For the first of these two designs, we demonstrated that as the resighting area surrounding the core gets progressively larger, and more "emigrants" are resighted, apparent survival estimates begin to approximate true survival rates (bias < 0.01). However, given observed inter-annual movements of birds, it is likely to be logistically impractical to resight birds on sufficiently large surrounding areas to minimize bias. Therefore

  20. Evidence for natural vertical transmission of chikungunya viruses in field populations of Aedes aegypti in Delhi and Haryana states in India-a preliminary report.

    PubMed

    Jain, Jaspreet; Kushwah, Raja Babu S; Singh, Shashi S; Sharma, Anil; Adak, Tridibes; Singh, Om P; Bhatnagar, Raj Kamal; Subbarao, Sarala K; Sunil, Sujatha

    2016-10-01

    Aedes aegypti and Aedes albopictus are principal vectors for the transmission of chikungunya virus (CHIKV). India is a hub for both dengue and chikungunya infections and there are several reports of co-infection of dengue and chikungunya virus in the clinical scenario. The present pilot entomological survey was conducted to evaluate vertical transmission of CHIKV in Aedes field populations. Aedes immature (larvae and pupae) collection was done in 2012, over a period of six months from selected sites in Delhi and Haryana, India. The immatures collected were reared for adult emergence and species identification was done. A. aegypti male and female mosquitoes were separated and pooled collection spot-wise, RNA extracted and RT PCR performed to test for the presence of CHIKV in the pools. Container index (CI) and minimum infection rate (MIR) were estimated. From study areas that tested positive for CHIKV, adult collections were made and females upon feeding on uninfected blood in laboratory were allowed to lay eggs. The progeny that emerged from these field-collected mothers were tested for CHIKV presence. Our pilot survey showed the existence of A. aegypti population even during peak summer season in a few foci which eventually helped the mosquitoes to tide over adverse environmental conditions and with the start of rainfall, the population exploded within a short period of time. Immatures collected from field and progeny of adults collected from the field were CHIKV positive demonstrating the presence of vertical transmission of chikungunya virus in field population of A. aegypti. The present study further demonstrates the importance of identifying permanent breeding sites for proper Aedes species control. PMID:27282096

  1. Breeding biology and nest-site selection of red-tailed hawks in an altered desert grassland

    USGS Publications Warehouse

    Hobbs, R.J.; DeStefano, S.; Halvorson, W.L.

    2006-01-01

    Red-tailed Hawks (Buteo jamaicensis) have expanded their range as trees have invaded formerly-open grasslands. Desert grasslands of southern Arizona have been invaded by mesquite trees (Prosopis velutina) since Anglo-American settlement and now support a large population of Red-tailed Hawks. We studied a population of Red-tailed Hawks in an altered desert grassland in southern Arizona. Our objectives were to determine what environmental characteristics influence Red-tailed Hawk habitat selection in mesquite-invaded desert grasslands and to evaluate the habitat quality of these grasslands for Red-tailed Hawks based on nesting density, nest success, and productivity. Red-tailed Hawks had 86% (95% C.I. = 73-99) nest success and 1.82 young per breeding pair (95% C.I. = 1.41-2.23). Nesting density was 0.15 (95% CI = 0.08-0.21) breeding pairs/km2 and the mean nearest-neighbor distance was 1.95 km (95% C.I. = 1.74-2.16). Red-tailed Hawks selected nest-sites with taller nest-trees and greater tree height and cover than were available at random. Mesquite trees in desert grasslands provide abundant potential nesting structures for Red-tailed Hawks. ?? 2006 The Raptor Research Foundation, Inc.

  2. Potential Risk of Dengue and Chikungunya Outbreaks in Northern Italy Based on a Population Model of Aedes albopictus (Diptera: Culicidae)

    PubMed Central

    Montarsi, Fabrizio; Baldacchino, Frédéric Alexandre; Metz, Markus; Capelli, Gioia; Rizzoli, Annapaola; Pugliese, Andrea; Rosà, Roberto; Poletti, Piero; Merler, Stefano

    2016-01-01

    The rapid invasion and spread of Aedes albopictus (Skuse, 1894) within new continents and climatic ranges has created favorable conditions for the emergence of tropical arboviral diseases in the invaded areas. We used mosquito abundance data from 2014 collected across ten sites in northern Italy to calibrate a population model for Aedes albopictus and estimate the potential of imported human cases of chikungunya or dengue to generate the condition for their autochthonous transmission in the absence of control interventions. The model captured intra-year seasonality and heterogeneity across sites in mosquito abundance, based on local temperature patterns and the estimated site-specific mosquito habitat suitability. A robust negative correlation was found between the latter and local late spring precipitations, indicating a possible washout effect on larval breeding sites. The model predicts a significant risk of chikungunya outbreaks in most sites if a case is imported between the beginning of summer and up to mid-November, with an average outbreak probability between 4.9% and 25%, depending on the site. A lower risk is predicted for dengue, with an average probability between 4.2% and 10.8% for cases imported between mid-July and mid-September. This study shows the importance of an integrated entomological and medical surveillance for the evaluation of arboviral disease risk, which is a precondition for designing cost-effective vector control programs. PMID:27304211

  3. Effect of temperature on the population dynamics of Aedes aegypti

    NASA Astrophysics Data System (ADS)

    Yusoff, Nuraini; Tokachil, Mohd Najir

    2015-10-01

    Aedes aegypti is one of the main vectors in the transmission of dengue fever. Its abundance may cause the spread of the disease to be more intense. In the study of its biological life cycle, temperature was found to increase the development rate of each stage of this species and thus, accelerate the process of the development from egg to adult. In this paper, a Lefkovitch matrix model will be used to study the stage-structured population dynamics of Aedes aegypti. In constructing the transition matrix, temperature will be taken into account. As a case study, temperature recorded at the Subang Meteorological Station for year 2006 until 2010 will be used. Population dynamics of Aedes aegypti at maximum, average and minimum temperature for each year will be simulated and compared. It is expected that the higher the temperature, the faster the mosquito will breed. The result will be compared to the number of dengue fever incidences to see their relationship.

  4. Attractant and stimulant factors for oviposition of Culex pipiens fatigans in natural breeding-sites*

    PubMed Central

    Ikeshoji, Toshiaki

    1966-01-01

    The breeding of mosquito larvae in the field is determined by the ovipositing behaviour of the gravid females. Investigation of the chemical factors that induce oviposition is therefore important for understanding mosquito ecology. These substances may also prove to be useful in assessing and controlling mosquito populations. The author has demonstrated two chemical factors, an ovipositing attractant and an ovipositing stimulant, in surface-water. The ovipositing attractant, extracted from surface-water by distillation and extraction with diethyl ether, was found to be quite effective when used to recapture known numbers of gravid mosquitos released in a large calf-shed. The presence of the stimulant factor was established by forcing gravid females to touch the testing water with tarsi and proboscis. After such contact, they began oviposition three times more rapidly on surface-water than on tap-water. The importance of these factors was demonstrated in the larval populations of Culex pipiens fatigans in pit-latrines in Rangoon, Burma. PMID:5298039

  5. Can non-breeding be a cost of breeding dispersal?

    USGS Publications Warehouse

    Danchin, E.; Cam, E.

    2002-01-01

    Breeding habitat selection and dispersal are crucial processes that affect many components of fitness. Breeding dispersal entails costs, one of which has been neglected: dispersing animals may miss breeding opportunities because breeding dispersal requires finding a new nesting site and mate, two time- and energy-consuming activities. Dispersers are expected to be prone to non-breeding. We used the kittiwake (Rissa tridactyla) to test whether breeding dispersal influences breeding probability. Breeding probability was associated with dispersal, in that both were negatively influenced by private information (previous individual reproductive success) and public information (average reproductive success of conspecifics) about patch quality. Furthermore, the probability of skipping breeding was 1.7 times higher in birds that settled in a new patch relative to those that remained on the same patch. Finally, non-breeders that resumed breeding were 4.4 times more likely to disperse than birds that bred in successive years. Although private information may influence breeding probability directly, the link between breeding probability and public information may be indirect, through the influence of public information on breeding dispersal, non-breeding thus being a cost of dispersal. These results support the hypothesis that dispersal may result in not being able to breed. More generally, non-breeding (which can be interpreted as an extreme form of breeding failure) may reveal costs of various previous activities. Because monitoring the non-breeding portion of a population is difficult, non-breeders have been neglected in many studies of reproduction trade-offs.

  6. Real-time PCR Tests in Dutch Exotic Mosquito Surveys; Implementation of Aedes aegypti and Aedes albopictus Identification Tests, and the Development of Tests for the Identification of Aedes atropalpus and Aedes japonicus japonicus (Diptera: Culicidae).

    PubMed

    van de Vossenberg, B T L H; Ibáñez-Justicia, A; Metz-Verschure, E; van Veen, E J; Bruil-Dieters, M L; Scholte, E J

    2015-05-01

    Since 2009, The Netherlands Food and Consumer Product Safety Authority carries out surveys focusing on, amongst others, the presence of invasive mosquito species (IMS). Special attention is given to exotic container-breeding Aedes species Aedes aegypti (L.), Aedes albopictus (Skuse), Aedes atropalpus (Coquillett), and Aedes japonicus japonicus (Theobald). This study describes the implementation of real-time PCR tests described by Hill et al. (2008) for the identification of Ae. aegypti and Ae. albopictus, and the development of two novel real-time PCR tests for the identification of Ae. atropalpus and Ae. j. japonicus. Initial test showed that optimization of elements of the Ae. aegypti and Ae. albopictus tests was needed. Method validation tests were performed to determine if the implemented and newly developed tests are fit for routine diagnostics. Performance criteria of analytical sensitivity, analytical specificity, selectivity, repeatability, and reproducibility were determined. In addition, experiments were performed to determine the influence of environmental conditions on the usability of DNA extracted from mosquito specimens trapped in BG-Sentinel traps. The real-time PCR tests were demonstrated to be sensitive, specific, repeatable, reproducible, and are less prone to false negative results compared to partial cytochrome c oxidase I gene sequencing owing to the DNA fragmentation caused by environmental influences. PMID:26334807

  7. Temporal variation of allozyme frequencies in Aedes albifasciatus (Diptera: Culicidae) from Argentina.

    PubMed

    de Sousa, G B; Jiménez, A; Blanco, A; Gardenal, C N

    1997-12-01

    Aedes albifasciatus is a floodwater mosquito widely distributed in Argentina. It is important from economic and medical points of view. A 4-year survey of seasonal variation in allele frequencies in a population of this species was undertaken to determine possible changes in the genetic structure and their correlation with environmental conditions. Significant temporal variation was detected at most of the loci, but it did not follow a cyclic or seasonal pattern. Multivariate analysis of principal components showed a remarkable homogeneity of samples collected from December 1993 to April 1995 and a clear differentiation of the November 1991, March 1992, and November 1993 samples. This variation could be correlated with the magnitude of rainfall occurring in the area. Passive transport of larvae by water streams and river freshets produced by floods would have mixed larvae from breeding sites with different allele frequencies, causing the genetic differentiation observed. PMID:9559091

  8. Florida atlas of breeding sites for herons and their allies: 1976-1978

    SciTech Connect

    Nesbitt, S.A.; Ogden, J.C.; Kale, H.W. II; Patty, B.W.; Rowse, L.A.

    1982-08-01

    The first atlas of heron colonies was published in 1978 (Osborn and Custer 1978) and covered the Atlantic coast from Maine to Florida for 1975 and 1976. This atlas is an update of heron colonies for the Atlantic coast of Florida and an initial heron colony coverage for the Florida gulf Coast and inland colonies, 1976 through 1978. Aerial surveys were conducted in April and mid-summer over the Florida peninsula, east of the Ochlockonee River. A total of 295 active nesting colonies, with 22 different species, were located in the three-year period. Colony locations are shown on 1:250,000 USGS maps and Florida county maps. Colony data forms follow each county map and include information on location, date of census, estimated number of nesting pairs, site description, nesting substrate and proximity to human development.

  9. Aedes aegypti and Aedes albopictus Habitat Preferences in South Texas, USA

    PubMed Central

    Champion, Samantha R; Vitek, Christopher J

    2014-01-01

    The South Texas region has a historical record of occasional dengue outbreaks. The recent introduction of chikungunya virus to the Caribbean suggests that this disease may be a concern as well. Six different cities and three field habitat types (residential, tire shops, and cemeteries) were examined for evidence of habitat and longitudinal preference of two vector species, Aedes aegypti and Aedes albopictus. A. aegypti was more prevalent in tire shop sites, while A. albopictus was more prevalent in cemetery sites. In residential sites, the relative abundance of the two species varied with longitude, with A. albopictus being more abundant near the coast, and A. aegypti being more abundant inland. There was also a temporal variation, with A. aegypti declining in frequency over time in residential sites. These results have implications for control strategies and disease risk and suggest a greater need for increased surveillance and research in the region. PMID:25520559

  10. Aedes aegypti and Aedes albopictus Habitat Preferences in South Texas, USA.

    PubMed

    Champion, Samantha R; Vitek, Christopher J

    2014-01-01

    The South Texas region has a historical record of occasional dengue outbreaks. The recent introduction of chikungunya virus to the Caribbean suggests that this disease may be a concern as well. Six different cities and three field habitat types (residential, tire shops, and cemeteries) were examined for evidence of habitat and longitudinal preference of two vector species, Aedes aegypti and Aedes albopictus. A. aegypti was more prevalent in tire shop sites, while A. albopictus was more prevalent in cemetery sites. In residential sites, the relative abundance of the two species varied with longitude, with A. albopictus being more abundant near the coast, and A. aegypti being more abundant inland. There was also a temporal variation, with A. aegypti declining in frequency over time in residential sites. These results have implications for control strategies and disease risk and suggest a greater need for increased surveillance and research in the region. PMID:25520559

  11. A breeding site model for regional, dynamical malaria simulations evaluated using in situ temporary ponds observations.

    PubMed

    Asare, Ernest O; Tompkins, Adrian M; Amekudzi, Leonard K; Ermert, Volker

    2016-01-01

    Daily observations of potential mosquito developmental habitats in a suburb of Kumasi in central Ghana reveal a strong variability in their water persistence times, which ranged between 11 and 81 days. The persistence of the ponds was strongly tied with rainfall, location and size of the puddles. A simple power-law relationship is found to fit the relationship between the average pond depth and area well. A prognostic water balance model is derived that describes the temporal evolution of the pond area and depth, incorporating the power-law geometrical relation. Pond area increases in response to rainfall, while evaporation and infiltration act as sink terms. Based on a range of evaluation metrics, the prognostic model is judged to provide a good representation of the pond coverage evolution at most sites. Finally, we demonstrate that the prognostic equation can be generalised and equally applied to a grid-cell to derive a fractional pond coverage, and thus can be implemented in spatially distributed models for relevant vector- borne diseases such as malaria. PMID:27063734

  12. Eco-bio-social determinants of dengue vector breeding: a multicountry study in urban and periurban Asia

    PubMed Central

    Tana, Susilowati; Espino, Fe; Kittayapong, Pattamaporn; Abeyewickreme, Wimal; Wai, Khin Thet; Tyagi, Brij Kishore; Kroeger, Axel; Sommerfeld, Johannes; Petzold, Max

    2010-01-01

    Abstract Objective To study dengue vector breeding patterns under a variety of conditions in public and private spaces; to explore the ecological, biological and social (eco-bio-social) factors involved in vector breeding and viral transmission, and to define the main implications for vector control. Methods In each of six Asian cities or periurban areas, a team randomly selected urban clusters for conducting standardized household surveys, neighbourhood background surveys and entomological surveys. They collected information on vector breeding sites, people’s knowledge, attitudes and practices surrounding dengue, and the characteristics of the study areas. All premises were inspected; larval indices were used to quantify vector breeding sites, and pupal counts were used to identify productive water container types and as a proxy measure for adult vector abundance. Findings The most productive vector breeding sites were outdoor water containers, particularly if uncovered, beneath shrubbery and unused for at least one week. Peridomestic and intradomestic areas were much more important for pupal production than commercial and public spaces other than schools and religious facilities. A complex but non-significant association was found between water supply and pupal counts, and lack of waste disposal services was associated with higher vector abundance in only one site. Greater knowledge about dengue and its transmission was associated with lower mosquito breeding and production. Vector control measures (mainly larviciding in one site) substantially reduced larval and pupal counts and “pushed” mosquito breeding to alternative containers. Conclusion Vector breeding and the production of adult Aedes aegypti are influenced by a complex interplay of factors. Thus, to achieve effective vector management, a public health response beyond routine larviciding or focal spraying is essential. PMID:20428384

  13. Wildfire effects on water temperature and selection of breeding sites by the Boreal Toad (Bufo boreas) in seasonal wetlands

    USGS Publications Warehouse

    Hossack, B.R.; Corn, P.S.

    2008-01-01

    Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature, and accumulated growing degree days measured on the north shore of three classes of wetlands: unburned wetlands, burned wetlands that were colonized by breeding toads, and burned wetlands that were not colonized. We hypothesized that toads colonized burned wetlands because they were warmer than unburned wetlands and selected specific burned wetlands because they were warmer than neighboring burned sites. There was weak evidence that toads selected burned wetlands with higher temperature maxima; however, the differences were small (???1??C) and were not supported when accounting for geography and wetland features. We also found no evidence that burning the forest around wetlands increased water temperatures two and three years after the fire. Unburned wetlands had higher daily mean and maximum temperatures and accrued more growing degree days than either class of burned wetlands. Temperature differences among groups of wetlands seemed to be driven by subtle differences in geography. We suspect we did not find warmer temperatures in burned wetlands because all of the wetlands we monitored already had open canopies and the fire likely resulted in only small increases in incident radiation. Copyright ?? 2008. Blake R. Hossack. All rights reserved.

  14. Physico-chemical indices of breeding sites of Simulium damnosum in the lower Cross River Basin, Nigeria.

    PubMed

    Opara, K N; Fagbemi, B O

    2005-01-01

    To determine the factor influencing the abundance development and distribution of Simulium damnosum (S.I) immature stages in the lower Cross River Basin, Nigeria, the physico-chemical characteristics of water at breeding sites were analysed longitudinally over a 12 month period. Analysis of the water samples showed that water current correlated positively and significantly (p < 0.05), with dissolved oxygen (r = 0.95 vs 0.10); conductivity (r = 0.95 vs 0.81); hydrogen ion concentration (r = 0.03 vs 0.46); and biochemical oxygen demand (r = 0.80 vs 0.64); from Agbokim Waterfalls and Afi River respectively. The result indicates that these parameters and low ionic concentration are the most essential requirement for the development of S. damnosum pre-imaginal stages. Amplitudes of annual variability as measured by co-efficient of variation varied between the parameters. From the trends in hydrological variables it was deduced that the integrated impact of precipitation, input of surface runoff and municipal effluents played an overriding role in determining the absolute levels and temporal pattern in the water quality attributes. Of the 3578 pre-imaginal stages of S. damnosum collected, 52.52% and 47.4% were collected from Agbokim Waterfall and Afi River respectively. There was a significant difference (p < 0.05) in the number of pre-imaginal stages collected from both sites. The highest number of pre-imaginal stages of S. damnosum collected were at the peak of rain (July-September) indicating that S. damnosum in the River Basin is a wet season breeder. The need for long term laboratory colonization of blackfly immature stages becomes imperative especially how these parameters could be exploited in control programme through the testing of larvicides without adverse ecological damage to the aquatic habitat. PMID:16083137

  15. Desiccation resistance in Aedes aegypti and Aedes albopictus eggs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Causative influences that impact the separation of Aedes aegypti and Aedes albopictus populations in different geographic areas were determined. The eggs of Ae. albopictus and Ae. aegypti collected from McAllen and Brownsville, Texas, and laboratory populations of these two species were subjected t...

  16. Differentiation of Aedes aegypti and Aedes notoscriptus (Diptera: Culicidae) eggs using scanning electron microscopy.

    PubMed

    Faull, Katherine J; Williams, Craig R

    2016-05-01

    Aedes notoscriptus and Aedes aegypti are both peri-domestic, invasive container-breeding mosquitoes. While the two potential arboviral vectors are bionomically similar, their sympatric distribution in Australia is limited. In this study, analyses of Ae. aegypti and Ae. notoscriptus eggs were enabled using scanning electron microscopy. Significant variations in egg length to width ratio and outer chorionic cell field morphology between Ae. aegypti and Ae. notoscriptus enabled distinction of the two species. Intraspecific variations in cell field morphology also enabled differentiation of the separate populations of both species, highlighting regional and global variation. Our study provides a comprehensive comparative analysis of inter- and intraspecific egg morphological and morphometric variation between two invasive container-breeding mosquitoes. The results indicate a high degree of intraspecific variation in Ae. notoscriptus egg morphology when compared to the eggs of Ae. aegypti. Comparative morphological analyses of Ae. aegypti and Ae. notoscriptus egg attributes using SEM allows differentiation of the species and may be helpful in understanding egg biology in relation to biotope of origin. PMID:26845557

  17. Aedes albopictus (Diptera: Culicidae) Oviposition Preference as Influenced by Container Size and Buddleja davidii Plants.

    PubMed

    Davis, Timothy J; Kline, Daniel L; Kaufman, Phillip E

    2016-03-01

    Aedes albopictus (Skuse) is a container-breeding mosquito commonly found in residential areas of its range in the United States. Mosquitoes are known to utilize flowering plants for sugar acquisition. Limited information is known about the influences on oviposition site selection, outside of container size. Residential areas are often landscaped with a variety of flowering plants and are known to provide numerous sizes of potential larval developmental sites for container-breeding mosqutioes. Through screened enclosure and field studies, the oviposition preference of Ae. albopictus for containers of three selected sizes (473, 946 and 1,892 ml) and the influence of flowering butterfly bush (Buddleja davidii Franchett cultivar 'Guinevere') plants were examined. Our results document that significantly more eggs were oviposited in the largest containers. Additionally, significantly more eggs were oviposited in containers adjacent to flowering butterfly bushes than in those without a flowering butterfly bush. Finally, our results document that flowering butterfly bushes exerted greater influence over Ae. albopictus oviposition decisions than did container size. Our findings can be applied to several aspects of Ae. albopictus surveillance and control. PMID:26733402

  18. Temperature Characterization of Different Urban Microhabitats of Aedes albopictus (Diptera Culicidae) in Central-Northern Italy.

    PubMed

    Vallorani, Roberto; Angelini, Paola; Bellini, Romeo; Carrieri, Marco; Crisci, Alfonso; Mascali Zeo, Silvia; Messeri, Gianni; Venturelli, Claudio

    2015-08-01

    Aedes albopictus (Skuse) is an invasive mosquito species that has spread to many countries in temperate regions bordering the Mediterranean basin, where it is becoming a major public health concern. A good knowledge of the thermal features of the most productive breeding sites for Ae. albopictus is crucial for a better estimation of the mosquitoes' life cycle and developmental rates. In this article, we address the problem of predicting air temperature in three microhabitats common in urban and suburban areas and the air and water temperature inside an ordinary catch basin, which is considered the most productive breeding site for Ae. albopictus in Italy. Temperature differences were statistically proven between the three microhabitats and between the catch basin external and internal temperature. The impacts on the developmental rates for each life stage of Ae. albopictus were tested through a parametric function of the temperature, and the aquatic stages resulted as being the most affected using the specific temperature inside a typical catch basin instead of a generic air temperature. The impact of snow cover on the catch basin internal temperature, and consequently on the mortality of diapausing eggs, was also evaluated. These data can be useful to improve epidemiological models for a better prediction of Ae. albopictus seasonal and population dynamics in central-northern Italian urban areas. PMID:26314064

  19. Parentage of overlapping offspring of an arboreal-breeding frog with no nest defense: implications for nest site selection and reproductive strategy.

    PubMed

    Tung, Wan-Ping; Chen, Yi-Huey; Cheng, Wei-Chun; Chuang, Ming-Feng; Hsu, Wan-Tso; Kam, Yeong-Choy; Lehtinen, Richard M

    2015-01-01

    Overlapping offspring occurs when eggs are laid in a nest containing offspring from earlier reproduction. Earlier studies showed that the parentage is not always obvious due to difficulties in field observation and/or alternative breeding tactics. To unveil the parentage between overlapping offspring and parents is critical in understanding oviposition site selection and the reproductive strategies of parents. Amplectant pairs of an arboreal-breeding frog, Kurixalus eiffingeri, lay eggs in tadpole-occupied nests where offspring of different life stages (embryos and tadpoles) coexist. We used five microsatellite DNA markers to assess the parentage between parents and overlapping offspring. We also tested the hypothesis that the male or female frog would breed in the same breeding site because of the scarcity of nest sites. Results showed varied parentage patterns, which may differ from the phenomenon of overlapping egg clutches reported earlier. Parentage analyses showed that only 58 and 25% of the tadpole-occupied stumps were reused by the same male and female respectively, partially confirming our prediction. Re-nesting by the same individual was more common in males than females, which is most likely related to the cost of tadpole feeding and/or feeding schemes of females. On the other hand, results of parentage analyses showed that about 42 and 75% of male and female respectively bred in tadpole-occupied stumps where tadpoles were genetically unrelated. Results of a nest-choice experiment revealed that 40% of frogs chose tadpole-occupied bamboo cups when we presented identical stumps, without or with tadpoles, suggesting that the habitat saturation hypothesis does not fully explain why frogs used the tadpole-occupied stumps. Several possible benefits of overlapping offspring with different life stages were proposed. Our study highlights the importance of integrating molecular data with field observations to better understand the reproductive biology and nest

  20. Parentage of Overlapping Offspring of an Arboreal-Breeding Frog with No Nest Defense: Implications for Nest Site Selection and Reproductive Strategy

    PubMed Central

    Tung, Wan-Ping; Chen, Yi-Huey; Cheng, Wei-Chun; Chuang, Ming-Feng; Hsu, Wan-Tso; Kam, Yeong-Choy; Lehtinen, Richard M.

    2015-01-01

    Overlapping offspring occurs when eggs are laid in a nest containing offspring from earlier reproduction. Earlier studies showed that the parentage is not always obvious due to difficulties in field observation and/or alternative breeding tactics. To unveil the parentage between overlapping offspring and parents is critical in understanding oviposition site selection and the reproductive strategies of parents. Amplectant pairs of an arboreal-breeding frog, Kurixalus eiffingeri, lay eggs in tadpole-occupied nests where offspring of different life stages (embryos and tadpoles) coexist. We used five microsatellite DNA markers to assess the parentage between parents and overlapping offspring. We also tested the hypothesis that the male or female frog would breed in the same breeding site because of the scarcity of nest sites. Results showed varied parentage patterns, which may differ from the phenomenon of overlapping egg clutches reported earlier. Parentage analyses showed that only 58 and 25% of the tadpole-occupied stumps were reused by the same male and female respectively, partially confirming our prediction. Re-nesting by the same individual was more common in males than females, which is most likely related to the cost of tadpole feeding and/or feeding schemes of females. On the other hand, results of parentage analyses showed that about 42 and 75% of male and female respectively bred in tadpole-occupied stumps where tadpoles were genetically unrelated. Results of a nest-choice experiment revealed that 40% of frogs chose tadpole-occupied bamboo cups when we presented identical stumps, without or with tadpoles, suggesting that the habitat saturation hypothesis does not fully explain why frogs used the tadpole-occupied stumps. Several possible benefits of overlapping offspring with different life stages were proposed. Our study highlights the importance of integrating molecular data with field observations to better understand the reproductive biology and nest

  1. Epidemiological investigations in regard to porcine reproductive and respiratory syndrome (PRRS) in Quebec, Canada. Part 2: prevalence and risk factors in breeding sites.

    PubMed

    Lambert, Marie-Ève; Arsenault, Julie; Poljak, Zvonimir; D'Allaire, Sylvie

    2012-04-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) is a major threat for swine industry and understanding factors involved in its epidemiology is undoubtedly essential for disease control. As a part of a larger project, a cross-sectional study was performed on breeding sites in a moderate density area of swine production in Quebec to estimate the prevalence of PRRSV infected sites and to evaluate if characteristics of sites and biosecurity practices, either as specific measures or as a global score, were associated with PRRSV status. A questionnaire and diagnostic procedures were performed on 54 breeding sites between September 2006 and August 2008. A biosecurity score that had been previously computed using two-step clustering procedure was used, classifying breeding sites into two biosecurity patterns (high vs. low) according to 21 specific biosecurity measures. The apparent prevalence of PRRSV infected sites was 74.0% (95% CI, 60.3-85.0). Univariable and multivariable logistic regression models with robust standard errors adjusting for potential clustering of sites due to same ownership were computed. In a first multivariable model evaluating characteristics of sites and specific biosecurity variables, four main effects were significantly associated (P<0.05) with PRRSV positive status: large pig inventory (OR: 10.7), proximity to closest pig site (OR: 7.3), absence of shower (OR: 8.7) and free access to the main entrance of the site by the rendering truck (OR: 7.0). In a second multivariable model including a global biosecurity score as a surrogate for a specific pattern of biosecurity measures, this score was not retained in the final model. The adjusted population attributable fractions were 16% for the proximity to closest pig site variable, 27% for the absence of shower variable, and 10% for the free access to main entrance of the site by the rendering truck. These two latter biosecurity measures, manageable directly on the site, should be

  2. Aedes aegypti (Diptera: Culicidae) in Mauritania: First Report on the Presence of the Arbovirus Mosquito Vector in Nouakchott.

    PubMed

    Mint Lekweiry, Khadijetou; Ould Ahmedou Salem, Mohamed Salem; Ould Brahim, Khyarhoum; Ould Lemrabott, Mohamed Aly; Brengues, Cécile; Faye, Ousmane; Simard, Frédéric; Ould Mohamed Salem Boukhary, Ali

    2015-07-01

    Aedes aegypti L. (Diptera: Culicidae) is a major vector of yellow fever, dengue, and chikungunya viruses throughout tropical and subtropical areas of the world. Although the southernmost part of Mauritania along the Senegal river has long been recognized at risk of yellow fever transmission, Aedes spp. mosquitoes had never been reported northwards in Mauritania. Here, we report the first observation of Aedes aegypti aegypti (L.) and Aedes (Ochlerotatus) caspius (Pallas, 1771) in the capital city, Nouakchott. We describe the development sites in which larvae of the two species were found, drawing attention to the risk for emergence of arbovirus transmission in the city. PMID:26335483

  3. Combining Site Occupancy, Breeding Population Sizes and Reproductive Success to Calculate Time-Averaged Reproductive Output of Different Habitat Types: An Application to Tricolored Blackbirds

    PubMed Central

    Holyoak, Marcel; Meese, Robert J.; Graves, Emily E.

    2014-01-01

    In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005–2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method

  4. Combining site occupancy, breeding population sizes and reproductive success to calculate time-averaged reproductive output of different habitat types: an application to Tricolored Blackbirds.

    PubMed

    Holyoak, Marcel; Meese, Robert J; Graves, Emily E

    2014-01-01

    In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005-2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method we

  5. Effective autodissemination of pyriproxyfen to breeding sites by the exophilic malaria vector Anopheles arabiensis in semi-field settings in Tanzania

    PubMed Central

    2014-01-01

    Background Malaria vector control strategies that target adult female mosquitoes are challenged by the emergence of insecticide resistance and behavioural resilience. Conventional larviciding is restricted by high operational costs and inadequate knowledge of mosquito-breeding habitats in rural settings that might be overcome by the juvenile hormone analogue, Pyriproxyfen (PPF). This study assessed the potential for Anopheles arabiensis to pick up and transfer lethal doses of PPF from contamination sites to their breeding habitats (i.e. autodissemination of PPF). Methods A semi-field system (SFS) with four identical separate chambers was used to evaluate PPF-treated clay pots for delivering PPF to resting adult female mosquitoes for subsequent autodissemination to artificial breeding habitats within the chambers. In each chamber, a tethered cow provided blood meals to laboratory-reared, unfed female An. arabiensis released in the SFS. In PPF-treated chambers, clay pot linings were dusted with 0.2 – 0.3 g AI PPF per pot. Pupae were removed from the artificial habitats daily, and emergence rates calculated. Impact of PPF on emergence was determined by comparing treatment with an appropriate control group. Results Mean (95% CI) adult emergence rates were (0.21 ± 0.299) and (0.95 ± 0.39) from PPF-treated and controls respectively (p < 0.0001). Laboratory bioassay of water samples from artificial habitats in these experiments resulted in significantly lower emergence rates in treated chambers (0.16 ± 0.23) compared to controls 0.97 ± 0.05) (p < 0.0001). In experiments where no mosquitoes introduced, there were no significant differences between control and treatment, indicating that transfer of PPF to breeding sites only occurred when mosquitoes were present; i.e. that autodissemination had occurred. Treatment of a single clay pot reduced adult emergence in six habitats to (0.34 ± 0.13) compared to (0.98 ± 0.02) in the controls

  6. History of domestication and spread of Aedes aegypti - A Review

    PubMed Central

    Powell, Jeffrey R; Tabachnick, Walter J

    2013-01-01

    The adaptation of insect vectors of human diseases to breed in human habitats (domestication) is one of the most important phenomena in medical entomology. Considerable data are available on the vector mosquito Aedes aegypti in this regard and here we integrate the available information including genetics, behaviour, morphology, ecology and biogeography of the mosquito, with human history. We emphasise the tremendous amount of variation possessed by Ae. aegypti for virtually all traits considered. Typological thinking needs to be abandoned to reach a realistic and comprehensive understanding of this important vector of yellow fever, dengue and Chikungunya. PMID:24473798

  7. Comparison of infusions of commercially available garden products for collection of container-breeding mosquitoes.

    PubMed

    Burkett-Cadena, Nathan D; Mullen, Gary R

    2008-06-01

    In 2004, gravid-trap infusions made from commercially available garden products were compared in field assays to determine their attractiveness to ovipositing female mosquitoes. Experiments were conducted simultaneously at a residential site and at an auto salvage yard in Lee County, AL, each site having an abundance of container-breeding mosquitoes. Several infusion types were initially screened, from which the following 4 infusions were selected to be compared using gravid traps for their attractiveness to mosquitoes under field conditions: oak leaves, pine straw, red (dyed) hardwood mulch, and composted manure. Culex quinquefasciatus was the only species collected in greater numbers with gravid traps than with light traps, and the difference was more than 5-fold at both study sites. Gravid traps collected (mean +/- SD) 3.1 +/- 4.3 and 6.9 +/- 11.5 Cx. quinquefasciatus females at the residential and auto salvage sites, respectively. The response of Cx. quinquefasciatus females to infusions tested was variable, and no single infusion was consistently more attractive throughout the experiment. Gravid traps collected 1.7 +/- 1.9 and 4.7 +/- 4.4 Aedes albopictus females, 0.3 +/- 1.4 and 0.5 +/- 1.3 Cx. nigripalpus females, and 0.3 +/- 0.9 and 0.2 +/- 0.8 Cx. restuans females at the residential and auto salvage sites, respectively. Roughly 5-, 20- and 10-fold the numbers of females of Aedes albopictus, Cx. nigripalpus, and Cx. restuans were collected by light traps than by gravid traps at both sites. Aedes albopictus females did not demonstrate a preference for any of the infusions tested. Significant difference among infusions for Cx. restuans and Cx. nigripalpus were detected on just 1 trap-night. On this occasion, traps with red (dyed) hardwood mulch collected significantly more females of Cx. restuans and Cx. nigripalpus than did traps with other infusions. This work indicates that gravid traps are effective tools for collecting Cx. quinquefasciatus females, and a

  8. Apricot Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apricot orchard area and fruit production are increasing worldwide. Breeding programs engage in apricot development to provide new varieties to meet needs of producers and consumers. Over the last 20 years, breeders have used new techniques to assist in variety development and to increase breeding...

  9. La Crosse Encephalitis Virus Infection in Field-Collected Aedes albopictus, Aedes japonicus, and Aedes triseriatus in Tennessee.

    PubMed

    Westby, Katie M; Fritzen, Charissa; Paulsen, Dave; Poindexter, Stephanie; Moncayo, Abelardo C

    2015-09-01

    La Crosse virus (LACV) is a mosquito-borne virus and a major cause of pediatric encephalitis in the USA. La Crosse virus emerged in Tennessee and other states in the Appalachian region in 1997. We investigated LACV infection rates and seasonal abundances of the native mosquito vector, Aedes triseriatus, and 2 recently introduced mosquito species, Ae. albopictus and Ae. japonicus, in an emerging disease focus in Tennessee. Mosquitoes were collected using multiple trapping methods specific for Aedes mosquitoes at recent human case sites. Mosquito pools were tested via reverse transcriptase-polymerase chain reaction (RT-PCR) of the S segment to detect multiple Bunyamwera and California serogroup viruses, including LACV, as well as real-time RT-PCR of the M segment. A total of 54 mosquito pools were positive, including wild-caught adult females and laboratory-reared adults, demonstrating transovarial transmission in all 3 species. Maximum likelihood estimates (per 1,000 mosquitoes) were 2.72 for Ae. triseriatus, 3.01 for Ae. albopictus, and 0.63 for Ae. japonicus. We conclude that Ae. triseriatus and Ae. albopictus are important LACV vectors and that Ae. japonicus also may be involved in virus maintenance and transmission. PMID:26375904

  10. Development and evaluation of a novel contamination device that targets multiple life-stages of Aedes aegypti

    PubMed Central

    2014-01-01

    Background The increasing global threat of Dengue demands new and easily applicable vector control methods. Ovitraps provide a low-tech and inexpensive means to combat Dengue vectors. Here we describe the development and optimization process of a novel contamination device that targets multiple life-stages of the Aedes aegypti mosquito. Special focus is directed to the diverse array of control agents deployed in this trap, covering adulticidal, larvicidal and autodissemination impacts. Methods Different trap prototypes and their parts are described, including a floater to contaminate alighting gravid mosquitoes. The attractiveness of the trap, different odor lures and floater design were studied using fluorescent powder adhering to mosquito legs and via choice tests. We demonstrate the mosquitocidal impacts of the control agents: a combination of the larvicide pyriproxyfen and the adulticidal fungus Beauveria bassiana. The impact of pyriproxyfen was determined in free-flight dissemination experiments. The effect on larval development inside the trap and in surrounding breeding sites was measured, as well as survival impacts on recaptured adults. Results The developmental process resulted in a design that consists of a black 3 Liter water-filled container with a ring-shaped floater supporting vertically placed gauze dusted with the control agents. On average, 90% of the mosquitoes in the fluorescence experiments made contact with the gauze on the floater. Studies on attractants indicated that a yeast-containing tablet was the most attractive odor lure. Furthermore, the fungus Beauveria bassiana was able to significantly increase mortality of the free-flying adults compared to controls. Dissemination of pyriproxyfen led to >90% larval mortality in alternative breeding sites and 100% larval mortality in the trap itself, against a control mortality of around 5%. Conclusion This ovitrap is a promising new tool in the battle against Dengue. It has proven to be attractive

  11. The “Auto-Dissemination” Approach: A Novel Concept to Fight Aedes albopictus in Urban Areas

    PubMed Central

    Caputo, Beniamino; Ienco, Annamaria; Cianci, Daniela; Pombi, Marco; Petrarca, Vincenzo; Baseggio, Alberto; Devine, Gregor J.; della Torre, Alessandra

    2012-01-01

    Background The main constraint to the fight against container-breeding mosquito vectors of human arboviruses is the difficulty in targeting the multiplicity of larval sources, mostly represented by small man-made water containers. The aim of this work is to assess the feasibility of the “auto-dissemination” approach, already tested for Aedes aegypti, as a possible alternative to traditional, inefficient control tools, against Ae. albopictus in urban areas. The approach is based on the possibility that wild adult females, exposed to artificial resting sites contaminated with pyriproxyfen, can disseminate this juvenile hormone analogue to larval habitats, thus interfering with adult emergence. Methodology We carried out four field experiments in two areas of Rome that are typically highly infested with Ae. albopictus, i.e. the main cemetery and a small green area within a highly urbanised neighbourhood. In each area we used 10 pyriproxyfen “dissemination” stations, 10 “sentinel” sites and 10 covered, control sites. The sentinel and control sites each contained 25 Ae. albopictus larvae. These were monitored for development and adult emergence. Principal Findings When a 5% pyriproxyfen powder was used to contaminate the dissemination sites, we observed significantly higher mortality at the pupal stage in the sentinel sites (50–70%) than in the controls (<2%), showing that pyriproxyfen was transferred by mosquitoes into sentinel sites and that it had a lethal effect. Conclusions The results support the potential feasibility of the auto-dissemination approach to control Ae. albopictus in urban areas. Further studies will be carried out to optimize the method and provide an effective tool to reduce the biting nuisance caused by this aggressive species and the transmission risk of diseases such as Dengue and Chikungunya. These arboviruses pose an increasing threat in Europe as Ae. albopictus expands its range. PMID:22953015

  12. Diversity of containers and buildings infested with Aedes aegypti in Puerto Iguazú, Argentina.

    PubMed

    Costa, Federico; Fattore, Gladys; Abril, Marcelo

    2012-09-01

    Aedes aegypti is the main domestic vector of the dengue virus. Control measures to prevent dengue transmission focus on the treatment and elimination of this vector's oviposition sites. There is limited biological information on Ae. aegypti in Argentina. The aim of this study was to characterize Ae. aegypti oviposition sites in the city of Puerto Iguazú, Argentina. We surveyed an area covering nine neighborhoods in 2005. We identified 191 premises as positive for Ae. aegypti, giving a general house index of 9.6%. Premises classified as residential and vacant lots presented the highest number of infested premises, with 9% and 22% respectively. The total number of surveyed containers was 29,600. The overall container index (CI) was 1.1. The most frequently infested containers were water tanks (CI = 37). These preliminary results suggest that vacant lots and water tanks provide suitable breeding areas and environmental conditions, improving the chances of Ae. aegypti survival in Puerto Iguazú. PMID:23033195

  13. Agricultural land use and human presence around breeding sites increase stress-hormone levels and decrease body mass in barn owl nestlings.

    PubMed

    Almasi, Bettina; Béziers, Paul; Roulin, Alexandre; Jenni, Lukas

    2015-09-01

    Human activities can have a suite of positive and negative effects on animals and thus can affect various life history parameters. Human presence and agricultural practice can be perceived as stressors to which animals react with the secretion of glucocorticoids. The acute short-term secretion of glucocorticoids is considered beneficial and helps an animal to redirect energy and behaviour to cope with a critical situation. However, a long-term increase of glucocorticoids can impair e.g. growth and immune functions. We investigated how nestling barn owls (Tyto alba) are affected by the surrounding landscape and by human activities around their nest sites. We studied these effects on two response levels: (a) the physiological level of the hypothalamus-pituitary-adrenal axis, represented by baseline concentrations of corticosterone and the concentration attained by a standardized stressor; (b) fitness parameters: growth of the nestlings and breeding performance. Nestlings growing up in intensively cultivated areas showed increased baseline corticosterone levels late in the season and had an increased corticosterone release after a stressful event, while their body mass was decreased. Nestlings experiencing frequent anthropogenic disturbance had elevated baseline corticosterone levels, an increased corticosterone stress response and a lower body mass. Finally, breeding performance was better in structurally more diverse landscapes. In conclusion, anthropogenic disturbance affects offspring quality rather than quantity, whereas agricultural practices affect both life history traits. PMID:25903390

  14. Tracking a northern fulmar from a Scottish nesting site to the Charlie-Gibbs Fracture Zone: Evidence of linkage between coastal breeding seabirds and Mid-Atlantic Ridge feeding sites

    NASA Astrophysics Data System (ADS)

    Edwards, Ewan W. J.; Quinn, Lucy R.; Wakefield, Ewan D.; Miller, Peter I.; Thompson, Paul M.

    2013-12-01

    The seas above mid-ocean ridges are biodiversity hotspots in an otherwise largely oligotrophic environment, but the nature and extent of linkage between these offshore regimes and coastal ecosystems remains uncertain. Using a combination of GPS and geolocation tracking data, we show that a male fulmar, breeding on the Scottish coast, foraged over areas of persistent thermal fronts along the Charlie-Gibbs Fracture Zone (CGFZ) of the Mid-Atlantic Ridge during the incubation period. The bird travelled over 6200 km in 14.9 days. First-passage time analysis identified seven areas of restricted search, four on the shelf and three in the vicinity of the Mid-Atlantic Ridge. Previous studies of incubation foraging trip durations at this site suggest that a trip of this duration is unusual, and further work is required to assess the extent to which different individuals use these offshore resources. Nevertheless, these data highlight the potential importance of high sea areas beyond the limits of national jurisdiction when considering the management and conservation of seabirds breeding in NW Europe, and raises the potential for even greater linkage between the CGFZ and seabirds breeding colonies in other regions.

  15. Genetic control of Aedes mosquitoes.

    PubMed

    Alphey, Luke; McKemey, Andrew; Nimmo, Derric; Neira Oviedo, Marco; Lacroix, Renaud; Matzen, Kelly; Beech, Camilla

    2013-06-01

    Aedes mosquitoes include important vector species such as Aedes aegypti, the major vector of dengue. Genetic control methods are being developed for several of these species, stimulated by an urgent need owing to the poor effectiveness of current methods combined with an increase in chemical pesticide resistance. In this review we discuss the various genetic strategies that have been proposed, their present status, and future prospects. We focus particularly on those methods that are already being tested in the field, including RIDL and Wolbachia-based approaches. PMID:23816508

  16. Genetic control of Aedes mosquitoes

    PubMed Central

    Alphey, Luke; McKemey, Andrew; Nimmo, Derric; Neira Oviedo, Marco; Lacroix, Renaud; Matzen, Kelly; Beech, Camilla

    2013-01-01

    Aedes mosquitoes include important vector species such as Aedes aegypti, the major vector of dengue. Genetic control methods are being developed for several of these species, stimulated by an urgent need owing to the poor effectiveness of current methods combined with an increase in chemical pesticide resistance. In this review we discuss the various genetic strategies that have been proposed, their present status, and future prospects. We focus particularly on those methods that are already being tested in the field, including RIDL and Wolbachia-based approaches. PMID:23816508

  17. Distribution of Aedes mosquitoes in the Kilimanjaro Region of northern Tanzania.

    PubMed

    Hertz, Julian T; Lyaruu, Lucille J; Ooi, Eng Eong; Mosha, Franklin W; Crump, John A

    2016-05-01

    Little is known about the presence and distribution of Aedes mosquitoes in northern Tanzania despite the occurence of viruses transmitted by these mosquitoes such as Chikungunya virus (CHIKV) and Dengue virus (DENV) in the region. Adult and larval mosquitoes were collected from rural and urban settings across a wide range of altitudes in the Kilimanjaro Region using the Mosquito Magnet CO2 Trap for collection of adults and old tires for breeding of larvae. Polymerase chain reaction assays were performed on captured adult mosquitoes to detect the presence of CHIKV and DENV. A total of 2609 Aedes aegypti adult mosquitoes were collected; no other Aedes species larvae were found. Mosquito yields were significantly higher in urban settings than rural settings (26.5 vs. 1.9 mosquitoes per day, p = 0.037). A total of 6570 Ae. aegypti larvae were collected from old tires; no other Aedes species larvae were found. Of the 2609 adult mosquitoes collected, none tested positive for CHIKV or DENV. As far as we are aware, this paper reports for the first time the presence of Ae. aegypti in the Kilimanjaro Region of northern Tanzania. Although CHIKV and DENV were not isolated from any of the collected mosquitoes in this study, the apparent absence of other Aedes species in the area suggests that Ae. aegypti is the primary local vector of these infections. PMID:27376502

  18. Invasion of cemeteries in Florida by Aedes albopictus.

    PubMed

    O'Meara, G F; Gettman, A D; Evans, L F; Scheel, F D

    1992-03-01

    Aedes albopictus has been found in 53 of the 67 Florida counties. The initial discoveries in 11 of these counties were made in cemeteries. At several locations, Ae. albopictus became well-established in cemeteries before appearing in nearby accumulations of waste tires. The recycling of plastic floral baskets may be aiding the spread of Ae. albopictus. Mosquitoes were commonly found in all types of flower-holding containers in cemeteries, except bronze vases. In the laboratory, most Aedes aegypti eggs laid in bronze vases hatched, but larvae subsequently died. The spread of Ae. albopictus in cemeteries seems to occur at the expense of Ae. aegypti populations. At one cemetery immature Ae. albopictus and Ae. aegypti were found in about 70% of the Aedes-positive containers at the start of a monitoring program. In subsequent collections from this site, Ae. albopictus was found in nearly all Aedes-positive containers, whereas there was a progressive decrease in containers with Ae. aegypti. This trend did not appear to be the result of any seasonal pattern because in a nearby cemetery where Ae. albopictus was absent, Ae. aegypti did not show a similar decline. Limiting flower-holding containers to those with drain holes or to bronze vases would greatly limit mosquito production. PMID:1583479

  19. Changing Domesticity of Aedes aegypti in Northern Peninsular Malaysia: Reproductive Consequences and Potential Epidemiological Implications

    PubMed Central

    Saifur, Rahman G. M.; Dieng, Hamady; Hassan, Ahmad Abu; Salmah, Md Rawi Che; Satho, Tomomitsu; Miake, Fumio; Hamdan, Ahmad

    2012-01-01

    Background The domestic dengue vector Aedes aegypti mosquitoes breed in indoor containers. However, in northern peninsular Malaysia, they show equal preference for breeding in both indoor and outdoor habitats. To evaluate the epidemiological implications of this peridomestic adaptation, we examined whether Ae. aegypti exhibits decreased survival, gonotrophic activity, and fecundity due to lack of host availability and the changing breeding behavior. Methodology/Principal Findings This yearlong field surveillance identified Ae. aegypti breeding in outdoor containers on an enormous scale. Through a sequence of experiments incorporating outdoors and indoors adapting as well as adapted populations, we observed that indoors provided better environment for the survival of Ae. aegypti and the observed death patterns could be explained on the basis of a difference in body size. The duration of gonotrophic period was much shorter in large-bodied females. Fecundity tended to be greater in indoor acclimated females. We also found increased tendency to multiple feeding in outdoors adapted females, which were smaller in size compared to their outdoors breeding counterparts. Conclusion/Significance The data presented here suggest that acclimatization of Ae. aegypti to the outdoor environment may not decrease its lifespan or gonotrophic activity but rather increase breeding opportunities (increased number of discarded containers outdoors), the rate of larval development, but small body sizes at emergence. Size is likely to be correlated with disease transmission. In general, small size in Aedes females will favor increased blood-feeding frequency resulting in higher population sizes and disease occurrence. PMID:22363516

  20. Field evaluation of three botanical repellents against Psorophora ferox, Aedes atlanticus, and Aedes mitchellae.

    PubMed

    Qualls, Whitney A; Xue, Rui-De

    2009-09-01

    Three botanical natural repellents, Swamp Buddy Bug Chaser (AI 12% plant-based essential oils), All Sport (AI plant-based essential oils, benzophenone-3, octinoxate, and octisalate), and Geraniol (AI 25% geraniol oil and lemongrass extract) were evaluated at a field site in Elkton, Florida, to determine the protection time provided against Psorophora ferox, Aedes atlanticus, and Ae. mitchellae. These three products provided different protection times against biting mosquitoes. Geraniol provided the longest protection time from mosquito bites (4 h), followed by All Sport (1.5 h) and Swamp Buddy Bug Chaser (1 h). This study provides the first information about botanical insect repellents against these floodwater mosquito species. PMID:19852232

  1. Microevolution of Aedes aegypti.

    PubMed

    Louise, Caroline; Vidal, Paloma Oliveira; Suesdek, Lincoln

    2015-01-01

    Scientific research into the epidemiology of dengue frequently focuses on the microevolution and dispersion of the mosquito Aedes aegypti. One of the world's largest urban agglomerations infested by Ae. aegypti is the Brazilian megalopolis of Sao Paulo, where >26,900 cases of dengue were reported until June 2015. Unfortunately, the dynamics of the genetic variability of Ae. aegypti in the Sao Paulo area have not been well studied. To reduce this knowledge gap, we assessed the morphogenetic variability of a population of Ae. aegypti from a densely urbanised neighbourhood of Sao Paulo. We tested if allelic patterns could vary over a short term and if wing shape could be a predictor of the genetic variation. Over a period of 14 months, we examined the variation of genetic (microsatellites loci) and morphological (wing geometry) markers in Ae. aegypti. Polymorphisms were detected, as revealed by the variability of 20 microsatellite loci (115 alleles combined; overall Fst = 0.0358) and 18 wing landmarks (quantitative estimator Qst = 0.4732). These levels of polymorphism are higher than typically expected to an exotic species. Allelic frequencies of the loci changed over time and temporal variation in the wing shape was even more pronounced, permitting high reclassification levels of chronological samples. In spite of the fact that both markers underwent temporal variation, no correlation was detected between their dynamics. We concluded that microevolution was detected despite the short observational period, but the intensities of change of the markers were discrepant. Wing shape failed from predicting allelic temporal variation. Possibly, natural selection (Qst>Fst) or variance of expressivity of wing phenotype are involved in this discrepancy. Other possibly influential factors on microevolution of Ae. aegypti are worth searching. Additionally, the implications of the rapid evolution and high polymorphism of this mosquito vector on the efficacy of control methods have

  2. Microevolution of Aedes aegypti

    PubMed Central

    Louise, Caroline; Vidal, Paloma Oliveira; Suesdek, Lincoln

    2015-01-01

    Scientific research into the epidemiology of dengue frequently focuses on the microevolution and dispersion of the mosquito Aedes aegypti. One of the world’s largest urban agglomerations infested by Ae. aegypti is the Brazilian megalopolis of Sao Paulo, where >26,900 cases of dengue were reported until June 2015. Unfortunately, the dynamics of the genetic variability of Ae. aegypti in the Sao Paulo area have not been well studied. To reduce this knowledge gap, we assessed the morphogenetic variability of a population of Ae. aegypti from a densely urbanised neighbourhood of Sao Paulo. We tested if allelic patterns could vary over a short term and if wing shape could be a predictor of the genetic variation. Over a period of 14 months, we examined the variation of genetic (microsatellites loci) and morphological (wing geometry) markers in Ae. aegypti. Polymorphisms were detected, as revealed by the variability of 20 microsatellite loci (115 alleles combined; overall Fst = 0.0358) and 18 wing landmarks (quantitative estimator Qst = 0.4732). These levels of polymorphism are higher than typically expected to an exotic species. Allelic frequencies of the loci changed over time and temporal variation in the wing shape was even more pronounced, permitting high reclassification levels of chronological samples. In spite of the fact that both markers underwent temporal variation, no correlation was detected between their dynamics. We concluded that microevolution was detected despite the short observational period, but the intensities of change of the markers were discrepant. Wing shape failed from predicting allelic temporal variation. Possibly, natural selection (Qst>Fst) or variance of expressivity of wing phenotype are involved in this discrepancy. Other possibly influential factors on microevolution of Ae. aegypti are worth searching. Additionally, the implications of the rapid evolution and high polymorphism of this mosquito vector on the efficacy of control methods

  3. Effect of Novaluron (Rimon 10 EC) on the mosquitoes Anopheles albimanus, Anopheles pseudopunctipennis, Aedes aegypti, Aedes albopictus and Culex quinquefasciatus from Chiapas, Mexico.

    PubMed

    Arredondo-Jiménez, J I; Valdez-Delgado, K M

    2006-12-01

    Novaluron for non-container breeding and container breeding mosquitoes are 0.166 mg/L and 0.55 mg/L, respectively. Overall, the residual effect was more sustained than that of temephos. The lowest dosage of Novaluron had less of an impact on non-target organisms than did temephos. Small-scale field trials in natural breeding sites treated with Novaluron at 0.6 L/ha eliminated adult emergence of An. albimanus and Cx. coronator for 8 weeks. For phase III studies, Novaluron was tested at the local and village levels, applying the optimum field rate to all natural breeding habitats within 1 km of a pair of neighbouring villages. Village-scale trials of Novaluron at 0.6 L/ha reduced An. albimanus larval populations for at least 8 weeks and, more importantly, sharply reduced the densities of adult host-seeking mosquitoes approaching houses. We conclude that Novaluron is effective and environmentally safer than temephos. PMID:17199749

  4. 1980 breeding bird censuses

    SciTech Connect

    Raynor, G.S.

    1980-09-01

    As part of a program to characterize the plant and animal life of the Laboratory site and the surrounding region, the two breeding bird censuses originated in 1977 were continued in 1980. Coverage was below that of previous years due to illness and travel of some participants, but 11 trips were made to the BNL plot and 8 to the Westhampton plot. Each was censused by separate teams of three volunteer observers. The number of breeding species and number of territorial males on the BNL plot have progressively declined since 1977 but little change has taken place in either number of territories or species composition on the Westhampton plot.

  5. Successful overwintering of Aedes albopictus in Germany.

    PubMed

    Pluskota, Björn; Jöst, Artur; Augsten, Xenia; Stelzner, Lilith; Ferstl, Ina; Becker, Norbert

    2016-08-01

    The Asian tiger mosquito (Aedes albopictus) is of great concern to public health authorities due to its vector competence and rapid spread across the globe. In 2015, two large local breeding populations of Ae. albopictus were discovered in southwest Germany. In spring 2016, we were able to demonstrate the first evidence of a successful overwintering in Germany of this originally tropical mosquito species in different research projects. Particularly noteworthy is the successful hatching of diapause eggs of an Italian strain (Calabria), which overwintered successfully in the field in St. Georgen im Schwarzwald (Baden-Wuerttemberg) at 820 m above sea level. Furthermore, within the scope of a larvae monitoring, the first larvae that hatched in the field were detected on the April 09, 2016 in a rain barrel within the Heidelberg population. Our first results show that self-extinction due to an unsuccessful overwintering cannot be assumed for populations of the Asian tiger mosquito which settled in Germany in previous years. The evidence of a successful overwintering of a large number of diapause eggs and the hatching of the first larvae in field conditions opens the control year against Ae. albopictus in southwest Germany. PMID:27112761

  6. Development and Evaluation of an Attractive Self-Marking Ovitrap to Measure Dispersal and Determine Skip Oviposition in Aedes albopictus (Diptera: Culicidae) Field Populations.

    PubMed

    Davis, Timothy J; Kaufman, Phillip E; Tatem, Andrew J; Hogsette, Jerome A; Kline, Daniel L

    2016-01-01

    Aedes albopictus (Skuse) is a container-breeding species with considerable public health importance. To date, Ae. albopictus oviposition behavior has been assessed in outdoor conditions, but only with laboratory-reared specimens. In outdoor large-cage and field studies, we used an attractive self-marking ovipositional device to assess Ae. albopictus skip oviposition behavior. In field studies, 37 wild Ae. albopictus that visited an attractive self-marking ovisite were subsequently captured at a sticky ovitrap within a 4-d period. Because the average Ae. albopictus gonotrophic period is 4.5-6 d, the wild-caught Ae. albopictus visited at least two oviposition sites within a single gonotrophic period. This provided field-based indirect evidence of skip oviposition. The mean distance traveled (MDT) during the 20-d evaluations ranged from 58 to 78 m. The maximum observed distance traveled was 149 m, which was the outer edge of our trapping ability. As populations of Ae. albopictus increased, the MDT during the 4- and 20-d post-marking period increased significantly. Additional observations of wild-marked and captured Aedes triseriatus (Say) are discussed. PMID:26534725

  7. First record of Aedes (Stegomyia) albopictus in Belgium.

    PubMed

    Schaffner, Francis; Van Bortel, Wim; Coosemans, Marc

    2004-06-01

    The 1st record of Aedes albopictus in Belgium was made in a village in Oost-Vlaanderen Province. Two preimaginal stages were collected on October 31, 2000, in the used tire stock of a recycling company that imports tires from the USA and Japan. The species has reproduced on site, and local environmental conditions make its establishment possible. Anopheles plumbeus was a common companion species found in tires in high densities. PMID:15264633

  8. Physiological breeding.

    PubMed

    Reynolds, Matthew; Langridge, Peter

    2016-06-01

    Physiological breeding crosses parents with different complex but complementary traits to achieve cumulative gene action for yield, while selecting progeny using remote sensing, possibly in combination with genomic selection. Physiological approaches have already demonstrated significant genetic gains in Australia and several developing countries of the International Wheat Improvement Network. The techniques involved (see Graphical Abstract) also provide platforms for research and refinement of breeding methodologies. Recent examples of these include screening genetic resources for novel expression of Calvin cycle enzymes, identification of common genetic bases for heat and drought adaptation, and genetic dissection of trade-offs among yield components. Such information, combined with results from physiological crosses designed to test novel trait combinations, lead to more precise breeding strategies, and feed models of genotype-by-environment interaction to help build new plant types and experimental environments for future climates. PMID:27161822

  9. Spatial Stability of Adult Aedes aegypti Populations

    PubMed Central

    Barrera, Roberto

    2011-01-01

    Vector control programs could be more efficient by identifying the location of highly productive sites of Aedes aegypti. This study explored if the number of female adults of Ae. aegypti in BG-Sentinel traps was clustered and if their spatial distribution changed in time in two neighborhoods in San Juan, Puerto Rico. Traps were uniformly distributed across each neighborhood (130 m from each other), and samples were taken every 3 weeks. Global and local spatial autocorrelations were explored. Spatial stability existed if the rank order of trap captures was kept in time. There was lack of global autocorrelation in both neighborhoods, precluding their stratification for control purposes. Hot and cold spots were identified, revealing the highly focal nature of Ae. aegypti. There was significant spatial stability throughout the study in both locations. The consistency in trap productivity in time could be used to increase the effectiveness of vector and dengue control programs. PMID:22144449

  10. Spatial and temporal country-wide survey of temephos resistance in Brazilian populations of Aedes aegypti.

    PubMed

    Chediak, Mateus; G Pimenta, Fabiano; Coelho, Giovanini E; Braga, Ima A; Lima, José Bento P; Cavalcante, Karina Ribeiro Lj; Sousa, Lindemberg C de; Melo-Santos, Maria Alice V de; Macoris, Maria de Lourdes da G; Araújo, Ana Paula de; Ayres, Constância Flávia J; Andrighetti, Maria Teresa M; Gomes, Ricristhi Gonçalves de A; Campos, Kauara B; Guedes, Raul Narciso C

    2016-05-01

    The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito (Aedes aegypti) in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in Brazil for the last 12 years using discriminating temephos concentrations and the bioassay protocols of the World Health Organization. The mortality results obtained were subjected to spatial analysis for distance interpolation using semi-variance models to generate maps that depict the spread of temephos resistance in Brazil since 1999. The problem has been expanding. Since 2002-2003, approximately half the country has exhibited mosquito populations resistant to temephos. The frequency of temephos resistance and, likely, control failures, which start when the insecticide mortality level drops below 80%, has increased even further since 2004. Few parts of Brazil are able to achieve the target 80% efficacy threshold by 2010/2011, resulting in a significant risk of control failure by temephos in most of the country. The widespread resistance to temephos in Brazilian Ae. aegypti populations greatly compromise effective mosquito control efforts using this insecticide and indicates the urgent need to identify alternative insecticides aided by the preventive elimination of potential mosquito breeding sites. PMID:27143489

  11. Spatial and temporal country-wide survey of temephos resistance in Brazilian populations of Aedes aegypti

    PubMed Central

    Chediak, Mateus; G Pimenta, Fabiano; Coelho, Giovanini E; Braga, Ima A; Lima, José Bento P; Cavalcante, Karina Ribeiro LJ; de Sousa, Lindemberg C; de Melo-Santos, Maria Alice V; Macoris, Maria de Lourdes da G; de Araújo, Ana Paula; Ayres, Constância Flávia J; Andrighetti, Maria Teresa M; Gomes, Ricristhi Gonçalves de A; Campos, Kauara B; Guedes, Raul Narciso C

    2016-01-01

    The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito (Aedes aegypti) in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in Brazil for the last 12 years using discriminating temephos concentrations and the bioassay protocols of the World Health Organization. The mortality results obtained were subjected to spatial analysis for distance interpolation using semi-variance models to generate maps that depict the spread of temephos resistance in Brazil since 1999. The problem has been expanding. Since 2002-2003, approximately half the country has exhibited mosquito populations resistant to temephos. The frequency of temephos resistance and, likely, control failures, which start when the insecticide mortality level drops below 80%, has increased even further since 2004. Few parts of Brazil are able to achieve the target 80% efficacy threshold by 2010/2011, resulting in a significant risk of control failure by temephos in most of the country. The widespread resistance to temephos in Brazilian Ae. aegypti populations greatly compromise effective mosquito control efforts using this insecticide and indicates the urgent need to identify alternative insecticides aided by the preventive elimination of potential mosquito breeding sites. PMID:27143489

  12. Population structure of the mosquito Aedes aegypti (Stegomyia aegypti) in Pakistan.

    PubMed

    Rasheed, S B; Boots, M; Frantz, A C; Butlin, R K

    2013-12-01

    Eleven microsatellite markers were used to determine the genetic population structure and spread of Aedes aegypti (Stegomyia aegypti) (Diptera: Culicidae) in Pakistan using mosquitoes collected from 13 different cities. There is a single genetic cluster of Ae. aegypti in Pakistan with a pattern of isolation by distance within the population. The low level of isolation by distance suggests the long-range passive dispersal of this mosquito, which may be facilitated by the tyre trade in Pakistan. A decrease in genetic diversity from south to north suggests a recent spread of this mosquito from Karachi. A strong negative correlation between genetic distance and the quality of road connections shows that populations in cities connected by better road networks are less differentiated, which suggests the human-aided passive dispersal of Ae. aegypti in Pakistan. Dispersal on a large spatial scale may facilitate the strategy of introducing transgenic Ae. aegypti or intracellular bacteria such as Wolbachia to control the spread of dengue disease in Pakistan, but it also emphasizes the need for simple measures to control container breeding sites. PMID:23662926

  13. Temporal genetic structure of major dengue vector Aedes aegypti from Manaus, Amazonas, Brazil.

    PubMed

    Mendonça, Barbara Alessandra Alves; de Sousa, Adna Cristina Barbosa; de Souza, Anete Pereira; Scarpassa, Vera Margarete

    2014-06-01

    In recent years, high levels of Aedes aegypti infestation and several dengue outbreaks with fatal outcome cases have been reported in Manaus, State of Amazonas, Brazil. This situation made it important to understand the genetic structure and gene flow patterns among the populations of this vector in Manaus, vital pieces of information for their management and development of new control strategies. In this study, we used nine microsatellite loci to examine the effect of seasonality on the genetic structure and gene flow patterns in Ae. aegypti populations from four urban neighborhoods of Manaus, collected during the two main rainy and dry seasons. All loci were polymorphic in the eight samples from the two seasons, with a total of 41 alleles. The genetic structure analyses of the samples from the rainy season revealed genetic homogeneity and extensive gene flow, a result consistent with the abundance of breeding sites for this vector. However, the samples from the dry season were significantly structured, due to a reduction of Ne in two (Praça 14 de Janeiro and Cidade Nova) of the four samples analyzed, and this was the primary factor influencing structure during the dry season. Genetic bottleneck analyses suggested that the Ae. aegypti populations from Manaus are being maintained continuously throughout the year, with seasonal reduction rather than severe bottleneck or extinction, corroborating previous reports. These findings are of extremely great importance for designing new dengue control strategies in Manaus. PMID:24631342

  14. Body size variation of the floodwater mosquito Aedes albifasciatus in Central Argentina.

    PubMed

    Gleiser, R M; Urrutia, J; Gorla, D E

    2000-03-01

    An inverse relationship between larval density and adult body size has been reported for several mosquito species, affecting their survival and vector competence, response to repellents and other factors. Larvae of the floodwater mosquito Aedes (Ochlerotatus) albifasciatus (Macquart) (Diptera: Culicidae) develop quickly in temporary pools, so intraspecific competition (for food or space) might regulate population abundance and affect the size of adult mosquitoes. We investigated the temporal variation of adult female wing-length (an index of body-size) in natural populations of Ae. albifasciatus, using adults collected during each phase of the rainy season. The relationships between adult mosquito abundance, female wing-length, rainfall and temperature were analysed through simple regressions. Skewness of the frequency distribution of wing-lengths showed a strong negative relationship with mean wing-length. The distribution of wing-lengths varied seasonally and was correlated with rainfall 7-15 days previously as the major consequence of breeding site volume. Thus temporal variation of body size in natural populations of Ae. albifasciatus reflected density-dependent changes in the aquatic habitat where immature stages develop, influenced more by rainfall than by temperature or other environmental variables. PMID:10759310

  15. Modelling adult Aedes aegypti and Aedes albopictus survival at different temperatures in laboratory and field settings

    PubMed Central

    2013-01-01

    Background The survival of adult female Aedes mosquitoes is a critical component of their ability to transmit pathogens such as dengue viruses. One of the principal determinants of Aedes survival is temperature, which has been associated with seasonal changes in Aedes populations and limits their geographical distribution. The effects of temperature and other sources of mortality have been studied in the field, often via mark-release-recapture experiments, and under controlled conditions in the laboratory. Survival results differ and reconciling predictions between the two settings has been hindered by variable measurements from different experimental protocols, lack of precision in measuring survival of free-ranging mosquitoes, and uncertainty about the role of age-dependent mortality in the field. Methods Here we apply generalised additive models to data from 351 published adult Ae. aegypti and Ae. albopictus survival experiments in the laboratory to create survival models for each species across their range of viable temperatures. These models are then adjusted to estimate survival at different temperatures in the field using data from 59 Ae. aegypti and Ae. albopictus field survivorship experiments. The uncertainty at each stage of the modelling process is propagated through to provide confidence intervals around our predictions. Results Our results indicate that adult Ae. albopictus has higher survival than Ae. aegypti in the laboratory and field, however, Ae. aegypti can tolerate a wider range of temperatures. A full breakdown of survival by age and temperature is given for both species. The differences between laboratory and field models also give insight into the relative contributions to mortality from temperature, other environmental factors, and senescence and over what ranges these factors can be important. Conclusions Our results support the importance of producing site-specific mosquito survival estimates. By including fluctuating temperature regimes

  16. Flavivirus susceptibility in Aedes aegypti.

    PubMed

    Black, William C; Bennett, Kristine E; Gorrochótegui-Escalante, Norma; Barillas-Mury, Carolina V; Fernández-Salas, Ildefonso; de Lourdes Muñoz, María; Farfán-Alé, José A; Olson, Ken E; Beaty, Barry J

    2002-01-01

    Aedes aegypti is the primary vector of yellow fever (YF) and dengue fever (DF) flaviviruses worldwide. In this review we focus on past and present research on genetic components and environmental factors in Aedes aegypti that appear to control flavivirus transmission. We review genetic relationships among Ae. aegypti populations throughout the world and discuss how variation in vector competence is correlated with overall genetic differences among populations. We describe current research into how genetic and environmental factors jointly affect distribution of vector competence in natural populations. Based on this information, we propose a population genetic model for vector competence and discuss our recent progress in testing this model. We end with a discussion of approaches being taken to identify the genes that may control flavivirus susceptibility in Ae. aegypti. PMID:12234528

  17. Identification of germline transcriptional regulatory elements in Aedes aegypti

    NASA Astrophysics Data System (ADS)

    Akbari, Omar S.; Papathanos, Philippos A.; Sandler, Jeremy E.; Kennedy, Katie; Hay, Bruce A.

    2014-02-01

    The mosquito Aedes aegypti is the principal vector for the yellow fever and dengue viruses, and is also responsible for recent outbreaks of the alphavirus chikungunya. Vector control strategies utilizing engineered gene drive systems are being developed as a means of replacing wild, pathogen transmitting mosquitoes with individuals refractory to disease transmission, or bringing about population suppression. Several of these systems, including Medea, UDMEL, and site-specific nucleases, which can be used to drive genes into populations or bring about population suppression, utilize transcriptional regulatory elements that drive germline-specific expression. Here we report the identification of multiple regulatory elements able to drive gene expression specifically in the female germline, or in the male and female germline, in the mosquito Aedes aegypti. These elements can also be used as tools with which to probe the roles of specific genes in germline function and in the early embryo, through overexpression or RNA interference.

  18. Risk Factors for the Presence of Aedes aegypti and Aedes albopictus in Domestic Water-Holding Containers in Areas Impacted by the Nam Theun 2 Hydroelectric Project, Laos

    PubMed Central

    Hiscox, Alexandra; Kaye, Angela; Vongphayloth, Khamsing; Banks, Ian; Piffer, Michele; Khammanithong, Phasouk; Sananikhom, Pany; Kaul, Surinder; Hill, Nigel; Lindsay, Steven W.; Brey, Paul T.

    2013-01-01

    We assessed risk factors for vectors of dengue and chikungunya viruses near a new hydroelectric project, Nam Theun 2, in Laos. Immature stages of Aedes aegypti were found only in sites within 40 km of the urban provincial capital, but Aedes albopictus was found throughout. Aedes aegypti pupae were most common in water storage jars (odds ratio [OR] = 4.72) and tires (OR = 2.99), and Ae. albopictus pupae were associated with tires in 2009 (OR = 10.87) and drums, tires, and jars in 2010 (drums OR = 3.05; tires OR = 3.45, jars OR = 6.59). Compared with water storage vessels, containers used for hygiene, cooking, and drinking were 80% less likely to harbor Ae. albopictus pupae in 2010 (OR = 0.20), and discarded waste was associated with a 3.64 increased odds of infestation. Vector control efforts should focus on source reduction of water storage containers, particularly concrete jars and tires. PMID:23458958

  19. Population structure of rice varieties used in Turkish rice breeding programs determined using simple-sequence repeat and inter-primer binding site-retrotransposon data.

    PubMed

    Cömertpay, G; Baloch, F S; Derya, M; Andeden, E E; Alsaleh, A; Sürek, H; Özkan, H

    2016-01-01

    Effective breeding programs based on genetic diversity are needed to broaden the genetic basis of rice (Oryza sativa L.) in Turkey. In this study, 81 commercial varieties from seven countries were studied in order to estimate the genomic relationships among them using nine inter-primer binding site (iPBS)-retrotransposon and 17 simple-sequence repeat (SSR) markers. A total of 59 alleles for the SSR markers and 96 bands for the iPBS-retrotransposon markers were detected, with an average of 3.47 and 10.6 per locus, respectively. Each of the varieties could be unequivocally identified by the SSR and iPBS-retrotransposon profiles. The iPBS-retrotransposon- and SSR-based clustering were identical and closely mirrored each other, with a significantly high correlation (r = 0.73). A neighbor-joining cluster based on the combined SSR and iPBS-retrotransposon data divided the rice varieties into three clusters. The population structure was determined using the STRUCTURE software, and three populations (K = 3) were identified among the varieties studied, showing that the diversity harbored by Turkish rice varieties is low. The results indicate that iPBS-retrotransposon markers are a very powerful technique to determine the genetic diversity of rice varieties. PMID:26909982

  20. Globally invasive, withdrawing at home: Aedes albopictus and Aedes japonicus facing the rise of Aedes flavopictus

    NASA Astrophysics Data System (ADS)

    Chaves, Luis Fernando

    2016-04-01

    It has been suggested that climate change may have facilitated the global expansion of invasive disease vectors, since several species have expanded their range as temperatures have warmed. Here, we present results from observations on two major global invasive mosquito vectors (Diptera: Culicidae), Aedes albopictus (Skuse) and Aedes japonicus (Theobald), across the altitudinal range of Mt. Konpira, Nagasaki, Japan, a location within their native range, where Aedes flavopictus Yamada, formerly a rare species, has now become dominant. Spatial abundance patterns of the three species suggest that temperature is an important factor influencing their adult distribution across the altitudinal range of Mt. Konpira. Temporal abundance patterns, by contrast, were associated with rainfall and showed signals of density-dependent regulation in the three species. The spatial and temporal analysis of abundance patterns showed that Ae. flavopictus and Ae. albopictus were negatively associated, even when accounting for differential impacts of weather and other environmental factors in their co-occurrence patterns. Our results highlight a contingency in the expansion of invasive vectors, the potential emergence of changes in their interactions with species in their native communities, and raise the question of whether these changes might be useful to predict the emergence of future invasive vectors.

  1. Development and evaluation of an attractive self-marking ovitrap to measure dispersal and determine skip oviposition in Aedes albopictus(Diptera:Culicidae) field populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aedes albopictus (Skuse) is a container-breeding mosquito of public health importance. Its oviposition behavior has been assessed in outdoor conditions, but only with laboratory-reared specimens. We used an attractive self-marking oviposition device to assess Ae. albopictus skip oviposition behavi...

  2. Contributions of temporal segregation, oviposition choice, and non-additive effects of competitors to invasion success of Aedes japonicus (Diptera: Culicidae) in North America

    PubMed Central

    Murrell, Ebony G.; Noden, Bruce H.; Juliano, Steven A.

    2015-01-01

    The mosquito Aedes japonicus (Diptera: Culicidae) has spread rapidly through North America since its introduction in the 1990s. The mechanisms underlying its establishment in container communities occupied by competitors Aedes triseriatus and Aedes albopictus are unclear. Possibilities include (A) temporal separation of A. japonicus from other Aedes, (B) oviposition avoidance by A. japonicus of sites containing heterospecific Aedes larvae, and (C) non-additive competitive effects in assemblages of multiple Aedes. Containers sampled throughout the summer in an oak-hickory forest near Eureka, MO showed peak abundance for A. japonicus occurring significantly earlier in the season than either of the other Aedes species. Despite this, A. japonicus co-occurred with one other Aedes species in 53 % of samples when present, and co-occurred with both other Aedes in 18 % of samples. In a field oviposition experiment, A. japonicus laid significantly more eggs in forest edge containers than in forest interior containers, but did not avoid containers with low or high densities of larvae of A. triseriatus, A. albopictus, or both, compared to containers without larvae. Interspecific competitive effects (measured as decrease in the index of performance, λ′) of A. triseriatus or A. albopictus alone on A. japonicus larvae were not evident at the densities used, but the effect of both Aedes combined was significantly negative and super-additive of effects of individual interspecific competitors. Thus, neither oviposition avoidance of competitors nor non-additive competitive effects contribute to the invasion success of A. japonicus in North America. Distinct seasonal phenology may reduce competitive interactions with resident Aedes. PMID:26101466

  3. Aedes aegypti (L.) and Aedes albopictus (Skuse) in Singapore City

    PubMed Central

    Chan, K. L.; Ho, B. C.; Chan, Y. C.

    1971-01-01

    Detailed information on the breeding habitats of Ae. aegypti and Ae. albopictus is necessary when planning programmes for their control. The larval habitats of the two species in 10 city areas were counted and classified according to type, frequency of occurrence, location, and function. Of all the breeding habitats recorded 95% were domestic containers. The most common Ae. aegypti breeding habitats were ant traps, earthenware jars, bowls, tanks, tin cans, and drums, ant traps being the most common indoors and earthenware jars the most common out doors. Breeding habitats for Ae. albopictus were commonly found in earthen ware jars, tin cans, ant traps, rubber tires, bowls, and drums; ant traps were the most common indoor habitat and tin cans were most common outdoors. The majority of Ae. aegypti breeding habitats were found indoors, while only half of all the Ae. albopictus breeding habitats were indoors. The indoor and outdoor distribution of breeding habitats of both species was not related to the type of housing in the area. The distribution of the type of breeding habitats, however, was related to the type of housing in the area. Ant traps were common to all areas, but water-storage containers and unused containers were common in slum-house and shop-house areas. Flats, however, had more containers used for keeping plants and flowers. The most common breeding habitats of Ae. aegypti and Ae. albopictus are discussed in relation to the habits of the people. It is concluded that control of the two species will depend largely on a change in such habits, either through public health education or by some form of law enforcement. PMID:5316746

  4. Human Antibody Response to Aedes aegypti Saliva in an Urban Population in Bolivia: A New Biomarker of Exposure to Dengue Vector Bites

    PubMed Central

    Doucoure, Souleymane; Mouchet, François; Cournil, Amandine; Le Goff, Gilbert; Cornelie, Sylvie; Roca, Yelin; Giraldez, Mabel Guerra; Simon, Zaira Barja; Loayza, Roxanna; Misse, Dorothée; Flores, Jorge Vargas; Walter, Annie; Rogier, Christophe; Herve, Jean Pierre; Remoue, Franck

    2012-01-01

    Aedes mosquitoes are important vectors of re-emerging diseases in developing countries, and increasing exposure to Aedes in the developed world is currently a source of concern. Given the limitations of current entomologic methods, there is a need for a new effective way for evaluating Aedes exposure. Our objective was to evaluate specific antibody responses to Aedes aegypti saliva as a biomarker for vector exposure in a dengue-endemic urban area. IgG responses to saliva were strong in young children and steadily waned with age. Specific IgG levels were significantly higher in persons living in sites with higher Ae. aegypti density, as measured by using entomologic parameters. Logistic regression showed a significant correlation between IgG to saliva and exposure level, independently of either age or sex. These results suggest that antibody responses to saliva could be used to monitor human exposure to Aedes bites. PMID:22848099

  5. The Effect of Pyriproxyfen as a “Population Growth Regulator” against Aedes albopictus under Semi-Field Conditions

    PubMed Central

    Ohba, Shin-ya; Ohashi, Kazunori; Pujiyati, Endang; Higa, Yukiko; Kawada, Hitoshi; Mito, Nobuaki; Takagi, Masahiro

    2013-01-01

    An insect growth regulator, pyriproxyfen, has been used for the control of a range of pest insects, including mosquitoes. Pyriproxyfen is effective in inhibiting adult emergence and sterilizing adult females. The Asian tiger mosquito, Aedes albopictus (Skuse), is an important vector of dengue and chikungunya, and is expanding its distribution throughout Europe and the Americas. In the present study, we evaluated the impact of pyriproxyfen-treated bed nets on population growth of Ae. albopictus under semi-field conditions, using 6 small microcosms. We created microcosms containing breeding sites to simulate the natural ecosystem of vector mosquito and installing miniature bed net treated with 350 mg/m2 pyriproxyfen in Experiment I and 35 mg/m2 in Experiment II. For each experiment, we also established microcosms installing untreated polyethylene net (untreated control). The installing nets were provided with artificially torn holes, to simulate damage and allow mosquitoes to penetrate. We released 100 pairs of Ae. albopictus into each microcosm, and allowed them to feed on a mouse under the bed nets at approximately 1-week intervals. In comparison with the untreated control microcosms, the number of eggs laid by the released adults in the pyriproxyfen-treated microcosms was significantly lower in both Experiment I and II. Moreover, egg hatchability was significantly suppressed and pupal mortality was increased. Our results indicate that tarsal contact with pyriproxyfen has been shown to suppress egg production and hatchability in adult females and the auto-dissemination of pyriproxyfen into larval breeding sites by adult mosquitoes, through contact with pyriproxyfen-treated polyethylene bed nets, may suppress the mosquito population density. PMID:23843982

  6. Do fish repel oviposition by Aedes taeniorhynchus?

    PubMed

    Ritchie, S A; Laidlaw-Bell, C

    1994-09-01

    We tested the hypothesis that fish indirectly control mosquitoes by repelling oviposition. Aedes taeniorhynchus oviposition in mangrove forests, natural pools, and excavated pools with different concentrations of fish was compared. Oviposition in adjacent mangrove forests was concentrated in the site with the lowest fish density. In 3 mangrove forests, egg populations from pool banks were significantly (P < 0.001) lower for pools with fish than for fishless pools, with an overall mean +/- SD of 1.6 +/- 5.7 and 20.0 +/- 34.8 eggs/sample, respectively. At one pool, egg densities increased significantly (P < 0.001) from 0.36 to 5.00 eggs/sample after drying killed fish. In excavated pools, oviposition was significantly (P < 0.001) affected by fish. These data indicate that Ae. taeniorhynchus avoids ovipositing in sites with high concentrations of fish and suggest that the response is fish-mediated. This behavior may help to explain the migratory habits and population dynamics of Ae. taeniorhynchus. PMID:7807080

  7. Relative population densities of Aedes albopictus and A. guamensis on Guam

    PubMed Central

    Rozeboom, L. E.; Bridges, J. R.

    1972-01-01

    Aedes guamensis Farner & Bohart is indigenous to Guam but A. albopictus is known to have arrived in 1944. The larval ecology of the two species is very similar; both species breed in tree holes, coconut shells, and other natural and man-made water containers. The purpose of the study was to compare the relative densities of larval populations of the two species with those determined in a survey made in 1948-49. The results suggest that as the population density of A. albopictus increased, that of A. guamensis decreased by as much as about 95% in artificial containers, and by 30% or more in natural breeding habitats. Since there seems to be no environmental factor involved in rendering the breeding places unsuitable for A. guamensis, the reduction in A. guamensis populations may be, in part, the result of competition from A. albopictus. PMID:4538192

  8. Mosquito density forecast from flooding: population dynamics model for Aedes caspius (Pallas).

    PubMed

    Balenghien, T; Carron, A; Sinègre, G; Bicout, D J

    2010-06-01

    Insect population dynamics depend strongly on environmental factors. For floodwater mosquitoes, meteorological conditions are crucial in the rhythm of mosquito abundances. Indeed, rainfall triggers the egg hatching after flooding breeding sites, and temperature controls the duration of the aquatic immature development up to adult emergence. According to this, we have developed a simple mechanistic and tractable model that describes the population dynamics of floodwater mosquitoes as a function only of the most accessible meteorological variables, rainfall and temperature. The model involves three parameters: development duration tdev of the immature aquatic stages, the adult emergence rate function f(t) (characterized by the emergence time scale tau and shaping the profile of adult population abundance), and the depletion rate, alpha, of adult disappearance. The developed model was subsequently applied to fit experimental field data of the dynamics of Aedes caspius (Pallas), the main pest mosquito in southern France. First, it was found that the emergence rate function of adult mosquitoes very well reproduce experimental data of the dynamics of immature development for all sampled temperatures. The estimated values of tdev and tau both exhibit Arrhenius behaviour as a function of temperature. Second, using the meteorological records of rainfall and temperature as inputs, the model correctly fit data from a two-site CO2 trapping survey conducted in 2004 and 2005. The estimated depletion rates (summation of the mortality and the emigration rates) were found to be a concave quadratic function of temperature with a maximum of 0.5 per days at about 22 degrees C. PMID:20170592

  9. Spatial Patterns of High Aedes aegypti Oviposition Activity in Northwestern Argentina

    PubMed Central

    Estallo, Elizabet Lilia; Más, Guillermo; Vergara-Cid, Carolina; Lanfri, Mario Alberto; Ludueña-Almeida, Francisco; Scavuzzo, Carlos Marcelo; Introini, María Virginia; Zaidenberg, Mario; Almirón, Walter Ricardo

    2013-01-01

    Background In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. Methodology Oviposition activity was detected in Orán City (Salta province) using ovitraps, weekly replaced (October 2005–2007). Spatial autocorrelation was measured with Moran’s Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR) sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. Principal Findings Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC = 0.77), obtaining 99% of sensitivity and 75.29% of specificity. Conclusions Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist National Health

  10. Species diversity of mosquito breeding in rubber plantations of Kerala, India.

    PubMed

    Sumodan, P K

    2012-06-01

    During south-west monsoon season, rubber plantations in Kerala have been found to provide ideal conditions for the proliferation of mosquitoes. In a study conducted from June 2005 to September 2010 in Kannur, Wayanad, and Kozhikode districts, 12 species of mosquitoes in 6 genera--Aedes, Armigeres, Culex, Heizmannia, Toxorhynchites, and Verrallina--were found to breed in rain water-filled cups used for collecting rubber latex. The only vector species found was Aedes albopictus, known for its ability to transmit dengue and chikungunya. The combinations of species found associated in the latex cups is also presented. PMID:22894122

  11. Promising new tools to fight Aedes mosquitoes.

    PubMed

    2016-08-01

    Two new tools for suppressing Aedes aegypti mosquito populations have been recommended for pilot testing. Carefully designed trials will be needed to see whether they actually reduce disease as well. Andréia Azevedo Soares reports. PMID:27516632

  12. Aedes mosquito species in western Saudi Arabia.

    PubMed

    Alikhan, Masroor; Al Ghamdi, Khalid; Mahyoub, Jazem Abdullah

    2014-01-01

    The Aedes Meigen (Diptera: Culicidae) mosquito species populations in the western region of Saudi Arabia, especially in and around Jeddah, are increasing, therefore increasing susceptibility of humans to the dengue virus. An extensive survey was carried out for one year, and four species were identified with the help of different pictorial keys available. The identification was based on morphological characteristics of adult female Aedes mosquitoes. PMID:25373216

  13. Influence of Age and Nutritional Status on Flight Performance of the Asian Tiger Mosquito Aedes albopictus (Diptera: Culicidae)

    PubMed Central

    Kaufmann, Christian; Collins, Lauren F.; Brown, Mark R.

    2013-01-01

    The Asian tiger mosquito, Aedes albopictus, is a competent vector for arboviruses and recently was implicated as the vector of the first autochthonous cases of dengue and chikungunya in southern Europe. The objective of this study was to analyze the flight performance of female Ae. albopictus of different ages that were starved, sugar-fed, or sugar-fed and blood-fed, using flight mills. After three days of starvation post emergence, females flew an average distance of 0.7 ± 0.5 km in 1.9 ± 1.5 h during a 16 h trial period, whereas sugar- or sugar- and blood-fed females of this age covered a significantly higher distance of around 3 km with a mean total flight time of around 6 h. The age of females (up to four weeks) had no effect on performance. The average of maximal continuous flight segments of sugar-fed (2.14 ± 0.69 h) and blood-fed (3.17 ± 0.82 h) females was distinctly higher than of starved females (0.38 ± 0.15 h) of which most flyers (83%) performed maximal flight segments that lasted no longer than 0.5 h. Overall, the results for the laboratory monitored flight performance of Ae. albopictus confirm their ability to disperse a few kilometres between breeding site and host. PMID:24404384

  14. Comparison of Mosquito Magnet and Biogents Sentinel Traps for Operational Surveillance of Container-Inhabiting Aedes (Diptera: Culicidae) Species.

    PubMed

    Rochlin, Ilia; Kawalkowski, Margaret; Ninivaggi, Dominick V

    2016-03-01

    Container-inhabiting Aedes are among the most medically important mosquito vectors of diseases. They also impact health and quality of life by their persistent and severe biting. Monitoring of container-inhabiting Aedes species is challenging due to the need for specialized traps and lures. Biogents Sentinel (BGS) trap has become a standard for Aedes albopictus (Skuse) surveillance; however, it has substantial problems with durability, quality of construction, and sample exposure to the elements. The goal of this study was to develop a methodology for collecting medically important container-inhabiting Aedes species in numbers sufficient for population trend analysis, control efficacy studies, and pathogen testing. Mosquito Magnets (MM) baited with BG lure and R-octenol were selected as the most practical alternative to BGS, collecting significantly more Ae. albopictus (32.1 ± 0.7 vs. 5.6 ± 0.1), Aedes japonicus (Theobald) (10.1 ± 0.4 vs. 1.2 ± 0.02), and Aedes triseriatus (Say) (0.9 ± 0.04 vs. 0.04 ± 0.004) females on average per trapping under a variety of weather conditions. MM can be particularly useful for long-term surveillance or when large numbers of specimens are required for pathogen isolation, such as at the sites with suspected dengue or chikungunya transmission. PMID:26520482

  15. Rhamnolipids: solution against Aedes aegypti?

    PubMed Central

    Silva, Vinicius L.; Lovaglio, Roberta B.; Von Zuben, Claudio J.; Contiero, Jonas

    2015-01-01

    Aedes aegypti mosquitoes are the primary transmitters of dengue fever, urban yellow fever, and chikungunya viruses. This mosquito has developed resistance to the insecticides currently used to control their populations. These chemical insecticides are harmful to the environment and can have negative effects on human health. Rhamnolipids are environmentally compatible biological surfactants, but their insecticidal activity has not been extensively studied. The present study evaluated the potential larvicidal, insecticidal, and repellent activities of rhamnolipids against A. aegypti. At concentrations of 800, 900, and 1000 mg/L, rhamnolipids eliminated all mosquito larvae in 18 h and killed 100% of adults at 1000 mg/L. According to the results it may be conclude that rhamnolipids should be applied to control larvae and mosquitos besides present the repellency activity against A. aegypti. PMID:25762986

  16. History of domestication and spread of Aedes aegypti--a review.

    PubMed

    Powell, Jeffrey R; Tabachnick, Walter J

    2013-01-01

    The adaptation of insect vectors of human diseases to breed in human habitats (domestication) is one of the most important phenomena in medical entomology. Considerable data are available on the vector mosquito Aedes aegypti in this regard and here we integrate the available information including genetics, behaviour, morphology, ecology and biogeography of the mosquito, with human history. We emphasise the tremendous amount of variation possessed by Ae. aegypti for virtually all traits considered. Typological thinking needs to be abandoned to reach a realistic and comprehensive understanding of this important vector of yellow fever, dengue and Chikungunya. PMID:24473798

  17. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse)

    PubMed Central

    Erguler, Kamil; Smith-Unna, Stephanie E.; Waldock, Joanna; Proestos, Yiannis; Christophides, George K.; Lelieveld, Jos; Parham, Paul E.

    2016-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations. PMID:26871447

  18. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse).

    PubMed

    Erguler, Kamil; Smith-Unna, Stephanie E; Waldock, Joanna; Proestos, Yiannis; Christophides, George K; Lelieveld, Jos; Parham, Paul E

    2016-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations. PMID:26871447

  19. Undesirable Consequences of Insecticide Resistance following Aedes aegypti Control Activities Due to a Dengue Outbreak

    PubMed Central

    Maciel-de-Freitas, Rafael; Avendanho, Fernando Campos; Santos, Rosangela; Sylvestre, Gabriel; Araújo, Simone Costa; Lima, José Bento Pereira; Martins, Ademir Jesus; Coelho, Giovanini Evelim; Valle, Denise

    2014-01-01

    Background During a dengue outbreak with co-circulation of DENV-1 and -2 in the city of Boa Vista, one patient was diagnosed with DENV-4, a serotype supposed absent from Brazil for almost 30 years. The re-emergence of DENV-4 triggered the intensification of mechanical and chemical Aedes aegypti control activities in order to reduce vector density and avoid DENV-4 dissemination throughout the country. Methods/Principal Findings Vector control activities consisted of (a) source reduction, (b) application of diflubenzuron against larvae and (c) vehicle-mounted space spraying of 2% deltamethrin to eliminate adults. Control activity efficacy was monitored by comparing the infestation levels and the number of eggs collected in ovitraps before and after interventions, performed in 22 Boa Vista districts, covering an area of ∼80% of the city and encompassing 56,837 dwellings. A total of 94,325 containers were eliminated or treated with diflubenzuron. The most frequently positive containers were small miscellaneous receptacles, which corresponded to 59% of all positive breeding sites. Insecticide resistance to deltamethrin was assessed before, during and after interventions by dose-response bioassays adopting WHO-based protocols. The intense use of the pyrethroid increased fourfold the resistance ratio of the local Ae. aegypti population only six months after the beginning of vector control. Curiously, this trend was also observed in the districts in which no deltamethrin was applied by the public health services. On the other hand, changes in the resistance ratio to the organophosphate temephos seemed less influenced by insecticide in Boa Vista. Conclusions Despite the intense effort, mosquito infestation levels were only slightly reduced. Besides, the median number of eggs in ovitraps remained unaltered after control activity intensification. The great and rapid increase in pyrethroid resistance levels of natural Ae. aegypti populations is discussed in the context of

  20. Effects of Metarhizium anisopliae conidia mixed with soil against the eggs of Aedes aegypti.

    PubMed

    Leles, Renan Nunes; D'Alessandro, Walmirton Bezerra; Luz, Christian

    2012-04-01

    The effectiveness of Metarhizium anisopliae IP 46 conidia mixed with soil was tested against Aedes aegypti eggs. Mycelium and new conidia developed first on eggs between 4.8 and 15 days respectively after incubation of fungus-treated soils at 3.3 × 10(3) up to 3.3 × 10(5) conidia/g soil at 25°C and relative humidities close to saturation. After 15-day incubation, 53.3% of the eggs exposed to soil with 3.3 × 10(5) conidia/g showed external development of mycelium and conidia. Fungus-inoculated soils (but not untreated controls) showed some mycelial growth and sporulation apart from the eggs. Some eggs on treated soils hatched; those larvae died and eventually showed fungal development on their bodies. The cumulative relative eclosion of larvae after submersion of treated eggs in water decreased from 52.2% at 3.3 × 10(3) conidia/g to 25.3% at 3.3 × 10(5) conidia/g. These findings clearly showed that A. aegypti eggs can be infected by M. anisopliae when deposited on fungus-contaminated soil. The effectiveness of M. anisopliae against gravid females, larvae, and also eggs of A. aegypti underscored the possible usefulness of this fungus as a mycoinsecticide, whether naturally occurring or artificially applied, in the breeding sites of this mosquito. PMID:21984368

  1. Resting behaviour of Aedes aegypti in Trinidad: with evidence for the re-introduction of indoor residual spraying (IRS) for dengue control

    PubMed Central

    2013-01-01

    Background Historically, Aedes aegypti (L.) mosquitoes were controlled/eradicated by fumigation, residual spraying and the elimination of breeding sites. However, the underlying mechanisms of how these vector populations were managed have never been evaluated. Most studies report that these programs failed due to the emergence of DDT resistance in the 1950s and early 1960s. Therefore, behavioural and physiological factors have never been examined to determine program success or failure. Methods A ten- week study collecting resting and flying mosquitoes from every room in houses using small hand nets and Propokock aspirators in St. Augustine, Trinidad, West Indies was conducted during the rainy season months of October to December 2010. During this period a laboratory study was also conducted to determine how soon after egg laying individual females took a blood-meal. Results The field study showed the major resting sites of Ae. aegypti were bed rooms (81.9%), living rooms (8.7%) and kitchen (6.9%). The laboratory study showed only 10% of females accepted a blood meal immediately after oviposition but the majority, 70% accepted a blood meal 12 hours post oviposition. Conclusions The results provide evidence for the efficacy of indoor residual spraying (IRS) and recommend its re-introduction by targeting the major resting sites of these mosquitoes, especially during dengue fever outbreaks. PMID:24004641

  2. On the analysis of parasite effect for Aedes aegypti and Aedes albopictus population

    NASA Astrophysics Data System (ADS)

    Kallista, Meta; Aldila, Dipo; Nuraini, Nuning; Soewono, Edy

    2014-03-01

    It has been reported in some countries that the population of Aedes aegypti has been significantly reduced by the invasion of Aedes albopictus. There has been a hypothesis explaining this phenomenon of which investigated the influence of parasites pathogenesis to the competition between these two mosquito species in the fields. Ascogregarina taiwanensis and Ascogregarina culicis are known as parasites that infect Aedes albopictus and Aedes aegypti, respectively. Several studies have concluded that Ascogregarina taiwanensis caused high fatality for Aedes aegypti larvae, but Ascogregarina culicis was not pathogenic to Aedes albopictus larvae. Therefore, Ascogregarina taiwanensis may contribute to reduce the number of populations Aedes aegypti in the fields. Inspired by these facts, a mathematical model depicting interaction between parasites and mosquitoes is constructed in this paper. In this model are included six dynamic mosquito compartments, i.e. egg, larvae, infected larvae, adult, infected adult and one dynamic compartment for parasite. Derivation of the existence criteria and the stability analysis of parasite-free equilibrium as well as the basic offspring for the model are presented. Numerical simulations for sensitivity analysis indicating the invasive species for variation parameters are shown.

  3. Rapid identification of Aedes albopictus, Aedes scutellaris, and Aedes aegypti life stages using real-time polymerase chain reaction assays.

    PubMed

    Hill, Lydia A; Davis, Joseph B; Hapgood, George; Whelan, Peter I; Smith, Greg A; Ritchie, Scott A; Cooper, R D; van den Hurk, Andrew F

    2008-12-01

    In 2005, a widespread infestation of Aedes albopictus was discovered in the Torres Strait, the region between northern Australia and New Guinea. To contain this species, an eradication program was implemented in 2006. However, the progress of this program is impeded by the difficulty of morphologically separating Ae. albopictus larvae from the endemic species Aedes scutellaris. In this study, three real-time TaqMan polymerase chain reaction assays that target the ribosomal internal transcribed spacer 1 region were developed to rapidly identify Aedes aegypti, Ae. albopictus, and Ae. scutellaris from northern Australia. Individual eggs, larvae, pupae, and adults, as well as the species composition of mixed pools were accurately identified. The assay method was validated using 703 field-collected specimens from the Torres Strait. PMID:19052295

  4. Interpopulation divergence in competitive interactions of the mosquito Aedes albopictus

    PubMed Central

    Leisnham, P. T.; Lounibos, L.P.; O’Meara, G.F.; Juliano, S.A.

    2009-01-01

    Geographic variation in species interactions can have major effects on distributions. Effects of such variation can be particularly evident for invasive species, in which variation in competitive ability can influence invasive success and impacts. We tested the hypothesis that coexistence or exclusion of the resident mosquito Aedes aegypti results from variation among local populations of the invasive Aedes albopictus in competitive interactions with A. aegypti. We also examined the role of variation in fecundity-size relationship in these competitive interactions. We compared competitive abilities of nine North American populations of A. albopictus, three populations from each of three site types: extinction of A. aegypti following A. albopictus invasion, coexistence following A. albopictus invasion, and A. albopictus allopatric to A. aegypti. Competition among larvae from each A. albopictus population and a single A. aegypti population was tested in laboratory microcosms in a response-surface design. We found interpopulation differences in competitive ability of A. albopictus, but no strong patterns among site types. Extinction sites had steeper average fecundity-size relationships than coexistence sites and allopatric sites, but this did not translate into superior population performance. Certain individual A. albopictus populations had exceptionally large competitive effects on A. aegypti or poor competitive responses to competition from A. aegypti, but competitive effect and response were not correlated. These results suggest that interpopulation variation in the competitive ability of A. albopictus may only partly explain geographic pattern of coexistence with or extinction of A. aegypti. Environmental differences among regions may affect the competitive ability of A. albopictus and influence its invasion success and impact. PMID:19769119

  5. Emperor penguins breeding on iceshelves.

    PubMed

    Fretwell, Peter T; Trathan, Phil N; Wienecke, Barbara; Kooyman, Gerald L

    2014-01-01

    We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land). Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin's reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as "near threatened" in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species. PMID:24416381

  6. Thiosemicarbazones as Aedes aegypti larvicidal.

    PubMed

    da Silva, João Bosco P; Navarro, Daniela Maria do A F; da Silva, Aluizio G; Santos, Geanne K N; Dutra, Kamilla A; Moreira, Diogo Rodrigo; Ramos, Mozart N; Espíndola, José Wanderlan P; de Oliveira, Ana Daura T; Brondani, Dalci José; Leite, Ana Cristina L; Hernandes, Marcelo Zaldini; Pereira, Valéria R A; da Rocha, Lucas F; de Castro, Maria Carolina A B; de Oliveira, Beatriz C; Lan, Que; Merz, Kenneth M

    2015-07-15

    A set of aryl- and phenoxymethyl-(thio)semicarbazones were synthetized, characterized and biologically evaluated against the larvae of Aedes aegypti (A. aegypti), the vector responsible for diseases like Dengue and Yellow Fever. (Q)SAR studies were useful for predicting the activities of the compounds not included to create the QSAR model as well as to predict the features of a new compound with improved activity. Docking studies corroborated experimental evidence of AeSCP-2 as a potential target able to explain the larvicidal properties of its compounds. The trend observed between the in silico Docking scores and the in vitro pLC50 (equals -log LC50, at molar concentration) data indicated that the highest larvicidal compounds, or the compounds with the highest values for pLC50, are usually those with the higher docking scores (i.e., greater in silico affinity for the AeSCP-2 target). Determination of cytotoxicity for these compounds in mammal cells demonstrated that the top larvicide compounds are non-toxic. PMID:26087027

  7. Breeding Horticultural Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant breeding involves selection of plants with combinations of improved traits that are inherited in a predictable manner. Collecting, understanding, and incorporating genetic variation into a horticultural breeding program are critical to success. Clearly defined goals help plant breeders choose ...

  8. Predatory potential of Platynectes sp. (Coleoptera: Dytiscidae) on Aedes albopictus, the vector of dengue/chikungunya in Kerala, India.

    PubMed

    Kumar, N P; Bashir, A; Abidha, S; Sabesan, S; Jambulingam, P

    2014-12-01

    Unused and discarded latex collection containers (LCCs) are the major breeding habitats of Aedes albopictus in the rubber plantations of Kerala, India. Platynectes sp. (Family: Dytiscidae) was observed to invade these habitats during the monsoon season and voraciously devour the larval instars of this major vector species of arbo-viral diseases. Field observations showed a reduction of 70.91% (p = 0.0017) and 100% in Aedes larval density, on the first and four days post release of eight beetles per LCC respectively. In laboratory, a beetle was found to devour 17.75 + 5.0 late larval instars of Ae. albopictus per day. Our findings indicate Platynectes sp. could be a potential bio-control agent against Ae. albopictus, the vector of chikungunya/dengue fevers, in rubber plantations. PMID:25776599

  9. Bacillus thuringiensis var. israelensis Misting for Control of Aedes in Cryptic Ground Containers in North Queensland, Australia

    PubMed Central

    Jacups, Susan P.; Rapley, Luke P.; Johnson, Petrina H.; Benjamin, Seleena; Ritchie, Scott A.

    2013-01-01

    In Australia, dengue is not endemic, although the vector mosquito Aedes aegypti is established in far north Queensland (FNQ). Aedes albopictus has recently invaded the Torres Strait region, but is not established on mainland Australia. To maintain dengue-free, public health departments in FNQ closely monitor introduced dengue infections and confine outbreaks through rigorous vector control responses. To safeguard mainland Australia from Ae. albopictus establishment, pre-emptive strategies are required to reduce its breeding in difficult to access habitats. We compare the residual efficacy of VectoBac WDG, Bacillus thuringiensis var. israelensis (Bti) formulation, as a residual treatment when misted across a typical FNQ bushland using a backpack mister (Stihl SR 420 Mist Blower) at two dose rates up to 16 m. Semi-field condition results, over 16 weeks, indicate that Bti provided high mortality rates (> 80%) sustained for 11 weeks. Mist application penetrated 16 m of dense bushland without efficacy decline over distance. PMID:23358637

  10. Blackberry Breeding and Genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant Breeding Reviews has been published since the early 1980s and each edition presents a thorough review of the state of the are on breeding and genetics of specific crop plant. The extensive chapter on blackberry breeding and genetics is organized as follows: INTRODUCTION (Origin and Speciation...

  11. Chickpea Breeding and Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book presents the current status of chickpea breeding and management by experts from around the world. It thoroughly covers a wide array of subject on chickpea genetics and breeding ranging from cytogenetics, wild relatives and biodiversity, conventional and modern breeding techniques and achi...

  12. Entomological indices of Aedes aegypti at some international airports and seaports of southern India--a report.

    PubMed

    Sharma, S N; Kumar, S; Das, B P; Thomas, T G; Kumar, K; Katyal, R; Gill, K S; Bora, D; Lal, S; Saxena, V K

    2005-09-01

    Entomological surveys were undertaken at some of the international airports/seaports (Bangalore, Calicut, Chennai, Cochin, Thiruvanathapuram and Vishakapatnam) to find out the breeding prevalence of dengue vector mosquito in diverse breeding containers from 1998 to 2004. Three vector indices (House index, Container index and Breateu index) were used to assess the breeding potential at each airport/seaport. International Health Regulations urged national governments to keep all the international airports/seaports and peripheral areas up to 400 meters free from Aedes aegypti mosquitoes. However, surveys revealed high vector indices at all the airports and seaports. Health authorities of airports/seaports need to take cognizance of these facts and develop action plan for appropriate control measures with emphasis on vector surveillance. PMID:17080700

  13. Workbook on Identification of Aedes Aegypti Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable yellow fever control workers to identify the larvae of "Aedes aegypti." The morphological features of mosquito larvae are illustrated in this partially programed text, and the distinguishing features of "A. aegypti" indicated. A glossary is included. (AL)

  14. Population studies of the filarial vector Aedes polynesiensis (Diptera: Culicidae) in two island settings of French Polynesia.

    PubMed

    Hapairai, Limb K; Sang, Michel A Cheong; Sinkins, Steven P; Bossin, Hervé C

    2013-09-01

    A mark-release-recapture study was conducted to estimate the adult population size, migration, and dispersal patterns of male and female Aedes (Stegomyia) polynesiensis (Marks) in a valley of Moorea, a volcanic island, and a motu (islet) on the atoll of Tetiaroa, two settings typical of the Society Islands. Aedes polynesiensis recapture rate was high for females and low for males. The distribution of Aedes species in the valley was heterogeneous. Marked individuals dispersed to most parts of the motu and over great distances in the valley for some females. The study provides insights into the field dynamics of Ae. polynesiensis populations and confirms that more efficient sampling methods are warranted. There was no evidence of active migration between motus on the atoll, suggesting that Tetiaroa is a suitable site for small-scale initial open releases of Wolbachia incompatible insect technique and other sterile insect technique-like suppression or replacement strategies. PMID:24180100

  15. The rationale for attempting to define salt marsh mosquito-breeding areas in Galveston County by remote sensing the associated vegetation

    NASA Technical Reports Server (NTRS)

    Arp, G. K.

    1975-01-01

    The rationale for attempting to define salt marsh mosquito breeding areas in Galveston County was discussed, including a botanical survey of the marsh plant communities, their relationship to flooding, and their exposure to salt water. Particular emphasis is given to Distichlis spicata, a widespread marsh grass. Evidence suggests that breeding areas of Aedes sollicitans are associated with Distichlis and that both species respond to similar ecological conditions in the salt marsh. Aspects of the remote sensing of the Distichlis are considered.

  16. Comparative efficacy of two poeciliid fish in indoor cement tanks against chikungunya vector Aedes aegypti in villages in Karnataka, India

    PubMed Central

    2011-01-01

    Background In 2006, severe outbreaks of Aedes aegypti-transmitted chikungunya occurred in villages in Karnataka, South India. We evaluated the effectiveness of combined information, education and communication (IEC) campaigns using two potential poeciliid larvivorous fish guppy (Poecilia reticulata) and mosquitofish (Gambusia affinis), in indoor cement tanks for Aedes larval control. Methods Trials were conducted in two villages (Domatmari and Srinivaspura) in Tumkur District from March to May 2006 for Poecilia and one village (Balmanda) in Kolar District from July to October 2006 for Gambusia. A survey on knowledge, attitude and practice (KAP) on chikungunya was initially conducted and IEC campaigns were performed before and after fish release in Domatmari (IEC alone, followed by IEC + Poecilia) and Balmanda (IEC + Gambusia). In Srinivaspura, IEC was not conducted. Larval surveys were conducted at the baseline followed by one-week and one-month post-intervention periods. The impact of fish on Aedes larvae and disease was assessed based on baseline and post-intervention observations. Results Only 18% of respondents knew of the role of mosquitoes in fever outbreaks, while almost all (n = 50 each) gained new knowledge from the IEC campaigns. In Domatmari, IEC alone was not effective (OR 0.54; p = 0.067). Indoor cement tanks were the most preferred Ae. aegypti breeding habitat (86.9%), and had a significant impact on Aedes breeding (Breteau Index) in all villages in the one-week period (p < 0.001). In the one-month period, the impact was most sustained in Domatmari (OR 1.58, p < 0.001) then Srinivaspura (OR 0.45, p = 0.063) and Balmanda (OR 0.51, p = 0.067). After fish introductions, chikungunya cases were reduced by 99.87% in Domatmari, 65.48% in Srinivaspura and 68.51% in Balmanda. Conclusions Poecilia exhibited greater survival rates than Gambusia (86.04 vs.16.03%) in cement tanks. Neither IEC nor Poecilia alone was effective against Aedes (p > 0.05). We conclude

  17. Standardized Laboratory Feeding of Larval Aedes japonicus japonicus (Diptera: Culicidae)

    PubMed Central

    Bock, Friederike; Kuch, Ulrich; Pfenninger, Markus; Müller, Ruth

    2015-01-01

    The Asian bush mosquito (Aedes japonicus japonicus, Theobald 1901) is an invasive culicid species which originates in Asia but is nowadays present in northern America and Europe. It is a competent vector for several human disease pathogens. In addition to the public health threat, this invasive species may also be an ecological threat for native container-breeding mosquitoes which share a similar larval habitat. Therefore, it is of importance to gain knowledge on ecological and eco-toxicological features of the Asian bush mosquito. However, optimal laboratory feeding conditions have not yet been established. Standardized feeding methods will be needed in assessing the impact of insecticides or competitional strength of this species. To fill this gap, we performed experiments on food quality and quantity for Ae. j. japonicus larvae. We found out that the commercial fish food TetraMin (Tetra, Melle, Germany) in a dose of 10 mg per larva is the most suitable food tested. We also suggest a protocol with a feeding sequence of seven portions for all larval stages of this species. PMID:26452522

  18. Origin of the Dengue Fever Mosquito, Aedes aegypti, in California

    PubMed Central

    Gloria-Soria, Andrea; Brown, Julia E.; Kramer, Vicki; Hardstone Yoshimizu, Melissa; Powell, Jeffrey R.

    2014-01-01

    Dengue fever is among the most widespread vector-borne infectious diseases. The primary vector of dengue is the Aedes aegypti mosquito. Ae. aegypti is prevalent in the tropics and sub-tropics and is closely associated with human habitats outside its native range of Africa. While long established in the southeastern United States of America where dengue is re-emerging, breeding populations have never been reported from California until the summer of 2013. Using 12 highly variable microsatellite loci and a database of reference populations, we have determined that the likely source of the California introduction is the southeastern United States, ruling out introductions from abroad, from the geographically closer Arizona or northern Mexico populations, or an accidental release from a research laboratory. The power to identify the origin of new introductions of invasive vectors of human disease relies heavily on the availability of a panel of reference populations. Our work demonstrates the importance of generating extensive reference databases of genetically fingerprinted human-disease vector populations to aid public health efforts to prevent the introduction and spread of vector-borne diseases. PMID:25077804

  19. Standardized Laboratory Feeding of Larval Aedes japonicus japonicus (Diptera: Culicidae).

    PubMed

    Bock, Friederike; Kuch, Ulrich; Pfenninger, Markus; Müller, Ruth

    2015-01-01

    The Asian bush mosquito (Aedes japonicus japonicus, Theobald 1901) is an invasive culicid species which originates in Asia but is nowadays present in northern America and Europe. It is a competent vector for several human disease pathogens. In addition to the public health threat, this invasive species may also be an ecological threat for native container-breeding mosquitoes which share a similar larval habitat. Therefore, it is of importance to gain knowledge on ecological and eco-toxicological features of the Asian bush mosquito. However, optimal laboratory feeding conditions have not yet been established. Standardized feeding methods will be needed in assessing the impact of insecticides or competitional strength of this species. To fill this gap, we performed experiments on food quality and quantity for Ae. j. japonicus larvae. We found out that the commercial fish food TetraMin (Tetra, Melle, Germany) in a dose of 10 mg per larva is the most suitable food tested. We also suggest a protocol with a feeding sequence of seven portions for all larval stages of this species. PMID:26452522

  20. Origin of the dengue fever mosquito, Aedes aegypti, in California.

    PubMed

    Gloria-Soria, Andrea; Brown, Julia E; Kramer, Vicki; Hardstone Yoshimizu, Melissa; Powell, Jeffrey R

    2014-01-01

    Dengue fever is among the most widespread vector-borne infectious diseases. The primary vector of dengue is the Aedes aegypti mosquito. Ae. aegypti is prevalent in the tropics and sub-tropics and is closely associated with human habitats outside its native range of Africa. While long established in the southeastern United States of America where dengue is re-emerging, breeding populations have never been reported from California until the summer of 2013. Using 12 highly variable microsatellite loci and a database of reference populations, we have determined that the likely source of the California introduction is the southeastern United States, ruling out introductions from abroad, from the geographically closer Arizona or northern Mexico populations, or an accidental release from a research laboratory. The power to identify the origin of new introductions of invasive vectors of human disease relies heavily on the availability of a panel of reference populations. Our work demonstrates the importance of generating extensive reference databases of genetically fingerprinted human-disease vector populations to aid public health efforts to prevent the introduction and spread of vector-borne diseases. PMID:25077804

  1. Reintroduction of the invasive mosquito species Aedes albopictus in Belgium in July 2013

    PubMed Central

    Boukraa, Slimane; Raharimalala, Fara N.; Zimmer, Jean-Yves; Schaffner, Francis; Bawin, Thomas; Haubruge, Eric; Francis, Frédéric

    2013-01-01

    Since its first report in 2000, the invasive mosquito Aedes albopictus was not found any more during the different entomological inspections performed at its place of introduction in Belgium between 2001 and 2012. In July 2013, one adult male was captured at the same site (a platform of imported used tires located in Vrasene, Oost-Vlaanderen Province), during a monitoring using CO2-baited trap. This finding suggests the reintroduction of the species in Belgium via the used tire trade. PMID:24325893

  2. Reintroduction of the invasive mosquito species Aedes albopictus in Belgium in July 2013.

    PubMed

    Boukraa, Slimane; Raharimalala, Fara N; Zimmer, Jean-Yves; Schaffner, Francis; Bawin, Thomas; Haubruge, Eric; Francis, Frédéric

    2013-01-01

    Since its first report in 2000, the invasive mosquito Aedes albopictus was not found any more during the different entomological inspections performed at its place of introduction in Belgium between 2001 and 2012. In July 2013, one adult male was captured at the same site (a platform of imported used tires located in Vrasene, Oost-Vlaanderen Province), during a monitoring using CO2-baited trap. This finding suggests the reintroduction of the species in Belgium via the used tire trade. PMID:24325893

  3. The invasive mosquito Aedes japonicus in Central Europe.

    PubMed

    Schaffner, F; Kaufmann, C; Hegglin, D; Mathis, A

    2009-12-01

    Complaints about a biting pest led to the recognition of invasive Aedes (Finlaya) japonicus japonicus (Theobald) (Diptera: Culicidae) in Central Europe. Larval collections from cemetery vases revealed a colonized area of approximately 1400 km(2) in northern Switzerland spreading into bordering Germany, suggesting that the mosquito has been established in this region for several years. Within this range, larvae of Ae. japonicus were recovered from more containers than the most common resident culicid species Culex pipiens. Possible introduction sites (used tyre yards and international airports) revealed few or no larvae, and the mode of introduction remains unclear. Given the vector potential of this species for arboviruses, implementation of surveillance and control measures should be considered. PMID:19941611

  4. Temporal genetic stability of Stegomyia aegypti (= Aedes aegypti) populations.

    PubMed

    Gloria-Soria, A; Kellner, D A; Brown, J E; Gonzalez-Acosta, C; Kamgang, B; Lutwama, J; Powell, J R

    2016-06-01

    The mosquito Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) is the primary vector of viruses that cause yellow fever, dengue and Chikungunya fever. In the absence of effective vaccines, the reduction of these diseases relies on vector control strategies. The success of these strategies is tightly linked to the population dynamics of target populations. In the present study, 14 collections from St. aegypti populations separated by periods of 1-13 years were analysed to determine their temporal genetic stability. Although temporal structure is discernible in most populations, the degree of temporal differentiation is dependent on the population and does not obscure the geographic structure of the various populations. The results suggest that performing detailed studies in the years prior to and after population reduction- or modification-based control interventions at each target field site may be useful in assessing the probability of success. PMID:26744174

  5. Distribution, abundance and bionomics of Aedes albopictus in southern Texas.

    PubMed

    Womack, M L

    1993-09-01

    A survey was conducted for Aedes albopictus in southern Texas during the summer of 1992. Thirty-five new country records were added to the distribution of this imported mosquito in Texas. Aedes albopictus was widely distributed throughout the ecological regions in the survey area, but its abundance decreased in counties adjacent to the Rio Grande River. However, these counties had high densities of Aedes aegypti. PMID:8245952

  6. A survey of mosquitoes breeding in used tires in Spain for the detection of imported potential vector species.

    PubMed

    Roiz, D; Eritja, R; Escosa, R; Lucientes, J; Marquès, E; Melero-Alcíbar, R; Ruiz, S; Molina, R

    2007-06-01

    The used tire trade has facilitated the introduction, spread, and establishment of the Asian tiger mosquito, Aedes albopictus, and other mosquito species in several countries of America, Africa, Oceania, and Europe. A strategy for detecting these imported mosquito vectors was developed in Spain during 2003-2004 by EVITAR (multidisciplinary network for the study of viruses transmitted by arthropods and rodents). A survey in 45 locations found no invasive species. Eight autochthonous species of mosquitoes were detected in used tires, including Culex pipiens, Cx. hortensis, Cx. modestus, Anopheles atroparvus, An. claviger, Culiseta longiareolata, Cs. annulata, and Aedes caspius. Dominant species were Cx. pipiens and Cs. longiareolata. Aedes caspius was found in only once, near its natural breeding habitat. Considering the recent discovery of an established population of Ae. albopictus in Catalonia, the increasing commerce of used tires in Spain for recycling, storage, and recapping might greatly contribute to the rapid spread of this species across the Iberian Peninsula. PMID:17633420

  7. Cold Season Mortality Under Natural Conditions and Subsequent Hatching Response of Aedes (Stegomyia) aegypti (Diptera: Culicidae) Eggs in a Subtropical City of Argentina.

    PubMed

    Giménez, Javier Orlando; Fischer, Sylvia; Zalazar, Laura; Stein, Marina

    2015-09-01

    In temperate and subtropical regions, populations of Aedes (Stegomyia) aegypti (L.) survive unfavorable winter conditions in the egg stage. Knowing their survival rates can be of great interest for the health authorities in charge of control activities. In this study, we analyzed the mortality of Ae. aegypti eggs exposed to the cold season as well as their hatching patterns under laboratory conditions in the city of Resistencia, Chaco, Argentina. The mortality rate was 48.6%. No statistically significant differences were observed in the mortality of eggs exposed at different sites. Hatching response differed significantly among the successive postexposure immersions, with the highest proportion of hatched eggs during the first immersion. These results show that the mortality rate of Ae. aegypti eggs exposed to the cold season in a subtropical city of Argentina was higher than those from temperate climate region. The additional mortality of eggs in our study might be related to fungal development (an unexpected event), which was not observed in research in temperate climate. The hatching pattern observed in this study ensures a rapid increase of the population at the beginning of the favorable breeding season, but it also maintains a batch with delayed hatching eggs, posing a risk for the community. PMID:26336247

  8. Assessment of the Impact of Potential Tetracycline Exposure on the Phenotype of Aedes aegypti OX513A: Implications for Field Use

    PubMed Central

    Curtis, Zoe; Matzen, Kelly; Neira Oviedo, Marco; Nimmo, Derric; Gray, Pamela; Winskill, Peter; Locatelli, Marco A. F.; Jardim, Wilson F.; Warner, Simon; Alphey, Luke; Beech, Camilla

    2015-01-01

    Background Aedes aegypti is the primary vector of dengue fever, a viral disease which has an estimated incidence of 390 million infections annually. Conventional vector control methods have been unable to curb the transmission of the disease. We have previously reported a novel method of vector control using a tetracycline repressible self-limiting strain of Ae. aegypti OX513A which has achieved >90% suppression of wild populations. Methodology/Principal Findings We investigated the impact of tetracycline and its analogues on the phenotype of OX513A from the perspective of possible routes and levels of environmental exposure. We determined the minimum concentration of tetracycline and its analogues that will allow an increased survivorship and found these to be greater than the maximum concentration of tetracyclines found in known Ae. aegypti breeding sites and their surrounding areas. Furthermore, we determined that OX513A parents fed tetracycline are unable to pre-load their progeny with sufficient antidote to increase their survivorship. Finally, we studied the changes in concentration of tetracycline in the mass production rearing water of OX513A and the developing insect. Conclusion/Significance Together, these studies demonstrate that potential routes of exposure of OX513A individuals to tetracycline and its analogues in the environment are not expected to increase the survivorship of OX513A. PMID:26270533

  9. Use of remote sensing and geographic information systems to predict locations of Anopheles darlingi-positive breeding sites within the Sibun River in Belize, Central America.

    PubMed

    Achee, Nicole L; Grieco, John P; Masuoka, Penny; Andre, Richard G; Roberts, Donald R; Thomas, James; Briceno, Ireneo; King, Russell; Rejmankova, Eliska

    2006-03-01

    Previous studies have identified several anopheline species integral to the transmission of malaria in Belize. The highly efficient vector, Anopheles darlingi Root, is currently considered the most important. The preferred larval habitat of An. darlingi has been described as floating detritus patches, which are commonly associated with overhanging spiny bamboo, Guadua longifolia (E. Fourn.), along river margins. The objectives of this study were to use remote sensing and geographic information system (GIS) tools to 1) define the landscape features (i.e., river curvature, land cover, and house locations) associated with An. darlingi-positive breeding habitats and 2) determine the association between cleared land cover and the growth of spiny bamboo. A systematic survey was conducted in which all detritus patches of at least 1 m2 were sampled, mapped using GPS, and characterized by cause of habitat lodging. Bamboo stretches growing along the river margins also were mapped. Spatial analyses of satellite imagery found no associations between river characteristics or land cover with positive An. darlingi habitats. In addition, there was no significant difference in cleared versus forested land cover in relation to the presence or absence of bamboo. Results indicate that the average distance from homes to negative habitats was significantly greater than from positive detritus mats. Based on the land cover and river characteristics used, our results do not support the use of remote sensing as a predictive tool to locate specific areas within rivers positive for An. darlingi habitats. PMID:16619625

  10. Population dynamics of Aedes albifasciatus (Diptera: Culicidae) south of Mar Chiquita Lake, central Argentina.

    PubMed

    Gleiser, R M; Gorla, D E; Schelotto, G

    2000-01-01

    Spatial and temporal changes in the abundance of adult female Aedes (Ochlerotatus) albifasciatus (Macquart) were studied using CDC miniature light traps at 7 sites along an 80-km transect parallel to the southern shore of Mar Chiquita Lake (central Argentina) during the rainy seasons between 1994 and 1997. Abundance was greatest and most variable at sites near larval habitats. Rainfall and an index combining rainfall and temperature predicted adult female abundance near larval habitats 7-15 d in advance. The spatial distribution of population abundance seemed to be influenced strongly by local factors, because temporal change at sampling sites located >10 km apart was asynchronous. PMID:15218902

  11. Aedes aegypti (L.) and Aedes albopictus (Skuse) in Singapore City

    PubMed Central

    Chan, K. L.; Chan, Y. C.; Ho, B. C.

    1971-01-01

    There is a current belief stemming from statements made in the literature that Ae. aegypti is displacing Ae. albopictus in a number of cities of South-East Asia and in Calcutta, India. A critical review of these works showed that either the observations were inconclusive or the methods of collection were biased for one or the other species. Extensive surveys of the larval habitats of the two species in Singapore showed that the sharing of breeding habitats was uncommon in both urban and rural areas. In the laboratory, Ae. aegypti took a slightly shorter time to complete its development from egg-hatching to adult emergence. It is concluded that information available at present is insufficient to interpret the Ae. aegypti—Ae. albopictus population balance resulting from interspecific competition in Singapore. The pattern of distribution of the two species is unlikely to be the result of competitive displacement; it is, rather, probable that this pattern results from factors that favour the rapid increase and spread of one species over the other. It is suggested that Ae. aegypti in the city is favoured by rapid and extensive urbanization and by the higher fecundity and shorter life cycle of the species. PMID:5316748

  12. Emperor Penguins Breeding on Iceshelves

    PubMed Central

    Fretwell, Peter T.; Trathan, Phil N.; Wienecke, Barbara; Kooyman, Gerald L.

    2014-01-01

    We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land). Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin’s reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as “near threatened” in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species. PMID:24416381

  13. Larval mosquito habitat utilization and community dynamics of Aedes albopictus and Aedes japonicus (Diptera: Culicidae).

    PubMed

    Bartlett-Healy, Kristen; Unlu, Isik; Obenauer, Peter; Hughes, Tony; Healy, Sean; Crepeau, Taryn; Farajollahi, Ary; Kesavaraju, Banu; Fonseca, Dina; Schoeler, George; Gaugler, Randy; Strickman, Daniel

    2012-07-01

    Aedes albopictus (Skuse) and Ae. japonicus (Theobald) are important container-inhabiting mosquitoes that transmit disease agents, outcompete native species, and continue to expand their range in the United States. Both species deposit eggs in natural and artificial containers and thrive in peridomestic environments. The goal of our study was to examine the types and characteristics of containers that are most productive for these species in the northeastern United States. In total, 306 containers were sampled in urban, suburban, and rural areas of New Jersey. Multiple biotic and abiotic factors were recorded in an attempt to identify variables associated with the productivity of each species. Based on pupal abundance and density of container types, results showed that tires, trash cans, and planter dishes were the most important containers for Ae. albopictus, while planter dishes were the most important containers for Ae. japonicus. Container color (black and gray), material (rubber), and type (tires) were correlated with species presence for Ae. albopictus and Ae. japonicus. These factors may play a role in the selection of oviposition sites by female mosquitoes or in the survival of their progeny. Differences in species composition and abundance were detected between areas classified as urban, suburban, and rural. In urban and suburban areas, Ae. albopictus was more abundant in container habitats than Ae. japonicus; however, Ae. japonicus was more abundant in rural areas, and when water temperatures were below 14 degrees C. Our results suggest many variables can influence the presence of Ae. albopictus and Ae. japonicus in container habitats in northeastern United States. PMID:22897041

  14. Multi-scale habitat selection in highly territorial bird species: Exploring the contribution of nest, territory and landscape levels to site choice in breeding rallids (Aves: Rallidae)

    NASA Astrophysics Data System (ADS)

    Jedlikowski, Jan; Chibowski, Piotr; Karasek, Tomasz; Brambilla, Mattia

    2016-05-01

    Habitat selection often involves choices made at different spatial scales, but the underlying mechanisms are still poorly understood, and studies that investigate the relative importance of individual scales are rare. We investigated the effect of three spatial scales (landscape, territory, nest-site) on the occurrence pattern of little crake Zapornia parva and water rail Rallus aquaticus at 74 ponds in the Masurian Lakeland, Poland. Habitat structure, food abundance and water chemical parameters were measured at nests and random points within landscape plots (from 300-m to 50-m radius), territory (14-m) and nest-site plots (3-m). Regression analyses suggested that the most relevant scale was territory level, followed by landscape, and finally by nest-site for both species. Variation partitioning confirmed this pattern for water rail, but also highlighted the importance of nest-site (the level explaining the highest share of unique variation) for little crake. The most important variables determining the occurrence of both species were water body fragmentation (landscape), vegetation density (territory) and water depth (at territory level for little crake, and at nest-site level for water rail). Finally, for both species multi-scale models including factors from different levels were more parsimonious than single-scale ones, i.e. habitat selection was likely a multi-scale process. The importance of particular spatial scales seemed more related to life-history traits than to the extent of the scales considered. In the case of our study species, the territory level was highly important likely because both rallids have to obtain all the resources they need (nest site, food and mates) in relatively small areas, the multi-purpose territories they defend.

  15. Mosquito Protein Kinase G Phosphorylates Flavivirus NS5 and Alters Flight Behavior in Aedes aegypti and Anopheles gambiae

    PubMed Central

    Keating, Julie A.; Bhattacharya, Dipankar; Rund, Samuel S.C.; Hoover, Spencer; Dasgupta, Ranjit; Lee, Samuel J.; Duffield, Giles E.

    2013-01-01

    Abstract Many arboviral proteins are phosphorylated in infected mammalian cells, but it is unknown if the same phosphorylation events occur when insects are similarly infected. One of the mammalian kinases responsible for phosphorylation, protein kinase G (PKG), has been implicated in the behavior of multiple nonvector insects, but is unstudied in mosquitoes. PKG from Aedes aegypti was cloned, and phosphorylation of specific viral sites was monitored by mass spectrometry from biochemical and cell culture experiments. PKG from Aedes mosquitoes is able to phosphorylate dengue nonstructural protein 5 (NS5) at specific sites in cell culture and cell-free systems and autophosphorylates its own regulatory domain in a cell-free system. Injecting Aedes aegypti and Anopheles gambiae mosquitoes with a pharmacological PKG activator resulted in increased Aedes wing activity during periods of their natural diurnal/crepuscular activity and increased Anopheles nocturnal locomotor/flight activity. Thus, perturbation of the PKG signaling pathway in mosquitoes alters flight behavior. The demonstrated effect of PKG alterations is consistent with a viral PKG substrate triggering increased PKG activity. This increased PKG activity could be the mechanism by which dengue virus increases flight behavior and possibly facilitates transmission. Whether or not PKG is part of the mechanism by which dengue increases flight behavior, this report is the first to show PKG can modulate behavior in hematophagous disease vectors. PMID:23930976

  16. Sexual Reproduction and Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the second edition of Plant Propagation Concepts and Laboratory Exercises, we have combined the first edition chapters 36: Sexual Reproduction in Angiosperms and 37: Breeding Horticultural Plants into the present single chapter Sexual Reproduction and Breeding. These topics are so closely relate...

  17. Blackberry breeding and genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blackberry (Rubus L. subgenus Rubus Watson) improvement has made substantial progress with over 400 cultivars named originating from wild selections to many releases from breeding efforts. Public breeding has been ongoing for over 100 years. The result of these improvements is commercial production ...

  18. Sustainable urban development and human health: septic tank as a major breeding habitat of mosquito vectors of human diseases in south-eastern Nigeria.

    PubMed

    Nwoke, B E; Nduka, F O; Okereke, O M; Ehighibe, O C

    1993-02-01

    Septic tank mosquitoes in Abia State University Okigwe, south-eastern Nigeria were studied using exit traps between November 1988 and April 1989. The results were revealing and striking. Apart from the common septic tank mosquitoes, Culex p. quinquefasciatus, Cu. cinereus and Aedes aegypti, which have been previously commonly found breeding in ammonia and nitrate-rich waters of latrines and septic tanks, the other species, Cu. horridus, Cu. tigripes and Aedes vittatus, have not been commonly reported as colonizing septic tanks in Nigeria. Three out of these six mosquito species observed are vectors of human diseases: Aedes aegypti and Aedes vittatus are vectors of Yellow fever and Cu. p. quinquefasciatus is a potential vector of Bancroftian filariasis and a world-wide vector of various arboviruses. The fact that these mosquito vectors are able to breed in highly polluted waters of septic tanks during the harsh dry months when most surface water bodies are dry is epidemiologically important. The breeding of these mosquito vectors of human diseases around human dwellings indicates an intense man-vector contact creating a high level risk to the crowded urban population. The public health implications of this urbanization/modernization problem and solutions are discussed. PMID:8508215

  19. Breeding colonies of least terns (Sternula antillarum) in northern Sonora, Mexico, 2006-2008

    USGS Publications Warehouse

    Rosemartin, Alyssa; van Riper, Charles, III

    2012-01-01

    We document distribution of breeding least terns (Sternula antillarum) in northern Sonora, Mexico, 2006-2008. We report breeding activity at six sites with active colonies, including three previously undocumented colonies.

  20. Behavioral responses of two dengue virus vectors, Aedes aegypti and Aedes albopictus (Diptera: Culicidae), to DUET TM and its components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ultralow volume (ULV) droplets of DUET TM, prallethrin and sumithrin at a sublethal dose were applied to unfed (non bloodfed) and bloodfed female Aedes aegypti Linn. and Aedes albopictus (Skuse) in a wind tunnel. Control spray droplets only contained inactive ingredients. Individual mosquitoes wer...

  1. Laboratory evaluation of the response of Aedes aegypti and Aedes albopictus uninfected and infected with dengue virus to deet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory studies were conducted to compare the response of Aedes aegypti (L.) and Aedes albopictus (Skuse) adults, uninfected and infected with four serotypes of dengue virus, to a repellent containing 5% deet. The results showed that mosquitoes infected with the four serotypes of dengue respond i...

  2. Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 6--Breeding in empty conditions of rice fields in south-eastern Brazil.

    PubMed

    Forattini, O P; Kakitani, I; Massad, E; Marucci, D

    1994-12-01

    Studies on culicid breeding in empty rice fields were carried out during the cultivation cycle from May to November 1993. This period corresponded to stages 1 and 2, when empty conditions prevailed. Breeding occurred in stage 1 and the first part of stage 2, corresponding respectively to fallow uncultivated and ploughing situations. No breeding was found to take place during the second part of stage 2 when transient floods and harrowing occurred. The predominant species were Aedes scapularis, Culex nigripalpus and Cx. mollis. The Pilosus Group of Culex (Melanoconion) was found at lower densities. Some epidemiological considerations are presented. PMID:7660043

  3. Asymmetric Mating Interference between Two Related Mosquito Species: Aedes (Stegomyia) albopictus and Aedes (Stegomyia) cretinus

    PubMed Central

    Giatropoulos, Athanassios; Papachristos, Dimitrios P.; Koliopoulos, George; Michaelakis, Antonios; Emmanouel, Nickolaos

    2015-01-01

    Aedes (Stegomyia) albopictus (Skuse) and Aedes (Stegomyia) cretinus Edwards are closely related mosquito species with common morphological features and bio-ecological similarities. Recent mosquito surveillance in Athens, Greece, showed that they are sympatric mosquito species, with Ae. Albopictus developing quite higher population densities than Ae. Cretinus. The potential of mating interference between these species was investigated by reciprocal and homologous mating experiments in cages under laboratory conditions. In non-choice interspecific crosses (groups of males and females) females of both species produced sterile eggs. Insemination rate was 58% for Ae. Cretinus females and only 1% for Ae. Albopictus females. Aedes albopictus males were sexually aggressive and inseminated Ae. Cretinus females (31%) in choice experiments, where males of one species had access to mate with females of both species. Whereas, interspecific mating of Ae. Albopictus females with Ae. Cretinus males in the co-occurrence of Ae. Cretinus females was weaker (4%). Aedes cretinus females from non-choice crossing with Ae. Albopictus or Ae. Cretinus males were paired individually with conspecific males. The percentage of fertile Ae. Cretinus females was 17.5% when had encaged before with Ae. Albopictus males, compared to 100% when Ae. Cretinus females were encaged with conspecific males only. Probable ecological consequences of asymmetric mating between these ecologically homologous species in nature are discussed. PMID:26001099

  4. Polymorphisms of Chicken TLR3 and 7 in Different Breeds

    PubMed Central

    Ruan, Wenke; An, Jian; Wu, Yanhua

    2015-01-01

    Toll-like receptors (TLRs) mediate immune responses via the recognition of pathogen-associated molecular patterns (PAMPs), thus playing important roles in host defense. Among the chicken (Ch) TLR family, ChTLR3 and 7 have been shown to recognize viral RNA. In our earlier studies, we have reported polymorphisms of TLR1, 2, 4, 5, 15 and 21. In the present study, we amplified TLR3 and 7 genes from different chicken breeds and analyzed their sequences. We identified 7 amino acid polymorphism sites in ChTLR3 with 6 outer part sites and 1 inner part site, and 4 amino acid polymorphism sites in ChTLR7 with 3 outer part sites and 1 inner part site. These results demonstrate that ChTLR genes are polymorphic among different chicken breeds, suggesting a varied resistance across numerous chicken breeds. This information might help improve chicken health by breeding and vaccination. PMID:25781886

  5. Interspecific Competition between Aedes albopictus and A. sierrensis: Potential for Competitive Displacement in the Western United States

    PubMed Central

    Kesavaraju, Banugopan; Leisnham, Paul T.; Keane, Samantha; Delisi, Nicholas; Pozatti, Rachel

    2014-01-01

    The Asian tiger mosquito, Aedes albopictus, was first detected in North America twenty five years ago. It utilizes water-holding container habitats as immature development sites, and has rapidly spread throughout the eastern United States. Aedes albopictus has occasionally been detected in the western United States, but until recently no established populations of A. albopictus were reported. The western tree-hole mosquito, Aedes sierrensis, is the most common tree-hole mosquito throughout the western United States, and is expected to more frequently encounter A. albopictus. In this study, competition between A. albopictus from the eastern United States and A. sierrensis from the western United States was tested in order to better understand the potential for either competitive displacement of A. sierrensis by A. albopictus or competitive resistance of A. sierrensis to A. albopictus. Varying densities of each species were reared with limited resources in a response surface design. Consistent with a prior study, we found that A. albopictus was clearly a superior larval competitor than A. sierrensis. Aedes sierrensis λ′ (finite rate of increase) decreased with increasing A. albopictus density, but in contrast, A. albopictus λ′ actually increased with increasing A. sierrensis density; a result that was not reflected by individual fitness parameters. These results indicate that A. sierrensis will not be an effective barrier to A. albopictus invasion into tree-holes in the western United States. PMID:24586969

  6. Spatial and Temporal Variation in Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Numbers in the Yogyakarta Area of Java, Indonesia, With Implications for Wolbachia Releases.

    PubMed

    Tantowijoyo, W; Arguni, E; Johnson, P; Budiwati, N; Nurhayati, P I; Fitriana, I; Wardana, S; Ardiansyah, H; Turley, A P; Ryan, P; O'Neill, S L; Hoffmann, A A

    2016-01-01

    of mosquito vector populations, particularly through Wolbachia endosymbionts. The success of these strategies depends on understanding the dynamics of vector populations. In preparation for Wolbachia releases around Yogyakarta, we have studied Aedes populations in five hamlets. Adult monitoring with BioGent- Sentinel (BG-S) traps indicated that hamlet populations had different dynamics across the year; while there was an increase in Aedes aegypti (L.) and Aedes albopictus (Skuse) numbers in the wet season, species abundance remained relatively stable in some hamlets but changed markedly (>2 fold) in others. Local rainfall a month prior to monitoring partly predicted numbers of Ae. aegypti but not Ae. albopictus. Site differences in population size indicated by BG-S traps were also evident in ovitrap data. Egg or larval collections with ovitraps repeated at the same location suggested spatial autocorrelation (<250 m) in the areas of the hamlets where Ae. aegypti numbers were high. Overall, there was a weak negative association (r<0.43) between Ae. aegypti and Ae. albopictus numbers in ovitraps when averaged across collections. Ae. albopictus numbers in ovitraps and BG-S traps were positively correlated with vegetation around areas where traps were placed, while Ae. aegypti were negatively correlated with this feature. These data inform intervention strategies by defining periods when mosquito densities are high, highlighting the importance of local site characteristics on populations, and suggesting relatively weak interactions between Ae. aegypti and Ae. albopictus. They also indicate local areas within hamlets where consistently high mosquito densities may influence Wolbachia invasions and other interventions. PMID:26576934

  7. Aedes aegypti resistance to temephos in Argentina.

    PubMed

    Seccacini, Emilia; Lucia, Alejandro; Zerba, Eduardo; Licastro, Susana; Masuh, Hector

    2008-12-01

    Monitoring of resistance of Aedes aegypti to temephos was implemented in the provinces of Formosa and Misiones, Argentina, as a response to the need to improve the vigilance for the dengue vector in areas of high risk of dengue. Eggs collected in each locality were reared, and susceptibility to temephos was assayed using larval bioassays. A weak decrease in susceptibility of larvae to temephos was observed in Clorinda and Puerto Iguazú, indicating an incipient resistance with a resistance ratio of 3. No control failures have been observed yet, and this program should allow the early detection of a real problem in our country. PMID:19181076

  8. Welfare in horse breeding

    PubMed Central

    Campbell, M. L. H.; Sandøe, P.

    2015-01-01

    Welfare problems related to the way horses are bred, whether by coitus or by the application of artificial reproduction techniques (ARTs), have been given no discrete consideration within the academic literature. This paper reviews the existing knowledge base about welfare issues in horse breeding and identifies areas in which data is lacking. We suggest that all methods of horse breeding are associated with potential welfare problems, but also that the judicious use of ARTs can sometimes help to address those problems. We discuss how negative welfare effects could be identified and limited and how positive welfare effects associated with breeding might be maximised. Further studies are needed to establish an evidence base about how stressful or painful various breeding procedures are for the animals involved, and what the lifetime welfare implications of ARTs are for future animal generations. PMID:25908746

  9. Pyrethroid resistance in Aedes aegypti larvae (Diptera: Culicidae) from Singapore.

    PubMed

    Koou, Sin-Ying; Chong, Chee-Seng; Vythilingam, Indra; Ng, Lee-Ching; Lee, Chow-Yang

    2014-01-01

    We report the first comprehensive insecticide susceptibility status ofAedes aegypti (L.) larvae from Singapore. The study indicated that Ae. aegypti is susceptible to temephos, although resistance (RR50 = 1.29-4.43-fold) couldbe developing. Of high concern is the detection of moderate to high resistance to permethrin (RR50 = 29-47-fold) and etofenprox (RR50 = 14-34-fold). Biolarvicide Bacillus thuringiensis israelensis (Bti) remains effective. The insecticide susceptibility profile of Ae. aegypti larvae was found to be homogenous among the different sites studied across the island city. The addition of synergists piperonyl butoxide, S,S,S,-tributyl phosphorotrithioate, and triphenyl phosphate generally failed to enhance the toxicity of the insecticides investigated, suggesting an insignificant role of metabolic-based resistance, and a possible involvement of target site resistance. Further biochemical investigation of specific metabolic enzyme activities suggested that detoxifying enzymes, mono-oxygenases, esterases, glutathione S-transferases, and altered acetylcholinesterases, generally did not contribute to the resistance observed. This study clearly demonstrated that pyrethroid resistance is widespread among Ae. aegypti population and lowered susceptibility to organophosphates is developing. PMID:24605467

  10. Assisted Breeding in Sugar Beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular insight and methods applied to plant breeding and germplasm enhancement is the goal of assisted breeding, also known as marker assisted breeding, marker assisted selection, molecular plant breeding, or genome-wide selection, among others. The basic idea is that most, if not all, heritable ...

  11. Integrating individual-based indices of contaminant effects. How multiple sublethal effects may ultimately reduce amphibian recruitment from a contaminated breeding site.

    PubMed

    Rowe, C L; Hopkins, W A; Congdon, J D

    2001-11-29

    Habitat contamination can alter numerous biological processes in individual organisms. Examining multiple individual-level responses in an integrative fashion is necessary to understand how individual health or fitness reflects environmental contamination. Here we provide an example of such an integrated perspective based upon recent studies of an amphibian (the bullfrog, Rana catesbeiana ) that experiences several, disparate changes when larval development occurs in a trace element-contaminated habitat. First, we present an overview of studies focused on specific responses of individuals collected from, or transplanted into, a habitat contaminated by coal combustion residues (CCR). These studies have reported morphological, behavioral, and physiological modifications to individuals chronically interacting with sediments in the CCR-contaminated site. Morphological abnormalities in the oral and tail regions in contaminant-exposed individuals influenced other properties such as grazing, growth, and swimming performance. Behavioral changes in swimming activities and responses to stimuli appear to influence predation risk in the contaminant-exposed population. Significant changes in bioenergetics in the contaminated habitat, evident as abnormally high energetic expenditures for survival (maintenance) costs, may ultimately influence production pathways (growth, energy storage) in individuals. We then present a conceptual model to examine how interactions among the affected systems (morphological, behavioral, physiological) may ultimately bring about more severe effects than would be predicted if the responses were considered in isolation. A complex interplay among simultaneously occurring biological changes emerges in which multiple, sublethal effects ultimately can translate into reductions in larval or juvenile survival, and thus reduced recruitment of juveniles into the population. In systems where individuals are exposed to low concentrations of contaminants for

  12. Breeding System of Ruellia succulenta Small (Acanthaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examines the breeding system of Ruellia succulenta (Acanthaceae), an herbaceous perennial found in the pine rockland habitat of southern Florida. Hand pollination treatments were performed on 75 plants, 25 from each of three sites. Treatments applied to test plants included: 1) control ...

  13. First record of Aedes koreicus (Diptera: Culicidae) in Germany.

    PubMed

    Werner, Doreen; Zielke, Dorothee E; Kampen, Helge

    2016-03-01

    Within the framework of a national mosquito monitoring programme, a mosquito specimen collected in mid-2015 in southern Germany was identified as Aedes koreicus, a non-endemic species originating from East Asia. After the Asian bush mosquito Aedes japonicus, which is already established in Germany and widely distributed, and the Asian tiger mosquito Aedes albopictus, which is increasingly often introduced from southern Europe, A. koreicus is the third demonstrated invasive mosquito species in Germany supposed to have significant vector potential for disease agents. PMID:26614356

  14. Estimating superpopulation size and annual probability of breeding for pond-breeding salamanders

    USGS Publications Warehouse

    Kinkead, K.E.; Otis, D.L.

    2007-01-01

    It has long been accepted that amphibians can skip breeding in any given year, and environmental conditions act as a cue for breeding. In this paper, we quantify temporary emigration or nonbreeding probability for mole and spotted salamanders (Ambystoma talpoideum and A. maculatum). We estimated that 70% of mole salamanders may skip breeding during an average rainfall year and 90% may skip during a drought year. Spotted salamanders may be more likely to breed, with only 17% avoiding the breeding pond during an average rainfall year. We illustrate how superpopulations can be estimated using temporary emigration probability estimates. The superpopulation is the total number of salamanders associated with a given breeding pond. Although most salamanders stay within a certain distance of a breeding pond for the majority of their life spans, it is difficult to determine true overall population sizes for a given site if animals are only captured during a brief time frame each year with some animals unavailable for capture at any time during a given year. ?? 2007 by The Herpetologists' League, Inc.

  15. Slipping through the Cracks: Rubber Plantation Is Unsuitable Breeding Habitat for Frogs in Xishuangbanna, China

    PubMed Central

    Behm, Jocelyn E.; Yang, Xiaodong; Chen, Jin

    2013-01-01

    Conversion of tropical forests into agriculture may present a serious risk to amphibian diversity if amphibians are not able to use agricultural areas as habitat. Recently, in Xishuangbanna Prefecture, Yunnan Province – a hotspot of frog diversity within China – two-thirds of the native tropical rainforests have been converted into rubber plantation agriculture. We conducted surveys and experiments to quantify habitat use for breeding and non-breeding life history activities of the native frog species in rainforest, rubber plantation and other human impacted sites. Rubber plantation sites had the lowest species richness in our non-breeding habitat surveys and no species used rubber plantation sites as breeding habitat. The absence of breeding was likely not due to intrinsic properties of the rubber plantation pools, as our experiments indicated that rubber plantation pools were suitable for tadpole growth and development. Rather, the absence of breeding in the rubber plantation was likely due to a misalignment of breeding and non-breeding habitat preferences. Analyses of our breeding surveys showed that percent canopy cover over pools was the strongest environmental variable influencing breeding site selection, with species exhibiting preferences for pools under both high and low canopy cover. Although rubber plantation pools had high canopy cover, the only species that bred in high canopy cover sites used the rainforest for both non-breeding and breeding activities, completing their entire life cycle in the rainforest. Conversely, the species that did use the rubber plantation for non-breeding habitat preferred to breed in low canopy sites, also avoiding breeding in the rubber plantation. Rubber plantations are likely an intermediate habitat type that ‘slips through the cracks’ of species habitat preferences and is thus avoided for breeding. In summary, unlike the rainforests they replaced, rubber plantations alone may not be able to support frog

  16. Monitoring the abundance of Aedes (Ochlerotatus) albifasciatus (Macquart 1838) (Diptera: Culicidae) to the south of Mar Chiquita Lake, central Argentina, with the aid of remote sensing.

    PubMed

    Gleiser, R M; Gorla, D E; Ludueña Almeida, F F

    1997-12-01

    Surges in the size of adult populations of the flood-water mosquito Aedes albifasciatus can produce important economical losses because of the way this species irritates livestock. Although this species is also the main vector of west equine encephalitis in Argentina, little is known about the factors affecting its population dynamics, as it is difficult to obtain data on its abundance over a large area. However, the results of intensive study of the mosquito in a few sites might reasonably be extrapolated to a regional scale by the use of remotely sensed data. The adult, larval and pupal stages of Ae. albifasciatus were sampled at five field sites to the south of Mar Chiquita Lake, either once a month (during the dry, cold season) or once a fortnight (during the warm, rainy season), between August 1992 and April 1993. The measured abundance of adults or pre-adults and a meteorological coefficient useful for the estimation of larval abundance each showed significant correlation with various statistics derived from normalized-difference, vegetation indices (NDVI) calculated from satellite (NOAA-AVHRR) imagery. A linear discriminant analysis, using data on NDVI, rainfall and temperature, accurately identified periods with and without pre-adults. The satellite imagery was also useful in the estimation of larval abundance and consequently could be used to predict adult abundance 7 days in advance. Even though the satellite data employed have poor spatial resolution, their high temporal resolution makes them very useful in studies of the population dynamics of mosquitoes in general, at least once the relevant variables and their relationships with mosquito breeding and survival have been identified. PMID:9579211

  17. Male reproductive biology of Aedes mosquitoes.

    PubMed

    Oliva, Clelia F; Damiens, David; Benedict, Mark Q

    2014-04-01

    Among Aedes mosquitoes are species responsible for transmission of serious pathogens to humans. To cope with the current threats to long-term effectiveness of the traditional vector control methods, non-conventional control strategies are being developed. These include autocidal control such as the release of sterile males (sterile insect technique) and the release of Wolbachia-infected males to induce sexual sterility (incompatible insect technique) and pathogen-refractory strain replacement variations using Wolbachia. Sterile male types of techniques particularly depend on released males' ability to successfully mate with wild females. For that reason, a good understanding of male mating biology, including a thorough understanding of the reproductive system and mating capacity, increases the likelihood of success of such genetic vector control programmes. Here we review the literature concerning the reproduction of Aedes mosquitoes with an emphasis on the male biology. We consider sexual maturation, mate finding, insemination, male reproductive capacity, and the occurrence of multiple matings. We also discuss which parameters are of greatest importance for the successful implementation of autocidal control methods and propose questions for future research. PMID:24308996

  18. High affinity 3H-Phe uptake by brush border membrane vesicles from whole larvae of Aedes aegypti (AaBMVw)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brush border membrane vesicles from whole Aedes aegypti larvae (AaBBMVw) are confirmed to be valid preparations for membrane transport studies. The Abdul-Rauf and Ellar method was used to isolate AaBBMVw that were frozen, stored for several months, transported to a distant site, thawed and used to s...

  19. Post-breeding migration of Dutch-breeding black-tailed godwits: timing, routes, use of stopovers, and nonbreeding destinations

    USGS Publications Warehouse

    Hooijmeijer, Jos C. E. W.; Senner, Nathan R.; Tibbitts, T. Lee; Gill, Robert E., Jr.; Douglas, David C.; Bruinzeel, Leo W.; Wymenga, Eddy; Piersma, Theunis

    2014-01-01

    Conservation of long-distance migratory shorebirds is complex because these species use habitats spread across continents and hemispheres, making identification of critical habitats and potential bottlenecks in the annual cycle especially difficult. The population of Black-tailed Godwits that breeds in Western Europe, Limosa limosa limosa, has declined precipitously over the past few decades. Despite significant efforts to identify the root causes of this decline, much remains unclear. To better understand the migratory timing, use of stopover and nonbreeding sites, and the potential impact of breeding success on these parameters, we attached 15 Argos satellite transmitters and 10 geolocation tracking devices to adult godwits nearing completion of incubation at breeding sites in southwest Friesland, The Netherlands during the spring of 2009. We successfully tracked 16 adult godwits for their entire southward migration and two others for part of it. Three migration patterns and four regions of use were apparent. Most godwits left their breeding sites and proceeded south directly to stopover sites in the Mediterranean — e.g. Spain, Portugal, and Morocco — before flying on to non-breeding sites in West Africa. Other individuals spent the entire nonbreeding season in the Mediterranean. A third pattern included a few individuals that flew nonstop from their Dutch breeding sites to nonbreeding sites in West Africa. Tracking data from this study will be immediately useful for conservation efforts focused on preserving the dispersed network of sites used by godwits during their southward migration.

  20. Aedes (Stegomyia) aegypti and Aedes (Howardina) cozumelensis in Yucatán State, México, with a summary of published collection records for Ae. cozumelensis

    PubMed Central

    García-Rejón, Julián E.; López-Uribe, Mildred P.; Loroño-Pino, María Alba; Arana-Guardia, Roger; Puc-Tinal, Maria; López-Uribe, Genny M.; Coba-Tún, Carlos; Baak-Baak, Carlos M.; Machain-Williams, Carlos; Reyes-Solis, Guadalupe C.; Lozano-Fuentes, Saul; Saavedra-Rodriguez, Karla; Black IV, William C.; Beaty, Barry J.; Eisen, Lars

    2013-01-01

    We collected mosquito immatures from artificial containers during 2010–2011 from 26 communities, ranging in size from small rural communities to large urban centers, located in different parts of Yucatán State in southeastern México. The arbovirus vector Aedes (Stegomyia) aegypti was collected from all 26 examined communities, and nine of the communities also yielded another container-inhabiting Aedes mosquito: Aedes (Howardina) cozumelensis. The communities from which Ae. cozumelensis were collected were all small, rural communities (<6,000 inhabitants) in the north-central part of Yucatán State. These new collection records for Ae. cozumelensis demonstrate that this mosquito has a far broader geographic range in the Yucatán Peninsula than previously known. Ae. cozumelensis immatures were collected from both residential premises and cemeteries, with specimens recovered from rock holes as well as various artificial containers including metal cans, flower vases, buckets, tires and a water storage tank. The co-occurrence with Ae. aegypti in small rural communities poses intriguing questions regarding linkages between these mosquitoes, including the potential for direct competition for larval development sites. Additional studies are needed to determine how commonly Ae. cozumelensis feeds on human blood and whether it is naturally infected with arboviruses or other pathogens of medical or veterinary importance. We also summarize the published records for Ae. cozumelensis, which are restricted to collections from México’s Yucatán Peninsula and Belize, and uniformly represent geographic locations where Ae. aegypti can be expected to occur. PMID:23181861

  1. Insecticide susceptibility of the dengue vector, Aedes aegypti (L.) in Metropolitan Bangkok.

    PubMed

    Komalamisra, Narumon; Srisawat, Raweewan; Phanbhuwong, Theerawit; Oatwaree, Sompis

    2011-07-01

    Mosquito larvae were collected from the houses of dengue infected patients in Bangkok, Thailand from 55 sites (36 out of the 50 districts of Metropolitan Bangkok). Aedes aegypti larvae were tested against temephos using WHO bioassay techniques. Adult mosquitoes were tested for susceptibility to permethrin, deltamethrin, cyfluthrin, malathion and DDT using WHO diagnostic doses. Most of the larvae tested were susceptible to temephos. Only few specimens were resistant to temephos. Most adult mosquitoes were highly susceptible to malathion. Deltamethrin resistance was seen in 6 districts of Bangkok. Variable levels of susceptibility were seen with cyfluthrin. Most of the specimens showed resistance to permethrin and all specimens were resistant to DDT. PMID:22299463

  2. Chikungunya

    MedlinePlus

    ... focused on relieving the symptoms. The proximity of mosquito breeding sites to human habitation is a significant ... bites of infected Aedes aegypti and Aedes albopictus mosquitos, both present in the Americas. After the bite ...

  3. Participatory definition of breeding objectives for sheep breeds under pastoral systems--the case of Red Maasai and Dorper sheep in Kenya.

    PubMed

    König, Emelie Zonabend; Mirkena, Tadele; Strandberg, Erling; Audho, James; Ojango, Julie; Malmfors, Birgitta; Okeyo, Ally Mwai; Philipsson, Jan

    2016-01-01

    Crossing local breeds with exotic breeds may be an option for increased livestock productivity. However, there is a risk for endangerment of the local breeds. One such case is in Kenya where the imported Dorper breed is used for crossbreeding with Red Maasai sheep. The aim of this study was to investigate farmers' trait preferences as a basis for determination of breeding objectives for Red Maasai and Dorper sheep at two sites, Amboseli and Isinya, in Kenya. Within their own flock, each farmer identified three ewes representing the best, average and poorest within each breed group: Red Maasai, Dorper and Crosses. Farmers gave reasons for their ranking. Body measurements and weights were also taken. At the harshest site, Amboseli, differences between breed groups in body weight were small and breeds were equally preferred. In Isinya, where environmental conditions are better and farmers are more market oriented, Dorper and Crosses had significantly higher body weights and market prices and were thus preferred by the farmers. Red Maasai were preferred for their maternal and adaptive traits. Breeding objectives should emphasize growth traits and milk production in both breeds at both sites. Body condition needs to be specifically considered in the breeding objectives for sheep in Amboseli, whereas adaptive traits need to be generally emphasized in Dorper. PMID:26374208

  4. FISH landmarks for Aedes aegypti chromosomes.

    PubMed

    Brown, S E; Knudson, D L

    1997-05-01

    Aedes aegypti metaphase chromosome landmarks have been developed so that each chromosome of the haploid genome can be unambiguously identified and oriented by fluorescence in situ hybridization (FISH) and digital imaging microscopy. The FISH tags were derived from three cosmids that contain repetitive Ae. aegypti sequences and their unique FISH tagging characteristics are demonstrated. The sequence of the three chromosomal tags revealed that the chromosome 1 tag is an 18S fragment from the ribosomal cistron, and the other two chromosomal tags are repeats found in Ae. aegypti with no apparent similarity to known sequences. A single plasmid that contains the three chromosomes tag sequences has been constructed to simplify future FISH physical mapping. PMID:9099584

  5. The Aedes aegypti genome: a comparative perspective.

    PubMed

    Waterhouse, R M; Wyder, S; Zdobnov, E M

    2008-02-01

    The sequencing of the second mosquito genome, Aedes aegypti, in addition to Anopheles gambiae, is a major milestone that will drive molecular-level and genome-wide high-throughput studies of not only these but also other mosquito vectors of human pathogens. Here we overview the ancestry of the mosquito genes, list the major expansions of gene families that may relate to species adaptation processes, as exemplified by CYP9 cytochrome P450 genes, and discuss the conservation of chromosomal gene arrangements among the two mosquitoes and fruit fly. Many more invertebrate genomes are expected to be sequenced in the near future, including additional vectors of human pathogens (see http://www.vectorbase.org), and further comparative analyses will become increasingly refined and informative, hopefully improving our understanding of the genetic basis of phenotypical differences among these species, their vectorial capacity, and ultimately leading to the development of novel disease control strategies. PMID:18237279

  6. History of Aedes mosquitoes in Hawaii.

    PubMed

    Winchester, Jonathan C; Kapan, Durrell D

    2013-06-01

    As a geographically isolated island chain with no native mosquitoes, Hawaii is a model for examining the mechanisms behind insect vector invasions and their subsequent interactions with each other and with human populations. The yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Ae. albopictus, have been responsible for epidemics of dengue in Hawaii. As one of the world's earliest locations to be invaded by both species, Hawaii's history is particularly relevant because both species are currently invading new areas worldwide and are implicated in outbreaks of emergent or reemergent pathogens such as dengue, chikungunya, and yellow fever. Here we analyze the historical records of mosquito introductions in order to understand the factors that have led to the current distribution of these 2 mosquitoes in the Hawaiian Islands. PMID:23923330

  7. Breeding Cold Hardy Begonias

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hardy begonia cultivars have potential as a new crop for Southern nurseries. Current begonia breeding efforts are focused on sections Begonia and Pritzelia. Diverse begonia germplasm has been collected to study fertility and hardiness.To date cold hardy germplasm which has produced viable seeds inc...

  8. Hop Cultivars and Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pest management decision making in hops varies among cultivars. Historically, the primary objective of hop breeding programs has been to increase the yield or characteristics associated with either bittering (high alpha-acids) or aroma (unique volatile oil profiles) cultivars. Other factors consid...

  9. Red Clover Breeding Progress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red clover (Trifolium pratense L.) is an important forage legume grown on approximately 4 million hectares worldwide. It has a long and varied history in agriculture. Active breeding efforts began at the end of the 19th century. Since this time significant improvement in red clover cultivar for a...

  10. Raspberry Breeding and Genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter describes the origin, speciation, and history of improvement of the raspberries, Rubus section idaeobatus. The world industry in North America, Australasia, China, Europe, Eastern Europe, Africa, and South America and the breeding objectives of programs in those areas are discussed. Ger...

  11. Effects of breeding success, mate fidelity and senescence on breeding dispersal of male and female blue-footed boobies.

    PubMed

    Kim, Sin-Yeon; Torres, Roxana; Rodríguez, Cristina; Drummond, Hugh

    2007-05-01

    1. Understanding the effects of individual and population factors on variation in breeding dispersal (the movement of individuals between successive breeding sites) is key to identifying the strategies behind breeders' movements. Dispersal is often influenced by multiple factors and these can be confounded with each other. We used 13 years of data on the locations, mates, breeding success and ages of individuals to tease apart the factors influencing breeding dispersal in a colonially breeding long-lived seabird, the blue-footed booby Sula nebouxii. 2. Breeding dispersal varied among and within years. Males dispersed further in years of higher population density, and late breeding males and females dispersed further than early breeders. This temporal variation related to changes in competition for territory was taken into account in all tests of individual factors influencing breeding dispersal. 3. Individuals that retained their mates from the previous year dispersed shorter distances than those that changed their mates. 4. The effect of previous breeding success depended on mate fidelity. Unsuccessful breeding induced greater dispersal in birds that changed their mates but not in birds that retained their mates, indicating that breeders who change mates may take their own previous breeding experience into account during habitat selection. Faithful individuals may have to stay close to their previous sites to encounter their mates. 5. Male divorcees dispersed over shorter distances than their former mates, possibly because males contribute more than females to establishing territories. 6. Dispersal of males and females declined with increasing age over the first 10-11 years of life, then increased in old age, possibly due to senescent decay in the ability to compete for mates and territories. PMID:17439464

  12. Larvicidal potential of silver nanoparticles synthesized using fungus Cochliobolus lunatus against Aedes aegypti (Linnaeus, 1762) and Anopheles stephensi Liston (Diptera; Culicidae).

    PubMed

    Salunkhe, Rahul B; Patil, Satish V; Patil, Chandrashekhar D; Salunke, Bipinchandra K

    2011-09-01

    Larvicides play a vital role in controlling mosquitoes in their breeding sites. The present study was carried out to establish the larvicidal activities of mycosynthesized silver nanoparticles (AgNPs) against vectors: Aedes aegypti and Anopheles stephensi responsible for diseases of public health importance. The AgNPs synthesized by filamentous fungus Cochliobolus lunatus, characterized by UV-Vis spectrophotometry, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The characterization studies confirmed the spherical shape and size (3-21 nm) of silver nanoparticles. The efficacy of mycosynthesized AgNPs at all the tested concentrations (10, 5, 2.5, 1.25, 0.625, and 0.3125 ppm) against second, third, and fourth instar larvae of A. aegypti (LC(50) 1.29, 1.48, and 1.58; LC(90) 3.08, 3.33, and 3.41 ppm) and against A. stephensi (LC(50) 1.17, 1.30, and 1.41; LC(90) 2.99, 3.13, and 3.29 ppm) were observed, respectively. The mortality rates were positively correlated with the concentration of AgNPs. Significant (P < 0.05) changes in the larval mortality was also recorded between the period of exposure against fourth instar larvae of A. aegypti and A. stephensi. The possible larvicidal activity may be due to penetration of nanoparticles through membrane. Toxicity studies carried out against non-target fish species Poecilia reticulata, the most common organism in the habitats of A. aegypti and A. stephensi showed no toxicity at LC50 and LC90 doses of the AgNPs. This is the first report on mosquito larvicidal activity of mycosynthesized nanoparticles. Thus, the use of fungus C. lunatus to synthesize silver nanoparticles is a rapid, eco-friendly, and a single-step approach and the AgNps formed can be potential mosquito larvicidal agents. PMID:21451993

  13. Breeding productivity of Smith Island black ducks

    USGS Publications Warehouse

    Haramis, G.M.; Jorde, D.G.; Olsen, G.H.; Stotts, D.B.; Harrison, M.K.

    2002-01-01

    We investigated the breeding performance of American black ducks (Anas rubripes) on Smith Island, Chesapeake Bay, to improve our understanding of island black duck breeding ecology and to make management recommendations to enhance productivity. During 1995-96, we implanted 56 female black ducks with 20-g radio transmitters and tracked 35 of the individuals through the breeding season to locate nests, determine nest fate, and identify brood habitat. We also increased preseason banding efforts and compared capture characteristics over 12 years with those from the Deal Island Wildlife Management Area, a banding site on the mainland of Tangier Sound. A low rate of nesting (37%), lack of renesting, and poor hatching success (31%) indicated that island salt marsh habitats present a harsh environment for breeding black ducks. Black ducks located 11 of 13 nests (85%) in black needlerush (Juncus roemerianus) marsh where they were vulnerable to flooding from extreme tides and to egg predators. No nests were found on forested tree hammocks, a feature that distinguishes Smith Island from nearby South Marsh and Bloodsworth Islands. Nest predators included red foxes (Vulpes vulpes), herring gulls (Larus argentams), fish crows (Corvus ossifragus), and, potentially, Norway rats (Rattus norvegicus). Unlike mainland red foxes, foxes radio tracked on Smith Island were found to be capable swimmers and effective low marsh predators. We found shoreline meadows of widgeon grass (Ruppia maritima) to be important foraging sites for black ducks and suspected that the virtual absence of fresh water in this high salinity environment (1217+ ppt) to incur some cost in terms of growth and survival of ducklings. Preseason bandings revealed a high proportion of banded adults and a strong positive correlation in age ratios with the Deal Island banding site. This latter finding strongly suggests a negative universal effect of storm tides on nest success for Tangier Sound black ducks. Management to

  14. Area-wide management of Aedes albopictus: gauging the efficacy of multiple control measures during 2010.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aedes albopictus is a major human biting pest and is considered second only to Aedes aegypti in its importance as a disease vector of dengue. Aedes albopictus is responsible for the majority of service requests from urban and suburban residents in New Jersey during recent years; however, standard a...

  15. Crystal Structures of Aedes Aegypt Alanine Glyoxylate Aminotransferase

    SciTech Connect

    Han,Q.; Robinson, H.; Gao, Y.; Vogelaar, N.; Wilson, S.; Rizzi, M.; Li, J.

    2006-01-01

    Mosquitoes are unique in having evolved two alanine glyoxylate aminotransferases (AGTs). One is 3-hydroxykynurenine transaminase (HKT), which is primarily responsible for catalyzing the transamination of 3-hydroxykynurenine (3-HK) to xanthurenic acid (XA). Interestingly, XA is used by malaria parasites as a chemical trigger for their development within the mosquito. This 3-HK to XA conversion is considered the major mechanism mosquitoes use to detoxify the chemically reactive and potentially toxic 3-HK. The other AGT is a typical dipteran insect AGT and is specific for converting glyoxylic acid to glycine. Here we report the 1.75{angstrom} high-resolution three-dimensional crystal structure of AGT from the mosquito Aedes aegypti (AeAGT) and structures of its complexes with reactants glyoxylic acid and alanine at 1.75 and 2.1{angstrom} resolution, respectively. This is the first time that the three-dimensional crystal structures of an AGT with its amino acceptor, glyoxylic acid, and amino donor, alanine, have been determined. The protein is dimeric and adopts the type I-fold of pyridoxal 5-phosphate (PLP)-dependent aminotransferases. The PLP co-factor is covalently bound to the active site in the crystal structure, and its binding site is similar to those of other AGTs. The comparison of the AeAGT-glyoxylic acid structure with other AGT structures revealed that these glyoxylic acid binding residues are conserved in most AGTs. Comparison of the AeAGT-alanine structure with that of the Anopheles HKT-inhibitor complex suggests that a Ser-Asn-Phe motif in the latter may be responsible for the substrate specificity of HKT enzymes for 3-HK.

  16. Sustained, Area-Wide Control of Aedes aegypti Using CDC Autocidal Gravid Ovitraps

    PubMed Central

    Barrera, Roberto; Amador, Manuel; Acevedo, Verónica; Hemme, Ryan R.; Félix, Gilberto

    2014-01-01

    We have shown that the Centers for Disease Control and Prevention (CDC) autocidal gravid ovitraps (AGO trap) reduced the Aedes aegypti population and prevented mosquito outbreaks in southern Puerto Rico. After showing treatment efficacy for 1 year, we deployed three traps per home in an area that formerly did not have traps and in a site that served as the intervention area. Two new areas were selected as reference sites to compare the density of Ae. aegypti without traps. We monitored mosquitoes and weather every week in all four sites. The hypotheses were the density of Ae. aegypti in the former reference area converges to the low levels observed in the intervention area, and mosquito density in both areas having control traps is lower than in the new reference areas. Mosquito density in the former reference area decreased 79% and mosquito density in the new reference areas was 88% greater than in the intervention areas. PMID:25223937

  17. Failure of Aedes albopictus to overwinter following introduction and seasonal establishment at a tire recycling plant in the northeastern USA.

    PubMed

    Andreadis, Theodore G

    2009-03-01

    In July 2006, an introduction of the Asian tiger mosquito, Aedes albopictus, was documented for the first time at a commercial tire recycling plant in northeastern Connecticut, USA. The introduction likely occurred via transport of infested tires originating from northern New Jersey or metropolitan New York City. Efforts were made to determine seasonal establishment and overwintering success by assessing adult biting and oviposition activity in the surrounding woodlands. The first adult female was collected in a CO2-baited Mosquito Magnet Liberty trap within the confines of the tire plant during the week of July 28. Additional females were collected intermittently thereafter through October 16. Host-seeking female Ae. albopictus attempting to alight on human subjects and larvae hatching from eggs collected in ovitraps placed in the woodlands surrounding the tire plant were detected weekly from August 21 through October 2, denoting seasonal establishment in the adjoining woodlands. However, no larvae of Ae. albopictus were recovered from eggs collected in ovitraps that were placed in the surrounding woodlands or in traps placed 1.0-1.6 km away, nor were any host-seeking females detected by human subjects the following season (July to October 2007), indicating that the species did not survive winter conditions to enable successful colonization. The failure of Ae. albopictus to overwinter and establish itself in the forested woodlands following several weeks of seasonal breeding and oviposition during the summer and early fall were most likely due to winter egg mortality, interspecific competition from Aedes triseriatus and Aedes japonicus, and/or other ecological barriers. Permanent establishment of Ae. albopictus in New England is unlikely despite the recurring importation of infested used tires into recycling facilities. However, continued monitoring of such facilities for potential reinvasion is warranted especially in urban/suburban environs where global warming

  18. Insecticide susceptibility of Aedes aegypti populations from Senegal and Cape Verde Archipelago

    PubMed Central

    2012-01-01

    Background Two concomitant dengue 3 (DEN-3) epidemics occurred in Cape Verde Archipelago and Senegal between September and October 2009. Aedes aegypti was identified as the vector of these epidemics as several DEN-3 virus strains were isolated from this species in both countries. The susceptibility to pyrethroids, organochlorine, organophosphates and carbamate was investigated in two field strains of Aedes aegypti from both countries using WHO diagnostic bioassay kits in order to monitor their the current status of insecticide susceptibility. Findings The two tested strains were highly resistant to DDT. The Cape Verde strain was found to be susceptible to all others tested insecticides except for propoxur 0.1%, which needs further investigation. The Dakar strain was susceptible to fenitrothion 1% and permethrin 0.75%, but displayed reduced susceptibility to deltamethrin, lambda-cyhalothrin and propoxur. Conclusions As base-line results, our observations stress a careful management of insecticide use for the control of Ae. aegypti. Indeed, they indicate that DDT is no longer efficient for the control of Ae. aegypti populations in Cape Verde and Dakar and further suggest a thorough follow-up of propoxur susceptibility status in both sites and that of deltamethrin and lambda-cyhalothrin in Ae. aegypti populations in Dakar. Thus, regular monitoring of susceptibility is greatly needed as well as the knowing if this observed resistance/susceptibility is focal or not and for observed resistance, the use of biochemical methods is needed with detailed comparison of resistance levels over a large geographic area. Keywords Aedes aegypti, Insecticides, Susceptibility, Cape Verde, Senegal PMID:23088621

  19. Aedes aegypti (L.) and Aedes albopictus (Skuse) in Singapore City. 2. Larval habitats.

    PubMed

    Chan, K L; Ho, B C; Chan, Y C

    1971-01-01

    Detailed information on the breeding habitats of Ae. aegypti and Ae. albopictus is necessary when planning programmes for their control. The larval habitats of the two species in 10 city areas were counted and classified according to type, frequency of occurrence, location, and function. Of all the breeding habitats recorded 95% were domestic containers. The most common Ae. aegypti breeding habitats were ant traps, earthenware jars, bowls, tanks, tin cans, and drums, ant traps being the most common indoors and earthenware jars the most common out doors. Breeding habitats for Ae. albopictus were commonly found in earthen ware jars, tin cans, ant traps, rubber tires, bowls, and drums; ant traps were the most common indoor habitat and tin cans were most common outdoors.The majority of Ae. aegypti breeding habitats were found indoors, while only half of all the Ae. albopictus breeding habitats were indoors. The indoor and outdoor distribution of breeding habitats of both species was not related to the type of housing in the area.The distribution of the type of breeding habitats, however, was related to the type of housing in the area. Ant traps were common to all areas, but water-storage containers and unused containers were common in slum-house and shop-house areas. Flats, however, had more containers used for keeping plants and flowers.The most common breeding habitats of Ae. aegypti and Ae. albopictus are discussed in relation to the habits of the people. It is concluded that control of the two species will depend largely on a change in such habits, either through public health education or by some form of law enforcement. PMID:5316746

  20. Seasonal changes in the larvel populations of Aedes aegypti in two biotopes in Dar es Salaam, Tanzania

    PubMed Central

    Trpis, Milan

    1972-01-01

    The seasonal dynamics of larval populations of Aedes aegypti was studied in two different biotopes in Dar es Salaam, Tanzania. The first biotope was located on the Msasani peninsula on the coast 6 km north of Dar es Salaam, where A. aegypti breeds exclusively in coral rock holes. The population dynamics was studied during both the rainy and the dry season. Seasonal changes in the density of A. aegypti larvae depend primarily on variation in rainfall. The population of larvae dropped to zero only for a short time during the driest period while the adult population was maintained at a low level. The second biotope was in an automobile dump in a Dar es Salaam suburb, where A. aegypti breeds in artificial containers such as tires, automobile parts, tins, coconut shells, and snail shells. The greater part of the A. aegypti population of this biotope is maintained in the egg stage during the dry season. It serves as a focal point for breeding during the dry season: with the coming of the rains, the population expands into the surrounding residential areas. More than 70% of the larval population developed in tires, 20% in tins, 5% in coconut shells, and 1% in snail shells. PMID:4539415

  1. Interspecific Larval Competition Between Aedes albopictus and Aedes japonicus (Diptera: Culicidae) in Northern Virginia

    PubMed Central

    Armistead, J. S.; Arias, J. R.; Nishimura, N.; Lounibos, L. P.

    2008-01-01

    Aedes albopictus (Skuse) and Aedes japonicus (Theobald) are two of the most recent and widespread invasive mosquito species to have become established in the United States. The two species co-occur in water-filled artificial containers, where crowding and limiting resources are likely to promote inter- or intraspecific larval competition. The performance of northern Virginia populations of Ae. japonicus and Ae. albopictus competing as larvae under field conditions was evaluated. Per capita rates of population increase for each species were estimated, and the effects of species composition and larval density were determined. In water-containing cups provided with oak leaves, Ae. albopictus larvae exhibited a competitive advantage over Ae. japonicus as a consequence of higher survivorship, shorter developmental time, and a significantly higher estimated population growth rate under conditions of interspecific competition. Intraspecific competition constrained population performance of Ae. albopictus significantly more than competition with Ae. japonicus. In the context of the Lotka-Volterra model of competition, these findings suggest competitive exclusion of Ae. japonicus in those habitats where this species co-occurs with Ae. albopictus. PMID:18714861

  2. Comparative study on nocturnal behavior of Aedes aegypti and Aedes albopictus.

    PubMed

    Kawada, Hitoshi; Takemura, Shin-Ya; Arikawa, Kentaro; Takagi, Masahiro

    2005-05-01

    Nocturnal behavior of nonblood-fed females of Aedes aegypti (L.) and Aedes albopictus (Skuse) was studied using an automatic recording device equipped with a photoelectric sensor. Carbon dioxide, heating, and the contrast of the black and white colors were used as attractive cues for mosquitoes. The nocturnal host-seeking activity positively correlated with the increasing light intensity in both species. Ae. aegypti was found to be more sensitive to light than Ae. albopictus. The threshold of light intensity for the activation of the nocturnal host-seeking activity was <0.1 lx (approximately 0.01 foot candle) in Ae. aegypti and >10 lx (approximately 1 foot candle) in Ae. albopictus. Complete darkness during the daytime deactivated the host-seeking activity of both species, irrespective of their increasing flight activity controlled by their intrinsic circadian rhythms. This finding suggested that visual cues are indispensable for host-seeking behavior. The eye parameter value, the product of the ommatidial diameter, and the interommatidial angle were significantly larger in Ae. aegypti than those in Ae. albopictus, indicating that the eye of Ae. aegypti is more adapted to a darker environment. PMID:15962780

  3. Male accessory gland substances from Aedes albopictus affect the locomotor activity of Aedes aegypti females

    PubMed Central

    Lima-Camara, Tamara Nunes; Codeço, Claudia Torres; Honório, Nildimar Alves; Bruno, Rafaela Vieira; Peixoto, Alexandre Afranio; Lounibos, Leon Philip

    2013-01-01

    Dengue is one of the world’s most important mosquito-borne diseases and is usually transmitted by one of two vector species: Aedes aegypti or Aedes albopictus . These two diurnal mosquitoes are frequently found coexisting in similar habitats, enabling interactions between adults, such as cross-mating. The objective of this study was to assess cross-mating between Ae. aegypti females and Ae. albopictus males under artificial conditions and evaluate the locomotor activity of Ae. aegypti virgin females injected with male accessory gland (MAG) homogenates to infer the physiological and behavioural responses to interspecific mating. After seven days of exposure, 3.3-16% of Ae. aegypti females mated with Ae. albopictus males. Virgin Ae. aegypti females injected with conspecific and heterospecific MAGs showed a general decrease in locomotor activity compared to controls and were refractory to mating with conspecific males. The reduction in diurnal locomotor activity induced by injections of conspecific or heterospecific MAGs is consistent with regulation of female reproductive activities by male substances, which are capable of sterilising female Ae. aegypti through satyrisation by Ae. albopictus . PMID:24473799

  4. Autophagy and viral diseases transmitted by Aedes aegypti and Aedes albopictus.

    PubMed

    Carneiro, Leticia A M; Travassos, Leonardo H

    2016-03-01

    Despite a long battle that was started by Oswaldo Cruz more than a century ago, in 1903, Brazil still struggles to fight Aedes aegypti and Aedes albopictus, the mosquito vectors of dengue virus (DENV), Chikungynya virus (CHIKV) and Zika virus (ZIKV). Dengue fever has been a serious public health problem in Brazil for decades, with recurrent epidemic outbreaks occurring during summers. In 2015, until November, 1,534,932 possible cases were reported to the Ministry of Healthv. More recently, the less studied CHIKV and ZIKV have gained attention because of a dramatic increase in their incidence (around 400% for CHIKV) and the association of ZIKV infection with a 11-fold increase in the number of cases of microcephaly from 2014 to 2015 in northeast Brazil (1761 cases until December 2015). The symptoms of these three infections are very similar, which complicates the diagnosis. These include fever, headache, nausea, fatigue, and joint pain. In some cases, DENV infection develops into dengue hemorrhagic fever, a life threatening condition characterized by bleeding and decreases in platelet numbers in the blood. As for CHIKV, the most important complication is joint pain, which can last for months. PMID:26774331

  5. Widespread evidence for interspecific mating between Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in nature.

    PubMed

    Bargielowski, I E; Lounibos, L P; Shin, D; Smartt, C T; Carrasquilla, M C; Henry, A; Navarro, J C; Paupy, C; Dennett, J A

    2015-12-01

    Aedes aegypti and Aedes albopictus, two important vectors of the dengue and chikungunya viruses to humans, often come in contact in their invasive ranges. In these circumstances, a number of factors are thought to influence their population dynamics, including resource competition among the larval stages, prevailing environmental conditions and reproductive interference in the form of satyrization. As the distribution and abundance of Ae. aegypti and Ae. albopictus have profound epidemiological implications, understanding the competitive interactions that influence these patterns in nature is important. While evidence for resource competition and environmental factors had been gathered from the field, the evidence for reproductive interference, though strongly inferred through laboratory trials, remained sparse (one small-scale field trial). In this paper we demonstrate that low rates (1.12-3.73%) of interspecific mating occur in nature among populations of these species that have co-existed sympatrically from 3 to 150yrs. Finally this report contributes a new species-specific primer set for identifying the paternity of sperm extracted from field collected specimens. PMID:26296606

  6. Using Wolbachia-based release for suppression of Aedes mosquitoes: insights from genetic data and population simulations.

    PubMed

    Rasić, Gordana; Endersby, Nancy M; Williams, Craig; Hoffmann, Ary A

    2014-07-01

    A novel strategy for suppressing disease transmission by Aedes aegypti, the main vector of dengue, uses releases of mosquitoes infected with the bacterium Wolbachia pipientis. Wolbachia are currently released to interfere with viral transmission, but there is also potential to use strains in mosquito suppression and elimination programs via the deleterious effects of the bacterium on the host. Mosquito suppression depends on target areas being relatively isolated to prevent reinvasion and on local climatic conditions. Here we explored the opportunity for suppression of A. aegypti in central Queensland, Australia, by using microsatellite data and simulations based on CIMSiM models of local weather conditions and breeding container data. Our results indicate that Wolbachia-induced extinctions in central Queensland are possible, although they may eventually be compromised by ongoing mosquito migration between towns until these sources are also suppressed. The results highlight a novel use of deleterious Wolbachia infections to achieve ecological as well as disease-related endpoints. PMID:25154109

  7. Mathematical model of temephos resistance in Aedes aegypti mosquito population

    NASA Astrophysics Data System (ADS)

    Aldila, D.; Nuraini, N.; Soewono, E.; Supriatna, A. K.

    2014-03-01

    Aedes aegypti is the main vector of dengue disease in many tropical and sub-tropical countries. Dengue became major public concern in these countries due to the unavailability of vaccine or drugs for dengue disease in the market. Hence, the only way to control the spread of DF and DHF is by controlling the vectors carrying the disease, for instance with fumigation, temephos or genetic manipulation. Many previous studies conclude that Aedes aegypti may develop resistance to many kind of insecticide, including temephos. Mathematical model for transmission of temephos resistance in Aedes aegypti population is discussed in this paper. Nontrivial equilibrium point of the system and the corresponding existence are shown analytically. The model analysis have shown epidemiological trends condition that permits the coexistence of nontrivial equilibrium is given analytically. Numerical results are given to show parameter sensitivity and some cases of worsening effect values for illustrating possible conditions in the field.

  8. Stage-Structured Population Dynamics of AEDES AEGYPTI

    NASA Astrophysics Data System (ADS)

    Yusoff, Nuraini; Budin, Harun; Ismail, Salemah

    Aedes aegypti is the main vector in the transmission of dengue fever, a vector-borne disease affecting world population living in tropical and sub-tropical countries. Better understanding of the dynamics of its population growth will help in the efforts of controlling the spread of this disease. In looking at the population dynamics of Aedes aegypti, this paper explored the stage-structured modeling of the population growth of the mosquito using the matrix population model. The life cycle of the mosquito was divided into five stages: eggs, larvae, pupae, adult1 and adult2. Developmental rates were obtained for the average Malaysian temperature and these were used in constructing the transition matrix for the matrix model. The model, which was based only on temperature, projected that the population of Aedes aegypti will blow up with time, which is not realistic. For further work, other factors need to be taken into account to obtain a more realistic result.

  9. LABORATORY EVALUATION OF THE DEVELOPMENT OF Aedes aegypti IN TWO SEASONS: INFLUENCE OF DIFFERENT PLACES AND DIFFERENT DENSITIES

    PubMed Central

    Lopes, Tatiana Forte; Holcman, Marcia Moreira; Barbosa, Gerson Laurindo; Domingos, Maria de Fatima; Barreiros, Rosa Maria Oliveira Veiga

    2014-01-01

    Aedes aegypti is an important vector in Brazil being the main vector of the dengue-fever. This paper employs survival curves to describe the time in days from larvae to adult forms of Aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. The study was conducted in São Vicente, a coastal city in Southeastern Brazil. The lowest water temperature in winter and in spring was 20 °C and the highest was 26 °C in spring. Higher and more stable temperatures were measured in the intra compared to the peri in both seasons. Consequently, larvae positioned in the intra resulted in the lowest median time to develop in the individual and collective experiment (nine and ten days, respectively). At least 25% of the larvae positioned in the intra in the individual experiment in the spring took only seven days to reach adulthood. Sex ratios and the median time development by sex did not show significant differences. These results indicate that efforts to control Aedes aegypti must be continuous and directed mainly to prevent the intra-domiciliary sites that can be infested in a week in order to reduce the human-vector contact. PMID:25229215

  10. Laboratory evaluation of the development of Aedes aegypti in two seasons: influence of different places and different densities.

    PubMed

    Lopes, Tatiana Forte; Holcman, Marcia Moreira; Barbosa, Gerson Laurindo; Domingos, Maria de Fatima; Barreiros, Rosa Maria Oliveira Veiga

    2014-01-01

    Aedes aegypti is an important vector in Brazil being the main vector of the dengue-fever. This paper employs survival curves to describe the time in days from larvae to adult forms of Aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. The study was conducted in São Vicente, a coastal city in Southeastern Brazil. The lowest water temperature in winter and in spring was 20 °C and the highest was 26 °C in spring. Higher and more stable temperatures were measured in the intra compared to the peri in both seasons. Consequently, larvae positioned in the intra resulted in the lowest median time to develop in the individual and collective experiment (nine and ten days, respectively). At least 25% of the larvae positioned in the intra in the individual experiment in the spring took only seven days to reach adulthood. Sex ratios and the median time development by sex did not show significant differences. These results indicate that efforts to control Aedes aegypti must be continuous and directed mainly to prevent the intra-domiciliary sites that can be infested in a week in order to reduce the human-vector contact. PMID:25229215

  11. Midgut bacterial dynamics in Aedes aegypti.

    PubMed

    Terenius, Olle; Lindh, Jenny M; Eriksson-Gonzales, Karolina; Bussière, Luc; Laugen, Ane T; Bergquist, Helen; Titanji, Kehmia; Faye, Ingrid

    2012-06-01

    In vector mosquitoes, the presence of midgut bacteria may affect the ability to transmit pathogens. We have used a laboratory colony of Aedes aegypti as a model for bacterial interspecies competition and show that after a blood meal, the number of species (culturable on Luria-Bertani agar) that coexist in the midgut is low and that about 40% of the females do not harbor any cultivable bacteria. We isolated species belonging to the genera Bacillus, Elizabethkingia, Enterococcus, Klebsiella, Pantoea, Serratia, and Sphingomonas, and we also determined their growth rates, antibiotic resistance, and ex vivo inhibition of each other. To investigate the possible existence of coadaptation between midgut bacteria and their host, we fed Ae. aegypti cohorts with gut bacteria from human, a frog, and two mosquito species and followed the bacterial population growth over time. The dynamics of the different species suggests coadaptation between host and bacteria, and interestingly, we found that Pantoea stewartii isolated from Ae. aegypti survive better in Ae. aegypti as compared to P. stewartii isolated from the malaria mosquito Anopheles gambiae. PMID:22283178

  12. A method for trapping breeding adult American Oystercatchers

    USGS Publications Warehouse

    McGowan, C.P.; Simons, T.R.

    2005-01-01

    We present an efficient and effective method for trapping adult, breeding American Oystercatchers (Haematopus palliatus) that minimizes disturbance to nesting birds and the risk of trapping injuries. We used a remote controlled mechanical decoy to lure territorial adults to a leg-hold noose-mat trap. We trapped 25 birds over two seasons and were successful on 54% of our trapping attempts in 2003. We only trapped birds before the breeding season or between nesting attempts to reduce nest-site disturbance.

  13. Epidemiological significance of the breeding of mosquitoes in discarded automobile tyres in Zaria, Northern Nigeria.

    PubMed

    Adebote, D A; Kogi, E; Oniye, S J; Akoje, F

    2011-09-01

    Waste automobile tyres are suitable receptacles of rainwater thus capable of supporting the breeding of vector mosquito species in close proximity to humans and altering disease transmission risks. Bionomics of mosquitoes in carelessly discarded tyres was explored to unravel species composition and abundance, physicochemical parameters of microhabitats and epidemiological significance. Of the 1179 larvae isolated from 90/212 (42.45%) positive tyres were ten species belonging to Aedes and Culex genera, including Aedes aegypti (46.56%), Culex albiventris (0.25%), Cx. cinereus (0.25%), Cx. grahami (0.68%), Cx. ingrami (1.44%), Cx. nebulosus (2.37%), Cx. mirificus (0.08%), Cx. pipiens pipiens (0.17%), Cx. quinquefasciatus (47.07%) and Cx. tigripes (1.10%). Abundance of the dominant Ae. aegypti and Cx. quinquefasciatus did not differ significantly (P > 0.05), but was higher than those of the other eight species (P < 0.05). The microhabitat pH (range 5.20-9.50), total dissolved solids (range 15-802 ppm) and electrical conductivity (range 30-1603 microscm 1) were obtained in tyres. Abundance of Cx. quinquefasciatus correlated positively and significantly with EC and TDS of breeding water (P < 0.05). The study revealed high potential of the transmission of filariasis and arboviruses including dengue and yellow fever by mosquitoes domiciled in waste tyres. PMID:23781631

  14. Observations on anopheline breeding in relation to aquatic plants in different breeding habitats of Kheda (Gujarat).

    PubMed

    Kant, Rajni; Srivastava, H C

    2004-09-01

    Water bodies infested with aquatic vegetations may pose problems in mosquito control through bio-environmental methods. Paucity of information pertaining to association of mosquito breeding with aquatic vegetation was the basis for present investigation. The mosquito breeding sites infested with solitary/dominating plant community viz., Eichhornia crassipes, Ipomoea aquatica, Hydrilla verticillata, Nymphea neuchali, Trapa bispinosa, Lemna paucicostata, Trachelomonas spp., Azolla pinnata, Algae spp. and Cynodon dactylon were selected for the study. The investigation revealed that breeding of eleven anopheline species was associated with Eichhornia in different habitats followed by Hydrilla, algae and Cynodon (8 each), Ipomoea and Trapa (6), Lemna. and Nymphea (5), Azolla and Trachelomonas (4). An. subpictus was associated with all types of vegetation. An. annularis, An. nigerrimus and An. barbirostris were associated with nine plant species. An. culicifacies, the principal malaria vector was found breeding in association with seven aquatic plants and showed strong association with Cynodon, Hydrilla and algae. The species diversity in habitats infested with Hydrilla, algae and Cynodon seems to be most favourable for the breeding of An. culicifacies. It is suggested that thinning or removal of such vegetations at regular interval may help to reduce vector population and enhance the efficacy of biological control agents particularly the larvivorous fishes in such habitats. PMID:16509256

  15. Population size of snowy plovers breeding in North America

    USGS Publications Warehouse

    Thomas, Susan M.; Lyons, James E.; Andres, Brad A.; T-Smith, Elise Elliot; Palacios, Eduardo; Cavitt, John F.; Royle, J. Andrew; Fellows, Suzanne D.; Maty, Kendra; Howe, William H.; Mellink, Eric; Melvin, Stefani; Zimmerman, Tara

    2012-01-01

    Snowy Plovers (Charadrius nivosus) may be one of the rarest shorebirds in North America yet a comprehensive assessment of their abundance and distribution has not been completed. During 2007 and 2008, 557 discrete wetlands were surveyed and nine additional large wetland complexes sampled in México and the USA. From these surveys, a population of 23,555 (95% CI = 17,299 – 29,859) breeding Snowy Plovers was estimated. Combining the estimate with information from areas not surveyed, the total North American population was assessed at 25,869 (95% CI = 18,917 – 32,173). Approximately 42% of all breeding Snowy Plovers in North America resided at two sites (Great Salt Lake, Utah, and Salt Plains National Wildlife Refuge, Oklahoma), and 33% of all these were on wetlands in the Great Basin (including Great Salt Lake). Also, coastal habitats in central and southern Texas supported large numbers of breeding plovers. New breeding sites were discovered in interior deserts and highlands and along the Pacific coast of México; approximately 9% of the North American breeding population occurred in México. Because of uncertainties about effects of climate change and current stresses to breeding habitats, the species should be a management and conservation priority. Periodic monitoring should be undertaken at important sites to ensure high quality habitat is available to support the Snowy Plover population.

  16. Materials for breeding blankets

    SciTech Connect

    Mattas, R.F.; Billone, M.C.

    1995-09-01

    There are several candidate concepts for tritium breeding blankets that make use of a number of special materials. These materials can be classified as Primary Blanket Materials, which have the greatest influence in determining the overall design and performance, and Secondary Blanket Materials, which have key functions in the operation of the blanket but are less important in establishing the overall design and performance. The issues associated with the blanket materials are specified and several examples of materials performance are given. Critical data needs are identified.

  17. piggybac- and PhiC31-Mediated Genetic Transformation of the Asian Tiger Mosquito, Aedes albopictus (Skuse)

    PubMed Central

    Labbé, Geneviève M. C.; Nimmo, Derric D.; Alphey, Luke

    2010-01-01

    Background The Asian tiger mosquito, Aedes albopictus (Skuse), is a vector of several arboviruses including dengue and chikungunya. This highly invasive species originating from Southeast Asia has travelled the world in the last 30 years and is now established in Europe, North and South America, Africa, the Middle East and the Caribbean. In the absence of vaccine or antiviral drugs, efficient mosquito control strategies are crucial. Conventional control methods have so far failed to control Ae. albopictus adequately. Methodology/Principal Findings Germline transformation of Aedes albopictus was achieved by micro-injection of embryos with a piggyBac-based transgene carrying a 3xP3-ECFP marker and an attP site, combined with piggyBac transposase mRNA and piggyBac helper plasmid. Five independent transgenic lines were established, corresponding to an estimated transformation efficiency of 2–3%. Three lines were re-injected with a second-phase plasmid carrying an attB site and a 3xP3-DsRed2 marker, combined with PhiC31 integrase mRNA. Successful site-specific integration was observed in all three lines with an estimated transformation efficiency of 2–6%. Conclusions/Significance Both piggybac- and site-specific PhiC31-mediated germline transformation of Aedes albopictus were successfully achieved. This is the first report of Ae. albopictus germline transformation and engineering, a key step towards studying and controlling this species using novel molecular techniques and genetic control strategies. PMID:20808959

  18. Reproductive Incompatibility Involving Senegalese Aedes aegypti (L) Is Associated with Chromosome Rearrangements

    PubMed Central

    Dickson, Laura B.; Sharakhova, Maria V.; Timoshevskiy, Vladimir A.; Fleming, Karen L.; Caspary, Alex; Sylla, Massamba; Black, William C.

    2016-01-01

    Aedes aegypti, the primary vector of dengue, yellow fever and Zika flaviviruses, consists of at least two subspecies. Aedes aegypti (Aaa) is light in color, has pale scales on the first abdominal tergite, oviposits in artificial containers, and preferentially feeds on humans. Aedes aegypti formosus (Aaf), has a dark cuticle, is restricted to sub-Saharan Africa, has no pale scales on the first abdominal tergite and frequently oviposits in natural containers. Scale patterns correlate with cuticle color in East Africa but not in Senegal, West Africa where black cuticle mosquitoes display a continuum of scaling patterns and breed domestically indoors. An earlier laboratory study did not indicate any pre- or postzygotic barriers to gene flow between Aaa and Aaf in East Africa. However, similar attempts to construct F1 intercross families between Aaa laboratory strains and Senegal Ae. aegypti (SenAae) failed due to poor F1 oviposition and low F2 egg-to-adult survival. Insemination and assortative mating experiments failed to identify prezygotic mating barriers. Backcrosses were performed to test for postzygotic isolation patterns consistent with Haldane’s rule modified for species, like Aedes, that have an autosomal sex determining locus (SDL). Egg-pupal survival was predicted to be low in females mated to hybrid F1 males but average when a male mates with a hybrid F1 female. Survival was in fact significantly reduced when females mated to hybrid males but egg-pupal survival was significantly increased when males were mated to hybrid F1 females. These observations are therefore inconclusive with regards to Haldane’s rule. Basic cytogenetic analyses and Fluorescent In Situ Hybridization (FISH) experiments were performed to compare SenAae strains with the IB12 strain of Aaa that was used for genome sequencing and physical mapping. Some SenAae strains had longer chromosomes than IB12 and significantly different centromeric indices on chromosomes 1 and 3. DAPI staining

  19. Reproductive Incompatibility Involving Senegalese Aedes aegypti (L) Is Associated with Chromosome Rearrangements.

    PubMed

    Dickson, Laura B; Sharakhova, Maria V; Timoshevskiy, Vladimir A; Fleming, Karen L; Caspary, Alex; Sylla, Massamba; Black, William C

    2016-04-01

    Aedes aegypti, the primary vector of dengue, yellow fever and Zika flaviviruses, consists of at least two subspecies. Aedes aegypti (Aaa) is light in color, has pale scales on the first abdominal tergite, oviposits in artificial containers, and preferentially feeds on humans. Aedes aegypti formosus (Aaf), has a dark cuticle, is restricted to sub-Saharan Africa, has no pale scales on the first abdominal tergite and frequently oviposits in natural containers. Scale patterns correlate with cuticle color in East Africa but not in Senegal, West Africa where black cuticle mosquitoes display a continuum of scaling patterns and breed domestically indoors. An earlier laboratory study did not indicate any pre- or postzygotic barriers to gene flow between Aaa and Aaf in East Africa. However, similar attempts to construct F1 intercross families between Aaa laboratory strains and Senegal Ae. aegypti (SenAae) failed due to poor F1 oviposition and low F2 egg-to-adult survival. Insemination and assortative mating experiments failed to identify prezygotic mating barriers. Backcrosses were performed to test for postzygotic isolation patterns consistent with Haldane's rule modified for species, like Aedes, that have an autosomal sex determining locus (SDL). Egg-pupal survival was predicted to be low in females mated to hybrid F1 males but average when a male mates with a hybrid F1 female. Survival was in fact significantly reduced when females mated to hybrid males but egg-pupal survival was significantly increased when males were mated to hybrid F1 females. These observations are therefore inconclusive with regards to Haldane's rule. Basic cytogenetic analyses and Fluorescent In Situ Hybridization (FISH) experiments were performed to compare SenAae strains with the IB12 strain of Aaa that was used for genome sequencing and physical mapping. Some SenAae strains had longer chromosomes than IB12 and significantly different centromeric indices on chromosomes 1 and 3. DAPI staining was

  20. Burchellin: study of bioactivity against Aedes aegypti

    PubMed Central

    2014-01-01

    Background The dengue mosquito Aedes aegypti Linnaeus, 1762 is a widespread insect pest of serious medical importance. Since no effective vaccine is available for treating dengue, the eradication or control of the main mosquito vector is regarded as essential. Since conventional insecticides have limited success, plants may be an alternative source of larvicidal agents, since they contain a rich source of bioactive chemicals. The aim of this study was to evaluate the larvicidal activity of the neolignan burchellin isolated from Ocotea cymbarum (Lauraceae), a plant from the Amazon region, against third instar larvae of A. aegypti. Methods Burchellin obtained from O. cymbarum was analyzed. The inhibitory activity against A. aegypti eggs and larvae and histological changes in the digestive system of treated L3 larvae were evaluated. In addition, nitric oxide synthase activity and nitric oxide levels were determined, and cytotoxicity bioassays performed. Results The data showed that burchellin interfered with the development cycle of the mosquito, where its strongest toxic effect was 100% mortality in larvae (L3) at concentrations ≥ 30 ppm. This compound did not show target cell toxicity in peritoneal macrophages from BALB/c mice, and proved to have molecular stability when dissolved in water. The L3 and L4 larvae treated with the compound showed cellular destruction and disorganization, cell spacing, and vacuolization of epithelial cells in small regions of the midgut. Conclusion The neolignan burchellin proved to be a strong candidate for a natural, safe and stable phytolarvicidal to be used in population control of A. aegypti. PMID:24713267

  1. Natural breeding places of phlebotomine sandflies.

    PubMed

    Feliciangeli, M D

    2004-03-01

    Methods of finding larvae and pupae of phlebotomine sandflies (Diptera: Psychodidae) are described and the known types of breeding sites used by sandflies are listed. Three ways of detecting sandfly breeding places are the use of emergence traps placed over potential sources to catch newly emerged adult sandflies; flotation of larvae and pupae from soil, etc., and desiccation of media to drive out the larvae. Even so, remarkably little information is available on the ecology of the developmental stages of sandflies, despite their importance as vectors of Leishmania, Bartonella and phleboviruses affecting humans and other vertebrates in warmers parts of the world. Regarding the proven or suspected vectors of leishmaniases, information on breeding sites is available for only 15 out of 29 species of sandflies involved in the Old World and 12 out of 44 species of sandflies involved in the Americas, representing approximately 3% of the known species of Phlebotominae. Ecotopes occupied by immature phlebotomines are usually organically rich moist soils, such as the rain forest floor (Lutzomyia intermedia, Lu. umbratilis, Lu. whitmani in the Amazon; Lu. gomezi, Lu. panamensis, Lu. trapidoi in Panama), or contaminated soil of animal shelters (Lu. longipalpis s.l. in South America, Phlebotomus argentipes in India; P. chinensis in China; P. ariasi, P. perfiliewi, P. perniciosus in Europe). Developmental stages of some species (P. langeroni and P. martini in Africa; P. papatasi in Eurasia; Lu. longipalpis s.l. in South America), have been found in a wide range of ecotopes, and many species of sandflies employ rodent burrows as breeding sites, although the importance of this niche is unclear. Larvae of some phlebotomines have been found in what appear to be specialized niches such as Lu. ovallesi on buttress roots of trees in Panama; P. celiae in termite hills in Kenya; P. longipes and P. pedifer in caves and among rocks in East Africa. Old World species found as immatures in

  2. RosBREED: Enabling Marker-Assisted Breeding In Rosaceae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RosBREED will create a national, dynamic, sustained effort in research, infrastructure establishment, training, and extension for applying marker-assisted breeding (MAB) to deliver improved plant materials more efficiently and rapidly. The Rosaceae family (including apple, peach, sweet and tart cher...

  3. Brain size-related breeding strategies in a seabird.

    PubMed

    Jaatinen, Kim; Öst, Markus

    2016-01-01

    The optimal compromise between decision speed and accuracy may depend on cognitive ability, associated with the degree of encephalization: larger brain size may select for accurate but slow decision-making, beneficial under challenging conditions but costly under benign ones. How this brain size-dependent selection pressure shapes avian breeding phenology and reproductive performance remains largely unexplored. We predicted that (1) large-brained individuals have a delayed breeding schedule due to thorough nest-site selection and/or prolonged resource acquisition, (2) good condition facilitates early breeding independent of relative brain size, and (3) large brain size accrues benefits mainly to individuals challenged by environmental or intrinsic constraints. To test these predictions, we examined how the relative head volume of female eiders (Somateria mollissima) of variable body condition correlated with their breeding schedule, hatching success and offspring quality. The results were consistent with our predictions. First, large head size was associated with a progressively later onset of breeding with increasing breeding dispersal distance. Second, increasing body condition advanced the timing of breeding, but this effect was significantly weaker in large-brained females. Third, larger head volume was associated with increased hatching success mainly among late breeders and those in poor body condition, and duckling body condition was positively related to maternal head volume, but only in poor-condition mothers. Our study is, to our knowledge, the first to demonstrate the presence of brain size-related differences in reproductive strategies within a single natural population. PMID:26456024

  4. [Various biological properties of Aedes cantans irides iridescent virus].

    PubMed

    Bachatskiĭ, L P; Sherban, S D

    1976-01-01

    The sedimentation coefficient, molecular weight and the type of nucleic acid of Aedes cantans iridescence virus were determined, and its proteins were analysed in a dissociating system by electrophoresis in polyacylamide gel. Ultrathin sections of affected larvae were examined. PMID:1007219

  5. Area-wide management of Aedes albopictus: lessons learned.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aedes albopictus, the Asian tiger mosquito, is the principal vector of chikungunya fever and a critical vector of dengue. This daytime biting pest often causes the majority of service requests from urban and suburban residents in New Jersey and many other states and nations where it has spread. Ou...

  6. First Record of Aedes albopictus in Sinaloa, Mexico.

    PubMed

    Torres-Avendaño, Jose I; Castillo-Ureta, Hipolito; Torres-Montoya, Edith H; Meza-Carrillo, Elizabeth; Lopez-Mendoza, Reyna L; Vazquez-Martinez, Maria G; Rendon-Maldonado, Jose G

    2015-06-01

    We report here the discovery of Aedes albopictus for the first time in Sinaloa state, Mexico. The mosquito larvae were collected from small water containers in the urban area of Culiacan city, Sinaloa state. Identification of the species was done primarily by morphology, followed by confirmation with polymerase-chain-reaction-based molecular method. PMID:26181692

  7. Cytochromr b expression and RNAi knockdown in Aedes aegypti.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cytochrome b, coded by mitochondrial DNA, is one of the cytochromes involved in the electron transport in the respiratory chain of mitochondria. Cytochrome b is a critical intermediate in mitoptosis, i.e. a mitochondrial death pathway. To reveal whether cytochrome b of the mosquito Aedes aegypti (Ae...

  8. A review on symmetries for certain Aedes aegypti models

    NASA Astrophysics Data System (ADS)

    Freire, Igor Leite; Torrisi, Mariano

    2015-04-01

    We summarize our results related with mathematical modeling of Aedes aegypti and its Lie symmetries. Moreover, some explicit, group-invariant solutions are also shown. Weak equivalence transformations of more general reaction diffusion systems are also considered. New classes of solutions are obtained.

  9. Reappearance of Aedes aegypti (Diptera: Culicidae) in Lima, Peru.

    PubMed

    Andrade, C S; Cáceres, A G; Vaquerizo, A; Ibañez-Bernal, S; Cachay, L S

    2001-07-01

    We report here the reappearance of Aedes aegypti in the Rimac district, and summarize the history of this mosquito species in Peru since its first detection in 1852. On March 17 2000 were found Ae. aegypti and Culex quinquefasciatus in Mariscal Castilla town, Flor de Amancaes, San Juan de Amancaes, El Altillo and Santa Rosa in the Rimac district, Lima Province. PMID:11500764

  10. Pyrethroid resistance is widespread among Florida populations of Aedes aegypti

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aedes aegypti is an efficient vector of a number of diseases that affect man and is of increasing concern because of the reemergence of dengue and recent identification of locally acquired chikungunya in Florida. Pesticide resistance in this species has been demonstrated in several neighboring coun...

  11. Functional development of the octenol response in aedes aegypti

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Attraction of female Aedes aegypti mosquitoes to 1-octen-3-ol (octenol), CO2, lactic acid or ammonia emitted by vertebrate hosts is not only contingent on the presence of odorants in the environment, but is also influenced by the insect’s physiological state. For anautogenous mosquito species, lik...

  12. Permethrin induces overexpression of multiple genes in Aedes aegypti.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using the PCR-select subtractive cDNA hybridization technique, 18 different genes were isolated from a permethrin-treated vs acetone-treated Aedes aegypti subtractive library. QPCR results revealed that eight of the 18 gene’s transcriptional levels in permethrin-treated Ae. aegypti were at least 2- ...

  13. Differential Susceptibilities of Aedes aegypti and Aedes albopictus from the Americas to Zika Virus

    PubMed Central

    Vazeille, Marie; Yebakima, André; Girod, Romain; Goindin, Daniella; Dupont-Rouzeyrol, Myrielle; Lourenço-de-Oliveira, Ricardo; Failloux, Anna-Bella

    2016-01-01

    Background Since the major outbreak in 2007 in the Yap Island, Zika virus (ZIKV) causing dengue-like syndromes has affected multiple islands of the South Pacific region. In May 2015, the virus was detected in Brazil and then spread through South and Central America. In December 2015, ZIKV was detected in French Guiana and Martinique. The aim of the study was to evaluate the vector competence of the mosquito spp. Aedes aegypti and Aedes albopictus from the Caribbean (Martinique, Guadeloupe), North America (southern United States), South America (Brazil, French Guiana) for the currently circulating Asian genotype of ZIKV isolated from a patient in April 2014 in New Caledonia. Methodology/Principal Findings Mosquitoes were orally exposed to an Asian genotype of ZIKV (NC-2014-5132). Upon exposure, engorged mosquitoes were maintained at 28°±1°C, a 16h:8h light:dark cycle and 80% humidity. 25–30 mosquitoes were processed at 4, 7 and 14 days post-infection (dpi). Mosquito bodies (thorax and abdomen), heads and saliva were analyzed to measure infection, dissemination and transmission, respectively. High infection but lower disseminated infection and transmission rates were observed for both Ae. aegypti and Ae. albopictus. Ae. aegypti populations from Guadeloupe and French Guiana exhibited a higher dissemination of ZIKV than the other Ae. aegypti populations examined. Transmission of ZIKV was observed in both mosquito species at 14 dpi but at a low level. Conclusions/Significance This study suggests that although susceptible to infection, Ae. aegypti and Ae. albopictus were unexpectedly low competent vectors for ZIKV. This may suggest that other factors such as the large naïve population for ZIKV and the high densities of human-biting mosquitoes contribute to the rapid spread of ZIKV during the current outbreak. PMID:26938868

  14. Larvicidal effects of various essential oils against Aedes, Anopheles, and Culex larvae (Diptera, Culicidae).

    PubMed

    Amer, Abdelkrim; Mehlhorn, Heinz

    2006-09-01

    Mosquitoes in the larval stage are attractive targets for pesticides because mosquitoes breed in water, and thus, it is easy to deal with them in this habitat. The use of conventional pesticides in the water sources, however, introduces many risks to people and/or the environment. Natural pesticides, especially those derived from plants, are more promising in this aspect. Aromatic plants and their essential oils are very important sources of many compounds that are used in different respects. In this study, the oils of 41 plants were evaluated for their effects against third-instar larvae of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. At first, the oils were surveyed against A. aegypti using a 50-ppm solution. Thirteen oils from 41 plants (camphor, thyme, amyris, lemon, cedarwood, frankincense, dill, myrtle, juniper, black pepper, verbena, helichrysum and sandalwood) induced 100% mortality after 24 h, or even after shorter periods. The best oils were tested against third-instar larvae of the three mosquito species in concentrations of 1, 10, 50, 100 and 500 ppm. The lethal concentration 50 values of these oils ranged between 1 and 101.3 ppm against A. aegypti, between 9.7 and 101.4 ppm for A. stephensi and between 1 and 50.2 ppm for C. quinquefasciatus. PMID:16642386

  15. Natural habitats of Aedes Aegypti in the Caribbean--a review.

    PubMed

    Chadee, D D; Ward, R A; Novak, R J

    1998-03-01

    Natural breeding habitats of Aedes aegypti in the Caribbean region were reviewed by conducting larval surveys in Trinidad. Puerto Rico, and the U.S. Virgin Islands and referring to records from the Mosquitoes of Middle America project. Twelve types of natural habitats were recorded: rock holes (9.7%), calabashes (2.4%), tree holes (19.5%), leaf axils (4.8%), bamboo joints (14.9%), papaya stumps (7.3%), coconut shells (4.8%), bromeliads (7.3%), ground pools (14.9%), coral rock holes (9.7%), crab holes (2.4%), and conch shells (7.3%), of which the coconut shell and calabash habitats were new to the Caribbean. The countries having the highest prevalence of natural habitats were Trinidad. Puerto Rico, and Jamaica, with 9 types (22.0%), 7 types (17.0%), and 6 types (14.6%), respectively. The distribution of natural habitats of Ae. aegypti in the Caribbean region is discussed in relation to vector control measures. PMID:9599318

  16. Use of hexaflumuron, an insect growth regulator in the control of Aedes albopictus (Skuse).

    PubMed

    Montada, D; Rajavel, A R; Vasuki, V

    1994-06-01

    An attempt was made to assess the control potency of an insect growth regulator (IGR), hexaflumuron, against Aedes albopictus, a potent dengue vector, both in the laboratory and under field conditions. Emergence inhibition activity of this IGR against laboratory reared and field collected larvae of Ae. albopictus showed EI50 values of 1.9 x 10(-4) and 1.80 x 10(-4) mg(ai)/l respectively. Under field conditions, no appreciable reduction in immature density occurred at the lowest application rate of 0.001 mg(ai)/l whereas at the rate of 0.01 mg(ai)/l 100% reduction could be seen in earthern pots placed in a garden for 9 days. A reduction of 100% in pupal density was observed for 21 and 18 days at an application rate of 0.1 mg(ai)/l in pots and tyres respectively. Considering that this IGR was effective for about three weeks, it can be used successfully at the rate of 0.1 mg(ai)/l for controlling Ae. albopictus breeding in container habitats. PMID:7855660

  17. Insecticidal action of sodium anacardate from Brazilian cashew nut shell liquid against Aedes aegypti.

    PubMed

    Farias, Davi F; Cavalheiro, Mariana G; Viana, Sayonara M; De Lima, Glauber P G; da Rocha-Bezerra, Lady Clarissa B; Ricardo, Nágila M P S; Carvalho, Ana F U

    2009-09-01

    Aedes aegypti is the major vector of 1 of the most concerning arboviruses of the world, the dengue fever. The only effective way of reducing the incidence of dengue fever is to control the vector mosquito, mainly by application of insecticides to its breeding places. This study was aimed at assessing the insecticidal activity of sodium anacardate, isolated from Brazilian cashew nut shell liquid (CNSL), against the eggs, 3rd instars or pupae of Ae. aegypti. In addition, the acute toxicity of sodium anacardate to mice was also investigated. Sodium anacardate showed toxicity against Ae. aegypti eggs (median effective concentration [EC50] = 162.93 +/- 29.93 microg/ml), larvae (median lethal concentration [LC50] = 55.47 +/- 3.0 microg/ml) and pupae (LC50 = 369.78 - 52.30 microg/ml). On the other hand, even at high dose (0.3 g/kg body weight), this compound did not cause any adverse effects on mice, suggesting that this compound is safe to mammals. Therefore, sodium anacardate may be a viable low-cost alternative to help combat Ae. aegypti. PMID:19852234

  18. Breeding, Genetics, and Cultivar Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato breeding is a challenge due to the tetraploid nature of the potato, limited variability for economically important traits in adapted breeding clones, and a complex set of requirements necessary for the successful adoption of new cultivars. However, rich germplasm resources are readily availa...

  19. THE USDA PECAN BREEDING PROGRAM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper outlines how the USDA Pecan Breeding Program is operated to produce superior new cultivars that are given names of Native American peoples, and released for planting in new pecan orchards. The USDA conducts the largest pecan breeding and genetics program in the world. The program is div...

  20. Insect-specific flaviviruses in Aedes mosquitoes in Greece.

    PubMed

    Papa, Anna; Papadopoulou, Elpida; Paliwal, Ravish; Kalaitzopoulou, Stella; Mourelatos, Spiros; Niedrig, Matthias

    2016-08-01

    Mosquitoes of the genus Aedes are known vectors of pathogenic flaviviruses, and insect-specific flaviviruses (ISFs) have been detected in members of this genus in numerous parts of the world. In order to gain insight into whether Aedes mosquitoes in Greece are infected by flaviviruses, 1173 Aedes spp. mosquitoes collected in 2010 and 2012 were grouped in 53 pools and tested by RT nested PCR using flavivirus generic primers. Eight pools (15.09 %) were found to be PCR positive: five pools (5/53, 9.4 %) contained RNA sequences related to Ochlerotatus caspius flavivirus (OCFV), an ISF previously detected in the Iberian peninsula, two pools (2/53, 3.8 %) contained sequences related to a mosquito flavivirus detected in Aedes vexans (AeveV) in Italy and the Czech Republic, and one pool contained a DNA sequence that was too short to identify accurately. The highest OCFV prevalence (12.9 %) was observed in August 2010 in the regional unit of Thessaloniki. Similar sequences were later obtained from two Culex spp. pools collected in 2013 in the same regions. A genetic difference of 0.2-1.4 % was seen among the Greek OCFV strains, which differed by 2.2-4.1 % from the Iberian strains and by 6.2-11.1 % from the Finnish Hanko virus. The genetic distances among strains varied depending on the genome region (genes for E, NS3 and NS5 proteins), with NS3 being the most variable. The present study shows no evidence of infection of Aedes mosquitoes with known pathogenic flaviviruses, but it expands the geographic distribution of OCFV in the eastern Mediterranean area. Any implication of ISFs for public health (either directly or through interactions with other flaviviruses in the mosquitoes) remains to be elucidated. PMID:27198866

  1. ITER breeding blanket design

    SciTech Connect

    Gohar, Y.; Cardella, A.; Ioki, K.; Lousteau, D.; Mohri, K.; Raffray, R.; Zolti, E.

    1995-12-31

    A breeding blanket design has been developed for ITER to provide the necessary tritium fuel to achieve the technical objectives of the Enhanced Performance Phase. It uses a ceramic breeder and water coolant for compatibility with the ITER machine design of the Basic Performance Phase. Lithium zirconate and lithium oxide am the selected ceramic breeders based on the current data base. Enriched lithium and beryllium neutron multiplier are used for both breeders. Both forms of beryllium material, blocks and pebbles are used at different blanket locations based on thermo-mechanical considerations and beryllium thickness requirements. Type 316LN austenitic steel is used as structural material similar to the shielding blanket. Design issues and required R&D data are identified during the development of the design.

  2. Truck-mounted area-wide application of pyriproxyfen targeting Aedes aegypti and Aedes albopictus in northeast Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to determine the efficacy of truck-mounted ULV applications of pyriproxyfen against Aedes aegypti larvae in artificial water containers and wild adult Ae. albopictus populations in an urban setting. The study was conducted over a 3 ½ month period (Jun – Oct 2012), during wh...

  3. Breeding latitude drives individual schedules in a trans-hemispheric migrant bird.

    PubMed

    Conklin, Jesse R; Battley, Phil F; Potter, Murray A; Fox, James W

    2010-01-01

    Despite clear benefits of optimal arrival time on breeding grounds, migration schedules may vary with an individual bird's innate quality, non-breeding habitat or breeding destination. Here, we show that for the bar-tailed godwit (Limosa lapponica baueri), a shorebird that makes the longest known non-stop migratory flights of any bird, timing of migration for individual birds from a non-breeding site in New Zealand was strongly correlated with their specific breeding latitudes in Alaska, USA, a 16,000-18,000 km journey away. Furthermore, this variation carried over even to the southbound return migration, 6 months later, with birds returning to New Zealand in approximately the same order in which they departed. These tightly scheduled movements on a global scale suggest endogenously controlled routines, with breeding site as the primary driver of temporal variation throughout the annual cycle. PMID:20842198

  4. Simultaneous DNA-based diet analysis of breeding, non-breeding and chick Adélie penguins.

    PubMed

    McInnes, Julie C; Emmerson, Louise; Southwell, Colin; Faux, Cassandra; Jarman, Simon N

    2016-01-01

    As central place foragers, breeding penguins are restricted in foraging range by the need to return to the colony to feed chicks. Furthermore, breeding birds must balance energetic gain from self-feeding with the costs of returning to provision young. Non-breeding birds, however, are likely to be less restricted in foraging range and lack the high energy demands of provisioning, therefore may consume different prey to breeders. We used DNA dietary analysis to determine whether there was a difference in provisioning and self-feeding diet by identifying prey DNA in scat samples from breeding and chick Adélie penguins at two locations in East Antarctica. We also investigated diet differences between breeders and non-breeders at one site. Although previous work shows changing foraging behaviour between chick provisioning and self-feeding, our results suggest no significant differences in the main prey groups consumed by chicks and breeders at either site or between breeding stages. This may reflect the inability of penguins to selectively forage when provisioning, or resources were sufficient for all foraging needs. Conversely, non-breeders were found to consume different prey groups to breeders, which may reflect less restricted foraging ranges, breeders actively selecting particular prey during breeding or reduced foraging experience of non-breeders. PMID:26909171

  5. Simultaneous DNA-based diet analysis of breeding, non-breeding and chick Adélie penguins

    PubMed Central

    McInnes, Julie C.; Emmerson, Louise; Southwell, Colin; Faux, Cassandra; Jarman, Simon N.

    2016-01-01

    As central place foragers, breeding penguins are restricted in foraging range by the need to return to the colony to feed chicks. Furthermore, breeding birds must balance energetic gain from self-feeding with the costs of returning to provision young. Non-breeding birds, however, are likely to be less restricted in foraging range and lack the high energy demands of provisioning, therefore may consume different prey to breeders. We used DNA dietary analysis to determine whether there was a difference in provisioning and self-feeding diet by identifying prey DNA in scat samples from breeding and chick Adélie penguins at two locations in East Antarctica. We also investigated diet differences between breeders and non-breeders at one site. Although previous work shows changing foraging behaviour between chick provisioning and self-feeding, our results suggest no significant differences in the main prey groups consumed by chicks and breeders at either site or between breeding stages. This may reflect the inability of penguins to selectively forage when provisioning, or resources were sufficient for all foraging needs. Conversely, non-breeders were found to consume different prey groups to breeders, which may reflect less restricted foraging ranges, breeders actively selecting particular prey during breeding or reduced foraging experience of non-breeders. PMID:26909171

  6. Transposition of the Hermes element in embryos of the vector mosquito, Aedes aegypti.

    PubMed

    Sarkar, A; Yardley, K; Atkinson, P W; James, A A; O'Brochta, D A

    1997-05-01

    Using a plasmid-based transpositional recombination assay in vivo, we have demonstrated that Hermes, a short inverted repeat type transposable element from Musca domestica, can transpose in Aedes aegypti embryos. Hermes transpositions in Ae. aegypti have all the characteristics observed during Hermes transposition in its host M. domestica and in related species. These characteristics include an absolute dependence on the expression of the Hermes transposase and a preference for the integration site GTNCAGAC (P < 0.05). In addition, the rate of Hermes transposition in Ae. aegypti (0.286 transpositions per 10,000 donor plasmids screened) was comparable to that observed in Drosophila melanogaster under similar conditions. These results suggest that Hermes can be developed into a gene vector and genetic engineering tool for Ae. aegypti and related mosquitoes. PMID:9219363

  7. Dispersal and survival of male and female Aedes albopictus (Diptera: Culicidae) on Réunion Island.

    PubMed

    Lacroix, R; Delatte, H; Hue, T; Reiter, P

    2009-09-01

    Mouse-baited traps were used to assess the longevity and dispersal of male and female Aedes albopictus by mark-release-recapture at two sites on La Réunion Island. Recapture rate was high, and mosquitoes of both sexes appeared up to 23 d after release. A daily survival probability of approximately 0.95 for males and females, far higher than expected, was estimated from these results. There was evidence that both sexes prefer to follow corridors of vegetation rather than crossing open spaces. Populations of wild mosquitoes had parous and insemination rates indicative of a young population. These results are relevant to future attempts to control this species by sterile insect technology. PMID:19769043

  8. A multiscaled model of southwestern willow flycatcher breeding habitat

    USGS Publications Warehouse

    Hatten, J.R.; Paradzick, C.E.

    2003-01-01

    The southwestern willow flycatcher (SWFL; Empidonax traillii extimus) is an endangered songbird whose habitat has declined dramatically over the last century. Understanding habitat selection patterns and the ability to identify potential breeding areas for the SWFL is crucial to the management and conservation of this species. We developed a multiscaled model of SWTL breeding habitat with a Geographic Information System (GIS), survey data, GIS variables, and multiple logistic regressions. We obtained presence and absence survey data from a riverine ecosystem and a reservoir delta in south-central Arizona, USA, in 1999. We extracted the GIS variables from satellite imagery and digital elevation models to characterize vegetation and floodplain within the project area. We used multiple logistic regressions within a cell-based (30 X 30 m) modeling environment to (1) determine associations between GIS variables and breeding-site occurrence at different spatial scales (0.09-72 ha), and (2) construct a predictive model. Our best model explained 54% of the variability in breeding-site occurrence with the following variables: vegetation density at the site (0.09 ha), proportion of dense vegetation and variability in vegetation density within a 4.5-ha neighborhood, and amount of floodplain or flat terrain within a 41-ha neighborhood. The density of breeding sites was highest in areas that the model predicted to be most suitable within the project area and at an external test site 200 km away. Conservation efforts must focus on protecting not only occupied patches, but also surrounding riparian forests and floodplain to ensure long-term viability of SWTL. We will use the multiscaled model to map SWTL breeding habitat in Arizona, prioritize future survey effort, and examine changes in habitat abundance and quality over time.

  9. Laboratory evaluation of two native fishes from tropical North Queensland as biological control agents of subterranean Aedes aegypti.

    PubMed

    Russell, B M; Wang, J; Williams, Y; Hearnden, M N; Kay, B H

    2001-06-01

    The ability of 2 freshwater fishes, eastern rainbow fish Melanotaenia splendida splendida and fly-specked hardyhead Craterocephalus stercusmuscarum stercusmuscarum, native to North Queensland to prey on immature Aedes aegypti was evaluated under laboratory conditions. The predation efficiency of the 2 species was compared to the exotic guppy, Poecilia reticulata, which is commonly used as a biological control agent of mosquito larvae. Of the 3 fish species tested, M. s. splendida was shown to be the most promising agent for the biological control of Ae. aegypti that breed in wells. Melanotaenia s. splendida consumed significantly greater numbers of immature Ae. aegypti than P. reticulata, irrespective of developmental stage or light conditions. Unlike C s. stercusmuscarum, M. s. splendida could be handled, transported, and kept in captivity for extended periods with negligible mortality. However, M. s. splendida was also an efficient predator of Litoria caerulea tadpoles, a species of native frog found in wells during the dry season. This result may limit the usefulness of M. s. splendida as a biological control agent of well-breeding Ae. aegypti and suggests that predacious copepods, Mesocyclops spp., are more suitable. However, the use of M. s. splendida as a mosquito control agent in containers that are unlikely to support frog populations (e.g., aquaculture tanks and drinking troughs) should be given serious consideration. PMID:11480819

  10. RosBREED: Enabling Marker-Assisted Breeding in Rosaceae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomics research has not yet been translated into routine practical application in breeding Rosaceae fruit crops (peach, apple, strawberry, cherry, apricot, pear, raspberry, etc.). Through dedicated efforts of many researchers worldwide, a wealth of genomics resources has accumulated, including ES...

  11. Mutation breeding by ion implantation

    NASA Astrophysics Data System (ADS)

    Yu, Zengliang; Deng, Jianguo; He, Jianjun; Huo, Yuping; Wu, Yuejin; Wang, Xuedong; Lui, Guifu

    1991-07-01

    Ion implantation as a new mutagenic method has been used in the rice breeding program since 1986, and for mutation breeding of other crops later. It has been shown, in principle and in practice, that this method has many outstanding advantages: lower damage rate; higher mutation rate and wider mutational spectrum. Many new lines of rice with higher yield rate; broader disease resistance; shorter growing period but higher quality have been bred from ion beam induced mutants. Some of these lines have been utilized for the intersubspecies hybridization. Several new lines of cotton, wheat and other crops are now in breeding. Some biophysical effects of ion implantation for crop seeds have been studied.

  12. Space use, migratory connectivity, and population segregation among Willets breeding in the western Great Basin

    USGS Publications Warehouse

    Haig, S.M.; Oring, L.W.; Sanzenbacher, P.M.; Taft, O.W.

    2002-01-01

    Western Willets (Catoptrophorus semipalmatus inornatus) were banded (n = 146 breeding adults and chicks) and radio-marked (n = 68 adults) at three western Great Basin wetland complexes to determine inter- and intraseasonal space use and movement patterns (primarily in 1998 and 1999). Birds were then tracked to overwintering sites where migratory connectivity and local movements were documented. Willets arrived synchronously at breeding sites during mid-April and spent less than 12 weeks in the Great Basin. There were no movements to other sites in the Great Basin during the breeding or postbreeding season. However, most breeding birds moved locally on a daily basis from upland nest sites to wetland foraging sites. The mean distance breeding birds were detected from nests did not differ between sexes or between members of a pair, although these distances were greater among postbreeding than breeding birds. Home-range estimates did not differ significantly between paired males and females during breeding or postbreeding. However, female home ranges were larger following breeding than during breeding. Shortly after chicks fledged, adult Willets left the Great Basin for locations primarily at coastal and estuarine sites in the San Francisco Bay area. Limited data revealed little among-site movements once Willets arrived at the coast, and birds appeared to be site faithful in subsequent winters. Winter sites of western Great Basin Willets differed from those used by birds from other areas in the subspecies' range, suggesting another subspecies or distinct population segment may exist. This study illustrates the importance of understanding movements and space use throughout the annual cycle in conservation planning.

  13. Space use, migratory connectivity, and population segregation among willets breeding in the western Great Basin

    USGS Publications Warehouse

    Haig, Susan M.; Oring, L.W.; Sanzenbacher, Peter; Taft, Oriane W.

    2002-01-01

    Western Willets (Catoptrophorus semipalmatus inornatus) were banded (n = 146 breeding adults and chicks) and radio-marked (n = 68 adults) at three western Great Basin wetland complexes to determine inter- and intraseasonal space use and movement patterns (primarily in 1998 and 1999). Birds were then tracked to overwintering sites where migratory connectivity and local movements were documented. Willets arrived synchronously at breeding sites during mid-April and spent less than 12 weeks in the Great Basin. There were no movements to other sites in the Great Basin during the breeding or postbreeding season. However, most breeding birds moved locally on a daily basis from upland nest sites to wetland foraging sites. The mean distance breeding birds were detected from nests did not differ between sexes or between members of a pair, although these distances were greater among postbreeding than breeding birds. Home-range estimates did not differ significantly between paired males and females during breeding or postbreeding. However, female home ranges were larger following breeding than during breeding. Shortly after chicks fledged, adult Willets left the Great Basin for locations primarily at coastal and estuarine sites in the San Francisco Bay area. Limited data revealed little among-site movements once Willets arrived at the coast, and birds appeared to be site faithful in subsequent winters. Winter sites of western Great Basin Willets differed from those used by birds from other areas in the subspecies' range, suggesting another subspecies or distinct population segment may exist. This study illustrates the importance of understanding movements and space use throughout the annual cycle in conservation planning.

  14. Best of Breed

    NASA Technical Reports Server (NTRS)

    Lohn, Jason

    2004-01-01

    No team of engineers, no matter how much time they took or how many bottles of cabernet they consumed, would dream up an antenna that looked like a deer antler on steroids. Yet that's what a group at NASA Ames Research Center came up with-thanks to a little help from Darwin. NASA's Space Technology 5 nanosatellites, which are scheduled to start measuring Earth's magnetosphere in late 2004, requires an antenna that can receive a wide range of frequencies regardless of the spacecraft's orientation. Rather than leave such exacting requirements in the hands of a human, the engineers decided to breed a design using genetic algorithms and 32 Linux PCs. The computers generated small antenna-constructing programs (the genotypes) and executed them to produce designs (the phenotypes). Then the designs were evaluated using an antenna simulator. The team settled on the form pictured here. You won't find this kind of antenna in any textbook, design guide, or research paper. But its innovative structure meets a challenging set of specifications. If successfully deployed, it will be the first evolved antenna to make it out of the lab and the first piece of evolved hardware ever to fly in space.

  15. REGIONAL DYNAMICS OF WETLAND-BREEDING FROGS AND TOADS: TURNOVER AND SYNCHRONY

    EPA Science Inventory

    We used data from a statewide frog monitoring network to investigate population turnover and synchrony in eight wetland-breeding species. We found that subpopulations at many sites turn over frequently, with breeding choruses absent or undetectable in most years. Frequencies of d...

  16. Breeding, selection, and development of potato varieties in the Eastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato breeding and variety development in the eastern U.S. is an integrated, eight-state research and extension effort. Three state breeding programs and one federal program are involved with each filling specific areas of specialization. Collaborative multi-site selection, evaluation, and variety ...

  17. Dairy Cattle: Breeding and Genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Five primary factors affect breeding genetically improved dairy cattle: 1) identification, 2) pedigree, 3) performance recording, 4) artificial insemination, and 5) genetic evaluation systems (traditional and genomic). Genetic progress can be measured as increased efficiency (higher performance with...

  18. EFFICACY OF THAI NEEM OIL AGAINST AEDES AEGYPTI (L.) LARVAE.

    PubMed

    Silapanuntakul, Suthep; Keanjoom, Romnalin; Pandii, Wongdyan; Boonchuen, Supawadee; Sombatsiri, Kwanchai

    2016-05-01

    Trees with larvicidal activity may be found in Thailand. We conducted this study to evaluate the efficacy and length of efficacy of Thai neem (Azadirachta siamensis) oil emulsion and an alginate bead of Thai neem oil formulation against early fourth stage Aedes aegypti larvae using a dipping test. The Thai neem oil emulsion had significantly greater larvicidal activity than the alginate bead formulation at 12 to 60 hours post-exposure (p < 0.01). The Thai neem oil formulation resulted in 100% mortality among the early fourth stage Aedes aegypti larvae at 48 hours, while the alginate bead formulation resulted in 98% larval mortality at 84 hours and 100% mortality at 96 hours. The mean larval mortality using the Thai neem oil emulsion dropped to < 25% by 12 days and with the alginate beads dropped to < 25% by 15 days of exposure. PMID:27405123

  19. Proteomic Identification of Dengue Virus Binding Proteins in Aedes aegypti Mosquitoes and Aedes albopictus Cells

    PubMed Central

    Muñoz, Maria de Lourdes; Limón-Camacho, Gustavo; Tovar, Rosalinda; Diaz-Badillo, Alvaro; Mendoza-Hernández, Guillermo; Black, William C.

    2013-01-01

    The main vector of dengue in America is the mosquito Aedes aegypti, which is infected by dengue virus (DENV) through receptors of midgut epithelial cells. The envelope protein (E) of dengue virus binds to receptors present on the host cells through its domain III that has been primarily recognized to bind cell receptors. In order to identify potential receptors, proteins from mosquito midgut tissue and C6/36 cells were purified by affinity using columns with the recombinant E protein domain III (rE-DIII) or DENV particles bound covalently to Sepharose 4B to compare and evaluate their performance to bind proteins including putative receptors from female mosquitoes of Ae. aegypti. To determine their identity mass spectrometric analysis of purified proteins separated by polyacrylamide gel electrophoresis was performed. Our results indicate that both viral particles and rE-DIII bound proteins with the same apparent molecular weights of 57 and 67 kDa. In addition, viral particles bound high molecular weight proteins. Purified proteins identified were enolase, beta-adrenergic receptor kinase (beta-ARK), translation elongation factor EF-1 alpha/Tu, and cadherin. PMID:24324976

  20. Genetic analysis of seven Italian horse breeds based on mitochondrial DNA D-loop variation.

    PubMed

    Bigi, D; Perrotta, G; Zambonelli, P

    2014-08-01

    To understand the origin and genetic diversity of Italian horses, mitochondrial DNA D-loop sequences were generated for 163 horses from seven breeds. Sequence analysis of a 480-bp segment revealed a total of 84 haplotypes with 57 polymorphic sites, indicating multiple maternal origins and high genetic diversity. Comparison of the haplotypes with the equine mtDNA haplotype/haplogroup nomenclature showed a haplogroup distribution in the Italian breeds more similar to that found in the Middle East breeds than in the European breeds, probably due to the economic and cultural relationship with the Middle East in the past centuries. PMID:24702170

  1. Field evaluation of Bacillus thuringiensis H-14 against Aedes mosquitoes.

    PubMed

    Lee, Y W; Zairi, J

    2006-06-01

    Studies were carried out on the residual efficacy of Bacillus thuringiensis H-14 (water dispersible granule, VectoBac ABG 6511) as direct application in the control of Aedes larvae in the field. Field Aedes sp populations in the earthen and glass jars were predetermined before initiation of the trial. On confirmation of the presence of Aedes species in the designated area, Sungai Nibong Kecil, Penang Island, Malaysia, Bti was introduced in the 55L earthen and 3L glass jars). Two test designs were carried out. The first design had treated water replenished daily with 6L of seasoned water and the second design is without the replenishment of water but evaporated water was replenished. Bti was effective in the field for at least 35 days with more than 80% reduction in the Aedes larvae in the treated containers. For earthen jars with daily replenishment of water, 100% reduction was recorded for the first 3 days, while more than 80% reduction was recorded up to day 40. At day 60, Bti still provided an efficacy of 54.32 +/- 4.61 (%) of reduction. Whilst for earthen jars without daily replenishment of water, 100% reduction was recorded for the first 5 days, while more than 80% of reduction was recorded up to day 40. For the glass jars studied, similar efficacy was observed. In jars with daily replenishment of water a better larval control was observed. Percentage of reduction from day 50 to 60 for replenishment of water was between 50 to 70% compared to without replenishment of water with less than 40%. PMID:17041550

  2. Intraspecific Competition and Population Dynamics of Aedes aegypti

    NASA Astrophysics Data System (ADS)

    Paixão, C. A.; Charret, I. C.; Lima, R. R.

    2012-04-01

    We report computational simulations for the evolution of the population of the dengue vector, Aedes aegypti mosquitoes. The results suggest that controlling the mosquito population, on the basis of intraspecific competition at the larval stage, can be an efficient mechanism for controlling the spread of the epidemic. The results also show the presence of a kind of genetic evolution in vector population, which results mainly in increasing the average lifespan of individuals in adulthood.

  3. Similarity solutions for systems arising from an Aedes aegypti model

    NASA Astrophysics Data System (ADS)

    Freire, Igor Leite; Torrisi, Mariano

    2014-04-01

    In a recent paper a new model for the Aedes aegypti mosquito dispersal dynamics was proposed and its Lie point symmetries were investigated. According to the carried group classification, the maximal symmetry Lie algebra of the nonlinear cases is reached whenever the advection term vanishes. In this work we analyze the family of systems obtained when the wind effects on the proposed model are neglected. Wide new classes of solutions to the systems under consideration are obtained.

  4. An adulticidal sticky ovitrap for sampling container-breeding mosquitoes.

    PubMed

    Ritchie, Scott A; Long, Sharron; Hart, Alistair; Webb, Cameron E; Russell, Richard C

    2003-09-01

    The efficacy of a standard ovitrap and an ovitrap featuring an internal wall covered by a polybutylene adhesive was compared in field studies in Cairns, Australia. The sticky ovitrap was as effective as the standard ovitrap in detecting Aedes aegypti, with 67.5% and 64% of traps positive for Ae. aegypti, respectively. Significantly higher numbers of Ae. aegypti were collected by traps set outside rather than inside premises. Sticky ovitraps also readily collected Ochlerotatus notoscriptus and, especially, Culex quinquefasciatus. With a 10X hand lens, mosquitoes of these species could readily be identified in traps set for 3 and 7 days. The sticky ovitraps were comparable in cost and as time efficient as standard ovitraps. The greatest advantage of the sticky ovitrap is the collection of adult female mosquitoes, negating the need to rear larvae for identification and providing a faster, more direct measure of the effectiveness of ovipositional attractants than egg counts. Finally, we demonstrated that sticky ovitraps, being adulticidal, have potential as a supplementary control measure, especially for quarantine programs designed to prevent the import and export of container-breeding vector mosquitoes at sea- and airports. PMID:14524545

  5. Control methods against invasive Aedes mosquitoes in Europe: a review.

    PubMed

    Baldacchino, Frédéric; Caputo, Beniamino; Chandre, Fabrice; Drago, Andrea; della Torre, Alessandra; Montarsi, Fabrizio; Rizzoli, Annapaola

    2015-11-01

    Five species of invasive Aedes mosquitoes have recently become established in Europe: Ae. albopictus, Ae. aegypti, Ae. japonicus japonicus, Ae. koreicus and Ae. atropalpus. These mosquitoes are a serious nuisance for people and are also competent vectors for several exotic pathogens such as dengue and chikungunya viruses. As they are a growing public health concern, methods to control these mosquitoes need to be implemented to reduce their biting and their potential for disease transmission. There is a crucial need to evaluate methods as part of an integrated invasive mosquito species control strategy in different European countries, taking into account local Aedes infestations and European regulations. This review presents the control methods available or in development against invasive Aedes mosquitoes, with a particular focus on those that can be implemented in Europe. These control methods are divided into five categories: environmental (source reduction), mechanical (trapping), biological (e.g. copepods, Bacillus thuringiensis var. israelensis, Wolbachia), chemical (insect growth regulators, pyrethroids) and genetic (sterile insect technique and genetically modified mosquitoes). We discuss the effectiveness, ecological impact, sustainability and stage of development of each control method. PMID:26037532

  6. Changing nest placement of Hawaiian Common Amakihi during the breeding cycle

    USGS Publications Warehouse

    van Riper, Charles, III; Kern, M. D.; Sogge, M. K.

    1993-01-01

    We studied the nesting behavior of the Common Amakihi (Hemignathus virens) from 1970-1981 on the island of Hawaii to determine if the species alters nest placement over a protracted 9-month breeding season. Birds preferentially chose the southwest quadrant of trees in which to build nests during all phases of the breeding season. It appeared that ambient temperature (Ta) was a contributing factor to differential nest placement between early and late phases of the annual breeding cycle. When Ta is low during the early (December-March) breeding period, Common Amakihi selected exposed nesting locations that benefitted them with maximum solar insolation. However, in the later phase of the breeding period (April-July) when Ta was much higher, renesting birds selected nest sites deeper in the canopy in significantly taller trees. This is one of the few documented examples in which a species changes location of nest during a breeding season, thus allowing exploitation of temporally differing microclimatic conditions.

  7. Interspecific Cross-Mating Between Aedes aegypti and Aedes albopictus Laboratory Strains: Implication of Population Density on Mating Behaviors.

    PubMed

    Marcela, P; Hassan, A Abu; Hamdan, A; Dieng, H; Kumara, T K

    2015-12-01

    Mating behavior between Aedes aegypti and Ae. albopictus, established colony strains were examined under laboratory conditions (30-cm(3) screened cages) for 5 consecutive days. The effect of selected male densities (30, 20, 10) and female density (20) on the number of swarming, mating pairs, eggs produced, and inseminated females were evaluated. Male densities significantly increased swarming behavior, mating pairs, and egg production of heterospecific females, but female insemination was reduced. Aedes aegypti males mate more readily with heterospecific females than do Ae. albopictus males. The current study suggests that Ae. aegypti males were not species-specific in mating, and if released into the field as practiced in genetically modified mosquito techniques, they may mate with both Ae. aegypti and Ae. albopictus females, hence reducing populations of both species by producing infertile eggs. PMID:26675452

  8. Modelling the ecology of the coastal mosquitoes Aedes vigilax and Aedes camptorhynchus at Port Pirie, South Australia.

    PubMed

    Kokkinn, M J; Duval, D J; Williams, C R

    2009-03-01

    Two mosquito species, Aedes camptorhynchus (Thomson) and Aedes vigilax (Skuse) (Diptera: Culicidae) are responsible for significant nuisance biting and disease transmission in southern coastal Australia. Mosquito abundance, tide height, temperature and rainfall data were collected over three summer seasons (2002, 2003, 2004) at Port Pirie, South Australia and subjected to statistical analysis to develop ecological models for predicting problem mosquito outbreaks. A logistic regression model for Ae. camptorhynchus gave a predictive R(2) of 0.30 using mean air temperature, whereas, for Ae. vigilax, tide height, mean air temperature and day length yielded a regression with an R(2) of 0.68. These models identify significant environmental drivers for both species and may be useful in the prediction of future outbreaks, particularly of Ae. vigilax. PMID:19239618

  9. Eggshells as an index of aedine mosquito production. 1: Distribution, movement and sampling of Aedes taeniorhynchus eggshells.

    PubMed

    Ritchie, S A; Addison, D S; van Essen, F

    1992-03-01

    The distribution of Aedes taeniorhynchus eggshells in Florida mangrove basin forests was determined and used to design a sampling plan. Eggshells were found in 10/11 sites (91%), with a mean +/- SE density of 1.45 +/- 0.75/cc; density did not change significantly year to year. Highest densities were located on the sloping banks of hummocks, ponds and potholes. Eggshells were less clumped in distribution than eggs and larvae and thus required a smaller sample size for a given precision level. While eggshells were flushed from compact soil that was subject to runoff during heavy rain, mangrove peat, the dominant soil of eggshell-bearing sites, was less dense and had little runoff or eggshell flushing. We suggest that eggshell surveys could be used to identify Ae. taeniorhynchus oviposition sites and oviposition patterns. PMID:1583486

  10. Transcription of detoxification genes after permethrin selection in the mosquito Aedes aegypti.

    PubMed

    Saavedra-Rodriguez, K; Suarez, A F; Salas, I F; Strode, C; Ranson, H; Hemingway, J; Black, William C

    2012-02-01

    Changes in gene expression before, during and after five generations of permethrin laboratory selection were monitored in six strains of Aedes aegypti: five F(2)-F(3) collections from the Yucatán Peninsula of Mexico and one F(2) from Iquitos, Peru. Three biological replicate lines were generated for each strain. The response to selection was measured as changes in the lethal and knockdown permethrin concentrations (LC(50), KC(50)) and in the frequency of the Ile1,016 substitution in the voltage-gated sodium channel (para) gene. Changes in expression of 290 metabolic detoxification genes were measured using the 'Aedes Detox' microarray. Selection simultaneously increased the LC(50), KC(50) and Ile1,016 frequency. There was an inverse relationship between Ile1,016 frequency and the numbers of differentially transcribed genes. The Iquitos strain lacked the Ile1,016 allele and 51 genes were differentially transcribed after selection as compared with 10-18 genes in the Mexican strains. Very few of the same genes were differentially transcribed among field strains but 10 cytochrome P(450) genes were upregulated in more than one strain. Laboratory adaptation to permethrin in Ae. aegypti is genetically complex and largely conditioned by geographic origin and pre-existing target site insensitivity in the para gene. The lack of uniformity in the genes that responded to artificial selection as well as differences in the direction of their responses challenges the assumption that one or a few genes control permethrin metabolic resistance. Attempts to identify one or a few metabolic genes that are predictably associated with permethrin adaptation may be futile. PMID:22032702

  11. Deltamethrin Resistance Mechanisms in Aedes aegypti Populations from Three French Overseas Territories Worldwide

    PubMed Central

    Dusfour, Isabelle; Zorrilla, Pilar; Guidez, Amandine; Issaly, Jean; Girod, Romain; Guillaumot, Laurent; Robello, Carlos; Strode, Clare

    2015-01-01

    Background Aedes aegypti is a cosmopolite mosquito, vector of arboviruses. The worldwide studies of its insecticide resistance have demonstrated a strong loss of susceptibility to pyrethroids, the major class of insecticide used for vector control. French overseas territories such as French Guiana (South America), Guadeloupe islands (Lesser Antilles) as well as New Caledonia (Pacific Ocean), have encountered such resistance. Methodology/Principal Findings We initiated a research program on the pyrethroid resistance in French Guiana, Guadeloupe and New Caledonia. Aedes aegypti populations were tested for their deltamethrin resistance level then screened by an improved microarray developed to specifically study metabolic resistance mechanisms. Cytochrome P450 genes were implicated in conferring resistance. CYP6BB2, CYP6M11, CYP6N12, CYP9J9, CYP9J10 and CCE3 genes were upregulated in the resistant populations and were common to other populations at a regional scale. The implication of these genes in resistance phenomenon is therefore strongly suggested. Other genes from detoxification pathways were also differentially regulated. Screening for target site mutations on the voltage-gated sodium channel gene demonstrated the presence of I1016 and C1534. Conclusion /significance This study highlighted the presence of a common set of differentially up-regulated detoxifying genes, mainly cytochrome P450 genes in all three populations. GUA and GUY populations shared a higher number of those genes compared to CAL. Two kdr mutations well known to be associated to pyrethroid resistance were also detected in those two populations but not in CAL. Different selective pressures and genetic backgrounds can explain such differences. These results are also compared with those obtained from other parts of the world and are discussed in the context of integrative research on vector competence. PMID:26588076

  12. Transcription of detoxification genes following permethrin selection in the mosquito Aedes aegypti

    PubMed Central

    Saavedra-Rodriguez, Karla; Suarez, Adriana Flores; Salas, Ildefonso Fernandez; Strode, Clare; Ranson, Hilary; Hemingway, Janet; Black, William C.

    2011-01-01

    Changes in gene expression before, during and after five generations of permethrin laboratory selection were monitored in six strains of Aedes aegypti: five F2 – F3 collections from the Yucatán Peninsula of México and one F2 from Iquitos, Perú. Three biological replicate lines were generated for each strain. The response to selection was measured as changes in the lethal and knockdown permethrin concentrations (LC50, KC50) and in the frequency of the Ile1,016 substitution in the voltage gated sodium channel (para) gene. Changes in expression of 290 metabolic detoxification genes were measured using the “Aedes Detox” microarray. Selection simultaneously increased the LC50, KC50 and Ile1,016 frequency. There was an inverse relationship between Ile1,016 frequency and the numbers of differentially transcribed genes. The Iquitos strain lacked the Ile1,016 allele and 51 genes were differentially transcribed following selection as compared to 10–18 genes in the Mexican strains. Very few of the same genes were differentially transcribed among field strains but ten cytochrome P450 genes were upregulated in more than one strain. Laboratory adaptation to permethrin in Ae. aegypti is genetically complex and largely conditioned by geographic origin and preexisting target site insensitivity in the para gene. The lack of uniformity in the genes that responded to artificial selection as well as differences in the direction of their responses challenges the assumption that one or a few genes control permethrin metabolic resistance. Attempts to identify one or a few metabolic genes that are predictably associated with permethrin adaptation may be futile. PMID:22032702

  13. Long-term surveillance data and patterns of invasion by Aedes albopictus in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We used GIS and long-term mosquito surveillance data from Lake County, Pasco County, Manatee County, and Sarasota County, Florida to look at patterns of invasion by Aedes albopictus with respect to changes in populations of resident Aedes aegypti. We investigated associations of rainfall with chang...

  14. Mitochondrial markers to distinguish two species of Aedes Neomelaniconion (Diptera: Culicidae) from Kenya

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aedes mcintoshi and Ae circumluteolus are two common flood water mosquito species collected in Kenya. Both belong to the Aedes subgenus Neomelaniconion, a relatively large subgenus with representative species in the Ethiopian, Oriental, Australian and Palearctic regions. In Kenya, both have been imp...

  15. Phylogenetic Relationships of the Mangalitsa Swine Breed Inferred from Mitochondrial DNA Variation

    PubMed Central

    Georgescu, Sergiu Emil; Manea, Maria Adina; Dudu, Andreea; Costache, Marieta

    2012-01-01

    The Mangalitsa pig, a swine breed belonging to the protected gene fund of original and primitive animal breeds of the FAO (Food and Agriculture Organization), has been known to inhabit Romanian territories since the 19th century. The aim of this study was to compare the Mangalitsa breed with several European and Asiatic swine breeds in order to emphasize its uniqueness and to elucidate its origin. For this purpose, we analyzed a 613 bp mitochondrial DNA D-loop fragment and 1140 bp of the cytochrome b gene in a population of Mangalitsa pigs and the polymorphic sites were compared with sequences from GenBank originating from other swine breeds. Taking into account the total of 24 breeds and 5 different Wild Boar populations analyzed, 86 polymorphic sites representing 32 haplotypes were observed, with an average percentage of polymorphic sites of 4.9%. Three Neighbor-Joining phylogenetic trees were constructed based on Kimura 2-parameter distances, using D-loop, cytochrome b and mitochondrial reunited sequences. For the analyzed Mangalitsa population, four distinct haplotypes were identified, including one that was common to other breeds. Our study suggests that the Mangalitsa swine originate from primitive breeds which might be directly derived from the Wild Boar. PMID:22942714

  16. Specific detection of the floodwater mosquitoes Aedes sticticus and Aedes vexans DNA in predatory diving beetles.

    PubMed

    Vinnersten, Thomas Z Persson; Halvarsson, Peter; Lundström, Jan O

    2015-08-01

    Floodwater mosquitoes (Diptera: Culicidae) are associated with periodically flooded wet meadows, marshes, and swamps in floodplains of major rivers worldwide, and their larvae are abundant in the shallow parts of flooded areas. The nuisance caused by the blood-seeking adult female mosquitoes motivates mosquito control. Larviciding with Bacillus thuringiensis israelensis is considered the most environmentally safe method. However, some concern has been raised whether aquatic predatory insects could be indirectly affected by this reduction in a potential vital prey. Top predators in the temporary wetlands in the River Dalälven floodplains are diving beetles (Coleoptera: Dytiscidae), and Aedes sticticus and Ae. vexans are the target species for mosquito control. For detailed studies on this aquatic predator-prey system, we developed a polymerase chain reaction (PCR) assay for detection of mosquito DNA in the guts of medium-sized diving beetles. Primers were designed for amplifying short mitochondrial DNA fragments of the cytochrome C oxidase subunit I (COI) gene in Ae. sticticus and Ae. vexans, respectively. Primer specificity was confirmed and half-life detectability of Ae. sticticus DNA in diving beetle guts was derived from a feeding and digestion experiment. The Ae. sticticus DNA within diving beetle guts was detected up to 12 h postfeeding, and half-life detectability was estimated to 5.6 h. In addition, field caught diving beetles were screened for Ae. sticticus and Ae. vexans DNA and in 14% of the diving beetles one or both mosquito species were detected, showing that these mosquito species are utilized as food by the diving beetles. PMID:24895318

  17. Vector Competence of Aedes aegypti and Aedes polynesiensis Populations from French Polynesia for Chikungunya Virus

    PubMed Central

    Richard, Vaea; Paoaafaite, Tuterarii; Cao-Lormeau, Van-Mai

    2016-01-01

    Background From October 2014 to March 2015, French Polynesia experienced for the first time a chikungunya outbreak. Two Aedes mosquitoes may have contributed to chikungunya virus (CHIKV) transmission in French Polynesia: the worldwide distributed Ae. aegypti and the Polynesian islands-endemic Ae. polynesiensis mosquito. Methods To investigate the vector competence of French Polynesian populations of Ae. aegypti and Ae. polynesiensis for CHIKV, mosquitoes were exposed per os at viral titers of 7 logs tissue culture infectious dose 50%. At 2, 6, 9, 14 and 21 days post-infection (dpi), saliva was collected from each mosquito and inoculated onto C6/36 mosquito cells to check for the presence of CHIKV infectious particles. Legs and body (thorax and abdomen) of each mosquito were also collected at the different dpi and submitted separately to viral RNA extraction and CHIKV real-time RT-PCR. Results CHIKV infection rate, dissemination and transmission efficiencies ranged from 7–90%, 18–78% and 5–53% respectively for Ae. aegypti and from 39–41%, 3–17% and 0–14% respectively for Ae. polynesiensis, depending on the dpi. Infectious saliva was found as early as 2 dpi for Ae. aegypti and from 6 dpi for Ae. polynesiensis. Our laboratory results confirm that the French Polynesian population of Ae. aegypti is highly competent for CHIKV and they provide clear evidence for Ae. polynesiensis to act as an efficient CHIKV vector. Conclusion As supported by our findings, the presence of two CHIKV competent vectors in French Polynesia certainly contributed to enabling this virus to quickly disseminate from the urban/peri-urban areas colonized by Ae. aegypti to the most remote atolls where Ae. polynesiensis is predominating. Ae. polynesiensis was probably involved in the recent chikungunya outbreaks in Samoa and the Cook Islands. Moreover, this vector may contribute to the risk for CHIKV to emerge in other Polynesian islands like Fiji, and more particularly Wallis where there

  18. Cassava Breeding I: The Value of Breeding Value

    PubMed Central

    Ceballos, Hernán; Pérez, Juan C.; Joaqui Barandica, Orlando; Lenis, Jorge I.; Morante, Nelson; Calle, Fernando; Pino, Lizbeth; Hershey, Clair H.

    2016-01-01

    Breeding cassava relies on several selection stages (single row trial-SRT; preliminary; advanced; and uniform yield trials—UYT). This study uses data from 14 years of evaluations. From more than 20,000 genotypes initially evaluated only 114 reached the last stage. The objective was to assess how the data at SRT could be used to predict the probabilities of genotypes reaching the UYT. Phenotypic data from each genotype at SRT was integrated into the selection index (SIN) used by the cassava breeding program. Average SIN from all the progenies derived from each progenitor was then obtained. Average SIN is an approximation of the breeding value of each progenitor. Data clearly suggested that some genotypes were better progenitors than others (e.g., high number of their progenies reaching the UYT), suggesting important variation in breeding values of progenitors. However, regression of average SIN of each parental genotype on the number of their respective progenies reaching UYT resulted in a negligible coefficient of determination (r2 = 0.05). Breeding value (e.g., average SIN) at SRT was not efficient predicting which genotypes were more likely to reach the UYT stage. Number of families and progenies derived from a given progenitor were more efficient predicting the probabilities of the progeny from a given parent reaching the UYT stage. Large within-family genetic variation tends to mask the true breeding value of each progenitor. The use of partially inbred progenitors (e.g., S1 or S2 genotypes) would reduce the within-family genetic variation thus making the assessment of breeding value more accurate. Moreover, partial inbreeding of progenitors can improve the breeding value of the original (S0) parental material and sharply accelerate genetic gains. For instance, homozygous S1 genotypes for the dominant resistance to cassava mosaic disease (CMD) could be generated and selected. All gametes from these selected S1 genotypes would carry the desirable allele and

  19. Cassava Breeding I: The Value of Breeding Value.

    PubMed

    Ceballos, Hernán; Pérez, Juan C; Joaqui Barandica, Orlando; Lenis, Jorge I; Morante, Nelson; Calle, Fernando; Pino, Lizbeth; Hershey, Clair H

    2016-01-01

    Breeding cassava relies on several selection stages (single row trial-SRT; preliminary; advanced; and uniform yield trials-UYT). This study uses data from 14 years of evaluations. From more than 20,000 genotypes initially evaluated only 114 reached the last stage. The objective was to assess how the data at SRT could be used to predict the probabilities of genotypes reaching the UYT. Phenotypic data from each genotype at SRT was integrated into the selection index (SIN) used by the cassava breeding program. Average SIN from all the progenies derived from each progenitor was then obtained. Average SIN is an approximation of the breeding value of each progenitor. Data clearly suggested that some genotypes were better progenitors than others (e.g., high number of their progenies reaching the UYT), suggesting important variation in breeding values of progenitors. However, regression of average SIN of each parental genotype on the number of their respective progenies reaching UYT resulted in a negligible coefficient of determination (r (2) = 0.05). Breeding value (e.g., average SIN) at SRT was not efficient predicting which genotypes were more likely to reach the UYT stage. Number of families and progenies derived from a given progenitor were more efficient predicting the probabilities of the progeny from a given parent reaching the UYT stage. Large within-family genetic variation tends to mask the true breeding value of each progenitor. The use of partially inbred progenitors (e.g., S1 or S2 genotypes) would reduce the within-family genetic variation thus making the assessment of breeding value more accurate. Moreover, partial inbreeding of progenitors can improve the breeding value of the original (S0) parental material and sharply accelerate genetic gains. For instance, homozygous S1 genotypes for the dominant resistance to cassava mosaic disease (CMD) could be generated and selected. All gametes from these selected S1 genotypes would carry the desirable allele and

  20. Breeding potential of elite Pee Dee germplasm in Upland cotton breeding programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Successful plant breeding programs begin with parental line selection. Effective parental line selection is facilitated when the breeding potential of candidate parental lines is known. Using topcross families involving germplasm representing eight US public cotton breeding programs, we evaluated th...

  1. Previous success and current body condition determine breeding propensity in Lesser Scaup: evidence for the individual heterogeneity hypothesis

    USGS Publications Warehouse

    Warren, Jeffrey M.; Cutting, Kyle A.; Takekawa, John Y.; De La Cruz, Susan E. W.; Williams, Tony D.; Koons, David N.

    2014-01-01

    The decision to breed influences an individual's current and future reproduction, and the proportion of individuals that breed is an important determinant of population dynamics. Age, experience, individual quality, and environmental conditions have all been demonstrated to influence breeding propensity. To elucidate which of these factors exerts the greatest influence on breeding propensity in a temperate waterfowl, we studied female Lesser Scaup (Aythya affinis) breeding in southwestern Montana. Females were captured during the breeding seasons of 2007–2009, and breeding status was determined on the basis of (1) presence of an egg in the oviduct or (2) blood plasma vitellogenin (VTG) levels. Presence on the study site in the previous year, a proxy for adult female success, was determined with stable isotope signatures of a primary feather collected at capture. Overall, 57% of females had evidence of breeding at the time of capture; this increased to 86% for females captured on or after peak nest initiation. Capture date and size-adjusted body condition positively influenced breeding propensity, with a declining body-condition threshold through the breeding season. We did not detect an influence of age on breeding propensity. Drought conditions negatively affected breeding propensity, reducing the proportion of breeding females to 0.85 (SE = 0.05) from 0.94 (SE = 0.03) during normal-water years. A female that was present in the previous breeding season was 5% more likely to breed than a female that was not present then. The positive correlation between age and experience makes it difficult to differentiate the roles of age, experience, and individual quality in reproductive success in vertebrates. Our results indicate that individual quality, as expressed by previous success and current body condition, may be among the most important determinants of breeding propensity in female Lesser Scaup, providing further support for the individual heterogeneity hypothesis.

  2. Introduction and potential establishment of Aedes albopictus in California in 2001.

    PubMed

    Linthicum, Kenneth J; Kramer, Vicki L; Madon, Minoo B; Fujioka, Kenn

    2003-12-01

    Aedes albopictus was discovered in Los Angeles, California, in June 2001 in a maritime cargo container from China containing a shipment of a commercial plant product known as "Lucky Bamboo" (Dracaena spp.). To keep the plants alive during the ocean transit, they were shipped in 5-8 cm of water, providing an excellent habitat for Ae. albopictus. Mosquito infestations were subsequently detected at 15 nursery distributors of Dracaena in 2 northern and 4 southern California counties. The distribution of the Ae. albopictus infestations was limited to the vicinity of those nursery distributors with documented infestations. Infestations persisted for more than 5 months near some of the nurseries, and eggs were found in ovitraps until mid-November 2001 up to 1,000 m from the original infestation sites. Overwintering Ae. albopictus populations were discovered in April, July, and August 2002 at original infestation sites in Chino, San Bernardino County, and Monterey Park and Rowland Heights, Los Angeles County, respectively. Specimens were found at some sites of overwintering populations until October 2002. PMID:14710730

  3. Diet of canvasbacks during breeding

    USGS Publications Warehouse

    Austin, J.E.; Serie, J.R.; Noyes, J.H.

    1990-01-01

    We examined diets of canvasbacks (Aythya valisineria) breeding in southwestern Manitoba during 1977-81. Percent volume of animal foods consumed did not differ between males and females nor among prenesting, rapid follicle growth, laying, incubation, and renesting periods in females (mean = 50.1%). Tubers and shoots of fennelleaf pondweed (Potamogeton pectinatus) and midge larvae (Chironomidae) were the predominant foods, comprising on average 45% and 23% of the diet volume, respectively. Continued importance of plant foods to canvasbacks throughout reproduction contrasts with the mostly invertebrate diets of other prairie-breeding ducks, and does not fit current theories of nutritional ecology of breeding anatids (i.e., females meet the protein requirements of reproduction by consuming a high proportion of animal foods).

  4. Monitoring Temporal Abundance and Spatial Distribution of Aedes polynesiensis Using BG-Sentinel Traps in Neighboring Habitats on Raiatea, Society Archipelago, French Polynesia

    PubMed Central

    MERCER, DAVID R.; BOSSIN, HERVE; SANG, MICHEL CHEONG; O’CONNOR, LINDA; DOBSON, STEPHEN L.

    2012-01-01

    Adult numbers and sizes of mosquitoes were monitored for 2 yr in neighboring habitats on the western coast of Raiatea (Society Archipelago) in anticipation of testing new vector control technologies. Aedes polynesiensis Marks females comprised the overwhelming majority (≈99%) of the three species of mosquitoes captured in Biogent Sentinel traps placed at fixed sites on three small satellite islands (motus) of the western lagoon and on the shoreline of Raiatea. Aedes polynesiensis males, Aedes aegypti (L.), and Culex quinquefasciatus Say rarely were collected. Numbers of Ae. polynesiensis females per collection differed among trapping dates and locations, with the majority of females captured on two motus, Horea and Toamaro. Shoreline and Horea females had significantly longer mean wing lengths than females from Tiano and Toamaro. Thus, wing lengths were influenced more by local developmental conditions than overall numbers of adults. Significantly more females were captured during the wet season than the dry season. Nonetheless, at least on the two highly productive motus, dry-season females had larger wing lengths than their wet season counterparts. Local weather patterns predicted about half the variation in mosquito numbers. Differences in vector abundance observed when comparing neighboring motus are likely because of differences in human activity and mosquito suppression. PMID:22308771

  5. Insensitivity to the Spatial Repellent Action of Transfluthrin in Aedes aegypti: A Heritable Trait Associated with Decreased Insecticide Susceptibility

    PubMed Central

    Wagman, Joseph M.; Achee, Nicole L.; Grieco, John P.

    2015-01-01

    Background New vector control paradigms expanding the use of spatial repellents are promising, but there are many gaps in our knowledge about how repellents work and how their long-term use might affect vector populations over time. Reported here are findings from a series of in vitro studies that investigated the plasticity and heritability of spatial repellent (SR) behaviors in Aedes aegypti exposed to airborne transfluthrin, including results that indicate a possible link between repellent insensitivity and insecticide resistance. Methodology/principal findings A dual-choice chamber system was used to observe directional flight behaviors in Aedes aegypti mosquitoes exposed to passively emanating transfluthrin vapors (1.35 mg/m3). Individual SR responder and SR non-responder mosquitoes were identified, collected and maintained separately according to their observed phenotype. Subsequent testing included re-evaluation of behavioral responses in some mosquito cohorts as well as testing the progeny of selectively bred responder and non-responder mosquito strains through nine generations. At baseline (F0 generation), transfluthrin actively repelled mosquitoes in the assay system. F0 mosquitoes repelled upon initial exposure to transfluthrin vapors were no more likely to be repelled again by subsequent exposure 24h later, but repelled mosquitoes allowed to rest for 48h were subsequently repelled at a higher proportion than was observed at baseline. Selective breeding of SR responders for nine generations did not change the proportion of mosquitoes repelled in any generation. However, selective breeding of SR non-responders did produce, after four generations, a strain of mosquitoes that was insensitive to the SR activity of transfluthrin. Compared to the SR responder strain, the SR insensitive strain also demonstrated decreased susceptibility to transfluthrin toxicity in CDC bottle bioassays and a higher frequency of the V1016Ikdr mutation. Conclusions/significance SR

  6. Essential oils and their compounds as Aedes aegypti L. (Diptera: Culicidae) larvicides: review.

    PubMed

    Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho

    2014-02-01

    This review aims to describe essential oils and their constituent compounds that exhibit bioactivity against Aedes aegypti L. (Diptera: Culicidae) larvae, the immature stage of the primary vector of dengue. This review is based on original articles obtained by searching on major databases. Our literature review revealed that 361 essential oils from 269 plant species have been tested for their larvicidal activity. More than 60 % of these essential oils were considered active (LC50<100 mg/L), and the majority of these active oils were derived from species belonging to Myrtaceae, Lamiaceae, and Rutaceae. The most active essential oils exhibited effective concentrations comparable with the dosage recommended for the use of temephos in container breeding. Approximately 27 % of the plants studied for their larvicidal activity against A. aegypti were collected in Brazil. Essential oils rich in phenylpropanoids, oxygenated sesquiterpenes, and monoterpene hydrocarbons were found to be the most active. When the isolates were tested, phenylpropanoids and monoterpene hydrocarbons were the most active compound classes. We describe the plant parts used and the major constituents of the essential oils. In addition, we discuss factors affecting the activity (such as plant parts, age of the plant, chemotypes, larval source, and methods used), structure-activity relationships, and mechanisms of action of the essential oils and their compounds. Essential oils have been widely investigated and show high larvicidal activity against A. aegypti. This review reveals that the essential oils are effective alternatives for the production of larvicides, which can be used in vector-borne disease control programmes. PMID:24265058

  7. Comparison of molecular breeding values based on within- and across-breed training in beef cattle

    PubMed Central

    2013-01-01

    Background Although the efficacy of genomic predictors based on within-breed training looks promising, it is necessary to develop and evaluate across-breed predictors for the technology to be fully applied in the beef industry. The efficacies of genomic predictors trained in one breed and utilized to predict genetic merit in differing breeds based on simulation studies have been reported, as have the efficacies of predictors trained using data from multiple breeds to predict the genetic merit of purebreds. However, comparable studies using beef cattle field data have not been reported. Methods Molecular breeding values for weaning and yearling weight were derived and evaluated using a database containing BovineSNP50 genotypes for 7294 animals from 13 breeds in the training set and 2277 animals from seven breeds (Angus, Red Angus, Hereford, Charolais, Gelbvieh, Limousin, and Simmental) in the evaluation set. Six single-breed and four across-breed genomic predictors were trained using pooled data from purebred animals. Molecular breeding values were evaluated using field data, including genotypes for 2227 animals and phenotypic records of animals born in 2008 or later. Accuracies of molecular breeding values were estimated based on the genetic correlation between the molecular breeding value and trait phenotype. Results With one exception, the estimated genetic correlations of within-breed molecular breeding values with trait phenotype were greater than 0.28 when evaluated in the breed used for training. Most estimated genetic correlations for the across-breed trained molecular breeding values were moderate (> 0.30). When molecular breeding values were evaluated in breeds that were not in the training set, estimated genetic correlations clustered around zero. Conclusions Even for closely related breeds, within- or across-breed trained molecular breeding values have limited prediction accuracy for breeds that were not in the training set. For breeds in the training

  8. Breeding monkeys for biomedical research

    NASA Technical Reports Server (NTRS)

    Bourne, G. H.; Golarzdebourne, M. N.; Keeling, M. E.

    1973-01-01

    Captive bred rhesus monkeys show much less pathology than wild born animals. The monkeys may be bred in cages or in an outdoor compound. Cage bred animals are not psychologically normal which makes then unsuited for some types of space related research. Compound breeding provides contact between mother and infant and an opportunity for the infants to play with their peers which are important requirements to help maintain their behavioral integrity. Offspring harvested after a year in the compound appear behaviorally normal and show little histopathology. Compound breeding is also an economical method for the rapid production of young animals. The colony can double its size about every two and a half years.

  9. Temporal Patterns of Abundance of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) and Mitochondrial DNA Analysis of Ae. albopictus in the Central African Republic

    PubMed Central

    Kamgang, Basile; Ngoagouni, Carine; Manirakiza, Alexandre; Nakouné, Emmanuel; Paupy, Christophe; Kazanji, Mirdad

    2013-01-01

    The invasive Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) was first reported in central Africa in 2000, in Cameroon, with the indigenous mosquito species Ae. aegypti (Diptera: Culicidae). Today, this invasive species is present in almost all countries of the region, including the Central African Republic (CAR), where it was first recorded in 2009. As invasive species of mosquitoes can affect the distribution of native species, resulting in new patterns of vectors and concomitant risk for disease, we undertook a comparative study early and late in the wet season in the capital and the main cities of CAR to document infestation and the ecological preferences of the two species. In addition, we determined the probable geographical origin of invasive populations of Ae. albopictus with two mitochondrial DNA genes, COI and ND5. Analysis revealed that Ae. aegypti was more abundant earlier in the wet season and Ae. albopictus in the late wet season. Used tyres were the most heavily colonized productive larval habitats for both species in both seasons. The invasive species Ae. albopictus predominated over the resident species at all sites in which the two species were sympatric. Mitochondrial DNA analysis revealed broad low genetic diversity, confirming recent introduction of Ae. albopictus in CAR. Phylogeographical analysis based on COI polymorphism indicated that the Ae. albopictus haplotype in the CAR population segregated into two lineages, suggesting multiple sources of Ae. albopictus. These data may have important implications for vector control strategies in central Africa. PMID:24349596

  10. Breed base representation in dairy animals of 5 breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inheritance of DNA from different dairy breeds can be determined by genotyping, just as individual ancestors such as parents, grandparents, or even great grandparents can be identified correctly in a high percentage of the cases by genotyping even if not reported or reported incorrectly in pedigrees...

  11. Evaluation of DeltaGard® Ground Application Against Aedes albopictus in a Residential Area in St. Augustine, Florida.

    PubMed

    Drake, Lisa L; Gibson, Jennifer; Smith, Michael L; Farooq, Muhammad; Sallam, Mohamed F; Xue, Rui-De

    2016-06-01

    Aedes albopictus is an invasive species that poses a health threat in many residential neighborhoods throughout Florida. Aedes albopictus is a high priority for mosquito control efforts in the state. The efficacy of DeltaGard(®) (AI 2% deltamethrin) application against Ae. albopictus was evaluated in a residential area in St. Augustine, FL. DeltaGard was applied using a truck-mounted ultra-low-volume aerosol generator along 3 streets in a residential neighborhood. Caged mosquito mortality and droplet density data were recorded. Leaf clippings from houses on treated streets were bioassayed against laboratory-reared Ae. albopictus. Overall, the DeltaGard application was found to be more effective in the front yard of the houses, resulting in 78.3% mortality in caged mosquitoes, 42 % mortality in leaf bioassays, and 50.5 nl/cc in spray density. Based on the amount of vegetation and residential barriers around the houses, the application caused only 46.3% mortality in caged mosquitoes, 7.5% mortality in leaf bioassays, and 5.4 nl/cc in spray density in the back yard sites. PMID:27280356

  12. Breeding stage influences space use of female American avocets in San Francisco Bay, California

    USGS Publications Warehouse

    Demers, Scott A.; Colwell, M.A.; Takekawa, J.Y.; Ackerman, J.T.

    2008-01-01

    Female American Avocets (Recurvirostra americana) were radio-marked (N=15) and tracked in the South San Francisco Bay, California, to determine if space use varied by breeding stage. Visual observations were used to determine breeding stage (pre-incubation, incubation, brood-rearing, post-breeding) of marked avocets. Space use measurements (linear movements, home ranges, core areas, and average distance from nest) varied significantly among breeding stages. Space use was greatest for the post-breeding stage, followed by pre-incubation, incubation, and brood-rearing. Most avocet nests (93%) were located within their pre-incubation core area boundaries, whereas only 36% of nests were within post-breeding core areas. Distance between daily location and future nest sites decreased significantly as the number of days prior to incubation decreased, suggesting that avocets prospected future nest sites several weeks prior to nesting. These data indicate that breeding stage influences space use of female American Avocets and illustrates the importance of delineating breeding stages to better understand space use of avian species.

  13. Repellent effect of plant essential oils against Aedes albopictus.

    PubMed

    Yang, Pin; Ma, Yajun

    2005-12-01

    Six essential oils: asteraceae oil, rutaceae oil, mentha piperta oil, carvacryl oil, citronella oil, and eucalyptus oil were tested for evaluation of their repellent effects against Aedes albopictus mosquitoes under laboratory conditions. Only citronella oil and eucalyptus oil were tested with human beings. There was considerable protection for mice. Carvacryl oil (7%) provided 100% protection for mice after 7 h. Eucalyptus oil (15%) gave protection to humans for least 3 h; the protection time was prolonged to 5 h after adding 5% vanillin. The mixture could be developed into a practical product after the field evaluation. PMID:16599157

  14. Forage Breeding and New Varieties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At Agriculture and Agri-Food Canada, the focus of the forage breeding program is to identify and develop novel germplasm and cultivars. The main objective is to produce cultivars with superior persistence, nutritive value and forage yield. This program also emphasizes two other objectives, namely:...

  15. Genomic selection in plant breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomic selection (GS) is a method to predict the genetic value of selection candidates based on the genomic estimated breeding value (GEBV) predicted from high-density markers positioned throughout the genome. Unlike marker-assisted selection, the GEBV is based on all markers including both minor ...

  16. USDA lettuce breeding and genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The lettuce industry of California requires continued development of improved, adapted cultivars to meet new disease and insect problems, changes in the market, and changes in growing procedures. The USDA lettuce breeding and genetics project aims to incorporate valuable traits into crisphead, mixed...

  17. The evolution of potato breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato cultivars in most regions of the world are tetraploid and clonally propagated. For over a century, the breeding strategy has been phenotypic recurrent selection. However, the polyploid nature of the crop prevents breeders from eliminating deleterious alleles and assembling positive alleles fo...

  18. Breeding and propagating oakleaf hydrangeas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An oakleaf hydrangea breeding program at the U.S. National Arboretum’s worksite in McMinnville, Tenn. was started in 1996 for the purpose of developing attractive, compact oakleaf hydrangea cultivars suitable for use in small residential gardens. ‘Ruby Slippers’ and ‘Munchkin’ oakleaf hydrangeas we...

  19. Forage breeding and new varieties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At Agriculture and Agri-Food Canada, the focus of the forage breeding program is to identify and develop novel germplasm and cultivars. The main objective is to produce cultivars with superior persistence, nutritive value and forage yield. This program also emphasizes two other objectives, namely:...

  20. METAPOPULATION STRUCTURE AND DYNAMICS OF POND BREEDING

    EPA Science Inventory

    Our review indicates that pond breeding amphibians exhibit highly variable spatial and temporal population dynamics, such that no single generalized model can realistically describe these animals. We propose that consideration of breeding pond permanence, and adaptations to pond ...

  1. Assessment of Aedes albopictus (Skuse) (Diptera: Culicidae) clutch size in wild and laboratory populations.

    PubMed

    Davis, Timothy J; Kline, Daniel L; Kaufman, Phillip E

    2016-06-01

    Aedes albopictus (Skuse) is an invasive mosquito species found across the southern U.S. with range expansion into many northern states. Intra- and interspecific larval competition have been evaluated for Ae. albopictus with respect to subsequent adult size, immature and adult survivability, and its capacity to vector pathogens as an adult. However, limited data are available on egg production as related to larval rearing conditions. Because Ae. albopictus is a container-inhabiting mosquito that oviposits in resource-limited habitats, it is found under variable density-dependent conditions. Therefore, we examined the impact of specific rearing conditions on Ae. albopictus clutch size and adult body size; comparing the egg production values and wing lengths from known developmental densities to those from field-collected populations. Field populations varied significantly among collection sites in mean clutch size (23 to 46). These clutch sizes were comparable to the mean clutch sizes of females reared at the larval densities of nine (20 eggs) and three (53 eggs) larvae per 3 ml of water in the laboratory. Field populations experienced density-dependent effects impacting adult mosquito size. Mosquitoes from the four sample sites had mean wing lengths of 1.99, 2.47, 2.51, and 2.54 mm, which were less than the mean wing length of mosquitoes reared at larval densities of three larvae per 3 ml of water (2.57 mm). PMID:27232119

  2. TALEN-based gene disruption in the dengue vector Aedes aegypti.

    PubMed

    Aryan, Azadeh; Anderson, Michelle A E; Myles, Kevin M; Adelman, Zach N

    2013-01-01

    In addition to its role as the primary vector for dengue viruses, Aedes aegypti has a long history as a genetic model organism for other bloodfeeding mosquitoes, due to its ease of colonization, maintenance and reproductive productivity. Though its genome has been sequenced, functional characterization of many Ae. aegypti genes, pathways and behaviors has been slow. TALE nucleases (TALENs) have been used with great success in a number of organisms to generate site-specific DNA lesions. We evaluated the ability of a TALEN pair to target the Ae. aegypti kmo gene, whose protein product is essential in the production of eye pigmentation. Following injection into pre-blastoderm embryos, 20-40% of fertile survivors produced kmo alleles that failed to complement an existing kh(w) mutation. Most of these individuals produced more than 20% white-eyed progeny, with some producing up to 75%. Mutant alleles were associated with lesions of 1-7 bp specifically at the selected target site. White-eyed individuals could also be recovered following a blind intercross of G1 progeny, yielding several new white-eyed strains in the genetic background of the sequenced Liverpool strain. We conclude that TALENs are highly active in the Ae. aegypti germline, and have the potential to transform how reverse genetic experiments are performed in this important disease vector. PMID:23555893

  3. Spatial genetic structure of Aedes aegypti mosquitoes in mainland Southeast Asia.

    PubMed

    Hlaing, Thaung; Tun-Lin, Willoughby; Somboon, Pradya; Socheat, Duong; Setha, To; Min, Sein; Thaung, Sein; Anyaele, Okorie; De Silva, Babaranda; Chang, Moh Seng; Prakash, Anil; Linton, Yvonne; Walton, Catherine

    2010-07-01

    Aedes aegypti mosquitoes originated in Africa and are thought to have spread recently to Southeast Asia, where they are the major vector of dengue. Thirteen microsatellite loci were used to determine the genetic population structure of A. aegypti at a hierarchy of spatial scales encompassing 36 sites in Myanmar, Cambodia and Thailand, and two sites in Sri Lanka and Nigeria. Low, but significant, genetic structuring was found at all spatial scales (from 5 to >2000 km) and significant F IS values indicated genetic structuring even within 500 m. Spatially dependent genetic-clustering methods revealed that although spatial distance plays a role in shaping larger-scale population structure, it is not the only factor. Genetic heterogeneity in major port cities and genetic similarity of distant locations connected by major roads, suggest that human transportation routes have resulted in passive long-distance migration of A. aegypti. The restricted dispersal on a small spatial scale will make localized control efforts and sterile insect technology effective for dengue control. Conversely, preventing the establishment of insecticide resistance genes or spreading refractory genes in a genetic modification strategy would be challenging. These effects on vector control will depend on the relative strength of the opposing effects of passive dispersal. PMID:25567928

  4. Vector Competence in West African Aedes aegypti Is Flavivirus Species and Genotype Dependent

    PubMed Central

    Dickson, Laura B.; Sanchez-Vargas, Irma; Sylla, Massamba; Fleming, Karen; Black, William C.

    2014-01-01

    Background Vector competence of Aedes aegypti mosquitoes is a quantitative genetic trait that varies among geographic locations and among different flavivirus species and genotypes within species. The subspecies Ae. aegypti formosus, found mostly in sub-Saharan Africa, is considered to be refractory to both dengue (DENV) and yellow fever viruses (YFV) compared to the more globally distributed Ae. aegypti aegypti. Within Senegal, vector competence varies with collection site and DENV-2 viral isolate, but knowledge about the interaction of West African Ae. aegypti with different flaviviruses is lacking. The current study utilizes low passage isolates of dengue-2 (DENV-2-75505 sylvatic genotype) and yellow fever (YFV BA-55 -West African Genotype I, or YFV DAK 1279-West African Genotype II) from West Africa and field derived Ae. aegypti collected throughout Senegal to determine whether vector competence is flavivirus or virus genotype dependent. Methodology/Principal Findings Eight collections of 20–30 mosquitoes from different sites were fed a bloodmeal containing either DENV-2 or either isolate of YFV. Midgut and disseminated infection phenotypes were determined 14 days post infection. Collections varied significantly in the rate and intensity of midgut and disseminated infection among the three viruses. Conclusions/Significance Overall, vector competence was dependent upon both viral and vector strains. Importantly, contrary to previous studies, sylvatic collections of Ae. aegypti showed high levels of disseminated infection for local isolates of both DENV-2 and YFV. PMID:25275366

  5. Establishment of Aedes japonicus japonicus and Its Colonization of Container Habitats in Michigan

    PubMed Central

    KAUFMAN, MICHAEL G.; STANUSZEK, WILLIAM W.; BROUHARD, ELIZABETH A.; KNEPPER, RANDALL G.; WALKER, EDWARD D.

    2014-01-01

    Oviposition dynamics and colonization of container habitats by the invasive species, Aedes (Finlaya) japonicus japonicus (Theobald) were examined through the use of ovistrips placed in buckets, and larval surveys of tree holes and tires at sites in central Michigan. In general, oviposition and colonization increased during the study periods, with several sites showing large increases from <10% Ae. j. japonicus initially to over 60% in the following years. Seasonally, higher proportions of Ae. j. japonicus were found in spring and fall collection periods. Ae. j. japonicus larvae co-occurred in the artificial containers with Ae. triseriatus, Ae. hendersoni, several Culex spp., and Anopheles spp. Recent surveys of tire and tree hole habitats at our study areas in mid-Michigan revealed that Ae. j. japonicus had colonized most of these habitats, but maintained relatively low populations in tree holes occupied by Ae. triseriatus. Trends seen in tires from 2008 to 2011, and from gravid trap and New Jersey light traps in 2005–2011, suggest that Ae. j. japonicus populations are stabilizing as they integrate into native Michigan mosquito communities. PMID:23270158

  6. Genetic Diversity of US Sheep Breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the genetic relationships between US sheep breeds is useful in developing conservation strategies and actions. A broad sampling of individual sheep from 28 breeds was performed. Breed types included: fine wool, meat types, long wool, hair, prolific, and fat tailed. Blood and semen samp...

  7. Considerations related to breed or biological type.

    PubMed

    Van Eenennaam, Alison L

    2013-11-01

    This article reviews the literature on breed, biological type, and breeding system and their impact on female fertility, especially as they relate to heifer development. The attributes of different breeding systems and their appropriate use is discussed. In addition, the extant and emerging selection tools that are available for replacement heifer selection are reviewed. PMID:24182431

  8. Traditional breeding objectives and practices of goat, sheep and cattle smallholders in The Gambia and implications in relation to the design of breeding interventions.

    PubMed

    Ejlertsen, Maria; Poole, Jane; Marshall, Karen

    2013-01-01

    This paper describes the traditional breeding objectives and practices of West African Dwarf goat, Djallonke sheep, and N'dama cattle keepers in The Gambia and discusses the implications of these on the design of breeding-related interventions to improve livestock productivity. Data were collected via surveys implemented within three study sites in The Gambia, where traditional mixed crop-livestock smallholder farming predominates. The surveys comprised a participatory rural appraisal conducted in nine communities and a household questionnaire targeting 238 households. Livestock-keeping households were classified as 'poorer' or 'wealthier' based on the number of cattle owned. The most important objectives for keeping all species of livestock for the poorer groups (0 to 10 cattle) was 'savings and insurance', followed by 'income' and 'ceremonial/dowry' for the small ruminants and 'manure' and 'draught' for both cows and bulls. In contrast, for the wealthier group (more than 10 cattle), savings and insurance was the fourth to seventh ranked production objective (depending on species), with the most important production objectives being ceremonial/dowry for goats, income for sheep and manure for cows and bulls. An analysis of breeding practices indicated that breeding animals are selected on criteria which partially align to the breeding objectives, animals are rarely purchased for the purpose of breed improvement, knowledge of the cause and consequence of inbreeding is low and breeding decision makers may not necessarily be the livestock owner, particularly if the livestock owner is a women. Given this, it is suggested that capacity building on breeding-related issues, particularly in relation to the selection of breeding animals and specifically targeted at the different socioeconomic groups of livestock keepers, may be an appropriate, effective and relatively low-cost breeding intervention. PMID:22706889

  9. Larvicidal Activity of Citrus Limonoids against Aedes albopictus Larvae

    PubMed Central

    Bilal, Hazrat; Akram, Waseem; Ali-Hassan, Soaib

    2012-01-01

    Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecticides therefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to suppress mosquito larval population. Methods: WHO recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used. Results: Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis) was the best in terms of LC50 (297 ppm), % mortality (97%) and LT50 (18.49 hours) then freutrall early (Citrus reticulate) with LC50 (377.4 ppm), % mortality (88%) and LT50 (31 hours), While nomilin gave lowest LC50 (121.04 ppm) than limonin (382.22 ppm) after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 μg/ml and 21.19 μg/ml) than freutrall early (5.29 μg/ml and 3.89 μg/ml) respectively. Conclusion: Valencia late showed best results in term of LC50, LT50 and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required. PMID:23378967

  10. Molecular Analysis of the Aedes aegypti Carboxypeptidase Gene Family

    PubMed Central

    Isoe, Jun; Zamora, Jorge; Miesfeld, Roger L.

    2009-01-01

    To gain a better understanding of coordinate regulation of protease gene expression in the mosquito midgut, we undertook a comprehensive molecular study of digestive carboxypeptidases in Aedes aegypti. Through a combination of cDNA cloning using degenerate PCR primers, and database mining of the recently completed Ae. aegypti genome, we cloned and characterized 18 Ae. aegypti carboxypeptidase genes. Bioinformatic analysis revealed that 11 of these genes belong to the carboxypeptidase A family (AaCPA-I through AaCPA-XI), and seven to the carboxypeptidase B gene family (AaCPB-I through AaCPB-VII). Phylogenetic analysis of 32 mosquito carboxypeptidases from five different species indicated that most of the sequence divergence in the carboxypeptidase gene family occurred prior to the separation of Aedes and Anopheles mosquito lineages. Unlike the CPA genes that are scattered throughout the Ae. aegypti genome, six of seven CPB genes were found to be located within a single 120 kb genome contig, suggesting that they most likely arose from multiple gene duplication events. Quantitative expression analysis revealed that 11 of the Ae. aegypti carboxypeptidase genes were induced up to 40-fold in the midgut in response to blood meal feeding, with peak expression times ranging from 3-36 hours post-feeding depending on the gene. PMID:18977440

  11. Assortative mating and fragmentation within dog breeds

    PubMed Central

    2008-01-01

    Background There are around 400 internationally recognized dog breeds in the world today, with a remarkable diversity in size, shape, color and behavior. Breeds are considered to be uniform groups with similar physical characteristics, shaped by selection rooted in human preferences. This has led to a large genetic difference between breeds and a large extent of linkage disequilibrium within breeds. These characteristics are important for association mapping of candidate genes for diseases and therefore make dogs ideal models for gene mapping of human disorders. However, genetic uniformity within breeds may not always be the case. We studied patterns of genetic diversity within 164 poodles and compared it to 133 dogs from eight other breeds. Results Our analyses revealed strong population structure within poodles, with differences among some poodle groups as pronounced as those among other well-recognized breeds. Pedigree analysis going three generations back in time confirmed that subgroups within poodles result from assortative mating imposed by breed standards as well as breeder preferences. Matings have not taken place at random or within traditionally identified size classes in poodles. Instead, a novel set of five poodle groups was identified, defined by combinations of size and color, which is not officially recognized by the kennel clubs. Patterns of genetic diversity in other breeds suggest that assortative mating leading to fragmentation may be a common feature within many dog breeds. Conclusion The genetic structure observed in poodles is the result of local mating patterns, implying that breed fragmentation may be different in different countries. Such pronounced structuring within dog breeds can increase the power of association mapping studies, but also represents a serious problem if ignored. In dog breeding, individuals are selected on the basis of morphology, behaviour, working or show purposes, as well as geographic population structure. The same

  12. Induction of microsomal cytochrome P450s by tire-leachate compounds, habitat components of Aedes albopictus mosquito larvae.

    PubMed

    Suwanchaichinda, Chansak; Brattsten, Lena B

    2002-02-01

    Benzothiazole (BZT) and its derivatives are the major leachate compounds of automobile tires, the principal breeding habitat of Aedes albopictus, particularly in the United States. Effects of the compounds on insecticide toxicity, and activities and expression of microsomal cytochrome P450s (P450s) in the mosquito larvae were examined. Mosquito larvae were more tolerant to carbaryl, rotenone, and temephos when they were pre-exposed to tire-leachate compounds, particularly BZT. There was no change in toxicity from the aldrin treatment by BZT. The effect of BZT was reversed when a P450 inhibitor, piperonyl butoxide, was applied in admixture with the insecticides. Microsomes from BZT-treated larvae had increased peroxidation activity of tetramethylbenzidine. This correlated with increased intensity of SDS-PAGE protein bands corresponding to molecular weights of 59 and 62 kD, which were detected as heme-containing proteins, a characteristic of P450s. The results suggest that BZT induces P450s, which detoxify insecticides and thus cause insecticide tolerance in the mosquito larvae. Arch. PMID:11816022

  13. A new ovitrap made of slow release natural materials containing pyriproxyfen for Aedes aegypti (Diptera:Culicidae) control.

    PubMed

    Juan, Laura; Seccacini, Emilia; Zerba, Eduardo; Licastro, Susana

    2013-07-01

    ABSTRACT This initial study is aimed to measure the performance of incorporating pyriproxyfen in natural materials with low environmental impact to obtain slow release formulations that can be used as larvicidal or autocidal ovitraps avoiding hatched Aedes aegypti (L.) eggs to emerge as adults. Hollow candles made of beeswax or paraffin:stearin 1:1 mixture containing pyriproxyfen 0.01 and 0.05% were prepared and used as holding water containers for larval bioassay. Pyriproxyfen was released quickly into the larvae-breeding water. Ae. aegypti larvae were introduced immediately after the addition of tap water to the hollow candles (t = 1 min) or after 1, 4, and 8 h. More than 40% of the larvae did not emerge as adults for t = 1 min, reaching 80-100% when the larvae were added after 1 or 4 h, respectively. The hollow candles were kept at room temperature, and water was replaced every 15 d. Bioassays performed every 30 d showed that the residual activity obtained for both matrices and both concentrations of pyriproxyfen was higher than 360 d, with 100% inhibition of adult emergence. PMID:23926792

  14. Hatching response of Aedes aegypti (Diptera: Culicidae) eggs at low temperatures: effects of hatching media and storage conditions.

    PubMed

    Byttebier, B; De Majo, M S; De Majo, M S; Fischer, S

    2014-01-01

    In temperate regions, Aedes aegypti (L.) (Diptera: Culicidae) populations remain in the egg stage during the cold season. To ensure the start of a new breeding season, eggs should hatch at the beginning of a favorable period. The aim of the current study was to investigate the hatching response of two Ae. aegypti egg batches collected and stored for 3 mo under different conditions, to different low immersion temperatures. Two different hatching media (water and yeast solution) were used for the first batch and only one (water) for the second egg batch. Eggs were immersed for 8 d, during which the number of hatched eggs was recorded daily. The proportion of hatched eggs, delay of the hatching response, proportion of dead larvae, and proportion of remaining eggs within the first egg batch were compared between the two hatching media at each temperature. These parameters also were compared between the two batches immersed in water. Hatching rates were higher and faster in the yeast solution. The hatching response was lower at lower immersion temperatures and among eggs stored under field conditions at colder temperatures (second batch). Among the eggs stored in the laboratory (first batch), older eggs exhibited lower hatching response. The proportion of dead larvae was higher in the yeast solution and in the eggs stored in the laboratory. The conditions that triggered a lower hatching response led to higher proportions of remaining eggs, allowing the population to maintain an egg bank for future favorable opportunities. PMID:24605458

  15. Worldwide patterns of genetic differentiation imply multiple 'domestications' of Aedes aegypti, a major vector of human diseases.

    PubMed

    Brown, Julia E; McBride, Carolyn S; Johnson, Petrina; Ritchie, Scott; Paupy, Christophe; Bossin, Hervé; Lutomiah, Joel; Fernandez-Salas, Ildefonso; Ponlawat, Alongkot; Cornel, Anthony J; Black, William C; Gorrochotegui-Escalante, Norma; Urdaneta-Marquez, Ludmel; Sylla, Massamba; Slotman, Michel; Murray, Kristy O; Walker, Christopher; Powell, Jeffrey R

    2011-08-22

    Understanding the processes by which species colonize and adapt to human habitats is particularly important in the case of disease-vectoring arthropods. The mosquito species Aedes aegypti, a major vector of dengue and yellow fever viruses, probably originated as a wild, zoophilic species in sub-Saharan Africa, where some populations still breed in tree holes in forested habitats. Many populations of the species, however, have evolved to thrive in human habitats and to bite humans. This includes some populations within Africa as well as almost all those outside Africa. It is not clear whether all domestic populations are genetically related and represent a single 'domestication' event, or whether association with human habitats has developed multiple times independently within the species. To test the hypotheses above, we screened 24 worldwide population samples of Ae. aegypti at 12 polymorphic microsatellite loci. We identified two distinct genetic clusters: one included all domestic populations outside of Africa and the other included both domestic and forest populations within Africa. This suggests that human association in Africa occurred independently from that in domestic populations across the rest of the world. Additionally, measures of genetic diversity support Ae. aegypti in Africa as the ancestral form of the species. Individuals from domestic populations outside Africa can reliably be assigned back to their population of origin, which will help determine the origins of new introductions of Ae. aegypti. PMID:21227970

  16. Rapid estimation of Aedes aegypti population size using simulation modeling, with a novel approach to calibration and field validation.

    PubMed

    Williams, Craig R; Johnson, Petrina H; Long, Sharron A; Rapley, Luke P; Ritchie, Scott A

    2008-11-01

    New approaches for control of the dengue vector Aedes aegypti (L.) are being developed, including the potential introduction of life-shortening symbiont bacteria into field populations and the release of transgenic strains with reduced vector competency. With these new approaches comes the need for rapid estimations of existing field population size. Here, we describe the use of simulation modeling with container-inhabiting mosquito simulation (CIMSiM) for estimation of Ae. aegypti pupal crop size in north Queensland, Australia. CIMSiM was calibrated for local conditions by deploying "sentinel key containers" (tire, 2-liter plastic bucket, 0.6-liter pot plant base, and tarpaulin indentation) in which water flux and pupal productivity were studied for 72 d. Iterative adjustment of CIMSiM parameters was used to fit model outputs to match that of sentinel key containers. This calibrated model was then used in a blind field validation, in which breeding container and local meteorological data were used to populate CIMSiM, and model outputs were compared with a field pupal survey. Actual pupae per ha during two 10-d periods in 2007 fell within 95% confidence intervals of simulated pupal crop estimates made by 10 replicate simulations in CIMSiM, thus providing a successful field validation. Although the stochasticity of the field environment can never be wholly simulated, CIMSiM can provide field-validated estimates of pupal crop in a timely manner by using simple container surveys. PMID:19058645

  17. Population-Wide Failure to Breed in the Clark’s Nutcracker (Nucifraga columbiana)

    PubMed Central

    Schaming, Taza D.

    2015-01-01

    In highly variable environments, conditions can be so stressful in some years that entire populations forgo reproduction in favor of higher likelihood of surviving to breed in future years. In two out of five years, Clark’s nutcrackers (Nucifraga Columbiana) in the Greater Yellowstone Ecosystem exhibited population-wide failure to breed. Clark’s nutcrackers at the study site experienced substantial interannual differences in food availability and weather conditions, and the two nonbreeding years corresponded with low whitebark pine (Pinus albicaulis) cone crops the previous autumn (≤ an average of 8 ± 2 cones per tree versus ≥ an average of 20 ± 2 cones per tree during breeding years) and high snowpack in early spring (≥ 61.2 ± 5.5 cm versus ≤ 51.9 ± 4.4 cm during breeding years). The average adult body condition index during the breeding season was significantly lower in 2011 (-1.5 ± 1.1), a nonbreeding year, as compared to 2012 (6.2 ± 2.0), a breeding year. The environmental cues available to the birds prior to breeding, specifically availability of cached whitebark pine seeds, may have allowed them to predict that breeding conditions would be poor, leading to the decision to skip breeding. Alternatively, the Clark’s nutcrackers may have had such low body energy stores that they chose not to or were unable to breed. Breeding plasticity would allow Clark’s nutcrackers to exploit an unpredictable environment. However, if large-scale mortality of whitebark pines is leading to an increase in the number of nonbreeding years, there could be serious population-level and ecosystem-wide consequences. PMID:25970294

  18. Cancer risks in Swedish Lapps who breed reindeer

    SciTech Connect

    Wiklund, K.; Holm, L.E.; Eklund, G. )

    1990-12-01

    Cancer risks during the period 1961-1984 were studied in a cohort of 2,034 Swedish reindeer-breeding Lapps, a unique group whose culture and life-style differ considerably from those in the rest of the Swedish population. A total of 100 cases of cancer were observed versus 163 expected. Statistically significantly decreased risks were found for cancers of the colon, respiratory organs, female breast, male genital organs, and kidneys, and for malignant lymphomas. The stomach was the only site with a significantly increased risk. Reindeer-breeding Lapps have ingested fallout products via the lichen-reindeer-man food chain since the 1950s. However, no increased risk was found for the cancer sites considered to be most sensitive to radiation.

  19. Mosquitocidal and Oviposition Repellent Activities of the Extracts of Seaweed Bryopsis pennata on Aedes aegypti and Aedes albopictus.

    PubMed

    Yu, Ke-Xin; Wong, Ching-Lee; Ahmad, Rohani; Jantan, Ibrahim

    2015-01-01

    The ever-increasing threat from infectious diseases and the development of insecticide resistance in mosquito populations drive the global search for new natural insecticides. The aims of this study were to evaluate the mosquitocidal activity of the extracts of seaweed Bryopsis pennata against dengue vectors Aedes aegypti and Aedes albopictus, and determine the seaweed's toxic effect on brine shrimp nauplii (as a non-target organism). In addition, the chemical compositions of the active larvicidal extract and fraction were analyzed by using liquid chromatography-mass spectrometry (LC-MS). Chloroform extract exhibited strong ovicidal activity (with LC50 values of 229.3 and 250.5 µg/mL) and larvicidal activity against Ae. aegypti and Ae. albopictus. The larvicidal potential of chloroform extract was further ascertained when its A7 fraction exhibited strong toxic effect against Ae. aegypti (LC50 = 4.7 µg/mL) and Ae. albopictus (LC50 = 5.3 µg/mL). LC-MS analysis of the chloroform extract gave a tentative identification of 13 compounds; Bis-(3-oxoundecyl) tetrasulfide was identified as the major compound in A7 fraction. Methanol extract showed strong repellent effect against female oviposition, along with weak adulticidal activity against mosquito and weak toxicity against brine shrimp nauplii. The mosquitocidal results of B. pennata suggest further investigation for the development of effective insecticide. PMID:26247928

  20. Effect of housing factors on infestation by Aedes aegypti (L.) and Aedes albopictus Skuse in urban Hanoi City, Vietnam.

    PubMed

    Tsuzuki, Ataru; Sunahara, Toshihiko; Duoc, Vu Trong; Le Nguyen, Hoang; Higa, Yukiko; Phong, Tran Vu; Minakawa, Noboru

    2013-11-01

    To determine the effect of housing factors on infestation with Aedes aegypti (L.) and Aedes albopictus Skuse we conducted an entomological survey and inspection of 267 urban houses in Hanoi City, Vietnam. Two hundred ten pupae and 194 adult Ae. aegypti were collected from 19 and 88 houses, respectively. One hundred eighty-one pupae and 24 adult Ae. albopictus were collected from 21 and 14 houses, respectively. The presence of a private well was associated with increasing infestation with Ae. aegypti adults (p = 0.01) and increased the risk of Ae. aegypti and Ae. albopictus pupal presence (p = 0.04 for Ae. aegypti, p = 0.03 for Ae. albopictus). The presence of an outdoor space in the household premises was associated with a higher risk of Ae. albopictus pupal presence (p = 0.004) and a higher risk of high levels of Ae. albopictus adults (p = 0.01); however, it had no association with infestation with Ae. aegypti. The presence of an air-conditioning unit (p = 0.03) and four or more rooms in the residence (p = 0.02) were negatively and positively associated with the risk for Ae. albopictus presence, respectively. PMID:24450235

  1. The Effects of Interspecific Courtship on the Mating Success of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Males

    PubMed Central

    Bargielowski, Irka; Blosser, Erik; Lounibos, L. P.

    2015-01-01

    Satyrization, a form of asymmetric reproductive interference, has recently been shown to play a role in competitive displacements of Aedes aegypti (L.) by Aedes albopictus (Skuse). Furthermore, female Ae. aegypti from populations in sympatry with Ae. albopictus have evolved reproductive character displacement and changes in mating behavior to reduce interspecific mating. In this article, we examine evolutionary responses of males to interspecific mating and show that satyrization has also evoked reproductive character displacement in males. We demonstrate that the presence of heterospecific females negatively influences conspecific mating success in male Ae. aegypti, most likely due to misdirected courting or mating efforts, and that males of this species from populations in sympatry with Ae. albopictus have evolved to be less influenced by the presence of heterospecific females than their allopatric counterparts. Conversely, we suggest that the presence of conspecifics may, in some circumstances, increase interspecific mating. This study demonstrates that co-occurrences of these two invasive species may lead to evolution and adaptation of reproductive behaviors to changing circumstances. Understanding the processes driving development of mate choice preferences or avoidance mechanisms may help predict future changes in the distribution and abundance of insect vectors or pests.

  2. Behavioral responses of Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Anopheles minimus against various synthetic and natural repellent compounds.

    PubMed

    Sathantriphop, Sunaiyana; White, Sabrina A; Achee, Nicole L; Sanguanpong, Unchalee; Chareonviriyaphap, Theeraphap

    2014-12-01

    The behavioral responses of colony populations of Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Anopheles minimus to four essential oils (citronella, hairy basil, catnip, and vetiver), two standard repellents (DEET and picaridin), and two synthetic pyrethroids (deltamethrin and permethrin) were conducted in the laboratory using an excito-repellency test system. Results revealed that Cx. quinquefasciatus and An. minimus exhibited much stronger behavioral responses to all test compounds (65-98% escape for contact, 21.4-94.4% escape for non-contact) compared to Ae. aegypti (3.7-72.2% escape (contact), 0-31.7% (non-contact)) and Ae. albopictus (3.5-94.4% escape (contact), 11.2-63.7% (non-contact)). In brief, essential oil from vetiver elicited the greatest irritant responses in Cx. quinquefasciatus (96.6%) and An. minimus (96.5%) compared to the other compounds tested. The synthetic pyrethroids caused a stronger contact irritant response (65-97.8% escape) than non-contact repellents (0-50.8% escape for non-contact) across all four mosquito species. Picaridin had the least effect on all mosquito species. Findings from the current study continue to support the screening of essential oils from various plant sources for protective properties against field mosquitoes. PMID:25424262

  3. Age-Stage, Two-Sex Life Table Characteristics of Aedes albopictus and Aedes Aegypti in Penang Island, Malaysia.

    PubMed

    Maimusa, Hamisu A; Ahmad, Abu Hassan; Kassim, Nur Faeza A; Rahim, Junaid

    2016-03-01

    The life table developmental attributes of laboratory colonies of wild strains of Aedes albopictus and Aedes aegypti were analyzed and compared based on the age-stage, two-sex life table. Findings inclusive in this study are: adult preoviposition periods, total preoviposition period, mean intrinsic rate of increase (r), mean finite rate of increase (λ), net reproductive rates (R0), and mean generation time (T). The total preadult development time was 9.47 days for Ae. albopictus and 8.76 days for Ae. aegypti. The life expectancy was 19.01 days for Ae. albopictus and 19.94 days for Ae. aegypti. Mortality occurred mostly during the adult stage. The mean development time for each stage insignificantly correlated with temperature for Ae. albopictus (r  =  -0.208, P > 0.05) and (r  =  -0.312, P > 0.05) for Ae. aegypti. The population parameters suggest that Ae. albopictus and Ae. aegypti populations are r-strategists characterized by a high r, a large R0, and short T. This present study provides the first report to compare the life parameters of Ae. albopictus and Ae. aegypti strains from Penang island, Malaysia. PMID:27105211

  4. Co-occurrence Patterns of the Dengue Vector Aedes aegypti and Aedes mediovitattus, a Dengue Competent Mosquito in Puerto Rico

    PubMed Central

    Little, Eliza; Barrera, Roberto; Seto, Karen C.; Diuk-Wasser, Maria

    2015-01-01

    Aedes aegypti is implicated in dengue transmission in tropical and subtropical urban areas around the world. Ae. aegypti populations are controlled through integrative vector management. However, the efficacy of vector control may be undermined by the presence of alternative, competent species. In Puerto Rico, a native mosquito, Ae. mediovittatus, is a competent dengue vector in laboratory settings and spatially overlaps with Ae. aegypti. It has been proposed that Ae. mediovittatus may act as a dengue reservoir during inter-epidemic periods, perpetuating endemic dengue transmission in rural Puerto Rico. Dengue transmission dynamics may therefore be influenced by the spatial overlap of Ae. mediovittatus, Ae. aegypti, dengue viruses, and humans. We take a landscape epidemiology approach to examine the association between landscape composition and configuration and the distribution of each of these Aedes species and their co-occurrence. We used remotely sensed imagery from a newly launched satellite to map landscape features at very high spatial resolution. We found that the distribution of Ae. aegypti is positively predicted by urban density and by the number of tree patches, Ae. mediovittatus is positively predicted by the number of tree patches, but negatively predicted by large contiguous urban areas, and both species are predicted by urban density and the number of tree patches. This analysis provides evidence that landscape composition and configuration is a surrogate for mosquito community composition, and suggests that mapping landscape structure can be used to inform vector control efforts as well as to inform urban planning. PMID:21989642

  5. Experience- and age-mediated oviposition behaviour in the yellow fever mosquito Stegomyia aegypti (=Aedes aegypti).

    PubMed

    Ruktanonchai, N W; Lounibos, L P; Smith, D L; Allan, S A

    2015-09-01

    In repeated behaviours such as those of feeding and reproduction, past experiences can inform future behaviour. By altering their behaviour in response to environmental stimuli, insects in highly variable landscapes can tailor their behaviour to their particular environment. In particular, female mosquitoes may benefit from plasticity in their choice of egg-laying site as these sites are often temporally variable and clustered. The opportunity to adapt egg-laying behaviour to past experience also exists for mosquito populations as females typically lay eggs multiple times throughout their lives. Whether experience and age affect egg-laying (or oviposition) behaviour in the mosquito Stegomyia aegypti (=Aedes aegypti) (Diptera: Culicidae) was assessed using a wind tunnel. Initially, gravid mosquitoes were provided with a cup containing either repellent or well water. After ovipositing in these cups, the mosquitoes were blood-fed and introduced into a wind tunnel. In this wind tunnel, an oviposition cup containing repellent was placed in the immediate vicinity of the gravid mosquitoes. A cup containing well water was placed at the opposite end of the tunnel so that if the females flew across the chamber, they encountered the well water cup, in which they readily laid eggs. Mosquitoes previously exposed to repellent cups became significantly more likely to later lay eggs in repellent cups, suggesting that previous experience with suboptimal oviposition sites informs mosquitoes of the characteristics of nearby oviposition sites. These results provide further evidence that mosquitoes modify behaviour in response to environmental information and are demonstrated in a vector species in which behavioural plasticity may be ecologically and epidemiologically meaningful. PMID:25982411

  6. Do Arctic breeding geese track or overtake a green wave during spring migration?

    NASA Astrophysics Data System (ADS)

    Si, Yali; Xin, Qinchuan; de Boer, Willem F.; Gong, Peng; Ydenberg, Ronald C.; Prins, Herbert H. T.

    2015-03-01

    Geese breeding in the Arctic have to do so in a short time-window while having sufficient body reserves. Hence, arrival time and body condition upon arrival largely influence breeding success. The green wave hypothesis posits that geese track a successively delayed spring flush of plant development on the way to their breeding sites. The green wave has been interpreted as representing either the onset of spring or the peak in nutrient biomass. However, geese tend to adopt a partial capital breeding strategy and might overtake the green wave to accomplish a timely arrival on the breeding site. To test the green wave hypothesis, we link the satellite-derived onset of spring and peak in nutrient biomass with the stopover schedule of individual Barnacle Geese. We find that geese track neither the onset of spring nor the peak in nutrient biomass. Rather, they arrive at the southernmost stopover site around the peak in nutrient biomass, and gradually overtake the green wave to match their arrival at the breeding site with the local onset of spring, thereby ensuring gosling benefit from the peak in nutrient biomass. Our approach for estimating plant development stages is critical in testing the migration strategies of migratory herbivores.

  7. Do Arctic breeding geese track or overtake a green wave during spring migration?

    PubMed Central

    Si, Yali; Xin, Qinchuan; de Boer, Willem F.; Gong, Peng; Ydenberg, Ronald C.; Prins, Herbert H. T.

    2015-01-01

    Geese breeding in the Arctic have to do so in a short time-window while having sufficient body reserves. Hence, arrival time and body condition upon arrival largely influence breeding success. The green wave hypothesis posits that geese track a successively delayed spring flush of plant development on the way to their breeding sites. The green wave has been interpreted as representing either the onset of spring or the peak in nutrient biomass. However, geese tend to adopt a partial capital breeding strategy and might overtake the green wave to accomplish a timely arrival on the breeding site. To test the green wave hypothesis, we link the satellite-derived onset of spring and peak in nutrient biomass with the stopover schedule of individual Barnacle Geese. We find that geese track neither the onset of spring nor the peak in nutrient biomass. Rather, they arrive at the southernmost stopover site around the peak in nutrient biomass, and gradually overtake the green wave to match their arrival at the breeding site with the local onset of spring, thereby ensuring gosling benefit from the peak in nutrient biomass. Our approach for estimating plant development stages is critical in testing the migration strategies of migratory herbivores. PMID:25735996

  8. Migratory double breeding in Neotropical migrant birds

    PubMed Central

    Rohwer, Sievert; Hobson, Keith A.; Rohwer, Vanya G.

    2009-01-01

    Neotropical migratory songbirds typically breed in temperate regions and then travel long distances to spend the majority of the annual cycle in tropical wintering areas. Using stable-isotope methodology, we provide quantitative evidence of dual breeding ranges for 5 species of Neotropical migrants. Each is well known to have a Neotropical winter range and a breeding range in the United States and Canada. However, after their first bout of breeding in the north, many individuals migrate hundreds to thousands of kilometers south in midsummer to breed a second time during the same summer in coastal west Mexico or Baja California Sur. They then migrate further south to their final wintering areas in the Neotropics. Our discovery of dual breeding ranges in Neotropical migrants reveals a hitherto unrealized flexibility in life-history strategies for these species and underscores that demographic models and conservation plans must consider dual breeding for these migrants. PMID:19858484

  9. Unconventional methods in plant breeding.

    PubMed

    Melchers, G

    There are three wass whereby unconventional methods of plant genetics can be used for applied plant breeding. 1. The time necessary for breeding by recombination can be shortened, making use of the discovery that plants can be obtained directly from the products of meiosis, the "Gonen." Two new cultivars bred in tobacco by this method already exist. 2. Microbiological methods may be applied to mutation and selection in haploid or dihaploid cell cultures. New cultivars bred by this method have not yet been published, but it should be possible to make use of this technique in plant breeding. 3. Somatic hybridization of plants by fusions of protoplasts or by uptake of nuclei and other organelles (plastids, mitochondria) or pure nucleic acids is another useful method. There exist up to now somatic hybrid plants (a) between mutants of the liverwort Sphaerocarpos donnellii, (b) some varieties of tobacco, and (c) two species of Nicotiana. All these hybrids can also be produced by conventional sexual hybridization. It is impossible to predict how often incompatibility for cross-fertilization can be surmounted by somatic hybridization, as incompatibility between two genomes must be restricted to the fertilization process, but it can work on any stage of the development of the hybrid. PMID:1032113

  10. Zika virus in Brazil and the danger of infestation by Aedes (Stegomyia) mosquitoes.

    PubMed

    Marcondes, Carlos Brisola; Ximenes, Maria de Fátima Freire de Melo

    2016-02-01

    Zika virus, already widely distributed in Africa and Asia, was recently reported in two Northeastern Brazilian: State of Bahia and State of Rio Grande do Norte, and one Southeastern: State of São Paulo. This finding adds a potentially noxious virus to a list of several other viruses that are widely transmitted by Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus in Brazil. The pathology and epidemiology, including the distribution and vectors associated with Zika virus, are reviewed. This review is focused on viruses transmitted by Aedes (Stegomyia) mosquitoes, including dengue, Chikungunya, Zika, Mayaro, and yellow fever virus, to emphasize the risks of occurrence for these arboviruses in Brazil and neighboring countries. Other species of Aedes (Stegomyia) are discussed, emphasizing their involvement in arbovirus transmission and the possibility of adaptation to environments modified by human activities and introduction in Brazil. PMID:26689277

  11. Geographical distribution of the Aedes Triseriatus Group (Diptera: Culicidae) in Mexico.

    PubMed

    Sánchez-Trinidad, Adelfo; Ordoñez-Sánchez, Félix; Valdes-Perezgasga, Ma Teresa; Sánchez-Ramos, Francisco J; Zavortink, Thomas J; Cortés-Guzmán, Antonio J; Ortega-Morales, Aldo I

    2014-06-01

    Aedes brelandi Zavortink is reported for the first time outside of the United States, where it has been found in northern and central parts of Mexico. Ae. triseriatus (Say) is reported in northern and central Mexico and Ae. zoosophus Dyar and Knab is recorded in southern Mexico. Collection records for these species in northern, central, and southern Mexico showing the current distribution of the Aedes Triseriatus Group are included. PMID:24820565

  12. Selective oviposition by Aedes aegypti (Diptera: culicidae) in response to Mesocyclops longisetus (Copepoda: Cyclopoidea) under laboratory and field conditions.

    PubMed

    Torres-Estrada, J L; Rodríguez, M H; Cruz-López, L; Arredondo-Jimenez, J I

    2001-03-01

    The influence of predacious Mesocyclops longisetus Thiebaud on the selection of oviposition sites by prey Aedes aegypti (L.) was studied under laboratory and field conditions. In both cases, gravid Ae. aegypti females were significantly more attracted to ovitraps containing copepods or to ovitraps with water in which copepods were held previously than to distilled water. Monoterpene and sesquiterpene compounds including 3-carene, alpha-terpinene, alpha-copaene, alpha-longipinene, alpha-cedrene, and delta-cadinene were found in hexane extracts of copepods by gas chromatography and mass spectrometry analyses. These compounds may be responsible for attracting gravid Ae. aegypti females and may increase the number of potential prey for the copepod. PMID:11296821

  13. First molecular genotyping of A302S mutation in the gamma aminobutyric acid (GABA) receptor in Aedes albopictus from Malaysia.

    PubMed

    Low, V L; Vinnie-Siow, W Y; Lim Y, A L; Tan, T K; Leong, C S; Chen, C D; Azidah, A A; Sofian-Azirun, M

    2015-09-01

    Given the lack of molecular evidence in altered target-site insecticide resistance mechanism in Aedes albopictus (Skuse) worldwide, the present study aims to detect the presence of A302S mutation in the gene encoding the gamma aminobutyric acid receptor resistant to dieldrin (Rdl) in Ae. albopictus for the first time from its native range of South East Asia, namely Malaysia. World Health Organization (WHO) adult susceptibility bioassay indicated a relatively low level of dieldrin resistance (two-fold) in Ae. albopictus from Petaling Jaya, Selangor. However, PCR-RFLP and direct sequencing methods revealed the presence of the A302S mutation with the predomination of heterozygous genotype (40 out of 82 individuals), followed by the resistant genotype with 11 individuals. This study represents the first field evolved instance of A302S mutation in Malaysian insect species. PMID:26695218

  14. An Unmanned Aerial Vehicle-Mounted Cold Mist Spray of Permethrin and Tetramethylfluthrin Targeting Aedes albopictus in China.

    PubMed

    Li, Chun-Xiao; Zhang, Ying-Mei; Dong, Yan-De; Zhou, Ming-Hao; Zhang, Heng-Duan; Chen, Hong-Na; Tian, Ye; Yang, Wei-Fang; Wu, Xiao-Qun; Chu, Hong-Liang; Zhao, Tong-Yan

    2016-03-01

    Aedes albopictus is the primary vector of dengue fever and dengue hemorrhagic fever in China. Although there are previous studies on the application of adulticides to control this species, the application methods have either been back-pack or vehicle-mounted systems. However, many sites are too large to be effectively treated with back-pack sprayers, and the lack of roads restricts the use of vehicle-mounted sprayers. This paper provides the first study of using unmanned aerial vehicles to conduct cold mist sprays on Ae. albopictus habitats. A spray containing 4% permethrin and 1% tetramethylfluthrin was applied at an effective application rate of 9.0 mg/m(2). This method reduced Ae. albopictus populations by more than 90%. The results indicate this novel spray system is a powerful method to achieve a rapid decline of mosquito population in Ae. albopictus habitats in China. PMID:27105218

  15. Ectoparasitism shortens the breeding season in a colonial bird.

    PubMed

    Brown, Charles R; Brown, Mary Bomberger

    2015-02-01

    When blood-feeding parasites increase seasonally, their deleterious effects may prevent some host species, especially those living in large groups where parasites are numerous, from reproducing later in the summer. Yet the role of parasites in regulating the length of a host's breeding season-and thus the host's opportunity for multiple brooding-has not been systematically investigated. The highly colonial cliff swallow (Petrochelidon pyrrhonota), a temperate-latitude migratory songbird in the western Great Plains, USA, typically has a relatively short (eight to nine week) breeding season, with birds rarely nesting late in the summer. Colonies at which ectoparasitic swallow bugs (Oeciacus vicarius) were experimentally removed by fumigation were over 45 times more likely to have birds undertake a second round of nesting than were colonies exposed to parasites. Late nesting approximately doubled the length of the breeding season, with some birds raising two broods. Over a 27 year period the percentage of birds engaging in late nesting each year increased at a colony site where parasites were removed annually. This trend could not be explained by changes in group size, climate or nesting phenology during the study. The results suggest that ectoparasitism shortens the cliff swallow's breeding season and probably prevents many individuals from multiple brooding. When this constraint is removed, selection may rapidly favour late nesting. PMID:26064606

  16. Schools as Potential Risk Sites for Vector-Borne Disease Transmission: Mosquito Vectors in Rural Schools in Two Municipalities in Colombia.

    PubMed

    Olano, Víctor Alberto; Matiz, María Inés; Lenhart, Audrey; Cabezas, Laura; Vargas, Sandra Lucía; Jaramillo, Juan Felipe; Sarmiento, Diana; Alexander, Neal; Stenström, Thor Axel; Overgaard, Hans J

    2015-09-01

    Dengue and other vector-borne diseases are of great public health importance in Colombia. Vector surveillance and control activities are often focused at the household level. Little is known about the importance of nonhousehold sites, including schools, in maintaining vector-borne disease transmission. The objectives of this paper were to determine the mosquito species composition in rural schools in 2 municipalities in Colombia and to assess the potential risk of vector-borne disease transmission in school settings. Entomological surveys were carried out in rural schools during the dry and rainy seasons of 2011. A total of 12 mosquito species were found: Aedes aegypti, Anopheles pseudopunctipennis, Culex coronator, Cx. quinquefasciatus, and Limatus durhamii in both immature and adult forms; Ae. fluviatilis, Cx. nigripalpus, Cx. corniger, and Psorophora ferox in immature forms only; and Ae. angustivittatus, Haemagogus equinus, and Trichoprosopon lampropus in adult forms only. The most common mosquito species was Cx. quinquefasciatus. Classrooms contained the greatest abundance of adult female Ae. aegypti and Cx. quinquefasciatus. The most common Ae. aegypti breeding sites were containers classified as "others" (e.g., cans), followed by containers used for water storage. A high level of Ae. aegypti infestation was found during the wet season. Our results suggest that rural schools are potentially important foci for the transmission of dengue and other mosquito-borne diseases. We propose that public health programs should be implemented in rural schools to prevent vector-borne diseases. PMID:26375902

  17. An Experimental Field Study of Delayed Density Dependence in Natural Populations of Aedes albopictus

    PubMed Central

    Walsh, Rachael K.; Bradley, Caitlin; Apperson, Charles S.; Gould, Fred

    2012-01-01

    Aedes albopictus, a species known to transmit dengue and chikungunya viruses, is primarily a container-inhabiting mosquito. The potential for pathogen transmission by Ae. albopictus has increased our need to understand its ecology and population dynamics. Two parameters that we know little about are the impact of direct density-dependence and delayed density-dependence in the larval stage. The present study uses a manipulative experimental design, under field conditions, to understand the impact of delayed density dependence in a natural population of Ae. albopictus in Raleigh, North Carolina. Twenty liter buckets, divided in half prior to experimentation, placed in the field accumulated rainwater and detritus, providing oviposition and larval production sites for natural populations of Ae. albopictus. Two treatments, a larvae present and larvae absent treatment, were produced in each bucket. After five weeks all larvae were removed from both treatments and the buckets were covered with fine mesh cloth. Equal numbers of first instars were added to both treatments in every bucket. Pupae were collected daily and adults were frozen as they emerged. We found a significant impact of delayed density-dependence on larval survival, development time and adult body size in containers with high larval densities. Our results indicate that delayed density-dependence will have negative impacts on the mosquito population when larval densities are high enough to deplete accessible nutrients faster than the rate of natural food accumulation. PMID:22563428

  18. Blood-Feeding Induces Reversible Functional Changes in Flight Muscle Mitochondria of Aedes aegypti Mosquito

    PubMed Central

    Gonçalves, Renata L. S.; Machado, Ana Carolina L.; Paiva-Silva, Gabriela O.; Sorgine, Marcos H. F.; Momoli, Marisa M.; Oliveira, Jose Henrique M.; Vannier-Santos, Marcos A.; Galina, Antonio; Oliveira, Pedro L.; Oliveira, Marcus F.

    2009-01-01

    Background Hematophagy poses a challenge to blood-feeding organisms since products of blood digestion can exert cellular deleterious effects. Mitochondria perform multiple roles in cell biology acting as the site of aerobic energy-transducing pathways, and also an important source of reactive oxygen species (ROS), modulating redox metabolism. Therefore, regulation of mitochondrial function should be relevant for hematophagous arthropods. Here, we investigated the effects of blood-feeding on flight muscle (FM) mitochondria from the mosquito Aedes aegypti, a vector of dengue and yellow fever. Methodology/Principal Findings Blood-feeding caused a reversible reduction in mitochondrial oxygen consumption, an event that was parallel to blood digestion. These changes were most intense at 24 h after blood meal (ABM), the peak of blood digestion, when oxygen consumption was inhibited by 68%. Cytochromes c and a+a3 levels and cytochrome c oxidase activity of the electron transport chain were all reduced at 24 h ABM. Ultrastructural and molecular analyses of FM revealed that mitochondria fuse upon blood meal, a condition related to reduced ROS generation. Consistently, BF induced a reversible decrease in mitochondrial H2O2 formation during blood digestion, reaching their lowest values at 24 h ABM where a reduction of 51% was observed. Conclusion Blood-feeding triggers functional and structural changes in hematophagous insect mitochondria, which may represent an important adaptation to blood feeding. PMID:19924237

  19. Dengue knowledge and practices and their impact on Aedes aegypti populations in Kamphaeng Phet, Thailand.

    PubMed

    Koenraadt, Constantianus J M; Tuiten, Wieteke; Sithiprasasna, Ratana; Kijchalao, Udom; Jones, James W; Scott, Thomas W

    2006-04-01

    A knowledge, attitude, and practice (KAP) survey and an extensive entomologic survey were conducted in two sub-districts of Kamphaeng Phet province, Thailand, to test the hypothesis that correct dengue knowledge and practice reduce dengue vector populations. We found a negative association between respondents' knowledge of preventive measures and the number of unprotected containers in and around their houses. Knowledge of development sites was positively associated with unprotected containers. No relationships existed between knowledge of dengue and adult mosquito reduction practices. A higher number of unprotected containers increased the likelihood of the house being infested with one or more adult Aedes aegypti. Surprisingly, houses of respondents that used mosquito coils or had screening on doors and windows were significantly more likely to be infested (odds ratio =2.0) with adult Ae. aegypti. We conclude that there is a direct link between knowledge on dengue prevention and container protection practices, whereas measures against adult mosquitoes are used only when people experience a mosquito nuisance problem. PMID:16607007

  20. Multiple Modes of Action of the Squamocin in the Midgut Cells of Aedes aegypti Larvae.

    PubMed

    da Silva Costa, Marilza; de Paula, Sérgio Oliveira; Martins, Gustavo Ferreira; Zanuncio, José Cola; Santana, Antônio Euzébio Goulart; Serrão, José Eduardo

    2016-01-01

    Annonaceous acetogenins are botanical compounds with good potential for use as insecticides. In the vector, Aedes aegypti (L.) (Diptera: Culicidae), squamocin (acetogenin) has been reported to be a larvicide and cytotoxic, but the modes of action of this molecule are still poorly understood. This study evaluated the changes in the cell morphology, and in the expression of genes, for autophagy (Atg1 and Atg8), for membrane ion transporter V-ATPase, and for water channel aquaporin-4 (Aqp4) in the midgut of A. aegypti larvae exposed to squamocin from Annona mucosa Jacq. (Annonaceae). Squamocin showed cytotoxic action with changes in the midgut epithelium and digestive cells of A. aegypti larvae, increase in the expression for autophagy gene Atg1 and Atg8, decrease in the expression of V-ATPase, decrease in the expression of Aqp4 gene in LC20 and inhibition of Apq4 genes in the midgut of this vector in LC50. These multiple modes of action for squamocin are described for the first time in insects, and they are important because different sites of action of squamocin from A. mucosa may reduce the possibility of resistance of A. aegypti to this molecule. PMID:27532504

  1. Structural Insight into the Mechanism of Substrate Specificity of Aedes Kynurenine Aminotransferase

    SciTech Connect

    Han,Q.; Gao, Y.; Robinson, H.; Li, J.

    2008-01-01

    Aedes aegypti kynurenine aminotransferase (AeKAT) is a multifunctional aminotransferase. It catalyzes the transamination of a number of amino acids and uses many biologically relevant a-keto acids as amino group acceptors. AeKAT also is a cysteine S-conjugate {beta}-lyase. The most important function of AeKAT is the biosynthesis of kynurenic acid, a natural antagonist of NMDA and {alpha}7-nicotinic acetylcholine receptors. Here, we report the crystal structures of AeKAT in complex with its best amino acid substrates, glutamine and cysteine. Glutamine is found in both subunits of the biological dimer, and cysteine is found in one of the two subunits. Both substrates form external aldemines with pyridoxal 5-phosphate in the structures. This is the first instance in which one pyridoxal 5-phosphate enzyme has been crystallized with cysteine or glutamine forming external aldimine complexes, cysteinyl aldimine and glutaminyl aldimine. All the units with substrate are in the closed conformation form, and the unit without substrate is in the open form, which suggests that the binding of substrate induces the conformation change of AeKAT. By comparing the active site residues of the AeKAT-cysteine structure with those of the human KAT I-phenylalanine structure, we determined that Tyr286 in AeKAT is changed to Phe278 in human KAT I, which may explain why AeKAT transaminates hydrophilic amino acids more efficiently than human KAT I does.

  2. Aedes hensilli as a Potential Vector of Chikungunya and Zika Viruses

    PubMed Central

    Ledermann, Jeremy P.; Guillaumot, Laurent; Yug, Lawrence; Saweyog, Steven C.; Tided, Mary; Machieng, Paul; Pretrick, Moses; Marfel, Maria; Griggs, Anne; Bel, Martin; Duffy, Mark R.; Hancock, W. Thane; Ho-Chen, Tai; Powers, Ann M.

    2014-01-01

    An epidemic of Zika virus (ZIKV) illness that occurred in July 2007 on Yap Island in the Federated States of Micronesia prompted entomological studies to identify both the primary vector(s) involved in transmission and the ecological parameters contributing to the outbreak. Larval and pupal surveys were performed to identify the major containers serving as oviposition habitat for the likely vector(s). Adult mosquitoes were also collected by backpack aspiration, light trap, and gravid traps at select sites around the capital city. The predominant species found on the island was Aedes (Stegomyia) hensilli. No virus isolates were obtained from the adult field material collected, nor did any of the immature mosquitoes that were allowed to emerge to adulthood contain viable virus or nucleic acid. Therefore, laboratory studies of the probable vector, Ae. hensilli, were undertaken to determine the likelihood of this species serving as a vector for Zika virus and other arboviruses. Infection rates of up to 86%, 62%, and 20% and dissemination rates of 23%, 80%, and 17% for Zika, chikungunya, and dengue-2 viruses respectively, were found supporting the possibility that this species served as a vector during the Zika outbreak and that it could play a role in transmitting other medically important arboviruses. PMID:25299181

  3. Stormwater Drains and Catch Basins as Sources for Production of Aedes aegypti and Culex quinquefasciatus

    PubMed Central

    Arana-Guardia, Roger; Baak-Baak, Carlos M.; Loroño-Pino, María Alba; Machain-Williams, Carlos; Beaty, Barry J.; Eisen, Lars; García-Rejón, Julián E.

    2014-01-01

    We present data showing that structures serving as drains and catch basins for stormwater are important sources for production of the mosquito arbovirus vectors Aedes aegypti and Culex quinquefasciatus in Mérida City, México. We examined 1,761 stormwater drains – located in 45 different neighborhoods spread across the city – over dry and wet seasons from March 2012–March 2013. Of the examined stormwater drains, 262 (14.9%) held water at the time they were examined and 123 yielded mosquito immatures. In total, we collected 64,560 immatures representing nine species. The most commonly encountered species were Cx. quinquefasciatus (n=39,269) and Ae. aegypti (n=23,313). Ae. aegypti and Cx. quinquefasciatus were collected during all 11 months when we found water-filled stormwater drains, and both were found in stormwater drains located throughout Mérida City. We also present data for associations between structural characteristics of stormwater drains or water-related characteristics and the abundance of mosquito immatures. In conclusion, stormwater drains produce massive numbers of Ae. aegypti and Cx. quinquefasciatus across Mérida City, both in the wet and dry seasons, and represent non-residential development sites that should be strongly considered for inclusion in the local mosquito surveillance and control program. PMID:24582840

  4. Plant essential oils affect the toxicities of carbaryl and permethrin against Aedes aegypti (Diptera: Culicidae).

    PubMed

    Tong, Fan; Bloomquist, Jeffrey R

    2013-07-01

    ABSTRACT Phytochemicals have been considered as alternatives for conventional pesticides because of their low mammalian toxicity and environmental safety. They usually display less potent insecticidal effects than synthetic compounds, but may express as yet unknown modes of action. In the current study, we evaluated 14 plant essential oils for their toxicities and synergistic effects with carbaryl and permethrin against fourth instars of Aedes aegypti (L.) as well as 5-7-d-old adults. Six essential oils showed significant synergistic effects with carbaryl at 10-50 mg/liter, but paradoxically all of them decreased the toxicity of permethrin against Ae. aegypti larvae. None showed toxicity or synergistic effects on Ae. aegypti adults, at doses up to 2,000 ng/ insect. The six essential oils displaying synergistic effects in Ae. aegypti larvae inhibited the in vitro activities of cytochrome P450 monooxygenases and carboxylesterases in the low milligram per liter range. The data indicated that cytochrome P450 monooxygenases and carboxylesterase were probably targets for these natural synergists. Thus, the mechanism of synergism was most likely inhibition of metabolism and not interacting target site effects. PMID:23926781

  5. Multiple Modes of Action of the Squamocin in the Midgut Cells of Aedes aegypti Larvae

    PubMed Central

    de Paula, Sérgio Oliveira; Martins, Gustavo Ferreira; Zanuncio, José Cola

    2016-01-01

    Annonaceous acetogenins are botanical compounds with good potential for use as insecticides. In the vector, Aedes aegypti (L.) (Diptera: Culicidae), squamocin (acetogenin) has been reported to be a larvicide and cytotoxic, but the modes of action of this molecule are still poorly understood. This study evaluated the changes in the cell morphology, and in the expression of genes, for autophagy (Atg1 and Atg8), for membrane ion transporter V-ATPase, and for water channel aquaporin-4 (Aqp4) in the midgut of A. aegypti larvae exposed to squamocin from Annona mucosa Jacq. (Annonaceae). Squamocin showed cytotoxic action with changes in the midgut epithelium and digestive cells of A. aegypti larvae, increase in the expression for autophagy gene Atg1 and Atg8, decrease in the expression of V-ATPase, decrease in the expression of Aqp4 gene in LC20 and inhibition of Apq4 genes in the midgut of this vector in LC50. These multiple modes of action for squamocin are described for the first time in insects, and they are important because different sites of action of squamocin from A. mucosa may reduce the possibility of resistance of A. aegypti to this molecule. PMID:27532504

  6. Structure of hermes integrations in the germline of the yellow fever mosquito, Aedes aegypti.

    PubMed

    Jasinskiene, N; Coates, C J; James, A A

    2000-02-01

    The Hermes transposable element is derived from the house fly, Musca domestica, and can incorporate into the germline of the yellow fever mosquito, Aedes aegypti. Preliminary Southern analyses indicated that Hermes integrated along with the marker gene into the mosquito genomic DNA. Here we show that Hermes integrations are accompanied by the integration of the donor plasmid as well. In addition, breaks in the donor plasmid DNAs do not occur precisely, or at the end of the terminal inverted repeats, and are accompanied by small deletions in the plasmids. Furthermore, integrations do not cause the typical 8-bp duplications of the target site DNA. No integrations are observed in the absence of a source of Hermes transposase. The Hermes transposase clearly did not catalyse precise cut-and-paste transposition in these transformed lines. It may have integrated the transposon through general recombination or through a partial replicative transposition mechanism. The imprecision of Hermes integration may result from interactions of the transposase with an endogenous hAT-like element in the mosquito genome. PMID:10672066

  7. Spatial analysis of Aedes aegypti immatures in Northern Argentina: clusters and temporal instability.

    PubMed

    Garelli, Fernando M; Espinosa, Manuel O; Gürtler, Ricardo E

    2013-12-01

    The objective of this study was to analyze the spatio-temporal patterns of Aedes aegypti immatures based on four entomological surveys that inspected over 6000 households in a large neighborhood of the city of Clorinda between 2007 and 2008. Global and local spatial point pattern analyses of immature presence or absence, habitat quality (estimated using a previously obtained statistical model) and pupal production were performed. Global analyses showed aggregation of both infestation and habitat quality up to 10 times bigger than previously described, ranging from 150 to 400m between surveys. Pupal production was also clustered but at smaller scales than infestation presence/absence. The location of the clusters was temporally unstable between surveys. There was no spatial structure related to the control strategy; lots treated with temephos and lots uninspected (i.e., closed or refusing) were randomly distributed. These results suggest a combination of exogenous (the aggregation of better quality habitats) and endogenous (dispersal) processes explaining the observed patterns of larger-scale infestation. A spatial targeting strategy at the neighborhood scale would not be as cost-effective in Clorinda as in other sites where stable smaller-scale clusters permit the identification of key premises. PMID:23911331

  8. Differential transcription profiles in Aedes aegypti detoxification genes after temephos selection.

    PubMed

    Saavedra-Rodriguez, K; Strode, C; Flores, A E; Garcia-Luna, S; Reyes-Solis, G; Ranson, H; Hemingway, J; Black, W C

    2014-04-01

    The mosquito Aedes aegypti is the main vector of Dengue and Yellow Fever flaviviruses. The organophosphate insecticide temephos is a larvicide that is used globally to control Ae. aegypti populations; many of which have in turn evolved resistance. Target site alteration in the acetylcholine esterase of this species has not being identified. Instead, we tracked changes in transcription of metabolic detoxification genes using the Ae. aegypti 'Detox Chip' microarray during five generations of temephos selection. We selected for temephos resistance in three replicates in each of six collections, five from Mexico, and one from Peru. The response to selection was tracked in terms of lethal concentrations. Uniform upregulation was seen in the epsilon class glutathione-S-transferase (eGST) genes in strains from Mexico prior to laboratory selection, while eGSTs in the Iquitos Peru strain became upregulated after five generations of temephos selection. While expression of many carboxyl/cholinesterase esterase (CCE) genes increased with selection, no single esterase was consistently upregulated and this same pattern was noted in the cytochrome P450 monooxygenase (CYP) genes and in other genes involved in reduction or oxidation of xenobiotics. Bioassays using glutathione-S-transferase (GST), CCE and CYP inhibitors suggest that various CCEs instead of GSTs are the main metabolic mechanism conferring resistance to temephos. We show that temephos-selected strains show no cross resistance to permethrin and that genes associated with temephos selection are largely independent of those selected with permethrin in a previous study. PMID:24299217

  9. Aedes hensilli as a potential vector of Chikungunya and Zika viruses.

    PubMed

    Ledermann, Jeremy P; Guillaumot, Laurent; Yug, Lawrence; Saweyog, Steven C; Tided, Mary; Machieng, Paul; Pretrick, Moses; Marfel, Maria; Griggs, Anne; Bel, Martin; Duffy, Mark R; Hancock, W Thane; Ho-Chen, Tai; Powers, Ann M

    2014-10-01

    An epidemic of Zika virus (ZIKV) illness that occurred in July 2007 on Yap Island in the Federated States of Micronesia prompted entomological studies to identify both the primary vector(s) involved in transmission and the ecological parameters contributing to the outbreak. Larval and pupal surveys were performed to identify the major containers serving as oviposition habitat for the likely vector(s). Adult mosquitoes were also collected by backpack aspiration, light trap, and gravid traps at select sites around the capital city. The predominant species found on the island was Aedes (Stegomyia) hensilli. No virus isolates were obtained from the adult field material collected, nor did any of the immature mosquitoes that were allowed to emerge to adulthood contain viable virus or nucleic acid. Therefore, laboratory studies of the probable vector, Ae. hensilli, were undertaken to determine the likelihood of this species serving as a vector for Zika virus and other arboviruses. Infection rates of up to 86%, 62%, and 20% and dissemination rates of 23%, 80%, and 17% for Zika, chikungunya, and dengue-2 viruses respectively, were found supporting the possibility that this species served as a vector during the Zika outbreak and that it could play a role in transmitting other medically important arboviruses. PMID:25299181

  10. Does Autocthonous Primary Production Influence Oviposition by Aedes japonicus japonicus (Diptera: Culicidae) in Container Habitats?

    PubMed Central

    LORENZ, AMANDA R.; WALKER, EDWARD D.; KAUFMAN, MICHAEL G.

    2014-01-01

    Aedes (Finlaya) japonicus japonicus (Theobald) (Diptera: Culicidae) is recently invasive in North America and has expanded its range rapidly since 1998. Throughout its native and expanded range, Ae. j. japonicus larvae are commonly observed in many types of natural and artificial water-filled containers that vary in organic matter content and exposure to sunlight. Larvae are most often found in containers with decaying leaf material or algae, and we postulated that the added autocthonous primary production from algae could be both an important food source for larvae and an influential oviposition attractant to adult Ae. j. japonicus. We tested this hypothesis by placing plastic containers with varied levels of shading to manipulate algal density in the field, and then monitored oviposition by natural populations of Ae. j. japonicus. Over 99% of larvae hatching from eggs laid on the walls of our containers were Ae. j. japonicus, indicating that this species is a dominant colonizer of artificial containers in the study areas. Although full shading treatments effectively reduced algal biomass (significant reduction in chlorophyll a levels), at only one of three sites did this appear to affect Ae. j. japonicus oviposition. We conclude that algae in larval habitats are not a major factor in oviposition choices of adult Ae. j. japonicus females except when in situ primary production is high enough to substantially alter overall organic matter content cues. PMID:23427654

  11. The Dengue Virus Mosquito Vector Aedes aegypti at High Elevation in México

    PubMed Central

    Lozano-Fuentes, Saul; Hayden, Mary H.; Welsh-Rodriguez, Carlos; Ochoa-Martinez, Carolina; Tapia-Santos, Berenice; Kobylinski, Kevin C.; Uejio, Christopher K.; Zielinski-Gutierrez, Emily; Monache, Luca Delle; Monaghan, Andrew J.; Steinhoff, Daniel F.; Eisen, Lars

    2012-01-01

    México has cities (e.g., México City and Puebla City) located at elevations > 2,000 m and above the elevation ceiling below which local climates allow the dengue virus mosquito vector Aedes aegypti to proliferate. Climate warming could raise this ceiling and place high-elevation cities at risk for dengue virus transmission. To assess the elevation ceiling for Ae. aegypti and determine the potential for using weather/climate parameters to predict mosquito abundance, we surveyed 12 communities along an elevation/climate gradient from Veracruz City (sea level) to Puebla City (∼2,100 m). Ae. aegypti was commonly encountered up to 1,700 m and present but rare from 1,700 to 2,130 m. This finding extends the known elevation range in México by > 300 m. Mosquito abundance was correlated with weather parameters, including temperature indices. Potential larval development sites were abundant in Puebla City and other high-elevation communities, suggesting that Ae. aegypti could proliferate should the climate become warmer. PMID:22987656

  12. Differential transcription profiles in Aedes aegypti detoxification genes following temephos selection

    PubMed Central

    Saavedra-Rodriguez, Karla; Strode, Clare; Flores, Adriana E.; Garcia-Luna, Selene; Reyes-Solis, Guadalupe; Ranson, Hilary; Hemingway, Janet; Black, William C.

    2014-01-01

    The mosquito Aedes aegypti is the main vector of Dengue and Yellow Fever flaviviruses. The organophosphate insecticide temephos is a larvicide that is used globally to control Ae. aegypti populations; many of which have in turn evolved resistance. Target site alteration in the acetylcholine esterase of this species has not being identified. Instead, we tracked changes in transcription of metabolic detoxification genes using the Ae. aegypti ‘Detox Chip’ microarray during five generations of temephos selection. We selected for temephos resistance in three replicates in each of six collections, five from México, and one from Perú. The response to selection was tracked in terms of lethal concentrations (LC50). Uniform upregulation was seen in the epsilon class glutathione-S-transferase genes (eGSTs) in strains from México prior to laboratory selection, while eGSTs in the Iquitos Perú strain became upregulated following five generations of temephos selection. While expression of many esterase genes (CCE) increased with selection, no single esterase was consistently upregulated and this same pattern was noted in the cytochrome P450 genes (CYP) and in other genes involved in reduction or oxidation of xenobiotics. Bioassays using GST, CCE and CYP inhibitors suggest that various CCE instead of GSTs are the main metabolic mechanism conferring resistance to temephos. We show that temephos selected strains show no cross resistance to permethrin and that genes associated with temephos selection are largely independent of those selected with permethrin in a previous study. PMID:24299217

  13. QTL Mapping of Genome Regions Controlling Temephos Resistance in Larvae of the Mosquito Aedes aegypti

    PubMed Central

    Reyes-Solis, Guadalupe del Carmen; Saavedra-Rodriguez, Karla; Suarez, Adriana Flores; Black, William C.

    2014-01-01

    Introduction The mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Temephos is an organophosphate insecticide used globally to suppress Ae. aegypti larval populations but resistance has evolved in many locations. Methodology/Principal Findings Quantitative Trait Loci (QTL) controlling temephos survival in Ae. aegypti larvae were mapped in a pair of F3 advanced intercross lines arising from temephos resistant parents from Solidaridad, México and temephos susceptible parents from Iquitos, Peru. Two sets of 200 F3 larvae were exposed to a discriminating dose of temephos and then dead larvae were collected and preserved for DNA isolation every two hours up to 16 hours. Larvae surviving longer than 16 hours were considered resistant. For QTL mapping, single nucleotide polymorphisms (SNPs) were identified at 23 single copy genes and 26 microsatellite loci of known physical positions in the Ae. aegypti genome. In both reciprocal crosses, Multiple Interval Mapping identified eleven QTL associated with time until death. In the Solidaridad×Iquitos (SLD×Iq) cross twelve were associated with survival but in the reciprocal IqxSLD cross, only six QTL were survival associated. Polymorphisms at acetylcholine esterase (AchE) loci 1 and 2 were not associated with either resistance phenotype suggesting that target site insensitivity is not an organophosphate resistance mechanism in this region of México. Conclusions/Significance Temephos resistance is under the control of many metabolic genes of small effect and dispersed throughout the Ae. aegypti genome. PMID:25330200

  14. Interpopulation differences in competitive effect and response of the mosquito Aedes aegypti and resistance to invasion by a superior competitor

    PubMed Central

    Juliano, S. A.

    2012-01-01

    Geographic variation in species interactions can have major effects on species distributions and can be important for the resistance of resident communities to invasive species. We tested the hypothesis that coexistence or replacement of a resident North American mosquito Aedes aegypti with the invasive Aedes albopictus is affected by interpopulation variation in the inherent competitive ability of A. aegypti and variation in the fecundity–size relationship. We postulated that such variation creates differential population-level outcomes of competition with A. albopictus. We compared competitive abilities of eight North American populations of A. aegypti, four populations sympatric to A. albopictus, and four populations allopatric to A. albopictus. Competition among larvae from each A. aegypti population and a single A. albopictus population was tested in laboratory microcosms in a response-surface design. We found origin of A. aegypti influences its competitive response to competition from A. albopictus and competitive effect on A. albopictus. A. aegypti from allopatric sites preformed better in competition with A. albopictus than did A. aegypti from sympatric sites because they had a stronger average effect on A. albopictus. This average was strongly influenced by the allopatric population from Miami. Competitive effect and response were uncorrelated among populations, indicating inconsistent ranking of A. aegypti in competitive effect and response. Although A. albopictus is generally a superior competitor to A. aegypti, a stronger competitive effect of particular A. aegypti populations on invading A. albopictus may contribute to competition-mediated biotic resistance to the invader. These results suggest that interpopulation variation in competitive ability of A. aegypti may contribute to failure of A. albopictus to invade parts of the southeastern United States and offer evidence of a contribution to biotic resistance by an inferior competitor. Geographic

  15. Influence of resource levels, organic compounds, and laboratory colonization on interspecific competition between the Asian tiger mosquito (Aedes albopictus) and the southern house mosquito (Culex quinquefasciatus)

    PubMed Central

    Allgood, David W.; Yee, Donald A.

    2013-01-01

    The mosquitoes Aedes albopictus (Skuse) and Culex quinquefasciatus (Say) (Diptera:Culicidae) are common inhabitants of tyres and other artificial containers, which constitute important peridomestic mosquito breeding habitats. We tested the hypotheses that interspecific resource competition between the larvae of these species is asymmetrical, that the concentration of chemicals associated with decomposing detritus affects their competitive outcome, and that wild and colonized strains of Cx. quinquefasciatus are affected differently by competition with Ae. albopictus. We conducted two laboratory competition experiments wherein we measured survivorship and estimated population growth (λ’) of both species under multiple mixed-species densities. Under varying resource levels, competition was asymmetrical with Ae. albopictus causing competitive reductions or exclusions of Cx. quinquefasciatus under limited resources. In a second experiment, which used both wild and colonized strains of Cx. quinquefasciatus, organic chemical compounds associated with decomposing detritus did not affect the competitive outcome. The colonized strain of Cx. quinquefasciatus had greater survivorship, adult mass, and faster development times than the wild strain, but both strains were similarly affected by competition with Ae. albopictus. Competition between these species may have important consequences for vector population dynamics, especially in areas where tyres and artificial containers constitute the majority of mosquito breeding habitats. PMID:24444185

  16. The global compendium of Aedes aegypti and Ae. albopictus occurrence

    PubMed Central

    Kraemer, Moritz U. G.; Sinka, Marianne E.; Duda, Kirsten A.; Mylne, Adrian; Shearer, Freya M.; Brady, Oliver J.; Messina, Jane P.; Barker, Christopher M.; Moore, Chester G.; Carvalho, Roberta G.; Coelho, Giovanini E.; Van Bortel, Wim; Hendrickx, Guy; Schaffner, Francis; Wint, G. R. William; Elyazar, Iqbal R. F.; Teng, Hwa-Jen; Hay, Simon I.

    2015-01-01

    Aedes aegypti and Ae. albopictus are the main vectors transmitting dengue and chikungunya viruses. Despite being pathogens of global public health importance, knowledge of their vectors’ global distribution remains patchy and sparse. A global geographic database of known occurrences of Ae. aegypti and Ae. albopictus between 1960 and 2014 was compiled. Herein we present the database, which comprises occurrence data linked to point or polygon locations, derived from peer-reviewed literature and unpublished studies including national entomological surveys and expert networks. We describe all data collection processes, as well as geo-positioning methods, database management and quality-control procedures. This is the first comprehensive global database of Ae. aegypti and Ae. albopictus occurrence, consisting of 19,930 and 22,137 geo-positioned occurrence records respectively. Both datasets can be used for a variety of mapping and spatial analyses of the vectors and, by inference, the diseases they transmit. PMID:26175912

  17. Cytotoxicity of piperamides towards Aedes aegypti (Diptera: Culicidae).

    PubMed

    Maleck, Marise; Ferreira, Bruna; Mallet, Jacenir; Guimarães, Anthony; Kato, Massuo

    2014-03-01

    The effectiveness of the amides piplartine and piperlonguminine isolated from Piper species for controlling L3 and L4 of Aedes aegypti (L.) was assessed through bioassays at concentrations ranging from 1 to 300 g/l ml. Piplartine reduced the mosquito development period and caused larval mortality only at concentrations > 100 microg/ml, whereas piperlonguminine resulted in an extended period of mosquito development (10 microg/ml) and caused 100% larval mortality (30 microg/ml) within 24 h. The toxicity and cytotoxic effects of piperlonguminine on epithelial cells of the digestive system of Ae. aegypti were viewed using transmission electron microscopy, which indicated vacuolization of cytoplasm, mitochondrial swelling and leaking of nuclear material. Piperlonguminine was the more effective amide, showing toxic activity with LD50 of approximately 12 microg/ml against the larvae of Ae. aegypti. PMID:24724297

  18. Plaque Production by Arboviruses in Singh's Aedes albopictus Cells

    PubMed Central

    Yunker, C. E.; Cory, J.

    1975-01-01

    We report plaquing tests of 124 virus strains, mostly arboviruses of 21 serological groups, in Singh's line of Aedes albopictus cells. Thirty of these plaqued; all were arboviruses of six groups and were known or presumed to be mosquito borne. Failing to plaque were 86 strains of arboviruses, mostly tick borne, two strains of insect pathogens, and six animal viruses not classified as arboviruses. Among mosquito-borne agents, plaquing ability appeared related to serological classification. California group and most A-group viruses failed to plaque, but nearly all members of B and Bunyamwera groups readily plaqued. Within serological group B, 14 of 16 mosquito-borne agents plaqued, but none of 13 tick-borne or vector-unassociated viruses did so. Some implications of these results for recognition and classification of arboviruses are discussed. Images PMID:234160

  19. Larvicidal activity of Tagetes minuta (marigold) toward Aedes aegypti.

    PubMed

    Green, M M; Singer, J M; Sutherland, D J; Hibben, C R

    1991-06-01

    The steam distilled oils of 3 species of marigold, Tagetes patula, T. erecta and T. minuta, were tested for larvicidal activity toward third instar Aedes aegypti; activity at 10 ppm was demonstrated only for T. minuta. The larvicidal property of the whole oil dispersed in water persisted for at least 9 days. The terpene, ocimenone, which is a part of the whole oil, was found to be larvicidal only at a higher concentration than the whole oil and to lose its activity within 24 h after dispersal in water. These results suggest a potential utilization of oil of T. minuta or its components for the control of Ae. aegypti and other species of mosquitoes. PMID:1895085

  20. Genome sequence of Aedes aegypti, a major arbovirus vector.

    PubMed

    Nene, Vishvanath; Wortman, Jennifer R; Lawson, Daniel; Haas, Brian; Kodira, Chinnappa; Tu, Zhijian Jake; Loftus, Brendan; Xi, Zhiyong; Megy, Karyn; Grabherr, Manfred; Ren, Quinghu; Zdobnov, Evgeny M; Lobo, Neil F; Campbell, Kathryn S; Brown, Susan E; Bonaldo, Maria F; Zhu, Jingsong; Sinkins, Steven P; Hogenkamp, David G; Amedeo, Paolo; Arensburger, Peter; Atkinson, Peter W; Bidwell, Shelby; Biedler, Jim; Birney, Ewan; Bruggner, Robert V; Costas, Javier; Coy, Monique R; Crabtree, Jonathan; Crawford, Matt; Debruyn, Becky; Decaprio, David; Eiglmeier, Karin; Eisenstadt, Eric; El-Dorry, Hamza; Gelbart, William M; Gomes, Suely L; Hammond, Martin; Hannick, Linda I; Hogan, James R; Holmes, Michael H; Jaffe, David; Johnston, J Spencer; Kennedy, Ryan C; Koo, Hean; Kravitz, Saul; Kriventseva, Evgenia V; Kulp, David; Labutti, Kurt; Lee, Eduardo; Li, Song; Lovin, Diane D; Mao, Chunhong; Mauceli, Evan; Menck, Carlos F M; Miller, Jason R; Montgomery, Philip; Mori, Akio; Nascimento, Ana L; Naveira, Horacio F; Nusbaum, Chad; O'leary, Sinéad; Orvis, Joshua; Pertea, Mihaela; Quesneville, Hadi; Reidenbach, Kyanne R; Rogers, Yu-Hui; Roth, Charles W; Schneider, Jennifer R; Schatz, Michael; Shumway, Martin; Stanke, Mario; Stinson, Eric O; Tubio, Jose M C; Vanzee, Janice P; Verjovski-Almeida, Sergio; Werner, Doreen; White, Owen; Wyder, Stefan; Zeng, Qiandong; Zhao, Qi; Zhao, Yongmei; Hill, Catherine A; Raikhel, Alexander S; Soares, Marcelo B; Knudson, Dennis L; Lee, Norman H; Galagan, James; Salzberg, Steven L; Paulsen, Ian T; Dimopoulos, George; Collins, Frank H; Birren, Bruce; Fraser-Liggett, Claire M; Severson, David W

    2007-06-22

    We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species. PMID:17510324

  1. Larvicidal activity of Tagetes erecta against Aedes aegypti.

    PubMed

    Marques, Márcia M M; Morais, Selene M; Vieira, Icaro G P; Vieira, Mariano G S; Raquel, Ana; Silva, A; De Almeida, Raimundo Rafael; Guedes, Maria Izabel F

    2011-06-01

    The aim of this study was to evaluate the activity of essential oil from Tagetes erecta against 3rd instars of Aedes aegypti and to determine the amounts of larvicidal thiophenes in all plant tissues. The oil obtained by steam distillation and analyzed by gas chromatography/mass spectrometry showed 14 compounds. The main compounds were piperitone (45.72%), D-limonene (9.67%), and piperitenone (5.89%). The essential oil was active against larvae of Ae. aegypti, with LC50 of 79.78 microg/ml and LC90 of 100.84 microg/ml. The larvicidal thiophene contents were higher in the roots and flowers as demonstrated by high-performance liquid chromatography analysis. Thus, T. erecta constitutes a good source of varied compounds showing larvicidal activity against Ae. aegypti. PMID:21805850

  2. The complete mitochondrial DNA genome of Aedes vigilax (Diptera: Culicidae).

    PubMed

    Hardy, C M; Court, L N; Morgan, M J

    2016-07-01

    The complete mitochondrial genomes of two main clades of the medically significant saltmarsh mosquito Aedes vigilax Skuse (Diptera: Culicidae) were obtained using combined Illumina and Sanger sequencing. The two 15,877 bp circular genomes share 99.0% nucleotide identity and encode 37 genes with identical gene arrangement similar to previously published Culicidae species with a non-coding A + T rich region between rns and tRNA-Ile. Protein initiation codon is ATN apart from ND5 (GTG) and COX1 (TCG). Eight protein-coding genes encode full TAA stop codon, while five are completed by mRNA polyadenylation. Typical cloverleaf structures containing DHU and TΨC stem and loops can be inferred for all 22 tRNAs. PMID:26099979

  3. Repellents Inhibit P450 Enzymes in Stegomyia (Aedes) aegypti

    PubMed Central

    Jaramillo Ramirez, Gloria Isabel; Logan, James G.; Loza-Reyes, Elisa; Stashenko, Elena; Moores, Graham D.

    2012-01-01

    The primary defence against mosquitoes and other disease vectors is often the application of a repellent. Despite their common use, the mechanism(s) underlying the activity of repellents is not fully understood, with even the mode of action of DEET having been reported to be via different mechanisms; e.g. interference with olfactory receptor neurones or actively detected by olfactory receptor neurones on the antennae or maxillary palps. In this study, we discuss a novel mechanism for repellence, one of P450 inhibition. Thirteen essential oil extracts from Colombian plants were assayed for potency as P450 inhibitors, using a kinetic fluorometric assay, and for repellency using a modified World Health Organisation Pesticide Evaluations Scheme (WHOPES) arm-in cage assay with Stegomyia (Aedes) aegypti mosquitoes. Bootstrap analysis on the inhibition analysis revealed a significant correlation between P450-inhibition and repellent activity of the oils. PMID:23152795

  4. Toxicities of certain larvicides to resistant and susceptible Aedes aegypti

    PubMed Central

    Klassen, W.; Keppler, W. J.; Kitzmiller, J. B.

    1965-01-01

    In a study of the toxicological characteristics of dieldrin-resistant and DDT-resistant strains of Aedes aegypti, combined with an evaluation of certain larvicides, 14 cyclodienes, 13 DDT-type compounds, 18 organophosphorus compounds, several carbamates and a number of other compounds were tested against larvae of A. aegypti. Telodrin and GC-9160 proved to be toxic against a highly dieldrin-resistant strain. Against highly DDT-resistant strains the toxicity of DDT could be enhanced by piperonyl butoxide, DMC or WARF, that of deutero-DDT by DMC, and that of methoxychlor by piperonyl butoxide. Prolan and Bulan were found to be slightly less effective than deutero-DDT against highly DDT-resistant strains. Among the more recent organophosphorus compounds found to exceed fenthion in toxicity are AC-52160, Stauffer N-2404, Folithion, Bayer 52957 and SD-7438. The effectiveness of dimethrin could be enhanced with piperonyl butoxide. PMID:5294255

  5. Invasion Biology of Aedes japonicus japonicus (Diptera: Culicidae)

    PubMed Central

    Fonseca, Dina M.

    2014-01-01

    Aedes japonicus japonicus (Theobald) (Diptera: Culicidae) has recently expanded beyond its native range of Japan and Korea into large parts of North America and Central Europe. Population genetic studies begun immediately after the species was detected in North America revealed genetically distinct introductions that subsequently merged, likely contributing to the successful expansion. Interactions, particularly in the larval stage, with other known disease vectors give this invasive subspecies the potential to influence local disease dynamics. Its successful invasion likely does not involve superior direct competitive abilities, but it is associated with the use of diverse larval habitats and a cold tolerance that allows an expanded seasonal activity range in temperate climates. We predict a continued but slower expansion of Ae. j. japonicus in North America and a continued rapid expansion into other areas as this mosquito will eventually be considered a permanent resident of much of North America, Europe, Asia, and parts of Hawaii. PMID:24397520

  6. Epidemiology of tree-hole breeding mosquitoes in the tropical rainforest of Imo State, south-east Nigeria.

    PubMed

    Anosike, Jude C; Nwoke, Bertram E B; Okere, Anthony N; Oku, Ene E; Asor, Joe E; Emmy-Egbe, Ifeyinwa O; Adimike, Desmond A

    2007-01-01

    The study of tree-hole breeding mosquitoes was carried out in the tropical rainforest of Imo State Nigeria (two rural areas and two forest reserves in some parts of Orlu Senatorial Zone) between May-October 2002. Using standard entomological procedures, two macrohabitats (natural tree-holes and bamboo traps) and two microhabitats (leaf axils of cocoyams/pineapples and leaf axils of plantain/banana) were sampled for various mosquito species. Mosquitoes were recovered from all the various biotypes sampled. Types of mosquitoes species encountered, their relative abundance, as well as genera varied significantly during the study (p<0.05). Four genera of mosquitoes: Aedes, Culex, Anopheles and Toxorhynchites were recovered while 16 species of mosquitoes encountered include: Aedes aegypti, Ae. africanus, Ae. simpsoni, Ae. albopictus, Ae. stokesi, Ae. taylori, Ae. apicoargenteus, Culex quinquefasciatus, Cx. nebulosus, Cx. trigripes, Cx. decens, Anopheles gambiae, An. funiestus, An. coustani and Toxorhynchites viridibasis. Most of the mosquitoes showed oviposition preferences for one or more habitats. The presence of Ae. africanus, Ae. simpsoni and Ae. aegypti indicate that the study areas were at risk of yellow fever epidemic. The presence of Anopheles and Culex species ensured endemicity of malaria and filariasis, while the recovery of Ae. albopictus in this region suggests a possible outbreak of dengue fever in future if not properly controlled. PMID:17655174

  7. Effect of triflumuron, a chitin synthesis inhibitor, on Aedes aegypti, Aedes albopictus and Culex quinquefasciatus under laboratory conditions

    PubMed Central

    2013-01-01

    Background Resistance to traditional insecticides represents a threat to the control of disease vectors. The insect growth regulators (IGR) are a potential alternative to control mosquitoes, including resistant populations. The chitin synthesis inhibitors (CSI) are IGRs, which interfere with the insect molting process and represent one major class of compounds against Aedes aegypti populations resistant to the larvicide organophosphate temephos. In the present study, we evaluated the efficacy of the CSI triflumuron on Culex quinquefasciatus, Aedes albopictus and against several Ae. aegypti field populations. Methods The efficacy of triflumuron, against Cx. quinquefasciatus and Ae. albopictus was evaluated with laboratory strains through dose–response assays. Additionaly, this CSI was tested against seven Ae. aegypti field populations exhibiting distinct resistance levels to both temephos and the pyrethroid deltamethrin. Aedes aegypti populations were exposed to both a dose that inhibits 99% of the adult emergence of mosquitoes from the susceptible reference strain, Rockefeller, (EI99 = 3.95 μg/L) and the diagnostic dose (DD), corresponding to twice the EI99. Results Our results indicate that triflumuron was effective in emergence inhibition (EI) of Cx. quinquefasciatus (EI50= 5.28 μg/L; EI90= 12.47 μg/L) and Ae. albopictus (EI50= 1.59 μg/L; EI90= 2.63 μg/L). Triflumuron was also effective against seven Ae. aegypti Brazilian populations resistant to both temephos and deltamethrin. Exposure of all the Ae. aegypti populations to the triflumuron EI99 of the susceptible reference strain, Rockefeller, resulted in complete inhibition of adult emergence, suggesting no cross-resistance among traditional insecticides and this CSI. However, a positive correlation between temephos resistance and tolerance to triflumuron was observed. Conclusion The results suggest that triflumuron represents a potential tool for the control of disease vectors in public

  8. Cumulative mortality of Aedes aegypti larvae treated with compounds.

    PubMed

    Torres, Sandra Maria; Cruz, Nadine Louise Nicolau da; Rolim, Vitor Pereira de Matos; Cavalcanti, Maria Inês de Assis; Alves, Leucio Câmara; Silva Júnior, Valdemiro Amaro da

    2014-06-01

    OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs. PMID:25119939

  9. Cumulative mortality of Aedes aegypti larvae treated with compounds

    PubMed Central

    Torres, Sandra Maria; da Cruz, Nadine Louise Nicolau; Rolim, Vitor Pereira de Matos; Cavalcanti, Maria Inês de Assis; Alves, Leucio Câmara; da Silva, Valdemiro Amaro

    2014-01-01

    OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs. PMID:25119939

  10. Wolbachia Modulates Lipid Metabolism in Aedes albopictus Mosquito Cells

    PubMed Central

    Molloy, Jennifer C.; Sommer, Ulf; Viant, Mark R.

    2016-01-01

    ABSTRACT Certain strains of the intracellular endosymbiont Wolbachia can strongly inhibit or block the transmission of viruses such as dengue virus (DENV) by Aedes mosquitoes, and the mechanisms responsible are still not well understood. Direct infusion and liquid chromatography-Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry-based lipidomics analyses were conducted using Aedes albopictus Aa23 cells that were infected with the wMel and wMelPop strains of Wolbachia in comparison to uninfected Aa23-T cells. Substantial shifts in the cellular lipid profile were apparent in the presence of Wolbachia. Most significantly, almost all sphingolipid classes were depleted, and some reductions in diacylglycerols and phosphatidylcholines were also observed. These lipid classes have previously been shown to be selectively enriched in DENV-infected mosquito cells, suggesting that Wolbachia may produce a cellular lipid environment that is antagonistic to viral replication. The data improve our understanding of the intracellular interactions between Wolbachia and mosquitoes. IMPORTANCE Mosquitoes transmit a variety of important viruses to humans, such as dengue virus and Zika virus. Certain strains of the intracellular bacterial genus called Wolbachia found in or introduced into mosquitoes can block the transmission of viruses, including dengue virus, but the mechanisms responsible are not well understood. We found substantial shifts in the cellular lipid profiles in the presence of these bacteria. Some lipid classes previously shown to be enriched in dengue virus-infected mosquito cells were depleted in the presence of Wolbachia, suggesting that Wolbachia may produce a cellular lipid environment that inhibits mosquito-borne viruses. PMID:26994075

  11. Kappa-casein polymorphisms among cattle breeds and bison herds

    USGS Publications Warehouse

    Cronin, M.A.; Cockett, N.

    1993-01-01

    We identified the HindIII restriction site polymorphism Of kappa-casein in cattle reported by Pinder et al. (Animal Genetics 22, 11, 1991) and found an additonal polymorphism (RsaI) in cattle and bison. The Hin dIII and Rsa I restriction sites were mapped and three haplotypes (alleles) were identified. Preliminary screening of 39 cattle and 71 bison revealed one allele restricted to cattle, one restricted to bison, and one shared by the species. No fixed allelic differences were observed among cattle breeds or among bison herds or subspecies.

  12. [The native domestic animal breeds of Japan].

    PubMed

    Sambraus, H H

    1989-01-01

    During the last decades some domestic animal breeds have spread to all parts of the world. In general, consideration is given to these breeds only; on the other hand, autochthonous breeds of various countries are hardly known. These, however, can be valuable gene-reserves, and moreover, they represent a significant cultural value. In Japan there are several domestic animal breeds which are almost unknown in Central Europe. They are presented verbally and by means of illustration, and their breeding history is dealt with as well. The purpose of this study is to point out the importance of these breeds within the country and to make clear the extent of the danger of their extinction. PMID:2683212

  13. [Progress and countermeasures of Dendrobium officinale breeding].

    PubMed

    Si, Jin-Ping; He, Bo-wei; Yu, Qiao-xian

    2013-02-01

    The standandized cultivation of Chinese medicinal materials is based on variety. With the rapid development of Dendrobium officinale industry and increasing demand of improved varieties, many studies have concentrated on the variety breeding of D. officinale and subsequently achieved remarkable success. This paper systematically expounds the research progress of D. officinale breeding, e. g. the collection and differentiated evaluation for germplasm, theory and practice for variety breeding, tissue culture and efficient production with low-carbon for germchit, and DNA molecular marker-assisted breeding, and then indicates the main problems of the current breeding of D. officinale. Furthermore, the priorities and keys for the further breeding of D. officinale have been pointed out. PMID:23713267

  14. The Efficacy of Some Commercially Available Insect Repellents for Aedes aegypti (Diptera: Culicidae) and Aedes albopictus (Diptera: Culicidae).

    PubMed

    Rodriguez, Stacy D; Drake, Lisa L; Price, David P; Hammond, John I; Hansen, Immo A

    2015-01-01

    Reducing the number of host-vector interactions is an effective way to reduce the spread of vector-borne diseases. Repellents are widely used to protect humans from a variety of protozoans, viruses, and nematodes. DEET (N,N-Diethyl-meta-toluamide), a safe and effective repellent, was developed during World War II. Fear of possible side effects of DEET has created a large market for "natural" DEET-free repellents with a variety of active ingredients. We present a comparative study on the efficacy of eight commercially available products, two fragrances, and a vitamin B patch. The products were tested using a human hand as attractant in a Y-tube olfactometer setup with Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse), both major human disease vectors. We found that Ae. albopictus were generally less attracted to the test subject's hand compared with Ae, aegypti. Repellents with DEET as active ingredient had a prominent repellency effect over longer times and on both species. Repellents containing p-menthane-3,8-diol produced comparable results but for shorter time periods. Some of the DEET-free products containing citronella or geraniol did not have any significant repellency effect. Interestingly, the perfume we tested had a modest repellency effect early after application, and the vitamin B patch had no effect on either species. This study shows that the different active ingredients in commercially available mosquito repellent products are not equivalent in terms of duration and strength of repellency. Our results suggest that products containing DEET or p-menthane-3,8-diol have long-lasting repellent effects and therefore provide good protection from mosquito-borne diseases. PMID:26443777

  15. The Efficacy of Some Commercially Available Insect Repellents for Aedes aegypti (Diptera: Culicidae) and Aedes albopictus (Diptera: Culicidae)

    PubMed Central

    Rodriguez, Stacy D.; Drake, Lisa L.; Price, David P.; Hammond, John I.; Hansen, Immo A.

    2015-01-01

    Reducing the number of host-vector interactions is an effective way to reduce the spread of vector-borne diseases. Repellents are widely used to protect humans from a variety of protozoans, viruses, and nematodes. DEET (N,N-Diethyl-meta-toluamide), a safe and effective repellent, was developed during World War II. Fear of possible side effects of DEET has created a large market for “natural” DEET-free repellents with a variety of active ingredients. We present a comparative study on the efficacy of eight commercially available products, two fragrances, and a vitamin B patch. The products were tested using a human hand as attractant in a Y-tube olfactometer setup with Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse), both major human disease vectors. We found that Ae. albopictus were generally less attracted to the test subject’s hand compared with Ae, aegypti. Repellents with DEET as active ingredient had a prominent repellency effect over longer times and on both species. Repellents containing p-menthane-3,8-diol produced comparable results but for shorter time periods. Some of the DEET-free products containing citronella or geraniol did not have any significant repellency effect. Interestingly, the perfume we tested had a modest repellency effect early after application, and the vitamin B patch had no effect on either species. This study shows that the different active ingredients in commercially available mosquito repellent products are not equivalent in terms of duration and strength of repellency. Our results suggest that products containing DEET or p-menthane-3,8-diol have long-lasting repellent effects and therefore provide good protection from mosquito-borne diseases. PMID:26443777

  16. Genomics-assisted breeding in fruit trees

    PubMed Central

    Iwata, Hiroyoshi; Minamikawa, Mai F.; Kajiya-Kanegae, Hiromi; Ishimori, Motoyuki; Hayashi, Takeshi

    2016-01-01

    Recent advancements in genomic analysis technologies have opened up new avenues to promote the efficiency of plant breeding. Novel genomics-based approaches for plant breeding and genetics research, such as genome-wide association studies (GWAS) and genomic selection (GS), are useful, especially in fruit tree breeding. The breeding of fruit trees is hindered by their long generation time, large plant size, long juvenile phase, and the necessity to wait for the physiological maturity of the plant to assess the marketable product (fruit). In this article, we describe the potential of genomics-assisted breeding, which uses these novel genomics-based approaches, to break through these barriers in conventional fruit tree breeding. We first introduce the molecular marker systems and whole-genome sequence data that are available for fruit tree breeding. Next we introduce the statistical methods for biparental linkage and quantitative trait locus (QTL) mapping as well as GWAS and GS. We then review QTL mapping, GWAS, and GS studies conducted on fruit trees. We also review novel technologies for rapid generation advancement. Finally, we note the future prospects of genomics-assisted fruit tree breeding and problems that need to be overcome in the breeding. PMID:27069395

  17. Breeding without Breeding: Is a Complete Pedigree Necessary for Efficient Breeding?

    PubMed Central

    El-Kassaby, Yousry A.; Cappa, Eduardo P.; Liewlaksaneeyanawin, Cherdsak; Klápště, Jaroslav; Lstibůrek, Milan

    2011-01-01

    Complete pedigree information is a prerequisite for modern breeding and the ranking of parents and offspring for selection and deployment decisions. DNA fingerprinting and pedigree reconstruction can substitute for artificial matings, by allowing parentage delineation of naturally produced offspring. Here, we report on the efficacy of a breeding concept called “Breeding without Breeding” (BwB) that circumvents artificial matings, focusing instead on a subset of randomly sampled, maternally known but paternally unknown offspring to delineate their paternal parentage. We then generate the information needed to rank those offspring and their paternal parents, using a combination of complete (full-sib: FS) and incomplete (half-sib: HS) analyses of the constructed pedigrees. Using a random sample of wind-pollinated offspring from 15 females (seed donors), growing in a 41-parent western larch population, BwB is evaluated and compared to two commonly used testing methods that rely on either incomplete (maternal half-sib, open-pollinated: OP) or complete (FS) pedigree designs. BwB produced results superior to those from the incomplete design and virtually identical to those from the complete pedigree methods. The combined use of complete and incomplete pedigree information permitted evaluating all parents, both maternal and paternal, as well as all offspring, a result that could not have been accomplished with either the OP or FS methods alone. We also discuss the optimum experimental setting, in terms of the proportion of fingerprinted offspring, the size of the assembled maternal and paternal half-sib families, the role of external gene flow, and selfing, as well as the number of parents that could be realistically tested with BwB. PMID:21991342

  18. Influence of Container Size, Location, and Time of Day on Oviposition Patterns of the Dengue Vector, Aedes aegypti, in Thailand

    PubMed Central

    Ponlawat, A.; Edman, J.D.; Scott, T.W.; Vermeylen, F.

    2008-01-01

    Abstract We conducted a study to determine the effect of container size and location on oviposition site selection by Ae. aegypti in large outdoor field enclosures (10 × 10 × 4 m high). There was a strong positive relationship between increasing container diameter, container volume, and water surface area with egg numbers over both high (rainy, July) and low (cool-dry, January) dengue transmission seasons. Location of containers (indoors versus immediately outdoors and underneath houses) did not influence the number of eggs deposited for containers 5–32 cm in diameter in either season. No trends based on container color (black, brown, or grey) were observed. A slight trend with a greater numbers of eggs laid outdoors in the largest containers (42 cm diameter) during the dry season was observed. Three separate models were run using the mixed model procedure in SAS for each container attribute. Controlling for season, time, and date, the most important container attribute predicting total egg numbers was container volume (total capacity) explaining 88% of the variation, followed by water surface area (85%), and container diameter opening (83%). Oviposition peaked in the afternoon at 1600 hrs and 2000 hrs in the dry and rainy seasons, respectively. Few eggs were laid overnight (2000 hrs–0600 hrs). Our results indicate that physical attributes of oviposition sites, such as size, light-dark contrasts, and specular reflectance from water surfaces, play a significant role in oviposition site selection. Key Words: Aedes aegypti—Oviposition—Container dimensions—Site selection—Thailand. PMID:18279006

  19. Comparison of molecular breeding values based on within- and across-breed training in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background Although the efficacy of genomic predictors based on within-breed training looks promising, it is necessary to develop and evaluate across-breed predictors for the technology to be fully applied in the beef industry. The efficacies of genomic predictors trained in one breed and utilized ...

  20. Surveillance, insecticide resistance and control of an invasive Aedes aegypti (Diptera: Culicidae) population in California.

    PubMed

    Cornel, Anthony J; Holeman, Jodi; Nieman, Catelyn C; Lee, Yoosook; Smith, Charles; Amorino, Mark; Brisco, Katherine K; Barrera, Roberto; Lanzaro, Gregory C; Mulligan Iii, F Stephen

    2016-01-01

    The invasion and subsequent establishment in California of Aedes aegypti in 2013 has created new challenges for local mosquito abatement and vector control districts. Studies were undertaken to identify effective and economical strategies to monitor the abundance and spread of this mosquito species as well as for its control. Overall, BG Sentinel (BGS) traps were found to be the most sensitive trap type to measure abundance and spread into new locations. Autocidal-Gravid-Ovitraps (AGO-B), when placed at a site for a week, performed equally to BGS in detecting the presence of female Ae. aegypti. Considering operational cost and our findings, we recommend use of BGS traps for surveillance in response to service requests especially in locations outside the known infestation area. We recommend AGO-Bs be placed at fixed sites, cleared and processed once a week to monitor mosquito abundance within a known infestation area. Long-term high density placements of AGO-Bs were found to show promise as an environmentally friendly trap-kill control strategy. California Ae. aegypti were found to be homozygous for the V1016I mutation in the voltage gated sodium channel gene, which is implicated to be involved in insecticide resistance. This strain originating from Clovis, California was resistant to some pyrethroids but not to deltamethrin in bottle bio-assays. Sentinel cage ultra-low-volume (ULV) trials using a new formulation of deltamethrin (DeltaGard®) demonstrated that it provided some control (average of 56% death in sentinel cages in a 91.4 m spray swath) after a single truck mounted aerial ULV application in residential areas. PMID:27158450

  1. Surveillance, insecticide resistance and control of an invasive Aedes aegypti (Diptera: Culicidae) population in California

    PubMed Central

    Cornel, Anthony J.; Holeman, Jodi; Nieman, Catelyn C.; Lee, Yoosook; Smith, Charles; Amorino, Mark; Brisco, Katherine K.; Barrera, Roberto; Lanzaro, Gregory C.; Mulligan III, F. Stephen

    2016-01-01

    The invasion and subsequent establishment in California of Aedes aegypti in 2013 has created new challenges for local mosquito abatement and vector control districts. Studies were undertaken to identify effective and economical strategies to monitor the abundance and spread of this mosquito species as well as for its control. Overall, BG Sentinel (BGS) traps were found to be the most sensitive trap type to measure abundance and spread into new locations. Autocidal-Gravid-Ovitraps (AGO-B), when placed at a site for a week, performed equally to BGS in detecting the presence of female Ae. aegypti. Considering operational cost and our findings, we recommend use of BGS traps for surveillance in response to service requests especially in locations outside the known infestation area. We recommend AGO-Bs be placed at fixed sites, cleared and processed once a week to monitor mosquito abundance within a known infestation area. Long-term high density placements of AGO-Bs were found to show promise as an environmentally friendly trap-kill control strategy. California Ae. aegypti were found to be homozygous for the V1016I mutation in the voltage gated sodium channel gene, which is implicated to be involved in insecticide resistance. This strain originating from Clovis, California was resistant to some pyrethroids but not to deltamethrin in bottle bio-assays. Sentinel cage ultra-low-volume (ULV) trials using a new formulation of deltamethrin (DeltaGard®) demonstrated that it provided some control (average of 56% death in sentinel cages in a 91.4 m spray swath) after a single truck mounted aerial ULV application in residential areas. PMID:27158450

  2. Evidence for gene duplication in the voltage-gated sodium channel gene of Aedes aegypti

    PubMed Central

    Martins, Ademir Jesus; Brito, Luiz Paulo; Linss, Jutta Gerlinde Birggitt; Rivas, Gustavo Bueno da Silva; Machado, Ricardo; Bruno, Rafaela Vieira; Lima, José Bento Pereira; Valle, Denise; Peixoto, Alexandre Afranio

    2013-01-01

    Background and objectives: Mutations in the voltage-gated sodium channel gene (NaV), known as kdr mutations, are associated with pyrethroid and DDT insecticide resistance in a number of species. In the mosquito dengue vector Aedes aegypti, besides kdr, other polymorphisms allowed grouping AaNaV sequences as type ‘A’ or ‘B’. Here, we point a series of evidences that these polymorphisms are actually involved in a gene duplication event. Methodology: Four series of methods were employed: (i) genotypying, with allele-specific PCR (AS-PCR), of two AaNaV sites that can harbor kdr mutations (Ile1011Met and Val1016Ile), (ii) cloning and sequencing of part of the AaNaV gene, (iii) crosses with specific lineages and analysis of the offspring genotypes and (iv) copy number variation assays, with TaqMan quantitative real-time PCR. Results: kdr mutations in 1011 and 1016 sites were present only in type ‘A’ sequences, but never in the same haplotype. In addition, although the 1011Met-mutant allele is widely disseminated, no homozygous (1011Met/Met) was detected. Sequencing revealed three distinct haplotypes in some individuals, raising the hypothesis of gene duplication, which was supported by the genotype frequencies in the offspring of specific crosses. Furthermore, it was estimated that a laboratory strain selected for insecticide resistance had 5-fold more copies of the sodium channel gene compared with a susceptible reference strain. Conclusions and implications: The AaNaV duplication here found might be a recent adaptive response to the intense use of insecticides, maintaining together wild-type and mutant alleles in the same organism, conferring resistance and reducing some of its deleterious effects. PMID:24481195

  3. Redeployment of a conserved gene regulatory network during Aedes aegypti development.

    PubMed

    Suryamohan, Kushal; Hanson, Casey; Andrews, Emily; Sinha, Saurabh; Scheel, Molly Duman; Halfon, Marc S

    2016-08-15

    Changes in gene regulatory networks (GRNs) underlie the evolution of morphological novelty and developmental system drift. The fruitfly Drosophila melanogaster and the dengue and Zika vector mosquito Aedes aegypti have substantially similar nervous system morphology. Nevertheless, they show significant divergence in a set of genes co-expressed in the midline of the Drosophila central nervous system, including the master regulator single minded and downstream genes including short gastrulation, Star, and NetrinA. In contrast to Drosophila, we find that midline expression of these genes is either absent or severely diminished in A. aegypti. Instead, they are co-expressed in the lateral nervous system. This suggests that in A. aegypti this "midline GRN" has been redeployed to a new location while lost from its previous site of activity. In order to characterize the relevant GRNs, we employed the SCRMshaw method we previously developed to identify transcriptional cis-regulatory modules in both species. Analysis of these regulatory sequences in transgenic Drosophila suggests that the altered gene expression observed in A. aegypti is the result of trans-dependent redeployment of the GRN, potentially stemming from cis-mediated changes in the expression of sim and other as-yet unidentified regulators. Our results illustrate a novel "repeal, replace, and redeploy" mode of evolution in which a conserved GRN acquires a different function at a new site while its original function is co-opted by a different GRN. This represents a striking example of developmental system drift in which the dramatic shift in gene expression does not result in gross morphological changes, but in more subtle differences in development and function of the late embryonic nervous system. PMID:27341759

  4. Community-based control of Aedes aegypti by adoption of eco-health methods in Chennai City, India

    PubMed Central

    Arunachalam, Natarajan; Tyagi, Brij Kishore; Samuel, Miriam; Krishnamoorthi, R; Manavalan, R; Tewari, Satish Chandra; Ashokkumar, V; Kroeger, Axel; Sommerfeld, Johannes; Petzold, Max

    2012-01-01

    Background Dengue is highly endemic in Chennai city, South India, in spite of continuous vector control efforts. This intervention study was aimed at establishing the efficacy as well as the favouring and limiting factors relating to a community-based environmental intervention package to control the dengue vector Aedes aegypti. Methods A cluster randomized controlled trial was designed to measure the outcome of a new vector control package and process analysis; different data collection tools were used to determine the performance. Ten randomly selected intervention clusters (neighbourhoods with 100 houses each) were paired with ten control clusters on the basis of ecological/entomological indices and sociological parameters collected during baseline studies. In the intervention clusters, Aedes control was carried out using a community-based environmental management approach like provision of water container covers through community actors, clean-up campaigns, and dissemination of dengue information through schoolchildren. The main outcome measure was reduction in pupal indices (pupae per person index), used as a proxy measure of adult vectors, in the intervention clusters compared to the control clusters. Results At baseline, almost half the respondents did not know that dengue is serious but preventable, or that it is transmitted by mosquitoes. The stakeholder analysis showed that dengue vector control is carried out by vertically structured programmes of national, state, and local administrative bodies through fogging and larval control with temephos, without any involvement of community-based organizations, and that vector control efforts were conducted in an isolated and irregular way. The most productive container types for Aedes pupae were cement tanks, drums, and discarded containers. All ten intervention clusters with a total of 1000 houses and 4639 inhabitants received the intervention while the ten control clusters with a total of 1000 houses and 4439

  5. Vector competence of Aedes aegypti and Aedes vittatus (Diptera: Culicidae) from Senegal and Cape Verde archipelago for West African lineages of chikungunya virus.

    PubMed

    Diagne, Cheikh T; Faye, Oumar; Guerbois, Mathilde; Knight, Rachel; Diallo, Diawo; Faye, Ousmane; Ba, Yamar; Dia, Ibrahima; Faye, Ousmane; Weaver, Scott C; Sall, Amadou A; Diallo, Mawlouth

    2014-09-01

    To assess the risk of emergence of chikungunya virus (CHIKV) in West Africa, vector competence of wild-type, urban, and non-urban Aedes aegypti and Ae. vittatus from Senegal and Cape Verde for CHIKV was investigated. Mosquitoes were fed orally with CHIKV isolates from mosquitoes (ArD30237), bats (CS13-288), and humans (HD180738). After 5, 10, and 15 days of incubation following an infectious blood meal, presence of CHIKV RNA was determined in bodies, legs/wings, and saliva using real-time reverse transcription-polymerase chain reaction. Aedes vittatus showed high susceptibility (50-100%) and early dissemination and transmission of all CHIKV strains tested. Aedes aegypti exhibited infection rates ranging from 0% to 50%. Aedes aegypti from Cape Verde and Kedougou, but not those from Dakar, showed the potential to transmit CHIKV in saliva. Analysis of biology and competence showed relatively high infective survival rates for Ae. vittatus and Ae. aegypti from Cape Verde, suggesting their efficient vector capacity in West Africa. PMID:25002293

  6. The effect of Piper aduncum Linn. (Family: Piperaceae) essential oil as aerosol spray against Aedes aegypti (L.) and Aedes albopictus Skuse.

    PubMed

    Misni, Norashiqin; Othman, Hidayatulfathi; Sulaiman, Sallehudin

    2011-08-01

    The bioefficacy of Piper aduncum L. essential oil formulated in aerosol cans was evaluated against Aedes aegypti and Aedes albopictus in a simulated room. The aerosol spray test was based on the Malaysian test standard for aerosol (MS 1221:1991UDC 632.982.2 modified from WHO 2009 methodology) and examined the knockdown effect within 20 minutes of exposure. Mortality rate after 24 hour of holding period was also determined. A commercial aerosol spray (0.09% prallethrin 0.05% d-phenothrin) was also tested as a comparison. Our results showed that the knockdown effect of the commercial aerosol spray and P. aduncum essential oil spray (8% and 10% concentrations) was significantly higher in Ae. albopictus adult females, when compared with that of Ae. aegypti adult females (P<0.05). There was a significant difference in knockdown between commercial aerosol spray and essential oil spray for both Aedes spp. (P<0.05). The essential oil induced significantly higher mortality in Ae. aegypti (80%) than in Ae. albopictus (71.6%) (P<0.05). The commercial aerosol spray caused 97.7% and 86.5% mortality against Ae. aegypti and Ae. albopictus respectively (P<0.05). Based on these data, P. aduncum essential oil has the potential to be used as an aerosol spray against Aedes spp. PMID:22041743

  7. Study on the flying height of Aedes caspius and Culex pipiens females in the Po Delta area, Italy.

    PubMed

    Bellini, R; Veronesi, R; Draghetti, S; Carrieri, M

    1997-12-01

    We have studied the vertical distribution of Culicidae in the "Ancona di Bellocchio" protected area (Regional Park of the Po Delta, Emilia-Romagna, Italy) by means of nonilluminated CDC traps baited with CO2. Traps were placed at heights of 1.5, 3, 4, and 5 m from the ground in open areas and at 1.5, 3, 4, 5, 6, and 7 m in wooded areas. We calculated the average flying height of the species caught, i.e., in order of decreasing flying height, Culex pipiens Linnaeus s.l., Culex modestus Ficalbi, Coquillettidia richiardii (Ficalbi), Aedes detritus (Haliday), Aedes caspius (Pallas). We also calculated the linear regression lines for both sites and found that 90% of Ae. caspius flew within a height of 1.64 m from the ground level, 95% within 2.68 m, and 99% at a height not exceeding 4 m; whereas 90% of Cx. pipiens moved within 3.45 m from the ground level, 95% within 4.02 m, and 99% within 4.76 m. The vertical distributions of Ae. caspius and Cx. pipiens did not vary significantly over the seasons and were not affected by the presence of trees or variations in temperature and wind velocity within the range of measurements obtained. The data obtained provide useful information for planning Ae. caspius control measures based on a mechanical barrier capable of preventing mosquitoes from moving toward residential settlements and tourist resorts bordering on the protected area as an alternative to aerial treatment with the larvicide Bacillus thuringiensis subsp. israelensis. PMID:9474562

  8. Transcriptome Profiling and Genetic Study Reveal Amplified Carboxylesterase Genes Implicated in Temephos Resistance, in the Asian Tiger Mosquito Aedes albopictus

    PubMed Central

    Grigoraki, Linda; Lagnel, Jacques; Kioulos, Ilias; Kampouraki, Anastasia; Morou, Evangelia; Labbé, Pierrick; Weill, Mylene; Vontas, John

    2015-01-01

    Background The control of Aedes albopictus, a major vector for viral diseases, such as dengue fever and chikungunya, has been largely reliant on the use of the larvicide temephos for many decades. This insecticide remains a primary control tool for several countries and it is a potential reliable reserve, for emergency epidemics or new invasion cases, in regions such as Europe which have banned its use. Resistance to temephos has been detected in some regions, but the mechanism responsible for the trait has not been investigated. Principal findings Temephos resistance was identified in an Aedes albopictus population isolated from Greece, and subsequently selected in the laboratory for a few generations. Biochemical assays suggested the association of elevated carboxylesterases (CCE), but not target site resistance (altered AChE), with this phenotype. Illumina transcriptomic analysis revealed the up-regulation of three transcripts encoding CCE genes in the temephos resistant strain. CCEae3a and CCEae6a showed the most striking up-regulation (27- and 12-folds respectively, compared to the reference susceptible strain); these genes have been previously shown to be involved in temephos resistance also in Ae. aegypti. Gene amplification was associated with elevated transcription levels of both CCEae6a and CCEae3a genes. Genetic crosses confirmed the genetic link between CCEae6a and CCEae3a amplification and temephos resistance, by demonstrating a strong association between survival to temephos exposure and gene copy numbers in the F2 generation. Other transcripts, encoding cytochrome P450s, UDP-glycosyltransferases (UGTs), cuticle and lipid biosynthesis proteins, were upregulated in resistant mosquitoes, indicating that the co-evolution of multiple mechanisms might contribute to resistance. Significance The identification of specific genes associated with insecticide resistance in Ae. albopictus for the first time is an important pre-requirement for insecticide

  9. Breeding habitat associations and predicted distribution of an obligate tundra-breeding bird, Smith's Longspur

    USGS Publications Warehouse

    Wild, Teri C.; Kendall, Steven J.; Guldager, Nikki; Powell, Abby N.

    2015-01-01

    Smith's Longspur (Calcarius pictus) is a species of conservation concern which breeds in Arctic habitats that are expected to be especially vulnerable to climate change. We used bird presence and habitat data from point-transect surveys conducted at 12 sites across the Brooks Range, Alaska, 2003–2009, to identify breeding areas, describe local habitat associations, and identify suitable habitat using a predictive model of Smith's Longspur distribution. Smith's Longspurs were observed at seven sites, where they were associated with a variety of sedge–shrub habitats composed primarily of mosses, sedges, tussocks, and dwarf shrubs; erect shrubs were common but sparse. Nonmetric multidimensional scaling ordination of ground cover revealed positive associations of Smith's Longspur presence with sedges and mosses and a negative association with high cover of shrubs. To model predicted distribution, we used boosted regression trees to relate landscape variables to occurrence. Our model predicted that Smith's Longspurs may occur in valleys and foothills of the northeastern and southeastern mountains and in upland plateaus of the western mountains, and farther west than currently documented, over a predicted area no larger than 15% of the Brooks Range. With climate change, shrubs are expected to grow larger and denser, while soil moisture and moss cover are predicted to decrease. These changes may reduce Smith's Longspur habitat quality and limit distribution in the Brooks Range to poorly drained lowlands and alpine plateaus where sedge–shrub tundra is likely to persist. Conversely, northward advance of shrubs into sedge tundra may create suitable habitat, thus supporting a northward longspur distribution shift.

  10. Geographic information system in malaria surveillance: mosquito breeding and imported cases in Israel, 1992.

    PubMed

    Kitron, U; Pener, H; Costin, C; Orshan, L; Greenberg, Z; Shalom, U

    1994-05-01

    Although a significant resurgence of malaria in Israel is unlikely at present, the risk for a localized outbreak of malaria cases due to infection of local anopheline mosquitoes by imported cases does exist. A national computerized surveillance system of breeding sites of Anopheles mosquitoes and imported malaria cases was established in 1992 using a geographic information system (GIS). Distances between population centers and breeding sites were calculated, and maps associating epidemiologic and entomologic data were generated. Risk of malaria transmission was assessed with consideration of vectorial capacity and flight range of each Anopheles species. The GIS-based surveillance system ensures that if a localized outbreak does occur, it will be associated rapidly with a likely breeding site, a specific Anopheles vector, and a probable human source, so that prompt control measures can be most efficiently targeted. This cost-effective GIS-based surveillance system can be expanded and adapted for countries with indigenous malaria transmission. PMID:8203702

  11. Genome-Wide Analysis of Positively Selected Genes in Seasonal and Non-Seasonal Breeding Species

    PubMed Central

    Liu, Mingyu; Chen, Junhui; Tian, Shuai; Zhuo, Min; Zhang, Yu; Zhong, Yang; Du, Hongli; Wang, Xiaoning

    2015-01-01

    Some mammals breed throughout the year, while others breed only at certain times of year. These differences in reproductive behavior can be explained by evolution. We identified positively-selected genes in two sets of species with different degrees of relatedness including seasonal and non-seasonal breeding species, using branch-site models. After stringent filtering by sum of pairs scoring, we revealed that more genes underwent positive selection in seasonal compared with non-seasonal breeding species. Positively-selected genes were verified by cDNA mapping of the positive sites with the corresponding cDNA sequences. The design of the evolutionary analysis can effectively lower the false-positive rate and thus identify valid positive genes. Validated, positively-selected genes, including CGA, DNAH1, INVS, and CD151, were related to reproductive behaviors such as spermatogenesis and cell proliferation in non-seasonal breeding species. Genes in seasonal breeding species, including THRAP3, TH1L, and CMTM6, may be related to the evolution of sperm and the circadian rhythm system. Identification of these positively-selected genes might help to identify the molecular mechanisms underlying seasonal and non-seasonal reproductive behaviors. PMID:26000771

  12. Wetland selection by breeding and foraging black terns in the Prairie Pothole Region of the United States

    USGS Publications Warehouse

    Steen, Valerie A.; Powell, Abby N.

    2012-01-01

    We examined wetland selection by the Black Tern (Chlidonias niger), a species that breeds primarily in the prairie pothole region, has experienced population declines, and is difficult to manage because of low site fidelity. To characterize its selection of wetlands in this region, we surveyed 589 wetlands throughout North and South Dakota. We documented breeding at 5% and foraging at 17% of wetlands. We created predictive habitat models with a machine-learning algorithm, Random Forests, to explore the relative role of local wetland characteristics and those of the surrounding landscape and to evaluate which characteristics were important to predicting breeding versus foraging. We also examined area-dependent wetland selection while addressing the passive sampling bias by replacing occurrence of terns in the models with an index of density. Local wetland variables were more important than landscape variables in predictions of occurrence of breeding and foraging. Wetland size was more important to prediction of foraging than of breeding locations, while floating matted vegetation was more important to prediction of breeding than of foraging locations. The amount of seasonal wetland in the landscape was the only landscape variable important to prediction of both foraging and breeding. Models based on a density index indicated that wetland selection by foraging terns may be more area dependent than that by breeding terns. Our study provides some of the first evidence for differential breeding and foraging wetland selection by Black Terns and for a more limited role of landscape effects and area sensitivity than has been previously shown.

  13. Agriculture modifies the seasonal decline of breeding success in a tropical wild bird population

    PubMed Central

    Cartwright, Samantha J; Nicoll, Malcolm A C; Jones, Carl G; Tatayah, Vikash; Norris, Ken

    2014-01-01

    Habitat conversion for agriculture is a major driver of biodiversity loss, but our understanding of the demographic processes involved remains poor. We typically investigate the impacts of agriculture in isolation even though populations are likely to experience multiple, concurrent changes in the environment (e.g. land and climate change). Drivers of environmental change may interact to affect demography, but the mechanisms have yet to be explored fully in wild populations. Here, we investigate the mechanisms linking agricultural land use with breeding success using long-term data for the formerly Critically Endangered Mauritius kestrel Falco punctatus, a tropical forest specialist that also occupies agricultural habitats. We specifically focused on the relationship between breeding success, agriculture and the timing of breeding because the latter is sensitive to changes in climatic conditions (spring rainfall) and enables us to explore the interactive effects of different (land and climate) drivers of environmental change. Breeding success, measured as egg survival to fledging, declines seasonally in this population, but we found that the rate of this decline became increasingly rapid as the area of agriculture around a nest site increased. If the relationship between breeding success and agriculture was used in isolation to estimate the demographic impact of agriculture, it would significantly under-estimate breeding success in dry (early) springs and over-estimate breeding success in wet (late) springs. Analysis of prey delivered to nests suggests that the relationship between breeding success and agriculture might be due, in part, to spatial variation in the availability of native, arboreal geckos. Synthesis and applications. Agriculture modifies the seasonal decline in breeding success in this population. As springs are becoming wetter in our study area and since the kestrels breed later in wetter springs, the impact of agriculture on breeding success will

  14. USVL-220, A Novel Watermelon Breeding Line

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel watermelon breeding line was developed at the USDA, ARS, U.S. Vegetable Laboratory, Charleston, South Carolina. This breeding line contains the nuclear genome of cultivated watermelon (Citrullus lanatus var. lanatus) and the chloroplast and mitochondrial genomic background of the desert spe...

  15. What breeds make up the national herd?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in the procedures and database at the Animal Improvement Programs Laboratory have resulted in the ability to know which breeds contribute to each cow and in what proportion. Previously each animal was considered to be the single breed reported through the dairy industry; therefore, statistic...

  16. Grasses and Legumes: Genetics and Plant Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Humans have been breeding forage and turf species for over 100 years. This chapter explores the progress that has been made in improving grasses and legumes for human benefit and the evolution of breeding and selection systems that have brought about those changes....

  17. Breeding sugarcane for temperate and cold environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Louisiana represents one of the world’s more temperate environments where sugarcane is commercially grown. Since its inception in the 1920s, The USDA-ARS breeding program at the Sugarcane Research Laboratory in Houma, Louisiana, U.S.A. has focused on breeding varieties adapted to this unique envir...

  18. Mean EPDs reported by different breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef cattle genetic evaluations result in expected progeny differences (EPDs), which can be used to select animals for growth, productivity, carcass composition, and, most recently, economic value. Breed averages allow producers to compare the genetic value of potential breed stock against their br...

  19. Mean EPDs Reported by Different Breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef cattle genetic evaluations result in expected progeny differences (EPDs), which can be used to select animals for growth, productivity, carcass composition, and, most recently, economic value. Breed averages allow producers to compare the genetic value of potential breeding stock against their...

  20. Breeding Perspectives and Programs at East Lansing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    USDA-ARS sugar beet breeding activities for both Aphanomyces resistance and CMS/O-type conversion at East Lansing reach back to the 1940’s, with variety testing activities at Michigan State University reaching back to circa 1911. Many of those contributions are well known in the sugar beet breeding ...

  1. Plant Breeding: Surprisingly, Less Sex Is Better.

    PubMed

    van Dijk, Peter J; Rigola, Diana; Schauer, Stephen E

    2016-02-01

    Introduction of apomixis, asexual reproduction through seeds, into crop species has the potential to dramatically transform plant breeding. A new study demonstrates that traits can be stably transferred between generations in newly produced apomictic lines, and heralds a breeding revolution needed to increase food production for the growing planet. PMID:26859270

  2. Mean EPDs Reported by Different Breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef cattle genetic evaluations result in expected progeny differences (EPDs), which can be used to select animals for growth, productivity, carcass composition, and, most recently, economic value. Breed averages allow producers to compare the genetic value of potential breed stock against their br...

  3. Breeding commercial sugarcane varieties for the industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent literature suggests that sugarcane breeding in the United States has reached a sugar yield plateau. If so, this could have huge implications for the future of the industry and breeding per se because yield improvement might have to be achieved through secondary, non-sugar-related traits, or t...

  4. Mean EPDs reported by different breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef cattle genetic evaluations result in expected progeny differences (EPDs), which can be used to select animals for growth, productivity, carcass composition, and, most recently, economic value. Breed averages allow producers to compare the genetic value of potential breeding stock against their...

  5. Breeding potato at the diploid level

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In most regions of the world, potato cultivars are tetraploid. However, complexities due to tetraploid genetics have slowed breeding progress and limited the implementation of breeding strategies commonly used in other major crops. We are developing diploid genetics resources, including partially in...

  6. Mean EPDs reported by different breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef cattle genetic evaluations result in expected progeny differences (EPDs), which can be used to select animals for growth, productivity, carcass composition, and, most recently, economic value. Breed averages allow producers to compare the genetic value of potential breeding stock against their ...

  7. Genetic Evaluations for Mixed-Breed Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An all-breed animal model was developed for routine genetic evaluations of US dairy cattle. Data sets from individual breeds were combined, and records from crossbred cows were included. About 1% of recent cows were first generation crossbreds. Numbers of cows with records since 1960 ranged from 10 ...

  8. Sugarcane Improvement Through Breeding and Biotechnology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The advancements in sugarcane breeding and the improvement of sugarcane through biotechnology have been reviewed by a team of leading sugarcane specialists from around the world. Topics covered in the breeding section include the evolution and origin of sugarcane, early history of conventional sugar...

  9. Breeding broccoli adapted to high temperature environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A breeding program to select broccoli (Brassica oleracea L. Italica Group) for adaptation to summer environments has been conducted at the U.S. Vegetable Laboratory (USVL) in Charleston, South Carolina, for almost two decades. This effort provides a case study of a concerted effort to breed polygen...

  10. Aedes albopictus and Its Environmental Limits in Europe.

    PubMed

    Cunze, Sarah; Kochmann, Judith; Koch, Lisa K; Klimpel, Sven

    2016-01-01

    The Asian tiger mosquito Aedes albopictus, native to South East Asia, is listed as one of the worst invasive vector species worldwide. In Europe the species is currently restricted to Southern Europe, but due to the ongoing climate change, Ae. albopictus is expected to expand its potential range further northwards. In addition to modelling the habitat suitability for Ae. albopictus under current and future climatic conditions in Europe by means of the maximum entropy approach, we here focused on the drivers of the habitat suitability prediction. We explored the most limiting factors for Aedes albopictus in Europe under current and future climatic conditions, a method which has been neglected in species distribution modelling so far. Ae. albopictus is one of the best-studied mosquito species, which allowed us to evaluate the applied Maxent approach for most limiting factor mapping. We identified three key limiting factors for Ae. albopictus in Europe under current climatic conditions: winter temperature in Eastern Europe, summer temperature in Southern Europe. Model findings were in good accordance with commonly known establishment thresholds in Europe based on climate chamber experiments and derived from the geographical distribution of the species. Under future climatic conditions low winter temperature were modelled to remain the most limiting factor in Eastern Europe, whereas in Central Europe annual mean temperature and summer temperatures were modelled to be replaced by summer precipitation, respectively, as most limiting factors. Changes in the climatic conditions in terms of the identified key limiting factors will be of great relevance regarding the invasive potential of the Ae. albopictus. Thus, our results may help to understand the key drivers of the suggested range expansion under climate change and may help to improve monitoring programmes. The applied approach of investigating limiting factors has proven to yield valuable results and may also provide

  11. Winter Refuge for Aedes aegypti and Ae. albopictus Mosquitoes in Hanoi during Winter

    PubMed Central

    Tsunoda, Takashi; Cuong, Tran Chi; Dong, Tran Duc; Yen, Nguyen Thi; Le, Nguyen Hoang; Phong, Tran Vu; Minakawa, Noboru

    2014-01-01

    Dengue occurs throughout the year in Hanoi, Vietnam, despite winter low temperatures <10°C. During July 2010 to March 2012, we surveyed monthly for Aedes larvae and pupae in 120 houses in 8 Hanoi districts. Aedes albopictus preferred discarded containers in summer and pupal density drastically decreased in winter. Aedes aegypti preferred concrete tanks and this preference increased in winter. Even in winter, the lowest water temperature found in concrete tanks was >14°C, exceeding the developmental zero point of Ae. aegypti. Although jars, drums and concrete tanks were the dominant containers previously (1994–97) in Hanoi, currently the percentage of residences with concrete tanks was still high while jars and drums were quite low. Our study showed that concrete tanks with broken lids allowing mosquitoes access were important winter refuge for Ae. aegypti. We also indicate a concern about concrete tanks serving as foci for Ae. aegypti to expand their distribution in cooler regions. PMID:24752230

  12. Innate Cellular Immune Responses in Aedes caspius (Diptera: Culicidae) Mosquitoes.

    PubMed

    Soliman, D E; Farid, H A; Hammad, R E; Gad, A M; Bartholomay, L C

    2016-03-01

    Mosquitoes transmit a variety of pathogens that have devastating consequences for global public and veterinary health. Despite their capacity to serve as vectors, these insects have a robust capacity to respond to invading organisms with strong cellular and humoral immune responses. In Egypt, Aedes caspius (Pallas, 1771) has been suspected to act as a bridge vector of Rift Valley Fever virus between animals and humans. Microscopic analysis of Ae. caspius hemolymph revealed the presence of phagocytic cells called granulocytes. We further evaluated cellular immune responses produced by Ae. caspius as a result of exposure to a Gram-negative, and Gram-positive bacterium, and to latex beads. After challenge, a rapid and strong phagocytic response against either a natural or synthetic invader was evident. Hemocyte integrity in bacteria-inoculated mosquitoes was not morphologically affected. The number of circulating granulocytes decreased with age, reducing the overall phagocytic capacity of mosquitoes over time. The magnitude and speed of the phagocytic response suggested that granulocytes act as an important force in the battle against foreign invaders, as has been characterized in other important mosquito vector species. PMID:26792848

  13. Intriguing olfactory proteins from the yellow fever mosquito, Aedes aegypti

    NASA Astrophysics Data System (ADS)

    Ishida, Yuko; Chen, Angela M.; Tsuruda, Jennifer M.; Cornel, Anthon J.; Debboun, Mustapha; Leal, Walter S.

    2004-09-01

    Four antennae-specific proteins (AaegOBP1, AaegOBP2, AaegOBP3, and AaegASP1) were isolated from the yellow fever mosquito, Aedes aegypti and their full-length cDNAs were cloned. RT-PCR indicated that they are expressed in female and, to a lesser extent, in male antennae, but not in control tissues (legs). AaegOBP1 and AaegOBP3 showed significant similarity to previously identified mosquito odorant-binding proteins (OBPs) in cysteine spacing pattern and sequence. Two of the isolated proteins have a total of eight cysteine residues. The similarity of the spacing pattern of the cysteine residues and amino acid sequence to those of previously identified olfactory proteins suggests that one of the cysteine-rich proteins (AaegOBP2) is an OBP. The other (AaegASP1) did not belong to any group of known OBPs. Structural analyses indicate that six of the cysteine residues in AaegOBP2 are linked in a similar pattern to the previously known cysteine pairing in OBPs, i.e., Cys-24 Cys-55, Cys-51 Cys-104, Cys-95 Cys-113. The additional disulfide bridge, Cys-38 Cys-125, knits the extended C-terminal segment of the protein to a predicted α2-helix. As indicated by circular dichroism (CD) spectra, the extra rigidity seems to prevent the predicted formation of a C-terminal α-helix at low pH.

  14. Functional Development of the Octenol Response in Aedes aegypti

    PubMed Central

    Bohbot, Jonathan D.; Durand, Nicolas F.; Vinyard, Bryan T.; Dickens, Joseph C.

    2013-01-01

    Attraction of female Aedes aegypti mosquitoes to 1-octen-3-ol (octenol), CO2, lactic acid, or ammonia emitted by vertebrate hosts is not only contingent on the presence of odorants in the environment, but is also influenced by the insect’s physiological state. For anautogenous mosquito species, like A. aegypti, newly emerged adult females neither respond to host odors nor engage in blood-feeding; the bases for these behaviors are poorly understood. Here we investigated detection of two components of an attractant blend emitted by vertebrate hosts, octenol, and CO2, by female A. aegypti mosquitoes using electrophysiological, behavioral, and molecular approaches. An increase in sensitivity of octenol olfactory receptor neurons (ORNs) was correlated with an increase in odorant receptor gene (Or) expression and octenol-mediated attractive behavior from day 1 to day 6 post-emergence. While the sensitivity of octenol ORNs was maintained through day 10, behavioral responses to octenol decreased as did the ability of females to discriminate between octenol and octenol + CO2. Our results show differing age-related roles for the peripheral receptors for octenol and higher order neural processing in the behavior of female mosquitoes. PMID:23471139

  15. Macroclimate determines the global range limit of Aedes aegypti.

    PubMed

    Capinha, César; Rocha, Jorge; Sousa, Carla A

    2014-09-01

    Aedes aegypti is the main vector of dengue and a number of other diseases worldwide. Because of the domestic nature of this mosquito, the relative importance of macroclimate in shaping its distribution has been a controversial issue. We have captured here the worldwide macroclimatic conditions occupied by A. aegypti in the last century. We assessed the ability of this information to predict the species' observed distribution using supra-continental spatially-uncorrelated data. We further projected the distribution of the colonized climates in the near future (2010-2039) under two climate-change scenarios. Our results indicate that the macroclimate is largely responsible for setting the maximum range limit of A. aegypti worldwide and that in the near future, relatively wide areas beyond this limit will receive macroclimates previously occupied by the species. By comparing our projections, with those from a previous model based strictly on species-climate relationships (i.e., excluding human influence), we also found support for the hypothesis that much of the species' range in temperate and subtropical regions is being sustained by artificial environments. Altogether, these findings suggest that, if the domestic environments commonly exploited by this species are available in the newly suitable areas, its distribution may expand considerably in the near future. PMID:24643859

  16. Oxime derivatives with larvicidal activity against Aedes aegypti L.

    PubMed

    Lima, Tamires Cardoso; Santos, Sandra Regina Lima; Uliana, Marciana P; Santos, Roseli La Corte; Brocksom, Timothy John; Cavalcanti, Sócrates Cabral de Holanda; de Sousa, Damião Pergentino

    2015-08-01

    Oximes containing secondary metabolites constitute an important group of bioactive compounds and have been described and frequently updated in the literature due to their pharmacological properties. Thus, the aim of this study was to evaluate the larvicidal activity of a series of fourteen structurally related [1,4]-Benzoquinone mono-oximes on third-instar Aedes aegypti larvae and to investigate structure-activity relationships (SAR) of these compounds. Results of larvicidal assay revealed that all oximes were found to have larvicidal activity. Compound 2,6-dimethyl-[1,4]-benzoquinone oxime tosylate (11) was the most bioactive (LC50 = 9.858 ppm), followed by 2-methyl-[1,4]-benzoquinone oxime tosylate (9) (LC50 = 14.450 ppm). [1,4]-benzoquinone oxime (1) exhibited the lowest potency, with an LC50 = 121.181 ppm. The molecular characteristics which may help to understand the assayed compounds larvicidal activity were identified. SAR indicates that the addition of alkyl groups attached to the ring, number, position in the unsaturated cyclic structure, and size of these groups influence the larvicidal activity. Moreover, the lipophilicity seems to play an important role in increasing the larvicidal effect, because, in general, tosyl-containing products were more potent than products containing free OH. PMID:25956398

  17. Formulas of components of citronella oil against mosquitoes (Aedes aegypti).

    PubMed

    Hsu, Wey-Shin; Yen, Jui-Hung; Wang, Yei-Shung

    2013-01-01

    The mosquito Aedes aegypti is an epidemic vector of several diseases such as dengue fever and yellow fever. Several pesticides are used to control the mosquito population. Because of their frequent use, some mosquitoes have developed resistance. In this study, we used the Y-tube olfactometer to test essential oils of Cymbopogon species and screened specific formulas of components as repellents against Ae. aegypti. At 400 μL, the extracted oil of citronella grass (Cymbopogon nardus) and myrcene produced a low-active response by inhibiting mosquito host-seeking activity. Citronella grass, lemon grass (Cymbopogon citratus), citral and myrcene also produced a low-treatment response to repellents, for more potential to affect host-seeking behavior. Furthermore, the mixture of citral, myrcene, and citronellal oil (C:M:Ci = 6:4:1) greatly affected and inhibited host-seeking behavior (76% active response; 26% treatment response with 40 μL; 42.5%, 18% with 400 μL; and 19%, 23% with 1000 μL). As compared with the result for N,N-diethyl-3-methylbenzamide (DEET; 44%, 22% with 400 μL), adjusting the composition formulas of citronella oil had a synergistic effect, for more effective repellent against Ae. aegypti. PMID:23998314

  18. Distribution and dynamics of Wolbachia infection in Malaysian Aedes albopictus.

    PubMed

    Joanne, Sylvia; Vythilingam, Indra; Yugavathy, Nava; Leong, Cherng-Shii; Wong, Meng-Li; AbuBakar, Sazaly

    2015-08-01

    Wolbachia are maternally transmitted bacteria found in most arthropods and nematodes, but little is known about their distribution and reproductive dynamics in the Malaysian dengue vector Aedes albopictus. In this study, polymerase chain reaction (PCR) was used to determine the presence of Wolbachia from field collected Ae. albopictus from various parts of the country using wsp specific primers. Ae. albopictus had Wolbachia infection ranging from 60 to 100%. No sequence diversity of wsp gene was found within all wAlbA and wAlbB sequences. Our findings suggest that Wolbachia infection amongst the Malaysian Ae. albopictus were not homogenously distributed in all districts in Malaysia. The presence of Wolbachia in different organs of Ae. albopictus was also determined. Wolbachia were only found in the ovaries and midguts of the mosquitoes, while absent in the salivary glands. The effects of Wolbachia on Ae. albopictus fecundity, longevity and egg viability were studied using infected and uninfected colonies. The removal of Wolbachia from Ae. albopictus resulted in reduced fecundity, longevity and egg viability, thus. Wolbachia seem to play a vital role in Ae. albopictus reproductive system. PMID:25899523

  19. New Candidates for Plant-Based Repellents Against Aedes aegypti.

    PubMed

    Misni, Norashiqin; Nor, Zurainee Mohamed; Ahmad, Rohani

    2016-06-01

    Based on an ethnobotanical study on use for plant species against mosquito bites in the Kota Tinggi District, Johor State, Malaysia, 3 plants selected for study, Citrus aurantifolia (leaves), Citrus grandis (fruit peel), and Alpinia galanga (rhizome), were extracted using hydrodistillation to produce essential oils. These essential oils were then formulated as a lotion using a microencapsulation process and then tested for their repellent effect against Aedes aegypti. N,N-diethyl-m-toluamide (deet) was also prepared in the same formulation and tested for repellency as controls. Four commercial plant-based repellent (KAPS(®), MozAway(®), BioZ Natural(®), and Mosiquard(®)) also were incorporated in the bioassay for comparison purposes. Bioassays revealed that at 20% concentration all repellent formulations demonstrated complete protection for 2 h and >90% for 4 h post-application. The A. galanga-based formulation provided the greatest level of protection (98.91%), which extended for 4 h post-application and was not significantly different from deet at similar concentration. When compared with commercial plant-based repellents (KAPS(®), MozAway(®), and BioZ Natural(®)), the 3 lotion formulations showed significantly better protection against Ae. aegypti bites, providing >90% protection for 4 h. In conclusion, our 3 plant-based lotion formulations provided acceptable levels of protection against host-seeking Ae. aegypti and should be developed. PMID:27280349

  20. Repellent activity of selected essential oils against Aedes aegypti.

    PubMed

    Choochote, W; Chaithong, U; Kamsuk, K; Jitpakdi, A; Tippawangkosol, P; Tuetun, B; Champakaew, D; Pitasawat, B

    2007-07-01

    Essential oils extracted from ten plant species were screened for repellency against Aedes aegypti mosquitoes. Three oils; Zanthoxylum piperitum, Anethum graveolens and Kaempferia galanga, exerted protection against A. aegypti, with median complete-protection times of 1, 0.5 and 0.25 h, respectively. The protection times were increased significantly by incorporating 10% vanillin. The highest potential was established from Z. piperitum oil +10% vanillin (2.5 h, range=1-2.5 h). Mixtures from pairs of the effective oils possessed slight repellency that ranged from 0-0.5 h. None of the oil combinations repelled A. aegypti for longer than their constituent oil alone. With vanillin added, however, each oil mixture provided improved protection, which was approximately equal to oil on its own. GC/MS analysis revealed that the main component of Z. piperitum fruit oil was limonene (37.99%), with minor amounts of sabinene (13.30%) and beta-myrcene (7.17%). Repellent testing of stored samples of Z. piperitum fruit oil against A. aegypti demonstrated that repellent activity of those kept at -20 degrees C or 4 degrees C was present for a period of at least 3 months. Therefore, the essential oil of Z. piperitum fruit may prove useful in the development of mosquito repellents as an effective personal protection measure against mosquito bites. PMID:17512681