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Sample records for boll weevil

  1. Boll weevil invasion process in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The boll weevil, Anthonomus grandis grandis Boheman, is the most destructive cotton pest in the Western Hemisphere. In 1993, the pest was reported in Argentina, and in 1994 boll weevils were captured in cotton fields in the Formosa Province on the border between Argentina and Paraguay. The pest ha...

  2. Three Boll Weevil Diapause Myths in Perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The boll weevil, Anthonmus grandis grandis Boheman (Coleoptera: Curculionidae), originated in Mesoamerica but its contemporary distribution extends from the United States Cotton Belt to Argentina, throughout which it is a serious pest of cotton, Gossypium hirsutum L. While research on the boll weev...

  3. Boll weevil eradication: a model for sea lamprey control?

    USGS Publications Warehouse

    Smith, James W.; Swink, William D.

    2003-01-01

    Invasions of boll weevil (Anthonomus grandis) into the United States and sea lamprey (Petromyzon marinus) into the Great Lakes were similar in many ways. Important species (American cotton, Gossypium hirsutum, and lake trout, Salvelinus namaycush) and the industries they supported were negatively affected. Initial control efforts were unsuccessful until pesticides and application technologies were developed. For boll weevils, controls relying on pesticides evolved into an integrated program that included recommended farming practices and poisoned baits. However, the discovery of a boll weevil sex pheromone in 1964 allowed adoption of an ongoing program of eradication. Despite opposition over concept and cost, insecticides, pheromone traps, poisoned baits, and approved farming practices were used to eradicate boll weevils from Virginia, North Carolina, South Carolina, Georgia, Florida, and Alabama by 1999. Using the working back approach along the path of the original invasion, eradication was nearly completed by 2002 in Mississippi and eradication programs were underway in Arkansas, Tennessee, Oklahoma, Louisiana, and parts of Texas. Insecticide use for cotton production decreased 50 to 90%, and cotton yields and farm income increased an average of 78 kg/ha and $190 U.S./ha in areas where boll weevils were eradicated. For sea lampreys, integrated management uses lampricides, barriers to migration, trapping, and release of sterilized males. Although sea lamprey eradication is not currently feasible, recent research on larval and sex pheromones might provide the tools to make it possible. A successful eradication program for sea lampreys starting in Lake Superior and expanding to the lower Great Lakes would ultimately provide huge ecological and economic benefits by eliminating lampricide applications, removing barriers that block teleost fishes, and facilitating the recovery of lake trout. Should the opportunity arise, the concept of sea lamprey eradication should

  4. Reducing boll weevil populations by clipping terminal buds and removing abscised fruiting bodies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae) punctures cotton squares and young bolls during feeding and oviposition, causing abscission of flower buds (squares) in the instance of oviposition. Fallen squares are a source of next generation adult boll weevils that...

  5. Forensic pollen geolocation techniques used to identify the origin of boll weevil reinfestation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The boll weevil, Anthonomus grandis, entered the United States of America in the early 20th century and became a major pest in cotton, Gossypium spp. Shortly after the passage of Tropical Storm Erin on 16 August 2007 through the South Texas/Winter Garden boll weevil eradication zone, over 150 boll ...

  6. Attraction of dispersing boll weevils from surrounding habitats relative to simulated pheromone diffusion from traps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to detect populations of boll weevils, Anthonomus grandis (Boheman), with pheromone traps has contributed significantly in progress toward eradication of the boll weevil. However, new information is needed to aid in the interpretation of trap captures, such as identification of habitats...

  7. A Model Evaluation of Long-Distance Dispersal of Boll Weevils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boll weevil eradication programs have progressed toward eradication within each zone, but concerns remain about the possibility of weevil dispersal between eradication zones. In this study, the HYSPLIT atmospheric dispersion model was used to simulate daily wind-aided dispersal of weevils from the ...

  8. Relationships of abscised cotton fruit to boll weevil (Coleoptera: Curculionidae) feeding, oviposition, and development.

    PubMed

    Showler, Allan T

    2008-02-01

    Abscised cotton, Gossypium hirsutum L., fruit in field plots planted at different times were examined to assess adult boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), use of squares and bolls during 2002 and 2003 in the Lower Rio Grande Valley of Texas. Although boll abscission is not necessarily related to infestation, generally more bolls abscised than squares and abundances of fallen bolls were not related to the planting date treatments. During 2003, fallen squares were most abundant in the late-planted treatment. Although large squares (5.5-8-mm-diameter) on the plant are preferred for boll weevil oviposition, diameter of abscised squares is not a reliable measurement because of shrinkage resulting from desiccation and larval feeding. Fallen feeding-punctured squares and bolls were most abundant in late plantings but differences between fallen feeding-punctured squares versus fallen feeding-punctured bolls were found in only one treatment in 2003. During the same year, fallen oviposition-punctured squares were more numerous in the late-planted treatment than in the earlier treatments. Treatment effects were not found on numbers of oviposition-punctured bolls, but fallen oviposition-punctured squares were more common than bolls in the late-planted treatment compared with earlier treatments each year. Dead weevil eggs, larvae, and pupae inside fallen fruit were few and planting date treatment effects were not detected. Living third instars and pupae were more abundant in fallen squares of the late-planted treatment than in the earlier treatments and bolls of all three treatments. This study shows that fallen squares in late-planted cotton contribute more to adult boll weevil populations than bolls, or squares of earlier plantings. PMID:18330118

  9. Survival and preference of cotton boll weevil adults for alternative food sources.

    PubMed

    Pimenta, M; Mata, R A; Venzon, M; Cunha, D N C; Fontes, E M G; Pires, C S S; Sujii, E R

    2016-06-01

    Plants that have potential as alternative food source (floral nectar, pollen and plant tissues) to the boll weevil during the intercropping season were evaluated considering the prevalent conditions of Cerrado in the Central Brazil. Initially, we tested the nutritional adequacy for the survival of the insect of flower resource (pollen and nectar) provided by eight plant species (fennel, mexican sunflower, castor bean, okra, hibiscus, sorghum, pigeonpea and sunn hemp). Subsequently, we tested if the resources provided by the selected plants continued to be exploited by the boll weevil in the presence of cotton plant, its main food source average longevity of boll weevil adults was significantly longer when they were fed on hibiscus' flowers (166.6 ± 74.4) and okra flowers (34.7 ± 28.9) than when they fed on flowers of other six species. Subsequently, the preference of the boll weevil in the use of resources was compared between okra or hibiscus and cotton plants, in dual choice experiments. Boll weevils preferred plants of the three species in the reproductive stages than those in vegetative stages. Although the cotton plant in the reproductive stage was the most preferred plant of all, boll weevils preferred flowering okra and hibiscus than cotton at the vegetative stage. PMID:26934148

  10. Boll weevils (Coleoptera: Curculionidae) continue to release pheromone following host removal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pheromone traps are a key component of management and eradication programs directed against the boll weevil, Anthonomus grandis (Boheman), but trap data remain difficult to interpret because of the day-to-day variability in captures. Our prior observations suggested a substantial proportion of boll...

  11. Captures of Boll Weevils (Coleoptera: Curculionidae) in Relation to Trap Orientation and Distance From Brush Lines.

    PubMed

    Spurgeon, Dale W

    2016-04-01

    Eradication programs for the boll weevil (Anthonomus grandis grandis Boheman) rely on pheromone-baited traps to trigger insecticide treatments and monitor program progress. A key objective of monitoring in these programs is the timely detection of incipient weevil populations to limit or prevent re-infestation. Therefore, improvements in the effectiveness of trapping would enhance efforts to achieve and maintain eradication. Association of pheromone traps with woodlots and other prominent vegetation are reported to increase captures of weevils, but the spatial scale over which this effect occurs is unknown. The influences of trap distance (0, 10, and 20 m) and orientation (leeward or windward) to brush lines on boll weevil captures were examined during three noncropping seasons (October to February) in the Rio Grande Valley of Texas. Differences in numbers of captured weevils and in the probability of capture between traps at 10 or 20 m from brush, although often statistically significant, were generally small and variable. Variations in boll weevil population levels, wind directions, and wind speeds apparently contributed to this variability. In contrast, traps closely associated with brush (0 m) generally captured larger numbers of weevils, and offered a higher probability of weevil capture compared with traps away from brush. These increases in the probability of weevil capture were as high as 30%. Such increases in the ability of traps to detect low-level boll weevil populations indicate trap placement with respect to prominent vegetation is an important consideration in maximizing the effectiveness of trap-based monitoring for the boll weevil. PMID:26719592

  12. Captures of boll weevils (Coleoptera: Curculionidae) in relation to trap distance from cotton fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Once populations of the boll weevil (Anthonomus grandis grandis Boheman) are suppressed, eradication programs rely on pheromone trap-based monitoring for timely detection of weevil populations in cotton (Gossypium spp.). Delayed detection may increase the costs of remedial treatments, and permit rep...

  13. Susceptibility of the boll weevil to Steinernema riobrave and other entomopathogenic nematodes.

    PubMed

    Enrique Cabanillas, H

    2003-03-01

    The susceptibility of the boll weevil (BW), Anthonomus grandis Boheman, to Steinernema riobrave and other nematode species in petri dishes, soil (Hidalgo sandy clay loam), and cotton bolls and squares was investigated. Third instar weevils were susceptible to entomopathogenic nematode (EN) species and strains in petri dish bioassays at 30 degrees C. Lower LC(50)'s occurred with S. riobrave TX- 355 (2 nematodes per weevil), S. glaseri NC (3), Heterorhabditis indicus HOM-1 (5), and H. bacteriophora HbL (7) than H. bacteriophora IN (13), S. riobrave TX (14), and H. bacteriophora HP88 (21). When infective juveniles (IJs) of S. riobrave were applied to weevils on filter paper at 25 degrees C, the LC(50) of S. riobrave TX for first, second, and third instars, pupae, and 1-day-old and 10-days-old adult weevils were 4, 5, 4, 12, 13, and 11IJs per weevil, respectively. The mean time to death, from lowest to highest concentration, for the first instar (2.07 and 1.27days) and second instar (2.55 and 1.39days) weevils were faster than older weevil stages. But, at concentrations of 50 and 100IJs/weevil, the mean time to death for the third instar, pupa and adult weevils were similar (1.84 and 2.67days). One hundred percent weevil mortality (all weevil stages) occurred 3days after exposure to 100IJs per weevil. Invasion efficiency rankings for nematode concentration were inconsistent and changed with weevil stage from 15 to 100% when weevils were exposed to 100 and 1IJs/weevil, respectively. However, there was a consistent relationship between male:female nematode sex ratio (1:1.6) and nematode concentration in all infected weevil stages. Nematode production per weevil cadaver increased with increased nematode concentrations. The overall mean yield of nematodes per weevil was 7680IJs. In potted soil experiments (30 degrees C), nematode concentration and soil moisture greatly influenced the nematode efficacy. At the most effective concentrations of 200,000 and 400,000IJs/m(2) in

  14. Mass propagation of the boll weevil parasite, Catolaccus grandis

    SciTech Connect

    Palamara, K.J.

    1995-01-01

    The USDA and the DOE production facility at Kansas City managed by AlliedSignal have partnered to redirect defense technologies to the development of specialized agricultural equipment. The initial use of the equipment will be for mass rearing of the boll weevil parasite, Catolaccus grandis, however, by reprogramming and altering fixtures, the equipment can be used for other insect species. The process flow diagrams for the following systems have been developed: (1) Mechanized Host Larvae Washing/Drying, Capsule Forming, Larvae Placement, Sealing, and Labeling; (2) Mechanized in vivo Preoviposition, Oviposition, and Developing; (3) Mechanized Placement in Release Containers; (4) Automated Packaging and Storage/Retrieval; (5) Mechanized System for Field Release; (6) Mechanized System for Adult Colony Maintenance, Egg Laying, and Egg Retrieval; (7) Mechanized System for in vitro Diet Manufacturing; (8) Mechanized System for in vitro Mass Propagation with Diet Dispensing, Egg Placement, and Developing of Parasite Pupae. Conceptual designs using ProEngineer software have been developed for four of the eight systems. The initial hardware will include the elements of the systems considered to be the most technologically challenging and those necessary to establish the feasibility of commercial mass rearing. The most important of these are mechanized in vitro diet manufacturing, egg laying/retrieval, egg placement and diet dispensing.

  15. Early-season colonization patterns of the boll weevil (Coleoptera: Curculionidae) in Central Texas cotton.

    PubMed

    Reardon, B J; Spurgeon, D W

    2003-04-01

    It is commonly believed that colonization of early-season cotton, Gossypium hirsutum L., by overwintered boll weevils, Anthonomus grandis grandis Boheman, is concentrated on field margins. However, supporting experimental evidence is not available. In 1999 and 2000, we examined colonization patterns of overwintered boll weevils in Central Texas cotton on the bases of adult collections by a pneumatic sampler and hand collections of abscised infested squares. Samples were taken from sites arranged in a grid that extended inward >70 m from the field margin. Adults were collected from shortly after seedling emergence until the flowering stage, and infested squares were collected during the one-third grown square stage. Despite numerical trends, the numbers of adult weevils collected were not significantly different between years or sexes, or among plant phenological stages. Field-to-field variation among collections was considerable and likely prevented detection of differences among these factors. Spatial patterns represented by adult weevil and infested square collections were examined by logistic regressions fitted to the respective probabilities of weevil detection at each designated sample site. Although we observed trends for slightly decreased probability of weevil detection with increased distance from the field margin, these trends were too weak to be demonstrated statistically. Our results indicate the boll weevil does not consistently exhibit a strong edge-oriented colonization pattern, and that management tactics that are predicated on these patterns, such as border sprays, should be used with caution.

  16. "The herald of prosperity": tracing the boll weevil myth in Alabama.

    PubMed

    Giesen, James C

    2011-01-01

    As scholars and singers have pointed out in monographs and folk songs, the cotton boll weevil was a devastating force on southern farming and rural life. No symbol is more indicative of this destruction than Enterprise, Alabama's boll weevil monument. This essay examines not how the cotton pest destroyed the region's staple crop, but how women and men across race and class lines understood the beetle's threat and used it to their advantage. The statue, like the countless blues and folk songs about the pest, was a cultural statement that shaped the understanding of the bug itself and its supposed transformation of southern agriculture. By examining the local conditions that gave rise to dramatic, albeit short-lived, crop diversification, and in turn the monument's erection, this essay uncovers the ways in which the boll weevil myth was as important a force on southern life as the long-snouted beetle itself. PMID:21313785

  17. A model for long-distance dispersal of boll weevils (Coleoptera: Curculionidae)

    NASA Astrophysics Data System (ADS)

    Westbrook, John K.; Eyster, Ritchie S.; Allen, Charles T.

    2011-07-01

    The boll weevil, Anthonomus grandis (Boheman), has been a major insect pest of cotton production in the US, accounting for yield losses and control costs on the order of several billion US dollars since the introduction of the pest in 1892. Boll weevil eradication programs have eliminated reproducing populations in nearly 94%, and progressed toward eradication within the remaining 6%, of cotton production areas. However, the ability of weevils to disperse and reinfest eradicated zones threatens to undermine the previous investment toward eradication of this pest. In this study, the HYSPLIT atmospheric dispersion model was used to simulate daily wind-aided dispersal of weevils from the Lower Rio Grande Valley (LRGV) of southern Texas and northeastern Mexico. Simulated weevil dispersal was compared with weekly capture of weevils in pheromone traps along highway trap lines between the LRGV and the South Texas / Winter Garden zone of the Texas Boll Weevil Eradication Program. A logistic regression model was fit to the probability of capturing at least one weevil in individual pheromone traps relative to specific values of simulated weevil dispersal, which resulted in 60.4% concordance, 21.3% discordance, and 18.3% ties in estimating captures and non-captures. During the first full year of active eradication with widespread insecticide applications in 2006, the dispersal model accurately estimated 71.8%, erroneously estimated 12.5%, and tied 15.7% of capture and non-capture events. Model simulations provide a temporal risk assessment over large areas of weevil reinfestation resulting from dispersal by prevailing winds. Eradication program managers can use the model risk assessment information to effectively schedule and target enhanced trapping, crop scouting, and insecticide applications.

  18. A model for long-distance dispersal of boll weevils (Coleoptera: Curculionidae).

    PubMed

    Westbrook, John K; Eyster, Ritchie S; Allen, Charles T

    2011-07-01

    The boll weevil, Anthonomus grandis (Boheman), has been a major insect pest of cotton production in the US, accounting for yield losses and control costs on the order of several billion US dollars since the introduction of the pest in 1892. Boll weevil eradication programs have eliminated reproducing populations in nearly 94%, and progressed toward eradication within the remaining 6%, of cotton production areas. However, the ability of weevils to disperse and reinfest eradicated zones threatens to undermine the previous investment toward eradication of this pest. In this study, the HYSPLIT atmospheric dispersion model was used to simulate daily wind-aided dispersal of weevils from the Lower Rio Grande Valley (LRGV) of southern Texas and northeastern Mexico. Simulated weevil dispersal was compared with weekly capture of weevils in pheromone traps along highway trap lines between the LRGV and the South Texas/Winter Garden zone of the Texas Boll Weevil Eradication Program. A logistic regression model was fit to the probability of capturing at least one weevil in individual pheromone traps relative to specific values of simulated weevil dispersal, which resulted in 60.4% concordance, 21.3% discordance, and 18.3% ties in estimating captures and non-captures. During the first full year of active eradication with widespread insecticide applications in 2006, the dispersal model accurately estimated 71.8%, erroneously estimated 12.5%, and tied 15.7% of capture and non-capture events. Model simulations provide a temporal risk assessment over large areas of weevil reinfestation resulting from dispersal by prevailing winds. Eradication program managers can use the model risk assessment information to effectively schedule and target enhanced trapping, crop scouting, and insecticide applications.

  19. Effect of Hexaflumuron on gustation and reproduction of adult boll weevil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of hexaflumuron was evaluated in the laboratory against boll weevil, Anthonomus grandis grandis Boheman, captured in pheromone-baited traps for gustatory response and reproduction of the insect. Hexaflumuron is an insect growth regulator which inhibits chitin synthesis and disrupts inse...

  20. Quantification of dichlorvos released from kill strips used in boll weevil eradication programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two types of kill strips, Hercon Vaportape II and Plato Insecticide Strip, are used by boll weevil, Anthonomus grandis (Boheman), eradication programs in the U.S. Both types utilize dichlorvos as the killing agent and are marketed to last up to a month in traps. Consequently, programs typically re...

  1. Improving Cry8Ka toxin activity towards the cotton boll weevil (Anthonomus grandis)

    PubMed Central

    2011-01-01

    Background The cotton boll weevil (Anthonomus grandis) is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. In vitro directed molecular evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of Bacillus thuringiensis. Results Bioassays carried out with A. grandis larvae revealed that the LC50 of the screened mutant Cry8Ka5 toxin was 3.15-fold higher than the wild-type Cry8Ka1 toxin. Homology modelling of Cry8Ka1 and the Cry8Ka5 mutant suggested that both proteins retained the typical three-domain Cry family structure. The mutated residues were located mostly in loops and appeared unlikely to interfere with molecular stability. Conclusions The improved toxicity of the Cry8Ka5 mutant obtained in this study will allow the generation of a transgenic cotton event with improved potential to control A. grandis. PMID:21906288

  2. Longevity of adult boll weevils fed selected non-pollen food sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is known that substantial boll weevil, Anthonomus grandis grandis Boheman, populations survive subtropical winters in some habitats, such as citrus orchards. Our study shows that endocarps of the fruit from prickly pear cactus, Opuntia engelmannii Salm-Dyck ex. Engel.; and orange, Citrus sinensi...

  3. Temporal variability of spectral reflectance and estimated canopy cover of cotton plants supports early detection of potential boll weevil infestations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boll weevils may infest cotton fields when plants begin to produce squares, but eradication program managers may not be notified of fields that have been planted with cotton until after plants are already blooming. Because pheromone traps become much less effective in detecting weevil populations w...

  4. Boll weevil (Coleoptera: Curculionidae) response to and volitilization rates of grandlure when combined with varying doses of eugenol in the extended-life pheromone lure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boll weevil extended-life pheromone lures, impregnated with 25 mg grandlure and 30 mg eugenol, are replacing standard pheromone lures (10 mg grandlure) in boll weevil eradication programs, to increase the changing interval from 2 weeks, to 3 or 4 weeks, which reduces labor and material costs. The a...

  5. Genetic Profiling to Determine Potential Origins of Boll Weevils (Coleoptera: Curculionidae) Captured in a Texas Eradication Zone: Endemicity, Immigration, or Sabotage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Five specimens of adult boll weevil, Anthonomus grandis, were captured nearly simultaneously in pheromone traps clustered near Lubbock, TX, in the Southern High Plains/Caprock eradication zone in late summer 2006. No boll weevils had been captured in this zone or neighboring zones to the north earl...

  6. Rational Practices to Manage Boll Weevils Colonization and Population Growth on Family Farms in the Semiárido Region of Brazil.

    PubMed

    Neves, Robério C S; Colares, Felipe; Torres, Jorge B; Santos, Roberta L; Bastos, Cristina S

    2014-01-01

    Because boll weevil, Anthonomus grandis Boh. develops partially protected inside cotton fruiting structures, once they become established in a field, they are difficult to control, even with nearly continuous insecticide spray. During two cotton-growing seasons in the Semiárido region of Pernambuco State, Brazil, we tested the use of kaolin sprays to disrupt plant colonization through visual cue interference, combined with removal of fallen fruiting bodies to restrain boll weevil population growth after colonization. Kaolin spray under non-choice trials resulted in 2.2×, 4.4×, and 8.6× fewer weevils, oviposition and feeding punctures on kaolin-treated plants, respectively, despite demonstrating no statistical differences for colonization and population growth. Early season sprays in 2010 occurred during a period of rainfall, and hence, under our fixed spraying schedule no significant differences in boll weevil colonization were detected. In 2011, when kaolin sprays were not washed out by rain, delayed boll weevil colonization and reduction on attacked fruiting bodies were observed in eight out of 12 evaluations, and kaolin-treated plots had 2.7× fewer damaged fruiting bodies compared to untreated plots. Adoption of simple measures such as removal of fallen fruiting bodies and prompt reapplication of kaolin sprays after rainfall show promise in reducing boll weevil infestation. PMID:26462942

  7. Rational Practices to Manage Boll Weevils Colonization and Population Growth on Family Farms in the Semiárido Region of Brazil

    PubMed Central

    Neves, Robério C. S.; Colares, Felipe; Torres, Jorge B.; Santos, Roberta L.; Bastos, Cristina S.

    2014-01-01

    Because boll weevil, Anthonomus grandis Boh. develops partially protected inside cotton fruiting structures, once they become established in a field, they are difficult to control, even with nearly continuous insecticide spray. During two cotton-growing seasons in the Semiárido region of Pernambuco State, Brazil, we tested the use of kaolin sprays to disrupt plant colonization through visual cue interference, combined with removal of fallen fruiting bodies to restrain boll weevil population growth after colonization. Kaolin spray under non-choice trials resulted in 2.2×, 4.4×, and 8.6× fewer weevils, oviposition and feeding punctures on kaolin-treated plants, respectively, despite demonstrating no statistical differences for colonization and population growth. Early season sprays in 2010 occurred during a period of rainfall, and hence, under our fixed spraying schedule no significant differences in boll weevil colonization were detected. In 2011, when kaolin sprays were not washed out by rain, delayed boll weevil colonization and reduction on attacked fruiting bodies were observed in eight out of 12 evaluations, and kaolin-treated plots had 2.7× fewer damaged fruiting bodies compared to untreated plots. Adoption of simple measures such as removal of fallen fruiting bodies and prompt reapplication of kaolin sprays after rainfall show promise in reducing boll weevil infestation. PMID:26462942

  8. Genetic profiling to determine potential origins of boll weevils (Coleoptera: Curculionidae) captured in a Texas eradication zone: endemicity, immigration, or sabotage?

    PubMed

    Kim, Kyung Seok; Sappington, Thomas W; Allen, Charles T

    2008-12-01

    Thirty-seven boll weevils, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), were captured in pheromone traps near Lubbock, TX, in the Southern High Plains/Caprock eradication zone during August-October 2006. No boll weevils had been captured in this zone or neighboring zones to the north earlier in the year, and only very low numbers had been captured in neighboring zones to the south and east. Therefore, the captures near Lubbock were unexpected. Five of the weevils captured the last week of August were preserved and genotyped at 10 microsatellite loci for comparison with a database of genotypes for 22 boll weevil populations sampled from eight U.S. states and four locations in Mexico. The Lubbock population itself is an unlikely source, suggesting that the captured weevils probably did not originate from a low-level endemic population. Populations from eastern states, Mexico, and Big Spring, TX, can be confidently excluded as potential source regions. Although the Weslaco and Kingsville, TX, areas cannot be statistically excluded, they are unlikely sources. The most likely sources are nearby areas in New Mexico, TX, or southwest Oklahoma, or from areas of eastern Texas represented by Waxahachie and El Campo populations. Together, genetic and circumstantial evidence suggest either that the trapped boll weevils are the offspring of alone mated female that immigrated from eastern Texas earlier in the summer or that weevils originally captured near Waxahachie but now long-dead were planted in the traps by a disgruntled employee of the eradication program.

  9. Evaluation of the Boll Weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) suppression program in the state of Goiás, Brazil.

    PubMed

    de Lima, I S; Degrande, P E; Miranda, J E; dos Santos, W J

    2013-02-01

    The boll weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) is the most important cotton pest in Brazil. A large-scale field-testing of a Boll Weevil Suppression Program (BWSP) was implemented to assess its technical and operational feasibility for boll weevil suppression in the state of Goiás, Brazil. The pilot plan focused on 3,608 ha of cotton during the 2006/2007 and 6,011 ha in the 2007/2008 growing seasons; the areas were divided into four inner zones with an outer buffer zone. We analyzed data on boll weevil captures using pheromone traps installed in the BWSP fields, on the detection of the first insect and the first damaged floral bud, greatest damage, and number of insecticide applications. The nonparametric Mann-Whitney U test was used to evaluate the differences between presuppression and suppression years. Fourteen pheromone-baited trapping evaluations were used to compare the weevil populations from 2006/2007 and 2007/2008 growing seasons. The BWSP regime reduced in-season boll weevil captures from 15- to 500-fold compared to presuppression levels in the preceding year. The low capture rates were related to delays in infestation and damage by weevils. The smaller population size measured by trapping and field monitoring reduced the number of required insecticide treatments. The BWSP strategy was efficient in suppressing populations of this pest and is a viable program for cotton production in subtropical and tropical regions, with long-term economic and environmental benefits. PMID:23949716

  10. Semiochemicals from herbivory induced cotton plants enhance the foraging behavior of the cotton boll weevil, Anthonomus grandis.

    PubMed

    Magalhães, D M; Borges, M; Laumann, R A; Sujii, E R; Mayon, P; Caulfield, J C; Midega, C A O; Khan, Z R; Pickett, J A; Birkett, M A; Blassioli-Moraes, M C

    2012-12-01

    The boll weevil, Anthonomus grandis, has been monitored through deployment of traps baited with aggregation pheromone components. However, field studies have shown that the number of insects caught in these traps is significantly reduced during cotton squaring, suggesting that volatiles produced by plants at this phenological stage may be involved in attraction. Here, we evaluated the chemical profile of volatile organic compounds (VOCs) emitted by undamaged or damaged cotton plants at different phenological stages, under different infestation conditions, and determined the attractiveness of these VOCs to adults of A. grandis. In addition, we investigated whether or not VOCs released by cotton plants enhanced the attractiveness of the aggregation pheromone emitted by male boll weevils. Behavioral responses of A. grandis to VOCs from conspecific-damaged, heterospecific-damaged (Spodoptera frugiperda and Euschistus heros) and undamaged cotton plants, at different phenological stages, were assessed in Y-tube olfactometers. The results showed that volatiles emitted from reproductive cotton plants damaged by conspecifics were attractive to adults boll weevils, whereas volatiles induced by heterospecific herbivores were not as attractive. Additionally, addition of boll weevil-induced volatiles from reproductive cotton plants to aggregation pheromone gave increased attraction, relative to the pheromone alone. The VOC profiles of undamaged and mechanically damaged cotton plants, in both phenological stages, were not different. Chemical analysis showed that cotton plants produced qualitatively similar volatile profiles regardless of damage type, but the quantities produced differed according to the plant's phenological stage and the herbivore species. Notably, vegetative cotton plants released higher amounts of VOCs compared to reproductive plants. At both stages, the highest rate of VOC release was observed in A. grandis-damaged plants. Results show that A. grandis uses

  11. Transcriptome Analysis in Cotton Boll Weevil (Anthonomus grandis) and RNA Interference in Insect Pests

    PubMed Central

    Coelho, Roberta Ramos; Antonino de Souza Jr, José Dijair; Togawa, Roberto Coiti; Silva-Junior, Orzenil Bonfim; Pappas-Jr, Georgios Joannis; da Silva, Maria Cristina Mattar; Engler, Gilbert; Grossi-de-Sa, Maria Fatima

    2013-01-01

    Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families’ data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects. PMID:24386449

  12. Transcriptome analysis in cotton boll weevil (Anthonomus grandis) and RNA interference in insect pests.

    PubMed

    Firmino, Alexandre Augusto Pereira; Fonseca, Fernando Campos de Assis; de Macedo, Leonardo Lima Pepino; Coelho, Roberta Ramos; Antonino de Souza, José Dijair; Togawa, Roberto Coiti; Silva-Junior, Orzenil Bonfim; Pappas-Jr, Georgios Joannis; da Silva, Maria Cristina Mattar; Engler, Gilbert; Grossi-de-Sa, Maria Fatima

    2013-01-01

    Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.

  13. Employing in vitro directed molecular evolution for the selection of α-amylase variant inhibitors with activity toward cotton boll weevil enzyme.

    PubMed

    da Silva, Maria Cristina Mattar; Del Sarto, Rafael Perseghini; Lucena, Wagner Alexandre; Rigden, Daniel John; Teixeira, Fabíola Rodrigues; Bezerra, Caroline de Andrade; Albuquerque, Erika Valéria Saliba; Grossi-de-Sa, Maria Fatima

    2013-09-20

    Numerous species of insect pests attack cotton plants, out of which the cotton boll weevil (Anthonomus grandis) is the main insect in Brazil and must be controlled to avert large economic losses. Like other insect pests, A. grandis secretes a high level of α-amylases in the midgut lumen, which are required for digestion of carbohydrates. Thus, α-amylase inhibitors (α-AIs) represent a powerful tool to apply in the control of insect pests. Here, we applied DNA shuffling and phage display techniques and obtained a combinatorial library containing 10⁸ α-AI variant forms. From this library, variants were selected exhibiting in vitro affinity for cotton boll weevil α-amylases. Twenty-six variant sequences were cloned into plant expression vectors and expressed in Arabidopsis thaliana. Transformed plant extracts were assayed in vitro to select specific and potent α-amylase inhibitors against boll weevil amylases. While the wild type inhibitors, used to create the shuffled library, did not inhibit the A. grandis α-amylases, three α-AI mutants, named α-AIC3, α-AIA11 and α-AIG4 revealed high inhibitory activities against A. grandis α-amylases in an in vitro assay. In summary, data reported here shown the potential biotechnology of new α-AI variant genes for cotton boll weevil control.

  14. Efficiency of Tank-Mixing Insecticide with Defoliant Against Adult Boll Weevil (Coleoptera:Curculionidae) Populations as Determined by Late-Season Field Disturbance Trapping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large commercial field plots were used to assess the effect of tank-mixing cyfluthrin with a defoliant applied in preparation for cotton, Gossypium hirsutum L., harvest on adult boll weevil, Anthonomus grandis grandis Boheman, populations in south Texas during 2002 and 2003. The defoliant-insectici...

  15. Activity of a Brazilian strain of Bacillus thuringiensis israelensis against the cotton Boll Weevil Anthonomus grandis Boheman (Coleoptera: Tenebrionidae).

    PubMed

    Monnerat, R; Martins, E; Praça, L; Dumas, V; Berry, C

    2012-02-01

    A Brazilian Bacillus thuringiensis subspecies israelensis, toxic to Diptera, including mosquitoes, was found also to show toxicity to the coleopteran boll weevil Anthonomus grandis Boheman at an equivalent level to that of the standard coleopteran-active B. thuringiensis subspecies tenebrionis T08017. Recombinant B. thuringiensis strains expressing the individual Cyt1Aa, Cry4Aa, Cry4Ba and Cry11Aa toxins from this strain were assessed to evaluate their potential contribution to the activity against A. grandis, either alone or in combination. Whilst individual toxins produced mortality, none was sufficiently potent to allow calculation of LC50 values. Combinations of toxins were unable to attain the same potency as the parental B. thuringiensis subsp. israelensis, suggesting a major role for other factors produced by this strain. PMID:23950011

  16. Deterrent effects of four neem-based formulations on gravid female boll weevil (Coleoptera: Curculionidae) feeding and oviposition on cotton squares.

    PubMed

    Showler, A T; Greenberg, S M; Arnason, J T

    2004-04-01

    Three commercial neem-based insecticides, Agroneem, Ecozin, and Neemix, and a neem seed extract formulation, bitters, containing 1,036, 16,506, 471, and 223 microg/ml azadirachtin, respectively, were assessed for feeding and oviposition deterrence against gravid female boll weevils, Anthonomus grandis grandis Boheman, in the laboratory. In choice assays, excised cotton squares dipped in the separate formulations were first physically contacted by the weevils' tarsi or antennae fewer times than nontreated control squares. In choice and no-choice assays, each formulation repelled the weevils for > or = 90 min. After 24 h in the choice assays, feeding punctures on the squares treated with Agroneem, Ecozin, or bitters were significantly fewer compared with controls. Egg punctures on the Ecozin- and the bitters-treated squares were significantly fewer than on control squares after 24 h. In the no-choice assay, no significant difference was detected. Aging the formulations under outdoor conditions for 24 h before weevils were exposed resulted in 46-60% and 62-82% reductions in feeding and oviposition punctures, respectively, compared with controls. Agroneem- and bitters-treated squares had > 37% fewer feeding punctures after being aged for 48 h. No significant difference was detected after 72 h of aging. Because the deterrence of the gravid female boll weevils was not correlated with amounts of azadirachtin, azadirachtin does not seem to be the only, or the most influential, component of neem that induced the observed deterrence. PMID:15154463

  17. Selection of Beauveria bassiana sensu lato and Metarhizium anisopliae sensu lato isolates as microbial control agents against the boll weevil (Anthonomus grandis) in Argentina.

    PubMed

    Nussenbaum, A L; Lecuona, R E

    2012-05-01

    The boll weevil (Anthonomus grandis) is the main pest of cotton in the Americas. The aim of this work was to evaluate isolates of the entomopathogenic fungi Beauveria bassiana sensu lato and Metarhizium anisopliae sensu lato virulent against A. grandis. Screening was performed to evaluate the pathogenicity of 28 isolates of M. anisopliae s.l. and 66 isolates of B. bassiana s.l. against boll weevil adults. To select the isolates, LC(50) values of the most virulent isolates were calculated, and compatibility between the fungi and insecticides was studied. In addition, the effects of these isolates on the feeding behavior of the adults were evaluated. Isolates Ma 50 and Ma 20 were the most virulent against A. grandis and their LC(50) values were 1.13×10(7) and 1.20×10(7) conidia/ml, respectively. In addition, these isolates were compatible with pyrethroid insecticides, but none with endosulfan. On the other hand, infected females reduced the damage caused by feeding on the cotton squares and their weight gain. This shows that entomopathogenic fungi cause mortality in the insects, but also these fungi could influence the feeding behavior of the females. In summary, these results indicate the possibility of the use of M. anisopliae s.l. as a microbiological control agent against boll weevils. Also, this species could be included in an Integrated Pest Management program.

  18. Vitellogenin knockdown strongly affects cotton boll weevil egg viability but not the number of eggs laid by females.

    PubMed

    Coelho, Roberta R; de Souza Júnior, José Dijair Antonino; Firmino, Alexandre A P; de Macedo, Leonardo L P; Fonseca, Fernando C A; Terra, Walter R; Engler, Gilbert; de Almeida Engler, Janice; da Silva, Maria Cristina M; Grossi-de-Sa, Maria Fatima

    2016-09-01

    Vitellogenin (Vg), a yolk protein precursor, is the primary egg nutrient source involved in insect reproduction and embryo development. The Cotton Boll weevil (CBW) Anthonomus grandis Boheman, the most important cotton pest in Americas, accumulates large amounts of Vg during reproduction. However, the precise role of this protein during embryo development in this insect remains unknown. Herein, we investigated the effects of vitellogenin (AgraVg) knockdown on the egg-laying and egg viability in A. grandis females, and also characterized morphologically the unviable eggs. AgraVg transcripts were found during all developmental stages of A. grandis, with highest abundance in females. Silencing of AgraVg culminated in a significant reduction in transcript amount, around 90%. Despite this transcriptional reduction, egg-laying was not affected in dsRNA-treated females but almost 100% of the eggs lost their viability. Eggs from dsRNA-treated females showed aberrant embryos phenotype suggesting interference at different stages of embryonic development. Unlike for other insects, the AgraVg knockdown did not affect the egg-laying ability of A. grandis, but hampered A. grandis reproduction by perturbing embryo development. We concluded that the Vg protein is essential for A. grandis reproduction and a good candidate to bio-engineer the resistance against this devastating cotton pest. PMID:27419079

  19. Vitellogenin knockdown strongly affects cotton boll weevil egg viability but not the number of eggs laid by females.

    PubMed

    Coelho, Roberta R; de Souza Júnior, José Dijair Antonino; Firmino, Alexandre A P; de Macedo, Leonardo L P; Fonseca, Fernando C A; Terra, Walter R; Engler, Gilbert; de Almeida Engler, Janice; da Silva, Maria Cristina M; Grossi-de-Sa, Maria Fatima

    2016-09-01

    Vitellogenin (Vg), a yolk protein precursor, is the primary egg nutrient source involved in insect reproduction and embryo development. The Cotton Boll weevil (CBW) Anthonomus grandis Boheman, the most important cotton pest in Americas, accumulates large amounts of Vg during reproduction. However, the precise role of this protein during embryo development in this insect remains unknown. Herein, we investigated the effects of vitellogenin (AgraVg) knockdown on the egg-laying and egg viability in A. grandis females, and also characterized morphologically the unviable eggs. AgraVg transcripts were found during all developmental stages of A. grandis, with highest abundance in females. Silencing of AgraVg culminated in a significant reduction in transcript amount, around 90%. Despite this transcriptional reduction, egg-laying was not affected in dsRNA-treated females but almost 100% of the eggs lost their viability. Eggs from dsRNA-treated females showed aberrant embryos phenotype suggesting interference at different stages of embryonic development. Unlike for other insects, the AgraVg knockdown did not affect the egg-laying ability of A. grandis, but hampered A. grandis reproduction by perturbing embryo development. We concluded that the Vg protein is essential for A. grandis reproduction and a good candidate to bio-engineer the resistance against this devastating cotton pest.

  20. Chemical cotton stalk destruction for maintenance of host-free periods for the control of overwintering boll weevil in tropical and subtropical climates.

    PubMed

    Greenberg, Shoil M; Sparks, Alton N; Norman, John W; Coleman, Randy; Bradford, Joe M; Yang, Chenghai; Sappington, Thomas W; Showler, Allan

    2007-04-01

    In the Lower Rio Grande Valley (LRGV) of Texas, cotton regrows and produces fruit from undestroyed stalks throughout the winter, and in spring weevils from such locations become a serious threat. The success of the boll weevil eradication program, which was reintroduced in the LRGV in 2005, will be dependent on thorough stalk destruction following harvest. However, adverse weather conditions and conservation tillage often impede immediate and complete stalk destruction using typical tool implements, and alternative stalk control methods are needed. This study provides an examination of the efficacy for cotton stalk destruction of different herbicides (thifensulfuron-methyl + tribenuron-methyl, dicamba-diolamine, 2,4-D-dimethylammonium, flumioxazin, 2,4-DB-dimethylammonium and carfentrazone-ethyl) and their rates, spray volumes and application timings on shredded or standing cotton stalks after stripper or picker harvest. None of the tested herbicides, except 2,4-D-dimethylammonium, stopped post-harvest cotton regrowth and fruiting. 2,4-D-dimethylammonium sprayed once (0 or 7 days) after cotton was harvested at 1 lb AE acre(-1) (1.12 kg ha(-1)), in a spray volume of 10 gal water acre(-1) (93.5 L ha(-1)) with 5 mL L(-1) surfactant, was highly effective in stalk destruction (72-90%). The best results were achieved when the herbicide was applied immediately after the cotton was shredded, followed by standing stripper-harvested and standing picker-harvested cotton. 2,4-D-dimethylammonium applied twice, 0 and 14 (or 21) days after cotton harvest, was 100% effective in killing stalks, regardless of whether they were shredded or standing, or whether harvest was by stripper or picker. These findings showed that 2,4-D-dimethylammonium cotton stalk destruction eliminated food and reproductive opportunities for managing overwintering boll weevils [Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae)].

  1. Attraction of milkweed stem weevils, Rhyssomatus spp. (Coleoptera: Curculiondae), to grandlure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A trapping study was initiated in the spring of 2010 to compare the attraction of boll weevils to standard grandlure (synthesized boll weevil pheromone) and a new experimental formulation of grandlure. Both formulations contained the same four pheromone components, but differed in the proportion of...

  2. [Effects of drought and waterlogging on carbohydrate contents of cotton boll and its relationship with boll biomass accumulation at the flowering and bolling stage].

    PubMed

    Yang, Chang-Qin; Liu, Jing-Ran; Zhang, Guo-Wei; Liu, Rui-Xian; Zhou, Zhi-Guo

    2014-08-01

    Cotton cultivar NuCOTN 33B was planted in isolated pools treated with drought or waterlogging for 7 or 14 d to explore their effects on cotton boll carbohydrate content and its relationship with the biomass accumulation. The results showed that the drought treatment reduced the carbohydrate content of cotton boll shell on middle fruit branches, but had a weak effect on cotton boll shells on lower fruit branches. Soluble sugar, starch and sucrose contents of cotton boll shell on upper fruit branches under the drought condition and on whole plant branches under waterlogging treatment changed similarly, namely, the soluble sugar and starch content increased, while the sucrose content went down firstly and then increased later, which indicated that the exportation of sucrose from boll shell was inhibited and became worse with the increase of waterlogging duration. Compared with the boll shell, the carbohydrate contents of cotton seed were less affected by the drought and waterlogging treatments at the flowering and bolling stage. Under the treatments of drought and 7 d-waterlogging, the biomass accumulation of cotton bolls on the middle fruit branches initiated earlier but lasted less days, and the maximum speed at lower and upper fruit branches reduced, while the treatment of waterlogging for 14 d caused the decline of maximum speed of biomass accumulation of bolls on whole branches. On the other side, the correlation analysis showed the significant positive relationships among the boll biomass, the maximum speed and the contents of soluble sugar and sucrose in the boll shell respectively. In conclusion, the treatment of drought and waterlogging at the flowering and bolling stage retarded the outward transportation of sucrose from cotton bolls, changed the boll biomass accumulation characteristics, and therefore were detected as the important cause of cotton boll total biomass reduction.

  3. Detecting cotton boll rot with an electronic nose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    South Carolina Boll Rot is an emerging disease of cotton, Gossypium hirsutum L., caused by the opportunistic bacteria, Pantoea agglomerans (Ewing and Fife). Unlike typical fungal diseases, bolls infected with P. agglomerans continue to appear normal externally, complicating early and rapid detectio...

  4. Waterlogging during flowering and boll forming stages affects sucrose metabolism in the leaves subtending the cotton boll and its relationship with boll weight.

    PubMed

    Kuai, Jie; Liu, Zhaowei; Wang, Youhua; Meng, Yali; Chen, Binglin; Zhao, Wenqing; Zhou, Zhiguo; Oosterhuis, Derrick M

    2014-06-01

    The work explored sucrose metabolism in the leaves subtending the cotton boll (SBL) and its role in boll weight after waterlogging in cotton. Results showed that net photosynthesis rate (Pn), relative water content, contents of Chlorophyll a and Chlorophyll b, initial ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) activity and cytosolic fructose-1, 6-bisphosphatase (cy-FBPase) activity decreased with waterlogging in the SBL on fruiting branches 2-3 (FB2-3) and FB6-7. Activities of sucrose synthase (SuSy) and sucrose phosphate synthase (SPS) increased to the maximum up to 6 days of waterlogging then decreased with prolonged waterlogging. Rubisco activation and specific leaf weight increased and gene expressions of SuSy, SPS and rubisco activase (RCA) were all up-regulated with the duration of waterlogging, especially for the SBL on FB6-7. The induction of activity and gene expression of SuSy was most significant indicating its crucial role in sucrose metabolism after waterlogging. For the SBL in the later period of boll development on upper FB10-11 and FB14-15, the pattern seemed opposite to that of FB2-3 and FB6c7 as compensation effect in vegetative growth existed. Correlation analysis revealed that initial Rubisco activity and cy-FBPase activity were the main limitation to Pn reduction after waterlogging. Reduction in Pn, sucrose transformation rate and initial Rubisco activity directly decrease boll weight in waterlogged cotton. Besides the role in sucrose metabolism after waterlogging, SuSy also had a positive significant correlation with the duration of rapid-accumulation period for seed fiber weight (P<0.05). These findings elucidated mechanisms to waterlogging that affected seed fiber weight, which resulted from alteration in carbohydrates, enzymes and genes.

  5. Palm Weevil Pheromones - Discovery and Use.

    PubMed

    Oehlschlager, A C

    2016-07-01

    Male-produced aggregation pheromones of seven major pest species of weevils in the subfamily Rhynchophorinae have been identified as a closely related set of methyl-branched secondary alcohols. Although the weevils produce only one stereoisomer of these alcohols, no instances of isomeric inhibition have been observed, enabling stereoisomeric mixtures to be used in traps. Addition of fermenting plant material to traps synergizes attraction of weevils to the pheromones. The weevils are large, have long life cycles, and are strong fliers. These characteristics make mass trapping a suitable tactic to add to existing management strategies. When coupled with good phytosanitary practices, mass trapping of Rhynchophorus palmarum at 1 trap/5-ha significantly lowered the incidence of red ring nematode infection vectored by the weevil in commercial oil palm plantations in the Americas. Similarly, trap densities of 1-10 traps/ha have significantly lowered R. ferrugineus infestation of date palm throughout the Middle East. Although management of R. ferrugineus in urban areas is more problematic, trapping is an integral part of most programs aimed at protection of ornamental Canary palms in Europe. Overall, semiochemically-based management of these large weevils is now a mature and usually economically feasible control technology. PMID:27430563

  6. Temperature regime and carbon dioxide enrichment alter cotton boll development and fiber properties

    SciTech Connect

    Reddy, K.R.; Davidonis, G.H.; Johnson, A.S.; Vinyard, B.T.

    1999-10-01

    Temperature and atmospheric carbon dioxide concentration [CO{sub 2}] affect cotton (Gossypium hirsutum L.) growth and development, but the interaction of these two factors on bill and fiber properties has not been studied. An experiment was conducted in naturally lit plant growth chambers to determine the influence of temperature and atmospheric [CO{sub 2}] on cotton (cv. DPL-51) boll and fiber growth parameters. Five temperature regimes were evaluated: the 1995 temperature at Mississippi State, MS; the 1995 temperature minus 2 C; and the 1995 temperature plus 2, 5, and 7 C. Daily and seasonal variation and amplitudes were maintained. Atmospheric [CO{sub 2}] treatments were 360 (ambient) and 720 {micro}L L{sup {minus}1}. Boll number, boll growth, and fiber properties were measured. Boll size and maturation periods decreased as temperature increased. Boll growth increased with temperature to 25 C and then declined at the highest temperature. Boll maturation period, size, and growth rates were not affected by atmospheric [CO{sub 2}]. The most temperature-sensitive aspect of cotton development is boll retention. Almost no bolls were retained to maturity at 1995 plus 5 or 7 C, but squares and bolls were continuously produced even at those high temperatures. Therefore, the upper limit for cotton boll survival is 32 C, or 5 C warmer than the 1995 US Mid-South ambient temperatures. The 720 {micro}L L{sup {minus}1} atmospheric [CO{sub 2}] had about 40% more squares and bolls across temperatures than the 360 {micro}L L{sup {minus}1} [CO{sub 2}]. Fibers were longer when bolls grew at less than optimal temperatures (25 C) for boll growth. As temperature increased, fiber length distributions were more uniform. Fiber fineness and maturity increased linearly with the increase in temperature up to 26 C, but decreased at 32 C. Short-fiber content declined linearly from 17 to 26 C, but was higher at higher temperature. As for boll growth and developmental parameters, elevated

  7. Rice weevil response to basil oil fumigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Basil oil, Ocimum basilicum L., is a volatile plant essential oil that is known to have insecticidal activity against stored product pests such as rice weevil, Sitophilus oryzae (L.). Basil oil was diluted in acetone and applied to a sponge held inside a tea strainer for fumigations in containers wi...

  8. Actual and simulated injury of Creontiades signatus (Heteroptera: Miridae) feeding on cotton bolls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The actual feeding injury of Creontiades signatus (Distant) was compared to a simulated technique for study years 2005, 2006 and 2008 by injecting varying dilutions of pectinase into cotton bolls at different boll sizes (ages) in an effort to determine if such a technique could be used to reduce the...

  9. Isolation of bacteria from cotton bolls in the Texas Coastal Bend and Rio Grande Valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boll rots have caused a reduction in yield, lint quality, and increased contaminated seed. During 2011 and 2012 field surveys were conducted throughout the Texas Coastal Bend and Rio Grande Valley to determine incidence of cotton boll rot. A variety trial was conducted using the top five varieties...

  10. Comparison of cotton square and boll damage and resulting lint and seed loss caused by verde plant bug, Creontiades signatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Retention of bolls and squares (referred to as fruit retention), boll damage, and resulting cotton lint and seed weight loss were assessed when two (2010) and three (2011) age classes of sympodial fruiting branches with different ages of squares and bolls where exposed to verde plant bug, Creontiade...

  11. LED-Induced fluorescence and image analysis to detect stink bug damage in cotton bolls

    PubMed Central

    2013-01-01

    Background Stink bugs represent a major agricultural pest complex attacking more than 200 wild and cultivated plants, including cotton in the southeastern US. Stink bug feeding on developing cotton bolls will cause boll abortion or lint staining and thus reduced yield and lint value. Current methods for stink bug detection involve manual harvesting and cracking open of a sizable number of immature cotton bolls for visual inspection. This process is cumbersome, time consuming, and requires a moderate level of experience to obtain accurate estimates. To improve detection of stink bug feeding, we present here a method based on fluorescent imaging and subsequent image analyses to determine the likelihood of stink bug damage in cotton bolls. Results Damage to different structures of cotton bolls including lint and carpal wall can be observed under blue LED-induced fluorescence. Generally speaking, damaged regions fluoresce green, whereas non-damaged regions with chlorophyll fluoresce red. However, similar fluorescence emission is also observable on cotton bolls that have not been fed upon by stink bugs. Criteria based on fluorescent intensity and the size of the fluorescent spot allow to differentiate between true positives (fluorescent regions associated with stink bug feeding) and false positives (fluorescent regions due to other causes). We found a detection rates with two combined criteria of 87% for true-positive marks and of 8% for false-positive marks. Conclusions The imaging technique presented herein gives rise to a possible detection apparatus where a cotton boll is imaged in the field and images processed by software. The unique fluorescent signature left by stink bugs can be used to determine with high probability if a cotton boll has been punctured by a stink bug. We believe this technique, when integrated in a suitable device, could be used for more accurate detection in the field and allow for more optimized application of pest control. PMID:23421982

  12. Aggregation and Association of NDVI, Boll Injury, and Stink Bugs in North Carolina Cotton.

    PubMed

    Reisig, Dominic D; Reay-Jones, F P F; Meijer, A D

    2015-01-01

    Sampling of herbivorous stink bugs in southeastern U.S. cotton remains problematic. Remote sensing was explored to improve sampling of these pests and associated boll injury. Two adjacent 14.5-ha cotton fields were grid sampled in 2011 and 2012 by collecting stink bug adults and bolls every week during the third, fourth, and fifth weeks of bloom. Satellite remote sensing data were collected during the third week of bloom during both years, and normalized difference vegetation index (NDVI) values were calculated. Stink bugs were spatially aggregated on the third week of bloom in 2011. Boll injury from stink bugs was spatially aggregated during the fourth week of bloom in 2012. The NDVI values were aggregated during both years. There was a positive association and correlation between stink bug numbers and NDVI values, as well as injured bolls and NDVI values, during the third week of bloom in 2011. During the third week of bloom in 2012, NDVI values were negatively correlated with stink bug numbers. During the fourth week of bloom in 2011, stink bug numbers and boll injury were both positively associated and correlated with NDVI values. During the fourth week of bloom in 2012, stink bugs were negatively correlated with NDVI values, and boll injury was negatively associated and correlated with NDVI values. This study suggests the potential of remote sensing as a tool to assist with sampling stink bugs in cotton, although more research is needed using NDVI and other plant measurements to predict stink bug injury.

  13. Aggregation and Association of NDVI, Boll Injury, and Stink Bugs in North Carolina Cotton.

    PubMed

    Reisig, Dominic D; Reay-Jones, F P F; Meijer, A D

    2015-01-01

    Sampling of herbivorous stink bugs in southeastern U.S. cotton remains problematic. Remote sensing was explored to improve sampling of these pests and associated boll injury. Two adjacent 14.5-ha cotton fields were grid sampled in 2011 and 2012 by collecting stink bug adults and bolls every week during the third, fourth, and fifth weeks of bloom. Satellite remote sensing data were collected during the third week of bloom during both years, and normalized difference vegetation index (NDVI) values were calculated. Stink bugs were spatially aggregated on the third week of bloom in 2011. Boll injury from stink bugs was spatially aggregated during the fourth week of bloom in 2012. The NDVI values were aggregated during both years. There was a positive association and correlation between stink bug numbers and NDVI values, as well as injured bolls and NDVI values, during the third week of bloom in 2011. During the third week of bloom in 2012, NDVI values were negatively correlated with stink bug numbers. During the fourth week of bloom in 2011, stink bug numbers and boll injury were both positively associated and correlated with NDVI values. During the fourth week of bloom in 2012, stink bugs were negatively correlated with NDVI values, and boll injury was negatively associated and correlated with NDVI values. This study suggests the potential of remote sensing as a tool to assist with sampling stink bugs in cotton, although more research is needed using NDVI and other plant measurements to predict stink bug injury. PMID:26411787

  14. Aggregation and Association of NDVI, Boll Injury, and Stink Bugs in North Carolina Cotton

    PubMed Central

    Reisig, Dominic D.; Reay-Jones, F. P. F.; Meijer, A. D.

    2015-01-01

    Sampling of herbivorous stink bugs in southeastern U.S. cotton remains problematic. Remote sensing was explored to improve sampling of these pests and associated boll injury. Two adjacent 14.5-ha cotton fields were grid sampled in 2011 and 2012 by collecting stink bug adults and bolls every week during the third, fourth, and fifth weeks of bloom. Satellite remote sensing data were collected during the third week of bloom during both years, and normalized difference vegetation index (NDVI) values were calculated. Stink bugs were spatially aggregated on the third week of bloom in 2011. Boll injury from stink bugs was spatially aggregated during the fourth week of bloom in 2012. The NDVI values were aggregated during both years. There was a positive association and correlation between stink bug numbers and NDVI values, as well as injured bolls and NDVI values, during the third week of bloom in 2011. During the third week of bloom in 2012, NDVI values were negatively correlated with stink bug numbers. During the fourth week of bloom in 2011, stink bug numbers and boll injury were both positively associated and correlated with NDVI values. During the fourth week of bloom in 2012, stink bugs were negatively correlated with NDVI values, and boll injury was negatively associated and correlated with NDVI values. This study suggests the potential of remote sensing as a tool to assist with sampling stink bugs in cotton, although more research is needed using NDVI and other plant measurements to predict stink bug injury. PMID:26411787

  15. [Effects of high temperature on Bt protein content and nitrogen metabolic physiology in boll wall of Bt cotton].

    PubMed

    Wang, Jun; Abidallah, Eltayib H M A; Hua, Ming-ming; Heng, Li; Lyu, Chun-hua; Chen, De-hua

    2015-10-01

    Bt cotton cultivar Sikang 1 (a conventional cultivar) and Sikang 3 (a hybrid cultivar) from China, and 99B (a conventional cultivar) and Daiza 1 (a hybrid cultivar) from USA were selected as experimental materials, the ball wall Bt protein content and nitrogen metabolic physiology were investigated under different high temperature levels at peak boll stage. The results showed that the Bt protein content of boll wall decreased with the increasing temperature. Compared with the control (32 °C, the boll wall Bt protein content decreased significantly when the temperature was above 38 °C for the conventional cultivars and above 40 °C for the hybrid cultivars. The Bt protein contents of cultivar Sikang 1 and 99B decreased by 53.0% and 69.5% respectively with the temperature at 38 °C, and that of cultivar Sikang 3 and Daiza 1 decreased by 64.8% and 54.1% respectively with the temperature at 40 °C. Greater reductions in the boll wall soluble protein contents and GPT activities, larger increments for the boll wall free amino acid contents and proteinsase activities were also observed when the boll wall Bt protein content was significantly reduced. Therefore, high temperature resulted in the reduction of Bt protein synthesis and increase of the insecticidal protein degradation in the boll wall significantly, which caused the reductions in boll wall Bt protein content and insect resistance. PMID:26995932

  16. How Far Can the Red Palm Weevil (Coleoptera: Curculionidae) Fly?: Computerized Flight Mill Studies With Field-Captured Weevils.

    PubMed

    Hoddle, M S; Hoddle, C D; Faleiro, J R; El-Shafie, H A F; Jeske, D R; Sallam, A A

    2015-12-01

    Adult Rhynchophorus ferrugineus (Olivier) captured in pheromone-baited traps in commercial date palm orchards in the Al Ahsaa Directorate, Kingdom of Saudi Arabia, were used in computerized flight mill studies to determine the flight characteristics of this highly invasive and destructive palm pest. Flight mill studies were run at three different time periods, winter (December), spring (March), and summer (May). Of the 192 weevils tethered to flight mills ∼30% failed to fly > 1 km. Of those weevils flying > 1 km (n = 139), 55% flew > 10 km, and of these flyers 5% flew > 50 km in 24 h. Flying weevils exhibited an average weight loss of 20-30% and nonflying control weevils lost ∼9-13% body weight in 24 h. Male and female weevils flying in summer (average laboratory temperature was ∼27°C) flew the longest average distances (∼25-35 km), exhibited highest weight reductions (∼30%), and greatest mortality rates (∼80%). Consequently, time of year not weevil sex or color morph had a consistent and significant effect on flight activity, weight loss, and survivorship rates. Flight activity was predominantly diurnal commencing around 5:00 a.m. and peaking between 9-11:00 a.m. before tapering off. The distribution of flight distances combined across season and sex was mesokurtic (i.e., normally distributed).

  17. Methods for assessing infestations of sunflower stem weevil (Coleoptera: Curculionidae) in sunflower stems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sunflower stem weevil, Cylindrocopturus adspersus LeConte (Coleoptera: Curculionidae), reduces sunflower, Helianthus annuus L. (Asteraceae), yields by spreading pathogens, damaging vascular tissues, and promoting lodging of sunflower plants. To assess weevil populations for host plant resistanc...

  18. Biological role of Nardonella endosymbiont in its weevil host.

    PubMed

    Kuriwada, Takashi; Hosokawa, Takahiro; Kumano, Norikuni; Shiromoto, Keiko; Haraguchi, Dai; Fukatsu, Takema

    2010-01-01

    Weevils constitute the most species-rich animal group with over 60,000 described species, many of which possess specialized symbiotic organs and harbor bacterial endosymbionts. Among the diverse microbial associates of weevils, Nardonella spp. represent the most ancient and widespread endosymbiont lineage, having co-speciated with the host weevils for over 125 million years. Thus far, however, no empirical work on the role of Nardonella for weevil biology has been reported. Here we investigated the biological role of the Nardonella endosymbiont for the West Indian sweet potato weevil, Euscepes postfasciatus. This insect is an experimentally tractable pest insect that can easily be reared on a natural diet of sweet potato root as well as on an agar-based artificial diet. By larval feeding on an antibiotic-containing artificial diet, Nardonella infection was effectively eliminated from the treated insects. The antibiotic-treated insects exhibited significantly lighter body weight and lower growth rate than the control insects. Then, the antibiotic-treated insects and the control insects were respectively allowed to mate and oviposit on fresh sweet potatoes without the antibiotic. The offspring of the antibiotic-treated insects, which were all Nardonella-negative, exhibited significantly lighter body weight, smaller body size, lower growth rate and paler body color in comparison with the offspring of the control insects, which were all Nardonella-positive. In conclusion, the Nardonella endosymbiont is involved in normal growth and development of the host weevil. The biological role of the endosymbiont probably underlies the long-lasting host-symbiont co-speciation in the evolutionary course of weevils.

  19. [Sexual dimorphism of guava weevil Conotrachelus psidii Marshall (Coleoptera: Curculionidae)].

    PubMed

    Silva-Filho, Gilson; Bailez, Omar E; Viana-Bailez, Ana M

    2007-01-01

    We investigate structural and behavioral differences between male and female adults of guava weevil, Conotrachelus psidii Marshall, 1922 to help in sex determination. Weevils collected from a commercial guava orchard were individually caged and maintained under laboratory conditions. Every day ten individuals were grouped and their behavior was observed. During mating the males and females were identified. Fifty weevils of each sex were killed and they were observed with stereoscopic microscope. The antenna insertion on the rostrum and hair on the thorax and abdomen surfaces were examined. Length and width of body, pronotum, last abdominal sternite and rostrum were also taken. Behaviorally, the male weevils produce audible sound by stridulation of abdomen while females do not. In the females, the body and pronotum width and body a rostrum length were higher than in the males, but the last abdominal sternite was smaller. Three other structural differences were visible with the naked eye: 1) the anterior region of pronotum have scarce hair or have not in the females and hair is dense in the males; 2) the last tergite of females is hidden by the penultimate tergite whereas in the males is visible; 3) the first abdominal sternite of females is more prominent, very convex and without or with little bristle. In the males it is slightly concave and with abundant hair. The male-female differences found in this work allow, without hurt or change insect behavior, an efficient sex determination of guava weevil. PMID:17934614

  20. The Phytotoxin Coronatine Induces Abscission-Related Gene Expression and Boll Ripening during Defoliation of Cotton

    PubMed Central

    Tian, Xiaoli; Duan, Liusheng; Zhang, Mingcai; Tan, Weiming; Xu, Dongyong; Li, Zhaohu

    2014-01-01

    Defoliants can increase machine harvest efficiency of cotton (Gossypium hirusutum L.), prevent lodging and reduce the time from defoliation to harvest. Coronatine (COR) is a chlorosis-inducing non-host-specific phytotoxin that induces leaf and/or fruit abscission in some crops. The present study investigates how COR might induce cotton leaf abscission by modulating genes involved in cell wall hydrolases and ACC (ethylene precursor) in various cotton tissues. The effects of COR on cotton boll ripening, seedcotton yield, and seed development were also studied. After 14 d of treatment with COR, cells within the leaf abscission zone (AZ) showed marked differentiation. Elevated transcripts of GhCEL1, GhPG and GhACS were observed in the AZs treated with COR and Thidiazuron (TDZ). The relative expression of GhCEL1 and GhACS in TDZ treated plants was approximately twice that in plants treated with COR for 12 h. However, only GhACS expression increased in leaf blade and petiole. There was a continuous increase in the activity of hydrolytic enzymes such as cellulase (CEL) and polygalacturonase (PG), and ACC accumulation in AZs following COR and TDZ treatments, but there was greater increase in ACC activity of COR treated boll crust, indicating that COR had greater ripening effect than TDZ. Coronatine significantly enhanced boll opening without affecting boll weight, lint percentage and seed quality. Therefore, COR can be a potential cotton defoliant with different physiological mechanism of action from the currently used TDZ. PMID:24845465

  1. T & I--Textiles, Cotton Boll. Kit No. 59. Instructor's Manual [and] Student Learning Activity Guide.

    ERIC Educational Resources Information Center

    Buddin, David

    An instructor's manual and student activity guide on the cotton boll are provided in this set of prevocational education materials which focuses on the vocational area of trade and industry (textiles). (This set of materials is one of ninety-two prevocational education sets arranged around a cluster of seven vocational offerings: agriculture, home…

  2. The phytotoxin coronatine induces abscission-related gene expression and boll ripening during defoliation of cotton.

    PubMed

    Du, Mingwei; Li, Yi; Tian, Xiaoli; Duan, Liusheng; Zhang, Mingcai; Tan, Weiming; Xu, Dongyong; Li, Zhaohu

    2014-01-01

    Defoliants can increase machine harvest efficiency of cotton (Gossypium hirusutum L.), prevent lodging and reduce the time from defoliation to harvest. Coronatine (COR) is a chlorosis-inducing non-host-specific phytotoxin that induces leaf and/or fruit abscission in some crops. The present study investigates how COR might induce cotton leaf abscission by modulating genes involved in cell wall hydrolases and ACC (ethylene precursor) in various cotton tissues. The effects of COR on cotton boll ripening, seedcotton yield, and seed development were also studied. After 14 d of treatment with COR, cells within the leaf abscission zone (AZ) showed marked differentiation. Elevated transcripts of GhCEL1, GhPG and GhACS were observed in the AZs treated with COR and Thidiazuron (TDZ). The relative expression of GhCEL1 and GhACS in TDZ treated plants was approximately twice that in plants treated with COR for 12 h. However, only GhACS expression increased in leaf blade and petiole. There was a continuous increase in the activity of hydrolytic enzymes such as cellulase (CEL) and polygalacturonase (PG), and ACC accumulation in AZs following COR and TDZ treatments, but there was greater increase in ACC activity of COR treated boll crust, indicating that COR had greater ripening effect than TDZ. Coronatine significantly enhanced boll opening without affecting boll weight, lint percentage and seed quality. Therefore, COR can be a potential cotton defoliant with different physiological mechanism of action from the currently used TDZ. PMID:24845465

  3. Sampling strategies for square and boll-feeding plant bugs (Hemiptera: Miridae) occurring on cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six sampling methods targeting square and boll-feeding plant bugs on cotton were compared during three cotton growth periods (early-season squaring, early bloom, and peak through late bloom) by samplers differing in experience (with prior years of sampling experience or no experience) along the coas...

  4. Boll distribution and plant architecture of 14 commercial cultivars under five different irrigation regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a pressing need to identify and understand the effects of different irrigation regimes on the boll distribution, seed cotton yield, and plant architecture of commercial cultivars of cotton (Gossypium spp.). To identify the impact of different irrigation levels on the Texas High Plains 14 co...

  5. Complete genome sequence of a Klebsiella pneumoniae strain isolated from a known cotton insect boll vector

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Klebsiella pneumoniae (associated with bacterial pneumonia) was previously isolated from Nezara viridula, a significant vector of cotton boll-rot pathogens. We provide the first annotated genome sequence of the cotton opportunistic strain K. pneumoniae 5-1. This data provides guidance to study the...

  6. The phytotoxin coronatine induces abscission-related gene expression and boll ripening during defoliation of cotton.

    PubMed

    Du, Mingwei; Li, Yi; Tian, Xiaoli; Duan, Liusheng; Zhang, Mingcai; Tan, Weiming; Xu, Dongyong; Li, Zhaohu

    2014-01-01

    Defoliants can increase machine harvest efficiency of cotton (Gossypium hirusutum L.), prevent lodging and reduce the time from defoliation to harvest. Coronatine (COR) is a chlorosis-inducing non-host-specific phytotoxin that induces leaf and/or fruit abscission in some crops. The present study investigates how COR might induce cotton leaf abscission by modulating genes involved in cell wall hydrolases and ACC (ethylene precursor) in various cotton tissues. The effects of COR on cotton boll ripening, seedcotton yield, and seed development were also studied. After 14 d of treatment with COR, cells within the leaf abscission zone (AZ) showed marked differentiation. Elevated transcripts of GhCEL1, GhPG and GhACS were observed in the AZs treated with COR and Thidiazuron (TDZ). The relative expression of GhCEL1 and GhACS in TDZ treated plants was approximately twice that in plants treated with COR for 12 h. However, only GhACS expression increased in leaf blade and petiole. There was a continuous increase in the activity of hydrolytic enzymes such as cellulase (CEL) and polygalacturonase (PG), and ACC accumulation in AZs following COR and TDZ treatments, but there was greater increase in ACC activity of COR treated boll crust, indicating that COR had greater ripening effect than TDZ. Coronatine significantly enhanced boll opening without affecting boll weight, lint percentage and seed quality. Therefore, COR can be a potential cotton defoliant with different physiological mechanism of action from the currently used TDZ.

  7. Infectivity of Steinernema carpocapsae and S. feltiae to larvae and adults of the hazelnut weevil, Curculio nucum: Differential virulence and entry routes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hazel nut weevil, Curculio nucum, is a major pest of hazel nuts, particularly in Europe; hazel nut weevil is also closely related to other nut-attacking weevils such as pecan weevil (Curculio caryae). In this study, the basis for differential susceptibility of the hazelnut weevil (to entomopatho...

  8. Relationship between potassium fertilization and nitrogen metabolism in the leaf subtending the cotton (Gossypium hirsutum L.) boll during the boll development stage.

    PubMed

    Hu, Wei; Zhao, Wenqing; Yang, Jiashuo; Oosterhuis, Derrick M; Loka, Dimitra A; Zhou, Zhiguo

    2016-04-01

    The nitrogen (N) metabolism of the leaf subtending the cotton boll (LSCB) was studied with two cotton (Gossypium hirsutum L.) cultivars (Simian 3, low-K tolerant; Siza 3, low-K sensitive) under three levels of potassium (K) fertilization (K0: 0 g K2O plant(-1), K1: 4.5 K2O plant(-1) and K2: 9.0 g K2O plant(-1)). The results showed that total dry matter increased by 13.1-27.4% and 11.2-18.5% under K supply for Simian 3 and Siza 3. Boll biomass and boll weight also increased significantly in K1 and K2 treatments. Leaf K content, leaf N content and nitrate (NO3(-)) content increased with increasing K rates, and leaf N content or NO3(-) content had a significant positive correlation with leaf K content. Free amino acid content increased in the K0 treatment for both cultivars, due to increased protein degradation caused by higher protease and peptidase activities, resulting in lower protein content in the K0 treatment. The critical leaf K content for free amino acid and soluble protein content were 14 mg g(-1) and 15 mg g(-1) in Simian 3, and 17 mg g(-1) and 18 mg g(-1) in Siza 3, respectively. Nitrate reductase (NR), glutamic-oxaloace transaminase (GOT) and glutamic-pyruvic transaminase (GPT) activities increased in the K1 and K2 treatments for both cultivars, while glutamine synthetase (GS) and glutamate synthase (GOGAT) activities increased under K supply treatments only for Siza 3, and were not affected in Simian 3, indicating that this was the primary difference in nitrogen-metabolizing enzymes activities for the two cultivars with different sensitivity to low-K. PMID:26874296

  9. Relationship between potassium fertilization and nitrogen metabolism in the leaf subtending the cotton (Gossypium hirsutum L.) boll during the boll development stage.

    PubMed

    Hu, Wei; Zhao, Wenqing; Yang, Jiashuo; Oosterhuis, Derrick M; Loka, Dimitra A; Zhou, Zhiguo

    2016-04-01

    The nitrogen (N) metabolism of the leaf subtending the cotton boll (LSCB) was studied with two cotton (Gossypium hirsutum L.) cultivars (Simian 3, low-K tolerant; Siza 3, low-K sensitive) under three levels of potassium (K) fertilization (K0: 0 g K2O plant(-1), K1: 4.5 K2O plant(-1) and K2: 9.0 g K2O plant(-1)). The results showed that total dry matter increased by 13.1-27.4% and 11.2-18.5% under K supply for Simian 3 and Siza 3. Boll biomass and boll weight also increased significantly in K1 and K2 treatments. Leaf K content, leaf N content and nitrate (NO3(-)) content increased with increasing K rates, and leaf N content or NO3(-) content had a significant positive correlation with leaf K content. Free amino acid content increased in the K0 treatment for both cultivars, due to increased protein degradation caused by higher protease and peptidase activities, resulting in lower protein content in the K0 treatment. The critical leaf K content for free amino acid and soluble protein content were 14 mg g(-1) and 15 mg g(-1) in Simian 3, and 17 mg g(-1) and 18 mg g(-1) in Siza 3, respectively. Nitrate reductase (NR), glutamic-oxaloace transaminase (GOT) and glutamic-pyruvic transaminase (GPT) activities increased in the K1 and K2 treatments for both cultivars, while glutamine synthetase (GS) and glutamate synthase (GOGAT) activities increased under K supply treatments only for Siza 3, and were not affected in Simian 3, indicating that this was the primary difference in nitrogen-metabolizing enzymes activities for the two cultivars with different sensitivity to low-K.

  10. Farming of a defensive fungal mutualist by an attelabid weevil.

    PubMed

    Wang, Lin; Feng, Yu; Tian, Jianqing; Xiang, Meichun; Sun, Jingzu; Ding, Jianqing; Yin, Wen-Bing; Stadler, Marc; Che, Yongsheng; Liu, Xingzhong

    2015-08-01

    The mutualism between fungus-growing animals and fungi is a classic example of a complex interspecies association. A handful of insects, notably the well-recognized fungus-farming ants, termites and beetles, have developed advanced agriculture, which includes seeding new gardens with crop propagules, improving growth conditions and protecting and harvesting the fungal crop. More examples, which could be called 'proto-fungiculture', involve fewer adaptations, as exemplified by marine snails that farm intertidal fungi on marsh grass. Recent work has indicated that the solitary leaf-rolling weevil Euops chinensis (family Attelabidae) has a protofarming symbiosis with the mycangial fungus Penicillium herquei (family Trichocomaceae). In this study, we investigated how the weevils create cradles (leaf-rolls) for their offspring and protect the fungal garden. We describe new specialized structures and behaviors that E. chinensis females use for leaf-rolling and fungus inoculation. The fungus P. herquei produces the antibiotic (+)-scleroderolide in laboratory culture and in leaf-rolls, which can serve to inhibit microbial 'weeds' and pests, thus protecting the fungal garden against potential infection. The fungiculture of E. chinensis differs from other advanced insect fungiculture systems because female weevils do not continuously tend the inoculated microbe and do not depend nutritionally on the fungus. The defensive role of the cultivated fungus makes the attelabid weevils exceptional in 'proto-fungiculture' animals.

  11. Effect of radio frequency treatments on cowpea weevil adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dried pulses (chickpeas, lentils and dried peas) are valuable export commodities in the US Pacific Northwest. Postharvest infestation by stored product insect pests such as the cowpea weevil may cause importing countries to require phytosanitary treatments before shipment. Typically, chemical fumiga...

  12. Farming of a defensive fungal mutualist by an attelabid weevil.

    PubMed

    Wang, Lin; Feng, Yu; Tian, Jianqing; Xiang, Meichun; Sun, Jingzu; Ding, Jianqing; Yin, Wen-Bing; Stadler, Marc; Che, Yongsheng; Liu, Xingzhong

    2015-08-01

    The mutualism between fungus-growing animals and fungi is a classic example of a complex interspecies association. A handful of insects, notably the well-recognized fungus-farming ants, termites and beetles, have developed advanced agriculture, which includes seeding new gardens with crop propagules, improving growth conditions and protecting and harvesting the fungal crop. More examples, which could be called 'proto-fungiculture', involve fewer adaptations, as exemplified by marine snails that farm intertidal fungi on marsh grass. Recent work has indicated that the solitary leaf-rolling weevil Euops chinensis (family Attelabidae) has a protofarming symbiosis with the mycangial fungus Penicillium herquei (family Trichocomaceae). In this study, we investigated how the weevils create cradles (leaf-rolls) for their offspring and protect the fungal garden. We describe new specialized structures and behaviors that E. chinensis females use for leaf-rolling and fungus inoculation. The fungus P. herquei produces the antibiotic (+)-scleroderolide in laboratory culture and in leaf-rolls, which can serve to inhibit microbial 'weeds' and pests, thus protecting the fungal garden against potential infection. The fungiculture of E. chinensis differs from other advanced insect fungiculture systems because female weevils do not continuously tend the inoculated microbe and do not depend nutritionally on the fungus. The defensive role of the cultivated fungus makes the attelabid weevils exceptional in 'proto-fungiculture' animals. PMID:25658054

  13. Transgenic Cotton Plants Expressing Cry1Ia12 Toxin Confer Resistance to Fall Armyworm (Spodoptera frugiperda) and Cotton Boll Weevil (Anthonomus grandis)

    PubMed Central

    de Oliveira, Raquel S.; Oliveira-Neto, Osmundo B.; Moura, Hudson F. N.; de Macedo, Leonardo L. P.; Arraes, Fabrício B. M.; Lucena, Wagner A.; Lourenço-Tessutti, Isabela T.; de Deus Barbosa, Aulus A.; da Silva, Maria C. M.; Grossi-de-Sa, Maria F.

    2016-01-01

    Gossypium hirsutum (commercial cooton) is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique) using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter. The T0 transgenic cotton plants were initially selected with kanamycin and posteriorly characterized by PCR and Southern blot experiments to confirm the genetic transformation. Western blot and ELISA assays indicated the transgenic cotton plants with higher Cry1Ia12 protein expression levels to be further tested in the control of two major G. hirsutum insect pests. Bioassays with T1 plants revealed the Cry1Ia12 protein toxicity on Spodoptera frugiperda larvae, as evidenced by mortality up to 40% and a significant delay in the development of the target insects compared to untransformed controls (up to 30-fold). Also, an important reduction of Anthonomus grandis emerging adults (up to 60%) was observed when the insect larvae were fed on T1 floral buds. All the larvae and adult insect survivors on the transgenic lines were weaker and significantly smaller compared to the non-transformed plants. Therefore, this study provides GM cotton plant with simultaneous resistance against the Lepidopteran (S. frugiperda), and the Coleopteran (A. grandis) insect orders, and all data suggested that the Cry1Ia12 toxin could effectively enhance the cotton transgenic plants resistance to both insect pests. PMID:26925081

  14. Transgenic Cotton Plants Expressing Cry1Ia12 Toxin Confer Resistance to Fall Armyworm (Spodoptera frugiperda) and Cotton Boll Weevil (Anthonomus grandis).

    PubMed

    de Oliveira, Raquel S; Oliveira-Neto, Osmundo B; Moura, Hudson F N; de Macedo, Leonardo L P; Arraes, Fabrício B M; Lucena, Wagner A; Lourenço-Tessutti, Isabela T; de Deus Barbosa, Aulus A; da Silva, Maria C M; Grossi-de-Sa, Maria F

    2016-01-01

    Gossypium hirsutum (commercial cooton) is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique) using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter. The T0 transgenic cotton plants were initially selected with kanamycin and posteriorly characterized by PCR and Southern blot experiments to confirm the genetic transformation. Western blot and ELISA assays indicated the transgenic cotton plants with higher Cry1Ia12 protein expression levels to be further tested in the control of two major G. hirsutum insect pests. Bioassays with T1 plants revealed the Cry1Ia12 protein toxicity on Spodoptera frugiperda larvae, as evidenced by mortality up to 40% and a significant delay in the development of the target insects compared to untransformed controls (up to 30-fold). Also, an important reduction of Anthonomus grandis emerging adults (up to 60%) was observed when the insect larvae were fed on T1 floral buds. All the larvae and adult insect survivors on the transgenic lines were weaker and significantly smaller compared to the non-transformed plants. Therefore, this study provides GM cotton plant with simultaneous resistance against the Lepidopteran (S. frugiperda), and the Coleopteran (A. grandis) insect orders, and all data suggested that the Cry1Ia12 toxin could effectively enhance the cotton transgenic plants resistance to both insect pests. PMID:26925081

  15. Control of Cowpea Weevil, Callosobruchus Maculatus (F.) (Coleoptera: Bruchidae), Using Natural Plant Products.

    PubMed

    Tiroesele, Bamphitlhi; Thomas, Kesegofetse; Seketeme, Seipati

    2014-12-31

    A laboratory study was conducted to investigate the effects of natural products on the reproduction and damage of Callosobruchus maculatus, the cowpea weevil, on cowpea seeds at Botswana College of Agriculture in Gaborone, Botswana. The cowpea variety Blackeye was used in the study. Fifty grams of each plant product (garlic, peppermint and chilies) was added to 500 g of the cowpea seeds. Findings of this experiment revealed that chilies and garlic had negative effects on cowpea weevils for all parameters measured. Peppermint also showed significant reduction in the F₁ progeny of the cowpea weevils but with less effect on weevils than garlic and chilies. The results indicate that these plant products have the potential to protect cowpea seeds from cowpea weevils' damage compared to when the seeds are left or stored unprotected. They should, therefore, be included in pest management strategies for cowpea weevil in grains stored on-farm in rural tropical and subtropical regions.

  16. Study on weevil pests of oilseed rape at Keszthely, Hungary.

    PubMed

    Marczali, Zs; Keszthelyi, S; Nádasy, M; Budai, P; Lehoczky, E

    2010-01-01

    One of the most important pests of rape in early spring are weevils (Ceutorhynchus spp.). The aim of our studies was to identify the occurring weevil species and to study their emergence, swarming, mating and damage. Our observations were performed on an experimental plot at Keszthely (Hungary, Zala County) in early spring of four consecutive years. Following species were collected and identified: Ceutorhynchus pallidactylus MARSHAM, Ceutorhynchus obstrictus MARSHAM, Ceutorhynchus napi GYLLENHAL, Ceutorhynchus pleurostigma MARSHAM. The obvious dominance of C. pallidactylus and C. obstrictus was detected. Their frequency of occurrence was 88-90% among the identified adults. We found that C. obstrictus was the last species to settle. Complete developmental period was 68 +/- 7 days in case of C. pallidactylus and 70 +/- 7 days in case of C. obstrictus. Average number of eggs laid by one female was 176 +/- 23 in case of C. obstrictus and 21 +/- 6 in case of C. pallidactylus.

  17. Brilliant camouflage: photonic crystals in the diamond weevil, Entimus imperialis

    PubMed Central

    Wilts, Bodo D.; Michielsen, Kristel; Kuipers, Jeroen; De Raedt, Hans; Stavenga, Doekele G.

    2012-01-01

    The neotropical diamond weevil, Entimus imperialis, is marked by rows of brilliant spots on the overall black elytra. The spots are concave pits with intricate patterns of structural-coloured scales, consisting of large domains of three-dimensional photonic crystals that have a diamond-type structure. Reflectance spectra measured from individual scale domains perfectly match model spectra, calculated with anatomical data and finite-difference time-domain methods. The reflections of single domains are extremely directional (observed with a point source less than 5°), but the special arrangement of the scales in the concave pits significantly broadens the angular distribution of the reflections. The resulting virtually angle-independent green coloration of the weevil closely approximates the colour of a foliaceous background. While the close-distance colourful shininess of E. imperialis may facilitate intersexual recognition, the diffuse green reflectance of the elytra when seen at long-distance provides cryptic camouflage. PMID:22378806

  18. Relationship between carrot weevil infestation and parsley yield.

    PubMed

    Torres, Angel N; Hoy, Casey W

    2005-08-01

    The relationship between numbers of carrot weevil, Listronotus oregonensis (LeConte), oviposition scars and parsley fresh weight and plant mortality was measured in research plots during 1999 and 2000. Fresh weight was measured in one to two cuttings of parsley planted on two planting dates. The average weight declined with increasing numbers of oviposition scars in the later planting in 1999. Compensatory growth in surviving plants may reduce this effect. Plant mortality increased as number of oviposition scars per plant increased in the second planting in both years and in the first cutting of the first planting in 2000. One oviposition scar per plant is sufficient to result in significant reduction in fresh weight per plant. In commercial parsley fields, the relationship between fresh weight of parsley per 30-cm row section of parsley was best described as a linear function of the proportion of plants with root feeding. Economic damage to parsley that is equivalent to the cost of controlling carrot weevil was estimated to result from approximately 1% of plants with root damage. Based upon this estimated economic injury level, we suggest an action threshold of 1% of plants containing carrot weevil oviposition scars earlier in the growing season when controls could be applied to prevent the damage.

  19. Phototactic Behavior of the Armand Pine Bark Weevil, Pissodes punctatus

    PubMed Central

    Chen, You; Luo, Chang W.; Kuang, Rong P.; Li, Hong W.; Chen, Zheng; Liu, Ying J.

    2013-01-01

    The Armand pine bark weevil, Pissodes punctatus Langor et Zhang (Coleoptera: Curculionidae) is a destructive bark weevil on the Armand pine, Pinus armandii Franch (Pinales: Pinaceae), an important timbering tree in southern China. This study examined the phototactic behavior ïéP. punctatus through observation of behavioral characteristics, response to nine monochromatic lights (ranging from 340 nm to 689 nm with about 40-nm step), and response to five intensities (ranging from 1 lux to 200 lux) of the most attractive light. The results demonstrated that P. punctatus was most active in the day, and kept still at night (or in a dark room). P. punctatus could be attracted to eight of nine monochromatic lights, the exception being red light (649 nm), which implied broad sensitivity to the spectrum of light. P. punctatus was most sensitive to violet (415 nm), ultraviolet (340 nm), and green (504 nm) light, suggesting there might be at least three types of photoreceptors in the compound eyes of this weevil. Furthermore, low intensities elicited an increased phototactic response, and high intensities a decreased phototactic response, under both violet and UV light. Thus, P. punctatus were found to be phototactic insects, and the phototactic behavior of P. punctatus is both a color and intensity preference. The information provided here provides a basis for the improvement of trapping devices for detection and survey of P. punctatus, as well as a basis for the development of alternate control strategies for this important pest of Armand pine and other pine trees. PMID:23879189

  20. Phenylphenalenones Accumulate in Plant Tissues of Two Banana Cultivars in Response to Herbivory by the Banana Weevil and Banana Stem Weevil.

    PubMed

    Hölscher, Dirk; Buerkert, Andreas; Schneider, Bernd

    2016-01-01

    Phenylphenalenone-type compounds accumulated in the tissues of two banana cultivars-Musa acuminata cv. "Grande Naine" (AAA) and Musa acuminata × balbisiana Colla cv. "Bluggoe" (ABB)-when these were fed on by the banana weevil (Cosmopolites sordidus (Germ.) (Coleoptera: Curculionidae)) and the banana stem weevil (Odoiporus longicollis (Oliver) (Coleoptera: Curculionidae)). The chemical constituents of the banana material were separated by means of chromatographic techniques and identified by NMR spectroscopy. One new compound, 2-methoxy-4-phenylphenalen-1-one, was found exclusively in the corm material of "Bluggoe" that had been fed on by the weevils. PMID:27571112

  1. Phenylphenalenones Accumulate in Plant Tissues of Two Banana Cultivars in Response to Herbivory by the Banana Weevil and Banana Stem Weevil

    PubMed Central

    Hölscher, Dirk; Buerkert, Andreas; Schneider, Bernd

    2016-01-01

    Phenylphenalenone-type compounds accumulated in the tissues of two banana cultivars—Musa acuminata cv. “Grande Naine” (AAA) and Musa acuminata × balbisiana Colla cv. “Bluggoe” (ABB)—when these were fed on by the banana weevil (Cosmopolites sordidus (Germ.) (Coleoptera: Curculionidae)) and the banana stem weevil (Odoiporus longicollis (Oliver) (Coleoptera: Curculionidae)). The chemical constituents of the banana material were separated by means of chromatographic techniques and identified by NMR spectroscopy. One new compound, 2-methoxy-4-phenylphenalen-1-one, was found exclusively in the corm material of “Bluggoe” that had been fed on by the weevils. PMID:27571112

  2. Phenylphenalenones Accumulate in Plant Tissues of Two Banana Cultivars in Response to Herbivory by the Banana Weevil and Banana Stem Weevil.

    PubMed

    Hölscher, Dirk; Buerkert, Andreas; Schneider, Bernd

    2016-08-25

    Phenylphenalenone-type compounds accumulated in the tissues of two banana cultivars-Musa acuminata cv. "Grande Naine" (AAA) and Musa acuminata × balbisiana Colla cv. "Bluggoe" (ABB)-when these were fed on by the banana weevil (Cosmopolites sordidus (Germ.) (Coleoptera: Curculionidae)) and the banana stem weevil (Odoiporus longicollis (Oliver) (Coleoptera: Curculionidae)). The chemical constituents of the banana material were separated by means of chromatographic techniques and identified by NMR spectroscopy. One new compound, 2-methoxy-4-phenylphenalen-1-one, was found exclusively in the corm material of "Bluggoe" that had been fed on by the weevils.

  3. Olfactory responses of banana weevil predators to volatiles from banana pseudostem tissue and synthetic pheromone.

    PubMed

    Tinzaara, W; Gold, C S; Dicke, M; van Huis, A

    2005-07-01

    As a response to attack by herbivores, plants can emit a variety of volatile substances that attract natural enemies of these insect pests. Predators of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) such as Dactylosternum abdominale (Coleoptera: Hydrophilidae) and Pheidole megacephala (Hymenoptera: Formicidae), are normally found in association with weevil-infested rotten pseudostems and harvested stumps. We investigated whether these predators are attracted to such environments in response to volatiles produced by the host plant, by the weevil, or by the weevil plant complex. We evaluated predator responses towards volatiles from banana pseudostem tissue (synomones) and the synthetic banana weevil aggregation pheromone Cosmolure+ in a two-choice olfactometer. The beetle D. abdominale was attracted to fermenting banana pseudostem tissue and Cosmolure+, whereas the ant P. megacephala was attracted only to fermented pseudostem tissue. Both predators were attracted to banana pseudostem tissue that had been damaged by weevil larvae irrespective of weevil presence. Adding pheromone did not enhance predator response to volatiles from pseudostem tissue fed on by weevils. The numbers of both predators recovered with pseudostem traps in the field from banana mats with a pheromone trap were similar to those in pseudostem traps at different distance ranges from the pheromone. Our study shows that the generalist predators D. abdominale and P. megacephala use volatiles from fermented banana pseudostem tissue as the major chemical cue when searching for prey. PMID:16222791

  4. Polygalacturonase from Sitophilus oryzae: Possible horizontal transfer of a pectinase gene from fungi to weevils

    PubMed Central

    Shen, Zhicheng; Denton, Michael; Mutti, Navdeep; Pappan, Kirk; Kanost, Michael R.; Reese, John C.; Reeck, Gerald R.

    2003-01-01

    Endo-polygalacturonase, one of the group of enzymes known collectively as pectinases, is widely distributed in bacteria, plants and fungi. The enzyme has also been found in several weevil species and a few other insects, such as aphids, but not in Drosophila melanogaster, Anopheles gambiae, or Caenorhabditis elegans or, as far as is known, in any more primitive animal species. What, then, is the genetic origin of the polygalacturonases in weevils? Since some weevil species harbor symbiotic microorganisms, it has been suggested, reasonably, that the symbionts' genomes of both aphids and weevils, rather than the insects' genomes, could encode polygalacturonase. We report here the cloning of a cDNA that encodes endo-polygalacturonase in the rice weevil, Sitophilus oryzae (L.), and investigations based on the cloned cDNA. Our results, which include analysis of genes in antibiotic-treated rice weevils, indicate that the enzyme is, in fact, encoded by the insect genome. Given the apparent absence of the gene in much of the rest of the animal kingdom, it is therefore likely that the rice weevil polygalacturonase gene was incorporated into the weevil's genome by horizontal transfer, possibly from a fungus. PMID:15841240

  5. Molecular systematics and evolution in an African cycad-weevil interaction: Amorphocerini (Coleoptera: Curculionidae: Molytinae) weevils on Encephalartos.

    PubMed

    Downie, D A; Donaldson, J S; Oberprieler, R G

    2008-04-01

    Weevils in the tribe Amorphocerini have been implicated in pollination of Encephalartos species in southern Africa. The services they render these plants and the unique attributes of the cycad-weevil interaction make them important from both conservation and evolutionary standpoints. Oberprieler [Oberprieler, R.G., 1996. Systematics and evolution of the tribe Amorphocerini, with a review of the cycad weevils of the world. Ph.D. dissertation, University of the Free State, Bloemfontein, South Africa], using morphological characters, proposed a tentative hypothesis of relationships among the Amorphocerini which is tested here using DNA sequence data. Sequences from one mitochondrial and three nuclear genes were used to infer phylogenetic relationships, levels of sequence divergence, evolution of host associations, and patterns of speciation in this tribe. The results are reasonably consistent with the morphological hypothesis of relationships and species concepts, though important differences are observed, particularly in relationships among a Porthetes hispidus Boheman species group, which is indicated to have experienced recent divergences. In general, low levels of sequence divergence among species within two of the three genera indicate a recent radiation of this tribe onto African cycads, thus while cycad-insect interactions have often been considered ancient this may not be the case for some extant interactions. A complex pattern of host shifts onto both closely related and more distantly related hosts is suggested. PMID:18328737

  6. Control of Cowpea Weevil, Callosobruchus Maculatus (F.) (Coleoptera: Bruchidae), Using Natural Plant Products

    PubMed Central

    Tiroesele, Bamphitlhi; Thomas, Kesegofetse; Seketeme, Seipati

    2014-01-01

    A laboratory study was conducted to investigate the effects of natural products on the reproduction and damage of Callosobruchus maculatus, the cowpea weevil, on cowpea seeds at Botswana College of Agriculture in Gaborone, Botswana. The cowpea variety Blackeye was used in the study. Fifty grams of each plant product (garlic, peppermint and chilies) was added to 500 g of the cowpea seeds. Findings of this experiment revealed that chilies and garlic had negative effects on cowpea weevils for all parameters measured. Peppermint also showed significant reduction in the F1 progeny of the cowpea weevils but with less effect on weevils than garlic and chilies. The results indicate that these plant products have the potential to protect cowpea seeds from cowpea weevils’ damage compared to when the seeds are left or stored unprotected. They should, therefore, be included in pest management strategies for cowpea weevil in grains stored on-farm in rural tropical and subtropical regions. PMID:26463066

  7. Endosymbiotic candidates for parasitoid defense in exotic and native New Zealand weevils.

    PubMed

    White, Jennifer A; Richards, Nicola K; Laugraud, Aurelie; Saeed, Abiya; Curry, Meghan M; McNeill, Mark R

    2015-07-01

    Some insects are infected with maternally inherited bacterial endosymbionts that protect them against pathogens or parasitoids. The weevil Sitona obsoletus (=Sitona lepidus) is invasive in New Zealand, and suspected to contain such defensive symbionts, because it is particularly resistant to a Moroccan strain of the parasitoid Microctonus aethiopoides (which successfully attacks many other weevil species), and shows geographic variation in susceptibility to an Irish strain of the same parasitoid. Using 454 pyrosequencing, we investigated the bacterial community associated with S. obsoletus, two other exotic weevils (Sitona discoideus and Listronotus bonariensis) and two endemic New Zealand weevils (Irenimus aequalis and Steriphus variabilis). We found that S. obsoletus was infected by one strain of Wolbachia and two strains of Rickettsia, none of which were found in any other weevil species examined. Using diagnostic PCR, we found that S. obsoletus in the Northland region, where parasitism is highly variable, were primarily infected with Wolbachia and Rickettsia strain 2, indicating that these two symbionts should be investigated for potential defensive properties. In comparison, S. discoideus lacked any apparent maternally inherited bacterial endosymbionts. In the other weevil species, we found a different strain of Wolbachia and two different strains of Spiroplasma. Two weevil species (St. variabilis and L. bonariensis) were infected with distinct strains of Nardonella, the ancestral endosymbiont of weevils, whereas three weevil species (S. obsoletus, S. discoideus, and I. aequalis) lacked evidence for Nardonella infection. However, I. aequalis was consistently infected with a novel Enterobacteriaceae strain, suggesting that a symbiont replacement may have taken place, similar to that described for other weevil clades.

  8. Cotton (Gossypium hirsutum L.) boll rotting bacteria vectored by the brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidea)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determine the capacity of the brown stink bug (Euschistus servus) to transmit an infective Pantoea agglomerans into cotton (Gossypium hirsutum, L.) bolls. A laboratory colony of the brown stink bug (BSB) was maintained on fresh green beans. The P. agglomerans mutant strain Sc 1-R that holds rifamp...

  9. Exploring high throughput phenotyping, plant architecture and plant-boll distribution for improving drought tolerance in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a pressing need to identify and understand the effects of different irrigation regimes on plant-boll distribution, seed cotton yield, and plant architecture for improving yield and fiber quality under stress and/or drought tolerance of cotton (Gossypium spp.) cultivars. To identify the impa...

  10. Influence of tillage on adult and immature pea leaf weevil (Coleoptera: Curculionidae) densities in pea.

    PubMed

    Hanavan, Ryan P; Bosque-Pérez, Nilsa A; Schotzko, Dennis J; Eigenbrode, Sanford D

    2010-06-01

    The pea leaf weevil, Sitona lineatus (L.) (Coleoptera: Curculionidae), has been a major pest of pea, Pisum sativum L., in eastern Washington and northern Idaho since its introduction to the region in the early 1970s. Eggs are deposited in the spring on the soil surface and first instars hatch and move to pea root nodules, where larvae feed before they pupate and adults emerge in mid- to late summer. No-tillage practices are known to reduce pea leaf weevil colonization in pea, but the effects of tillage on larval densities and subsequent adult emergence have not been examined. During 2005, 2006, and 2007, we compared densities of colonizing adult and immature pea leaf weevils on pea plots grown using conventional tillage and no-tillage. In 2005 and 2006, emergence of adult pea leaf weevil was monitored in the same plots. Densities of colonizing adult and immature pea leaf weevil were significantly higher in conventional tillage plots. Larvae in conventional tillage were further along in development than larvae in no-tillage plots during June and July. Densities of emerging adult pea leaf weevil were significantly greater from conventional tillage than no-tillage plots. Based on densities of colonizing and subsequent emerging adults, survival of weevils from egg through adult was greater in conventional tillage plots. Soils under no-tillage are cooler, resulting in later emergence of the pea crop and delayed root nodule development, possibly affecting the ability of first-instar pea leaf weevil to locate host plant roots. Our results indicate no-tillage fields are less suitable for pea leaf weevil colonization and survival than conventional tillage fields.

  11. [Biological characteristics of the egg phase of citrus root weevils].

    PubMed

    Guedes, Jerson V C; Parra, José R P

    2007-01-01

    The goal of this work was to study some characteristics of the egg phase of three species of citrus root weevils. The insects were collected from citrus plants in Itapetininga, SP, and brought to the Laboratório de Biologia de Insetos of ESALQ/USP, in Piracicaba, SP, where the species Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) and Parapantomorus fluctuosus (Boheman) were kept. Duration and viability of the egg phase were evaluated, and the lower temperature threshold and thermal constant (K) were calculated for these species. The species of citrus root weevils showed different duration of egg phases. The egg phase ranged from 40.4 to 13.8 N. cervinus, from 38.7 to 20.0 days for N. versatilis, and from 35.0 to 13.8 days for P. fluctuosus, depending upon temperature. The temperature thresholds of this stage were 8.1, 8.3, and 9.9 masculineC at thermal constant was 385.7, 397.7 and 294.1 degree-days, for N. cervinus, N. versatilis and P. fluctuosus respectively. The duration of the egg phases of N. cervinus and N. versatilis were similar at the same temperatures and P. fluctuosus had a faster development than Naupactus spp. in all temperatures tested.

  12. Pleiotropic impact of endosymbiont load and co-occurrence in the maize weevil Sitophilus zeamais.

    PubMed

    Carvalho, Gislaine A; Vieira, Juliana L; Haro, Marcelo M; Corrêa, Alberto S; Ribon, Andrea Oliveira B; de Oliveira, Luiz Orlando; Guedes, Raul Narciso C

    2014-01-01

    Individual traits vary among and within populations, and the co-occurrence of different endosymbiont species within a host may take place under varying endosymbiont loads in each individual host. This makes the recognition of the potential impact of such endosymbiont associations in insect species difficult, particularly in insect pest species. The maize weevil, Sitophilus zeamais Motsch. (Coleoptera: Curculionidae), a key pest species of stored cereal grains, exhibits associations with two endosymbiotic bacteria: the obligatory endosymbiont SZPE ("Sitophilus zeamais Primary Endosymbiont") and the facultative endosymbiont Wolbachia. The impact of the lack of SZPE in maize weevil physiology is the impairment of nutrient acquisition and energy metabolism, while Wolbachia is an important factor in reproductive incompatibility. However, the role of endosymbiont load and co-occurrence in insect behavior, grain consumption, body mass and subsequent reproductive factors has not yet been explored. Here we report on the impacts of co-occurrence and varying endosymbiont loads achieved via thermal treatment and antibiotic provision via ingested water in the maize weevil. SZPE exhibited strong effects on respiration rate, grain consumption and weevil body mass, with observed effects on weevil behavior, particularly flight activity, and potential consequences for the management of this pest species. Wolbachia directly favored weevil fertility and exhibited only mild indirect effects, usually enhancing the SZPE effect. SZPE suppression delayed weevil emergence, which reduced the insect population growth rate, and the thermal inactivation of both symbionts prevented insect reproduction. Such findings are likely important for strain divergences reported in the maize weevil and their control, aspects still deserving future attention. PMID:25347417

  13. Chemodiversity and biodiversity of fungi associated with the pine weevil Hylobius abietis.

    PubMed

    Azeem, Muhammad; Terenius, Olle; Rajarao, Gunaratna Kuttuva; Nagahama, Kazuhiro; Nordenhem, Henrik; Nordlander, Göran; Borg-Karlson, Anna-Karin

    2015-08-01

    The pine weevil Hylobius abietis is a severe pest of conifer seedlings in reforestation areas. Weevils lay eggs in the root bark or in the soil near roots of recently dead trees and cover the eggs with frass (feces combined with chewed bark), possibly to avoid conspecific egg predation. The aim of the present investigation focused on isolation, identification, and volatile production of fungi from pine-weevil feces and frass. Fungi were isolated from weevil frass and feces separately, followed by identification based on ITS sequencing. Fifty-nine isolates belonging to the genera Penicillium, Ophiostoma, Mucor, Leptographium, Eucasphaeria, Rhizosphaera, Debaryomyces, and Candida were identified. Volatile organic compounds (VOCs) produced by the fungal community and fungal isolates cultured on weevil-frass broth were identified by SPME-GCMS. Major VOCs emitted from the fungal community and pure isolates were species- and strain specific and included isopentylalcohol, styrene, 3-octanone, 6-protoilludene, methyl salicylate, 3-methylanisole, 2-methoxyphenol, and phenol. Some of these are known to influence the orientation of pine weevils when tested among highly attractive newly planted conifer seedlings.

  14. Chemodiversity and biodiversity of fungi associated with the pine weevil Hylobius abietis.

    PubMed

    Azeem, Muhammad; Terenius, Olle; Rajarao, Gunaratna Kuttuva; Nagahama, Kazuhiro; Nordenhem, Henrik; Nordlander, Göran; Borg-Karlson, Anna-Karin

    2015-08-01

    The pine weevil Hylobius abietis is a severe pest of conifer seedlings in reforestation areas. Weevils lay eggs in the root bark or in the soil near roots of recently dead trees and cover the eggs with frass (feces combined with chewed bark), possibly to avoid conspecific egg predation. The aim of the present investigation focused on isolation, identification, and volatile production of fungi from pine-weevil feces and frass. Fungi were isolated from weevil frass and feces separately, followed by identification based on ITS sequencing. Fifty-nine isolates belonging to the genera Penicillium, Ophiostoma, Mucor, Leptographium, Eucasphaeria, Rhizosphaera, Debaryomyces, and Candida were identified. Volatile organic compounds (VOCs) produced by the fungal community and fungal isolates cultured on weevil-frass broth were identified by SPME-GCMS. Major VOCs emitted from the fungal community and pure isolates were species- and strain specific and included isopentylalcohol, styrene, 3-octanone, 6-protoilludene, methyl salicylate, 3-methylanisole, 2-methoxyphenol, and phenol. Some of these are known to influence the orientation of pine weevils when tested among highly attractive newly planted conifer seedlings. PMID:26228562

  15. Response of successive three generations of cotton bollworm, Helicoverpa armigera (Hübner), fed on cotton bolls under elevated CO2.

    PubMed

    Wu, Gang; Chen, Fa-jun; Sun, Yu-cheng; Ge, Feng

    2007-01-01

    The growth, development and consumption of successive three generations of cotton bollworm, Helicoverpa armigera (Hübner), fed on cotton bolls grown under elevated CO2 (double-ambient vs. ambient) in open-top chambers were examined. Significant decreases in protein, total amino acid, water and nitrogen content and increases in free fatty acid were observed in cotton bolls. Changes in quality of cotton bolls affected the growth, development and food utilization of H. armigera. Significantly longer larval development duration in three successive generations and lower pupal weight of the second and third generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower fecundity was also found in successive three generations of H. armigera fed on cotton bolls grown under elevated CO2. The consumption per larva occurred significant increase in successive three generations and frass per larva were also significantly increased during the second and third generations under elevated CO2. Significantly lower relative growth rate, efficiency of conversion of ingested food and significant higher relative consumption rate in successive three generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower potential female fecundity, larval numbers and population consumption were found in the second and third generations of cotton bollworm fed on cotton bolls grown under elevated CO2. The integrative effect of higher larval mortality rate and lower adult fecundity resulted in significant decreases in potential population consumption in the latter two generations. The results show that elevated CO2 adversely affects cotton bolls quality, which indicates the potential population dynamics and potential population consumption of cotton bollworm will alleviate the harm to the plants in the future rising CO2 atmosphere. PMID:18232225

  16. Toxigenic Aspergillus and Penicillium Isolates from Weevil-Damaged Chestnuts

    PubMed Central

    Wells, John M.; Payne, Jerry A.

    1975-01-01

    Aspergillus and Penicillium were among the most common genera of fungi isolated on malt-salt agar from weevil-damaged Chinese chestnut kernels (16.8 and 40.7% occurrence, respectively). Chloroform extracts of 21 of 50 Aspergillus isolates and 18 of 50 representative Penicillium isolates, grown for 4 weeks at 21.1 C on artificial medium, were toxic to day-old cockerels. Twelve of the toxic Aspergillus isolates were identified as A. wentii, eight as A. flavus, and one as A. flavus var. columnaris. Nine of the toxic Penicillium isolates were identified as P. terrestre, three as P. steckii, two each as P. citrinum and P. funiculosum, and one each as P. herquei (Series) and P. roqueforti (Series). Acute diarrhea was associated with the toxicity of A. wentii and muscular tremors with the toxicity of P. terrestre, one isolate of P. steckii, and one of P. funiculosum. PMID:1190758

  17. Annotated catalogue of Australian weevils  (Coleoptera: Curculionoidea).

    PubMed

    Pullen, Kimberi R; Jennings, Debbie; Oberprieler, Rolf G

    2014-01-01

    This catalogue presents the first-ever complete inventory of all described taxa of Australian weevils, including both valid and invalid names. The geographical scope spans mainland Australia and its continental islands as well as the subantarctic Heard and McDonald Islands, the Pacific Lord Howe and Norfolk Islands and the Indian-Ocean Christmas Island. 4111 species in 832 genera (including one extinct species and one fossil) are recognised as occurring in this territory, distributed over seven families, 20 subfamilies and 94 tribes. The families and subfamilies are arranged in a currently accepted phylogenetic sequence but the tribes, genera and species in alphabetical order. Introductory chapters outline the discovery and composition of the Australian weevil fauna, the burden of synonymy, the format and conventions of the catalogue and the taxonomic and nomenclatural changes proposed. Sixteen new genera and six new species are described, two new names and 25 new generic and 72 new species synonymies and 189 new combinations are proposed and 46 type species designations are effected. The records of 356 taxa are annotated to justify or explain various taxonomic and nomenclatural acts and issues, covering descriptions of new taxa, new synonymies and generic combinations, artificial taxon concepts, changes in classification and a number of nomenclatural matters. The catalogue of the taxa present in Australia is followed by a list of 19 species incorrectly recorded from Australia or introduced as biocontrol agents but not established, and by one species inquirenda. All these records are also annotated. Two appendices list the 102 species introduced into Australia, both accidental and deliberate (as weed control agents). A bibliography with full references of all original descriptions and pertinent other citations from the literature is provided, and an index to all names concludes the catalogue.

  18. Genetic analysis of Upland cotton dynamic heterosis for boll number per plant at multiple developmental stages

    PubMed Central

    Shang, Lianguang; Wang, Yumei; Cai, Shihu; Ma, Lingling; Liu, Fang; Chen, Zhiwen; Su, Ying; Wang, Kunbo; Hua, Jinping

    2016-01-01

    Yield is an important breeding target. As important yield components, boll number per plant (BNP) shows dynamic character and strong heterosis in Upland cotton. However, the genetic basis underlying the dynamic heterosis is poorly understood. In this study, we conducted dynamic quantitative trait loci (QTL) analysis for BNP and heterosis at multiple developmental stages and environments using two recombinant inbred lines (RILs) and two corresponding backcross populations. By the single-locus analysis, 23 QTLs were identified at final maturity, while 99 QTLs were identified across other three developmental stages. A total of 48 conditional QTLs for BNP were identified for the adjacent stages. QTLs detected at later stage mainly existed in the partial dominance to dominance range and QTLs identified at early stage mostly showed effects with the dominance to overdominance range during plant development. By two-locus analysis, we observe that epistasis played an important role not only in the variation of the performance of the RIL population but also in the expression of heterosis in backcross population. Taken together, the present study reveals that the genetic basis of heterosis is dynamic and complicated, and it is involved in dynamic dominance effect, epistasis and QTL by environmental interactions. PMID:27748451

  19. Artificial substrates for oviposition and larval development of the pepper weevil (Coleoptera: Curculionidae).

    PubMed

    Addesso, K M; McAuslane, H J; Stansly, P A; Slansky, F; Schuster, D J

    2009-02-01

    The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is a major pest of cultivated peppers (Capsicum spp.) and other cultivated and wild species within the family Solanaceae. Laboratory study of this insect, as well as its biological control agents, will be greatly facilitated by an artificial rearing system that does not rely on pepper fruit. An egg collection method and amendments to a standard larval diet were investigated for use in the rearing of this weevil. Spherical sachets made of Parafilm or netting enclosing leaves of pepper, American black nightshade, eggplant, tomato, potato, and jasmine tobacco induced oviposition. Tomato, potato, and jasmine tobacco leaves were accepted despite the fact that these are not oviposition hosts for pepper weevils in the wild. A standard larval diet formula was modified in an attempt to improve egg hatch, larval survival, developmental time, and adult mass. The diet formula was modified with the addition of freeze-dried jalapeño pepper powder, an additional lipid source, alternate protein sources, and the removal of methyl paraben. None of the aforementioned treatments resulted in a significant improvement over the standard diet. Egg hatch was greater when eggs were incubated on moist paper towels rather than in diet; thus, placement of neonates rather than eggs into diet improved production of adults. Suggestions for more efficient rearing of weevils on the currently available diet and future directions for the development of an artificial rearing system for pepper weevil are discussed. PMID:19253644

  20. Pea weevil damage and chemical characteristics of pea cultivars determining their resistance to Bruchus pisorum L.

    PubMed

    Nikolova, I

    2016-04-01

    Bruchus pisorum (L.) is one of the most intractable pest problems of cultivated pea in Europe. Development of resistant cultivars is very important to environmental protection and would solve this problem to a great extent. Therefore, the resistance of five spring pea cultivars was studied to B. pisorum: Glyans, Modus; Kamerton and Svit and Pleven 4 based on the weevil damage and chemical composition of seeds. The seeds were classified as three types: healthy seeds (type one), damaged seeds with parasitoid emergence holes (type two) and damaged seeds with bruchid emergence holes (type three). From visibly damaged pea seeds by pea weevil B. pisorum was isolated the parasitoid Triaspis thoracica Curtis (Hymenoptera, Braconidae). Modus, followed by Glyans was outlined as resistant cultivars against the pea weevil. They had the lowest total damaged seed degree, loss in weight of damaged seeds (type two and type three) and values of susceptibility coefficients. A strong negative relationship (r = -0.838) between the weight of type one seeds and the proportion of type three seeds was found. Cultivars with lower protein and phosphorus (P) content had a lower level of damage. The crude protein, crude fiber and P content in damaged seeds significantly or no significantly were increased as compared with the healthy seeds due to weevil damage. The P content had the highest significant influence on pea weevil infestation. Use of chemical markers for resistance to the creation of new pea cultivars can be effective method for defense and control against B. pisorum. PMID:26837535

  1. Herbivore pressure by weevils associated with flower color polymorphism in Geranium thunbergii (Geraniaceae).

    PubMed

    Tsuchimatsu, Takashi; Yoshitake, Hiraku; Ito, Motomi

    2014-03-01

    Although floral herbivory has recently received increased attention as an important factor influencing plant reproduction, relatively little is known about how its frequency and intensity vary depending on traits of host plants. Here we report that herbivore pressure by a weevil, Zacladus geranii, is associated with a flower color polymorphism of Geranium thunbergii (Geraniaceae). Pink and white flower color morphs have been reported in G. thunbergii, and we found in a three-year field survey in multiple populations that, generally, adult weevils more preferentially visited white flowers than pink flowers. Consistently, we found more severe damage by weevil larvae in white flowers. Overall herbivore pressure for G. thunbergii varied strongly between populations, and the difference seems to be partly explained by the co-occurrence of a related plant species, Geranium yezoense, in a population, as weevils preferred it to both color morphs of G. thunbergii, thereby relaxing overall herbivore pressure for G. thunbergii. Nonetheless, despite such high variability, the preference of weevils for white morphs over pink morphs of G. thunbergii was found across multiple populations. We discuss possible mechanisms causing the association between flower color and herbivore preference as well as its evolutionary consequences. PMID:24253757

  2. Artificial substrates for oviposition and larval development of the pepper weevil (Coleoptera: Curculionidae).

    PubMed

    Addesso, K M; McAuslane, H J; Stansly, P A; Slansky, F; Schuster, D J

    2009-02-01

    The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is a major pest of cultivated peppers (Capsicum spp.) and other cultivated and wild species within the family Solanaceae. Laboratory study of this insect, as well as its biological control agents, will be greatly facilitated by an artificial rearing system that does not rely on pepper fruit. An egg collection method and amendments to a standard larval diet were investigated for use in the rearing of this weevil. Spherical sachets made of Parafilm or netting enclosing leaves of pepper, American black nightshade, eggplant, tomato, potato, and jasmine tobacco induced oviposition. Tomato, potato, and jasmine tobacco leaves were accepted despite the fact that these are not oviposition hosts for pepper weevils in the wild. A standard larval diet formula was modified in an attempt to improve egg hatch, larval survival, developmental time, and adult mass. The diet formula was modified with the addition of freeze-dried jalapeño pepper powder, an additional lipid source, alternate protein sources, and the removal of methyl paraben. None of the aforementioned treatments resulted in a significant improvement over the standard diet. Egg hatch was greater when eggs were incubated on moist paper towels rather than in diet; thus, placement of neonates rather than eggs into diet improved production of adults. Suggestions for more efficient rearing of weevils on the currently available diet and future directions for the development of an artificial rearing system for pepper weevil are discussed.

  3. Factors Affecting Pheromone Production by the Pepper Weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) and Collection Efficiency

    PubMed Central

    Eller, Fred J.; Palmquist, Debra E.

    2014-01-01

    Several factors affecting pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae) as well as collection efficiency were investigated. Factors studied included: porous polymer adsorbents (Tenax versus Super Q), male age, time of day, male density, and male diet. Super Q was found to be a superior adsorbent for the male-produced alcohols and geranic acid as well as the plant-produced E-β-ocimene. Pheromone production increased with male age up to about age 15 days old and then tapered off. Male pepper weevils produced the highest amount of pheromone between noon and 2 pm (i.e., 4 to 6 h after “lights on”) and were producing ca. 800 ng/h during this period. Thereafter, pheromone production decreased and was extremely low during the scotophase (i.e., ca. 12 ng/h). Male pepper weevil density had a significant effect on both release rate and pheromone composition. Pheromone production on a per male basis was highest for individual males and the percentage of geranic acid in the blend was lowest for individual males. Male pepper weevils produced only extremely low amounts of pheromone when feeding on artificial diet; however, they produced very high amounts when on fresh peppers. Together, this information will be useful in designing better attractant lures for pepper weevils. PMID:26462948

  4. [Effects of nitrogen fertilization rate and planting density on cotton boll biomass and nitrogen accumulation in extremely early maturing cotton region of Northeast China].

    PubMed

    Wang, Zi-Sheng; Wu, Xiao-Dong; Gao, Xiang-Bin; Xu, Min; Shen, Dan; Jin, Lu-Lu; Zhou, Zhi-Guo

    2012-02-01

    Taking cotton cultivars Liaomian 19 and NuCoTN 33B as test materials, a field experiment was conducted to study the effects of nitrogen fertilization rate (0, 240 and 480 kg x hm(-2)) and planting density (75000, 97500 and 120000 plants x hm(-2)) on the boll biomass and nitrogen accumulation in the extremely early maturing cotton region of Northeast China. With the growth and development of cotton, the biomass and nitrogen accumulation of cotton boll, cotton seed, and cotton fiber varied in 'S' shape. Both nitrogen fertilization rate and planting density had significant effects on the dynamic characteristics of boll biomass and nitrogen accumulation, and on the fiber yield and quality. In treatment 240 kg x hm(-2) and 97500 plants x hm(-2), the biomass of single boll, cotton seed and cotton fiber was the maximum, the starting time and ending time of the rapid accumulation period of the biomass and nitrogen were earlier but the duration of the accumulation was shorter, the rapid accumulation speed of the biomass was the maximum, and the distribution indices of the biomass and nitrogen were the lowest in boll shell but the highest in cotton seed and cotton fiber.

  5. Efficacy of aggregation pheromone in trapping red palm weevil (Rhynchophorus ferrugineus Olivier) and rhinoceros beetle (Oryctes rhinoceros Linn.) from infested coconut palms.

    PubMed

    Chakravarthy, A K; Chandrashekharaiah, M; Kandakoor, Subhash B; Nagaraj, D N

    2014-05-01

    Red palm weevil and Rhinoceros beetle are the major pests inflicting severe damage to coconut palms. Due to ineffectiveness of the current management practices to control the two important pests on coconut, a study was conducted to know the attractiveness of red palm weevil and rhinoceros beetle to aggregation pheromone. Olfactometer studies indicated that the aggregation pheromone of red palm weevil and rhinoceros beetle attracted significantly more number of weevils (13.4 females and 7.6 male weevils) and beetles (6.5 male and 12.3 female beetles), respectively than control. Similarly, field studies found that both 750 and 1000 mg pheromone dosage lures of red palm weevil and rhinoceros beetle trapped significantly higher numbers of weevils (695.80 and 789 weevils, respectively) and beetles (98 and 108 beetles, respectively) in traps (P < 0.05), respectively. On an average (n = 6 field trials) 80-85% red palm weevil and 72-78% rhinoceros beetle population got trapped. Observations indicated activity of red palm weevil throughout the year and of rhinoceros beetle from September to March around Bangalore, South India. Pheromone traps for red palm weevil can be placed in fields from June to August and October to December and September to February for rhinoceros beetle. Population reductions of the two coleopteran pests by pheromone traps are compatible with mechanical and cultural management tools with cumulative effects.

  6. Efficacy of aggregation pheromone in trapping red palm weevil (Rhynchophorus ferrugineus Olivier) and rhinoceros beetle (Oryctes rhinoceros Linn.) from infested coconut palms.

    PubMed

    Chakravarthy, A K; Chandrashekharaiah, M; Kandakoor, Subhash B; Nagaraj, D N

    2014-05-01

    Red palm weevil and Rhinoceros beetle are the major pests inflicting severe damage to coconut palms. Due to ineffectiveness of the current management practices to control the two important pests on coconut, a study was conducted to know the attractiveness of red palm weevil and rhinoceros beetle to aggregation pheromone. Olfactometer studies indicated that the aggregation pheromone of red palm weevil and rhinoceros beetle attracted significantly more number of weevils (13.4 females and 7.6 male weevils) and beetles (6.5 male and 12.3 female beetles), respectively than control. Similarly, field studies found that both 750 and 1000 mg pheromone dosage lures of red palm weevil and rhinoceros beetle trapped significantly higher numbers of weevils (695.80 and 789 weevils, respectively) and beetles (98 and 108 beetles, respectively) in traps (P < 0.05), respectively. On an average (n = 6 field trials) 80-85% red palm weevil and 72-78% rhinoceros beetle population got trapped. Observations indicated activity of red palm weevil throughout the year and of rhinoceros beetle from September to March around Bangalore, South India. Pheromone traps for red palm weevil can be placed in fields from June to August and October to December and September to February for rhinoceros beetle. Population reductions of the two coleopteran pests by pheromone traps are compatible with mechanical and cultural management tools with cumulative effects. PMID:24813002

  7. Classification of weevils as a data-driven science: leaving opinion behind.

    PubMed

    Jordal, Bjarte H; Smith, Sarah M; Cognato, Anthony I

    2014-01-01

    Data and explicit taxonomic ranking criteria, which minimize taxonomic change, provide a scientific approach to modern taxonomy and classification. However, traditional practices of opinion-based taxonomy (i.e., mid-20(th) century evolutionary systematics), which lack explicit ranking and naming criteria, are still in practice despite phylogenetic evidence. This paper discusses a recent proposed reclassification of weevils that elevates bark and ambrosia beetles (Scolytinae and Platypodinae) to the ranks of Family. We demonstrate that the proposed reclassification 1) is not supported by an evolutionary systematic justification because the apparently unique morphology of bark and ambrosia beetles is shared with other unrelated wood-boring weevil taxa; 2) introduces obvious paraphyly in weevil classification and hence violates good practices on maintaining an economy of taxonomic change; 3) is not supported by other taxonomic naming criteria, such as time banding. We recommend the abandonment of traditional practices of an opinion-based taxonomy, especially in light of available data and resulting phylogenies.

  8. Additive photonic colors in the Brazilian diamond weevil: entimus imperialis

    NASA Astrophysics Data System (ADS)

    Mouchet, S.; Vigneron, J.-P.; Colomer, J.-F.; Vandenbem, C.; Deparis, O.

    2012-10-01

    Structurally colored nano-architectures found in living organisms are complex optical materials, giving rise to multiscale visual effects. In arthropods, these structures often consist of porous biopolymers and form natural photonic crystals. A signature of the structural origin of coloration in insects is iridescence, i.e., color changes with the viewing angle. In the scales located on the elytra of the Brazilian weevil Entimus imperialis (Curculionidae), three-dimensional photonic crystals are observed. On one hand, each of them interacts independently with light, producing a single color which is observed by optical microscopy and ranges from blue to orange. On the other hand, the color perceived by the naked eye is due to multi-length-scale light effects involving different orientations of a single photonic crystal. This disorder in crystal orientations alters the light propagation in such a way that the crystal iridescence is removed. Entimus imperialis is therefore a remarkable example of additive photonic colors produced by a complex multi-scale organic architecture. In order to study this specific natural photonic structure, electron microscopy is used. The structure turns out to be formed of a single type of photonic crystal with different orientations within each scale on the elytra. Our modeling approach takes into account the disorder in the photonic crystals and explains why the structure displays bright colors at the level of individual scales and a non-iridescent green color in the far-field.

  9. Dispersal of Warren root collar weevils (Coleoptera: Curculionidae) in three types of habitat.

    PubMed

    Machial, Laura A; Lindgren, B Staffan; Steenweg, Robin W; Aukema, Brian H

    2012-06-01

    Warren root collar weevil, Hylobius warreni Wood, is a native, flightless insect distributed throughout the boreal forest of North America. It is an emerging problem in young plantings of lodgepole pine, Pinus contorta variety latifolia, in western Canada, where larval feeding can kill young trees by girdling the root collar. Susceptible plantings are becoming more abundant following salvage harvesting and replanting activities in the wake of an ongoing epidemic of mountain pine beetle, Dendroctonus ponderosae (Hopkins). Previous studies using mark-trap-recapture methods found that movement rates of adult H. warreni were elevated in areas with high numbers of dead trees, consistent with a hypothesis that the insects immigrate from stands with high mountain pine beetle-caused tree mortality to young plantings in search of live hosts. Sampling methods were necessarily biased to insects captured in traps; however, potentially missing individuals that had died, left the study area, or simply remained stationary. Here, we used harmonic radar to examine weevil movement in three different habitats: open field, forest edge, and within a forest. We were able to reliably monitor all but two of 36 insects initially released, over 96 h (4 d). Weevils released in the open field had the highest rates of movement, followed by weevils released at the forest edge, then weevils released within the forest. Movement declined with decreasing ambient air temperature. Our results suggest that weevils tend to be relatively stationary in areas of live hosts, and hence may concentrate in a suitable area once such habitat is found. PMID:22732616

  10. How Far Can the Palm Weevil, Rhynchophorus vulneratus (Coleoptera: Curculionidae), Fly?

    PubMed

    Hoddle, M S; Hoddle, C D

    2016-04-01

    The palm weevil, Rhynchophorus vulneratus, is native to Southeast Asia and was recovered from an infested Canary Islands date palm in Laguna Beach, California, USA, in 2010. The detection of this potentially destructive palm pest initiated a detection, containment, and eradication program that was reliant, in part, on the deployment of bucket traps loaded with aggregation pheromone and baited with fermenting fruit. A key question that pertained to the deployment of traps was “how far can R. vulneratus fly?” This question could not be answered and in response to this knowledge deficit, computerized flight mill studies were conducted with field-captured R. vulneratus in an outdoor screen house in Sumatra, Indonesia. Of the 63 weevils tethered to flight mills, ∼27% failed to fly >1 km in 24 h and were excluded from analyses. In total, 46 weevils (35 females and 11 males) flew >1 km on flight mills and of these adults, the average total distance flown in 24 h was significantly greater for females (∼32 km) when compared with males (∼15 km). A small proportion of females (∼16%) flew 50-80 km, and one female flew 100.1 km in 24 h. Flying weevils exhibited an average weight loss of ∼13–17% and non-flying control weevils (n=27) lost 10–13% body weight in 24 h. The distribution of flight distances for female and male weevils combined was leptokurtic, which suggests that faster than expected spread by R. vulneratus may be possible in invaded areas. PMID:26791820

  11. Sampling strategies for square and boll-feeding plant bugs (Hemiptera: Miridae) occurring on cotton.

    PubMed

    Brewer, Michael J; Anderson, Darwin J; Armstrong, J Scott; Villanueva, Raul T

    2012-06-01

    Sampling methods for square and boll-feeding plant bugs (Hemiptera: Miridae) occurring on cotton, Gossypium hirsutum L., were compared with the intent to assess if one approach was viable for two species occurring from early-season squaring to late bloom in 25 fields located along the coastal cotton growing region of south Texas. Cotton fleaphopper, Pseudatomoscelis seriatus (Reuter), damages squares early-season and dominated collections using five sampling methods (approximately 99% of insects collected). A major species composition shift occurred beginning at peak bloom in coastal fields, when verde plant bug, Creontiades signatus Distant, represented 55-65% of collections. Significantly more cotton fleahoppers were captured by experienced samplers with the beat bucket and sweep net than with the other methods (30-100% more). There were more than twice as many verde plant bugs captured by experienced and inexperienced samplers with the beat bucket and sweep net than captured with the KISS and visual methods. Using a beat bucket or sweep net reduced sampling time compared with the visual method for the experienced samplers. For both species, comparing regressions of beat bucket-based counts to counts from the traditional visual method across nine cultivar and water regime combinations resulted in only one combination differing from the rest, suggesting broad applicability and ability to translate established visual-based economic thresholds to beat bucket-based thresholds. In a first look at sample size considerations, 40 plants (four 10-plant samples) per field site was no more variable than variation associated with larger sample sizes. Overall, the beat bucket is much more effective in sampling for cotton fleahopper and verde plant bug than the traditional visual method, it is more suited to cotton fleahopper sampling early-season when plants are small, it transitions well to sample for verde plant bug during bloom, and it performs well under a variety of soil

  12. Sampling strategies for square and boll-feeding plant bugs (Hemiptera: Miridae) occurring on cotton.

    PubMed

    Brewer, Michael J; Anderson, Darwin J; Armstrong, J Scott; Villanueva, Raul T

    2012-06-01

    Sampling methods for square and boll-feeding plant bugs (Hemiptera: Miridae) occurring on cotton, Gossypium hirsutum L., were compared with the intent to assess if one approach was viable for two species occurring from early-season squaring to late bloom in 25 fields located along the coastal cotton growing region of south Texas. Cotton fleaphopper, Pseudatomoscelis seriatus (Reuter), damages squares early-season and dominated collections using five sampling methods (approximately 99% of insects collected). A major species composition shift occurred beginning at peak bloom in coastal fields, when verde plant bug, Creontiades signatus Distant, represented 55-65% of collections. Significantly more cotton fleahoppers were captured by experienced samplers with the beat bucket and sweep net than with the other methods (30-100% more). There were more than twice as many verde plant bugs captured by experienced and inexperienced samplers with the beat bucket and sweep net than captured with the KISS and visual methods. Using a beat bucket or sweep net reduced sampling time compared with the visual method for the experienced samplers. For both species, comparing regressions of beat bucket-based counts to counts from the traditional visual method across nine cultivar and water regime combinations resulted in only one combination differing from the rest, suggesting broad applicability and ability to translate established visual-based economic thresholds to beat bucket-based thresholds. In a first look at sample size considerations, 40 plants (four 10-plant samples) per field site was no more variable than variation associated with larger sample sizes. Overall, the beat bucket is much more effective in sampling for cotton fleahopper and verde plant bug than the traditional visual method, it is more suited to cotton fleahopper sampling early-season when plants are small, it transitions well to sample for verde plant bug during bloom, and it performs well under a variety of soil

  13. Effects of combining microbial and chemical insecticides on mortality of the pecan weevil (Coleoptera: Curculionidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecans [Carya illinoinensis (Wangenh.) K. Koch]. Current control recommendations are based on chemical insecticide applications, primarily carbaryl and pyrethroids (e.g., cypermethrin). Microbial control agents such as the entomopathogenic...

  14. Green light synergistally enhances male sweetpotato weevil response to sex pheromone.

    PubMed

    McQuate, Grant T

    2014-01-01

    Sweetpotato, commercially grown in over 100 countries, is one of the ten most important staple crops in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter tasting and toxic sesquiterpenes which can render the sweetpotato unfit for consumption. A significant step towards improved management of this weevil species was the identification of a female-produced sex pheromone [(Z)-3-dodecenyl (E)-2-butenoate] to which males are highly attracted. Reported here are results of research that documents a nearly 5-fold increase in male sweetpotato weevil catch in traps baited with this pheromone and a green light provided by a solar-powered, light-emitting diode (LED). The combination of olfactory and night-visible visual cues significantly enhanced trap effectiveness for this nighttime-active insect species. These results provide promise for improved sweetpotato weevil detection and suppression in mass trapping programs. PMID:24675727

  15. Green Light Synergistally Enhances Male Sweetpotato Weevil Response to Sex Pheromone

    PubMed Central

    McQuate, Grant T.

    2014-01-01

    Sweetpotato, commercially grown in over 100 countries, is one of the ten most important staple crops in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter tasting and toxic sesquiterpenes which can render the sweetpotato unfit for consumption. A significant step towards improved management of this weevil species was the identification of a female-produced sex pheromone [(Z)-3-dodecenyl (E)-2-butenoate] to which males are highly attracted. Reported here are results of research that documents a nearly 5-fold increase in male sweetpotato weevil catch in traps baited with this pheromone and a green light provided by a solar-powered, light-emitting diode (LED). The combination of olfactory and night-visible visual cues significantly enhanced trap effectiveness for this nighttime-active insect species. These results provide promise for improved sweetpotato weevil detection and suppression in mass trapping programs. PMID:24675727

  16. Characterization of Microsatellite Loci in Smicronyx Sodidus, the Gray Sunflower Seed Weevil (Coleoptera: Curculionidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The gray sunflower seed weevil (GSSW) Smicronyx sordidus, native to North America, is one of the major seed pests of cultivated sunflowers in the Central and Northern Great Plains. The larvae of GSSW feed on the kernels of the sunflower seeds, and may cause severe damage to this economically importa...

  17. Relationship of black vine weevil egg density and damage to two cranberry cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field and laboratory trials compared Metarhizium anisopliae and Steinernema kraussei to imidacloprid for black vine weevil (BVW), Otiorhynchus sulcatus, larval control in cranberry. Two field sites were treated in fall of 2009 and soil samples collected during 2009 and 2010 to assess treatment effic...

  18. Phylogeography of specialist weevil Trichobaris soror: a seed predator of Datura stramonium.

    PubMed

    De-la-Mora, Marisol; Piñero, Daniel; Núñez-Farfán, Juan

    2015-12-01

    Can the genetic structure of a specialist weevil be explained by the geological history of their distribution zone? We analyze the genetic variation of the weevil Trichobaris soror, a specialist seed predator of Datura stramonium, in order to address this question. For the phylogeographic analysis we used the COI gene, and assessed species identity in weevil populations through geometric morphometric approach. In total, we found 53 haplotypes in 413 samples, whose genetic variation supports the formation of three groups: (1) the Transmexican Volcanic Belt (TVB group), (2) the Sierra Madre Sur (SMS group) and (3) the Balsas Basin (BB group). The morphometric analysis suggests that BB group is probably not T. soror. Our results have two implications: first, the phylogeographic pattern of T. soror is explained by both the formation of the geological provinces where it is currently distributed and the coevolution with its host plant, because the TVB and SMS groups could be separated due to the discontinuity of altitude between the geological provinces, but the recent population expansion of TVB group and the high frequency of only one haplotype can be due to specialization to the host plant. Second, we report a new record of a different species of weevil in BB group parasitizing D. stramonium fruits. PMID:26498017

  19. Bean alpha-amylase inhibitors in transgenic peas inhibit development of pea weevil larvae.

    PubMed

    de Sousa-Majer, Maria José; Hardie, Darryl C; Turner, Neil C; Higgins, Thomas J V

    2007-08-01

    This glasshouse study used an improved larval measurement procedure to evaluate the impact of transgenic pea, Pisum sativum L., seeds expressing a-amylase inhibitor (AI)-1 or -2 proteins on pea weevil, Bruchus pisorum L. Seeds of transgenic 'Laura' and 'Greenfeast' peas expressing alpha-(AI)-1 reduced pea weevil survival by 93-98%. Larval mortality occurred at an early instar. Conversely, in nontransgenic cultivars, approximately 98-99% of the pea weevils emerged as adults. By measuring the head capsule size, we determined that larvae died at the first to early third instar in alpha-(AI)-1 transgenic peas, indicating that this inhibitor is highly effective in controlling this insect. By contrast, transgenic Laura and 'Dundale' expressing alpha-(AI)-2 did not affect pea weevil survival, but they did delay larval development. After 77 d of development, the head capsule size indicated that the larvae were still at the third instar stage in transgenic alpha-(AI)-2 peas, whereas adult bruchids had developed in the nontransgenic peas.

  20. Phylogeography of specialist weevil Trichobaris soror: a seed predator of Datura stramonium.

    PubMed

    De-la-Mora, Marisol; Piñero, Daniel; Núñez-Farfán, Juan

    2015-12-01

    Can the genetic structure of a specialist weevil be explained by the geological history of their distribution zone? We analyze the genetic variation of the weevil Trichobaris soror, a specialist seed predator of Datura stramonium, in order to address this question. For the phylogeographic analysis we used the COI gene, and assessed species identity in weevil populations through geometric morphometric approach. In total, we found 53 haplotypes in 413 samples, whose genetic variation supports the formation of three groups: (1) the Transmexican Volcanic Belt (TVB group), (2) the Sierra Madre Sur (SMS group) and (3) the Balsas Basin (BB group). The morphometric analysis suggests that BB group is probably not T. soror. Our results have two implications: first, the phylogeographic pattern of T. soror is explained by both the formation of the geological provinces where it is currently distributed and the coevolution with its host plant, because the TVB and SMS groups could be separated due to the discontinuity of altitude between the geological provinces, but the recent population expansion of TVB group and the high frequency of only one haplotype can be due to specialization to the host plant. Second, we report a new record of a different species of weevil in BB group parasitizing D. stramonium fruits.

  1. Effects of combining microbial and chemical insecticides on mortality of the Pecan Weevil (Coleoptera: Curculionidae).

    PubMed

    Shapiro-Ilan, David I; Cottrell, Ted E; Wood, Bruce W

    2011-02-01

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan [Carya illinoinensis (Wangenh.) K. Koch]. Current control recommendations are based on chemical insecticide applications. Microbial control agents such as the entomopathogenic nematode, Steinernema carpocapsae (Weiser) and the fungus Beauveria bassiana (Balsamo) Vuillemin occur naturally in southeastern U.S. pecan orchards and have shown promise as alternative control agents for C. caryjae. Conceivably, the chemical and microbial agents occur simultaneously within pecan orchards or might be applied concurrently. The objective of this study was to determine the interactions between two chemical insecticides that are used in commercial C. caryae control (i.e., carbaryl and cypermethrin applied below field rates) and the microbial agents B. bassiana and S. carpocapsae. In laboratory experiments, pecan weevil larval or adult mortality was assessed after application of microbial or chemical treatments applied singly or in combination (microbial + chemical agent). The nature of interactions (antagonism, additivity, or synergy) in terms of weevil mortality was evaluated over 9 d (larvae) or 5 d (adults). Results for B. bassiana indicated synergistic activity with carbaryl and antagonism with cypermethrin in C. caryae larvae and adults. For S. carpocapsae, synergy was detected with both chemicals in C. caryae larvae, but only additive effects were detected in adult weevils. Our results indicate that the chemical-microbial combinations tested are compatible with the exception of B. bassiana and cypermethrin. In addition, combinations that exhibited synergistic interactions may provide enhanced C. caryae control in commercial field applications; thus, their potential merits further exploration. PMID:21404833

  2. New initiatives for managment of red palm weevil threats to historical Arabian date palms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The date palm is an important part of the religious, cultural, and economic heritage of the Arabian Peninsula. This heritage is threatened by the recent invasion of the red palm weevil(RPW) from Southeast Asia. In Saudi Arabia, a national campaign for control of RPW by containment/destruction of inf...

  3. Factors affecting pheromone production by the pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) and collection efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several factors which might affect pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae), were investigated. Included were a comparison of porous polymer adsorbents (Tenax versus Super Q), the effect of male age, the effect of time of day, the effect of mal...

  4. A synopsis of the orchid weevil genus Orchidophilus Buchanan (Curculionidae, Baridinae), with taxonomic rectifications and description of one new species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six species of the weevil genus Orchidophilus Buchanan are recognized: O. epidendri (Murray) comb. n. (=Acythopeus genuinus Pascoe syn. n., =Baris orchivora Blackburn syn. n., =Apotomorhinus orchidearum Kolbe syn. n.), O. aterrimus (Waterhouse), O. eburifer (Pascoe) comb. n. (=Acythopeus gilvonotatu...

  5. The Efficacy of Bacillus thuringiensis spp. galleriae Against Rice Water Weevil (Coleoptera: Curculionidae) for Integrated Pest Management in California Rice.

    PubMed

    Aghaee, Mohammad-Amir; Godfrey, Larry D

    2015-02-01

    Rice water weevil (Lissorhoptrus oryzophilus Kushel) is the most damaging insect pest of rice in the United States. Larval feeding on the roots stunt growth and reduce yield. Current pest management against the weevil in California relies heavily on pyrethroids that can be damaging to aquatic food webs. Examination of an environmentally friendly alternative biopesticide based on Bacillus thuringiensis spp. galleriae chemistry against rice water weevil larvae showed moderate levels of activity in pilot studies. We further examined the performance of different formulations of Bt.galleriae against the leading insecticide used in California rice, λ-cyhalothrin. The granular formulation performed as well as the λ-cyhalothrin in use in California in some of our greenhouse and field studies. This is the first reported use of B. thuringiensis spp. galleriae against rice water weevil.

  6. Apparent Acquired Resistance by a Weevil to Its Parasitoid Is Influenced by Host Plant

    PubMed Central

    Goldson, Stephen L.; Tomasetto, Federico

    2016-01-01

    Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel; Coleoptera: Curculionidae) by Microctonus hyperodae Loan (Hymenoptera: Braconidae) are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian Lolium multiflorum, diploid Lolium perenne and diploid hybrid L. perenne ×L. multiflorum; none of which were infected by Epichloë endophyte. At the same time, the opportunity was taken to compare the results of this study with observations made during extensive laboratory-based research and parasitoid-rearing in the 1990s using the same host plant species. This made it possible to determine whether there has been any change in weevil susceptibility to the parasitoid over a 20 year period when in the presence of the tetraploid Italian, diploid perennial and hybrid host grasses that were commonly in use in the 1990’s. The incidence of parasitism in cages, in the presence of these three grasses mirrored what has recently been observed in the field. When caged, weevil parasitism rates in the presence of a tetraploid Italian ryegrass host were significantly higher (75%) than rates that occurred in the presence of either the diploid perennial (46%) or the diploid hybrid (52%) grass, which were not significantly different from each other. This is very different to laboratory parasitism rates in the 1990s when in the presence of both of the latter grasses high rates of parasitism (c. 75%) were recorded. These high rates are typical of those still found in weevils in the presence of both field and caged tetraploid Italian grasses. In contrast, the abrupt decline in weevil parasitism rates points to the possibility of evolved resistance by the weevil to the parasitoid in the diploid and hybrid grasses, but not so in the tetraploid. The orientation of plants in the laboratory cages had no significant effect

  7. Apparent Acquired Resistance by a Weevil to Its Parasitoid Is Influenced by Host Plant.

    PubMed

    Goldson, Stephen L; Tomasetto, Federico

    2016-01-01

    Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel; Coleoptera: Curculionidae) by Microctonus hyperodae Loan (Hymenoptera: Braconidae) are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian Lolium multiflorum, diploid Lolium perenne and diploid hybrid L. perenne ×L. multiflorum; none of which were infected by Epichloë endophyte. At the same time, the opportunity was taken to compare the results of this study with observations made during extensive laboratory-based research and parasitoid-rearing in the 1990s using the same host plant species. This made it possible to determine whether there has been any change in weevil susceptibility to the parasitoid over a 20 year period when in the presence of the tetraploid Italian, diploid perennial and hybrid host grasses that were commonly in use in the 1990's. The incidence of parasitism in cages, in the presence of these three grasses mirrored what has recently been observed in the field. When caged, weevil parasitism rates in the presence of a tetraploid Italian ryegrass host were significantly higher (75%) than rates that occurred in the presence of either the diploid perennial (46%) or the diploid hybrid (52%) grass, which were not significantly different from each other. This is very different to laboratory parasitism rates in the 1990s when in the presence of both of the latter grasses high rates of parasitism (c. 75%) were recorded. These high rates are typical of those still found in weevils in the presence of both field and caged tetraploid Italian grasses. In contrast, the abrupt decline in weevil parasitism rates points to the possibility of evolved resistance by the weevil to the parasitoid in the diploid and hybrid grasses, but not so in the tetraploid. The orientation of plants in the laboratory cages had no significant effect on

  8. Apparent Acquired Resistance by a Weevil to Its Parasitoid Is Influenced by Host Plant

    PubMed Central

    Goldson, Stephen L.; Tomasetto, Federico

    2016-01-01

    Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel; Coleoptera: Curculionidae) by Microctonus hyperodae Loan (Hymenoptera: Braconidae) are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian Lolium multiflorum, diploid Lolium perenne and diploid hybrid L. perenne ×L. multiflorum; none of which were infected by Epichloë endophyte. At the same time, the opportunity was taken to compare the results of this study with observations made during extensive laboratory-based research and parasitoid-rearing in the 1990s using the same host plant species. This made it possible to determine whether there has been any change in weevil susceptibility to the parasitoid over a 20 year period when in the presence of the tetraploid Italian, diploid perennial and hybrid host grasses that were commonly in use in the 1990’s. The incidence of parasitism in cages, in the presence of these three grasses mirrored what has recently been observed in the field. When caged, weevil parasitism rates in the presence of a tetraploid Italian ryegrass host were significantly higher (75%) than rates that occurred in the presence of either the diploid perennial (46%) or the diploid hybrid (52%) grass, which were not significantly different from each other. This is very different to laboratory parasitism rates in the 1990s when in the presence of both of the latter grasses high rates of parasitism (c. 75%) were recorded. These high rates are typical of those still found in weevils in the presence of both field and caged tetraploid Italian grasses. In contrast, the abrupt decline in weevil parasitism rates points to the possibility of evolved resistance by the weevil to the parasitoid in the diploid and hybrid grasses, but not so in the tetraploid. The orientation of plants in the laboratory cages had no significant effect

  9. Comparing in-season external and internal signs of feeding caused by sucking bugs to damage at harvest, with emphasis on creontiades signatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucking bug management in cotton has increased in importance, now with less pressure from boll weevil and boll-feeding worms. Cotton along the Texas Coastal Bend experienced loss to boll-feeding sucking bugs during 2010, especially in fields near the coast. This loss was magnified due to boll rot. C...

  10. Evidence of contact pheromone use in mating behavior of the raspberry weevil (Coleoptera: Curculionidae).

    PubMed

    Mutis, Ana; Parra, Leonardo; Palma, Rubén; Pardo, Fernando; Perich, Fernando; Quiroz, Andrés

    2009-02-01

    Numerous studies of insect species have shown that a subset of female cuticular hydrocarbons is used as short-range or contact pheromones. Here, we studied the possible use of contact pheromones in the mating behavior of the weevil Aegorhinus superciliosus, a native species of Chile. Males mounted females only after antennal contact with the female's cuticle, and only 33% of the males attempted to mate with dead females washed with solvent. When a glass rod (dummy) was coated with female cuticular extracts, males exhibited behaviors similar to those observed with females. A preliminary gas chromatography-mass spectrometry (GC-MS) analysis of cuticular extracts indicated that males and females share a series of aliphatic hydrocarbons but that the relative abundance of some of these compounds differ between the sexes. These results suggest that cuticular lipids mediate mating behavior of the raspberry weevil and provide the first evidence of contact pheromones in curculionids.

  11. Predicting Developmental Timing for Immature Canada Thistle Stem-Mining Weevils, Hadroplontus litura (Coleoptera: Curculionidae).

    PubMed

    Gramig, Greta G; Burns, Erin E; Prischmann-Voldseth, Deirdre A

    2015-08-01

    Predictions of phenological development for insect biological control agents may facilitate post-release monitoring efforts by allowing land managers to optimize the timing of monitoring activities. A logistic thermal time model was tested to predict phenology of immature stem-mining weevils, Hadroplontus litura F. (Coleoptera: Curculionidae), a biological control agent for Canada thistle, Cirsium arvense L. (Asterales: Asteraceae). Weevil eggs and larvae were collected weekly from Canada thistle stems in eastern North Dakota from May through July during 2010 and 2011. Head capsule widths of sampled larvae were measured at the widest point and plotted on a frequency histogram to establish ranges of head capsule widths associated with each instar. We found head capsule width ranges for first-, second-, and third-instar H. litura larvae were 165-324 µm, 346-490 µm, and 506-736 µm, respectively. Logistic regression models were developed to estimate the proportions of H. litura eggs, first-, and second-instar larvae in the weevil population as a function of thermal time. Model estimates of median development time for eggs, first instars, and second instars ranged from 219 ± 23 degree-days (DD) to 255 ± 27 DD, 556 ± 77 DD to 595 ± 81 DD, and 595 ± 109 DD to 653 ± 108 DD, respectively. Based on model validation statistics, model estimates for development timing were the most accurate for eggs and first instars and somewhat less accurate for second instars. These model predictions will help biological control practitioners obtain more accurate estimates of weevil population densities during post-release monitoring. PMID:26314053

  12. Ethyl Formate: A Potential Disinfestation Treatment for Eucalyptus Weevil (Gonipterus platensis) (Coleoptera: Curculionidae) in Apples.

    PubMed

    Agarwal, Manjree; Ren, Yonglin; Newman, James; Learmonth, Stewart

    2015-12-01

    Export of Pink Lady apples from Australia has been significantly affected by infestations of adult eucalyptus weevils (Gonipterus platensis Marelli). These weevils cling tenaciously to the pedicel of apple fruit when selecting overwintering sites. As a result, apples infested with live G. platensis adults lead to rejection for export. Since the Montreal Protocol restricted use of methyl bromide as postharvest treatment, it was necessary to consider alternative safer fumigants for disinfestation of eucalyptus weevil. Laboratory experiments were conducted using concentrations of 5, 10, 15, 20, 25, 30, 40, and 80 mg/liter of ethyl formate. Complete control (100% mortality) was achieved at 25-30 mg/liter of ethyl formate at 22-24°C for 24-h exposure without apples. However, with 90-95% of the volume full of apples, complete control was achieved at 40 mg/liter of ethyl formate at 22-24°C for 24-h exposure. No phytotoxicity was observed and after one day aeration, residue of ethyl formate declined to natural levels (0.05-0.2 mg/kg). Five ethyl formate field trials were conducted in cool storages (capacity from 250-900 tons) and 100% kill of eucalyptus weevils were achieved at 50-55 mg/liter at 7-10°C for 24 h. Ethyl formate has great potential for preshipment treatment of apples. Its use is considerably cheaper and safer than already existing fumigants like methyl bromide and phosphine.

  13. Olfactory Cues Are Subordinate to Visual Stimuli in a Neotropical Generalist Weevil

    PubMed Central

    Otálora-Luna, Fernando; Lapointe, Stephen L.; Dickens, Joseph C.

    2013-01-01

    The tropical root weevil Diaprepes abbreviatus is a major pest of multiple crops in the Caribbean Islands and has become a serious constraint to citrus production in the United States. Recent work has identified host and conspecific volatiles that mediate host- and mate-finding by D. abbreviatus. The interaction of light, color, and odors has not been studied in this species. The responses of male and female D. abbreviatus to narrow bandwidths of visible light emitted by LEDs offered alone and in combination with olfactory stimuli were studied in a specially-designed multiple choice arena combined with a locomotion compensator. Weevils were more attracted to wavelengths close to green and yellow compared with blue or ultraviolet, but preferred red and darkness over green. Additionally, dim green light was preferred over brighter green. Adult weevils were also attracted to the odor of its citrus host + conspecifics. However, the attractiveness of citrus + conspecific odors disappeared in the presence of a green light. Photic stimulation induced males but not females to increase their speed. In the presence of light emitted by LEDs, turning speed decreased and path straightness increased, indicating that weevils tended to walk less tortuously. Diaprepes abbreviatus showed a hierarchy between chemo- and photo-taxis in the series of experiments presented herein, where the presence of the green light abolished upwind anemotaxis elicited by the pheromone + host plant odor. Insight into the strong responses to visual stimuli of chemically stimulated insects may be provided when the amount of information supplied by vision and olfaction is compared, as the information transmission capacity of compound eyes is estimated to be several orders of magnitude higher compared with the olfactory system. Subordination of olfactory responses by photic stimuli should be considered in the design of strategies aimed at management of such insects. PMID:23341926

  14. Biological Control of the Pecan Weevil, Curculio caryae (Coleoptera: Curculionidae), with Entomopathogenic Nematodes

    PubMed Central

    Smith, M. T.; Georgis, R.; Nyczepir, A. P.; Miller, R. W.

    1993-01-01

    Steinernema carpocapsae (Weiser) strain A11, S. feltiae (Filipjev) strain SN, and Heterorhabditis bacteriophora Poinar strains HP88 and Georgia were tested for their efficacy as biological control agents of the pecan weevil, Curculio caryae (Horn), in pecan orchard soil-profile containers under greenhouse conditions. Percentage C. caryae parasitism by S. carpocapsae and H. bacteriophora strain HP88 and Georgia was consistently poor when applied either prior to or following C. caryae entry into the soil, suggesting that these nematode species and (or) their enterobacteria are poor biological control agents of weevil larvae. Soil taken 21 days following application of S. carpocapsae or H. bacteriophora strain HP88 induced a low rate of infection of Galleria mellonella larvae, whereas soil that had been similarily treated with H. bacteriophora strain Georgia induced a moderate rate of infection. Percentage C. caryae parasitism by S. feltiae was consistently low when applied following C. caryae entry into the soil and was inconsistent when applied as a barrier prior to entry of weevil larvae into the soil. Soil taken 21 days following application of S. feltiae induced a high rate of infection of G. mellonella larvae. PMID:19279746

  15. Greenhouse studies of thiamethoxam effects on pea leaf weevil, Sitona lineatus.

    PubMed

    Cárcamo, Héctor; Herle, Carolyn; Hervet, Vincent

    2012-01-01

    The pea leaf weevil, Sitona lineatus L. (Coleoptera: Curculionidae), has recently emerged as an important pest of field peas in the Canadian prairies. Systemic seed-coated insecticides may provide a tool for the integrated pest management of this pest. Therefore, several controlled assays were performed in order to determine effects of a recently registered neonicotinoid, (thiamethoxam) on S. lineatus damage to foliage, weevil mortality, fertility, egg viability, larval mortality, and root nodule damage. Foliage damage was reduced by thiamethoxam relative to untreated controls during the seedling stage (2(nd)-5(th) nodes), but weevil adult mortality was only 15-30%. Fertility was reduced substantially through an extra seven-day delay in the preoviposition period and reduced egg-laying rate during the first 20 days of the study (92% lower than controls). Overall egg viability was lower in females fed foliage grown from thiamethoxamtreated seeds. Larval survivorship and nodule damage were also lower, but only when eggs were added to treated plants at the 2(nd) node stage. When eggs were added late, at the 5th node stage, thiamethoxam had no effect on larval survivorship or nodule damage. The results of this study led to the conclusion that seed treatments such as thiamethoxam have potential to be used as tools that will aid in the integrated pest management of S. lineatus, especially in combination with other methods such as biocontrol and trap crops. PMID:23461362

  16. Chemical evaluation of African palm weevil, Rhychophorus phoenicis, larvae as a food source.

    PubMed

    Elemo, Babajide O; Elemo, Gloria N; Makinde, M A; Erukainure, Ochuko L

    2011-01-01

    The chemical properties of the African palm weevil, Rhychophorus phoenicis (F.) (Coleoptera: Curculionidae), larvae were evaluated using standard methodology. The chloroform-methanol extract yielded 37.12% on a dry basis. The oil was liquid at room temperature with a flash point of 36.0 °C. Analysis of the physical constants indicated values of 192.25 Wijs and 427.70 mg KOH/g as iodine and saponification, respectively. Fatty acid analysis of the extracted oil showed the presence of unsaturated fatty acids at low levels. Palmitic acid and stearic acid constituted 35.3 and 60.5% of the oil, respectively. The usual behaviour of the oil at room temperature, irrespective of the level of unsaturation of its constituent fatty acid was noted. The total protein content of the defatted palm weevil larva (dry basis) was estimated at 66.3%. The amino acid values compared favourably to FAO reference protein, except for tryptophan, which was limiting. All the other essential amino acids were adequate. Mineral analysis revealed high levels of potassium (1025 mg/100 g) and phosphorus (685 mg/100 g). The dried and defatted palm weevil lava represents a very good source of protein, and a good complement of essential amino acids.

  17. The effect of spatial scale on interactions between two weevils and their food plant

    NASA Astrophysics Data System (ADS)

    Hamid, Mohd Norowi; Perry, Joe N.; Powell, Wilf; Rennolls, Keith

    1999-09-01

    The effect of spatial scale on the interactions between the weevils Gymnetron pascuorum Gyll. and Mecinus pyraster Herbst and their host plant, ribwort plantain Plantago lanceolata L., was studied. Both weevils developed in plantain seedheads but occupied different niches within the seedhead. Seedheads were sampled annually from 162 plants at each of two experimental sites consisting of a series of habitat patches of two distinct sizes. Data were analysed from three site-years. Our results suggest that the density of available seedheads varied among years and this had a direct effect on abundance. M. pyraster, which develops in the stem within the seedhead, was more sensitive to changes in seedhead density than was G. pascuorum, which develops within the seeds themselves. The presence of a hedgerow along one side of the experimental site affected the pattern of colonisation of newly-created habitat patches by G. pascuorum but not by M. pyraster. Changes in spatial scale did not affect the variability of seedhead and insect densities. G. pascuorum had an aggregated distribution at all the spatial scales considered, but the distribution of M. pyraster was very scale dependent. The distributions of the two weevil species were positively associated amongst infested plants but not amongst infested seedheads. Behavioural and ecological factors that could explain the results of the data analyses are discussed.

  18. Greenhouse Studies of Thiamethoxam Effects on Pea Leaf Weevil, Sitona lineatus

    PubMed Central

    Cárcamo, Héctor; Herle, Carolyn; Hervet, Vincent

    2012-01-01

    The pea leaf weevil, Sitona lineatus L. (Coleoptera: Curculionidae), has recently emerged as an important pest of field peas in the Canadian prairies. Systemic seed-coated insecticides may provide a tool for the integrated pest management of this pest. Therefore, several controlled assays were performed in order to determine effects of a recently registered neonicotinoid, (thiamethoxam) on S. lineatus damage to foliage, weevil mortality, fertility, egg viability, larval mortality, and root nodule damage. Foliage damage was reduced by thiamethoxam relative to untreated controls during the seedling stage (2nd–5th nodes), but weevil adult mortality was only 15–30%. Fertility was reduced substantially through an extra seven-day delay in the preoviposition period and reduced egg-laying rate during the first 20 days of the study (92% lower than controls). Overall egg viability was lower in females fed foliage grown from thiamethoxamtreated seeds. Larval survivorship and nodule damage were also lower, but only when eggs were added to treated plants at the 2nd node stage. When eggs were added late, at the 5th node stage, thiamethoxam had no effect on larval survivorship or nodule damage. The results of this study led to the conclusion that seed treatments such as thiamethoxam have potential to be used as tools that will aid in the integrated pest management of S. lineatus, especially in combination with other methods such as biocontrol and trap crops. PMID:23461362

  19. Effects of the Diet on the Microbiota of the Red Palm Weevil (Coleoptera: Dryophthoridae)

    PubMed Central

    Montagna, Matteo; Chouaia, Bessem; Mazza, Giuseppe; Prosdocimi, Erica Maria; Crotti, Elena; Mereghetti, Valeria; Vacchini, Violetta; Giorgi, Annamaria; De Biase, Alessio; Longo, Santi; Cervo, Rita; Lozzia, Giuseppe Carlo; Alma, Alberto; Bandi, Claudio; Daffonchio, Daniele

    2015-01-01

    Rhynchophorus ferrugineus, also known as the red palm weevil, is regarded as the major pest of palm trees. Although studies of the microbiota associated with this species have been performed in recent years, little attention has been dedicated to the influence of the diet in shaping the host bacterial community. Here, we investigated the influence of food sources (i.e. palm tissues vs apple based substrate) on the microbial diversity associated with RPW, which was compared with the microbiota associated with wild individuals of the sister species Rhynchophorus vulneratus. The bacterial characterization was performed using a culture independent approach, i.e. the 16S rRNA pyrotag, and a culture dependent approach for a subset of the samples, in order to obtain bacterial isolates from RPW tissues. The bacterial community appeared significantly influenced by diet. Proteobacteria resulted to be the most abundant clade and was present in all the specimens of the three examined weevil groups. Within Proteobacteria, Enterobacteriaceae were identified in all the organs analysed, including hemolymph and reproductive organs. The apple-fed RPWs and the wild R. vulneratus showed a second dominant taxon within Firmicutes that was scarcely present in the microbiota associated with palm-fed RPWs. A comparative analysis on the bacteria associated with the palm tissues highlighted that 12 bacterial genera out of the 13 identified in the plant tissues were also present in weevils, thus indicating that palm tissues may present a source for bacterial acquisition. PMID:25635833

  20. Genetical Genomics Identifies the Genetic Architecture for Growth and Weevil Resistance in Spruce

    PubMed Central

    Porth, Ilga; White, Richard; Jaquish, Barry; Alfaro, René; Ritland, Carol; Ritland, Kermit

    2012-01-01

    In plants, relationships between resistance to herbivorous insect pests and growth are typically controlled by complex interactions between genetically correlated traits. These relationships often result in tradeoffs in phenotypic expression. In this study we used genetical genomics to elucidate genetic relationships between tree growth and resistance to white pine terminal weevil (Pissodes strobi Peck.) in a pedigree population of interior spruce (Picea glauca, P. engelmannii and their hybrids) that was growing at Vernon, B.C. and segregating for weevil resistance. Genetical genomics uses genetic perturbations caused by allelic segregation in pedigrees to co-locate quantitative trait loci (QTLs) for gene expression and quantitative traits. Bark tissue of apical leaders from 188 trees was assayed for gene expression using a 21.8K spruce EST-spotted microarray; the same individuals were genotyped for 384 SNP markers for the genetic map. Many of the expression QTLs (eQTL) co-localized with resistance trait QTLs. For a composite resistance phenotype of six attack and oviposition traits, 149 positional candidate genes were identified. Resistance and growth QTLs also overlapped with eQTL hotspots along the genome suggesting that: 1) genetic pleiotropy of resistance and growth traits in interior spruce was substantial, and 2) master regulatory genes were important for weevil resistance in spruce. These results will enable future work on functional genetic studies of insect resistance in spruce, and provide valuable information about candidate genes for genetic improvement of spruce. PMID:22973444

  1. Chemical Evaluation of African Palm Weevil, Rhychophorus phoenicis, Larvae as a Food Source

    PubMed Central

    Elemo, Babajide O; Elemo, Gloria N; Makinde, Ma; Erukainure, Ochuko L

    2011-01-01

    The chemical properties of the African palm weevil, Rhychophorus phoenicis (F.) (Coleoptera: Curculionidae), larvae were evaluated using standard methodology. The chloroform-methanol extract yielded 37.12% on a dry basis. The oil was liquid at room temperature with a flash point of 36.0 °C. Analysis of the physical constants indicated values of 192.25 Wijs and 427.70 mg KOH/g as iodine and saponification, respectively. Fatty acid analysis of the extracted oil showed the presence of unsaturated fatty acids at low levels. Palmitic acid and stearic acid constituted 35.3 and 60.5% of the oil, respectively. The usual behaviour of the oil at room temperature, irrespective of the level of unsaturation of its constituent fatty acid was noted. The total protein content of the defatted palm weevil larva (dry basis) was estimated at 66.3%. The amino acid values compared favourably to FAO reference protein, except for tryptophan, which was limiting. All the other essential amino acids were adequate. Mineral analysis revealed high levels of potassium (1025 mg/100 g) and phosphorus (685 mg/100 g). The dried and defatted palm weevil lava represents a very good source of protein, and a good complement of essential amino acids. PMID:22236060

  2. Effects of the diet on the microbiota of the red palm weevil (Coleoptera: Dryophthoridae).

    PubMed

    Montagna, Matteo; Chouaia, Bessem; Mazza, Giuseppe; Prosdocimi, Erica Maria; Crotti, Elena; Mereghetti, Valeria; Vacchini, Violetta; Giorgi, Annamaria; De Biase, Alessio; Longo, Santi; Cervo, Rita; Lozzia, Giuseppe Carlo; Alma, Alberto; Bandi, Claudio; Daffonchio, Daniele

    2015-01-01

    Rhynchophorus ferrugineus, also known as the red palm weevil, is regarded as the major pest of palm trees. Although studies of the microbiota associated with this species have been performed in recent years, little attention has been dedicated to the influence of the diet in shaping the host bacterial community. Here, we investigated the influence of food sources (i.e. palm tissues vs apple based substrate) on the microbial diversity associated with RPW, which was compared with the microbiota associated with wild individuals of the sister species Rhynchophorus vulneratus. The bacterial characterization was performed using a culture independent approach, i.e. the 16S rRNA pyrotag, and a culture dependent approach for a subset of the samples, in order to obtain bacterial isolates from RPW tissues. The bacterial community appeared significantly influenced by diet. Proteobacteria resulted to be the most abundant clade and was present in all the specimens of the three examined weevil groups. Within Proteobacteria, Enterobacteriaceae were identified in all the organs analysed, including hemolymph and reproductive organs. The apple-fed RPWs and the wild R. vulneratus showed a second dominant taxon within Firmicutes that was scarcely present in the microbiota associated with palm-fed RPWs. A comparative analysis on the bacteria associated with the palm tissues highlighted that 12 bacterial genera out of the 13 identified in the plant tissues were also present in weevils, thus indicating that palm tissues may present a source for bacterial acquisition.

  3. Molecular and morphological tools to distinguish Scyphophorus acupunctatus Gyllenhal, 1838: a new weevil pest of the endangered Eggers Agave from St Croix, US Virgin Islands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Agave Snout Weevil (ASW) or Sisal Weevil, Scyphophorus acupunctatus Gyllenhal, is one of the most destructive pests of agave plants, capable of destroying up to 70% of commercial crops, costing millions of dollars in damage to global industries including tequila, mezcal, perfume, henequen, nardo...

  4. Native leaf-tying caterpillars influence host plant use by the invasive Asiatic oak weevil through ecosystem engineering.

    PubMed

    Baer, Christina S; Marquis, Robert J

    2014-06-01

    We tested the effect of leaf-tying caterpillars, native ecosystem engineers, on the abundance and host feeding of an invasive insect, the Asiatic oak weevil, Cyrtepistomus castaneus (Roelofs). Leaf quality was previously thought to be the sole factor determining host use by C. castaneus, but adult weevils congregate in leaf ties made by lepidopteran larvae (caterpillars). Adult weevil abundance was naturally higher on Quercus alba and Q. velutina compared to four other tree species tested (Acer rubrum, Carya ovata, Cornus florida, and Sassafras albidum). These differences were associated with more natural leaf ties on the two Quercus species. In the laboratory, weevils fed on all six species but again preferred Q. alba and Q. velutina. When artificial ties were added to all six tree species, controlling for differences in leaf-tie density, adult weevil density increased on all six tree species, damage increased on all species but A. rubrum, and host ranking changed based on both abundance and damage. We conclude that leaf ties increase the local abundance of C. castaneus adults and their feeding. Thus, these native leaf-tying caterpillars engender the success of an invasive species via structural modification of potential host plants, the first described example of this phenomenon.

  5. Influence of Rice Seeding Rate on Efficacies of Neonicotinoid and Anthranilic Diamide Seed Treatments against Rice Water Weevil

    PubMed Central

    Hamm, Jason; Lanka, Srinivas; Stout, Michael

    2014-01-01

    Rice in the U.S. is frequently seeded at low rates and treated before sowing with neonicotinoid or anthranilic diamide insecticides to target the rice water weevil. A previous study of the influence of seeding rate on rice water weevil densities showed an inverse relationship between seeding rates and immature weevil densities. This study investigated interactive effects of seeding rate and seed treatment on weevil densities and rice yields; in particular, experiments were designed to determine whether seed treatments were less effective at low seeding rates. Four experiments were conducted over three years by varying seeding rates of rice treated at constant per seed rates of insecticide. Larval suppression by chlorantraniliprole was superior to thiamethoxam or clothianidin, and infestations at low seeding rates were up to 47% higher than at high seeding rates. Little evidence was found for the hypothesis that seed treatments are less effective at low seeding rates; in only one of four experiments was the reduction in weevil densities by thiamethoxam greater at high than at low seeding rates. However, suppression of larvae by neonicotinoid seed treatments in plots seeded at low rates was generally poor, and caution must be exercised when using the neonicotioids at low seeding rates. PMID:26462952

  6. Native leaf-tying caterpillars influence host plant use by the invasive Asiatic oak weevil through ecosystem engineering.

    PubMed

    Baer, Christina S; Marquis, Robert J

    2014-06-01

    We tested the effect of leaf-tying caterpillars, native ecosystem engineers, on the abundance and host feeding of an invasive insect, the Asiatic oak weevil, Cyrtepistomus castaneus (Roelofs). Leaf quality was previously thought to be the sole factor determining host use by C. castaneus, but adult weevils congregate in leaf ties made by lepidopteran larvae (caterpillars). Adult weevil abundance was naturally higher on Quercus alba and Q. velutina compared to four other tree species tested (Acer rubrum, Carya ovata, Cornus florida, and Sassafras albidum). These differences were associated with more natural leaf ties on the two Quercus species. In the laboratory, weevils fed on all six species but again preferred Q. alba and Q. velutina. When artificial ties were added to all six tree species, controlling for differences in leaf-tie density, adult weevil density increased on all six tree species, damage increased on all species but A. rubrum, and host ranking changed based on both abundance and damage. We conclude that leaf ties increase the local abundance of C. castaneus adults and their feeding. Thus, these native leaf-tying caterpillars engender the success of an invasive species via structural modification of potential host plants, the first described example of this phenomenon. PMID:25039212

  7. Effects of tillage practices on pea leaf weevil (Sitona lineatus L., Coleoptera: Curculionidae) biology and crop damage: a farm-scale study in the US Pacific Northwest.

    PubMed

    Hanavan, R P; Bosque-Pérez, N A

    2012-12-01

    The pea leaf weevil, Sitona lineatus L., is periodically a significant pest of pea, Pisum sativum L., in the Palouse region of northern Idaho and eastern Washington, USA. Previous on-station research demonstrated significantly greater adult pea leaf weevil colonization, immature survival, adult emergence and plant damage in conventional-tillage compared to no-tillage plots of pea. In experiments conducted during the 2006 and 2007 growing seasons, aerial and ground adult pea leaf weevil colonization of large-scale commercial pea fields under different tillage regimes in northern Idaho and eastern Washington was examined for the first time. Initial pea leaf weevil feeding damage, immature weevil densities and subsequent adult emergence from the fields were also assessed. During both years, significantly more adult pea leaf weevils were captured in conventional-tillage than in no-tillage fields during the crop establishment period in May. No-tillage soils remained wet longer in the spring and could not be planted by growers until later than conventional-tillage fields. Pea planted under conventional-tillage emerged earlier and had significantly greater feeding damage by the pea leaf weevil than no-tillage pea. Significantly, greater immature pea leaf weevil densities and subsequent adult emergence were observed in conventional-tillage than in no-tillage pea fields. Delayed development of root nodules in the cooler, moister conditions of no-tillage pea fields likely resulted in escape from attack and injury during the critical growth stages that ultimately influence yield. Results indicate that large-scale commercial no-tillage pea fields are less suitable for colonization and survival of the pea leaf weevil and suffer less weevil damage than fields under conventional tillage.

  8. Is the Invasive Species Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) (Argentine Stem Weevil) a Threat to New Zealand Natural Grassland Ecosystems?

    PubMed

    Barratt, Barbara I P; Barton, Diane M; Philip, Bruce A; Ferguson, Colin M; Goldson, Stephen L

    2016-01-01

    Listronotus bonariensis (Argentine stem weevil) is a stem-boring weevil that has become a major pasture pest in New Zealand, and cool climate turf grass in Australia. This species is also frequently found in native tussock grassland in New Zealand. Laboratory and field trials were established to determine the risk posed to both seedlings and established plants of three native grass species compared to what happens with a common host of this species, hybrid ryegrass (L. perenne X L. multiflorum). Adult weevil feeding damage scores were higher on Poa colensoi and Festuca novae-zelandiae than Chionochloa rigida. Oviposition was lower on P. colensoi than hybrid ryegrass, and no eggs were laid on F. novae-zelandiae. In field trials using the same four species established as spaced plants L. bonariensis laid more eggs per tiller in ryegrass in a low altitude pasture site than in ryegrass in a higher altitude site. No eggs were found on the three native grass species at the tussock sites, and only low numbers were found on other grasses at the low altitude pasture site. Despite this, numbers of adult weevils were extracted from the plants in the field trials. These may have comprised survivors of the original weevils added to the plants, together with new generation weevils that had emerged during the experiment. Irrespective, higher numbers were recovered from the tussock site plants than from those from the pasture site. It was concluded that L. bonariensis is likely to have little overall impact, but a greater impact on native grass seedling survival than on established plants.

  9. Is the Invasive Species Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) (Argentine Stem Weevil) a Threat to New Zealand Natural Grassland Ecosystems?

    PubMed Central

    Barratt, Barbara I. P.; Barton, Diane M.; Philip, Bruce A.; Ferguson, Colin M.; Goldson, Stephen L.

    2016-01-01

    Listronotus bonariensis (Argentine stem weevil) is a stem-boring weevil that has become a major pasture pest in New Zealand, and cool climate turf grass in Australia. This species is also frequently found in native tussock grassland in New Zealand. Laboratory and field trials were established to determine the risk posed to both seedlings and established plants of three native grass species compared to what happens with a common host of this species, hybrid ryegrass (L. perenne X L. multiflorum). Adult weevil feeding damage scores were higher on Poa colensoi and Festuca novae-zelandiae than Chionochloa rigida. Oviposition was lower on P. colensoi than hybrid ryegrass, and no eggs were laid on F. novae-zelandiae. In field trials using the same four species established as spaced plants L. bonariensis laid more eggs per tiller in ryegrass in a low altitude pasture site than in ryegrass in a higher altitude site. No eggs were found on the three native grass species at the tussock sites, and only low numbers were found on other grasses at the low altitude pasture site. Despite this, numbers of adult weevils were extracted from the plants in the field trials. These may have comprised survivors of the original weevils added to the plants, together with new generation weevils that had emerged during the experiment. Irrespective, higher numbers were recovered from the tussock site plants than from those from the pasture site. It was concluded that L. bonariensis is likely to have little overall impact, but a greater impact on native grass seedling survival than on established plants. PMID:27507979

  10. Radiation-induced changes in the cuticular hydrocarbons of the granary weevil and their relationship to desiccation and adult mortality

    SciTech Connect

    Sriharan, S. . Div. of Natural and Applied Sciences)

    1989-07-01

    Radiation from the nuclear waste products, such as Cesium-137, offers a scope and could be used for large scale disinfestation of grain. It is known that 0.15 to 0.20 kGy dose of gamma radiation is sufficient to kill insects in grain and grain products. However, the mode of action (in terms of lethal effects) is not understood. The purpose of this project, therefore, is to study the ways in which gamma radiation causes death in the granary weevil. Sitophilus granarius (L.) is a major and cosmopolitan pest of stored grain all over the world. Radiation damage, in particular the specific effects on the physiology of the insects exposed to radiation has been elucidated. In stored grain insects, conservation of water is a critical factor for their survival. Epicuticular hydrocarbons play an important role in water proofing. The laboratory rearing of the granary weevil was standardized so that large numbers of weevils of known ages could be produced for experimentation. Stock cultures were maintained at 27 {plus minus} 2{degree}C and 65 {plus minus} 5% R.H. Tests with various age groups (adults) and different doses of gamma radiation indicate that lethal effects are both age and dose related. Younger weevils, in general, survive for a longer period after irradiation compared to older weevils. Complete mortality results within about two weeks after exposure to gamma radiation at dose of 0.15 kGy or above. Data on wet and dry weights of the weevils kept at different (low, medium and higher) levels of humidity after irradiation indicate that gamma radiation induces greater water loss leading to desiccation and early death. Low humidity environment (17% R.H.) greatly accelerates lethal effects.

  11. Induced defenses change the chemical composition of pine seedlings and influence meal properties of the pine weevil Hylobius abietis.

    PubMed

    Lundborg, Lina; Fedderwitz, Frauke; Björklund, Niklas; Nordlander, Göran; Borg-Karlson, Anna-Karin

    2016-10-01

    The defense of conifers against phytophagous insects relies to a large extent on induced chemical defenses. However, it is not clear how induced changes in chemical composition influence the meal properties of phytophagous insects (and thus damage rates). The defense can be induced experimentally with methyl jasmonate (MeJA), which is a substance that is produced naturally when a plant is attacked. Here we used MeJA to investigate how the volatile contents of Scots pine (Pinus sylvestris L.) tissues influence the meal properties of the pine weevil (Hylobius abietis (L.)). Phloem and needles (both weevil target tissues) from MeJA-treated and control seedlings were extracted by n-hexane and analyzed by two-dimensional gas chromatography-mass spectrometry (2D GC-MS). The feeding of pine weevils on MeJA-treated and control seedlings were video-recorded to determine meal properties. Multivariate statistical analyses showed that phloem and needle contents of MeJA-treated seedlings had different volatile compositions compared to control seedlings. Levels of the pine weevil attractant (+)-α-pinene were particularly high in phloem of control seedlings with feeding damage. The antifeedant substance 2-phenylethanol occurred at higher levels in the phloem of MeJA-treated than in control seedlings. Accordingly, pine weevils fed slower and had shorter meals on MeJA-seedlings. The chemical compositions of phloem and needle tissues were clearly different in control seedlings but not in the MeJA-treated seedlings. Consequently, meal durations of mixed meals, i.e. both needles and phloem, were longer than phloem meals on control seedlings, while meal durations on MeJA seedlings did not differ between these meal contents. The meal duration influences the risk of girdling and plant death. Thus our results suggest a mechanism by which MeJA treatment may protect conifer seedlings against pine weevils. PMID:27417987

  12. Deleterious effects of plant cystatins against the banana weevil Cosmopolites sordidus.

    PubMed

    Kiggundu, Andrew; Muchwezi, Josephine; Van der Vyver, Christell; Viljoen, Altus; Vorster, Juan; Schlüter, Urte; Kunert, Karl; Michaud, Dominique

    2010-02-01

    The general potential of plant cystatins for the development of insect-resistant transgenic plants still remains to be established given the natural ability of several insects to compensate for the loss of digestive cysteine protease activities. Here we assessed the potential of cystatins for the development of banana lines resistant to the banana weevil Cosmopolites sordidus, a major pest of banana and plantain in Africa. Protease inhibitory assays were conducted with protein and methylcoumarin (MCA) peptide substrates to measure the inhibitory efficiency of different cystatins in vitro, followed by a diet assay with cystatin-infiltrated banana stem disks to monitor the impact of two plant cystatins, oryzacystatin I (OC-I, or OsCYS1) and papaya cystatin (CpCYS1), on the overall growth rate of weevil larvae. As observed earlier for other Coleoptera, banana weevils produce a variety of proteases for dietary protein digestion, including in particular Z-Phe-Arg-MCA-hydrolyzing (cathepsin L-like) and Z-Arg-Arg-MCA-hydrolyzing (cathepsin B-like) proteases active in mildly acidic conditions. Both enzyme populations were sensitive to the cysteine protease inhibitor E-64 and to different plant cystatins including OsCYS1. In line with the broad inhibitory effects of cystatins, OsCYS1 and CpCYS1 caused an important growth delay in young larvae developing for 10 days in cystatin-infiltrated banana stem disks. These promising results, which illustrate the susceptibility of C. sordidus to plant cystatins, are discussed in the light of recent hypotheses suggesting a key role for cathepsin B-like enzymes as a determinant for resistance or susceptibility to plant cystatins in Coleoptera. PMID:20035549

  13. Deleterious effects of plant cystatins against the banana weevil Cosmopolites sordidus.

    PubMed

    Kiggundu, Andrew; Muchwezi, Josephine; Van der Vyver, Christell; Viljoen, Altus; Vorster, Juan; Schlüter, Urte; Kunert, Karl; Michaud, Dominique

    2010-02-01

    The general potential of plant cystatins for the development of insect-resistant transgenic plants still remains to be established given the natural ability of several insects to compensate for the loss of digestive cysteine protease activities. Here we assessed the potential of cystatins for the development of banana lines resistant to the banana weevil Cosmopolites sordidus, a major pest of banana and plantain in Africa. Protease inhibitory assays were conducted with protein and methylcoumarin (MCA) peptide substrates to measure the inhibitory efficiency of different cystatins in vitro, followed by a diet assay with cystatin-infiltrated banana stem disks to monitor the impact of two plant cystatins, oryzacystatin I (OC-I, or OsCYS1) and papaya cystatin (CpCYS1), on the overall growth rate of weevil larvae. As observed earlier for other Coleoptera, banana weevils produce a variety of proteases for dietary protein digestion, including in particular Z-Phe-Arg-MCA-hydrolyzing (cathepsin L-like) and Z-Arg-Arg-MCA-hydrolyzing (cathepsin B-like) proteases active in mildly acidic conditions. Both enzyme populations were sensitive to the cysteine protease inhibitor E-64 and to different plant cystatins including OsCYS1. In line with the broad inhibitory effects of cystatins, OsCYS1 and CpCYS1 caused an important growth delay in young larvae developing for 10 days in cystatin-infiltrated banana stem disks. These promising results, which illustrate the susceptibility of C. sordidus to plant cystatins, are discussed in the light of recent hypotheses suggesting a key role for cathepsin B-like enzymes as a determinant for resistance or susceptibility to plant cystatins in Coleoptera.

  14. A degree-day model of sheep grazing influence on alfalfa weevil and crop characteristics.

    PubMed

    Goosey, Hayes B

    2012-02-01

    Domestic sheep (Ovis spp.) grazing is emerging as an integrated pest management tactic for alfalfa weevil, Hypera postica (Gyllenhal), management and a degree-day model is needed as a decision and support tool. In response to this need, grazing exclosures with unique degree-days and stocking rates were established at weekly intervals in a central Montana alfalfa field during 2008 and 2009. Analyses indicate that increased stocking rates and grazing degree-days were associated with decreased crop levels of weevil larvae. Larval data collected from grazing treatments were regressed against on-site and near-site temperatures that produced the same accuracy. The near-site model was chosen to encourage producer acceptance. The regression slope differed from zero, had an r2 of 0.83, and a root mean square error of 0.2. Crop data were collected to achieve optimal weevil management with forage quality and yield. Differences were recorded in crude protein, acid and neutral detergent fibers, total digestible nutrients, and mean stage by weight. Stem heights differed with higher stocking rates and degree-days recording the shortest alfalfa canopy height at harvest. The degree-day model was validated at four sites during 2010 with a mean square prediction error of 0.74. The recommendation from this research is to stock alfalfa fields in the spring before 63 DD with rates between 251 and 583 sheep days per hectare (d/ha). Sheep should be allowed to graze to a minimum of 106 and maximum of 150 DD before removal. This model gives field entomologists a new method for implementing grazing in an integrated pest management program.

  15. Effects of E-64, a cysteine proteinase inhibitor, on cowpea weevil growth, development, and fecundity

    SciTech Connect

    Murdock, L.L.; Shade, R.E.; Pomeroy, M.A.

    1988-06-01

    E-64, a specific inhibitor of cysteine proteinases, was incorporated into artificial seeds at low levels (0.01-0.25% by weight). It prolonged developmental time and increased mortality of the larval cowpea weevil, Callosobruchus maculatus (F.), in direct proportion to its concentration in the artificial seeds. The fecundity of females emerging from the artificial seeds was significantly decreased by E-64 concentrations of 0.06% and higher. These observations are compatible with the hypothesis that the midgut cysteine proteinase in C. maculatus is essential for normal growth and development.

  16. Radiation induced changes in the cuticular hydrocarbons of the granary weevil and their relationships to desiccation and adult mortality: Quarterly report, February 15, 1988-May 15, 1988

    SciTech Connect

    Not Available

    1988-01-01

    The overall goals and objectives as envisaged for the year (1988) have been pursued. The report of the work may broadly be outlined into three components: post irradiation mortality studies at different combinations of temperature and humidity (studies on the rate of moisture-loss in irradiated weevils and correlation with mortality): preliminary studies on the spiracles of the treated and untreated granary weevils; and extraction of epicuticular hydrocarbons Sitophilus granarius (L) for both irradiated and control (elucidate the after effects of irradiation and determination of radiation induced changes if any, in the cuticular hydrocarbons of weevils as a result of gamma radiation). 6 refs., 2 figs., 6 tabs.

  17. Laboratory and field efficacy of entomopathogenic fungi for the management of the sweetpotato weevil, Cylas formicarius (Coleoptera: Brentidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato weevil, Cylas formicarius (F.) (Coleoptera: Brentidae), is one of the most important pests of sweet potatoes in the world. With free trade between the United States and the U. S.-controlled Marianas Islands, C. formicarius has spread along with this commodity. Because of the cryptic ...

  18. Evidence for the presence of a female produced sex pheromone in the banana weevil, Cosmopolites sordidus Germar (Coleoptera: Curculionidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Behavior-modifying chemicals such as pheromones and kairomones have great potential in pest management. Studies reported here investigated chemical cues involved in mating and aggregation behavior of banana weevil, Cosmopolites sordidus, a major insect pest of banana in every country where bananas a...

  19. Evaluation of host-plant resistance of selected rice genotypes to the rice water weevil (Coleoptera:Curculionidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rice water weevil (RWW), Lissorhoptrus oryzophilus Kuschel, is the most important economic insect pest of rice in the United States. Currently, management of RWW mainly depends upon the use of insecticides due to the lack of effective alternate management tactics. A three year field study was co...

  20. Electroantennographic and behavioral responses of adults of raspberry weevil Aegorhinus superciliosus (Coleoptera: Curculionidae) to odors released from conspecific females.

    PubMed

    Mutis, Ana; Parra, Leonardo; Manosalva, Loreto; Palma, Rubén; Candia, Oscar; Lizama, Marcelo; Pardo, Fernando; Perich, Fernando; Quiroz, Andrés

    2010-08-01

    The raspberry weevil, Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae), is the most important pest in blueberry and raspberry fields in the south of Chile. In this study, we investigated the electroantennographic and behavioral responses of A. superciliosus to semiochemicals released from conspecific individual adults, with particular attention to male attraction to females. Odors released from females significantly attracted males in a Y-tube olfactometer. Gas chromatographic and mass spectral analysis of female volatile extracts revealed the presence of limonene and α-pinene. Electroantennogram recordings from both sexes indicated that males of A. superciliosus possess olfactory sensitivity for the R isomer of limonene and α-pinene, whereas females only perceived R-limonene. Behavioral assays using synthetic compounds showed that only R-limonene elicited an attraction response from male weevils. Field experiments confirmed the laboratory results, showing that R-limonene was attractive to weevils. This is the first report of intraspecific chemical communication in this weevil. We discuss the origin of these compounds, their possible role in the sexual behavior of this species, and their potential use in a pest control strategy.

  1. Resistance in Cultivated Sunflower Germplasm to the Red Sunflower Seed Weevil (Coleoptera: Curculionidae) in the Northern Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 6-year field study evaluated 52 sunflower, Helianthus annuus L., accessions, 20 breeding lines, and 9 interspecific crosses for resistance to infestation by naturally occurring populations of the red sunflower seed weevil, Smicronyx fulvus LeConte (Coleoptera: Curculionidae). Germplasm with potent...

  2. Non-linear degree day models for post-diapause development of the sunflower stem weevil (Curculionidae: Coleoptera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coloptera: Curculionidae), has caused yield losses across much of the western Great Plains. Little is known about the field biology of this pest. Simple prediction models, such as degree day models, are an integral tool for development...

  3. Sunflower stem weevil and its larval parasitoids in native sunflowers: Is parasitoid abundance and diversity greater in the US Southwest?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sunflower stem weevils (Cylindrocopturus adspersus) and their larval parasitoids were collected from stems of four native sunflower species (Helianthus annuus, H. nuttallii, H. pauciflorus, and H. petiolaris) from 147 sites across eight states in 2003 and 2005. Native H. annuus constituted the major...

  4. Antennal sensilla of the pine weevil Pissodes nitidus Roel. (Coleoptera: Curculionidae).

    PubMed

    Yan, Shan-Chun; Meng, Zhao-Jun; Peng, Lu; Liu, Dan

    2011-05-01

    The antennal sensilla of the pine weevil (Pissodes nitidus Roel.) were observed with scanning electron microscopy and transmission electron microscopy (TEM). The weevil antenna consists of a long scape, a pedicel, and a flagellum with 10 segments; the last four flagellum segments are fused, forming the antennal club, which is densely covered by various sensilla. In both sexes, six types of sensilla, sensilla palmate 1-4, sensilla chaetica, sensilla trichoid, sensilla basiconic 1-2, sensilla rod-like 1-3, sensilla falciform, were identified. Sensilla palmate represent a unique sensillum type in the Pissodes genus, and named here after their palmate shape, also represent the most abundant sensillum type. The TEM analysis of sensilla palmate represents the first such analysis of this sensillum type, and we speculate that the sensilla have an olfactory function. The sensilla trichoid and chaetica were evenly distributed on the three or four hair bands of the club, with much lower numbers than the palmate sensilla. No significant sexual differences in the types, numbers, and distribution of the antennal sensilla were found except for the size. TEM observation indicated that sensilla chaetica and trichoid may function as olfactory sensors. The putative functions of other sensilla type were also discussed with reference to their morphology, distribution, and ultrastructure.

  5. Response of Pea Varieties to Damage Degree of Pea Weevil, Bruchus pisorum L.

    PubMed Central

    Nikolova, Ivelina Mitkova

    2016-01-01

    A study was conducted to determine the response of five pea varieties (Pisum sativum L.) to damage degree of Bruchus pisorum: Glyans, Modus, Kamerton, and Svit (Ukrainian cultivars) and Pleven 4 (Bulgarian cultivar). The seeds were classified into three types: healthy seeds (type 1), damaged seeds with parasitoid emergence hole (type 2), and damaged seeds with bruchid emergence hole (type 3) and they were sown. It was found that the weight of 1000 seeds did not affect the field germination of the pea varieties. Healthy and damaged seeds with parasitoid emergence holes (first and second seed types) provide a very good opportunity for growth and development while plants from damaged seeds with bruchid emergence holes had poor germination and vigor and low productivity. These seeds cannot provide the creation of well-garnished seeding and stable crop yields. Among tested varieties, the Ukrainian variety Glyans had considerably higher seed weight, field germination, and index germination and weak egg-laying activity of B. pisorum compared to others. Use of spring pea cultivars that are weakly preferred by the pea weevil in breeding programs would reduce losses due to pea weevil and provide an environmentally safer option to its control. PMID:27042379

  6. Local and neighboring patch conditions alter sex-specific movement in banana weevils.

    PubMed

    Carval, Dominique; Perrin, Benjamin; Duyck, Pierre-François; Tixier, Philippe

    2015-12-01

    Understanding the mechanisms underlying the movements and spread of a species over time and space is a major concern of ecology. Here, we assessed the effects of an individual's sex and the density and sex ratio of conspecifics in the local and neighboring environment on the movement probability of the banana weevil, Cosmopolites sordidus. In a "two patches" experiment, we used radiofrequency identification tags to study the C. sordidus movement response to patch conditions. We showed that local and neighboring densities of conspecifics affect the movement rates of individuals but that the density-dependent effect can be either positive or negative depending on the relative densities of conspecifics in local and neighboring patches. We demonstrated that sex ratio also influences the movement of C. sordidus, that is, the weevil exhibits nonfixed sex-biased movement strategies. Sex-biased movement may be the consequence of intrasexual competition for resources (i.e., oviposition sites) in females and for mates in males. We also detected a high individual variability in the propensity to move. Finally, we discuss the role of demographic stochasticity, sex-biased movement, and individual heterogeneity in movement on the colonization process. PMID:27069621

  7. Endosymbiont diversity among sibling weevil species competing for the same resource

    PubMed Central

    2013-01-01

    Background Whereas the impact of endosymbionts on the ecology of their hosts is well known in some insect species, the question of whether host communities are influenced by endosymbionts remains largely unanswered. Notably, the coexistence of host species competing with each other, which is expected to be stabilized by their ecological differences, could be facilitated by differences in their endosymbionts. Yet, the composition of endosymbiotic communities housed by natural communities of competing host species is still almost unknown. In this study, we started filling this gap by describing and comparing the bacterial endosymbiotic communities of four sibling weevil species (Curculio spp.) that compete with each other to lay eggs into oak acorns (Quercus spp.) and exhibit marked ecological differences. Results All four species housed the primary endosymbiont Candidatus Curculioniphilus buchneri, yet each of these had a clearly distinct community of secondary endosymbionts, including Rickettsia, Spiroplasma, and two Wolbachia strains. Notably, three weevil species harbored their own predominant facultative endosymbiont and possessed the remaining symbionts at a residual infection level. Conclusions The four competing species clearly harbor distinct endosymbiotic communities. We discuss how such endosymbiotic communities could spread and keep distinct in the four insect species, and how these symbionts might affect the organization and species richness of host communities. PMID:23379718

  8. Cross-correlation patterns of air and soil temperatures, rainfall and Diaprepes abbreviatus root weevil in citrus.

    PubMed

    Li, Hong; Futch, Stephen H; Syvertsen, James P

    2007-11-01

    Time series cross-correlation analysis is appropriate when measuring relationships between two different time series. Using this approach, the authors quantified the relationship between the time series air temperature (AT), soil temperature (ST), rainfall, relative humidity (RH) and Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae) root weevil across a period of 30 months, and examined how closely the distribution of Diaprepes root weevil was related to AT, ST, rainfall and RH within this period of time. The study was conducted on a poorly drained Spodosol in a citrus [Citrus sinensis (L.) Osb.] grove in DeSoto County, south-west Florida, from April 2001 to September 2003. Adult weevil populations were monitored using 100 Tedders traps in a 30 x 15 m grid. Weather data (0.6 m AT, 0.1 m ST, 2 m rainfall and 2 m RH) were monitored by Florida Automated Weather Networks. The monthly mean and standard deviation were 22.3 +/- 4.0 degrees C for AT, 24.7 +/- 4.2 degrees C for ST, 146.0 +/- 122.7 mm for rainfall, 78.2 +/- 4.7% for RH and 0.74 +/- 0.59 adults trap(-1) for the root weevil. Weevil density was positively correlated with AT (r = 0.45, P < 0.0133), ST (r = 0.49, P < 0.0067) and rainfall (r = 0.38, P < 0.0450). The environmental variables AT, ST, rainfall and RH were correlated with each other (0.42 < r < 0.99, 0.0246 < P < 0.0001). All weather and Diaprepes variables were autocorrelated with each other within a time of 3 months. The cross-correlation coefficients varied between - 0.59 and 0.65 for the pair-variable between Diaprepes, AT, ST and rainfall, and these pair-variables were correlated across a time period of 4 months. The present results suggested that warm, wet conditions contributed to the root weevil outbreaks, and environmental temperature and rainfall were the variables most closely related to Diaprepes root weevil distribution in time. PMID:17674428

  9. [Influence of fruit size of Camellia meiocarpa on growth of oil tea weevil, Curculio chinensis (Coleoptera: Curculionidae)].

    PubMed

    Li, Zhi-wen; He, Li-hong; Ma, Ling; Xia, Jiao; Zeng, Ai-ping

    2014-12-01

    The relationship between mature larval mass of oil tea weevil (Curculio chinensis) and fruit volume of its host plant oil tea (Camellia meiocarpa) was fitted with Logistic equation in order to understand the restriction of host fruit size on large larval growth and development of the weevil. The results showed that the larval mass increased with the increasing host fruit volume, which was in good conformity with the Logistic model. The weevil larval growth followed the principle of diminishing marginal utility, and it could be divided into two periods, the fast-growing period (<3.216 cm3, one larva per fruit; <4.747 cm3, two larvae per fruit ) and the asymptotic growing period (>3.216 cm3, one larva per fruit; >4.747 cm3, two larvae per fruit). The minimum fruit size threshold was 1500 cm3 for one larva per fruit, and 2.539 cm3 for two larvae per fruit. The temporal pattern that the mature larvae exited from their host fruits was established, the number of larvae escaping from their host fruits decreased daily after the fruit collection, and the larval escaping peak largely appeared from 6:00 to 10:00 AM with 43.9% of total escaping number, and especially from 7:00 to 8:00 AM with 21.1% of total escaping number. The bigger the larvae, the earlier exited from their host fruits. The restriction of fruit size on growth and development of oil tea weevil was observed, and it should be a behavioral adaptation strategy to increase the offspring' s fitness for the parental weevil adults to oviposit on the bigger fruits.

  10. Enhancing Neoplasm Expression in Field Pea (Pisum sativum) via Intercropping and Its Significance to Pea Weevil (Bruchus pisorum) Management

    PubMed Central

    Teshome, Abel; Bryngelsson, Tomas; Mendesil, Esayas; Marttila, Salla; Geleta, Mulatu

    2016-01-01

    Neoplasm formation, a non-meristematic tissue growth on young field pea (Pisum sativum L.) pods is triggered in the absence of UV light and/or in response to oviposition by pea weevil (Bruchus pisorum L.). This trait is expressed in some genotypes [neoplastic (Np) genotypes] of P. sativum and has the capacity to obstruct pea weevil larval entry into developing seeds. In the present study, 26% of the tested accessions depicted the trait when grown under greenhouse conditions. However, UV light inhibits full expression of this trait and subsequently it is inconspicuous at the field level. In order to investigate UV light impact on the expression of neoplasm, particular Np genotypes were subjected to UV lamp light exposure in the greenhouse and sunlight at the field level. Under these different growing conditions, the highest mean percentage of Np pods was in the control chamber in the greenhouse (36%) whereas in single and double UV lamp chambers, the percentage dropped to 10 and 15%, respectively. Furthermore, when the same Np genotypes were grown in the field, the percentage of Np pods dropped significantly (7%). In order to enhance Np expression at the field level, intercropping of Np genotypes with sorghum was investigated. As result, the percentage of Np pods was threefold in intercropped Np genotypes as compared to those without intercropping. Therefore, intercropping Np genotypes with other crops such as sorghum and maize can facilitate neoplasm formation, which in turn can minimize the success rate of pea weevil larvae entry into developing seeds. Greenhouse artificial infestation experiments showed that pea weevil damage in Np genotypes is lower in comparison to wild type genotypes. Therefore, promoting Np formation under field conditions via intercropping can serve as part of an integrated pea weevil management strategy especially for small scale farming systems. PMID:27242855

  11. The gut microbiota of the pine weevil is similar across Europe and resembles that of other conifer-feeding beetles.

    PubMed

    Berasategui, Aileen; Axelsson, Karolin; Nordlander, Göran; Schmidt, Axel; Borg-Karlson, Anna-Karin; Gershenzon, Jonathan; Terenius, Olle; Kaltenpoth, Martin

    2016-08-01

    The pine weevil (Hylobius abietis, Coleoptera: Curculionidae) is an important pest of conifer seedlings in Europe. Despite its economic importance, little is known about the composition of its gut microbial community and the role it plays in mediating the weevil's ability to utilize conifers as a food source. Here, we characterized the gut bacterial communities of different populations of H. abietis across Europe and compared them to those of other beetles that occupy similar ecological niches. We demonstrate that the microbial community of H. abietis is similar at higher taxonomic levels (family and genus) across locations in Europe, with Wolbachia as the dominant microbe, followed by Enterobacteria and Firmicutes. Despite this similarity, we observed consistent differences between countries and locations, but not sexes. Our meta-analysis demonstrates that the gut bacterial community of the pine weevil is very similar to that of bark beetles that also exploit conifers as a food source. The Enterobacteriaceae symbionts of both host taxa are especially closely related phylogenetically. Conversely, the microbiota of H. abietis is distinct from that of closely related weevils feeding on nonconifer food sources, suggesting that the microbial community of the pine weevil is determined by the environment and may be relevant to host ecology. Furthermore, several H. abietis-associated members of the Enterobacteriaceae family are known to contain genes involved in terpenoid degradation. As such, we hypothesize that the gut microbial community is important for the utilization of conifer seedlings as a food source, either through the detoxification of plant secondary metabolites or through the supplementation of essential nutrients. PMID:27199034

  12. Laboratory Syntheses of Insect Pheromones.

    ERIC Educational Resources Information Center

    Cormier, Russell A.; Hoban, James N.

    1984-01-01

    Provides background information and procedures for the multi-step synthesis of tiger moth and boll weevil pheromones (sex attractants). These syntheses require several laboratory periods. The tiger moth pheromone synthesis is suitable for introductory organic chemistry while the boll weevil pheromone is recommended for an advanced laboratory…

  13. Systemic Insecticides Reduce Feeding, Survival and Fecundity of Adult Black Vine Weevils (Coleoptera: Curculionidae) on a Variety of Ornamental Nursery Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of bioassays were conducted to test the systemic activity of clothianidin, chlorantraniliprole, dinotefuran, and thiamethoxam against adult black vine weevils (Otiorhynchus sulcatus F.) on Taxus, Heuchera, Astilbe, Sedum, Euonymus, and Rhododendron grown in containers. The insecticides wer...

  14. Molecular genetic evidence for the involvement of a specific polygalacturonase, P2c, in the invasion and spread of Aspergillus flavus in cotton bolls.

    PubMed Central

    Shieh, M T; Brown, R L; Whitehead, M P; Cary, J W; Cotty, P J; Cleveland, T E; Dean, R A

    1997-01-01

    Isolates of Aspergillus flavus can be differentiated based on production of the polygalacturonase P2c. One group of isolates produces P2c, whereas the other group does not. In general, the group that produces P2c causes more damage and spreads to a greater extent in cotton bolls than those isolates that do not produce P2c. To determine whether P2c contributes to disease, the expression of pecA, the gene previously determined to encode P2c, was genetically altered. Adding the pecA gene to a strain previously lacking the gene resulted in the ability to cause significantly more damage to the intercarpellary membrane and the ability spread to a greater extent within the adjacent locule compared to the abilities of a control transformant. Conversely, eliminating the expression of pecA by targeted disruption caused a significant reduction in aggressiveness compared to that of a nondisrupted control transformant. These results provide direct evidence that P2c contributes to the invasion and spread of A. flavus during infection of cotton bolls. However, other factors not evaluated in this study also contribute to aggressiveness. PMID:9293005

  15. Cryptic iridescence in a fossil weevil generated by single diamond photonic crystals.

    PubMed

    McNamara, Maria E; Saranathan, Vinod; Locatelli, Emma R; Noh, Heeso; Briggs, Derek E G; Orr, Patrick J; Cao, Hui

    2014-11-01

    Nature's most spectacular colours originate in integumentary tissue architectures that scatter light via nanoscale modulations of the refractive index. The most intricate biophotonic nanostructures are three-dimensional crystals with opal, single diamond or single gyroid lattices. Despite intense interest in their optical and structural properties, the evolution of such nanostructures is poorly understood, due in part to a lack of data from the fossil record. Here, we report preservation of single diamond (Fd-3m) three-dimensional photonic crystals in scales of a 735,000 year old specimen of the brown Nearctic weevil Hypera diversipunctata from Gold Run, Canada, and in extant conspecifics. The preserved red to green structural colours exhibit near-field brilliancy yet are inconspicuous from afar; they most likely had cryptic functions in substrate matching. The discovery of pristine fossil examples indicates that the fossil record is likely to yield further data on the evolution of three-dimensional photonic nanostructures and their biological functions.

  16. Flight activity and dispersal of the cabbage seedpod weevil (Coleoptera: Curculionidae) are related to atmospheric conditions.

    PubMed

    Tansey, James A; Dosdall, Lloyd M; Keddie, Andrew; Olfert, Owen

    2010-08-01

    The cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae), is an invasive pest of canola (Brassica napus L. and Brassica rapa L.) in western Canada. Under current climatic conditions, C. obstrictus is spreading from established populations in southwestern Alberta at ≈ 55 km/yr. We studied the influence of climatic conditions on C. obstrictus flight behavior in 2007 and 2008 and eastward dispersal from the western border of Saskatchewan from 2002 to 2007. Positive linear relationships between increases in mean temperature and flight height and between greater mean maximum temperature and expanded dispersal distances were significant. Increases in relative humidity were associated with reduced flight heights and dispersal distances. We developed models that predict the relationships of temperature and relative humidity with flight height and with dispersal distance. We also discuss implications for C. obstrictus dispersal under current climatic conditions and in the context of predicted climate change.

  17. Multiple transgressions of Wallace's Line explain diversity of flightless Trigonopterus weevils on Bali.

    PubMed

    Tänzler, Rene; Toussaint, Emmanuel F A; Suhardjono, Yayuk R; Balke, Michael; Riedel, Alexander

    2014-05-01

    The fauna of Bali, situated immediately west of Wallace's Line, is supposedly of recent Javanese origin and characterized by low levels of endemicity. In flightless Trigonopterus weevils, however, we find 100% endemism for the eight species here reported for Bali. Phylogeographic analyses show extensive in situ differentiation, including a local radiation of five species. A comprehensive molecular phylogeny and ancestral area reconstruction of Indo-Malayan-Melanesian species reveals a complex colonization pattern, where the three Balinese lineages all arrived from the East, i.e. all of them transgressed Wallace's Line. Although East Java possesses a rich fauna of Trigonopterus, no exchange can be observed with Bali. We assert that the biogeographic picture of Bali has been dominated by the influx of mobile organisms from Java, but different relationships may be discovered when flightless invertebrates are studied. Our results highlight the importance of in-depth analyses of spatial patterns of biodiversity. PMID:24648218

  18. Multiple transgressions of Wallace's Line explain diversity of flightless Trigonopterus weevils on Bali

    PubMed Central

    Tänzler, Rene; Toussaint, Emmanuel F. A.; Suhardjono, Yayuk R.; Balke, Michael; Riedel, Alexander

    2014-01-01

    The fauna of Bali, situated immediately west of Wallace's Line, is supposedly of recent Javanese origin and characterized by low levels of endemicity. In flightless Trigonopterus weevils, however, we find 100% endemism for the eight species here reported for Bali. Phylogeographic analyses show extensive in situ differentiation, including a local radiation of five species. A comprehensive molecular phylogeny and ancestral area reconstruction of Indo-Malayan–Melanesian species reveals a complex colonization pattern, where the three Balinese lineages all arrived from the East, i.e. all of them transgressed Wallace's Line. Although East Java possesses a rich fauna of Trigonopterus, no exchange can be observed with Bali. We assert that the biogeographic picture of Bali has been dominated by the influx of mobile organisms from Java, but different relationships may be discovered when flightless invertebrates are studied. Our results highlight the importance of in-depth analyses of spatial patterns of biodiversity. PMID:24648218

  19. Activity of superoxide dismutase and catalase in the bean weevil (Acanthoscelides obtectus) selected for postponed senescence.

    PubMed

    Seslija, D; Blagojević, D; Spasić, M; Tucić, N

    1999-04-01

    Relationship of superoxide dismutase and catalase activities and aging were tested using bean weevil lines selected for postponed senescence. The beetles of different age (young and old) and mating status (virgin and mated) from the extended longevity lines were compared with their counterparts derived from the short-lived lines for activities of SOD and catalase. The old beetles from the long-lived lines had statistically significant higher activity of SOD than their controls. Although we did not find a significant effect of catalase on longevity, beetles originating from both types of lines exhibited an increased catalase activity during mating processes. In addition, we did observe an increased activity of catalase in one-day-old beetles of the short-lived lines relative to the same-aged individuals of the long-lived lines.

  20. Global Transcriptome Analysis of Constitutive Resistance to the White Pine Weevil in Spruce

    PubMed Central

    Verne, Sébastien; Jaquish, Barry; White, Rick; Ritland, Kermit

    2011-01-01

    Constitutive defense mechanisms are critical to the understanding of defense mechanisms in conifers because they constitute the first barrier to attacks by insect pests. In interior spruce, trees that are putatively resistant and susceptible to attacks by white pine weevil (Pissodes strobi) typically exhibit constitutive differences in traits such as resin duct size and number, bark thickness, and terpene content. To improve our knowledge of their genetic basis, we compared globally the constitutive expression levels of 17,825 genes between 20 putatively resistant and 20 putatively susceptible interior spruce trees from the British Columbia tree improvement program. We identified 54 upregulated and 137 downregulated genes in resistant phenotypes, relative to susceptible phenotypes, with a maximum fold change of 2.24 and 3.91, respectively. We found a puzzling increase of resistance by downregulated genes, as one would think that “procuring armaments” is the best defense. Also, although terpenes and phenolic compounds play an important role in conifer defense, we found few of these genes to be differentially expressed. We found 15 putative small heat-shock proteins (sHSP) and several other stress-related proteins to be downregulated in resistant trees. Downregulated putative sHSP belong to several sHSP classes and represented 58% of all tested putative sHSP. These proteins are well known to be involved in plant response to various kinds of abiotic stress; however, their role in constitutive resistance is not yet understood. The lack of correspondence between transcriptome profile clusters and phenotype classifications suggests that weevil resistance in spruce is a complex trait. PMID:21852250

  1. Trichobaris weevils distinguish amongst toxic host plants by sensing volatiles that do not affect larval performance.

    PubMed

    Lee, Gisuk; Joo, Youngsung; Diezel, Celia; Lee, Eun Ju; Baldwin, Ian T; Kim, Sang-Gyu

    2016-07-01

    Herbivorous insects use plant metabolites to inform their host plant selection for oviposition. These host-selection behaviours are often consistent with the preference-performance hypothesis; females oviposit on hosts that maximize the performance of their offspring. However, the metabolites used for these oviposition choices and those responsible for differences in offspring performance remain unknown for ecologically relevant interactions. Here, we examined the host-selection behaviours of two sympatric weevils, the Datura (Trichobaris compacta) and tobacco (T. mucorea) weevils in field and glasshouse experiments with transgenic host plants specifically altered in different components of their secondary metabolism. Adult females of both species strongly preferred to feed on D. wrightii rather than on N. attenuata leaves, but T. mucorea preferred to oviposit on N. attenuata, while T. compacta oviposited only on D. wrightii. These oviposition behaviours increased offspring performance: T. compacta larvae only survived in D. wrightii stems and T. mucorea larvae survived better in N. attenuata than in D. wrightii stems. Choice assays with nicotine-free, JA-impaired, and sesquiterpene-over-produced isogenic N. attenuata plants revealed that although half of the T. compacta larvae survived in nicotine-free N. attenuata lines, nicotine did not influence the oviposition behaviours of both the nicotine-adapted and nicotine-sensitive species. JA-induced sesquiterpene volatiles are key compounds influencing T. mucorea females' oviposition choices, but these sesquiterpenes had no effect on larval performance. We conclude that adult females are able to choose the best host plant for their offspring and use chemicals different from those that influence larval performance to inform their oviposition decisions. PMID:27146082

  2. Exaggerated trait allometry, compensation and trade-offs in the New Zealand giraffe weevil (Lasiorhynchus barbicornis).

    PubMed

    Painting, Christina J; Holwell, Gregory I

    2013-01-01

    Sexual selection has driven the evolution of exaggerated traits among diverse animal taxa. The production of exaggerated traits can come at a cost to other traits through trade-offs when resources allocated to trait development are limited. Alternatively some traits can be selected for in parallel to support or compensate for the cost of bearing the exaggerated trait. Male giraffe weevils (Lasiorhynchus barbicornis) display an extremely elongated rostrum used as a weapon during contests for mates. Here we characterise the scaling relationship between rostrum and body size and show that males have a steep positive allometry, but that the slope is non-linear due to a relative reduction in rostrum length for the largest males, suggesting a limitation in resource allocation or a diminishing requirement for large males to invest increasingly into larger rostra. We also measured testes, wings, antennae, fore- and hind-tibia size and found no evidence of a trade-off between these traits and rostrum length when comparing phenotypic correlations. However, the relative length of wings, antennae, fore- and hind-tibia all increased with relative rostrum length suggesting these traits may be under correlational selection. Increased investment in wing and leg length is therefore likely to compensate for the costs of flying with, and wielding the exaggerated rostrum of larger male giraffe weevils. These results provide a first step in identifying the potential for trait compensation and trades-offs, but are phenotypic correlations only and should be interpreted with care in the absence of breeding experiments. PMID:24312425

  3. External and internal structure of weevils (Insecta: Coleoptera) investigated with phase-contrast X-ray imaging

    NASA Astrophysics Data System (ADS)

    Hönnicke, M. G.; Cusatis, C.; Rigon, L.; Menk, R.-H.; Arfelli, F.; Foerster, L. A.; Rosado-Neto, G. H.

    2010-08-01

    Weevils (Coleoptera: Curculionidae) are identified by the external structure (dorsal, ventral and lateral features) and also by internal structure. The genitalia can be used to distinguish the sex and to identify the insects when the external structure appears identical. For this purpose, a destructive dissecting microscopy procedure is usually employed. In this paper, phase contrast X-ray imaging (radiography and tomography) is employed to investigate the internal structure (genitalia) of two entire species of weevils that presents very similar external structures ( Sitophilus oryzae and Sitophilus zeamais). The detection of features, which looks like the genital structure, shows that such non-destructive technique could be used as an alternative method for identification of insects. This method is especially useful in examining the internal features of precious species from museum collections, as already described in the recent literature.

  4. Heavy metal bioaccumulation and effects on water hyacinth weevils, Neochetina eichhorniae, feeding on water hyacinth, Eichhornia crassipes

    SciTech Connect

    Kay, S.H.; Haller, W.T.

    1986-08-01

    Both aquatic and terrestrial habitats frequently are subject to contamination by toxic heavy metals, yet very little is known about the influence of heavy metals absorbed by plant tissues upon the phytophagous insect fauna feeding upon these plants. The objectives of this study were to determine the influence of plant-absorbed metals upon the feeding, mortality, and body burdens of lead, cadmium, and copper in the water hyacinth weevil, Neochetina eichhorniae, imported for the biological control of water hyacinths (Eichhornia crassipes).

  5. Curculio Curculis lupus: biology, behavior and morphology of immatures of the cannibal weevil Anchylorhynchus eriospathae G. G. Bondar, 1943.

    PubMed

    de Medeiros, Bruno Augusto Souza; Bená, Daniela de Cássia; Vanin, Sergio Antonio

    2014-01-01

    Weevils are one of the largest groups of living organisms, with more than 60,000 species feeding mostly on plants. With only one exception, their described larvae are typical plant-feeders, with mouthparts adapted to chewing plant material. Here we describe the second case of a weevil with early-instar larvae adapted to killing conspecifics. We have studied the life history of Anchylorhynchus eriospathae G. G. Bondar, 1943 (Curculioninae: Derelomini sensuCaldara, Franz & Oberprieler (2014)), a species whose immatures feed internally on palm flowers and fruits. We provide detailed descriptions of all immature stages, including the extremely modified first-instar larva. Unlike other weevils and later instars, this stage exhibits a flat body with very long ventropedal lobe setae, a large and prognathous head with a gula, and falciform mandibles, each with a serrate retinaculum, that are used to fight with and eventually kill other first-instar larvae. We also provide biological notes on all stages and the results of behavioral tests that showed that larval aggression occurs only among early life stages. Finally we show that adult size is highly dependent on timing of oviposition. This specialized killer first instar probably evolved independently from the one other case known in weevils, in Revena rubiginosa (Conoderinae: Bariditae sensuPrena, Colonnelli & Hespenheide (2014)). Interestingly, both lineages inhabit the same hosts, raising the possibility that both intra- and inter-specific competition shaped those phenotypes. Given the scarcity of knowledge on early larval stages of concealed insect herbivores, it is possible that our findings represent an instance of a much broader phenomenon. Our observations also allowed us to conclude that Anchylorhynchus eriospathae and A. hatschbachi G. G. Bondar, 1943 are actually the same species, which we synonymize here by considering the latter as a junior synonym (new synonymy). PMID:25101231

  6. Curculio Curculis lupus: biology, behavior and morphology of immatures of the cannibal weevil Anchylorhynchus eriospathae G. G. Bondar, 1943

    PubMed Central

    Bená, Daniela de Cássia; Vanin, Sergio Antonio

    2014-01-01

    Weevils are one of the largest groups of living organisms, with more than 60,000 species feeding mostly on plants. With only one exception, their described larvae are typical plant-feeders, with mouthparts adapted to chewing plant material. Here we describe the second case of a weevil with early-instar larvae adapted to killing conspecifics. We have studied the life history of Anchylorhynchus eriospathae G. G. Bondar, 1943 (Curculioninae: Derelomini sensu Caldara, Franz & Oberprieler (2014)), a species whose immatures feed internally on palm flowers and fruits. We provide detailed descriptions of all immature stages, including the extremely modified first-instar larva. Unlike other weevils and later instars, this stage exhibits a flat body with very long ventropedal lobe setae, a large and prognathous head with a gula, and falciform mandibles, each with a serrate retinaculum, that are used to fight with and eventually kill other first-instar larvae. We also provide biological notes on all stages and the results of behavioral tests that showed that larval aggression occurs only among early life stages. Finally we show that adult size is highly dependent on timing of oviposition. This specialized killer first instar probably evolved independently from the one other case known in weevils, in Revena rubiginosa (Conoderinae: Bariditae sensu Prena, Colonnelli & Hespenheide (2014)). Interestingly, both lineages inhabit the same hosts, raising the possibility that both intra- and inter-specific competition shaped those phenotypes. Given the scarcity of knowledge on early larval stages of concealed insect herbivores, it is possible that our findings represent an instance of a much broader phenomenon. Our observations also allowed us to conclude that Anchylorhynchus eriospathae and A. hatschbachi G. G. Bondar, 1943 are actually the same species, which we synonymize here by considering the latter as a junior synonym (new synonymy). PMID:25101231

  7. Oviposition Preference of Pea Weevil, Bruchus pisorum L. Among Host and Non-host Plants and its Implication for Pest Management.

    PubMed

    Mendesil, Esayas; Rämert, Birgitta; Marttila, Salla; Hillbur, Ylva; Anderson, Peter

    2015-01-01

    The pea weevil, Bruchus pisorum L. is a major insect pest of field pea, Pisum sativum L. worldwide and current control practices mainly depend on the use of chemical insecticides that can cause adverse effects on environment and human health. Insecticides are also unaffordable by many small-scale farmers in developing countries, which highlights the need for investigating plant resistance traits and to develop alternative pest management strategies. The aim of this study was to determine oviposition preference of pea weevil among P. sativum genotypes with different level of resistance (Adet, 32410-1 and 235899-1) and the non-host leguminous plants wild pea (Pisum fulvum Sibth. et Sm.) and grass pea (Lathyrus sativus L.), in no-choice and dual-choice tests. Pod thickness and micromorphological traits of the pods were also examined. In the no-choice tests significantly more eggs were laid on the susceptible genotype Adet than on the other genotypes. Very few eggs were laid on P. fulvum and L. sativus. In the dual-choice experiments Adet was preferred by the females for oviposition. Furthermore, combinations of Adet with either 235899-1 or non-host plants significantly reduced the total number of eggs laid by the weevil in the dual-choice tests. Female pea weevils were also found to discriminate between host and non-host plants during oviposition. The neoplasm (Np) formation on 235899-1 pods was negatively correlated with oviposition by pea weevil. Pod wall thickness and trichomes might have influenced oviposition preference of the weevils. These results on oviposition behavior of the weevils can be used in developing alternative pest management strategies such as trap cropping using highly attractive genotype and intercropping with the non-host plants.

  8. Oviposition Preference of Pea Weevil, Bruchus pisorum L. Among Host and Non-host Plants and its Implication for Pest Management

    PubMed Central

    Mendesil, Esayas; Rämert, Birgitta; Marttila, Salla; Hillbur, Ylva; Anderson, Peter

    2016-01-01

    The pea weevil, Bruchus pisorum L. is a major insect pest of field pea, Pisum sativum L. worldwide and current control practices mainly depend on the use of chemical insecticides that can cause adverse effects on environment and human health. Insecticides are also unaffordable by many small-scale farmers in developing countries, which highlights the need for investigating plant resistance traits and to develop alternative pest management strategies. The aim of this study was to determine oviposition preference of pea weevil among P. sativum genotypes with different level of resistance (Adet, 32410-1 and 235899-1) and the non-host leguminous plants wild pea (Pisum fulvum Sibth. et Sm.) and grass pea (Lathyrus sativus L.), in no-choice and dual-choice tests. Pod thickness and micromorphological traits of the pods were also examined. In the no-choice tests significantly more eggs were laid on the susceptible genotype Adet than on the other genotypes. Very few eggs were laid on P. fulvum and L. sativus. In the dual-choice experiments Adet was preferred by the females for oviposition. Furthermore, combinations of Adet with either 235899-1 or non-host plants significantly reduced the total number of eggs laid by the weevil in the dual-choice tests. Female pea weevils were also found to discriminate between host and non-host plants during oviposition. The neoplasm (Np) formation on 235899-1 pods was negatively correlated with oviposition by pea weevil. Pod wall thickness and trichomes might have influenced oviposition preference of the weevils. These results on oviposition behavior of the weevils can be used in developing alternative pest management strategies such as trap cropping using highly attractive genotype and intercropping with the non-host plants. PMID:26779220

  9. Genetic variability and resistance of cultivars of cowpea [Vigna unguiculata (L.) Walp] to cowpea weevil (Callosobruchus maculatus Fabr.).

    PubMed

    Vila Nova, M X; Leite, N G A; Houllou, L M; Medeiros, L V; Lira Neto, A C; Hsie, B S; Borges-Paluch, L R; Santos, B S; Araujo, C S F; Rocha, A A; Costa, A F

    2014-03-31

    The cowpea weevil (Callosobruchus maculatus Fabr.) is the most destructive pest of the cowpea bean; it reduces seed quality. To control this pest, resistance testing combined with genetic analysis using molecular markers has been widely applied in research. Among the markers that show reliable results, the inter-simple sequence repeats (ISSRs) (microsatellites) are noteworthy. This study was performed to evaluate the resistance of 27 cultivars of cowpea bean to cowpea weevil. We tested the resistance related to the genetic variability of these cultivars using ISSR markers. To analyze the resistance of cultivars to weevil, a completely randomized test design with 4 replicates and 27 treatments was adopted. Five pairs of the insect were placed in 30 grains per replicate. Analysis of variance showed that the number of eggs and emerged insects were significantly different in the treatments, and the means were compared by statistical tests. The analysis of the large genetic variability in all cultivars resulted in the formation of different groups. The test of resistance showed that the cultivar Inhuma was the most sensitive to both number of eggs and number of emerged adults, while the TE96-290-12-G and MNC99-537-F4 (BRS Tumucumaque) cultivars were the least sensitive to the number of eggs and the number of emerged insects, respectively.

  10. Radiation induced changes in the cuticular hydrocarbons of the granary weevil and their relationships to desiccation and adult mortality: Half yearly report, February 16 to August 15, 1987. [Sitophilus granarius

    SciTech Connect

    Sriharan, S.

    1987-01-01

    This report outlines studies on the rate of moisture-loss in irradiated weevils and correlation loss of water with mortality. Further changes in the cuticular hydrocarbons of weevils as a result of gamma radiation were determined. 2 figs., 10 tabs.

  11. Effects of a non-native biocontrol weevil, Larinus planus, and other emerging threats on populations of the federally threatened Pitcher's thistle, Cirsium pitcheri

    USGS Publications Warehouse

    Havens, Kayri; Jolls, Claudia L.; Marik, Julie E.; Vitt, Pati; McEachern, A. Kathryn; Kind, Darcy

    2012-01-01

    Larinus planus Frabicius (Curculionidae), is a seed-eating weevil that was inadvertently introduced into the US and was subsequently distributed in the US and Canada for the control of noxious thistle species of rangelands. It has been detected recently in the federally threatened Pitcher's thistle (Cirsium pitcheri). We assayed weevil damage in a natural population of Pitcher's thistle at Whitefish Dunes State Park, Door County, WI and quantified the impact on fecundity. We then estimated the impact of this introduced weevil and other emerging threats on two natural, uninvaded populations of Pitcher's thistle for which we have long-term demographic data for 16 yr (Wilderness State Park, Emmet County, MI) and 23 yr (Miller High Dunes, Indiana Dunes National Lakeshore, Porter County, IN). We used transition matrices to determine growth rates and project the potential effects of weevil damage, inbreeding, goldfinch predation, and vegetative succession on Pitcher's thistle population viability. Based on our models, weevil seed predation reduced population growth rate by 10–12%, but this reduction was enough to reduce time to extinction from 24 yr to 13 yr and 8 yr to 5 yr in the MI and IN population, respectively. This impact is particularly severe, given most populations of Pitcher's thistle throughout its range hover near or below replacement. This is the first report of unanticipated ecological impacts from a biocontrol agent on natural populations of Cirsium pitcheri.

  12. Assessment of risk of introduction of Cylas formicarius elegantulus (Coleoptera: Brentidae) into weevil-free areas in the southern United States.

    PubMed

    Addo-Bediako, Abraham; Tameru, Baharnu; Jackai, Louis E N; Bonsi, Conrad K

    2007-04-01

    We assessed the risk associated with introduction of sweet potato weevil, Cylas formicarius elegantulus (Summers) (Coleoptera: Brentidae), from infested areas to noninfested areas via shipment of sweet potato, Ipomoea batatas (L.), roots within the southern United States. Our study quantifies the effectiveness of risk mitigation procedures of sweet potatoes before shipment in relation to introduction of the weevil. The risk assessment relied on literature and expert information to determine appropriate parameters. Using a computational model, Monte Carlo simulations were conducted to estimate the likelihood of introduction of sweet potato weevil. Risk management options were incorporated and the risk analyses were performed to assess how the risk could be reduced. The study found the risk of introduction of the weevil for both domestic shipment and imports of sweet potatoes into new areas within the southern United States to be low. Sensitivity analysis was performed to assess model stability and the impact of parameter changes. Based on the sensitivity analysis, the most critical input was the postharvest mitigation, followed by the number of weevils per ton of sweet potatoes. We concluded that maintaining mitigations with monitoring in conjunction with public education to stop illegal transport of sweet potatoes and alternate hosts would significantly reduce the risk of introduction.

  13. Cryptic iridescence in a fossil weevil generated by single diamond photonic crystals.

    PubMed

    McNamara, Maria E; Saranathan, Vinod; Locatelli, Emma R; Noh, Heeso; Briggs, Derek E G; Orr, Patrick J; Cao, Hui

    2014-11-01

    Nature's most spectacular colours originate in integumentary tissue architectures that scatter light via nanoscale modulations of the refractive index. The most intricate biophotonic nanostructures are three-dimensional crystals with opal, single diamond or single gyroid lattices. Despite intense interest in their optical and structural properties, the evolution of such nanostructures is poorly understood, due in part to a lack of data from the fossil record. Here, we report preservation of single diamond (Fd-3m) three-dimensional photonic crystals in scales of a 735,000 year old specimen of the brown Nearctic weevil Hypera diversipunctata from Gold Run, Canada, and in extant conspecifics. The preserved red to green structural colours exhibit near-field brilliancy yet are inconspicuous from afar; they most likely had cryptic functions in substrate matching. The discovery of pristine fossil examples indicates that the fossil record is likely to yield further data on the evolution of three-dimensional photonic nanostructures and their biological functions. PMID:25185581

  14. Wood digestion in Pselactus spadix Herbst--a weevil attacking marine timber structures.

    PubMed

    Oevering, Pascal; Pitman, Andrew J; Pandey, Krishna K

    2003-04-01

    Pselactus spadix tunnels timber structures in the marine environment. Recent studies reported a cosmopolitan distribution for this weevil, which is frequently found in harbour and port areas. P. spadix feeds on timber (hardwood and softwood) in immature and adult life stages, but its digestion of wood components had not been investigated. Using dry weight analyses of tunnel walls and frass produced, P. spadix adults consumed Scots pine with soft rot decay at a rate of 1.59 +/- 0.37 mg d-1 and the digestibility of this substrate was 57.96 +/- 5.89 (i.e. for 100 mg consumed SR-pine, 58 mg was digested). Using gravimetric analysis to quantify structural wood components in tunnel walls and frass, P. spadix adults were found to digest cellulose, lignin and hemicellulose with digestibility coefficients of 82.2, 41.2 and 14.5 respectively. Fourier Transform Infrared (FTIR) spectroscopy analyses of tunnel walls and frass of adults and larvae from soft rotted pine also indicated digestion of all structural components, with larvae digesting cellulose and lignin more efficiently than adults. When FTIR was employed to analyse adult tunnel walls and frass from undecayed pine, cellulose and hemicellulose were digested, but no evidence of lignin digestion was found. This study shows that adults digest lignin when soft rot is present and suggests a symbiotic function of wood degrading microorganisms. PMID:14618727

  15. Water-balance characteristics respond to changes in body size in subantarctic weevils.

    PubMed

    Chown, Steven L; Klok, C Jaco

    2003-01-01

    Several environmental factors leading to size-dependent mortality influence insect body size. Few investigations have been concerned with the ways in which the mechanisms underlying variation in water-balance characteristics evolve in response to changes in body size that occur independently of water-balance requirements. Using an explicitly phylogenetic analysis, we show how body size has changed over time in the Ectemnorhinus group of weevils and how water-balance characteristics have evolved in response to this change and changes in habitat use. The basal species in the group are all large bodied and from moist environments. In response to a change in resource availability, there was a marked decline in size within the group. Despite the reduction in water content and dehydration tolerance that this meant, evolution of low whole-animal water-loss rates and high tolerance of dehydration resulted in conservation of desiccation resistance. The return to moist habitats in the group resulted in a reduction in dehydration tolerance and an increase in water-loss rate. Thus, dehydration tolerance and water-loss rate respond rapidly both when there is selection for water conservation and when this requirement is relaxed. Future laboratory selection experiments might usefully explore both directions of water-balance evolution.

  16. On the Design of a Bioacoustic Sensor for the Early Detection of the Red Palm Weevil

    PubMed Central

    Rach, Miguel Martínez; Gomis, Héctor Migallón; Granado, Otoniel López; Malumbres, Manuel Perez; Campoy, Antonio Martí; Martín, Juan José Serrano

    2013-01-01

    During the last two decades Red Palm Weevil (RPW, Rynchophorus Ferrugineus) has become one of the most dangerous threats to palm trees in many parts of the World. Its early detection is difficult, since palm trees do not show visual evidence of infection until it is too late for them to recover. For this reason the development of efficient early detection mechanisms is a critical element of RPW pest management systems. One of the early detection mechanisms proposed in the literature is based on acoustic monitoring, as the activity of RPW larvae inside the palm trunk is audible for human operators under acceptable environmental noise levels (rural areas, night periods, etc.). In this work we propose the design of an autonomous bioacoustic sensor that can be installed in every palm tree under study and is able to analyze the captured audio signal during large periods of time. The results of the audio analysis would be reported wirelessly to a control station, to be subsequently processed and conveniently stored. That control station is to be accessible via the Internet. It is programmed to send warning messages when predefined alarm thresholds are reached, thereby allowing supervisors to check on-line the status and evolution of the palm tree orchards. We have developed a bioacoustic sensor prototype and performed an extensive set of experiments to measure its detection capability, achieving average detection rates over 90%. PMID:23364196

  17. Host plant recognition by the root feeding clover weevil, Sitona lepidus (Coleoptera: Curculionidae).

    PubMed

    Johnson, S N; Gregory, P J; Murray, P J; Zhang, X; Young, I M

    2004-10-01

    This study investigated the ability of neonatal larvae of the root-feeding weevil, Sitona lepidus Gyllenhal, to locate white clover Trifolium repens L. (Fabaceae) roots growing in soil and to distinguish them from the roots of other species of clover and a co-occurring grass species. Choice experiments used a combination of invasive techniques and the novel technique of high resolution X-ray microtomography to non-invasively track larval movement in the soil towards plant roots. Burrowing distances towards roots of different plant species were also examined. Newly hatched S. lepidus recognized T. repens roots and moved preferentially towards them when given a choice of roots of subterranean clover, Trifolium subterraneum L. (Fabaceae), strawberry clover Trifolium fragiferum L. (Fabaceae), or perennial ryegrass Lolium perenneL. (Poaceae). Larvae recognized T. repens roots, whether released in groups of five or singly, when released 25 mm (meso-scale recognition) or 60 mm (macro-scale recognition) away from plant roots. There was no statistically significant difference in movement rates of larvae.

  18. Host-plant dependent population genetics of the invading weevil Hypera postica.

    PubMed

    Iwase, S-I; Nakahira, K; Tuda, M; Kagoshima, K; Takagi, M

    2015-02-01

    Population genetics of invading pests can be informative for understanding their ecology. In this study, we investigated population genetics of the invasive alfalfa weevil Hypera postica in Fukuoka Prefecture, Japan. We analyzed mitochondrial tRNALeu-COII, nuclear EF-1α gene fragments, and Wolbachia infection in relation to three leguminous host plants: Vicia angustifolia, Vicia villosa, and a new host Astragalus sinicus cultivated as a honey source and green manure crop. A parsimony network generated from mitochondrial gene sequences uncovered two major haplotypic groups, Western and Egyptian. In contrast to reported Wolbachia infection of the Western strain in the United States, none of our analyzed individuals were infected. The absence of Wolbachia may contribute to the stable coexistence of mitochondrial strains through inter-strain reproductive compatibility. Hypera postica genetic variants for the mitochondrial and nuclear genes were associated neither with host plant species nor with two geographic regions (Hisayama and Kama) within Fukuoka. Mitochondrial haplogroups were incongruent with nuclear genetic variants. Genetic diversity at the nuclear locus was the highest for the populations feeding on V. angustifolia. The nuclear data for A. sinicus-feeding populations indicated past sudden population growth and extended Bayesian skyline plot analysis based on the mitochondrial and nuclear data showed that the growth of A. sinicus-feeding population took place within the past 1000 years. These results suggest a shorter history of A. sinicus as a host plant compared with V. angustifolia and a recent rapid growth of H. postica population using the new host A. sinicus.

  19. On the design of a bioacoustic sensor for the early detection of the red palm weevil.

    PubMed

    Martínez Rach, Miguel; Migallón Gomis, Héctor; López Granado, Otoniel; Perez Malumbres, Manuel; Martí Campoy, Antonio; Serrano Martín, Juan José

    2013-01-01

    During the last two decades Red Palm Weevil (RPW, Rynchophorus Ferrugineus) has become one of the most dangerous threats to palm trees in many parts of the World. Its early detection is difficult, since palm trees do not show visual evidence of infection until it is too late for them to recover. For this reason the development of efficient early detection mechanisms is a critical element of RPW pest management systems. One of the early detection mechanisms proposed in the literature is based on acoustic monitoring, as the activity of RPW larvae inside the palm trunk is audible for human operators under acceptable environmental noise levels (rural areas, night periods, etc.). In this work we propose the design of an autonomous bioacoustic sensor that can be installed in every palm tree under study and is able to analyze the captured audio signal during large periods of time. The results of the audio analysis would be reported wirelessly to a control station, to be subsequently processed and conveniently stored. That control station is to be accessible via the Internet. It is programmed to send warning messages when predefined alarm thresholds are reached, thereby allowing supervisors to check on-line the status and evolution of the palm tree orchards. We have developed a bioacoustic sensor prototype and performed an extensive set of experiments to measure its detection capability, achieving average detection rates over 90%. PMID:23364196

  20. Pseudomonas aeruginosa, a facultative pathogen of red palm weevil, Rhynchophorus ferrugineus.

    PubMed

    Banerjee, A; Dangar, T K

    1995-11-01

    Pseudomonas aeruginosa was identified as a facultative pathogen of red palm weevil. Intra-haemocoelic injection of the pathogen within larvae and pre-pupae was more effective at killing the insects [with a median lethal dose (LD50) of 9×10(2) to 2×10(3) bacteria/insect] than inoculation by force feeding (LD50 of 10(5) to 4×10(5) bacteria/insect) or by wading the insects in a suspension of the pathogen (LD50 of 10(5) to 2×10(5) bacteria/insect). Injection of 3×10(3) bacteria/insect killed 69% of larvae; small larvae were more susceptible (LD50 of 9×10(5) bacteria/larva) than either larger larvae (LD50 of 10(3) bacteria/larva) or pre-pupa. The median time to death of the small larvae following injection of P. aeruginosa was about 6 days but that following force feeding or wading was about 8 days. A secondary invader, Serratia marcescens, had no effect on the pathogenicity of P. aeruginosa but hastened death of larvae by about 3 days.

  1. Weapon allometry varies with latitude in the New Zealand giraffe weevil.

    PubMed

    Painting, C J; Buckley, T R; Holwell, G I

    2014-12-01

    Animal body size commonly shows a relationship with latitude to the degree that this phenomenon is one of the few 'rules' discussed in evolutionary ecology: Bergmann's rule. Although exaggerated secondary sexual traits frequently exhibit interesting relationships with body size (allometries) and are expected to evolve rapidly in response to environmental variation, the way in which allometry might interact with latitude has not been addressed. We present data showing latitudinal variation in body size and weapon allometry for the New Zealand giraffe weevil (Lasiorhynchus barbicornis). Males display an extremely elongated rostrum used as a weapon during fights for access to females. Consistent with Bergmann's rule, mean body size increased with latitude. More interestingly, weapon allometry also varied with latitude, such that lower latitude populations exhibited steeper allometric slopes between weapon and body size. To our knowledge, this is the first study to document a latitudinal cline in weapon allometry and is therefore a novel contribution to the collective work on Bergmann's rule and secondary sexual trait variation. PMID:25303121

  2. Genetic Status and Timing of a Weevil Introduction to Santa Cruz Island, Galápagos

    PubMed Central

    2014-01-01

    Successful invasive species can overcome or circumvent the potential genetic loss caused by an introduction bottleneck through a rapid population expansion and admixture from multiple introductions. We explore the genetic makeup and the timing of a species introduction to Santa Cruz Island in the Galápagos archipelago. We investigate the presence of processes that can maintain genetic diversity in populations of the broad-nosed weevil Galapaganus howdenae howdenae. Analyses of combined genotypes for 8 microsatellite loci showed evidence of past population size reductions through moment and likelihood-based estimators. No evidence of admixture through multiple introductions was found, but substantial current population sizes (N0 298, 95% credible limits 50–2300), genetic diversity comparable with long-established endemics (Mean number of alleles = 3.875), and lack of genetic structure across the introduced range (F ST = 0.01359) could suggest that foundations are in place for populations to rapidly recover any loss of genetic variability. The time estimates for the introduction into Santa Cruz support an accidental transfer during the colonization period (1832–1959) predating the spurt in human population growth. Our evaluation of the genetic status of G. h. howdenae suggests potential for population growth in addition to our field observations of a concurrent expansion in range and feeding preferences towards protected areas and endemic host plants. PMID:24399746

  3. Rhynchophorus palmarum in Disguise: Undescribed Polymorphism in the "Black" Palm Weevil.

    PubMed

    Löhr, Bernhard; Vásquez-Ordóñez, Aymer Andrés; Becerra Lopez-Lavalle, Luis Augusto

    2015-01-01

    During studies to adapt pheromone trapping of Rhynchophorus palmarum to the special coconut growing conditions at the Colombian Pacific coast, 152 atypically-colored specimens were captured in a total collection of 53,802 of the normally completely black weevil. Five specimens had the typical coloration of Rhynchophorus ferrugineus, an invasive species recently introduced to Aruba and Curação. A regional expansion of this invasion to the South American continent was feared and all atypical specimens were submitted to taxonomic analysis. Both conventional and molecular methods were employed. Conventional taxonomics confirmed the samples as belonging to R. palmarum but registered undescribed and species-atypical morphological variability in the subgular suture (wide vs. narrow), the ratio between intraocular distance and width of antennal scrobes (>0.35 vs. < 0.29) and the indentation of the mandibles (up to three mandibular teeth vs. bilobed). Molecular analysis placed all samples inspected, black and reddish alike, firmly within the R. palmarum group and the hypothesis of having inter-specific hybrids was rejected using co-dominant single sequence repeat markers with allelic specificity for both species. PMID:26683205

  4. Insect resistance management for stored product pests: a case study of cowpea weevil (Coleoptera: Bruchidae).

    PubMed

    Kang, Jung Koo; Pittendrigh, Barry R; Onstad, David W

    2013-12-01

    The cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae), can cause up to 100% yield loss of stored cowpea seeds in a few months in West Africa. Genes expressing toxins delaying insect maturation (MDTs) are available for genetic engineering. A simulation model was used to investigate the possible use of MDTs for managing C. maculatus. Specifically, we studied the effect of transgenic cowpea expressing an MDT, an insecticide, or both, on the evolution of resistance by C. maculatus at constant temperature. Transgenic cowpea expressing only a nonlethal MDT causing 50-100% maturation delay did not control C. maculatus well. Mortality caused by a maturation delay improved the efficacy of transgenic cowpea expressing only a lethal MDT, but significantly reduced the durability of transgenic cowpea Transgenic cowpea expressing only a lethal MDT causing 50% maturation delay and 90% mortality controlled C. maculatus better than one expressing only a nonlethal MDT, but its durability was only 2 yr. We concluded that transgenic cowpea expressing only an MDT has little value for managing C. maculatus. The resistance by C. maculatus to transgenic cowpea expressing only an insecticide rapidly evolved. Stacking a gene expressing a nonlethal MDT and a gene expressing an insecticide in transgenic cowpea did not significantly improve the durability of an insecticide, but stacking a gene expressing a lethal MDT and a gene expressing an insecticide in transgenic cowpea significantly improved the durability of an insecticide and an MDT. We also discussed this approach within the idea of using transgenic RNAi in pest control strategies. PMID:24498750

  5. Molecular phylogeny and biogeography of the weevil subfamily Platypodinae reveals evolutionarily conserved range patterns.

    PubMed

    Jordal, Bjarte H

    2015-11-01

    Platypodinae is a peculiar weevil subfamily of species that cultivate fungi in tunnels excavated in dead wood. Their geographical distribution is generally restricted, with genera confined to a single continent or large island, which provides a useful system for biogeographical research. This study establishes the first detailed molecular phylogeny of the group, with the aim of testing hypotheses on classification, diversification, and biogeography. A phylogeny was reconstructed based on 3648 nucleotides from COI, EF-1α, CAD, ArgK, and 28S. Tree topology was well resolved and indicated a strong correlation with geography, more so than predicted by previous morphology-based classifications. Tesserocerini was paraphyletic, with Notoplatypus as the sister group to a clade consisting of three main lineages of Tesserocerini and the recently evolved Platypodini. Austroplatypus formed the sister group to all remaining Platypodini and hence confirmed its separate status from Platypus. The Indo-Australian genera of Platypodini were strikingly paraphyletic, suggesting that the taxonomy of this tribe needs careful revision. Ancestral-area reconstructions in Lagrange and S-DIVA were ambiguous for nodes roughly older than 80 Ma. More recent events were firmly assessed and involved post-Gondwanan long-distance dispersal. The Neotropics was colonized three times, all from the Afrotropical region, with the latest event less than 25 Ma that included the ancestor of all Neotropical Platypodini. PMID:26190520

  6. Rhynchophorus palmarum in Disguise: Undescribed Polymorphism in the “Black” Palm Weevil

    PubMed Central

    Löhr, Bernhard; Vásquez-Ordóñez, Aymer Andrés; Becerra Lopez-Lavalle, Luis Augusto

    2015-01-01

    During studies to adapt pheromone trapping of Rhynchophorus palmarum to the special coconut growing conditions at the Colombian Pacific coast, 152 atypically-colored specimens were captured in a total collection of 53,802 of the normally completely black weevil. Five specimens had the typical coloration of Rhynchophorus ferrugineus, an invasive species recently introduced to Aruba and Curação. A regional expansion of this invasion to the South American continent was feared and all atypical specimens were submitted to taxonomic analysis. Both conventional and molecular methods were employed. Conventional taxonomics confirmed the samples as belonging to R. palmarum but registered undescribed and species-atypical morphological variability in the subgular suture (wide vs. narrow), the ratio between intraocular distance and width of antennal scrobes (>0.35 vs. < 0.29) and the indentation of the mandibles (up to three mandibular teeth vs. bilobed). Molecular analysis placed all samples inspected, black and reddish alike, firmly within the R. palmarum group and the hypothesis of having inter-specific hybrids was rejected using co-dominant single sequence repeat markers with allelic specificity for both species. PMID:26683205

  7. Insect resistance management for stored product pests: a case study of cowpea weevil (Coleoptera: Bruchidae).

    PubMed

    Kang, Jung Koo; Pittendrigh, Barry R; Onstad, David W

    2013-12-01

    The cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae), can cause up to 100% yield loss of stored cowpea seeds in a few months in West Africa. Genes expressing toxins delaying insect maturation (MDTs) are available for genetic engineering. A simulation model was used to investigate the possible use of MDTs for managing C. maculatus. Specifically, we studied the effect of transgenic cowpea expressing an MDT, an insecticide, or both, on the evolution of resistance by C. maculatus at constant temperature. Transgenic cowpea expressing only a nonlethal MDT causing 50-100% maturation delay did not control C. maculatus well. Mortality caused by a maturation delay improved the efficacy of transgenic cowpea expressing only a lethal MDT, but significantly reduced the durability of transgenic cowpea Transgenic cowpea expressing only a lethal MDT causing 50% maturation delay and 90% mortality controlled C. maculatus better than one expressing only a nonlethal MDT, but its durability was only 2 yr. We concluded that transgenic cowpea expressing only an MDT has little value for managing C. maculatus. The resistance by C. maculatus to transgenic cowpea expressing only an insecticide rapidly evolved. Stacking a gene expressing a nonlethal MDT and a gene expressing an insecticide in transgenic cowpea did not significantly improve the durability of an insecticide, but stacking a gene expressing a lethal MDT and a gene expressing an insecticide in transgenic cowpea significantly improved the durability of an insecticide and an MDT. We also discussed this approach within the idea of using transgenic RNAi in pest control strategies.

  8. Divergence in replicated phylogenies: the evolution of partial post-mating prezygotic isolation in bean weevils.

    PubMed

    Fricke, C; Arnqvist, G

    2004-11-01

    By tradition, speciation research has been focused on processes leading to either premating or post-zygotic reproductive isolation. The processes which generate isolation after mating but before zygote formation are less well understood. Here, we study divergence in characters which contribute to post-mating prezygotic isolation, such as egg production and remating rate. We propose that 'replicated' laboratory phylogenies with known histories can be used to yield insights into the processes of divergence. We performed a series of cross-matings between populations within two strains of the bean weevil Callosobruchus maculatus. Each strain has a unique and independent origin and both have been kept in the same set of laboratories during the last few decades. Our results show that divergence has occurred between laboratory populations within strains with regards to the effects that mating has on female reproductive behaviour, showing that the evolution of partial post-mating prezygotic isolation can be rapid. More importantly, the pattern of divergence across populations was distinct in the two strains, suggesting that coevolutionary trajectories are not determined by environmental factors but are to some extent arbitrary. We discuss the limitations of the novel empirical strategy employed here, and conclude that our results lend support to the hypothesis that post-mating sexual selection is capable of rapidly generating post-mating prezygotic isolation.

  9. Weapon allometry varies with latitude in the New Zealand giraffe weevil.

    PubMed

    Painting, C J; Buckley, T R; Holwell, G I

    2014-12-01

    Animal body size commonly shows a relationship with latitude to the degree that this phenomenon is one of the few 'rules' discussed in evolutionary ecology: Bergmann's rule. Although exaggerated secondary sexual traits frequently exhibit interesting relationships with body size (allometries) and are expected to evolve rapidly in response to environmental variation, the way in which allometry might interact with latitude has not been addressed. We present data showing latitudinal variation in body size and weapon allometry for the New Zealand giraffe weevil (Lasiorhynchus barbicornis). Males display an extremely elongated rostrum used as a weapon during fights for access to females. Consistent with Bergmann's rule, mean body size increased with latitude. More interestingly, weapon allometry also varied with latitude, such that lower latitude populations exhibited steeper allometric slopes between weapon and body size. To our knowledge, this is the first study to document a latitudinal cline in weapon allometry and is therefore a novel contribution to the collective work on Bergmann's rule and secondary sexual trait variation.

  10. Identification of plant odours activating receptor neurones in the weevil Pissodes notatus F. (Coleoptera, Curculionidae).

    PubMed

    Bichão, H; Borg-Karlson, A-K; Araújo, J; Mustaparta, H

    2003-03-01

    Plants release complex mixtures of volatiles important in the interaction with insects and other organisms. In the search for compounds that contribute to the perception of odour quality in the weevil Pissodes notatus, single olfactory receptor neurones on the antennae were screened for sensitivity to naturally produced plant volatiles by the use of gas chromatography linked to single cell recordings. We here present 60 olfactory neurones responding to 25 of the numerous compounds released by host and non-host plants. All the neurones show high selectivity and are classified into 12 distinct types. The two most abundant types respond to alpha-pinene, beta-pinene, and 3-carene ( n=17), and to isopinocamphone and pinocamphone ( n=17), respectively. Other neurone types respond to limonene ( n=9), beta-phellandrene ( n=3), and fenchone ( n=4). Responses to beta-caryophyllene ( n=1) and to ethanol ( n=4) are also shown. Except for two pairs, the neurone types do not show overlap of the molecular receptive range. The active compounds are present in the host, Pinus pinaster, as well as in non-hosts, supporting the idea that plant odour quality is mediated by the ratio of the compounds rather than specific odorants.

  11. Transcriptome Analysis and Systemic RNAi Response in the African Sweetpotato Weevil (Cylas puncticollis, Coleoptera, Brentidae)

    PubMed Central

    Prentice, Katterinne; Pertry, Ine; Christiaens, Olivier; Bauters, Lander; Bailey, Ana; Niblett, Chuck; Ghislain, Marc; Gheysen, Godelieve; Smagghe, Guy

    2015-01-01

    The African sweetpotato weevil (SPW) Cylas puncticollis Boheman is one of the most important constraints of sweetpotato production in Sub-Saharan Africa and yet is largely an uncharacterized insect pest. Here, we report on the transcriptome analysis of SPW generated using an Illumina platform. More than 213 million sequencing reads were obtained and assembled into 89,599 contigs. This assembly was followed by a gene ontology annotation. Subsequently, a transcriptome search showed that the necessary RNAi components relevant to the three major RNAi pathways, were found to be expressed in SPW. To address the functionality of the RNAi mechanism in this species, dsRNA was injected into second instar larvae targeting laccase2, a gene which encodes an enzyme involved in the sclerotization of insect exoskeleton. The body of treated insects showed inhibition of sclerotization, leading eventually to death. Quantitative Real Time PCR (qPCR) confirmed this phenotype to be the result of gene silencing. Together, our results provide valuable sequence data on this important insect pest and demonstrate that a functional RNAi pathway with a strong and systemic effect is present in SPW and can further be explored as a new strategy for controlling this important pest. PMID:25590333

  12. The effects of island forest restoration on open habitat specialists: the endangered weevil Hadramphus spinipennis Broun and its host-plant Aciphylla dieffenbachii Kirk.

    PubMed

    Fountain, Emily D; Malumbres-Olarte, Jagoba; Cruickshank, Robert H; Paterson, Adrian M

    2015-01-01

    Human alteration of islands has made restoration a key part of conservation management. As islands are restored to their original state, species interactions change and some populations may be impacted. In this study we examine the coxella weevil, (Hadramphus spinipennis Broun) and its host-plant Dieffenbach's speargrass (Aciphylla dieffenbachii Kirk), which are both open habitat specialists with populations on Mangere and Rangatira Islands, Chathams, New Zealand. Both of these islands were heavily impacted by the introduction of livestock; the majority of the forest was removed and the weevil populations declined due to the palatability of their host-plant to livestock. An intensive reforestation program was established on both islands over 50 years ago but the potential impacts of this restoration project on the already endangered H. spinipennis are poorly understood. We combined genetic and population data from 1995 and 2010-2011 to determine the health and status of these species on both islands. There was some genetic variation between the weevil populations on each island but little variation within the species as a whole. The interactions between the weevil and its host-plant populations appear to remain intact on Mangere, despite forest regeneration. A decline in weevils and host-plant on Rangatira does not appear to be caused by canopy regrowth. We recommend that (1) these populations be monitored for ongoing effects of long-term reforestation, (2) the cause of the decline on Rangatira be investigated, and (3) the two populations of weevils be conserved as separate evolutionarily significant units. PMID:25699201

  13. The effects of island forest restoration on open habitat specialists: the endangered weevil Hadramphus spinipennis Broun and its host-plant Aciphylla dieffenbachii Kirk

    PubMed Central

    Malumbres-Olarte, Jagoba; Cruickshank, Robert H.; Paterson, Adrian M.

    2015-01-01

    Human alteration of islands has made restoration a key part of conservation management. As islands are restored to their original state, species interactions change and some populations may be impacted. In this study we examine the coxella weevil, (Hadramphus spinipennis Broun) and its host-plant Dieffenbach’s speargrass (Aciphylla dieffenbachii Kirk), which are both open habitat specialists with populations on Mangere and Rangatira Islands, Chathams, New Zealand. Both of these islands were heavily impacted by the introduction of livestock; the majority of the forest was removed and the weevil populations declined due to the palatability of their host-plant to livestock. An intensive reforestation program was established on both islands over 50 years ago but the potential impacts of this restoration project on the already endangered H. spinipennis are poorly understood. We combined genetic and population data from 1995 and 2010–2011 to determine the health and status of these species on both islands. There was some genetic variation between the weevil populations on each island but little variation within the species as a whole. The interactions between the weevil and its host-plant populations appear to remain intact on Mangere, despite forest regeneration. A decline in weevils and host-plant on Rangatira does not appear to be caused by canopy regrowth. We recommend that (1) these populations be monitored for ongoing effects of long-term reforestation, (2) the cause of the decline on Rangatira be investigated, and (3) the two populations of weevils be conserved as separate evolutionarily significant units. PMID:25699201

  14. Radiation induced changes in the cuticular hydrocarbons of the granary weevil and their relationships to desiccation and adult mortality: Annual report, February 16, 1987-November 20, 1987

    SciTech Connect

    Sriharan, S.

    1987-01-01

    The overall goals and objectives as envisaged for the year (1987) have been pursued. The report of the work may broadly be outlined into two components: post irradiation mortality studies at different combinations of temperature and humidity (studies on the rate of moisture-loss in irradiated weevils and correlation with mortality); and extraction of epicuticular hydrocarbons Sitophilus granarius (L) for both irradiated and control (elucidate the after effects of irradiation and determination of radiation induced changes if any, in the cuticular hydrocarbons of weevils as a result of gamma radiation). 25 figs., 6 tabs.

  15. Data on the abundance of the banana weevil Cosmopolites sordidus and of the earwig Euborellia caraibea in bare soil and cover crop plots

    PubMed Central

    Carval, Dominique; Resmond, Rémi; Achard, Raphaël; Tixier, Philippe

    2016-01-01

    The data presented in this article are related to the research article entitled “Cover cropping reduces the abundance of the banana weevil Cosmopolites sordidus but does not reduce its damage to the banana plants” (Carval et al., in press) [1]. This article describes how the abundance of the banana weevil, Cosmopolites sordidus, and the abundance of the earwig Euborellia caraibea were affected by the addition of a cover crop. The field data set is made publicly available to enable critical or extended analyzes. PMID:27222854

  16. Data on the abundance of the banana weevil Cosmopolites sordidus and of the earwig Euborellia caraibea in bare soil and cover crop plots.

    PubMed

    Carval, Dominique; Resmond, Rémi; Achard, Raphaël; Tixier, Philippe

    2016-06-01

    The data presented in this article are related to the research article entitled "Cover cropping reduces the abundance of the banana weevil Cosmopolites sordidus but does not reduce its damage to the banana plants" (Carval et al., in press) [1]. This article describes how the abundance of the banana weevil, Cosmopolites sordidus, and the abundance of the earwig Euborellia caraibea were affected by the addition of a cover crop. The field data set is made publicly available to enable critical or extended analyzes. PMID:27222854

  17. Speciation in the asexual realm: is the parthenogenetic weevil Naupactus cervinus a complex of species in statu nascendi?

    PubMed

    Rodriguero, M S; Lanteri, A A; Confalonieri, V A

    2013-09-01

    Population genetic theory shows that asexual organisms may evolve into species, which behave as independent evolutionary units. As a result, they form genotypic clusters separated by deep gaps due to geographic isolation and/or divergent selection. Identification of several genetically divergent groups of weevils embodied in the nominal species Naupactus cervinus deserves further study, in order to test if these lineages are evolving independently. In the present paper we tested if the parthenogenetic weevil N. cervinus, native to South America and broadly distributed throughout the world, contains more than one evolutionary unit. For this purpose, we applied three different approaches, a multilocus phylogenetic analysis, the GMYC approach and the K/θ method. We accomplished these analyses through a survey of mitochondrial (COI and COII genes) and nuclear (ITS1 sequence) genetic variation and morphometric analysis in a sample which included individuals from different locations within the native geographic range of N. cervinus. In addition, we compared the divergence accumulated in this species with that in another weevil of the same tribe (Naupactini) showing identical reproductive mode to see if similar levels of morphological variation matches similar levels of genetic divergence. We report the presence of two independent evolutionary units living in sympatry in forest areas. The incongruence between mitochondrial and nuclear datasets analyzed herein reflects incomplete lineage sorting of the nuclear marker and different evolutionary rates between genomes. Ecological divergence driven by natural selection (sympatry) or secondary contact after geographic isolation (allopatry) might explain the deep gaps in mitochondrial phylogenies. Instead, Wolbachia infection was ruled out as a causal factor for such differentiation. We conclude that N. cervinus is probably a species complex with at least two well differentiated lineages that would represent a cluster of

  18. Efficacy of Rice Insecticide Seed Treatments at Selected Nitrogen Rates for Control of the Rice Water Weevil (Coleoptera: Curculionidae).

    PubMed

    Everett, Mallory; Lorenz, Gus; Slaton, Nathan; Hardke, Jarrod

    2015-08-01

    Seed-applied insecticides are the standard control method used in the United States to minimize rice water weevil (Lissorhoptrus oryzophilus Kuschel) injury to rice (Oryza sativa L.) roots, and often results in greater yields than rice that receives no seed-applied insecticide. Yield increases from seed-applied insecticides often occur even when insect pressure is low and should not cause yield loss. The research objective was to evaluate the effect of urea-nitrogen rate and seed-applied insecticide on number of rice water weevil larvae, nitrogen uptake, and rice grain yield. Six trials were conducted at the Pine Tree Research Station (PTRS) and the Rice Research Extension Center (RREC) to examine the response of rice plants receiving different insecticide-seed treatments and urea-nitrogen rate combinations. Insecticide-seed treatments included label rates of clothianidin, thiamethoxam, and a no-insecticide (fungicide only) control, in combination with season-total nitrogen rates of 0, 50, 100, 150, and 200 kg urea-nitrogen/ha. Rice seed that was treated with clothianidin or thiamethoxam generally had equal numbers of rice water weevil larvae, which were significantly fewer compared with rice that received no insecticide with an equivalent urea-nitrogen rate. Nitrogen uptake at panicle differentiation was not affected by insecticide-seed treatments at four of six sites and usually increased positively and linearly as urea-nitrogen rate increased. As urea-nitrogen rate increased, grain yield increased either linearly or nonlinearly. Averaged across urea-nitrogen rates, both insecticide seed treatments had similar yields that were 4 to 7% greater than the grain yields of rice that received no insecticide at four of the five harvested sites. PMID:26470317

  19. Efficacy of Rice Insecticide Seed Treatments at Selected Nitrogen Rates for Control of the Rice Water Weevil (Coleoptera: Curculionidae).

    PubMed

    Everett, Mallory; Lorenz, Gus; Slaton, Nathan; Hardke, Jarrod

    2015-08-01

    Seed-applied insecticides are the standard control method used in the United States to minimize rice water weevil (Lissorhoptrus oryzophilus Kuschel) injury to rice (Oryza sativa L.) roots, and often results in greater yields than rice that receives no seed-applied insecticide. Yield increases from seed-applied insecticides often occur even when insect pressure is low and should not cause yield loss. The research objective was to evaluate the effect of urea-nitrogen rate and seed-applied insecticide on number of rice water weevil larvae, nitrogen uptake, and rice grain yield. Six trials were conducted at the Pine Tree Research Station (PTRS) and the Rice Research Extension Center (RREC) to examine the response of rice plants receiving different insecticide-seed treatments and urea-nitrogen rate combinations. Insecticide-seed treatments included label rates of clothianidin, thiamethoxam, and a no-insecticide (fungicide only) control, in combination with season-total nitrogen rates of 0, 50, 100, 150, and 200 kg urea-nitrogen/ha. Rice seed that was treated with clothianidin or thiamethoxam generally had equal numbers of rice water weevil larvae, which were significantly fewer compared with rice that received no insecticide with an equivalent urea-nitrogen rate. Nitrogen uptake at panicle differentiation was not affected by insecticide-seed treatments at four of six sites and usually increased positively and linearly as urea-nitrogen rate increased. As urea-nitrogen rate increased, grain yield increased either linearly or nonlinearly. Averaged across urea-nitrogen rates, both insecticide seed treatments had similar yields that were 4 to 7% greater than the grain yields of rice that received no insecticide at four of the five harvested sites.

  20. Mass rearing the weevil Hylobius transversovittatus (Coleoptera: Curculionidae), biological control agent of Lythrum salicaria, on semiartificial diet.

    PubMed

    Blossey, B; Eberts, D; Morrison, E; Hunt, T R

    2000-12-01

    Lythrum salicaria L., purple loosestrife, an invasive Eurasian perennial, is degrading wetlands across temperate North America. Chemical, physical, and mechanical methods failed to provide long-term control. Therefore, four host-specific insect species (two leaf feeders, a root feeder, and a flower feeder) were introduced as biological control agents. To increase the availability of adults of the root feeding weevil Hylobius transversovittatus Goeze for field releases, we developed a semiartificial diet. Suitability of different diet formulations (varying vitamin mixes, salt mixes, antimicrobials, water content, root content) and temperatures for larval development were evaluated. We also monitored how rearing on artificial diet and the number of larvae per container affected larval development time, larval survival, adult weight, and incidences of deformities. Rearing larvae on artificial diet reduced development time from 1-2 yr to 2-3 mo. Larval development was fastest and survival rates highest under constant temperatures of 25 degrees C. Hatch rate and larval survival decreased if eggs were surface sterilized. Using FABCO antimicrobials could not prevent fungal contamination; use of methyl paraben and sorbic acid was successful in suppressing fungal and bacterial growth throughout larval development time to <10%. The moisture content of the diet did not significantly affect larval survival, development, or adult weight. Decreasing the proportion of purple loosestrife roots in the diet reduced adult weight and the proportion of larvae completing development, and increased development time; no larvae were able to complete development in root-free diet. With an increase in the number of larvae per cup, survival rates were reduced. The experiments revealed a female biased sex ratio: females consistently developed faster and were heavier than males. Incidence of adult deformities was consistently below 5%. Increased availability of adults for field release as a

  1. Comparison of application methods for suppressing the pecan weevil (Coleoptera: Curculionidae) with Beauveria bassiana under field conditions.

    PubMed

    Shapiro-Ilan, David I; Gardner, Wayne A; Cottrell, Ted E; Behle, Robert W; Wood, Bruce W

    2008-02-01

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecans. The entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin is pathogenic to C. caryae. One approach to managing C. caryae may be application of B. bassiana directed toward adult weevils as they emerge from the soil to attack nuts in the tree canopy. Our objective was to compare different application methods for suppression of C. caryae adults. Treatments included direct application of B. bassiana (GHA strain) to soil under the tree canopy, soil application followed by cultivation, soil application in conjunction with a cover crop (Sudan grass), direct application to the tree trunk, and application to the trunk with an UV radiation-protecting adjuvant. The study was conducted in a pecan orchard in Byron, GA, in 2005 and 2006. Naturally emerging C. caryae adults, caught after crawling to the trunk, were transported to the laboratory to determine percentage mortality and signs of mycosis. When averaged over the 15-d sampling period, weevil mortality and signs of mycosis were greater in all treatments than in the nontreated control in 2005 and 2006; >75% average mortality was observed with the trunk application both years and in the trunk application with UV protection in 2005. Results indicated trunk applications can produce superior efficacy relative to ground application, particularly if the ground application is followed by cultivation. Efficacy in the cover crop treatment, however, did not differ from other application approaches. Future research should focus on elucidating the causes for treatment differences we observed and the extent to which B. bassiana-induced C. caryae mortality reduces crop damage. PMID:18348807

  2. Susceptibility of different developmental stages of large pine weevil Hylobius abietis (Coleoptera: Curculionidae) to entomopathogenic fungi and effect of fungal infection to adult weevils by formulation and application methods.

    PubMed

    Ansari, Minshad A; Butt, Tariq M

    2012-09-15

    The large pine weevil, Hylobius abietis, is a major pest in European conifer forests causing millions of Euros of damage annually. Larvae develop in the stumps of recently felled trees; the emerging adults feed on the bark of seedlings and may kill them. This study investigated the susceptibility of different developmental stages of H. abietis to commercial and commercially viable isolates of entomopathogenic fungi, Metarhizium and Beauveria. All the developmental stages of H. abietis can be killed by Metarhizium robertsii, Metarhizium brunneum, and Beauveria bassiana. The most virulent isolate of M. robertsii ARSEF4556 caused 100% mortality of pupae, larvae and adults on day 4, 6 and 12, respectively. This strain was further tested against adult weevils in different concentrations (10(5)-10(8) conidia cm(-2) or ml(-1)) using two types of fungal formulation: 'dry' conidia and 'wet' conidia (suspended in 0.03% aq. Tween 80) applied on different substrates (tissue paper, peat and Sitka spruce seedlings). 'Dry' conidia were more effective than 'wet' conidia on tissue paper and on spruce or 'dry' conidia premixed in peat. The LC(50) value for 'dry' conidia of isolate ARSEF4556 was three folds lower than 'wet' conidia on tissue paper. This study showed that 'dry' conidia are more effective than 'wet' conidia, causing 100% adult mortality within 12 days. Possible strategies for fungal applications are discussed in light of the high susceptibility of larvae and pupae to fungal pathogen.

  3. Host PGRP gene expression and bacterial release in endosymbiosis of the weevil Sitophilus zeamais.

    PubMed

    Anselme, Caroline; Vallier, Agnès; Balmand, Séverine; Fauvarque, Marie-Odile; Heddi, Abdelaziz

    2006-10-01

    Intracellular symbiosis (endosymbiosis) with gram-negative bacteria is common in insects, yet little is known about how the host immune system perceives the endosymbionts and controls their growth and invasion without complete bacterial clearance. In this study, we have explored the expression of a peptidoglycan recognition protein gene of the weevil Sitophilus zeamais (wPGRP); an ortholog in Drosophila (i.e., PGRP-LB) was recently shown to downregulate the Imd pathway (A. Zaidman-Remy, M. Herve, M. Poidevin, S. Pili-Floury, M. S. Kim, D. Blanot, B. H. Oh, R. Ueda, D. Mengin-Lecreulx, and B. Lemaitre, Immunity 24:463-473, 2006). Insect challenges with bacteria have demonstrated that wPGRP is induced by gram-negative bacteria and that the level of induction depends on bacterial growth. Real-time reverse transcription-PCR quantification of the wPGRP gene transcript performed at different points in insect development has shown a high steady-state level in the bacteria-bearing organ (the bacteriome) of larvae and a high level of wPGRP up-regulation in the symbiotic nymphal phase. Concomitantly, during this stage fluorescence in situ hybridization has revealed an endosymbiont release from the host bacteriocytes. Together with the previously described high induction level of endosymbiont virulence genes at the nymphal phase (C. Dale, G. R. Plague, B. Wang, H. Ochman, and N. A. Moran, Proc. Natl. Acad. Sci. USA 99:12397-12402, 2002), these findings indicate that insect mutualistic relationships evolve through an interplay between bacterial virulence and host immune defense and that the host immunity engages the PGRP gene family in that interplay.

  4. Genetic Conservation of Phosphine Resistance in the Rice Weevil Sitophilus oryzae (L.).

    PubMed

    Nguyen, Tam T; Collins, Patrick J; Duong, Tu M; Schlipalius, David I; Ebert, Paul R

    2016-05-01

    High levels of resistance to phosphine in the rice weevil Sitophilus oryzae have been detected in Asian countries including China and Vietnam, however there is limited knowledge of the genetic mechanism of resistance in these strains. We find that the genetic basis of strong phosphine resistance is conserved between strains of S. oryzae from China, Vietnam, and Australia. Each of 4 strongly resistant strains has an identical amino acid variant in the encoded dihydrolipoamide dehydrogenase (DLD) enzyme that was previously identified as a resistance factor in Rhyzopertha dominica and Tribolium castaneum. The unique amino acid substitution, Asparagine > Threonine (N505T) of all strongly resistant S. oryzae corresponds to the position of an Asparagine > Histidine variant (N506H) that was previously reported in strongly resistant R. dominica. Progeny (F16 and F18) from 2 independent crosses showed absolute linkage of N505T to the strong resistance phenotype, indicating that if N505T was not itself the resistance variant that it resided within 1 or 2 genes of the resistance factor. Non-complementation between the strains confirmed the shared genetic basis of strong resistance, which was supported by the very similar level of resistance between the strains, with LC50 values ranging from 0.20 to 0.36 mg L(-1) for a 48-h exposure at 25 °C. Thus, the mechanism of high-level resistance to phosphine is strongly conserved between R. dominica, T. castaneum and S. oryzae. A fitness cost associated with strongly resistant allele was observed in segregating populations in the absence of selection.

  5. Genetic Conservation of Phosphine Resistance in the Rice Weevil Sitophilus oryzae (L.).

    PubMed

    Nguyen, Tam T; Collins, Patrick J; Duong, Tu M; Schlipalius, David I; Ebert, Paul R

    2016-05-01

    High levels of resistance to phosphine in the rice weevil Sitophilus oryzae have been detected in Asian countries including China and Vietnam, however there is limited knowledge of the genetic mechanism of resistance in these strains. We find that the genetic basis of strong phosphine resistance is conserved between strains of S. oryzae from China, Vietnam, and Australia. Each of 4 strongly resistant strains has an identical amino acid variant in the encoded dihydrolipoamide dehydrogenase (DLD) enzyme that was previously identified as a resistance factor in Rhyzopertha dominica and Tribolium castaneum. The unique amino acid substitution, Asparagine > Threonine (N505T) of all strongly resistant S. oryzae corresponds to the position of an Asparagine > Histidine variant (N506H) that was previously reported in strongly resistant R. dominica. Progeny (F16 and F18) from 2 independent crosses showed absolute linkage of N505T to the strong resistance phenotype, indicating that if N505T was not itself the resistance variant that it resided within 1 or 2 genes of the resistance factor. Non-complementation between the strains confirmed the shared genetic basis of strong resistance, which was supported by the very similar level of resistance between the strains, with LC50 values ranging from 0.20 to 0.36 mg L(-1) for a 48-h exposure at 25 °C. Thus, the mechanism of high-level resistance to phosphine is strongly conserved between R. dominica, T. castaneum and S. oryzae. A fitness cost associated with strongly resistant allele was observed in segregating populations in the absence of selection. PMID:26774057

  6. Evaluation and modeling of synergy to pheromone and plant kairomone in American palm weevil

    PubMed Central

    2011-01-01

    Background Many behavioral responses to odors are synergistic, particularly in insects. In beetles, synergy often involves a pheromone and a plant odor, and pest management relies on them for the use of combined lures. To investigate olfactory synergy mechanisms, we need to distinguish synergistic effects from additive ones, when all components of the mixture are active. Results As versatile tools and procedures were not available, we developed a bioassay, and a mathematical model to evaluate synergy between aggregation pheromone (P) and host plant odors (kairomone: K) in the American palm weevil, a pest insect showing enhanced responses to P+K mixtures. Responses to synthetic P and natural K were obtained using a 4-arm olfactometer coupled to a controlled volatile delivery system. We showed that: (1) Response thresholds were ca. 10 and 100 pg/s respectively for P and K. (2) Both stimuli induced similar maximum response. (3) Increasing the dose decreased the response for P to the point of repellence and maintained a maximum response for K. (4) P and K were synergistic over a 100-fold range of doses with experimental responses to P+K mixtures greater than the ones predicted assuming additive effects. Responses close to maximum were associated with the mixture amounts below the response threshold for both P and K. Conclusion These results confirm the role of olfactory synergy in optimizing active host-plant localization by phytophagous insects. Our evaluation procedure can be generalized to test synergistic or inhibitory integrated responses of various odor mixtures for various insects. PMID:21463509

  7. Colonization history, ecological shifts and diversification in the evolution of endemic Galápagos weevils.

    PubMed

    Sequeira, A S; Lanteri, A A; Albelo, L Roque; Bhattacharya, S; Sijapati, M

    2008-02-01

    Mitochondrial DNA sequence data were obtained for eight species of flightless Galapaganus endemic weevils and one winged close relative in order to study their colonization history and modes of diversification in the Galápagos Archipelago. Contrary to most other insular radiations, the phylogeny estimates we recovered for Galapaganus do not follow the progression rule of island biogeography. The penalized likelihood age estimates of colonization of the archipelago exceed the age of the emerged islands and underscore the potential role of now sunken seamounts for the early evolution of Galapaganus. The phylogeny proposes one intra-island origin for Galapaganus endemics, but monophyly tests suggest a larger contribution of in-situ speciation on older islands. Generalist habitat preferences were reconstructed as ancestral while shifts to highland habitats were reconstructed as having evolved independently on different islands. Magnitudes and patterns of diversification rate were found to differ between older and younger islands. Our analyses reveal that the colonization sequence of islands and timing of colonization of Galapaganus could be linked with the geological and volcanic history of the islands in a rather complex scenario. Even though most islands appear to have been colonized soon after their emergence, there are notable deviations from the pattern of sequential colonization expected under the progression rule when considering only the extant emerged islands. Patterns of diversification rate variation on older and younger islands correspond to the volcanic activity or remnants of such activity, while the pattern of independent evolution of restricted habitat preferences in different islands suggests that habitat shifts could also have contributed to species diversity in Galapaganus.

  8. Are flightless Galapaganus weevils older than the Galápagos Islands they inhabit?

    PubMed

    Sequeira, A S; Lanteri, A A; Scataglini, M A; Confalonieri, V A; Farrell, B D

    2000-07-01

    The 15 species in the weevil genus Galapaganus Lanteri 1992 (Entiminae: Curculionidae: Coleoptera) are distributed on coastal Perú and Ecuador and include 10 flightless species endemic to the Galápagos islands. These beetles thus provide a promising system through which to investigate the patterns and processes of evolution on Darwin's archipelago. Sequences of the mtDNA locus encoding cytochrome oxidase subunit I (COI) were obtained from samples of seven species occurring in different ecological zones of the oldest south-eastern islands: San Cristóbal, Española and Floreana, and the central island Santa Cruz. The single most parsimonious tree obtained shows two well-supported clades that correspond to the species groups previously defined by morphological characters. Based on a mtDNA clock calibrated for arthropods, the initial speciation separating the oldest species, G. galapagoensis (Linell) on the oldest island, San Cristóbal, from the remaining species in the Galápagos occurred about 7.2 Ma. This estimate exceeds geological ages of the extant emerged islands, although it agrees well with molecular dating of endemic Galápagos iguanas, geckos and lizards. An apparent explanation for the disagreement between geological and molecular time-frames is that about 7 Ma there were emerged islands which subsequently disappeared under ocean waters. This hypothesis has gained support from the recent findings of 11-Myr-old submarine seamounts (sunken islands), south-east of the present location of the archipelago. Some species within the darwini group may have differentiated on the extant islands, 1-5 Ma.

  9. Registration of AO-1012-29-3-3A red kidney bean germplasm line with bean weevil, BCMV and BCMNV resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV) are important seed-borne diseases of dry bean (Phaseolus vulgaris L.) in the Americas and Africa. The bean weevil (Acanthoscelides obtectus Say) is an aggressive post-harvest pest of the common bean. The development of bea...

  10. Identification of genome regions controlling cotyledon, pod wall/seed coat and pod wall resistance to pea weevil through QTL mapping.

    PubMed

    Aryamanesh, N; Zeng, Y; Byrne, O; Hardie, D C; Al-Subhi, A M; Khan, T; Siddique, K H M; Yan, G

    2013-11-15

    Pea weevil, Bruchus pisorum, is one of the limiting factors for field pea (Pisum sativum) cultivation in the world with pesticide application the only available method for its control. Resistance to pea weevil has been found in an accession of Pisum fulvum but transfer of this resistance to cultivated pea (P. sativum) is limited due to a lack of easy-to-use techniques for screening interspecific breeding populations. To address this problem, an interspecific population was created from a cross between cultivated field pea and P. fulvum (resistance source). Quantitative trait locus (QTL) mapping was performed to discover the regions associated with resistance to cotyledon, pod wall/seed coat and pod wall resistance. Three major QTLs, located on linkage groups LG2, LG4 and LG5 were found for cotyledon resistance explaining approximately 80 % of the phenotypic variation. Two major QTLs were found for pod wall/seed coat resistance on LG2 and LG5 explaining approximately 70 % of the phenotypic variation. Co-linearity of QTLs for cotyledon and pod wall/seed coat resistance suggested that the mechanism of resistance for these two traits might act through the same pathways. Only one QTL was found for pod wall resistance on LG7 explaining approximately 9 % of the phenotypic variation. This is the first report on the development of QTL markers to probe Pisum germplasm for pea weevil resistance genes. These flanking markers will be useful in accelerating the process of screening when breeding for pea weevil resistance.

  11. An experimental study of the interaction between the dwarf palm ( Chamaerops humilis) and its floral visitor Derelomus chamaeropsis throughout the life cycle of the weevil

    NASA Astrophysics Data System (ADS)

    Anstett, Marie Charlotte

    1999-09-01

    Palm pollination can be quite diverse but has been poorly studied. This paper describes the life cycle of Derelomus chamaeropsis, a Coleoptera that inhabits the inflorescences of the Mediterranean dwarf palm Chamaerops humilis. D. chamaeropsis is specific to Chamaerops inflorescences, where it eats pollen and the rachis of inflorescences on pistillate plants. They usually lay eggs only on staminate inflorescences where larvae develop and bore into the inflorescence rachis. Larvae do not develop on pistillate inflorescences, except for cases with almost no fruit development. Pistillate plants can thus protect themselves from weevil predation. When visiting pistillate inflorescences, weevils can feed on rachis but usually do not find the brood place reward. Pollination is thus by deceit and weevils should be selected to avoid pistillate inflorescences. D. chamaeropsis pupate within the rachis of staminate inflorescences, but disperse before collecting pollen, thus staminate plants do not have an individual advantage in breeding weevils. However, because larvae develop on dead tissues, the costs of larval development are likely to be low for the plant. This study provides a new example of pollination symbiosis where the pollinator develops on the plant it pollinates, and illustrates how the evolutionary functioning of such relationships can be diverse.

  12. Trapping sweetpotato weevil, Cylas formicarius elegantulus (Coleoptera: Brentidae), with high doses of sex pheromone: Catch enhancement and weathering rate in Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato, Ipomoea batatas (L.) Lamarck, one of the top ten staple crops produced worldwide, has increased in production in Hawaii in recent years. The sweetpotato weevil, Cylas formicarius elegantulus (Summers)(Coleoptera: Brentidae), is a major economic and quarantine pest of sweetpotato in Hawa...

  13. Electroantennographic responses of the lesser chestnut weevil curculio sayi (Coleoptera: Curculionidae) to volatile organic compounds identified from chestnut reproductive plant tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary insect pest of the developing chestnut industry in the central United States is the lesser chestnut weevil, Curculio sayi (Gyllenhal), which is a specialist on only Castanea trees. Recent research has shown this insect is attracted to and feeds upon the reproductive tissues of the chestn...

  14. Loss of phytotelmata due to an invasive bromeliad-eating weevil and its potential effects on faunal diversity and biogeochemical cycles

    NASA Astrophysics Data System (ADS)

    Cooper, Teresa M.; Frank, J. Howard; Cave, Ronald D.

    2014-01-01

    Epiphytic tank bromeliads are important ecosystem engineers because they form phytotelmata that create habitat, increase species richness and abundance, create water sources and nutrient reservoirs in the canopy, and collect and redirect nutrients in forest ecosystems. Native bromeliad populations have been devastated in Florida (USA) because an invasive bromeliad-eating weevil (Metamasius callizona) has been destroying the plants. Tillandsia utriculata is a tank bromeliad that was once widespread from central to south Florida. Its populations have been hit hard by the weevil and are declining rapidly. This study quantifies the mortality rate caused by the weevil in a population of T. utriculata at the Enchanted Forest Sanctuary in central Florida and estimates the associated loss of phytotelmata. Estimations of phytotelmata were calculated for the T. utriculata baseline population, the population at 6 months into the study when 87% of the population was destroyed, and at the end of the study when less than 3% of the bromeliad population remained (99% of all deaths were caused by the weevil). The baseline population contained 16,758 L of water. At six months, there were 3180 L, and at the end of the study, there were 408 L. The loss of phytotelmata results in the loss of habitat, a decrease in biological diversity, and altered water and nutrient cycles and availability.

  15. Dielectric properties of cowpea weevil, black eyed peas and mung beans with respect to the development of radio frequency heat treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In developing radio frequency (RF) and microwave (MW) disinfestation treatments for chickpeas and lentils, large amounts of product infested with cowpea weevil must be treated to validate treatment efficacy. To accomplish this, black-eyed peas and mung beans are being considered for use as surrogate...

  16. Integrated biological control of water hyacinths, Eichhornia crassipes by a novel combination of grass carp, Ctenopharyngodon idella (Valenciennes, 1844), and the weevil, Neochetina spp.

    NASA Astrophysics Data System (ADS)

    Gopalakrishnan, Ayyaru; Rajkumar, Mayalagu; Sun, Jun; Parida, Ajay; Venmathi Maran, Balu Alagar

    2011-01-01

    The efficacy of grass carp Ctenopharyngodon idella (Cyprinidae) and weevils Neochetina spp. (Curculionidae) to control the aquatic weed, water hyacinth, is investigated in a square net cage (happas) setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within 110 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed biomass is reduced from 5 kg (day 1) to 0.33 kg (day 110) when exposed to grass carp and weevils. The number of plants is reduced to 0.75 in grass carp and weevil exposed happas, while it is 741.5 in the control. The mean number of leaves per plant is also reduced. In addition, the chlorophyll a and b are significantly reduced in happas exposed to the combination of fish and insects when compared to the other treatments. Based on the results of this study, we consider the combined use of grass carp and weevils to be more efficient and sustainable for managing water hyacinths than the use of these organisms individually.

  17. Recent developments in the use of acoustic sensors and signal processing tools to target early infestations of Red Palm Weevil in agricultural environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much of the damage caused by red palm weevil larvae to date palms, ornamental palms, and palm offshoots could be mitigated by early detection and treatment of infestations. Acoustic technology has potential to enable early detection, but the short, high-frequency sound impulses produced by red palm ...

  18. Recent developments in the use of acoustic sensors and signal processing tools to target early infestations of red palm weevil (Coleopter: Curculionidae) in agricultural environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much of the damage caused by red palm weevil larvae to date palms, ornamental palms, and palm offshoots could be mitigated by early detection and treatment of infestations. Acoustic technology has potential to enable early detection, but the short, high-frequency sound impulses produced by red palm ...

  19. Abundance and Frequency of the Asiatic Oak Weevil (Coleoptera: Curculionidae) and Defoliation on American, Chinese, and Hybrid Chestnut (Castanea).

    PubMed

    Case, Ashley E; Mayfield, Albert E; Clark, Stacy L; Schlarbaum, Scott E; Reynolds, Barbara C

    2016-01-01

    The Asiatic oak weevil, Cyrtepistomus castaneus Roelofs (Coleoptera: Curculionidae), is a nonnative defoliator of trees in the Fagaceae family in the United States but has not been studied on Castanea species in the southern Appalachian Mountains. Planted trees of Castanea dentata (Marsh.) Borkh. (Fagales: Fagaceae), Castanea mollissima Blume (Fagales: Fagaceae), and four hybrid breeding generations were evaluated in 2012 for insect defoliation and C. castaneus abundance and frequency. Defoliation was visually assessed throughout the growing season at two sites in the southern Appalachian Mountains (western North Carolina and eastern Tennessee). C. castaneus abundance and frequency were monitored on trees using beat sheets and emergence was recorded from ground traps. Asiatic oak weevils were more abundant and more frequently collected on American chestnut (Ca. dentata) and its most closely related BC3F3 hybrid generation than on the Asian species Ca. mollissima. In most months, C. castaneus colonization of hybrid generations was not significantly different than colonization of parental species. Frequency data for C. castaneus suggested that adults were distributed relatively evenly throughout the study sites rather than in dense clusters. Emergence of C. castaneus was significantly higher under a canopy dominated by Quercus species than under non-Quercus species or open sky. C. castaneus emergence began in May and peaked in late June and early July. These results may be useful for resource managers trying to restore blight-resistant chestnut to the Southern Appalachians while minimizing herbivory by insect pests. PMID:27001964

  20. Morphology of salivary gland and distribution of dopamine and serotonin on red palm weevil (RPW), Rhynchophorus ferrugineus (Coleoptera: Curculionidae)

    NASA Astrophysics Data System (ADS)

    Hidayah, A. S. Nurul; Wahida, O. Nurul; Shafinaz, M. N. Norefrina; Idris, A. G.

    2013-11-01

    The Red Palm Weevil (RPW), Rhynchophorus ferrugineus (Olivier, 1790) is insect pest to plants of the family Palmaceae. No study has been reported on the digestive mechanism of Red Palm Weevil (RPW). Salivary glands are responsible in the feeding regulation of insect while serotonin and dopamine play a significant role in the regulation of this gland. It is great to see the morphology of the salivary gland and how dopamine and serotonin possibly play their role in this gland. Two variation of RPW, striped and spotted RPW were chosen. The morphology of the gland of both RPW variants examined by using light microscopy was found to be a tubular type. Immunohistochemical analysis conducted showed that serotonin and dopamine in both variations did not innervate the glands suggesting they are not act as neurotransmitter. However, it can be detected on few areas within the glands. This suggests that serotonin and dopamine may act as a hormone because there is no evidence on the nerve fibers. The role of these biogenic amines in the salivary gland of RPW needs further investigation. Hopefully the data would help in understanding the mechanism of salivary glands control by biogenic amines in RPW specifically and insects with sucking mouthpart generally.

  1. Abundance and Frequency of the Asiatic Oak Weevil (Coleoptera: Curculionidae) and Defoliation on American, Chinese, and Hybrid Chestnut (Castanea)

    PubMed Central

    Case, Ashley E.; Mayfield, Albert E.; Clark, Stacy L.; Schlarbaum, Scott E.; Reynolds, Barbara C.

    2016-01-01

    The Asiatic oak weevil, Cyrtepistomus castaneus Roelofs (Coleoptera: Curculionidae), is a nonnative defoliator of trees in the Fagaceae family in the United States but has not been studied on Castanea species in the southern Appalachian Mountains. Planted trees of Castanea dentata (Marsh.) Borkh. (Fagales: Fagaceae), Castanea mollissima Blume (Fagales: Fagaceae), and four hybrid breeding generations were evaluated in 2012 for insect defoliation and C. castaneus abundance and frequency. Defoliation was visually assessed throughout the growing season at two sites in the southern Appalachian Mountains (western North Carolina and eastern Tennessee). C. castaneus abundance and frequency were monitored on trees using beat sheets and emergence was recorded from ground traps. Asiatic oak weevils were more abundant and more frequently collected on American chestnut (Ca. dentata) and its most closely related BC3F3 hybrid generation than on the Asian species Ca. mollissima. In most months, C. castaneus colonization of hybrid generations was not significantly different than colonization of parental species. Frequency data for C. castaneus suggested that adults were distributed relatively evenly throughout the study sites rather than in dense clusters. Emergence of C. castaneus was significantly higher under a canopy dominated by Quercus species than under non-Quercus species or open sky. C. castaneus emergence began in May and peaked in late June and early July. These results may be useful for resource managers trying to restore blight-resistant chestnut to the Southern Appalachians while minimizing herbivory by insect pests. PMID:27001964

  2. Abundance and Frequency of the Asiatic Oak Weevil (Coleoptera: Curculionidae) and Defoliation on American, Chinese, and Hybrid Chestnut (Castanea).

    PubMed

    Case, Ashley E; Mayfield, Albert E; Clark, Stacy L; Schlarbaum, Scott E; Reynolds, Barbara C

    2016-01-01

    The Asiatic oak weevil, Cyrtepistomus castaneus Roelofs (Coleoptera: Curculionidae), is a nonnative defoliator of trees in the Fagaceae family in the United States but has not been studied on Castanea species in the southern Appalachian Mountains. Planted trees of Castanea dentata (Marsh.) Borkh. (Fagales: Fagaceae), Castanea mollissima Blume (Fagales: Fagaceae), and four hybrid breeding generations were evaluated in 2012 for insect defoliation and C. castaneus abundance and frequency. Defoliation was visually assessed throughout the growing season at two sites in the southern Appalachian Mountains (western North Carolina and eastern Tennessee). C. castaneus abundance and frequency were monitored on trees using beat sheets and emergence was recorded from ground traps. Asiatic oak weevils were more abundant and more frequently collected on American chestnut (Ca. dentata) and its most closely related BC3F3 hybrid generation than on the Asian species Ca. mollissima. In most months, C. castaneus colonization of hybrid generations was not significantly different than colonization of parental species. Frequency data for C. castaneus suggested that adults were distributed relatively evenly throughout the study sites rather than in dense clusters. Emergence of C. castaneus was significantly higher under a canopy dominated by Quercus species than under non-Quercus species or open sky. C. castaneus emergence began in May and peaked in late June and early July. These results may be useful for resource managers trying to restore blight-resistant chestnut to the Southern Appalachians while minimizing herbivory by insect pests.

  3. Repeated Cold Exposure Effects on Mortality and Feeding Activity of the Salvinia Weevil, Cyrtobagous salviniae (Coleoptera: Curculionidae).

    PubMed

    Obeysekara, Piyumi T; Knutson, Allen; Mukherjee, Abhishek; Heinz, Kevin M

    2015-12-01

    Biological control of the aquatic fern, Salvinia molesta D. S. Mitchell, by Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae), in temperate regions has been less reliable relative to tropical and subtropical regions. High mortality of overwintering adults is presumed to be an important factor. At temperate sites, overwintering adult C. salviniae may experience multiple exposures to low temperatures that could compound to lethal levels. We examined the effects of repeated cold exposure (RCE) on the overwintering mortality and feeding rate of adult C. salviniae. Mortality rate of adults following exposure to 2, 4, and 6 cycles of RCE was 22, 70 and 82%, respectively. Mortality in the RCE treatment was similar to that in the matched-cold treatment for 2 and 6 cycles but was significantly less than in the matched-cold treatment for the 4 cycles. The relationship between the number of RCE and adult mortality rate was modeled and model results were compared to adult survival of caged weevils during four winters on two lakes in northeast Texas. Also, the feeding activity of adult weevils surviving RCE declined following exposure to 4 and 6 cycles of RCE. These results provide insight into how cold impacts overwintering survival of C. salviniae and should assist in anticipating the need for inoculative releases of C. salviniae the following spring to achieve consistent biological control of S. molesta at temperate locales. PMID:26314025

  4. The evolutionary history of maternal plant-manipulation and larval feeding behaviours in attelabid weevils (Coleoptera; Curculionoidea).

    PubMed

    Kobayashi, Chisato; Okuyama, Yudai; Kawazoe, Kazuhide; Kato, Makoto

    2012-08-01

    Attelabid weevils manipulate specific structures of their host plants in a species-specific manner, e.g., cutting a shoot, cutting a leaf, rolling a leaf, or constructing sophisticated wrapped leaf rolls, presumably to secure the survivorship of eggs or larvae. To depict the evolutionary history of maternal plant-manipulation behaviours and larval feeding strategies of the family Attelabidae, molecular phylogenetic analyses were conducted by sequencing the nuclear 18S and 28S ribosomal DNA and the mitochondrial cytochrome oxidase subunit I genes. Our analyses indicated that the attelabid weevils form a monophyletic group, and that maternal plant-cutting behaviour originated in a common ancestor of Attelabidae, but was subsequently lost in several lineages. Monophyly of the subfamily Attelabinae was also recovered with high support, but the subfamily Rhynchitinae was not recovered as monophyletic. By employing maximum-likelihood-based ancestral state reconstructions, larval leaf-blade feeding was inferred to have evolved from boring of cut shoots/petioles. Moreover, maternal leaf-rolling behaviours likely originated independently in the Attelabinae and Byctiscini lineages, and in several Deporaini lineages. As the sophisticated behaviours constructing wrapped leaf rolls of Attelabinae originated only once and has not been lost from the lineage, these complex and innovative behaviours may have contributed to the success and diversification of the lineage.

  5. Sunflower stem weevil and its larval parasitoids in native sunflowers: is parasitoid abundance and diversity greater in the U.S. Southwest?

    PubMed

    Ode, Paul J; Charlet, Laurence D; Seiler, Gerald J

    2011-02-01

    Classical biological control programs often target a pest's region of origin as a likely source for new biological control agents. Here, we use this approach to search for biological control agents of the sunflower stem weevil (Cylindrocopturus adspersus LeConte), an economically important pest of commercial sunflower. We conducted surveys of weevil natural enemy diversity and abundance across a transect running from the northern Great Plains to the southwestern U.S. (the presumed area of endemism of annual sunflower species in the genus Helianthus). Accordingly, natural enemy diversity and abundance were expected to be greater in the southwestern U.S. C. adspersus and their larval parasitoids were collected from stems of four native sunflower species (Helianthus annuus, H. nuttallii, H. pauciflorus, and H. petiolaris) from 147 sites across eight states. Native H. annuus constituted the majority of the sunflower populations. Mean weevil densities were significantly higher in sunflower stalks that were larger in diameter. Mean weevil densities within sites did not differ across the range of longitudes and latitudes sampled. After accounting for the effects of stalk diameter and location, weevil densities did not differ among the four sunflower species nor did they differ as a function of elevation. C. adspersus in H. annuus and H. petiolaris were attacked by seven species of parasitoids. No parasitoids were found attacking C. adspersus in H. nuttallii or H. pauciflorus stalks. C. adspersus were twice as likely to be attacked by a parasitoid when feeding on H. petiolaris than H. annuus. Furthermore, the likelihood that C. adspersus would be parasitized decreased with increasing elevation and increasing stem diameters. All parasitoid species have been previously reported attacking C. adspersus larvae in cultivated sunflower. Species richness was less diverse in these collections than from previous studies of cultivated sunflower. Our findings suggest that the species

  6. Growth and development of the pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae), on bolls of cotton grown in enriched carbon dioxide atmospheres

    SciTech Connect

    Akey, D.H.; Kimball, B.A.; Mauney, J.R.

    1988-06-01

    The pink bollworm, Pectinophora gossypiella (Saunders), was reared on the bolls of cotton plants grown in CO/sub 2/-enriched (649 ..mu..l/liter) and ambient CO/sub 2/ (371 ..mu..l/liter) chambers and in two open field plots, one with free-air CO/sub 2/ enrichment (522 ..mu..l/liter) and one without enrichment (ambient CO/sub 2/, 360 ..mu..l/liter). The effects of increased CO/sub 2/ levels on growth and development were examined. There was no difference in pupal weights of pink bollworm raised on CO/sub 2/-enriched cotton compared with those raised on ambient CO/sub 2/ cotton (26.80 versus 26.64 mg, respectively). Also, there was no difference in developmental time (21-27 d). Analysis of percent seed damage by larvae showed no differences between CO/sub 2/-enriched and ambient CO/sub 2/ cotton. These results were attributed to the nutritional qualities of the seed remaining the same (specifically the carbon/nitrogen ratio) despite CO/sub 2/ and photosynthetic changes in the plant.

  7. Bioaccumulation of mercury and its effect on protein metabolism of the water hyacinth weevil Neochetina eichhornae (Warner)

    SciTech Connect

    Hussain, Md.S.; Jamil, K. )

    1990-08-01

    Water hyacinth growth is kept under control by the week eating weevils, Neochetina eichhornae (Warner) and N. bruchi (Hustache). Water hyacinth is generally considered an aquatic weed because it clogs waterways, although it has recently been evaluated as a potential biological filter for sewage effluents. Water hyacinth plants are continuously subjected to contamination by mercury and other heavy metals from industrial effluents and fertilizer impurities. Little is known about the interaction of heavy metals/plants/insects. Aminotransferases are generally considered as indices for metabolic disturbances during Hg exposure. These enzymes are key enzymes for transamination, i.e., transfer of amino group from amino acid to keto acids which are ubiquitous in insects. The objective of the present study was to examine the bioaccumulation of mercury through the food chain in Neochetina eichhornae and its impact on protein metabolism.

  8. Landscape Connectivity Shapes the Spread Pattern of the Rice Water Weevil: A Case Study from Zhejiang, China

    NASA Astrophysics Data System (ADS)

    Wang, Zhengjun; Wu, Jianguo; Shang, Hanwu; Cheng, Jiaan

    2011-02-01

    The spread of invasive species is a complex ecological process that is affected by both the biology of the species and the spatial structure of a landscape. The rice water weevil ( Lissorhoptrus oryzophilus Kuschel), a notorious crop pest found in many parts of the world, is one of the most devastating invasive species in China, and has caused enormous economic losses and ecological damage. Little is known, however, as to how habitat and landscape features affect the spatial spread of this pest. Thus, the main goal of this study was to investigate the relationship between the observed spread pattern of L. oryzophilus and landscape structural factors in Zhejiang Province, China between 1993 and 2001. We quantified the invasive spread of the weevil in terms of both the proportion of infected area and spread distance each year as well as landscape structure and connectivity of rice paddies with landscape metrics. Our results showed that the spread of L. oryzophilus took place primarily in the southwest-northeast direction along coastal areas at a speed of about 36 km per year. The composition and spatial arrangement of landscape elements were key determinants of this unique spread pattern. In particular, the connectivity of early rice paddies was crucial for the invasive spread while other factors such as meteorological and geographical conditions may also have been relevant. To control the spread of the pest, we propose four management measures: (1) to implement a landscape-level planning scheme of cropping systems to minimize habitat area and connectivity for the pest, (2) to reduce the source populations at a local scale using integrated control methods, (3) to monitor and report invasive spread in a timely manner, and (4) to strengthen the quarantine system. To be most effective, all four management measures need to be implemented together through an integrated, multi-scaled approach.

  9. Pepper Weevil (Coleoptera: Curculionidae) Preferences for Specific Pepper Cultivars, Plant Parts, Fruit Colors, Fruit Sizes, and Timing.

    PubMed

    Seal, Dakshina R; Martin, Cliff G

    2016-03-04

    Peppers (Capsicum spp.) are an important crop in the USA, with about 32,000 ha cultivated in 2007, which resulted in $588 million in farm revenue. The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is the most troublesome insect pest of peppers in the southern United States. It is therefore urgent to find different vulnerabilities of pepper cultivars, fruit and plants parts, fruit colors and sizes, and timing to infestation by A. eugenii. Also relevant is testing whether fruit length and infestation state affect fruit numbers, weights, and proportions of fruit that are infested. Counts of A. eugenii adults and marks from oviposition and feeding suggested that C. chinense Jacquin "Habanero" was least susceptible, and C. annuum L. cultivars "SY" and "SR" were most susceptible. Comparison of plant parts and fruit sizes revealed that A. eugenii preferred the peduncle, calyx, and top of pepper fruits over the middle, bottom, leaves, or remainder of flowers. Anthonomus eugenii does not discriminate between green or yellow fruit color nor vary diurnally in numbers. Based on adult counts, medium to extra-large fruits (≥1.5 cm long) attracted more weevils than small fruits (<1.5 cm). However based on proportions of fruit numbers or fruit weights that were infested, there were no differences between large and small fruits. Choice of pepper cultivar can thus be an important part of an IPM cultural control program designed to combat A. eugenii by reduced susceptibility or by synchronous fruit drop of infested fruits. Our results are potentially helpful in developing scouting programs including paying particular attention to the preferred locations of adults and their sites of feeding and oviposition on the fruit. The results also suggested the potential value of spraying when the fruits are still immature to prevent and control infestation.

  10. Resynthesized lines and cultivars of Brassica napus L. provide sources of resistance to the cabbage stem weevil ( Ceutorhynchus pallidactylus (Mrsh.)).

    PubMed

    Eickermann, M; Ulber, B; Vidal, S

    2011-06-01

    The cabbage stem weevil (Ceutorhynchus pallidactylus (Mrsh.)) (Col., Curculionidae) is a serious pest of winter oilseed rape (Brassica napus L. var. oleifera Metzg.) in central and northern Europe. Although host-plant resistance is a key tool in integrated pest management systems, resistant genotypes are not yet available for this species. Resynthesized rapeseed lines (B. oleracea L.×B. rapa L.) are broadening the genetic diversity and might have potential as sources of resistance to pest insects. The host quality, of nine resynthesized rapeseed lines and six genotypes of B. napus to cabbage stem weevil, was evaluated in laboratory screening tests and in a semi-field experiment. In dual-choice oviposition tests, female C. pallidactylus laid significantly fewer eggs on five resyntheses and on swede cv 'Devon Champion' than on the moderately susceptible oilseed rape cv 'Express', indicating a lower host quality of these genotypes. Results of laboratory screenings were confirmed in a semi-field experiment, in which twelve genotypes were exposed to C. pallidactylus females. The number of larvae was significantly lower in two resyntheses and in cv 'Devon Champion' than in oilseed rape cv WVB 9. The total, as well as individual, glucosinolate (GSL) content in the leaves differed substantially among the genotypes tested. The amount of feeding by larvae of C. pallidactylus, as measured by a stem-injury coefficient, was positively correlated with the indolyl GSL compounds 3-indolylmethyl and 4-methoxy-3-indolylmethyl, and with the aromatic GSL 2-phenylethyl, whereas it was negatively correlated with 4-hydroxy-3-indolylmethyl. Thus, the composition and concentration of GSL compounds within the plant tissue might be a key factor in breeding for pest resistance in oilseed rape.

  11. Spinosad Induces Antioxidative Response and Ultrastructure Changes in Males of Red Palm Weevil Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae)

    PubMed Central

    Abdelsalam, Salaheldin A.; Alzahrani, Abdullah M.; Elmenshawy, Omar M.; Abdel-Moneim, Ashraf M.

    2016-01-01

    The red palm weevil, Rhynchophorus ferrugineus, is of great concern worldwide, especially in the Middle East, where dates are a strategic crop. Despite their ecological hazard, insecticides remain the most effective means of control. A bioinsecticide of bacterial origin, spinosad is effective against several pests, and its efficacy against male R. ferrugineus was assessed in the present study. The antioxidative responses of key enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) to spinosad were investigated in the midgut and testes, and the effects of this insecticide on the cell ultrastructure of the midgut, Malpighian tubules, and testes were also determined. The lethal concentration 50 of spinosad was measured at 58.8 ppm, and the insecticide inhibited the activities of CAT, SOD, and GST in the midgut. However, no significant changes in the activities of these enzymes were observed in the testes. Spinosad treatment resulted in concentration-dependent changes in the cellular organelles of the midgut, Malpighian tubules, and testes of R. ferrugineus, and some of these effects were similar to those exerted by other xenobiotics. However, specific changes were observed as a result of spinosad treatment, including an increase in the number and size of concretions in Malpighian tubule cells and the occasional absence of the central pair of microtubules in the axonemes of sperm tails. This study introduces spinosad for potential use as an insecticide within an integrated control program against male red palm weevils. Additionally, the study provides biochemical and ultrastructural evidence for use in the development of bioindicators.

  12. Pepper Weevil (Coleoptera: Curculionidae) Preferences for Specific Pepper Cultivars, Plant Parts, Fruit Colors, Fruit Sizes, and Timing

    PubMed Central

    Seal, Dakshina R.; Martin, Cliff G.

    2016-01-01

    Peppers (Capsicum spp.) are an important crop in the USA, with about 32,000 ha cultivated in 2007, which resulted in $588 million in farm revenue. The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is the most troublesome insect pest of peppers in the southern United States. It is therefore urgent to find different vulnerabilities of pepper cultivars, fruit and plants parts, fruit colors and sizes, and timing to infestation by A. eugenii. Also relevant is testing whether fruit length and infestation state affect fruit numbers, weights, and proportions of fruit that are infested. Counts of A. eugenii adults and marks from oviposition and feeding suggested that C. chinense Jacquin “Habanero” was least susceptible, and C. annuum L. cultivars “SY” and “SR” were most susceptible. Comparison of plant parts and fruit sizes revealed that A. eugenii preferred the peduncle, calyx, and top of pepper fruits over the middle, bottom, leaves, or remainder of flowers. Anthonomus eugenii does not discriminate between green or yellow fruit color nor vary diurnally in numbers. Based on adult counts, medium to extra-large fruits (≥1.5 cm long) attracted more weevils than small fruits (<1.5 cm). However based on proportions of fruit numbers or fruit weights that were infested, there were no differences between large and small fruits. Choice of pepper cultivar can thus be an important part of an IPM cultural control program designed to combat A. eugenii by reduced susceptibility or by synchronous fruit drop of infested fruits. Our results are potentially helpful in developing scouting programs including paying particular attention to the preferred locations of adults and their sites of feeding and oviposition on the fruit. The results also suggested the potential value of spraying when the fruits are still immature to prevent and control infestation. PMID:26959066

  13. Effect of Selected Volatiles on Two Stored Pests: The Fungus Fusarium verticillioides and the Maize Weevil Sithophilus zeamais.

    PubMed

    Zunino, María P; Herrera, Jimena M; Pizzolitto, Romina P; Rubinstein, Héctor R; Zygadlo, Julio A; Dambolena, José S

    2015-09-01

    New agronomic practices and technology enabled Argentina a larger production of cereal grains, reaching a harvest yield of 26.5 million metric tons of maize, of which, about 40% was exported. However, much of the maize production is lost annually by the attack of fungi and insects (2.6 million tons). In this study, the antifungal effect of selected volatiles on Fusarium verticillioides, its mycotoxin production, and the repellent and insecticidal activities against the weevill Sithophilus zeamais, an insect vector of F. verticillioides, were evaluated. The compounds tested were (2E)-2-hexenal, (2E)-2-nonenal, (2E,6Z)-2,6-nonadienal, 1-pentanol, 1-hexanol, 1-butanol, 3-methyl-1-butanol, pentanal, 2-decanone, and 3-decanone, which occur in the blend of volatile compounds emitted by various cereal grains. The most active antifungals were the aldehydes (2E)-2-nonenal, (2E)-2-hexenal, and (2E,6Z)-2,6-nonadienal (minimum inhibitory concentration values of <0.03, 0.06, and 0.06 mM, respectively). The occurrence of fumonisin B1 also was prevented because these compounds completely inhibited fungal growth. The best insecticidal fumigant activities against the maize weevil were shown by 2-decanone and 3-decanone (lethal concentration ≤ 54.6 μL/L (<0.28 mM)). Although, all tested compounds showed repellent activity against S. zeamais at a concentration of 4 μL/L, (2E,6Z)-2,6-nonadienal was the most active repellent compound. These results demonstrate the potential of (2E,6Z)-2,6-nonadienal to be used as a natural alternative to synthetic pesticides on F. verticillioides and S. zeamais.

  14. Effect of Selected Volatiles on Two Stored Pests: The Fungus Fusarium verticillioides and the Maize Weevil Sithophilus zeamais.

    PubMed

    Zunino, María P; Herrera, Jimena M; Pizzolitto, Romina P; Rubinstein, Héctor R; Zygadlo, Julio A; Dambolena, José S

    2015-09-01

    New agronomic practices and technology enabled Argentina a larger production of cereal grains, reaching a harvest yield of 26.5 million metric tons of maize, of which, about 40% was exported. However, much of the maize production is lost annually by the attack of fungi and insects (2.6 million tons). In this study, the antifungal effect of selected volatiles on Fusarium verticillioides, its mycotoxin production, and the repellent and insecticidal activities against the weevill Sithophilus zeamais, an insect vector of F. verticillioides, were evaluated. The compounds tested were (2E)-2-hexenal, (2E)-2-nonenal, (2E,6Z)-2,6-nonadienal, 1-pentanol, 1-hexanol, 1-butanol, 3-methyl-1-butanol, pentanal, 2-decanone, and 3-decanone, which occur in the blend of volatile compounds emitted by various cereal grains. The most active antifungals were the aldehydes (2E)-2-nonenal, (2E)-2-hexenal, and (2E,6Z)-2,6-nonadienal (minimum inhibitory concentration values of <0.03, 0.06, and 0.06 mM, respectively). The occurrence of fumonisin B1 also was prevented because these compounds completely inhibited fungal growth. The best insecticidal fumigant activities against the maize weevil were shown by 2-decanone and 3-decanone (lethal concentration ≤ 54.6 μL/L (<0.28 mM)). Although, all tested compounds showed repellent activity against S. zeamais at a concentration of 4 μL/L, (2E,6Z)-2,6-nonadienal was the most active repellent compound. These results demonstrate the potential of (2E,6Z)-2,6-nonadienal to be used as a natural alternative to synthetic pesticides on F. verticillioides and S. zeamais. PMID:26257042

  15. Effects of entomopathogenic fungus species, and impact of fertilizers, on biological control of pecan weevil (Coleoptera: Curculionidae).

    PubMed

    Shapiro-Ilan, David I; Gardner, Wayne A; Wells, Lenny; Cottrell, Ted E; Behle, Robert W; Wood, Bruce W

    2013-04-01

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan, Carya illinoinensis (Wangenh.) K. Koch. Prior research indicated the potential for use of Hypocreales fungi to suppress C. caryae. We compared the efficacy of two fungal spp., Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their ability to cause C. caryae mortality. The fungus, B. bassiana, was applied to trunks of pecan trees (a method previously shown to be effective in C. caryae suppression) and efficacy was compared with M. brunneum applied to the ground or to the trunk with or without SoyScreen Oil as an ultraviolet protecting agent. Results indicated B. bassiana to be superior to M. brunneum regardless of application method; consequently, the potential for applying B. bassiana to control C. caryae was explored further. Specifically, the impact of different fertilizer regimes (as used by pecan growers) on the persistence of B. bassiana (GHA) in soil was determined. B. bassiana was applied to soil in a pecan orchard after one of several fertilizer treatments--i.e., ammonium nitrate, crimson clover, poultry litter, clover plus poultry litter, and a no-fertilizer control. B. bassiana persistence up to 49 d in 2009 and 2010 was assessed by plating soil onto selective media and determining the number of colony forming units, and by baiting soil with a susceptible host, Galleria mellonella (L.). Fertilizer treatments did not impact B. bassiana persistence. We conclude that standard fertilizers for nitrogen management, when applied according to recommended practices, are unlikely to negatively impact survival of B. bassiana in pecan orchards when the fungus is applied for C. caryae suppression during weevil emergence. Additional research on interactions between entomopathogenic fungi and fertilizer amendments (or other tree nutrition or soil management practices) is merited. PMID:23575015

  16. Effects of entomopathogenic fungus species, and impact of fertilizers, on biological control of pecan weevil (Coleoptera: Curculionidae).

    PubMed

    Shapiro-Ilan, David I; Gardner, Wayne A; Wells, Lenny; Cottrell, Ted E; Behle, Robert W; Wood, Bruce W

    2013-04-01

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan, Carya illinoinensis (Wangenh.) K. Koch. Prior research indicated the potential for use of Hypocreales fungi to suppress C. caryae. We compared the efficacy of two fungal spp., Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their ability to cause C. caryae mortality. The fungus, B. bassiana, was applied to trunks of pecan trees (a method previously shown to be effective in C. caryae suppression) and efficacy was compared with M. brunneum applied to the ground or to the trunk with or without SoyScreen Oil as an ultraviolet protecting agent. Results indicated B. bassiana to be superior to M. brunneum regardless of application method; consequently, the potential for applying B. bassiana to control C. caryae was explored further. Specifically, the impact of different fertilizer regimes (as used by pecan growers) on the persistence of B. bassiana (GHA) in soil was determined. B. bassiana was applied to soil in a pecan orchard after one of several fertilizer treatments--i.e., ammonium nitrate, crimson clover, poultry litter, clover plus poultry litter, and a no-fertilizer control. B. bassiana persistence up to 49 d in 2009 and 2010 was assessed by plating soil onto selective media and determining the number of colony forming units, and by baiting soil with a susceptible host, Galleria mellonella (L.). Fertilizer treatments did not impact B. bassiana persistence. We conclude that standard fertilizers for nitrogen management, when applied according to recommended practices, are unlikely to negatively impact survival of B. bassiana in pecan orchards when the fungus is applied for C. caryae suppression during weevil emergence. Additional research on interactions between entomopathogenic fungi and fertilizer amendments (or other tree nutrition or soil management practices) is merited.

  17. Morphology of the male reproductive system, sperm ultrastructure and γ-irradiation of the red palm weevil Rhynchophorus ferrugineus Oliv. (Coleoptera: Dryophthoridae).

    PubMed

    Paoli, Francesco; Dallai, Romano; Cristofaro, Massimo; Arnone, Silvia; Francardi, Valeria; Roversi, Pio Federico

    2014-08-01

    In the present study we describe the morphology of the male reproductive apparatus and sperm ultrastructure of the red palm weevil - an invasive pest of several palm tree species - as well as the most important steps of spermatogenesis. The reproductive apparatus consists of a pair of testes (each formed by two lobes) a long tube-like accessory gland, a prostate gland and a small accessory gland. Characteristic features of the sperm are 90-100 μm total length, 10 μm nucleus, two mitochondrial derivatives, two accessory bodies, one well-developed puff-like structure and a typical insect 9+9+2 flagellar axoneme. One of the methods used for the biological control of pests is the Sterile Insect Technique (SIT), for the evaluation of which we make a preliminary comparison of the sperm ultrastructure of non-irradiated and irradiated weevils (at a dose of 80 Gray).

  18. The adventive status of Salvinia minima and S. molestain the southern United States and the related distribution of the weevil Cyrtobagous salviniae

    USGS Publications Warehouse

    Jacono, Colette C.; Davern, Tracy R.; Center, Ted D.

    2001-01-01

    The recent introduction of Salvinia molesta constitutes a serious threat to aquatic systems in the warm temperate regions of the United States. Salvinia minima, the only other member of Salviniaceae present in North America, is considered native by current floras. Evidence is presented which suggests that Salvinia minima was also introduced to North America, probably during the late 1920s and early 1930s. Likely sites of introduction and subsequent range expansions are identified. The accidentally introduced salvinia weevil, putatively Cyrtobagous salviniae, was found to occur widely on S. minima in Florida but is not established in other states. The disparate distribution of this Salvinia herbivore may account for the reduced aggressiveness of S. minima in Florida as compared to its troublesome growth in Texas and LOUisiana, where the weevil is not yet known.

  19. (1R,2S,6R)-Papayanal: a new male-specific volatile compound released by the guava weevil Conotrachelus psidii (Coleoptera: Curculionidae).

    PubMed

    Romero-Frías, Alicia; Murata, Yasuhiro; Simões Bento, José Maurício; Osorio, Coralia

    2016-05-01

    The guava weevil, Conotrachelus psidii is an aggressive pest of guava (Psidium guajava L.) that causes irreparable damages inside the fruit. The volatile compounds of male and female insects were separately collected by headspace solid-phase microextraction or with dynamic headspace collection on a polymer sorbent, and comparatively analyzed by GC-MS. (1R,2S,6R)-2-Hydroxymethyl-2,6-dimethyl-3-oxabicyclo[4.2.0]octane (papayanol), and (1R,2S,6R)-2,6-dimethyl-3-oxabicyclo[4.2.0]octane-2-carbaldehyde (papayanal) were identified (ratio of 9:1, respectively) as male-specific guava weevil volatiles. Papayanal structure was confirmed by comparison of spectroscopic (EIMS) and chromatographic (retention time) data with those of the synthetic pure compound. The behavioral response of the above-mentioned compounds was studied in a Y-tube olfactometer bioassay, and their role as aggregation pheromone candidate components was suggested in this species.

  20. Response of Pisum sativum (Fabales: Fabaceae) to Sitona lineatus (Coleoptera: Curculionidae) infestation: effect of adult weevil density on damage, larval population, and yield loss.

    PubMed

    Vankosky, M A; Cárcamo, H A; Dosdall, L M

    2011-10-01

    Sitona lineatus L. (Coleoptera: Curculionidae) is an invasive pest in North America and its geographical range is currently expanding across the Canadian prairies. Adults and larvae of S. lineatus feed upon the foliage and root nodules, respectively, of field pea, Pisum sativum L. (Fabales: Fabaceae), and may contribute to economic losses when population densities are high. Integrated pest management (IPM) programs that incorporate economic thresholds should be used to manage S. lineatus populations in a sustainable manner. The impact of nitrogen fertilizer on field pea yield and the relationships between adult weevil density and above- and below-ground damage and yield were investigated in southern Alberta, Canada using exclusion cages on field pea plots. In each cage, 32 field pea plants were exposed to weevil densities ranging from zero to one adult weevil per plant. Nitrogen-fertilized plants yielded 16% more than unfertilized plants. Nitrogen-fertilized plants had fewer root nodules than unfertilized plants, but fertilizer had no effect on foliar feeding by S. lineatus. Adult density affected foliar feeding damage, with increases in above-ground damage associated with increases in S. lineatus density. Adult density did not affect root nodule damage, larval density, foliar biomass or seed weight. Overall, these results indicate that terminal leaf damage may be used to estimate adult weevil density but cannot be used to predict larval density or yield loss. Further research is required to better understand the impact of larval damage on yield and determine if economic thresholds can be developed using data from large-scale production systems.

  1. A new light on the evolution and propagation of prehistoric grain pests: the world's oldest maize weevils found in Jomon Potteries, Japan.

    PubMed

    Obata, Hiroki; Manabe, Aya; Nakamura, Naoko; Onishi, Tomokazu; Senba, Yasuko

    2011-01-01

    Three Sitophilus species (S. granarius L., S. oryzae L., and S. zeamais Mots.) are closely related based on DNA analysis of their endosymbionts. All are seed parasites of cereal crops and important economic pest species in stored grain. The Sitophilus species that currently exist, including these three species, are generally believed to be endemic to Asia's forested areas, suggesting that the first infestations of stored grain must have taken place near the forested mountains of southwestern Asia. Previous archaeological data and historical records suggest that the three species may have been diffused by the spread of Neolithic agriculture, but this hypothesis has only been established for granary weevils in European and southwestern Asian archaeological records. There was little archeological evidence for grain pests in East Asia before the discovery of maize weevil impressions in Jomon pottery in 2004 using the "impression replica" method. Our research on Jomon agriculture based on seed and insect impressions in pottery continued to seek additional evidence. In 2010, we discovered older weevil impressions in Jomon pottery dating to ca. 10 500 BP. These specimens are the oldest harmful insects in the world discovered at archaeological sites. Our results provide evidence of harmful insects living in the villages from the Earliest Jomon, when no cereals were cultivated. This suggests we must reconsider previous scenarios for the evolution and propagation of grain pest weevils, especially in eastern Asia. Although details of their biology or the foods they infested remain unclear, we hope future interdisciplinary collaborations among geneticists, entomologists, and archaeologists will provide the missing details.

  2. Silencing the Olfactory Co-Receptor RferOrco Reduces the Response to Pheromones in the Red Palm Weevil, Rhynchophorus ferrugineus.

    PubMed

    Soffan, Alan; Antony, Binu; Abdelazim, Mahmoud; Shukla, Paraj; Witjaksono, Witjaksono; Aldosari, Saleh A; Aldawood, Abdulrahman S

    2016-01-01

    The red palm weevil (RPW, Rhynchophorus ferrugineus), one of the most widespread of all invasive insect pest species, is a major cause of severe damage to economically important palm trees. RPW exhibits behaviors very similar to those of its sympatric species, the Asian palm weevil (R. vulneratus), which is restricted geographically to the southern part of Southeast Asia. Although efficient and sustainable control of these pests remains challenging, olfactory-system disruption has been proposed as a promising approach for controlling palm weevils. Here, we report the cloning and sequencing of an olfactory co-receptor (Orco) from R. ferrugineus (RferOrco) and R. vulneratus (RvulOrco) and examine the effects of RferOrco silencing (RNAi) on odorant detection. RferOrco and RvulOrco encoding 482 amino acids showing 99.58% identity. The injection of double-stranded RNA (dsRNA) from RferOrco into R. ferrugineus pupae significantly reduced RferOrco gene expression and led to the failure of odor-stimulus detection, as confirmed through olfactometer and electroantennography (EAG) assays. These results suggest that olfactory-system disruption leading to reduced pheromone detection holds great potential for RPW pest-control strategies. PMID:27606688

  3. Infectivity of Steinernema carpocapsae and S. feltiae to Larvae and Adults of the Hazelnut Weevil, Curculio nucum: Differential Virulence and Entry Routes

    PubMed Central

    Batalla-Carrera, Laia; Morton, Ana; Shapiro-Ilan, David; Strand, Michael R.; García-del-Pino, Fernando

    2014-01-01

    We investigated the existing susceptibility differences of the hazelnut weevil, Curculio nucum L. (Coleoptera:, Curculionidae) to entomopathogenic nematodes by assessing the main route of entry of the nematodes, Steinernema carpocapsae strain B14 and S. feltiae strain D114, into larvae and adult insects, as well as host immune response. Our results suggested that S. carpocapsae B14 and S. feltiae D114 primarily entered adult insects and larvae through the anus. Larvae were more susceptible to S. feltiae D114 than S. carpocapsae B14 and adults were highly susceptible to S. carpocapsae B14 but displayed low susceptibility to S. feltiae D114. Penetration rate correlated with nematode virulence. We observed little evidence that hazelnut weevils mounted any cellular immune response toward S. carpocapsae B14 or S. feltiae D114. We conclude the differential susceptibility of hazelnut weevil larvae and adults to S. carpocapsae B14 and S. feltiae D114 primarily reflected differences in the ability of these two nematodes to penetrate the host. PMID:25276002

  4. Infectivity of Steinernema carpocapsae and S. feltiae to Larvae and Adults of the Hazelnut Weevil, Curculio nucum: Differential Virulence and Entry Routes.

    PubMed

    Batalla-Carrera, Laia; Morton, Ana; Shapiro-Ilan, David; Strand, Michael R; García-Del-Pino, Fernando

    2014-09-01

    We investigated the existing susceptibility differences of the hazelnut weevil, Curculio nucum L. (Coleoptera:, Curculionidae) to entomopathogenic nematodes by assessing the main route of entry of the nematodes, Steinernema carpocapsae strain B14 and S. feltiae strain D114, into larvae and adult insects, as well as host immune response. Our results suggested that S. carpocapsae B14 and S. feltiae D114 primarily entered adult insects and larvae through the anus. Larvae were more susceptible to S. feltiae D114 than S. carpocapsae B14 and adults were highly susceptible to S. carpocapsae B14 but displayed low susceptibility to S. feltiae D114. Penetration rate correlated with nematode virulence. We observed little evidence that hazelnut weevils mounted any cellular immune response toward S. carpocapsae B14 or S. feltiae D114. We conclude the differential susceptibility of hazelnut weevil larvae and adults to S. carpocapsae B14 and S. feltiae D114 primarily reflected differences in the ability of these two nematodes to penetrate the host.

  5. Silencing the Olfactory Co-Receptor RferOrco Reduces the Response to Pheromones in the Red Palm Weevil, Rhynchophorus ferrugineus

    PubMed Central

    Soffan, Alan; Abdelazim, Mahmoud; Shukla, Paraj; Witjaksono, Witjaksono; Aldosari, Saleh A.; Aldawood, Abdulrahman S.

    2016-01-01

    The red palm weevil (RPW, Rhynchophorus ferrugineus), one of the most widespread of all invasive insect pest species, is a major cause of severe damage to economically important palm trees. RPW exhibits behaviors very similar to those of its sympatric species, the Asian palm weevil (R. vulneratus), which is restricted geographically to the southern part of Southeast Asia. Although efficient and sustainable control of these pests remains challenging, olfactory-system disruption has been proposed as a promising approach for controlling palm weevils. Here, we report the cloning and sequencing of an olfactory co-receptor (Orco) from R. ferrugineus (RferOrco) and R. vulneratus (RvulOrco) and examine the effects of RferOrco silencing (RNAi) on odorant detection. RferOrco and RvulOrco encoding 482 amino acids showing 99.58% identity. The injection of double-stranded RNA (dsRNA) from RferOrco into R. ferrugineus pupae significantly reduced RferOrco gene expression and led to the failure of odor-stimulus detection, as confirmed through olfactometer and electroantennography (EAG) assays. These results suggest that olfactory-system disruption leading to reduced pheromone detection holds great potential for RPW pest-control strategies. PMID:27606688

  6. The Complexity of Posttranscriptional Small RNA Regulatory Networks Revealed by In Silico Analysis of Gossypium arboreum L. Leaf, Flower and Boll Small Regulatory RNAs

    PubMed Central

    Hu, Hongtao; Rashotte, Aaron M.; Singh, Narendra K.; Weaver, David B.; Goertzen, Leslie R.; Singh, Shree R.; Locy, Robert D.

    2015-01-01

    MicroRNAs (miRNAs) and secondary small interfering RNAs (principally phased siRNAs or trans-acting siRNAs) are two distinct subfamilies of small RNAs (sRNAs) that are emerging as key regulators of posttranscriptional gene expression in plants. Both miRNAs and secondary-siRNAs (sec-siRNAs) are processed from longer RNA precursors by DICER-LIKE proteins (DCLs). Gossypium arboreum L., also known as tree cotton or Asian cotton, is a diploid, possibly ancestral relative of tetraploid Gossypium hirsutum L., the predominant type of commercially grown cotton worldwide known as upland cotton. To understand the biological significance of these gene regulators in G. arboreum, a bioinformatics analysis was performed on G. arboreum small RNAs produced from G. arboreum leaf, flower, and boll tissues. Consequently, 263 miRNAs derived from 353 precursors, including 155 conserved miRNAs (cs-miRNAs) and 108 novel lineage-specific miRNAs (ls-miRNAs). Along with miRNAs, 2,033 miRNA variants (isomiRNAs) were identified as well. Those isomiRNAs with variation at the 3’-miRNA end were expressed at the highest levels, compared to other types of variants. In addition, 755 pha-siRNAs derived 319 pha-siRNA gene transcripts (PGTs) were identified, and the potential pha-siRNA initiators were predicted. Also, 2,251 non-phased siRNAs were found as well, of which 1,088 appeared to be produced by so-called cis- or trans-cleavage of the PGTs observed at positions differing from pha-siRNAs. Of those sRNAs, 148 miRNAs/isomiRNAs and 274 phased/non-phased siRNAs were differentially expressed in one or more pairs of tissues examined. Target analysis revealed that target genes for both miRNAs and pha-siRNAs are involved a broad range of metabolic and enzymatic activities. We demonstrate that secondary siRNA production could result from initial cleavage of precursors by both miRNAs or isomiRNAs, and that subsequently produced phased and unphased siRNAs could result that also serve as triggers of a

  7. Radiation induced changes in the cuticular hydrocarbons of the granary weevil and their relationships to desiccation and adult mortality: Annual progress report, February 15, 1987 to February 14, 1988

    SciTech Connect

    Sriharan, S.

    1988-03-14

    Sitophilus granarius (L) is a major pest of stroed grains and is prone to irradiation treatment. There is considerable scope for use of radiation like Cesium-137 (as a source) as an alternative to chemical treatment for pest control. Study with regard to radiation damage and the effect of environmental factors like temperature and humidity on adult weevil mortality due to radiation effect is limited. Stored-grain insects live in an enviroment where liquid water is seldom available. Waterproofing and conservation of water by the insects is a critical factor for weevil survival. In some insects it has been noted that the rate of water loss through the integument has been associated with changes in the hydrocarbon composition of the epicuticle. Epicuticular hydrocarbons play an important role in preventing desiccation. Information on the effects of irradiation on epicuticular hydrocarbon of the adult weevils is limited. The present investigation sudies the after effects of radiation damage to granary weevil (Sitophilus granarius (L.) in terms of causing increased water loss from the body, weevil nortality and concommitant changes, if any, in the cuticular hydrocarbons that waterproof the insect. 23 refs., 22 figs., 7 tabs.

  8. Multidisciplinary Fingerprints: Forensic Reconstruction of an Insect Reinvasion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beginning late August 2007, more than 150 boll weevils, Anthonomus grandis, were unexpectedly captured across an extensive area of the Southern Rolling Plains (SRP) eradication zone of West-Central Texas, which was essentially weevil-free since 2003. This outbreak was detected soon after the passag...

  9. Screening of tropical isolates of Metarhizium anisopliae for virulence to the red palm weevil Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae).

    PubMed

    Sun, Xiaodong; Yan, Wei; Qin, Weiquan; Zhang, Jing; Niu, Xiaoqing; Ma, Guangchang; Li, Fuheng

    2016-01-01

    The red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) is a serious pest of the palm tree in tropical regions of the world. One strain of Metarhizium sp. ZJ-1, isolated from Chinese soils, was evaluated for growth characteristics, and screened for its virulence to R. ferrugineus larvae in laboratory conditions. An approximately 685-bp fragment was amplified by ITS (ITS1-5.8S-ITS2) PCR from strain ZJ-1, further phylogenetic analysis revealed that 93 % similarity to Metarhizium anisopliae. Inoculation of 1 × 10(8) conidia/mL caused 100 % mortality of R. ferrugineus, LT50 levels of ZJ-1 were 1.66 days (1 × 10(8) conidia/mL), indicating that the conidia of strain ZJ-1 were highly virulent. These results suggest that M. anisopliae ZJ-1 has potential as an effective and persistent biological control agent for R. ferrugineus. PMID:27468401

  10. Fumigant Toxicity of Lamiaceae Plant Essential Oils and Blends of Their Constituents against Adult Rice Weevil Sitophilus oryzae.

    PubMed

    Kim, Sung-Woong; Lee, Hyo-Rim; Jang, Myeong-Jin; Jung, Chan-Sik; Park, Il-Kwon

    2016-01-01

    To find a new and safe alternative to conventional insecticides, we evaluated the fumigant toxicity of eight Lamiaceae essential oils and their constituents against the adult rice weevil Sitophilus oryzae. Of the eight species tested, hyssop (Hyssopus offcinalis), majoram (Origanum majorana), and Thymus zygis essential oils showed strong fumigant toxicity against S. oryzae adults at 25 mg/L air concentration. Constituents of active essential oils were analyzed by gas chromatography coupled to flame ionization detector (FID) and gas chromatography-mass spectrometry. A total of 13, 15, and 17 compounds were identified from hyssop, majoram, and Thymus zygis essential oils, respectively. Pinocamphone and isopinocamphone were isolated by open column chromatography. Among the test compounds, pinocamphone and isopinocamphone showed the strongest fumigant toxicity against S. oryzae. Sabinene hydrate, linalool, α-terpineol, and terpinen-4-ol exhibited 100% fumigant toxicity against S. oryzae at 3.9 mg/L air concentration. The measured toxicity of the artificial blends of the constituents identified in hyssop, majoram, and Thymus zygis oils indicated that isopinocamphone, terpine-4-ol, and linalool were major contributors to the fumigant toxicity of the artificial blend, respectively. PMID:26999084

  11. Impact of Water Management on Efficacy of Insecticide Seed Treatments Against Rice Water Weevil (Coleoptera: Curculionidae) in Mississippi Rice

    PubMed Central

    Adams, A.; Gore, J.; Musser, F.; Cook, D.; Catchot, A.; Walker, T.; Awuni, G. A.

    2015-01-01

    Two experiments were conducted at the Delta Research and Extension Center in Stoneville, MS, during 2011 and 2012 to determine the impact of water management practices on the efficacy of insecticidal seed treatments targeting rice water weevil, Lissorhoptrus oryzophilus Kuschel. Larval densities and yield were compared for plots treated with labeled rates of thiamethoxam, chlorantraniliprole, and clothianidin and an untreated control. In the first experiment, plots were subjected to flood initiated at 6 and 8 wk after planting. Seed treatments significantly reduced larval densities with the 8-wk flood timing, but not the 6-wk flood timing. Overall, the treated plots yielded higher than the control plots. In the second experiment, the impact of multiple flushes on the efficacy of insecticidal seed treatments was evaluated. Plots were subjected to zero, one, or two flushes with water. All seed treatments reduced larval densities compared with the untreated control. Significantly fewer larvae were observed in plots that received one or two flushes compared with plots that did not receive a flush. All seed treatments resulted in higher yields compared to the untreated control in the zero and one flush treatments. When two flushes were applied, yield from the thiamethoxam and clothianidin treated plots was not significantly different from those of the control plots, while the chlorantraniliprole treated plots yielded significantly higher than the control. These data suggest that time from planting to flood did not impact the efficacy of seed treatments, but multiple flushes reduced the efficacy of thiamethoxam and clothianidin. PMID:26470232

  12. Impact of Water Management on Efficacy of Insecticide Seed Treatments Against Rice Water Weevil (Coleoptera: Curculionidae) in Mississippi Rice.

    PubMed

    Adams, A; Gore, J; Musser, F; Cook, D; Catchot, A; Walker, T; Awuni, G A

    2015-06-01

    Two experiments were conducted at the Delta Research and Extension Center in Stoneville, MS, during 2011 and 2012 to determine the impact of water management practices on the efficacy of insecticidal seed treatments targeting rice water weevil, Lissorhoptrus oryzophilus Kuschel. Larval densities and yield were compared for plots treated with labeled rates of thiamethoxam, chlorantraniliprole, and clothianidin and an untreated control. In the first experiment, plots were subjected to flood initiated at 6 and 8 wk after planting. Seed treatments significantly reduced larval densities with the 8-wk flood timing, but not the 6-wk flood timing. Overall, the treated plots yielded higher than the control plots. In the second experiment, the impact of multiple flushes on the efficacy of insecticidal seed treatments was evaluated. Plots were subjected to zero, one, or two flushes with water. All seed treatments reduced larval densities compared with the untreated control. Significantly fewer larvae were observed in plots that received one or two flushes compared with plots that did not receive a flush. All seed treatments resulted in higher yields compared to the untreated control in the zero and one flush treatments. When two flushes were applied, yield from the thiamethoxam and clothianidin treated plots was not significantly different from those of the control plots, while the chlorantraniliprole treated plots yielded significantly higher than the control. These data suggest that time from planting to flood did not impact the efficacy of seed treatments, but multiple flushes reduced the efficacy of thiamethoxam and clothianidin. PMID:26470232

  13. Pyrosequencing the Midgut Transcriptome of the Banana Weevil Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) Reveals Multiple Protease-Like Transcripts.

    PubMed

    Valencia, Arnubio; Wang, Haichuan; Soto, Alberto; Aristizabal, Manuel; Arboleda, Jorge W; Eyun, Seong-Il; Noriega, Daniel D; Siegfried, Blair

    2016-01-01

    The banana weevil Cosmopolites sordidus is an important and serious insect pest in most banana and plantain-growing areas of the world. In spite of the economic importance of this insect pest very little genomic and transcriptomic information exists for this species. In the present study, we characterized the midgut transcriptome of C. sordidus using massive 454-pyrosequencing. We generated over 590,000 sequencing reads that assembled into 30,840 contigs with more than 400 bp, representing a significant expansion of existing sequences available for this insect pest. Among them, 16,427 contigs contained one or more GO terms. In addition, 15,263 contigs were assigned an EC number. In-depth transcriptome analysis identified genes potentially involved in insecticide resistance, peritrophic membrane biosynthesis, immunity-related function and defense against pathogens, and Bacillus thuringiensis toxins binding proteins as well as multiple enzymes involved with protein digestion. This transcriptome will provide a valuable resource for understanding larval physiology and for identifying novel target sites and management approaches for this important insect pest. PMID:26949943

  14. Pyrosequencing the Midgut Transcriptome of the Banana Weevil Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) Reveals Multiple Protease-Like Transcripts.

    PubMed

    Valencia, Arnubio; Wang, Haichuan; Soto, Alberto; Aristizabal, Manuel; Arboleda, Jorge W; Eyun, Seong-Il; Noriega, Daniel D; Siegfried, Blair

    2016-01-01

    The banana weevil Cosmopolites sordidus is an important and serious insect pest in most banana and plantain-growing areas of the world. In spite of the economic importance of this insect pest very little genomic and transcriptomic information exists for this species. In the present study, we characterized the midgut transcriptome of C. sordidus using massive 454-pyrosequencing. We generated over 590,000 sequencing reads that assembled into 30,840 contigs with more than 400 bp, representing a significant expansion of existing sequences available for this insect pest. Among them, 16,427 contigs contained one or more GO terms. In addition, 15,263 contigs were assigned an EC number. In-depth transcriptome analysis identified genes potentially involved in insecticide resistance, peritrophic membrane biosynthesis, immunity-related function and defense against pathogens, and Bacillus thuringiensis toxins binding proteins as well as multiple enzymes involved with protein digestion. This transcriptome will provide a valuable resource for understanding larval physiology and for identifying novel target sites and management approaches for this important insect pest.

  15. Application of Laser Induced Breakdown Spectroscopy in Early Detection of Red Palm Weevil: (Rhynchophorus ferrugineus) Infestation in Date Palm

    NASA Astrophysics Data System (ADS)

    A. Farooq, W.; G. Rasool, K.; Walid, Tawfik; S. Aldawood, A.

    2015-11-01

    The Kingdom of Saudi Arabia is one of the leading date producing countries. Unfortunately, this important fruit crop is under great threat from the red palm weevil (RPW) (Rhynchophorus ferrugineus), which is a highly invasive pest. Several techniques, including visual inspection, acoustic sensors, sniffer dogs, and pheromone traps have been tried to detect the early stages of a RPW infestation; however, each method has suffered certain logistical and implementation issues. We have applied laser induced breakdown spectroscopy (LIBS) for the early detection of RPW infestation. Through the analysis of the observed LIBS spectra of different infested and healthy samples, we have found presence of Ca, Mg, Na, C, K elements and OH, CN molecules. The spectra also reveal that with the population growth of the pest, the intensity of Mg and Ca atomic lines in LIBS spectra increases rapidly. Similar behavior is observed in the molecular lines of LIBS spectra. The obtained results indicate that the LIBS technique can be used for the early detection of RPW infestation without damaging the date palms.

  16. Laboratory evaluation of chemical-biological control of the rice weevil (Sitophilus oryzae L.) in stored grains.

    PubMed

    Dal Bello G; Padin; López Lastra C; Fabrizio

    2000-01-15

    The virulence of ten different fungal isolates of: Beauveria bassiana, Metarhizium anisopliae, Verticillium lecanii and Paecilomyces farinosus to the rice weevil Sitophilus oryzae was tested. A fungal mix of the most efficient isolates, B. bassiana ARSEF 5500+M. anisopliae ARSEF 2974, which caused the highest mortality, was assayed in combination with fenitrothion at a concentration lower (3 ppm) than the normal 6 ppm. Fungal inoculation of insects was done by spraying conidial suspensions of each fungus on wheat. Insecticide formulations were added by spraying wheat. Treated and untreated insects were incubated on durum wheat. Insects were kept in a climatized chamber for 30 days. Observations were performed at 7, 14 and 30 days to record insect mortality. Highly significant differences were demonstrated for B. bassiana 5500 and 5501 and for M. anisopliae 2974. The level of mortality produced by treatments was: 6 ppm insecticide=97.50%, B. bassiana ARSEF 5500+M. anisopliae ARSEF 2974+3 ppm insecticide=74.17%, B. bassiana ARSEF 5500+M.anisopliae ARSEF 2974=50% and 3 ppm insecticide=37.50%. There was a statistically significant difference (p<0.05) among treatments.

  17. Expression of Heat Shock Protein Genes in Different Developmental Stages and After Temperature Stress in the Maize Weevil (Coleoptera: Curculionidae).

    PubMed

    Tungjitwitayakul, Jatuporn; Tatun, Nujira; Vajarasathira, Boongeua; Sakurai, Sho

    2015-06-01

    The maize weevil, Sitophilus zeamais Motschulsky, is a major pest of rice and other postharvest grain stocks in tropical countries. Heating and cooling treatments have been adopted to control this pest. Because heat shock protein (hsp) genes respond to temperature stress, we examined the association of hsp genes with development and thermal stress in S. zeamais. The temperature response of the insect to heat and cold treatments was assessed at four developmental stages: egg, larva, pupa, and adult. LT50 values at high temperatures were similar among the four developmental stages, while adults were the most tolerant to low temperatures, and eggs, larvae, and pupae exhibited similar LT50 values. Expression levels of three hsps--Szhsp70, Szhsc70, and Szhsp90--fluctuated substantially throughout the four stages at a rearing temperature of 28°C. Heat shock and cold shock increased the expression of all three hsps, and the highest upregulation was observed at 40°C, although the intensity of upregulation varied among the three genes: strongly in Szhsp70, moderately in Szhsp90, and slightly in Szhsc70. Basal expression of the three hsps at 28°C and gene responses to heat and cold shock also varied significantly at the tissue level.

  18. Demographic comparison of sweetpotato weevil reared on a major host, Ipomoea batatas, and an alternative host, I. triloba

    PubMed Central

    Reddy, Gadi V. P.; Chi, Hisn

    2015-01-01

    In this study, we collected life table data for the sweetpotato weevil, Cylas formicarius, grown on Ipomoea batatas and Ipomoea triloba, and analyzed them using an age-stage, two-sex life table. We also demonstrated the growth potential of C. formicarius on these two host plants by using population projection. These data will be useful to the growers to the selection or eradication of host plants in an integrated control strategy for C. formicarius for the entire area of the targeted areas. We found that C. formicarius developed faster on I. batatas than on I. triloba. The developmental times of the larval and pupal stages on I. batatas than on I. triloba were 37.01 and 8.3 days. The adult females emerged before and began to produce eggs at 42 days earlier when reared on I. batatas. The fecundity of females was 90.0 eggs on I. batatas significantly higher than the mean fecundity of 68.5 eggs on I. triloba. Although this insect has a higher intrinsic rate of increase on I. batatas, the study indicated that C. formicarius can successfully survive and reproduce on both host plants. PMID:26156566

  19. Pyrosequencing the Midgut Transcriptome of the Banana Weevil Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) Reveals Multiple Protease-Like Transcripts

    PubMed Central

    Valencia, Arnubio; Wang, Haichuan; Soto, Alberto; Aristizabal, Manuel; Arboleda, Jorge W.; Eyun, Seong-il; Noriega, Daniel D.; Siegfried, Blair

    2016-01-01

    The banana weevil Cosmopolites sordidus is an important and serious insect pest in most banana and plantain-growing areas of the world. In spite of the economic importance of this insect pest very little genomic and transcriptomic information exists for this species. In the present study, we characterized the midgut transcriptome of C. sordidus using massive 454-pyrosequencing. We generated over 590,000 sequencing reads that assembled into 30,840 contigs with more than 400 bp, representing a significant expansion of existing sequences available for this insect pest. Among them, 16,427 contigs contained one or more GO terms. In addition, 15,263 contigs were assigned an EC number. In-depth transcriptome analysis identified genes potentially involved in insecticide resistance, peritrophic membrane biosynthesis, immunity-related function and defense against pathogens, and Bacillus thuringiensis toxins binding proteins as well as multiple enzymes involved with protein digestion. This transcriptome will provide a valuable resource for understanding larval physiology and for identifying novel target sites and management approaches for this important insect pest. PMID:26949943

  20. MOSCAB (Materia OSCura A Bolle)

    NASA Astrophysics Data System (ADS)

    Pullia, Antonino

    2016-05-01

    This kind of detector (Geyser) has never been realized for the Elementary Particle Physics (it was constructed once in BERN A in 1964 by Hahn and Reist to detect transuranic nuclei. The Geyser is substantially a Vessel consisting of a “FLASK” containing a superheated liquid (f.i. some kind of freon) and a “NECK” (containing partially a separation liquid and partially the freon vapor). The Geyser was realized in Milano by setting the two different parts of the detector (flask and neck, filled in our case by freon C3 F8 , at different temperatures. The part of the overheated liquid was kept at higher temperature (f.i. 25 degree) and the gaseous part was kept at lower temperature (f.i. 18 degrees).

  1. Colonization of Artificially Stressed Black Walnut Trees by Ambrosia Beetle, Bark Beetle, and Other Weevil Species (Coleoptera: Curculionidae) in Indiana and Missouri.

    PubMed

    Reed, Sharon E; Juzwik, Jennifer; English, James T; Ginzel, Matthew D

    2015-12-01

    Thousand cankers disease (TCD) is a new disease of black walnut (Juglans nigra L.) in the eastern United States. The disease is caused by the interaction of the aggressive bark beetle Pityophthorus juglandis Blackman and the canker-forming fungus, Geosmithia morbida M. Kolarik, E. Freeland, C. Utley & Tisserat, carried by the beetle. Other insects also colonize TCD-symptomatic trees and may also carry pathogens. A trap tree survey was conducted in Indiana and Missouri to characterize the assemblage of ambrosia beetles, bark beetles, and other weevils attracted to the main stems and crowns of stressed black walnut. More than 100 trees were girdled and treated with glyphosate (Riverdale Razor Pro, Burr Ridge, Illinois) at 27 locations. Nearly 17,000 insects were collected from logs harvested from girdled walnut trees. These insects represented 15 ambrosia beetle, four bark beetle, and seven other weevil species. The most abundant species included Xyleborinus saxeseni Ratzburg, Xylosandrus crassiusculus Motschulsky, Xylosandrus germanus Blandford, Xyleborus affinis Eichhoff, and Stenomimus pallidus Boheman. These species differed in their association with the stems or crowns of stressed trees. Multiple species of insects were collected from individual trees and likely colonized tissues near each other. At least three of the abundant species found (S. pallidus, X. crassiusculus, and X. germanus) are known to carry propagules of canker-causing fungi of black walnut. In summary, a large number of ambrosia beetles, bark beetles, and other weevils are attracted to stressed walnut trees in Indiana and Missouri. Several of these species have the potential to introduce walnut canker pathogens during colonization.

  2. Relative concentration of Cry1A in maize leaves and cotton bolls with diverse chlorophyll content and corresponding larval development of fall armyworm (Lepidoptera: Noctuidae) and southwestern corn borer (Lepidoptera: Crambidae) on maize whorl leaf profiles.

    PubMed

    Abel, Craig A; Adamczyk, John J

    2004-10-01

    of the southwestern corn borer to the toxin. In cotton, Gossypium hirsutum L., the amount of Cry1Ac was significantly lower in boll tips where flowers had remained attached compared with normal boll tips. Boll tips where the flowers remained attached are often the site where corn earworms, Helicoverpa zea (Boddie), penetrate Bt cotton bolls. This study demonstrated that, in two diverse plant species, tissue that has low chlorophyll content does not fully express Cry1A. Photosynthesis regulating factors related to mRNA transcription and translation should be studied for their effect on Cry1A production and insect control.

  3. The Lesser of Two Weevils: Molecular-Genetics of Pest Palm Weevil Populations Confirm Rhynchophorus vulneratus (Panzer 1798) as a Valid Species Distinct from R. ferrugineus (Olivier 1790), and Reveal the Global Extent of Both

    PubMed Central

    Rugman-Jones, Paul F.; Hoddle, Christina D.; Hoddle, Mark S.; Stouthamer, Richard

    2013-01-01

    The red palm weevil (RPW) is a major pest of palms. It is native to southeast Asia and Melanesia, but in recent decades has vastly expanded its range as the result of multiple accidental anthropogenic introductions into the Middle East, Mediterranean Basin, Caribbean, and U.S.A. Currently regarded as a single species, Rhynchophorus ferrugineus (Olivier), RPW displays remarkable color variation across its range, and consequently has a taxonomic history littered with new species descriptions and synonymization. We compared DNA sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene from RPW populations throughout the native and invaded ranges, to investigate the specific status and invasion history of this serious economic pest, and to identify possible common routes of entry. Analyses of COI haplotype data provide conclusive support, corroborated by sequences of additional nuclear gene regions, for the existence of at least two predominantly allopatric species. The true R. ferrugineus is native only to the northern and western parts of continental southeast Asia, Sri Lanka and the Philippines, and is responsible for almost all invasive populations worldwide. In contrast, the second species, which is currently synonymized under R. ferrugineus and should be resurrected under the name R. vulneratus (Panzer), has a more southern distribution across Indonesia, and is responsible for only one invasive population; that in California, U.S.A. The distribution of COI haplotypes is used to discuss the possible existence of further cryptic species, sources and routes of entry of different invasive populations, and the implications of our findings for current control methods. PMID:24143263

  4. Azadirachtin-induced hormesis mediating shift in fecundity-longevity trade-off in the Mexican bean weevil (Chrysomelidae: Bruchinae).

    PubMed

    Mallqui, K S Vilca; Vieira, J L; Guedes, R N C; Gontijo, L M

    2014-04-01

    Insecticides can have lethal or sublethal effects upon targeted pest species, and sublethal effects may even favor pest outbreaks if insecticide-induced hormesis occurs. Hormesis is a biphasic dose-response of a given chemical compound that is stimulatory at low doses and toxic at high doses. The former response may result from the disruption of animal homeostasis leading to trade-off shifts between basic ecophysiological processes. A growing interest in the use of biorational insecticides, such as azadirachtin to control stored-product pests, raises concerns about potential sublethal effects. In this study, we explored the hypothesis that azadirachtin can negatively impact the reproductive capacity of the Mexican bean weevil, Zabrotes subfasciatus (Boheman) (Chrysomelidae: Bruchinae), a key pest of stored beans. In addition, we investigated whether adults of this species could compensate for any sublethal effect that might have affected any of their reproductive parameters by adjusting the allocation of its reproductive efforts. The results showed that females of Z. subfasciatus increased fecundity daily to compensate for azadirachtin-induced decreased longevity. In addition, a stage-structured matrix study revealed that populations of Z. subfasciatus engendered from females exposed to azadirachtin exhibited a higher rate of population increase (r) and a higher net reproductive rate (R(o)). Finally, a projection matrix analysis showed notably higher densities along the generations for azadirachtin-exposed Z. subfasciatus populations. Thus, our study provides empirical evidence for the capacity of Z. subfasciatus to adapt to sublethal effects caused by biorational insecticides; consequently, this study highlights the importance of understanding this phenomenon when devising pest management strategies. PMID:24772571

  5. Locomotory and physiological responses induced by clove and cinnamon essential oils in the maize weevil Sitophilus zeamais.

    PubMed

    Gonzales Correa, Yenis Del Carmen; Faroni, Lêda R A; Haddi, Khalid; Oliveira, Eugênio E; Pereira, Eliseu José G

    2015-11-01

    Plant essential oils have been suggested as a suitable alternative for controlling stored pests worldwide. However, very little is known about the physiological or behavioral responses induced by these compounds in insect populations that are resistant to traditional insecticides. Thus, this investigation evaluated the toxicity (including the impacts on population growth) as well as the locomotory and respiratory responses induced by clove, Syzygium aromaticum L., and cinnamon, Cinnamomum zeylanicum L., essential oils in Brazilian populations of the maize weevil Sitophilus zeamais. We used populations that are resistant to phosphine and pyrethroids (PyPhR), only resistant to pyrethroids (PyR1 and PyR2) or susceptible to both insecticide types (SUS). The PyPhR population was more tolerant to cinnamon essential oil, and its population growth rate was less affected by both oil types. Insects from this population reduced their respiratory rates (i.e., CO2 production) after being exposed to both oil types and avoided (in free choice-experiments) or reduced their mobility on essential oil-treated surfaces. The PyR1 and PyR2 populations reduced their respiratory rates, avoided (without changing their locomotory behavior in no-choice experiments) essential oil-treated surfaces and their population growth rates were severely affected by both oil types. Individuals from SUS population increased their mobility on surfaces that were treated with both oil types and showed the highest levels of susceptibility to these oils. Our findings indicate that S. zeamais populations that are resistant to traditional insecticides might have distinct but possibly overlapping mechanisms to mitigate the actions of essential oils and traditional insecticides.

  6. Laboratory and field efficacy of entomopathogenic fungi for the management of the sweetpotato weevil, Cylas formicarius (Coleoptera: Brentidae).

    PubMed

    Reddy, Gadi V P; Zhao, Zihua; Humber, Richard A

    2014-10-01

    The sweetpotato weevil, Cylas formicarius (F.) (Coleoptera: Brentidae), is one of the most important pests of sweet potatoes in the world. With free trade between the United States and the U.S.-controlled Mariana Islands, C. formicarius has spread along with this commodity. Because of the cryptic nature of the larvae and nocturnal activity of the adults, and the cancellation of long-residual pesticides, this pest has become increasingly difficult to control. Therefore, the present study sought to explore and to compare the effectiveness of Metarhizium brunneum F52 (90ml a.i./ha), Beauveria bassiana GHA (40ml a.i./ha), spinosad (90g a.i./ha), azadirachtin (1484ml a.i./ha), B. bassiana+M. brunneum (20ml a.i./ha+45ml a.i./ha), B. bassiana+azadirachtin (20ml a.i./ha+742ml a.i./ha), B. bassiana+spinosad (20ml a.i./ha+45ml a.i./ha), M. brunneum+azadirachtin (45ml a.i./ha+742ml a.i./ha) and M. brunneum+spinosad (45ml a.i./ha+45 grams a.i./ha) in controlling this pest in both the laboratory and the field. The treatment with B. bassiana+M. brunneum was the most effective in reducing tuber damage by C. formicarius, producing the highest yields. The most adult cadavers were found in plots treated with the combination of two fungi. This combined fungal formulation appears to be appropriate for the practical control of C. formicarius on sweet potatoes. PMID:25111763

  7. Diversity and infection prevalence of endosymbionts in natural populations of the chestnut weevil: relevance of local climate and host plants.

    PubMed

    Toju, Hirokazu; Fukatsu, Takema

    2011-02-01

    Many insects are ubiquitously associated with multiple endosymbionts, whose infection patterns often exhibit spatial and temporal variations. How such endosymbiont variations are relevant to local adaptation of the host organisms is of ecological interest. Here, we report a comprehensive survey of endosymbionts in natural populations of the chestnut weevil Curculio sikkimensis, whose larvae are notorious pests of cultivated chestnuts and also infest acorns of various wild oaks. From 968 insects representing 55 localities across the Japanese Archipelago and originating from 10 host plant species, we identified six distinct endosymbiont lineages, namely Curculioniphilus, Sodalis, Serratia, Wolbachia, Rickettsia and Spiroplasma, at different infection frequencies (96.7%, 12.8%, 82.3%, 82.5%, 28.2% and 6.8%, respectively) and with different geographical distribution patterns. Multiple endosymbiont infections were very common; 3.18±0.61 (ranging from 1.74 to 5.50) endosymbionts per insect on average in each of the local populations. Five pairs of endosymbionts (Curculioniphilus-Serratia, Curculioniphilus-Wolbachia, Sodalis-Rickettsia, Wolbachia-Rickettsia and Rickettsia-Spiroplasma) co-infected the same host individuals more frequently than expected, while infections with Serratia and Wolbachia were negatively correlated to each other. Infection frequencies of the endosymbionts were significantly correlated with climatic and ecological factors: for example, higher Sodalis, Wolbachia and Rickettsia infections at localities of higher temperature; lower Wolbachia and Rickettsia infections at localities of greater snowfall; and higher Curculioniphilus, Sodalis, Serratia, Wolbachia and Rickettsia infections on acorns than on chestnuts. These patterns are discussed in relation to potential host-endosymbiont co-evolution via local adaptation across geographical populations.

  8. Locomotory and physiological responses induced by clove and cinnamon essential oils in the maize weevil Sitophilus zeamais.

    PubMed

    Gonzales Correa, Yenis Del Carmen; Faroni, Lêda R A; Haddi, Khalid; Oliveira, Eugênio E; Pereira, Eliseu José G

    2015-11-01

    Plant essential oils have been suggested as a suitable alternative for controlling stored pests worldwide. However, very little is known about the physiological or behavioral responses induced by these compounds in insect populations that are resistant to traditional insecticides. Thus, this investigation evaluated the toxicity (including the impacts on population growth) as well as the locomotory and respiratory responses induced by clove, Syzygium aromaticum L., and cinnamon, Cinnamomum zeylanicum L., essential oils in Brazilian populations of the maize weevil Sitophilus zeamais. We used populations that are resistant to phosphine and pyrethroids (PyPhR), only resistant to pyrethroids (PyR1 and PyR2) or susceptible to both insecticide types (SUS). The PyPhR population was more tolerant to cinnamon essential oil, and its population growth rate was less affected by both oil types. Insects from this population reduced their respiratory rates (i.e., CO2 production) after being exposed to both oil types and avoided (in free choice-experiments) or reduced their mobility on essential oil-treated surfaces. The PyR1 and PyR2 populations reduced their respiratory rates, avoided (without changing their locomotory behavior in no-choice experiments) essential oil-treated surfaces and their population growth rates were severely affected by both oil types. Individuals from SUS population increased their mobility on surfaces that were treated with both oil types and showed the highest levels of susceptibility to these oils. Our findings indicate that S. zeamais populations that are resistant to traditional insecticides might have distinct but possibly overlapping mechanisms to mitigate the actions of essential oils and traditional insecticides. PMID:26615148

  9. Effect of Soil Moisture and a Surfactant on Entomopathogenic Nematode Suppression of the Pecan Weevil, Curculio caryae.

    PubMed

    Shapiro-Ilan, David I; Cottrell, Ted E; Brown, Ian; Gardner, Wayne A; Hubbard, Robert K; Wood, Bruce W

    2006-12-01

    Our overall goal was to investigate several aspects of pecan weevil, Curculio caryae, suppression with entomopathogenic nematodes. Specifically, our objectives were to: 1) determine optimum moisture levels for larval suppression, 2) determine suppression of adult C. caryae under field conditions, and 3) measure the effects of a surfactant on nematode efficacy. In the laboratory, virulence of Heterorhabditis megidis (UK211) and Steinernema carpocapsae (All) were tested in a loamy sand at gravimetric water contents of negative 0.01, 0.06, 0.3, 1.0, and 15 bars. Curculio caryae larval survival decreased as moisture levels increased. The nematode effect was most pronounced at -0.06 bars. At -0.01 bars, larval survival was

  10. Laboratory and field efficacy of entomopathogenic fungi for the management of the sweetpotato weevil, Cylas formicarius (Coleoptera: Brentidae).

    PubMed

    Reddy, Gadi V P; Zhao, Zihua; Humber, Richard A

    2014-10-01

    The sweetpotato weevil, Cylas formicarius (F.) (Coleoptera: Brentidae), is one of the most important pests of sweet potatoes in the world. With free trade between the United States and the U.S.-controlled Mariana Islands, C. formicarius has spread along with this commodity. Because of the cryptic nature of the larvae and nocturnal activity of the adults, and the cancellation of long-residual pesticides, this pest has become increasingly difficult to control. Therefore, the present study sought to explore and to compare the effectiveness of Metarhizium brunneum F52 (90ml a.i./ha), Beauveria bassiana GHA (40ml a.i./ha), spinosad (90g a.i./ha), azadirachtin (1484ml a.i./ha), B. bassiana+M. brunneum (20ml a.i./ha+45ml a.i./ha), B. bassiana+azadirachtin (20ml a.i./ha+742ml a.i./ha), B. bassiana+spinosad (20ml a.i./ha+45ml a.i./ha), M. brunneum+azadirachtin (45ml a.i./ha+742ml a.i./ha) and M. brunneum+spinosad (45ml a.i./ha+45 grams a.i./ha) in controlling this pest in both the laboratory and the field. The treatment with B. bassiana+M. brunneum was the most effective in reducing tuber damage by C. formicarius, producing the highest yields. The most adult cadavers were found in plots treated with the combination of two fungi. This combined fungal formulation appears to be appropriate for the practical control of C. formicarius on sweet potatoes.

  11. Re-description and first host and biology records of Entedon magnificus (Girault & Dodd) (Hymenoptera, Eulophidae), a natural enemy of Gonipterus weevils (Coleoptera, Curculionidae), a pest of Eucalyptus trees.

    PubMed

    Gumovsky, Alex; De Little, Dave; Rothmann, Sergio; Jaques, Lorena; Mayorga, Sandra Elizabeth Ide

    2015-01-01

    Entedon magnificus (Girault & Dodd) (Hymenoptera: Eulophidae, Entedoninae) is recorded as a gregarious larval endoparasitoid of Gonipterus weevils (Coleoptera: Curculionidae), significant pests of Eucalyptus trees. Entedon magnificus is re-described and illustrated based on females and males from Australia and Tasmania. PMID:26249097

  12. Re-description and first host and biology records of Entedon magnificus (Girault & Dodd) (Hymenoptera, Eulophidae), a natural enemy of Gonipterus weevils (Coleoptera, Curculionidae), a pest of Eucalyptus trees.

    PubMed

    Gumovsky, Alex; De Little, Dave; Rothmann, Sergio; Jaques, Lorena; Mayorga, Sandra Elizabeth Ide

    2015-05-19

    Entedon magnificus (Girault & Dodd) (Hymenoptera: Eulophidae, Entedoninae) is recorded as a gregarious larval endoparasitoid of Gonipterus weevils (Coleoptera: Curculionidae), significant pests of Eucalyptus trees. Entedon magnificus is re-described and illustrated based on females and males from Australia and Tasmania.

  13. Mitochondrial nucleotide variability in invasive populations of the root weevil Diaprepes abbreviatus (Coleoptera: Curculionidae) of Florida and preliminary assessment of Diaprepes sp. from Dominica.

    PubMed

    Ascunce, Marina S; Ernst, Joel A; Clark, Annemarie; Nigg, Herbert N

    2008-08-01

    Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae) is a root weevil introduced into the United States from the Caribbean in 1964. It is associated with >300 plants, including citrus, sugarcane, and potatoes. D. abbreviatus is widespread in Florida, and it has recently been detected in limited areas of California and Texas. The purpose of this research is to evaluate the utility of 16S ribosomal (16S rRNA) and cytochrome oxidase I (COI) mitochondrial markers for the delineation of genetic populations of D. abbreviatus in Florida and for the characterization of patterns of dispersion among these populations. We also assessed these markers as genetic tools for the clarification of taxonomic uncertainties in specimens from Dominica (Lesser Antilles). We analyzed 111 weevils from six Florida populations and six specimens from Dominica. In Florida, we found three haplotypes with only one haplotype in each population. Florida haplotypes differed by one to three nucleotide substitutions, possibly the result of a recent divergence from one source population or three different introductions from closely related populations from the Caribbean. In contrast, specimens from Dominica showed a high genetic variability with three 16S haplotypes and six unique COI haplotypes, delineating two mitochondrial clades. We show that these mitochondrial markers are useful for phylogeographic studies of D. abbreviatus.

  14. Purification, partial characterization and role in lipid transport to developing oocytes of a novel lipophorin from the cowpea weevil, Callosobruchus maculatus.

    PubMed

    Ximenes, A A; Oliveira, G A; Bittencourt-Cunha, P; Tomokyo, M; Leite, D B; Folly, E; Golodne, D M; Atella, G C

    2008-01-01

    Lipid transport in arthropods is achieved by highly specialized lipoproteins, which resemble those described in vertebrate blood. Here we describe purification and characterization of the lipid-apolipoprotein complex, lipophorin (Lp), from adults and larvae of the cowpea weevil Callosobruchus maculatus. We also describe the Lp-mediated lipid transfer to developing oocytes. Lps were isolated from homogenates of C. maculatus larvae and adults by potassio bromide gradient and characterized with respect to physicochemical properties and lipid content. The weevil Lp (465 kDa) and larval Lp (585 kDa), with hydrated densities of 1.22 and 1.14 g/mL, contained 34 and 56% lipids and 9 and 7% carbohydrates, respectively. In both Lps, mannose was the predominant monosaccharide detected by paper chromatography. SDS-PAGE revealed two apolipoproteins in each Lp with molecular masses of 225 kDa (apolipoprotein-I) and 79 kDa (apolipoprotein-II). The lipids were extracted and analyzed by thin-layer chromatography. The major phospholipids found were phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine in adult Lp, and phosphatidylcholine, phosphatidylethanolamine and sphingomyelin in larval Lp. Hydrocarbons, fatty acids and triacylglycerol were the major neutral lipids found in both Lps. Lps labeled in the protein moiety with radioactive iodine (125I-iodine) or in the lipid moiety with fluorescent lipids revealed direct evidence of endocytic uptake of Lps in live oocytes of C. maculatus.

  15. (1R,2S,6R)-Papayanal: a new male-specific volatile compound released by the guava weevil Conotrachelus psidii (Coleoptera: Curculionidae).

    PubMed

    Romero-Frías, Alicia; Murata, Yasuhiro; Simões Bento, José Maurício; Osorio, Coralia

    2016-05-01

    The guava weevil, Conotrachelus psidii is an aggressive pest of guava (Psidium guajava L.) that causes irreparable damages inside the fruit. The volatile compounds of male and female insects were separately collected by headspace solid-phase microextraction or with dynamic headspace collection on a polymer sorbent, and comparatively analyzed by GC-MS. (1R,2S,6R)-2-Hydroxymethyl-2,6-dimethyl-3-oxabicyclo[4.2.0]octane (papayanol), and (1R,2S,6R)-2,6-dimethyl-3-oxabicyclo[4.2.0]octane-2-carbaldehyde (papayanal) were identified (ratio of 9:1, respectively) as male-specific guava weevil volatiles. Papayanal structure was confirmed by comparison of spectroscopic (EIMS) and chromatographic (retention time) data with those of the synthetic pure compound. The behavioral response of the above-mentioned compounds was studied in a Y-tube olfactometer bioassay, and their role as aggregation pheromone candidate components was suggested in this species. PMID:26873673

  16. Inheritance of resistance to the bean-pod weevil (Apion godmani Wagner) in common beans from Mexico.

    PubMed

    Garza, R; Cardona, C; Singh, S P

    1996-03-01

    The bean-pod weevil (BPW), Apion godmani Wagner, often causes heavy losses in crops of common bean (Phaseolus vulgaris L.). Farmers need resistant bean cultivars to minimize losses, cut production costs, stabilize seed yield, and reduce pesticide use and consequent health hazards. To design effective breeding methods, breeders need new and better sources of resistance and increased knowledge of their modes of inheritance. We therefore: (1) compared sources of resistance to BPW, (2) studied the inheritance of resistance, and (3) determined whether the sources possess similar or different genes for BPW resistance. The following sources of resistance, originating from the Mexican highlands, were evaluated for 3 years at INIFAP-Santa Lucía de Prias, Texcoco, Mexico: 'Amarillo 153', 'Amarillo 169', 'Hidalgo 58', 'J 117', 'Pinto Texcoco', 'Pinto 168', and 'Puebla 36'. All except 'Puebla 36' were crossed with the susceptible cultivar 'Jamapa'. 'Amarillo 153' and 'Puebla 36' were crossed with another susceptible cultivar, 'Bayo Mex'. The parents, F1 hybrids, and F2 populations were evaluated for BPW damage in 1992. Backcrosses of the F1 of Jamapa/Pinto 168 to the respective susceptible and resistant parents were also evaluated in 1992. All seven resistant accessions were crossed in all possible combinations, excluding reciprocals. The resulting 21 F1 hybrids and 21 F2 populations were evaluated for BPW damage in 1994. 'J 117' had the highest level of resistance to BPW. 'Pinto Texcoco' and 'Puebla 36' had the highest mean damage score of all seven sources of resistance. The F1 hybrids between susceptible parents and resistant sources were generally intermediate. Two genes segregating independently controlled the BPW resistance in each accession. One gene, Agm, has no effect when present alone, whereas the other gene, Agr, alone conferred intermediate resistance. When both genes were present, resistance to BPW was higher. Based on mean BPW damage scores, all 21 F1 hybrids

  17. The African yam bean seed lectin affects the development of the cowpea weevil but does not affect the development of larvae of the legume pod borer.

    PubMed

    Machuka, J S; Okeola, O G; Chrispeels, M J; Jackai, L E

    2000-03-01

    Artificial feeding assays were used to study the effect of purified galactose-specific lectins from African yam beans (Sphenostylis stenocarpa) on development of larvae of the cowpea weevil, Callosobruchus maculatus (Coleoptera : Bruchidae) and the legume pod-borer, Maruca vitrata (Lepidoptera : Pyrialidae). Inhibition of development of C. maculatus was observed when larvae were fed on artificial cowpea seeds containing 0.2%, 2.0% and 5.0% (wt/wt) of dietary lectin. Larval mortality was between 30% and 88%, while delays in total developmental time ranged between 7 and 13 days. The lectin had no effect on development of larvae of M. vitrala, when tested through topical artificial diet incorporation assays, except at the extremely high dose of 35% dietary level.

  18. Assessment of electron beam-induced DNA damage in larvae of chestnut weevil, Curculio sikkimensis (Heller) (Coleoptera: Curculionidae) using comet assay

    NASA Astrophysics Data System (ADS)

    Todoriki, Setsuko; Hasan, Mahbub; Miyanoshita, Akihiro; Imamura, Taro; Hayashi, Toru

    2006-02-01

    Effect of electron beam treatment on DNA damage in mature larvae of chestnut weevil Curculio sikkimensis (Heller) was assessed using single-cell gel electrophoresis (DNA comet assay). Electrons at acceleration voltages of 0 (control), 300, 750, 1000, and 1500 kV at radiation doses of 1 and 4 kGy were used. Electron beam-treated chestnut larvae showed typical DNA fragmentation, compared with cells from non-treated ones which showed a more intact DNA. Investigations using the comet assay showed that the parameters including tail length, tail moment, olive tail moment as well as the quota of DNA damage at both the doses were significantly larger than the control batch larvae. Thus, this technique could contribute to analytical identification of an effective disinfestation and quarantine treatment.

  19. Lower temperature thresholds for oviposition and egg hatching of the red palm weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae), in a Mediterranean climate.

    PubMed

    Dembilio, O; Tapia, G V; Téllez, M M; Jacas, J A

    2012-02-01

    The red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae), is an economically important pest of palms worldwide. To better understand the phenology of R. ferrugineus populations in the Mediterranean basin, the objective of the present work has been to estimate the effect of temperatures within the range 10-25°C on the reproductive parameters of R. ferrugineus and to determine its lower temperature thresholds for oviposition and egg hatching. Our results confirm that oviposition in R. ferrugineus is strongly affected by temperature. Lower thresholds for oviposition and egg hatching (15.45° and 13.95°C, respectively) are below the mean monthly temperatures registered in winter in most of the northern shore of the Mediterranean basin. Under these circumstances, new palm infestations would be difficult during most of the winter. These results should be taken into account when planning some palm management practices, such as pruning or pesticide treatments, in areas under a Mediterranean climate.

  20. Mito-nuclear genetic comparison in a Wolbachia infected weevil: insights on reproductive mode, infection age and evolutionary forces shaping genetic variation

    PubMed Central

    2010-01-01

    Background Maternally inherited endosymbionts like Wolbachia pipientis are in linkage disequilibrium with the mtDNA of their hosts. Therefore, they can induce selective sweeps, decreasing genetic diversity over many generations. This sex ratio distorter, that is involved in the origin of parthenogenesis and other reproductive alterations, infects the parthenogenetic weevil Naupactus cervinus, a serious pest of ornamental and fruit plants. Results Molecular evolution analyses of mitochondrial (COI) and nuclear (ITS1) sequences from 309 individuals of Naupactus cervinus sampled over a broad range of its geographical distribution were carried out. Our results demonstrate lack of recombination in the nuclear fragment, non-random association between nuclear and mitochondrial genomes and the consequent coevolution of both genomes, being an indirect evidence of apomixis. This weevil is infected by a single Wolbachia strain, which could have caused a moderate bottleneck in the invaded population which survived the initial infection. Conclusions Clonal reproduction and Wolbachia infection induce the coevolution of bacterial, mitochondrial and nuclear genomes. The time elapsed since the Wolbachia invasion would have erased the traces of the demographic crash in the mtDNA, being the nuclear genome the only one that retained the signal of the bottleneck. The amount of genetic change accumulated in the mtDNA and the high prevalence of Wolbachia in all populations of N. cervinus agree with the hypothesis of an ancient infection. Wolbachia probably had great influence in shaping the genetic diversity of N. cervinus. However, it would have not caused the extinction of males, since sexual and asexual infected lineages coexisted until recent times. PMID:21050430

  1. Plasticity and Evolution of (+)-3-Carene Synthase and (−)-Sabinene Synthase Functions of a Sitka Spruce Monoterpene Synthase Gene Family Associated with Weevil Resistance*

    PubMed Central

    Roach, Christopher R.; Hall, Dawn E.; Zerbe, Philipp; Bohlmann, Jörg

    2014-01-01

    The monoterpene (+)-3-carene is associated with resistance of Sitka spruce against white pine weevil, a major North American forest insect pest of pine and spruce. High and low levels of (+)-3-carene in, respectively, resistant and susceptible Sitka spruce genotypes are due to variation of (+)-3-carene synthase gene copy number, transcript and protein expression levels, enzyme product profiles, and enzyme catalytic efficiency. A family of multiproduct (+)-3-carene synthase-like genes of Sitka spruce include the three (+)-3-carene synthases, PsTPS-3car1, PsTPS-3car2, PsTPS-3car3, and the (−)-sabinene synthase PsTPS-sab. Of these, PsTPS-3car2 is responsible for the relatively higher levels of (+)-3-carene in weevil-resistant trees. Here, we identified features of the PsTPS-3car1, PsTPS-3car2, PsTPS-3car3, and PsTPS-sab proteins that determine different product profiles. A series of domain swap and site-directed mutations, supported by structural comparisons, identified the amino acid in position 596 as critical for product profiles dominated by (+)-3-carene in PsTPS-3car1, PsTPS-3car2, and PsTPS-3car3, or (−)-sabinene in PsTPS-sab. A leucine in this position promotes formation of (+)-3-carene, whereas phenylalanine promotes (−)-sabinene. Homology modeling predicts that position 596 directs product profiles through differential stabilization of the reaction intermediate. Kinetic analysis revealed position 596 also plays a role in catalytic efficiency. Mutations of position 596 with different side chain properties resulted in a series of enzymes with different product profiles, further highlighting the inherent plasticity and potential for evolution of alternative product profiles of these monoterpene synthases of conifer defense against insects. PMID:25016016

  2. Out of the forest: past and present range expansion of a parthenogenetic weevil pest, or how to colonize the world successfully.

    PubMed

    Rodriguero, Marcela S; Lanteri, Analía A; Guzmán, Noelia V; Carús Guedes, Jerson V; Confalonieri, Viviana A

    2016-08-01

    Previous research revealed complex diversification patterns in the parthenogenetic weevil Naupactus cervinus. To understand the origin of clonal diversity and successful spreading of this weevil, we investigated its geographic origin and possible dispersal routes and whether parthenogens can persist in habitats under unsuitable environmental conditions. This study is based on samples taken throughout a broad area of the species' range. We used both mitochondrial and nuclear markers and applied phylogenetic and network analyses to infer possible relationships between haplotypes. Bayesian phylogeographic analyses and ecological niche modeling were used to investigate the processes that shaped genetic diversity and enabled the colonization of new geographic areas. Southeastern Brazil emerges as the original distribution area of N. cervinus. We detected two range expansions, one along natural corridors during the Pleistocene and the other in countries outside South America during recent times. Isolation due to climate shifts during the early Pleistocene led to diversification in two divergent clades, which probably survived in different refugia of the Paranaense Forest and the Paraná River delta. The origin of the clonal diversity was probably a complex process including mutational diversification, hybridization, and secondary colonization. The establishment of N. cervinus in areas outside its native range may indicate adaptation to drier and cooler conditions. Parthenogenesis would be advantageous for the colonization of new environments by preventing the breakup of successful gene combinations. As in other insect pests, the present distribution of N. cervinus results from both its evolutionary history and its recent history related to human activities. PMID:27551394

  3. Effects of an entomopathogen nematode on the immune response of the insect pest red palm weevil: Focus on the host antimicrobial response.

    PubMed

    Binda-Rossetti, Simona; Mastore, Maristella; Protasoni, Marina; Brivio, Maurizio F

    2016-01-01

    Relationships between parasites and hosts can be drastic, depending on the balance between parasite strategies and the efficiency of the host immune response. In the case of entomopathogenic nematodes and their insect hosts, we must also consider the role of bacterial symbionts, as the interaction among them is tripartite and each component plays a critical role in death or survival. We analyzed the effects induced by the nematode-bacteria complex Steinernema carpocapsae, against red palm weevil (RPW) larvae, Rhynchophorus ferrugineus. We examined the antimicrobial response of the insect when in the presence of nematocomplexes or of its symbionts, Xenorhabdus nematophila. In detail, we investigated the potential interference of live and dead S. carpocapsae, their isolated cuticles, live or dead bacterial symbionts and their lipopolysaccharides, on the synthesis and activity of host antimicrobial peptides. Our data indicate that both live nematodes and live bacterial symbionts are able to depress the host antimicrobial response. When nematodes or symbionts were killed, they lacked inhibitory properties, as detected by the presence of antimicrobial peptides (AMPs) in the host hemolymph and by assays of antimicrobial activity. Moreover, we isolated S. carpocapsae cuticles; when cuticles were injected into hosts they revealed evasive properties because they were not immunogenic and were not recognized by the host immune system. We observed that weevil AMPs did not damage X. nematophila, and the lipopolysaccharides purified from symbionts seemed to be non-immunogenic. We believe that our data provide more information on the biology of entomopathogenic nematodes, in particular concerning their role and the activity mediated by symbionts in the relationship with insect hosts.

  4. A novel β-fructofuranosidase in Coleoptera: Characterization of a β-fructofuranosidase from the sugarcane weevil, Sphenophorus levis.

    PubMed

    Pedezzi, Rafael; Fonseca, Fernando P P; Santos Júnior, Célio Dias; Kishi, Luciano T; Terra, Walter R; Henrique-Silva, Flávio

    2014-12-01

    β-fructofuranosidases or invertases (EC 3.2.1.26) catalyze the hydrolysis of sucrose into fructose and glucose. β-fructofuranosidases have been widely described in microorganisms, but were not known in the animal kingdom until very recently. There are studies reporting lepidopteran β-fructofuranosidases, but no β-fructofuranosidase gene sequence or encoding transcript has previously been identified in beetles. Considering the scarcity of functional studies on insect β-fructofuranosidases and their apparent non-occurrence among coleopterans, the aim of the present study was to investigate the occurrence and characterize a β-fructofuranosidase transcript identified in a cDNA library from the sugarcane weevil, Sphenophorus levis (Curculionidae). To validate that the β-fructofuranosidase sequence (herein denominated Sl-β-fruct) is indeed encoded by the S. levis genome, PCRs were performed using genomic DNA extracted from the larval fat body as well as DNA from the midgut with microbial content. Amplification of Sl-β-fruct gene using larval fat body DNA indicated its presence in the insect's genomic DNA. The Sl-β-fruct gene was cloned in Pichia pastoris to produce the recombinant enzyme (rSl-β-fruct). Molecular weight of the recombinant protein was about 64 kDa, indicating possible glycosylation, since the theoretical weight was 54.8 kDa. The substrate specificity test revealed that rSl-β-fruct hydrolyzes sucrose and raffinose, but not melibiose or maltose, thereby confirming invertase activity. The pH curve revealed greatest activity at pH 5.0, demonstrating rSl-β-fruct to be an acidic β-fructofuranosidase. Quantitative PCR (qRT-PCR) analyses indicated that the production of mRNA only occurs in the midgut and reaches the greatest expression level in 30-day-old larvae, which is the expected pattern for digestive enzymes. Chromatography of glycosidases from S. levis midguts showed two enzymes acting as β-fructofuranosidase, indicating the presence of a

  5. Response to water deficit and high temperature of transgenic peas (Pisum sativum L.) containing a seed-specific alpha-amylase inhibitor and the subsequent effects on pea weevil (Bruchus pisorum L.) survival.

    PubMed

    Sousa-Majer, Maria José de; Turner, Neil C; Hardie, Darryl C; Morton, Roger L; Lamont, Byron; Higgins, Thomas J V

    2004-02-01

    The effects of water deficit and high temperature on the production of alpha-amylase inhibitor 1 (alpha-AI-1) were studied in transgenic peas (Pisum sativum L.) that were developed to control the seed-feeding pea weevil (Bruchus pisorum L., Coleoptera: Bruchidae). Transgenic and non-transgenic plants were subjected to water-deficit and high-temperature treatments under controlled conditions in the glasshouse and growth cabinet, beginning 1 week after the first pods were formed. In the water-deficit treatments, the peas were either adequately watered (control) or water was withheld after first pod formation. The high-temperature experiments were performed in two growth cabinets, one maintained at 27/22 degrees C (control) and one at 32/27 degrees C day/night temperatures, with the vapour pressure deficit maintained at 1.3 kPa. The plants exposure to high temperatures and water deficit produced 27% and 79% fewer seeds, respectively, than the controls. In the transgenic peas the level of alpha-AI-1 as a percentage of total protein was not influenced by water stress, but was reduced on average by 36.3% (the range in two experiments was 11-50%) in the high-temperature treatment. Transgenic and non-transgenic pods of plants grown at 27/22 degrees C and 32/27 degrees C were inoculated with pea weevil eggs to evaluate whether the reduction in level of alpha-AI-1 in the transgenic pea seeds affected pea weevil development and survival. At the higher temperatures, 39% of adult pea weevil emerged, compared to 1.2% in the transgenic peas grown at the lower temperatures, indicating that high temperature reduced the protective capacity of the transgenic peas.

  6. Revision of the New World cycad weevils of the subtribe Allocorynina, with description of two new genera and three new subgenera (Coleoptera: Belidae: Oxycoryninae).

    PubMed

    O'brien, Charles W; Tang, William

    2015-01-01

    The taxonomy of the weevils inhabiting male cycad cones in the New World is reviewed. All species belong in a single subtribe, Allocorynina, of the family Belidae, subfamily Oxycoryninae and tribe Oxycorynini and are known to develop only in cones of the cycad genera Dioon and Zamia. Most species of Rhopalotria Chevrolat develop in male cones of Zamia ranging from Mexico, Belize, the Caribbean (Cuba, Isle of Youth, Cayman Islands, Jamaica and the Bahamas) to southern Florida, and one species in those of Dioon spinulosum in Mexico. Rhopalotria consists of three previously described species, two previously described genus-group names (treated herein as subgenera) and four new species described herein: subgenus Allocorynus Sharp with R. calonjei n. sp., R. furfuracea n. sp., R. mollis (Sharp) and R. vovidesi n. sp., and the nominate subgenus Rhopalotria with R. dimidiata Chevrolat, R. meerowi n. sp. and R. slossoni (Schaeffer). The species of Parallocorynus Voss develop only in cones of Dioon in Mexico, and the genus consists of one previously described species, the nominate subgenus and three new subgenera and 11 new species described herein: subgenus Dysicorynus n. subg. with P. andrewsi n. sp. and P. sonorensis n. sp., subgenus Eocorynus n. subg. with P. chemnicki n. sp. and P. schiblii n. sp., subgenus Neocorynus n. subg. with P. iglesiasi n. sp. and P. inexpectatus n. sp., and the nominate subgenus Parallocorynus with P. bicolor (Voss), P. gregoryi n. sp., P. jonesi n. sp., P. norstogi n. sp., P. perezfarrerai n. sp. and P. salasae n. sp. Two new genera are described, Protocorynus with one new species in Honduras, P. bontai, and Notorhopalotria with four new species ranging from Costa Rica to Colombia, N. montgomeryensis, N. panamensis, N. platysoma and N. taylori. Keys to genera, subgenera and species are provided. All of these weevils are believed to be involved in pollination of their host cycads. PMID:26249478

  7. Identification of Proteins Modulated in the Date Palm Stem Infested with Red Palm Weevil (Rhynchophorus ferrugineus Oliv.) Using Two Dimensional Differential Gel Electrophoresis and Mass Spectrometry.

    PubMed

    Rasool, Khawaja Ghulam; Khan, Muhammad Altaf; Aldawood, Abdulrahman Saad; Tufail, Muhammad; Mukhtar, Muhammad; Takeda, Makio

    2015-08-17

    A state of the art proteomic methodology using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI TOF) has been employed to characterize peptides modulated in the date palm stem subsequent to infestation with red palm weevil (RPW). Our analyses revealed 32 differentially expressed peptides associated with RPW infestation in date palm stem. To identify RPW infestation associated peptides (I), artificially wounded plants (W) were used as additional control beside uninfested plants, a conventional control (C). A constant unique pattern of differential expression in infested (I), wounded (W) stem samples compared to control (C) was observed. The upregulated proteins showed relative fold intensity in order of I > W and downregulated spots trend as W > I, a quite interesting pattern. This study also reveals that artificially wounding of date palm stem affects almost the same proteins as infestation; however, relative intensity is quite lower than in infested samples both in up and downregulated spots. All 32 differentially expressed spots were subjected to MALDI-TOF analysis for their identification and we were able to match 21 proteins in the already existing databases. Relatively significant modulated expression pattern of a number of peptides in infested plants predicts the possibility of developing a quick and reliable molecular methodology for detecting plants infested with date palm.

  8. Cytogenetic analyses using C-banding and DAPI/CMA3 staining of four populations of the maize weevil Sitophilus zeamais Motschulsky, 1855 (Coleoptera, Curculionidae)

    PubMed Central

    da Silva, Alexandra A.; Braga, Lucas S.; Guedes, Raul Narciso C.; Tavares, Mara G.

    2015-01-01

    Abstract Cytogenetic data avalaible for the maize weevil Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae), one of the most destructive pests of stored cereal grains, are controversial. Earlier studies focused on single populations and emphasized chromosome number and sex determination system. In this paper, the karyotypes of four populations of Sitophilus zeamais were characterized by conventional staining, C-banding and sequential staining with the fluorochromes chromomycin-A3/4-6-diamidino-2-phenylindole (CMA3/DAPI). The analyses of metaphases obtained from the cerebral ganglia of last instar larvae and the testes of adults showed that the species had 2n = 22 chromosomes, with 10 autosomal pairs and a sex chromosome pair (XX in females and Xyp in males). Chromosome number, however, ranged from 2n = 22 to 26 due to the presence of 0–4 supernumerary chromosomes in individuals from the populations of Viçosa, Unai and Porto Alegre. With the exception of the Y chromosome, which was dot-like, all other chromosomes of this species were metacentric, including the supernumeraries. The heterochromatin was present in the centromeric regions of all autosomes and in the centromere of the X chromosome. The B chromosomes were partially or totally heterochromatic, and the Y chromosome was euchromatic. The heterochromatic regions were labeled with C-banding and DAPI, which showed that they were rich in AT base pairs. PMID:25893077

  9. Phylogenetic analysis of the complete mitogenome sequence of the raspberry weevil, Aegorhinus superciliosus (Coleoptera: Curculionidae), supports monophyly of the tribe Aterpini.

    PubMed

    Cabrera-Brandt, Marco A; Gaitán-Espitia, Juan D

    2015-10-25

    The superfamily Curculionoidea is one of the most diverse groups of insects in the world, including many species which are crop pests. Within this group, the native raspberry weevil, Aegorhinus superciliosus (Guérin, 1830), is an important pest in blueberry and raspberry fields in southern South America. Using a 454 sequencing approach, we sequenced and annotated the mitogenome of A. superciliosus, it, providing the first such information for any species in the tribe Aterpini, subfamily Cyclominae. The assembled mitogenome is a circular DNA molecule 15,121bp in length containing all 37 genes normally found in metazoans. Mitogenome organization and transcriptional orientation in A. superciliosus showed the same pattern that characterizes the suborder Polyphaga. Bayesian and Maximum Likelihood phylogenetic analyses supported the monophyly of the tribe Aterpini and the subfamily Cyclominae, recovering this clade in a sister group relationship with Entiminae and Hyperinae. The monophyly of these three subfamilies defines a critical transition to an ectophagous lifestyle in the larvae, from an ancestrally endophagous larval lifestyle in all other lineages. The sequenced mitogenome of A. superciliosus can provide basic data for future studies investigating population history, molecular systematics, stress ecophysiology and phylogeography.

  10. Phylogeography of Phytophagous Weevils and Plant Species in Broadleaved Evergreen Forests: A Congruent Genetic Gap between Western and Eastern Parts of Japan

    PubMed Central

    Aoki, Kyoko; Kato, Makoto; Murakami, Noriaki

    2011-01-01

    The Quaternary climate cycles played an important role in shaping the distribution of biodiversity among current populations, even in warm-temperate zones, where land was not covered by ice sheets. We focused on the Castanopsis-type broadleaved evergreen forest community in Japan, which characterizes the biodiversity and endemism of the warm-temperate zone. A comparison of the phylogeographic patterns of three types of phytophagous weevils associated with Castanopsis (a host-specific seed predator, a generalist seed predator, and a host-specific leaf miner) and several other plant species inhabiting the forests revealed largely congruent patterns of genetic differentiation between western and eastern parts of the main islands of Japan. A genetic gap was detected in the Kii Peninsula to Chugoku-Shikoku region, around the Seto Inland Sea. The patterns of western-eastern differentiation suggest past fragmentation of broadleaved evergreen forests into at least two separate refugia consisting of the southern parts of Kyushu to Shikoku and of Kii to Boso Peninsula. Moreover, the congruent phylogeographic patterns observed in Castanopsis and the phytophagous insect species imply that the plant-herbivore relationship has been largely maintained since the last glacial periods. These results reinforce the robustness of the deduced glacial and postglacial histories of Castanopsis-associated organisms. PMID:26467618

  11. Identification of Proteins Modulated in the Date Palm Stem Infested with Red Palm Weevil (Rhynchophorus ferrugineus Oliv.) Using Two Dimensional Differential Gel Electrophoresis and Mass Spectrometry

    PubMed Central

    Rasool, Khawaja Ghulam; Khan, Muhammad Altaf; Aldawood, Abdulrahman Saad; Tufail, Muhammad; Mukhtar, Muhammad; Takeda, Makio

    2015-01-01

    A state of the art proteomic methodology using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI TOF) has been employed to characterize peptides modulated in the date palm stem subsequent to infestation with red palm weevil (RPW). Our analyses revealed 32 differentially expressed peptides associated with RPW infestation in date palm stem. To identify RPW infestation associated peptides (I), artificially wounded plants (W) were used as additional control beside uninfested plants, a conventional control (C). A constant unique pattern of differential expression in infested (I), wounded (W) stem samples compared to control (C) was observed. The upregulated proteins showed relative fold intensity in order of I > W and downregulated spots trend as W > I, a quite interesting pattern. This study also reveals that artificially wounding of date palm stem affects almost the same proteins as infestation; however, relative intensity is quite lower than in infested samples both in up and downregulated spots. All 32 differentially expressed spots were subjected to MALDI-TOF analysis for their identification and we were able to match 21 proteins in the already existing databases. Relatively significant modulated expression pattern of a number of peptides in infested plants predicts the possibility of developing a quick and reliable molecular methodology for detecting plants infested with date palm. PMID:26287180

  12. Multidisciplinary fingerprints: forensic reconstruction of an insect reinvasion

    PubMed Central

    Kim, Kyung Seok; Jones, Gretchen D.; Westbrook, John K.; Sappington, Thomas W.

    2010-01-01

    An unexpected outbreak of boll weevils, Anthonomus grandis, an insect pest of cotton, across the Southern Rolling Plains (SRP) eradication zone of west-central Texas, USA, was detected soon after passage of Tropical Storm Erin through the Winter Garden district to the south on 16 August 2007. The synchrony and broad geographic distribution of the captured weevils suggest that long-distance dispersal was responsible for the reinvasion. We integrated three types of assessment to reconstruct the geographic origin of the immigrants: (i) DNA fingerprinting; (ii) pollen fingerprinting; and (iii) atmospheric trajectory analysis. We hypothesized the boll weevils originated in the Southern Blacklands zone near Cameron, or in the Winter Garden district near Uvalde, the nearest regions with substantial populations. Genetic tests broadly agree that the immigrants originated southeast of the SRP zone, probably in regions represented by Uvalde or Weslaco. The SRP pollen profile from weevils matched that of Uvalde better than that of Cameron. Wind trajectories supported daily wind-aided dispersal of weevils from the Uvalde region to the SRP from 17 to 24 August, but failed to support migration from the Cameron region. Taken together the forensic evidence strongly implicates the Winter Garden district near Uvalde as the source of reinvading boll weevils. PMID:19828497

  13. An integrated genomic, proteomic and biochemical analysis of (+)-3-carene biosynthesis in Sitka spruce (Picea sitchensis) genotypes that are resistant or susceptible to white pine weevil.

    PubMed

    Hall, Dawn E; Robert, Jeanne A; Keeling, Christopher I; Domanski, Dominik; Quesada, Alfonso Lara; Jancsik, Sharon; Kuzyk, Michael A; Hamberger, Britta; Borchers, Christoph H; Bohlmann, Jörg

    2011-03-01

    Conifers are extremely long-lived plants that have evolved complex chemical defenses in the form of oleoresin terpenoids to resist attack from pathogens and herbivores. In these species, terpenoid diversity is determined by the size and composition of the terpene synthase (TPS) gene family and the single- and multi-product profiles of these enzymes. The monoterpene (+)-3-carene is associated with resistance of Sitka spruce (Picea sitchensis) to white pine weevil (Pissodes strobi). We used a combined genomic, proteomic and biochemical approach to analyze the (+)-3-carene phenotype in two contrasting Sitka spruce genotypes. Resistant trees produced significantly higher levels of (+)-3-carene than susceptible trees, in which only trace amounts were detected. Biosynthesis of (+)-3-carene is controlled, at the genome level, by a small family of closely related (+)-3-carene synthase (PsTPS-3car) genes (82-95% amino acid sequence identity). Transcript profiling identified one PsTPS-3car gene (PsTPS-3car1) that is expressed in both genotypes, one gene (PsTPS-3car2) that is expressed only in resistant trees, and one gene (PsTPS-3car3) that is expressed only in susceptible trees. The PsTPS-3car2 gene was not detected in genomic DNA of susceptible trees. Target-specific selected reaction monitoring confirmed this pattern of differential expression of members of the PsTPS-3car family at the proteome level. Kinetic characterization of the recombinant PsTPS-3car enzymes identified differences in the activities of PsTPS-3car2 and PsTPS-3car3 as a factor contributing to the different (+)-3-carene profiles of resistant and susceptible trees. In conclusion, variation of the (+)-3-carene phenotype is controlled by copy number variation of PsTPS-3car genes, variation of gene and protein expression, and variation in catalytic efficiencies.

  14. Influence of Two Acyclic Homoterpenes (Tetranorterpenes) on the Foraging Behavior of Anthonomus grandis Boh.

    PubMed

    Magalhães, D M; Borges, M; Laumann, R A; Woodcock, C M; Pickett, J A; Birkett, M A; Blassioli-Moraes, Maria Carolina

    2016-04-01

    Previous studies have shown that the boll weevil, Anthonomus grandis, is attracted to constitutive and conspecific herbivore-induced cotton volatiles, preferring the blend emitted by cotton at the reproductive over the vegetative stage. Moreover, this preference was paralleled by the release of the acyclic homoterpenes (tetranorterpenes) (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in Delta Opal cotton being higher at the vegetative than at the reproductive stage. Here, we evaluated whether this difference in release of acyclic homoterpenes also occurred in other cotton varieties, and if boll weevils could recognize these compounds as indicators of a specific cotton phenological stage. Results showed that cotton genotypes CNPA TB-90, BRS-293 and Delta Opal all produced higher levels of DMNT and TMTT at the vegetative stage than at the reproductive stage and that these homoterpenes allowed for principal component analysis separation of volatiles produced by the two phenological stages. Electroantennograms confirmed boll weevil antennal responses to DMNT and TMTT. Behavioral assays, using Y-tube olfactometers, showed that adding synthetic homoterpenes to reproductive cotton volatiles (mimicking cotton at the vegetative stage in terms of homoterpene levels) resulted in reduced attraction to boll weevils compared to that to unmodified reproductive cotton. Weevils showed no preference when given a choice between plants at the vegetative stage and the vegetative stage-mimicked plant. Altogether, the results show that DMNT and TMTT are used by boll weevils to distinguish between cotton phenological stages. PMID:27105878

  15. Effects of image spatial and radiometric resolutions on the detection of cotton plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate and timely detection of volunteer and regrowth cotton plants is important for the eradication of boll weevils in south Texas. Airborne remote sensing imagery has the potential to identify volunteer and regrowth cotton plants over large geographic regions. The objective of this study was to ...

  16. 7 CFR 771.6 - Environmental requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 7 2014-01-01 2014-01-01 false Environmental requirements. 771.6 Section 771.6... AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.6 Environmental requirements. No loan will be made until all Federal and state statutory and regulatory environmental requirements have...

  17. 7 CFR 771.6 - Environmental requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Environmental requirements. 771.6 Section 771.6... AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.6 Environmental requirements. No loan will be made until all Federal and state statutory and regulatory environmental requirements have...

  18. Catolaccus grandis (Burks)(Hymenoptera: Pteromalidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Catolaccus grandis is an ectoparasitoid of the boll weevil classified initially within the genus Heterolaccus (Burks 1954). It was first introduced to the U.S. during the early 1970’s and released in experimental fields in Mississippi State, MS (Johnson et al. 1973). Researchers observed encouraging...

  19. 7 CFR 771.4 - Eligibility requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Eligibility requirements. 771.4 Section 771.4 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.4 Eligibility requirements. (a)...

  20. 7 CFR 771.12 - Funding applications.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 7 2013-01-01 2013-01-01 false Funding applications. 771.12 Section 771.12 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.12 Funding applications. Loan...

  1. 7 CFR 771.12 - Funding applications.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Funding applications. 771.12 Section 771.12 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.12 Funding applications. Loan...

  2. 7 CFR 771.12 - Funding applications.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Funding applications. 771.12 Section 771.12 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.12 Funding applications. Loan...

  3. 7 CFR 771.12 - Funding applications.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Funding applications. 771.12 Section 771.12 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.12 Funding applications. Loan...

  4. 7 CFR 771.12 - Funding applications.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 7 2014-01-01 2014-01-01 false Funding applications. 771.12 Section 771.12 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.12 Funding applications. Loan...

  5. 7 CFR 771.8 - Other Federal, State, and local requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Other Federal, State, and local requirements. 771.8 Section 771.8 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.8 Other Federal,...

  6. 7 CFR 771.8 - Other Federal, State, and local requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Other Federal, State, and local requirements. 771.8 Section 771.8 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.8 Other Federal,...

  7. 7 CFR 771.8 - Other Federal, State, and local requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 7 2014-01-01 2014-01-01 false Other Federal, State, and local requirements. 771.8 Section 771.8 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.8 Other Federal,...

  8. 7 CFR 771.6 - Environmental requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Environmental requirements. 771.6 Section 771.6... AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.6 Environmental requirements. No loan will be made until all Federal and state statutory and regulatory environmental requirements have...

  9. 7 CFR 771.6 - Environmental requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Environmental requirements. 771.6 Section 771.6... AGRICULTURE SPECIAL PROGRAMS BOLL WEEVIL ERADICATION LOAN PROGRAM § 771.6 Environmental requirements. No loan will be made until all Federal and state statutory and regulatory environmental requirements have...

  10. On the identity of some weevil species described by Johann Christian Fabricius (1745-1808) in the Museum of Zoology of Copenhagen (Coleoptera, Cucujoidea, Curculionoidea, Tenebrionoidea).

    PubMed

    Alonso-Zarazaga, Miguel A

    2014-01-01

    The types of thirty-two nominal weevil species described by Johann Christian Fabricius are reviewed and lecto- and paralectotypes are designated for twenty-two of them. A neotype is designated for Curculiosticticus Fabricius, 1777. Protapionvaripes (Germar, 1817) is declared a nomen protectum over Curculioflavipes Fabricius, 1775. Based on a study of syntypes, Rhinomacercurculioides Fabricius, 1781 is confirmed as a member of Mycterus (Mycteridae), Bruchusundatus Fabricius, 1787 is tentatively transferred to Erotylidae, Curculiofulvirostris Fabricius, 1787 and Anthribusroboris Fabricius, 1798 are confirmed as members of Salpingus (Salpingidae), and Brachyceruscristatus Fabricius, 1798 is transferred to Tenebrionidae. Based on lectotype designation, Curculiocaninus Fabricius, 1792 is confirmed as a synonym of Sitonalineatus (Linnaeus, 1758) and Curculioinnocuus Fabricius, 1802 as a synonym of Cneorhinusbarcelonicus (Herbst, 1797). Bruchusrufipes Fabricius, 1792 is not considered an available species name, but a later use of Bruchusrufipes Olivier, 1790. Cossonusincisus Pascoe, 1885 is reinstated as valid from synonymy under Cossonusilligeri Champion, 1909 and Cossonusvulneratus Illiger, 1805 from synonymy under Cossonuscanaliculatus (Fabricius, 1792) (a primary homonym of Curculiocanaliculatus Olivier, 1791). Cossonuscanaliculatus Fabricius, 1802 is a secondary homonym of the former and is replaced with Cossonusincisus. Salpingusfulvirostris (Fabricius, 1787) is reinstated as valid from synonymy under Salpingusplanirostris (Fabricius, 1787), a primary homonym of Curculioplanirostris Piller & Mitterpacher, 1783. The following new combinations are proposed: Brachysomuserinaceus (Fabricius, 1802) (from Curculio), Bronchusferus (Gyllenhal, 1840) (from Hipporhinus), Bronchusglandifer (Fabricius, 1792) (from Curculio), Bronchusnivosus (Sparrman, 1785) (from Curculio), Bronchussparrmani (Gyllenhal, 1833) (from Hipporhinus), Coelocephalapionatrirostre (Fabricius, 1802

  11. A Rapid Decision Sampling Plan for Implementing Area—Wide Management of the Red Palm Weevil, Rhynchophorus ferrugineus, in Coconut Plantations of India

    PubMed Central

    Faleiro, J. R.; Ashok Kumar, J.

    2008-01-01

    The red palm weevil Rhynchophorus ferrugineus Olivier (Curculionidae/Rhynchophoridae/Dryophthoridae) is a lethal pest of young coconut palms, Cocos nucifera L. (Arecales: Arecaceae), with a highly aggregated population distribution pattern. R. ferrugineus is managed in several coconut growing countries using area-wide pheromone based programmes that need a substantial commitment of funds over a period of time. Often, decisions to implement area-wide management of R. ferrugineus are based on pheromone trap captures in surveillance traps and or infestation reports. Implementing area-wide management of this pest on the basis of such data can be inaccurate, as it may either under or over estimate the pest intensity in the field. This study presents sampling plans for rapid and accurate classification of R. ferrugineus infestation in coconut plantations of India by inspecting palms to detect infestation in a sequence until a decision to either implement or not to initiate area-wide management of R. ferrugineus can be made. The sampling plans are based on a common aggregation index of 3.45, assumed action threshold values of either 1.0 (plan A) or 0.5 (plan B) per cent infested palms and a risk factor of making the wrong decision set at 0.05. Using plans A and B, if the cummulative number of infested palms in a young 1 hectare coconut plantation is zero out of 150 palms for both plans, then area-wide management is not required, while on the other hand, if the cummulative number of infested palms for the same area is 6 (plan A), or 5 (plan B), then area-wide management of R. ferrugineus is essential. The proposed sampling plans are efficient tools in decision making, particularly at very low and high levels of infestation and can also be used to assess the performance of R. ferrugineus IPM programmes that are in progress. These plans not only save time and money as only a small area needs to be sampled to arrive at a correct decision, but are also efficient in rating the

  12. A rapid decision sampling plan for implementing area-wide management of the red palm weevil, Rhynchophorus ferrugineus, in coconut plantations of India.

    PubMed

    Faleiro, J R; Ashok Kumar, J

    2008-01-01

    The red palm weevil Rhynchophorus ferrugineus Olivier (Curculionidae/Rhynchophoridae/Dryophthoridae) is a lethal pest of young coconut palms, Cocos nucifera L. (Arecales: Arecaceae), with a highly aggregated population distribution pattern. R. ferrugineus is managed in several coconut growing countries using area-wide pheromone based programmes that need a substantial commitment of funds over a period of time. Often, decisions to implement area-wide management of R. ferrugineus are based on pheromone trap captures in surveillance traps and or infestation reports. Implementing area-wide management of this pest on the basis of such data can be inaccurate, as it may either under or over estimate the pest intensity in the field. This study presents sampling plans for rapid and accurate classification of R. ferrugineus infestation in coconut plantations of India by inspecting palms to detect infestation in a sequence until a decision to either implement or not to initiate area-wide management of R. ferrugineus can be made. The sampling plans are based on a common aggregation index of 3.45, assumed action threshold values of either 1.0 (plan A) or 0.5 (plan B) per cent infested palms and a risk factor of making the wrong decision set at 0.05. Using plans A and B, if the cumulative number of infested palms in a young 1 hectare coconut plantation is zero out of 150 palms for both plans, then area-wide management is not required, while on the other hand, if the cumulative number of infested palms for the same area is 6 (plan A), or 5 (plan B), then area-wide management of R. ferrugineus is essential. The proposed sampling plans are efficient tools in decision making, particularly at very low and high levels of infestation and can also be used to assess the performance of R. ferrugineus IPM programmes that are in progress. These plans not only save time and money as only a small area needs to be sampled to arrive at a correct decision, but are also efficient in rating the

  13. Cumulative impact of a clover cover crop on the persistence and efficacy of Beauveria bassiana in suppressing the pecan weevil (Coleoptera: Curculionidae).

    PubMed

    Shapiro-Ilan, David I; Gardner, Wayne A; Wells, Lenny; Wood, Bruce W

    2012-04-01

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan. Endemic levels of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin can occur in pecan orchards and contribute to natural control of C. caryae. Commercial formulations of the fungus can also be applied for suppression of C. caryae. We hypothesized that a clover cover crop enhances B. bassiana efficacy and persistence (e.g., by protecting the fungus against abiotic environmental stresses). The hypothesis was tested by conducting field trials in a pecan orchard in Byron, GA, in 2009 and 2010. The study included four treatments arranged in a factorial with two levels of fungus (endemic fungus only, and application of a commercial B. bassiana product), and two levels of clover (white clover, Trifolium repens L., and no clover). Fungal persistence was measured by determining the number of CFUs per gram of soil over time (during 42 d postapplication of B. bassiana in 2009 and 29 d in 2010). Efficacy was measured by capturing naturally emerging C. caryae and subsequently determining mortality and mycosis (over 24 d in 2009 and 17 d in 2010). In 2009, greater prevalence of B. bassiana conidia was detected in plots receiving fungal applications compared with no fungus applications, and no clear effect of clover was observed in plots receiving B. bassiana applications in either year. In 2010, B. bassiana prevalence in the endemic fungus plus clover treatment was higher than fungus without clover, and was similar to plots receiving additional B. bassiana applications. Given that we observed enhanced persistence of endemic B. bassiana in 2010 but not 2009, the impact of clover appears to be a cumulative effect. Mortality of C. caryae (averaged over the sampling periods) ranged between 68-74% in plots receiving B. bassiana applications and 51-56% in plots with endemic fungus only. C. caryae mortality and mycosis data also provided evidence that endemic B. bassiana efficacy was enhanced by clover

  14. On the identity of some weevil species described by Johann Christian Fabricius (1745–1808) in the Museum of Zoology of Copenhagen (Coleoptera, Cucujoidea, Curculionoidea, Tenebrionoidea)

    PubMed Central

    Alonso-Zarazaga, Miguel A.

    2014-01-01

    Abstract The types of thirty-two nominal weevil species described by Johann Christian Fabricius are reviewed and lecto- and paralectotypes are designated for twenty-two of them. A neotype is designated for Curculio sticticus Fabricius, 1777. Protapion varipes (Germar, 1817) is declared a nomen protectum over Curculio flavipes Fabricius, 1775. Based on a study of syntypes, Rhinomacer curculioides Fabricius, 1781 is confirmed as a member of Mycterus (Mycteridae), Bruchus undatus Fabricius, 1787 is tentatively transferred to Erotylidae, Curculio fulvirostris Fabricius, 1787 and Anthribus roboris Fabricius, 1798 are confirmed as members of Salpingus (Salpingidae), and Brachycerus cristatus Fabricius, 1798 is transferred to Tenebrionidae. Based on lectotype designation, Curculio caninus Fabricius, 1792 is confirmed as a synonym of Sitona lineatus (Linnaeus, 1758) and Curculio innocuus Fabricius, 1802 as a synonym of Cneorhinus barcelonicus (Herbst, 1797). Bruchus rufipes Fabricius, 1792 is not considered an available species name, but a later use of Bruchus rufipes Olivier, 1790. Cossonus incisus Pascoe, 1885 is reinstated as valid from synonymy under Cossonus illigeri Champion, 1909 and Cossonus vulneratus Illiger, 1805 from synonymy under Cossonus canaliculatus (Fabricius, 1792) (a primary homonym of Curculio canaliculatus Olivier, 1791). Cossonus canaliculatus Fabricius, 1802 is a secondary homonym of the former and is replaced with Cossonus incisus. Salpingus fulvirostris (Fabricius, 1787) is reinstated as valid from synonymy under Salpingus planirostris (Fabricius, 1787), a primary homonym of Curculio planirostris Piller & Mitterpacher, 1783. The following new combinations are proposed: Brachysomus erinaceus (Fabricius, 1802) (from Curculio), Bronchus ferus (Gyllenhal, 1840) (from Hipporhinus), Bronchus glandifer (Fabricius, 1792) (from Curculio), Bronchus nivosus (Sparrman, 1785) (from Curculio), Bronchus sparrmani (Gyllenhal, 1833) (from Hipporhinus

  15. Black Vine and Other Weevils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Otiorhynchus sulcatus and other members of the genus are severe pests of field and container-grown rhododendron and azalea. In order to manage these pests effectively, growers must have a firm understanding of their life cycle and behavior. Proper identification of the pest complex present at the n...

  16. Conifer defence against insects: microarray gene expression profiling of Sitka spruce (Picea sitchensis) induced by mechanical wounding or feeding by spruce budworms (Choristoneura occidentalis) or white pine weevils (Pissodes strobi) reveals large-scale changes of the host transcriptome.

    PubMed

    Ralph, Steven G; Yueh, Hesther; Friedmann, Michael; Aeschliman, Dana; Zeznik, Jeffrey A; Nelson, Colleen C; Butterfield, Yaron S N; Kirkpatrick, Robert; Liu, Jerry; Jones, Steven J M; Marra, Marco A; Douglas, Carl J; Ritland, Kermit; Bohlmann, Jörg

    2006-08-01

    Conifers are resistant to attack from a large number of potential herbivores or pathogens. Previous molecular and biochemical characterization of selected conifer defence systems support a model of multigenic, constitutive and induced defences that act on invading insects via physical, chemical, biochemical or ecological (multitrophic) mechanisms. However, the genomic foundation of the complex defence and resistance mechanisms of conifers is largely unknown. As part of a genomics strategy to characterize inducible defences and possible resistance mechanisms of conifers against insect herbivory, we developed a cDNA microarray building upon a new spruce (Picea spp.) expressed sequence tag resource. This first-generation spruce cDNA microarray contains 9720 cDNA elements representing c. 5500 unique genes. We used this array to monitor gene expression in Sitka spruce (Picea sitchensis) bark in response to herbivory by white pine weevils (Pissodes strobi, Curculionidae) or wounding, and in young shoot tips in response to western spruce budworm (Choristoneura occidentalis, Lepidopterae) feeding. Weevils are stem-boring insects that feed on phloem, while budworms are foliage feeding larvae that consume needles and young shoot tips. Both insect species and wounding treatment caused substantial changes of the host plant transcriptome detected in each case by differential gene expression of several thousand array elements at 1 or 2 d after the onset of treatment. Overall, there was considerable overlap among differentially expressed gene sets from these three stress treatments. Functional classification of the induced transcripts revealed genes with roles in general plant defence, octadecanoid and ethylene signalling, transport, secondary metabolism, and transcriptional regulation. Several genes involved in primary metabolic processes such as photosynthesis were down-regulated upon insect feeding or wounding, fitting with the concept of dynamic resource allocation in plant

  17. Insecticide activity of essential oils of Mentha longifolia, Pulicaria gnaphalodes and Achillea wilhelmsii against two stored product pests, the flour beetle, Tribolium castaneum, and the cowpea weevil, Callosobruchus maculatus.

    PubMed

    Khani, Abbas; Asghari, Javad

    2012-01-01

    Essential oils extracted from the foliage of Mentha longifolia (L.) (Lamiales: Lamiaceae) and Pulicaria gnaphalodes Ventenat (Asterales: Asteraceae), and flowers of Achillea wilhelmsii C. Koch (Asterales: Asteraceae) were tested in the laboratory for volatile toxicity against two storedproduct insects, the flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) and the cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae). The chemical composition of the isolated oils was examined by gas chromatography-mass spectrometry. InM longifolia, the major compounds were piperitenon (43.9%), tripal (14.3%), oxathiane (9.3%), piperiton oxide (5.9%), and d-limonene (4.3%). In P. gnaphalodes, the major compounds were chrysanthenyl acetate (22.38%), 2L -4L-dihydroxy eicosane (18.5%), verbenol (16.59%), dehydroaromadendrene (12.54%), β-pinen (6.43%), and 1,8 cineol (5.6%). In A. wilhelmsii, the major compounds were 1,8 cineole (13.03%), caranol (8.26%), alpha pinene (6%), farnesyl acetate (6%), and p-cymene (6%). C maculatus was more susceptible to the tested plant products than T castaneum. The oils of the three plants displayed the same insecticidal activity against C. maculatus based on LC(50) values (between 1.54µl/L air in P. gnaphalodes, and 2.65 µl/L air in A. wilhelmsii). While the oils of A. wilhelmsii and M. longifolia showed the same strong insecticidal activity against T. castaneum (LC(50) = 10.02 and 13.05 µl/L air, respectively), the oil of P. gnaphalodes revealed poor activity against the insect (LC(50) = 297.9 µl/L air). These results suggested that essential oils from the tested plants could be used as potential control agents for stored-product insects.

  18. Insecticide Activity of Essential Oils of Mentha longifolia, Pulicaria gnaphalodes and Achillea wilhelmsii Against Two Stored Product Pests, the Flour Beetle, Tribolium castaneum, and the Cowpea Weevil, Callosobruchus maculatus

    PubMed Central

    Khani, Abbas; Asghari, Javad

    2012-01-01

    Essential oils extracted from the foliage of Mentha longifolia (L.) (Lamiales: Lamiaceae) and Pulicaria gnaphalodes Ventenat (Asterales: Asteraceae), and flowers of Achillea wilhelmsii C. Koch (Asterales: Asteraceae) were tested in the laboratory for volatile toxicity against two storedproduct insects, the flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) and the cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae). The chemical composition of the isolated oils was examined by gas chromatography-mass spectrometry. InM longifolia, the major compounds were piperitenon (43.9%), tripal (14.3%), oxathiane (9.3%), piperiton oxide (5.9%), and d-limonene (4.3%). In P. gnaphalodes, the major compounds were chrysanthenyl acetate (22.38%), 2L -4L-dihydroxy eicosane (18.5%), verbenol (16.59%), dehydroaromadendrene (12.54%), β-pinen (6.43%), and 1,8 cineol (5.6%). In A. wilhelmsii, the major compounds were 1,8 cineole (13.03%), caranol (8.26%), alpha pinene (6%), farnesyl acetate (6%), and p-cymene (6%). C maculatus was more susceptible to the tested plant products than T castaneum. The oils of the three plants displayed the same insecticidal activity against C. maculatus based on LC50 values (between 1.54µl/L air in P. gnaphalodes, and 2.65 µl/L air in A. wilhelmsii). While the oils of A. wilhelmsii and M. longifolia showed the same strong insecticidal activity against T. castaneum (LC50 = 10.02 and 13.05 µl/L air, respectively), the oil of P. gnaphalodes revealed poor activity against the insect (LC50 = 297.9 µl/L air). These results suggested that essential oils from the tested plants could be used as potential control agents for stored-product insects. PMID:23413994

  19. Expression and Chloroplast Targeting of Cholesterol Oxidase in Transgenic Tobacco Plants

    PubMed Central

    Corbin, David R.; Grebenok, Robert J.; Ohnmeiss, Thomas E.; Greenplate, John T.; Purcell, John P.

    2001-01-01

    Cholesterol oxidase represents a novel type of insecticidal protein with potent activity against the cotton boll weevil (Anthonomus grandis grandis Boheman). We transformed tobacco (Nicotiana tabacum) plants with the cholesterol oxidase choM gene and expressed cytosolic and chloroplast-targeted versions of the ChoM protein. Transgenic leaf tissues expressing cholesterol oxidase exerted insecticidal activity against boll weevil larvae. Our results indicate that cholesterol oxidase can metabolize phytosterols in vivo when produced cytosolically or when targeted to chloroplasts. The transgenic plants exhibiting cytosolic expression accumulated low levels of saturated sterols known as stanols, and displayed severe developmental aberrations. In contrast, the transgenic plants expressing chloroplast-targeted cholesterol oxidase maintained a greater accumulation of stanols, and appeared phenotypically and developmentally normal. These results are discussed within the context of plant sterol distribution and metabolism. PMID:11457962

  20. Airborne multispectral detection of regrowth cotton fields

    NASA Astrophysics Data System (ADS)

    Westbrook, John K.; Suh, Charles P.-C.; Yang, Chenghai; Lan, Yubin; Eyster, Ritchie S.

    2015-01-01

    Effective methods are needed for timely areawide detection of regrowth cotton plants because boll weevils (a quarantine pest) can feed and reproduce on these plants beyond the cotton production season. Airborne multispectral images of regrowth cotton plots were acquired on several dates after three shredding (i.e., stalk destruction) dates. Linear spectral unmixing (LSU) classification was applied to high-resolution airborne multispectral images of regrowth cotton plots to estimate the minimum detectable size and subsequent growth of plants. We found that regrowth cotton fields can be identified when the mean plant width is ˜0.2 m for an image resolution of 0.1 m. LSU estimates of canopy cover of regrowth cotton plots correlated well (r2=0.81) with the ratio of mean plant width to row spacing, a surrogate measure of plant canopy cover. The height and width of regrowth plants were both well correlated (r2=0.94) with accumulated degree-days after shredding. The results will help boll weevil eradication program managers use airborne multispectral images to detect and monitor the regrowth of cotton plants after stalk destruction, and identify fields that may require further inspection and mitigation of boll weevil infestations.

  1. A Kunitz-type inhibitor of coleopteran proteases, isolated from Adenanthera pavonina L. seeds and its effect on Callosobruchus maculatus.

    PubMed

    Macedo, Maria Lígia Rodrigues; de Sá, Claudia Mara; Freire, Maria Das Graças Machado; Parra, José Roberto Postali

    2004-05-01

    The cowpea weevil Callosobruchus maculatus is one of the major pests of Vigna unguiculata cowpea. Digestion in the cowpea weevil is facilitated by high levels of cysteine and aspartic acid proteinases. Plants synthesize a variety of molecules, including proteinaceous proteinase inhibitors, to defend themselves against attack by insects. In this work, a trypsin inhibitor (ApTI) isolated from Adenanthera pavonina seeds showed activity against papain. The inhibition of papain by ApTI was of the noncompetitive type, with a K(i) of 1 microM. ApTI was highly effective against digestive proteinases from C. maculatus, Acanthoscelides obtectus (bean weevil), and Zabrotes subfasciatus (Mexican bean weevil) and was moderately active against midgut proteinases from the boll weevil Anthonomus grandis and the mealworm Tenebrio molitor. In C. maculates fed an artificial diet containing 0.25% and 0.5% ApTI (w/w), the latter concentration caused 50% mortality and reduced larval weight gain by approximately 40%. The action of ApTI on C. maculatus larvae may involve the inhibition of ApTI-sensitive cysteine proteinases and binding to chitin components of the peritrophic membrane (or equivalent structures) in the weevil midgut.

  2. Survival and behavioural responses of the predatory ladybird beetle, Eriopis connexa populations susceptible and resistant to a pyrethroid insecticide.

    PubMed

    Spíndola, A F; Silva-Torres, C S A; Rodrigues, A R S; Torres, J B

    2013-08-01

    The ladybird beetle, Eriopis connexa (Germar) (Coleoptera: Coccinellidae), is one of the commonest predators of aphids (Hemiptera: Aphididae) in the cotton agroecosystem and in many other row and fruit crops in Brazil, and has been introduced into other countries such as the USA for purposes of aphid control. In addition, the boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae) is the most serious cotton pest where it occurs, including Brazil. Controlling boll weevils and other pests such as cotton defoliators still tends to involve the intense application of insecticides to secure cotton production. The pyrethroid insecticide lambda-cyhalothrin (LCT) is commonly used, but this compound is not effective against aphids; hence, a desirable strategy would be to maintain E. connexa populations in cotton fields where LCT is applied. Using populations of E. connexa resistant (Res) and susceptible (Sus) to LCT, we compared behavioural responses on treated cotton plants and under confinement on partially and fully treated surfaces, and assessed the insects' survival on treated plants compared with that of the boll weevil. The E. connexa resistant population caged on treated plants with 15 and 75 g a.i. ha-1 exhibited ≫82% survival for both insecticide concentrations compared with ≪3% and ≪17% survival for susceptible E. connexa populations and boll weevils, respectively. The response of E. connexa Res and Sus populations when released, either on the soil or on the plant canopy, indicated avoidance towards treated plants, as measured by elapsed time to assess the plant. When compared with susceptible individuals, resistant ones took longer time to suffer insecticide knockdown, had a higher recovery rate after suffering knockdown, and spent more time in the plant canopy. Based on behavioural parameters evaluated in treated arenas, no ladybird beetles exhibited repellency. However, irritability was evident, with the susceptible population exhibiting

  3. Survival and behavioural responses of the predatory ladybird beetle, Eriopis connexa populations susceptible and resistant to a pyrethroid insecticide.

    PubMed

    Spíndola, A F; Silva-Torres, C S A; Rodrigues, A R S; Torres, J B

    2013-08-01

    The ladybird beetle, Eriopis connexa (Germar) (Coleoptera: Coccinellidae), is one of the commonest predators of aphids (Hemiptera: Aphididae) in the cotton agroecosystem and in many other row and fruit crops in Brazil, and has been introduced into other countries such as the USA for purposes of aphid control. In addition, the boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae) is the most serious cotton pest where it occurs, including Brazil. Controlling boll weevils and other pests such as cotton defoliators still tends to involve the intense application of insecticides to secure cotton production. The pyrethroid insecticide lambda-cyhalothrin (LCT) is commonly used, but this compound is not effective against aphids; hence, a desirable strategy would be to maintain E. connexa populations in cotton fields where LCT is applied. Using populations of E. connexa resistant (Res) and susceptible (Sus) to LCT, we compared behavioural responses on treated cotton plants and under confinement on partially and fully treated surfaces, and assessed the insects' survival on treated plants compared with that of the boll weevil. The E. connexa resistant population caged on treated plants with 15 and 75 g a.i. ha-1 exhibited ≫82% survival for both insecticide concentrations compared with ≪3% and ≪17% survival for susceptible E. connexa populations and boll weevils, respectively. The response of E. connexa Res and Sus populations when released, either on the soil or on the plant canopy, indicated avoidance towards treated plants, as measured by elapsed time to assess the plant. When compared with susceptible individuals, resistant ones took longer time to suffer insecticide knockdown, had a higher recovery rate after suffering knockdown, and spent more time in the plant canopy. Based on behavioural parameters evaluated in treated arenas, no ladybird beetles exhibited repellency. However, irritability was evident, with the susceptible population exhibiting

  4. The effect of insecticides on learning in the Africanized honey bee (Apis mellifera L.).

    PubMed

    Abramson, C I; Aquino, I S; Ramalho, F S; Price, J M

    1999-11-01

    The present study was designed to examine the effects of endosulfan, decis, baytroid, and sevin on the learning ability of Africanized honey bees (Apis mellifera L.). Although these insecticides were recommended by the government of Brazil to control the cotton boll weevil, the effects on bees have been unknown. Results of the present research show that: (1) bees readily consume each of the pesticides when placed in a sucrose solution; (2) the odors of the pesticides are not repellent to bees, and such odors can serve as conditioned stimuli; (3) learning occurs to various degrees when the insecticides are combined with the sucrose solution and used as an unconditioned stimulus; and (4) feeding the insecticides to the bees 1 h prior to conditioning leads to differing mortality. Because of the importance of bees for honey production, as well as pollination of cotton and other crops, recommendations are made for the use of decis and other measures for boll weevil control.http://link. springer-ny.com/link/service/journals/00244/bibs/37n4p529.++ +html

  5. First complete and productive cell culture model for members of the genus Iridovirus.

    PubMed

    D'Costa, Susan M; Vigerust, David J; Perales-Hull, Marsha R; Lodhi, Sundus A; Viravathana, Polrit; Bilimoria, Shän L

    2012-11-01

    Chilo iridescent virus (CIV; the type strain of the genus Iridovirus) replicates productively in larvae of the boll weevil, Anthonomus grandis. This study focuses on characterizing productive infections of a boll weevil cell line, BRL-AG-3A (AG3A), starting with CIV reared in the waxworm, Galleria mellonella. We show that CIV can be continually and productively passaged to high titer in AG3A cells. The replication of larval-derived CIV in AG3A was analyzed by observing viral DNA replication and restriction endonuclease digestion profiles, morphogenesis, and infectivity using TCID(50) assays with AG3A as an indicator cell line. The data showed that virus passaged in the AG3A host is stable. AG3A cells are more efficient than previously utilized CF-124T cells from Choristoneura fumiferana. This system constitutes a superior model for cellular and molecular studies on CIV; it represents the first complete, productive cell culture model for the replication of CIV or any member of the genus Iridovirus.

  6. Insect diets as mixtures: Optimization for a polyphagous weevil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development or improvement of artificial insect diets can be tedious, convoluted and under-appreciated. Modern hardware and software can be applied to efficiently sample multidimensional designs to analyze diets as n-dimensional mixtures. We identified a set of response-optimized meridic diets that ...

  7. Stability of spatial distributions of stink bugs, boll injury, and NDVI in cotton.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two-year study was conducted to determine the degree of aggregation of thrips, stink bugs, and aphids in cotton, Gossypium hirsutum L., and their spatial association with soil apparent electrical conductivity (ECa), a multispectral vegetation index (Normalized Difference Vegetation Index [NDVI]), ...

  8. Transient simulation of last deglaciation with a new mechanism for Bolling-Allerod warming.

    PubMed

    Liu, Z; Otto-Bliesner, B L; He, F; Brady, E C; Tomas, R; Clark, P U; Carlson, A E; Lynch-Stieglitz, J; Curry, W; Brook, E; Erickson, D; Jacob, R; Kutzbach, J; Cheng, J

    2009-07-17

    We conducted the first synchronously coupled atmosphere-ocean general circulation model simulation from the Last Glacial Maximum to the Bølling-Allerød (BA) warming. Our model reproduces several major features of the deglacial climate evolution, suggesting a good agreement in climate sensitivity between the model and observations. In particular, our model simulates the abrupt BA warming as a transient response of the Atlantic meridional overturning circulation (AMOC) to a sudden termination of freshwater discharge to the North Atlantic before the BA. In contrast to previous mechanisms that invoke AMOC multiple equilibrium and Southern Hemisphere climate forcing, we propose that the BA transition is caused by the superposition of climatic responses to the transient CO(2) forcing, the AMOC recovery from Heinrich Event 1, and an AMOC overshoot. PMID:19608916

  9. Edited by Bolling and WFB Emotion Awareness Predicts Body Mass Index Percentile Trajectories in Youth

    PubMed Central

    Whalen, Diana J.; Belden, Andrew C.; Barch, Deanna; Luby, Joan

    2015-01-01

    Objective To examine the rate of change in BMI percentile across three years in relation to emotion identification ability and brain-based reactivity in emotional processing regions. Study design A longitudinal sample of 202 youth completed three fMRI-based facial processing tasks and behavioral emotion differentiation tasks. We examined the rate of change in youth's BMI percentile as a function of reactivity in emotional processing brain regions and behavioral emotion identification tasks using multilevel modeling. Results Lower correct identification of both happiness and sadness measured behaviorally predicted increases in BMI percentiles across development whereas higher correct identification of both happiness and sadness predicted decreases in BMI percentiles, while controlling for children's pubertal status, gender, ethnicity, IQ score, exposure to antipsychotic medication, family income-to-needs ratio, externalizing, internalizing, and depressive symptoms. Greater neural activation in emotion reactivity regions to sad faces also predicted increases in BMI percentiles during development, also controlling for the above-mentioned covariates. Conclusions Findings provide longitudinal developmental data demonstrating a link between both emotion identification ability and greater neural reactivity in emotional processing regions with trajectories of BMI percentiles across childhood. PMID:26227437

  10. Energy efficiency assessment methods and tools evaluation. Bolling Air Force Base. Revision 1

    SciTech Connect

    McMordie, K.L.; Richman, E.E.; Keller, J.M.; Dixon, D.R.

    1995-05-01

    The goal of the U.S. Department of Energy (DOE) Federal Energy Management Program (FEMP) is to facilitate energy-efficiency improvements at federal facilities. This is accomplished by a balanced program of technology development, facility assessment, and use of cost-sharing procurement mechanisms. Technology development focuses upon the tools, software, and procedures used to identify and evaluate energy-efficiency technologies and improvements. For facility assessment, FEMP provides metering equipment and trained analysts to federal agencies exhibiting a commitment to improve energy use efficiency. To assist in procurement of energy-efficiency measures, FEMP helps federal agencies devise and implement performance contracting and utility demand-side management strategies. Pacific Northwest Laboratory (PNL) supports the FEMP mission of energy systems modernization. Under this charter, the Laboratory and its contractors work with federal facility energy managers to assess and implement energy-efficiency improvements at federal facilities nationwide.

  11. Development of a meridic diet for Hylobius transversovittatus (Coleoptera: Curculionidae) and the role of carbohydrates in feeding, growth, and survival of larvae.

    PubMed

    Tomic-Carruthers, Nada

    2007-08-01

    The root-feeding weevil Hylobius transversovittatus Goeze (Coleoptera: Curculionidae) is used for biological control of the invasive plant purple loosestrife, Luthrum salicaria L. (Lythraceae). A simple rearing system for this weevil was developed with the goals of improving production techniques and increasing the availability of insects for field introduction. Additionally, the dietary effects of digestible and indigestible carbohydrates were explored. A meridic diet for rearing H. transversovittatus was formulated through nutritional alterations of a boll weevil, Anthonomus grandis grandis Boheman, diet. Diet attractiveness was evaluated on two levels: first, by recording the incidence of initial tunneling, and second, by estimating the larval establishment rate. The performance of test diet formulations was further assessed by measuring developmental and survival rates of H. transversovittatus. Sucrose, starch, and three types of indigestible carbohydrates were tested as components to improve diet performance. Physical properties of the diet, modified by fillers in test formulations, produced major effects on the initial tunneling of hatchlings. The establishment of hatchlings was affected by chemical properties of the diet. Increases in sucrose concentration decreased larval establishment, decreased the rate of larval development, and decreased larval survival. However, omitting sucrose from the diet, or replacing it with starch, increased mortality of first instars. In advanced stages of larval development, omitting sucrose from the diet did not significantly affect larval survival. The developmental rate of larvae was increased when the amount of digestible carbohydrate was reduced. To date, seven generations of the univoltine H. transversovittatus have been successfully produced on this new meridic diet.

  12. DOE/USDA joint project to design and manufacture prototype equipment

    SciTech Connect

    Fuller, J.G.

    1996-07-01

    Design, assembly, prove-in, and performance testing of prototype equipment for the United States Department of Agriculture`s Subtropical Agriculture Research Laboratory (SARL) were completed by the Department of Energy`s Kansas City Plant. The plant is operated by AlliedSignal Federal Manufacturing & Technologies (FM&T). The prototype equipment was developed as part of the USDA`s efforts to mass produce parasitic wasps for organic control of boll weevils in cotton crops. This development was part of the Production Capability Assurance Program and also part of the Work For Others program. Design and assembly of this prototype equipment led to some new FM&T processes and technologies and exercised many others as described in the text and, at the same time, met the needs of the USDA.

  13. Potential of mass trapping for long-term pest management and eradication of invasive species.

    PubMed

    El-Sayed, A M; Suckling, D M; Wearing, C H; Byers, J A

    2006-10-01

    Semiochemical-based pest management programs comprise three major approaches that are being used to provide environmentally friendly control methods of insect pests: mass trapping, "lure and kill," and mating disruption. In this article, we review the potential of mass trapping in long-term pest management as well as in the eradication of invasive species. We discuss similarities and differences between mass trapping and other two main approaches of semiochemical-based pest management programs. We highlight several study cases where mass trapping has been used either in long-term pest management [e.g., codling moth, Cydia pomonella (L.); pink bollworm, Pectinophora gossypiella (Saunders); bark beetles, palm weevils, corn rootworms (Diabrotica spp.); and fruit flies] or in eradication of invasive species [e.g., gypsy moth, Lymantria dispar (L.); and boll weevil, Anthonomus grandis grandis Boheman). We list the critical issues that affect the efficacy of mass trapping and compare these with previously published models developed to investigate mass trapping efficacy in pest control. We conclude that mass trapping has good potential to suppress or eradicate low-density, isolated pest populations; however, its full potential in pest management has not been adequately realized and therefore encourages further research and development of this technology. PMID:17066782

  14. Genetic architecture of differences between populations of cowpea weevil (Callosobruchus maculatus) evolved in the same environment.

    PubMed

    Bieri, Jonas; Kawecki, Tadeusz J

    2003-02-01

    We investigated the genetic architecture underlying differentiation in fitness-related traits between two pairs of populations of the seed beetle Callosobruchus maculatus (Coleoptera: Bruchidae). These populations had geographically distant (> 2000 km) origins but evolved in a uniform laboratory environment for 120 generations. For each pair of populations (Nigeria x Yemen and Cameroon x Uganda) we estimated the means of five fitness-related characters and a measure of fitness (net reproductive rate R0) in each of the parental populations and 12 types of hybrids (two F1 and two F2 lines and eight backcrosses). Models containing up to nine composite genetic parameters were fitted to the means of the 14 lines. The patterns of line means for all traits in the Nigeria x Yemen cross and for four traits (larval survival, developmental rate, female body weight, and fecundity) in the Cameroon x Uganda cross were best explained by models including additive, dominance, and maternal effects, but excluding epistasis. We did not find any evidence for outbreeding depression for any trait. An epistatic component of divergence was detected for egg hatching success and R0 in the Cameroon x Uganda cross, but its sign was opposite to that expected under outbreeding depression, that is, additive x additive epistasis had a positive effect on the performance of F2 hybrids. All traits except fecundity showed a pattern of heterosis. A large difference of egg-hatching success between the two reciprocal F1 lines in that cross was best explained as fertilization incompatibility between Cameroon females and sperm carrying Uganda genes. The results suggest that these populations have not converged to the same life-history phenotype and genetic architecture, despite 120 generations of uniform natural selection. However, the absence of outbreeding depression implies that they did not evolve toward different adaptive peaks.

  15. Revision of the Australian species of the weevil genus Trigonopterus Fauvel

    PubMed Central

    Riedel, Alexander; Tänzler, Rene

    2016-01-01

    Abstract The Australian species of the genus Trigonopterus Fauvel are revised. Eight previously recognized species are redescribed and 24 additional new species are described: Trigonopterus allaetus Riedel, sp. n., Trigonopterus athertonensis Riedel, sp. n., Trigonopterus australinasutus Riedel, sp. n., Trigonopterus australis Riedel, sp. n., Trigonopterus bisignatus Riedel, sp. n., Trigonopterus bisinuatus Riedel, sp. n., Trigonopterus boolbunensis Riedel, sp. n., Trigonopterus cooktownensis Riedel, sp. n., Trigonopterus daintreensis Riedel, sp. n., Trigonopterus deplanatus Riedel, sp. n., Trigonopterus finniganensis Riedel, sp. n., Trigonopterus fraterculus Riedel, sp. n., Trigonopterus garradungensis Riedel, sp. n., Trigonopterus hasenpuschi Riedel, sp. n., Trigonopterus hartleyensis Riedel, sp. n., Trigonopterus kurandensis Riedel, sp. n., Trigonopterus lewisensis Riedel, sp. n., Trigonopterus montanus Riedel, sp. n., Trigonopterus monteithi Riedel, sp. n., Trigonopterus mossmanensis Riedel, sp. n., Trigonopterus oberprieleri Riedel, sp. n., Trigonopterus robertsi Riedel, sp. n., Trigonopterus terraereginae Riedel, sp. n., Trigonopterus yorkensis Riedel, sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel. Lectotypes are designated for the following names: Idotasia aequalis Pascoe, Idotasia albidosparsa Lea, Idotasia evanida Pascoe, Idotasia laeta Lea, Idotasia rostralis Lea, Idotasia sculptirostris Lea, Idotasia squamosa Lea. A new combination of the name Idotasia striatipennis Lea is proposed: Trigonopterus striatipennis (Lea), comb. n.. A key to the species is provided. Australian Trigonopterus occur in coastal Queensland, narrowly crossing into New South Wales. The southern parts of the range are inhabited by species found on foliage. A rich fauna of 19 edaphic species inhabiting the leaf litter of tropical forests is reported for the first time from the Australian Wet Tropics. PMID:26877696

  16. Ninety-eight new species of Trigonopterus weevils from Sundaland and the Lesser Sunda Islands

    PubMed Central

    Riedel, Alexander; Tänzler, Rene; Balke, Michael; Rahmadi, Cahyo; Suhardjono, Yayuk R.

    2014-01-01

    Abstract The genus Trigonopterus Fauvel, 1862 is highly diverse in Melanesia. Only one species, Trigonopterus amphoralis Marshall, 1925 was so far recorded West of Wallace’s Line (Eastern Sumatra). Based on focused field-work the fauna from Sundaland (Sumatra, Java, Bali, Palawan) and the Lesser Sunda Islands (Lombok, Sumbawa, Flores) is here revised. We redescribe Trigonopterus amphoralis Marshall and describe an additional 98 new species: Trigonopterus acuminatus sp. n., Trigonopterus aeneomicans sp. n., Trigonopterus alaspurwensis sp. n., Trigonopterus allopatricus sp. n., Trigonopterus allotopus sp. n., Trigonopterus angulicollis sp. n., Trigonopterus argopurensis sp. n., Trigonopterus arjunensis sp. n., Trigonopterus asper sp. n., Trigonopterus attenboroughi sp. n., Trigonopterus baliensis sp. n., Trigonopterus batukarensis sp. n., Trigonopterus bawangensis sp. n., Trigonopterus binodulus sp. n., Trigonopterus bornensis sp. n., Trigonopterus cahyoi sp. n., Trigonopterus costipennis sp. n., Trigonopterus cuprescens sp. n., Trigonopterus cupreus sp. n., Trigonopterus dacrycarpi sp. n., Trigonopterus delapan sp. n., Trigonopterus dentipes sp. n., Trigonopterus diengensis sp. n., Trigonopterus dimorphus sp. n., Trigonopterus disruptus sp. n., Trigonopterus dua sp. n., Trigonopterus duabelas sp. n., Trigonopterus echinatus sp. n., Trigonopterus empat sp. n., Trigonopterus enam sp. n., Trigonopterus fissitarsis sp. n., Trigonopterus florensis sp. n., Trigonopterus foveatus sp. n., Trigonopterus fulgidus sp. n., Trigonopterus gedensis sp. n., Trigonopterus halimunensis sp. n., Trigonopterus honjensis sp. n., Trigonopterus ijensis sp. n., Trigonopterus javensis sp. n., Trigonopterus kalimantanensis sp. n., Trigonopterus kintamanensis sp. n., Trigonopterus klatakanensis sp. n., Trigonopterus lampungensis sp. n., Trigonopterus latipes sp. n., Trigonopterus lima sp. n., Trigonopterus lombokensis sp. n., Trigonopterus merubetirensis sp. n., Trigonopterus mesehensis sp. n., Trigonopterus micans sp. n., Trigonopterus misellus sp. n., Trigonopterus palawanensis sp. n., Trigonopterus pangandaranensis sp. n., Trigonopterus paraflorensis sp. n., Trigonopterus pararugosus sp. n., Trigonopterus parasumbawensis sp. n., Trigonopterus pauxillus sp. n., Trigonopterus payungensis sp. n., Trigonopterus porcatus sp. n., Trigonopterus pseudoflorensis sp. n., Trigonopterus pseudosumbawensis sp. n., Trigonopterus punctatoseriatus sp. n., Trigonopterus ranakensis sp. n., Trigonopterus relictus sp. n., Trigonopterus rinjaniensis sp. n., Trigonopterus roensis sp. n., Trigonopterus rugosostriatus sp. n., Trigonopterus rugosus sp. n., Trigonopterus rutengensis sp. n., Trigonopterus saltator sp. n., Trigonopterus santubongensis sp. n., Trigonopterus sasak sp. n., Trigonopterus satu sp. n., Trigonopterus schulzi sp. n., Trigonopterus sebelas sp. n., Trigonopterus sembilan sp. n., Trigonopterus sepuluh sp. n., Trigonopterus seriatus sp. n., Trigonopterus serratifemur sp. n., Trigonopterus setifer sp. n., Trigonopterus silvestris sp. n., Trigonopterus singkawangensis sp. n., Trigonopterus singularis sp. n., Trigonopterus sinuatus sp. n., Trigonopterus squalidus sp. n., Trigonopterus sumatrensis sp. n., Trigonopterus sumbawensis sp. n., Trigonopterus sundaicus sp. n., Trigonopterus suturalis sp. n., Trigonopterus syarbis sp. n., Trigonopterus telagensis sp. n., Trigonopterus tepalensis sp. n., Trigonopterus tiga sp. n., Trigonopterus trigonopterus sp. n., Trigonopterus tujuh sp. n., Trigonopterus ujungkulonensis sp. n., Trigonopterus variolosus sp. n., Trigonopterus vulcanicus sp. n., Trigonopterus wallacei sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel. Most species belong to the litter fauna of primary wet evergreen forests. This habitat has become highly fragmented in the study area and many of its remnants harbor endemic species. Conservation measures should be intensified, especially in smaller and less famous sites to minimize the number of species threatened by extinction. PMID:25610340

  17. Ninety-eight new species of Trigonopterus weevils from Sundaland and the Lesser Sunda Islands.

    PubMed

    Riedel, Alexander; Tänzler, Rene; Balke, Michael; Rahmadi, Cahyo; Suhardjono, Yayuk R

    2014-01-01

    The genus Trigonopterus Fauvel, 1862 is highly diverse in Melanesia. Only one species, Trigonopterusamphoralis Marshall, 1925 was so far recorded West of Wallace's Line (Eastern Sumatra). Based on focused field-work the fauna from Sundaland (Sumatra, Java, Bali, Palawan) and the Lesser Sunda Islands (Lombok, Sumbawa, Flores) is here revised. We redescribe Trigonopterusamphoralis Marshall and describe an additional 98 new species: Trigonopterusacuminatus sp. n., Trigonopterusaeneomicans sp. n., Trigonopterusalaspurwensis sp. n., Trigonopterusallopatricus sp. n., Trigonopterusallotopus sp. n., Trigonopterusangulicollis sp. n., Trigonopterusargopurensis sp. n., Trigonopterusarjunensis sp. n., Trigonopterusasper sp. n., Trigonopterusattenboroughi sp. n., Trigonopterusbaliensis sp. n., Trigonopterusbatukarensis sp. n., Trigonopterusbawangensis sp. n., Trigonopterusbinodulus sp. n., Trigonopterusbornensis sp. n., Trigonopteruscahyoi sp. n., Trigonopteruscostipennis sp. n., Trigonopteruscuprescens sp. n., Trigonopteruscupreus sp. n., Trigonopterusdacrycarpi sp. n., Trigonopterusdelapan sp. n., Trigonopterusdentipes sp. n., Trigonopterusdiengensis sp. n., Trigonopterusdimorphus sp. n., Trigonopterusdisruptus sp. n., Trigonopterusdua sp. n., Trigonopterusduabelas sp. n., Trigonopterusechinatus sp. n., Trigonopterusempat sp. n., Trigonopterusenam sp. n., Trigonopterusfissitarsis sp. n., Trigonopterusflorensis sp. n., Trigonopterusfoveatus sp. n., Trigonopterusfulgidus sp. n., Trigonopterusgedensis sp. n., Trigonopterushalimunensis sp. n., Trigonopterushonjensis sp. n., Trigonopterusijensis sp. n., Trigonopterusjavensis sp. n., Trigonopteruskalimantanensis sp. n., Trigonopteruskintamanensis sp. n., Trigonopterusklatakanensis sp. n., Trigonopteruslampungensis sp. n., Trigonopteruslatipes sp. n., Trigonopteruslima sp. n., Trigonopteruslombokensis sp. n., Trigonopterusmerubetirensis sp. n., Trigonopterusmesehensis sp. n., Trigonopterusmicans sp. n., Trigonopterusmisellus sp. n., Trigonopteruspalawanensis sp. n., Trigonopteruspangandaranensis sp. n., Trigonopterusparaflorensis sp. n., Trigonopteruspararugosus sp. n., Trigonopterusparasumbawensis sp. n., Trigonopteruspauxillus sp. n., Trigonopteruspayungensis sp. n., Trigonopterusporcatus sp. n., Trigonopteruspseudoflorensis sp. n., Trigonopteruspseudosumbawensis sp. n., Trigonopteruspunctatoseriatus sp. n., Trigonopterusranakensis sp. n., Trigonopterusrelictus sp. n., Trigonopterusrinjaniensis sp. n., Trigonopterusroensis sp. n., Trigonopterusrugosostriatus sp. n., Trigonopterusrugosus sp. n., Trigonopterusrutengensis sp. n., Trigonopterussaltator sp. n., Trigonopterussantubongensis sp. n., Trigonopterussasak sp. n., Trigonopterussatu sp. n., Trigonopterusschulzi sp. n., Trigonopterussebelas sp. n., Trigonopterussembilan sp. n., Trigonopterussepuluh sp. n., Trigonopterusseriatus sp. n., Trigonopterusserratifemur sp. n., Trigonopterussetifer sp. n., Trigonopterussilvestris sp. n., Trigonopterussingkawangensis sp. n., Trigonopterussingularis sp. n., Trigonopterussinuatus sp. n., Trigonopterussqualidus sp. n., Trigonopterussumatrensis sp. n., Trigonopterussumbawensis sp. n., Trigonopterussundaicus sp. n., Trigonopterussuturalis sp. n., Trigonopterussyarbis sp. n., Trigonopterustelagensis sp. n., Trigonopterustepalensis sp. n., Trigonopterustiga sp. n., Trigonopterustrigonopterus sp. n., Trigonopterustujuh sp. n., Trigonopterusujungkulonensis sp. n., Trigonopterusvariolosus sp. n., Trigonopterusvulcanicus sp. n., Trigonopteruswallacei sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel. Most species belong to the litter fauna of primary wet evergreen forests. This habitat has become highly fragmented in the study area and many of its remnants harbor endemic species. Conservation measures should be intensified, especially in smaller and less famous sites to minimize the number of species threatened by extinction.

  18. Eavesdropping on coconut rhinoceros beetles, red palm weevils, Asian longhorned beetles, and other invasive travelers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As global trade increases, invasive insects inflict increasing economic damage to agriculture and urban landscapes in the United States yearly, despite a sophisticated array of interception methods and quarantine programs designed to exclude their entry. Insects that are hidden inside soil, wood, or...

  19. Transcriptomic identification of chemoreceptor genes in the red palm weevil Rhynchophorus ferrugineus.

    PubMed

    Yan, W; Liu, L; Qin, W Q; Li, C X; Peng, Z Q

    2015-01-01

    Olfaction is crucial for insects' survival because it enables them to recognize various environmental information. It is primarily mediated by a large family of chemoreceptors, including olfactory receptors (ORs), gustatory receptors (GRs), and ionotropic receptors (IRs). Here, we assembled the transcriptome of the economically important pest of palms, Rhynchophorus ferrugineus, to reveal its chemoreceptor gene repertoire. About 8.08 Gbp data were generated using a HiSeq platform and their assembly led to a total of 24,439 unigenes. Among the transcripts, 12,523 (51.24%) showed significant similarity (E-value <10(-5)) to known proteins in the National Center for Biotechnology Information Nr database. From these sequences, 18 candidate genes of ORs were identified. Nine putative transcripts were homologous to GR genes, while 9 were similar to IR genes. The expression profiles of all identified chemoreceptor genes were determined by quantitative real-time PCR in antenna, head, thorax, abdomen, and legs of both sexes. Most chemoreceptor genes were antenna-enriched. This study demonstrated a successful application of a transcriptome for discovering a large number of divergent chemoreceptor genes of a non-model organism. The findings provide a valuable sequence resource and gene tissue distribution information for systematic functional analysis of molecular mechanisms underlying chemoreception in this pest.

  20. Anoxia tolerance and anaerobic metabolism in two tropical weevil species (Coleoptera, Curculionidae).

    PubMed

    Kölsch, G

    2001-10-01

    Although the two curculionid beetle species Cosmopolites sordidus and Temnoschoita nigroplagiata are found in the same habitat (banana plantation), they differ with respect to their microhabitat preference and thereby in their risk of being submerged after rain. The physiological characteristics of the two species that might be important in this context were investigated. As expected, C. sordidus is more resistant to submergence (faster recovery, lower mortality: 30% after 9 days submergence at 20 degrees C); this can be attributed to a generally lower metabolic rate, higher glycogen reserves (135 micromol glycosyl units x g FW(-1)) and a moderate lactate production under anoxia. In T. nigroplagiata, the glycogen reserves are almost completely depleted after 1 day submergence at 20 degrees C and a higher proportion of this glycogen can recovered as lactate (16%). During submergence, the adenylate energy charge falls in both species to 0.2 or below, whereas the total adenine nucleotide content decreases only slowly, especially in C. sordidus.

  1. Transcriptomic identification of chemoreceptor genes in the red palm weevil Rhynchophorus ferrugineus.

    PubMed

    Yan, W; Liu, L; Qin, W Q; Li, C X; Peng, Z Q

    2015-01-01

    Olfaction is crucial for insects' survival because it enables them to recognize various environmental information. It is primarily mediated by a large family of chemoreceptors, including olfactory receptors (ORs), gustatory receptors (GRs), and ionotropic receptors (IRs). Here, we assembled the transcriptome of the economically important pest of palms, Rhynchophorus ferrugineus, to reveal its chemoreceptor gene repertoire. About 8.08 Gbp data were generated using a HiSeq platform and their assembly led to a total of 24,439 unigenes. Among the transcripts, 12,523 (51.24%) showed significant similarity (E-value <10(-5)) to known proteins in the National Center for Biotechnology Information Nr database. From these sequences, 18 candidate genes of ORs were identified. Nine putative transcripts were homologous to GR genes, while 9 were similar to IR genes. The expression profiles of all identified chemoreceptor genes were determined by quantitative real-time PCR in antenna, head, thorax, abdomen, and legs of both sexes. Most chemoreceptor genes were antenna-enriched. This study demonstrated a successful application of a transcriptome for discovering a large number of divergent chemoreceptor genes of a non-model organism. The findings provide a valuable sequence resource and gene tissue distribution information for systematic functional analysis of molecular mechanisms underlying chemoreception in this pest. PMID:26214426

  2. Optimal diet for production of normative adults of the Diaprepes root weevil, Diaprepes abbreviatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect diets are complex mixtures of vitamins, salts, preservatives, and nutrients (carbohydrates, lipids and proteins). To determine the effect of varying the doses of multiple components, the traditional approach requires large factorial experiments resulting in very large numbers of treatment com...

  3. One hundred and one new species of Trigonopterus weevils from New Guinea

    PubMed Central

    Riedel, Alexander; Sagata, Katayo; Surbakti, Suriani; Rene Tänzler;  Michael Balke

    2013-01-01

    Abstract A species discovery and description pipeline to accelerate and improve taxonomy is outlined, relying on concise expert descriptions, combined with DNA sequencing, digital imaging, and automated wiki species page creation from the journal. One hundred and one new species of Trigonopterus Fauvel, 1862 are described to demonstrate the feasibility of this approach: Trigonopterus aeneipennis sp. n., Trigonopterus aeneus sp. n., Trigonopterus agathis sp. n., Trigonopterus agilis sp. n., Trigonopterus amplipennis sp. n., Trigonopterus ancoruncus sp. n., Trigonopterus angulatus sp. n., Trigonopterus angustus sp. n., Trigonopterus apicalis sp. n., Trigonopterus armatus sp. n., Trigonopterus ascendens sp. n., Trigonopterus augur sp. n., Trigonopterus balimensis sp. n., Trigonopterus basalis sp. n., Trigonopterus conformis sp. n., Trigonopterus constrictus sp. n., Trigonopterus costatus sp. n., Trigonopterus costicollis sp. n., Trigonopterus crassicornis sp. n., Trigonopterus cuneipennis sp. n., Trigonopterus cyclopensis sp. n., Trigonopterus dentirostris sp. n., Trigonopterus discoidalis sp. n., Trigonopterus dromedarius sp. n., Trigonopterus durus sp. n., Trigonopterus echinus sp. n., Trigonopterus edaphus sp. n., Trigonopterus eremitus sp. n., Trigonopterus euops sp. n., Trigonopterus ferrugineus sp. n., Trigonopterus fusiformis sp. n., Trigonopterus glaber sp. n., Trigonopterus gonatoceros sp. n., Trigonopterus granum sp. n., Trigonopterus helios sp. n., Trigonopterus hitoloorum sp. n., Trigonopterus imitatus sp. n., Trigonopterus inflatus sp. n., Trigonopterus insularis sp. n., Trigonopterus irregularis sp. n., Trigonopterus ixodiformis sp. n., Trigonopterus kanawiorum sp. n., Trigonopterus katayoi sp. n., Trigonopterus koveorum sp. n., Trigonopterus kurulu sp. n., Trigonopterus lekiorum sp. n., Trigonopterus lineatus sp. n., Trigonopterus lineellus sp. n., Trigonopterus maculatus sp. n., Trigonopterus mimicus sp. n., Trigonopterus monticola sp. n., Trigonopterus montivagus sp. n., Trigonopterus moreaorum sp. n., Trigonopterus myops sp. n., Trigonopterus nangiorum sp. n., Trigonopterus nothofagorum sp. n., Trigonopterus ovatus sp. n., Trigonopterus oviformis sp. n., Trigonopterus parumsquamosus sp. n., Trigonopterus parvulus sp. n., Trigonopterus phoenix sp. n., Trigonopterus plicicollis sp. n., Trigonopterus politoides sp. n., Trigonopterus pseudogranum sp. n., Trigonopterus pseudonasutus sp. n., Trigonopterus ptolycoides sp. n., Trigonopterus punctulatus sp. n., Trigonopterus ragaorum sp. n., Trigonopterus rhinoceros sp. n., Trigonopterus rhomboidalis sp. n., Trigonopterus rubiginosus sp. n., Trigonopterus rubripennis sp. n., Trigonopterus rufibasis sp. n., Trigonopterus scabrosus sp. n., Trigonopterus scissops sp. n., Trigonopterus scharfi sp. n., Trigonopterus signicollis sp. n., Trigonopterus simulans sp. n., Trigonopterus soiorum sp. n., T sordidus sp. n., Trigonopterus squamirostris sp. n., Trigonopterus striatus sp. n., Trigonopterus strigatus sp. n., Trigonopterus strombosceroides sp. n., Trigonopterus subglabratus sp. n., Trigonopterus sulcatus sp. n., Trigonopterus taenzleri sp. n., Trigonopterus talpa sp. n., Trigonopterus taurekaorum sp. n., Trigonopterus tialeorum sp. n., Trigonopterus tibialis sp. n., Trigonopterus tridentatus sp. n., Trigonopterus uniformis sp. n., Trigonopterus variabilis sp. n., Trigonopterus velaris sp. n., Trigonopterus verrucosus sp. n., Trigonopterus violaceus sp. n., Trigonopterus viridescens sp. n., Trigonopterus wamenaensis sp. n., Trigonopterus wariorum sp. n., Trigonopterus zygops sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel. PMID:23794832

  4. Exotic weevil invasion increases floral herbivore community density, function, and impact on a native plant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumer communities are being re-arranged through unprecedented rates of human-mediated invasions and extinctions. Such changes in consumer composition and diversity potentially alter pressure and impact on resource populations. Although insect herbivore invasions are common, and exotic herbivores...

  5. Constitutively overexpressing a tomato fructokinase gene (lefrk1) in cotton (Gossypium hirsutum L. cv. coker 312) positively affects plant vegetative growth, boll number and seed cotton yield.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing fructokinase (FRK) activity in cotton (Gossypium hirsutum L.) plants may reduce fructose inhibition of sucrose synthase (Sus) and lead to improved fibre yield and quality. Cotton was transformed with a tomato (Solanum lycopersicum L.) fructokinase gene (LeFRK1) under the control of the C...

  6. Role of phermones and kairmones for insect suppression systems and their possible health and environmental impacts.

    PubMed Central

    Knipling, E F

    1976-01-01

    Insects produce pheromones as a chemical communication system to facilitate reproduction. These highly active chemical attractants have been synthesized for some of the most important insect pests, including the boll weevil, gypsy moth, codling moth, tobacco budworm, European corn borer, and several bark beetles. While none of the synthetic sex attractants have yet been developed for use in insect control, they offer opportunities for the future both as control agents and to greatly improved insect detection. Investigations are underway on insect trapping systems employing the phermones and on air permeation techniques to disrupt insect reproduction. The pheromones are generally highly species-specific and are not likely to pose hazards to nontarget organisms in the environment. Toxicological studies indicate that they are low in toxicity to mammals, birds, and fish, but adequate toxicological data are necessary before they can be registered for use in insect control. Another new class of compounds called kaironomes has been discovered. These chemicals are involved in the detection of hosts or prey by insect parasites and predators. Kairomones may prove useful in manipulating natural or released biological agents for more effective biological control of insect pests. No information is yet available on the toxicology of these chemicals. PMID:789061

  7. Diflubenzuron Hazards to Fish, Wildlife and Invertebrates: A Synoptic Review

    USGS Publications Warehouse

    Eisler, R.

    1992-01-01

    Diflubenzuron (1(4chlorophenyl)3(2,6difluorobenzoyl)urea), also known as dimilin, is a potent broad spectrum insect growth regulator that interferes with chitin synthesis at time of molting and is effective in controlling immature stages of insects. Diflubenzuron was approved for domestic use in 1976 to control gypsy moth (Lymantria dispar), and in 1979 against the cotton boll weevil (Anthonomus grandis). By 1989 this compound was also registered for domestic use against mosquitos, forest Lepidoptera, mushroom flies, and leaf-eating insect pests of citrus, woody ornamentals, vegetables, and fruit. Diflubenzuron seldom persists for more than a few days in soil and water. When used properly in forest management, it is unlikely to be leached into ground water from the application site. Degradation in water and soil is most rapid when small particle formulations are applied; microorganisms are abundant; and at elevated pH, temperature, and organic loading. Chemical and biological processes initially yield 2,6difluorobenzoic acid and 4chlorophenylurea.

  8. Evaluation of Cytotoxicity, Genotoxicity and Hematotoxicity of the Recombinant Spore-Crystal Complexes Cry1Ia, Cry10Aa and Cry1Ba6 from Bacillus thuringiensis in Swiss Mice

    PubMed Central

    de Souza Freire, Ingrid; Miranda-Vilela, Ana Luisa; Barbosa, Lilian Carla Pereira; Martins, Erica Soares; Monnerat, Rose Gomes; Grisolia, Cesar Koppe

    2014-01-01

    The insecticidal properties of Cry-endotoxins from Bacillus thuringiensis (Bt) have long been used as spore-crystals in commercial spray formulations for insect control. Recently, some Bt-endotoxin genes have been cloned in many different plants. Toxicological evaluations of three spore-crystal endotoxins, BtCry1Ia, BtCry10Aa and BtCry1Ba6 from B. thuringiensis, were carried out on mice to understand their adverse effects on hematological systems and on genetic material. These three spore-crystals have shown toxic activity to the boll weevil, which is one of the most aggressive pests of the cotton crop. Cry1Ia, Cry10Aa and Cry1Ba6 did not increase the micronucleus frequency in the peripheral erythrocytes of mice and did not cause changes in the frequency of polychromatic erythrocytes. However, some hematologic disburbances were observed, specifically related to Cry1Ia and Cry1Ba6, respectively, for the erythroid and lymphoid lineage. Thus, although the profile of such adverse side effects can be related to their high level of exposure, which is not commonly found in the environment, results showed that these Bt spore-crystals were not harmless to mice, indicating that each spore-crystal endotoxin presents a characteristic profile of toxicity and might be investigated individually. PMID:25268978

  9. Chemical composition and biological activity of star anise Illicium verum extracts against maize weevil, Sitophilus zeamais adults.

    PubMed

    Wei, Linlin; Hua, Rimao; Li, Maoye; Huang, Yanzhang; Li, Shiguang; He, Yujie; Shen, Zonghai

    2014-01-01

    This study aims to develop eco-friendly botanical pesticides. Dried fruits of star anise (Illicium verum Hook.f. (Austrobaileyales: Schisandraceae)) were extracted with methyl alcohol (MA), ethyl acetate (EA), and petroleum ether (PE) at 25°C. The constituents were determined by gas chromatography-mass spectrometry, and the repellency and contact toxicity of the extracts against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) adults were tested. Forty-four compounds, whose concentrations were more than 0.2%, were separated and identified from the MA, EA, and PE extracts. The extraction yields of trans-anethole, the most abundant biologically active compound in I. verum, were 9.7%, 7.5%, and 10.1% in the MA, EA, and PE extracts, respectively. Repellency increased with increasing extract dose. The average repellency rate of the extracts against S. zeamais adults peaked at 125.79 µg/cm(2) 72 hr after treatment. The percentage repellency of the EA extract reached 76.9%, making it a class IV repellent. Contact toxicity assays showed average mortalities of 85.4% (MA), 94.5% (EA), and 91.1% (PE). The EA extract had the lowest median lethal dose, at 21.2 µg/cm(2) 72 hr after treatment. The results suggest that I. verum fruit extracts and trans-anethole can potentially be developed as a grain protectant to control stored-product insect pests. Other active constituents in the EA extract merit further research. PMID:25368036

  10. Albizia lebbeck Seed Coat Proteins Bind to Chitin and Act as a Defense against Cowpea Weevil Callosobruchus maculatus.

    PubMed

    Silva, Nadia C M; De Sá, Leonardo F R; Oliveira, Eduardo A G; Costa, Monique N; Ferreira, Andre T S; Perales, Jonas; Fernandes, Kátia V S; Xavier-Filho, Jose; Oliveira, Antonia E A

    2016-05-11

    The seed coat is an external tissue that participates in defense against insects. In some nonhost seeds, including Albizia lebbeck, the insect Callosobruchus maculatus dies during seed coat penetration. We investigated the toxicity of A. lebbeck seed coat proteins to C. maculatus. A chitin-binding protein fraction was isolated from seed coat, and mass spectrometry showed similarity to a C1 cysteine protease. By ELM program an N-glycosylation interaction motif was identified in this protein, and by molecular docking the potential to interact with N-acetylglucosamine (NAG) was shown. The chitin-binding protein fraction was toxic to C. maculatus and was present in larval midgut and feces but not able to hydrolyze larval gut proteins. It did not interfere, though, with the intestinal cell permeability. These results indicate that the toxicity mechanism of this seed coat fraction may be related to its binding to chitin, present in the larvae gut, disturbing nutrient absorption. PMID:27078512

  11. Susceptibility of the Filbertworm (Cydia latiferreana, Lepidoptera: Tortricidae) And Filbert Weevil (Curculio occidentalis, Coleoptera: Curculionidae) to Entomopathogenic Nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hazelnut (Corylus avellana L.) is an important nut crop produced around the world including the United States. Oregon’s Willamette Valley accounts for about 99% of hazelnuts grown in the United States. The objective of this study was to determine the susceptibility of the two primary direct insect...

  12. Development and characterization of 11 microsatellite markers in the root-gall-forming weevil, Ceutorhynchus assimilis (Coleoptera: Curculionidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The host race of Ceutorhynchus assimilis (Coleoptera: Curculionidae) that specifically develops on Lepidium draba (Brassicales: Brassicaceae), an invasive weed in North America, is being considered for use as a biocontrol agent. Because there are other races that attack other plants, it is important...

  13. Emerging insect problems in peach: A new look at root-feeding weevils and the lesser peachtree borer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although the fruit-attacking plum curculio remains the primary pest of peach production across the Southeastern Unites States, other insect pests that attack the peach tree can inflict serious economic losses. Some of these other pests, such as scale insects and the peachtree borer, are common pest...

  14. Electrophysiological and behavioral activity of (E)-2-hexenal in the granary weevil and its application in food packaging.

    PubMed

    Germinara, G S; Conte, A; De Cristofaro, A; Lecce, L; Di Palma, A; Rotundo, G; Del Nobile, M A

    2012-02-01

    The purpose of this work was to develop a biodegradable carrier material to control insect pests in cereal products. To this aim, (E)-2-hexenal was used, being a natural compound with antimicrobial activity that is also commonly adopted as a flavoring agent. Three coating layers of polycaprolactone (PCL) were spread onto the internal side of a paperboard carton, the first being the active coating containing (E)-2-hexenal. The antennal sensitivity of Sitophilus granarius to a broad range of doses of (E)-2-hexenal was first demonstrated. Next, the ability of different concentrations of this compound to disrupt the orientation of adult S. granarius beetles to odors of intact wheat kernels was established in a two-choice pitfall bioassay. In addition, invasion tests were carried out over an 8-week period to highlight the effects of the biobased repellent packaging and their potential persistence. The results demonstrated that during the entire monitoring period, the percentage of S. granarius adults found in cartons coated with (E)-2-hexenal-loaded multilayer PCL was about 10 % of the total number of insects used in the bioassay, very low compared with the respective control samples, thus assessing both the effectiveness and persistence of the repellent system developed. Although the infestation level of treated packages was reduced relative to the infestation levels in the controls, any infestation of food packages is unacceptable to consumers, so further tests are required to determine whether infestation can be completely prevented using (E)-2-hexenal.

  15. Mile-a-minute weed (Persicaria perfoliata) and weevil (Rhinoncomimus latipes) response to varying moisture and temperature conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The combined effects of herbivory and water stress on growth and reproduction of mile-a-minute weed (Persicaria perfoliata (L.) H. Gross) were investigated in greenhouse trials over two years, with well-watered or water-limited plants either exposed or not exposed to herbivory by the mile-a-minute w...

  16. A survey of the weevils of Ukraine. Bark and ambrosia beetles (Coleoptera: Curculionidae: Platypodinae and Scolytinae).

    PubMed

    Nikulina, Tatyana; Mandelshtam, Mikhail; Petrov, Alexander; Nazarenko, Vitalij; Yunakov, Nikolai

    2015-01-22

    Our knowledge of Ukrainian bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) is summarized as a baseline for future studies of the fauna, with a checklist including information on distribution, host trees, biology and taxonomy. One hundred twenty-two species are recorded from Ukraine, of which seven are recorded for the first time. One species is recorded for the first time from Europe. Previous records of 24 species are considered dubious and requiring confirmation. In contrast to the Palaearctic Catalogue (Knížek 2011b), we consider Anisandrus maiche to be first described by Kurentsov (1941) rather than by Eggers (1942); A. maiche (Eggers, 1942) is a junior synonym of A. maiche (Kurentsov, 1941). 

  17. Albizia lebbeck Seed Coat Proteins Bind to Chitin and Act as a Defense against Cowpea Weevil Callosobruchus maculatus.

    PubMed

    Silva, Nadia C M; De Sá, Leonardo F R; Oliveira, Eduardo A G; Costa, Monique N; Ferreira, Andre T S; Perales, Jonas; Fernandes, Kátia V S; Xavier-Filho, Jose; Oliveira, Antonia E A

    2016-05-11

    The seed coat is an external tissue that participates in defense against insects. In some nonhost seeds, including Albizia lebbeck, the insect Callosobruchus maculatus dies during seed coat penetration. We investigated the toxicity of A. lebbeck seed coat proteins to C. maculatus. A chitin-binding protein fraction was isolated from seed coat, and mass spectrometry showed similarity to a C1 cysteine protease. By ELM program an N-glycosylation interaction motif was identified in this protein, and by molecular docking the potential to interact with N-acetylglucosamine (NAG) was shown. The chitin-binding protein fraction was toxic to C. maculatus and was present in larval midgut and feces but not able to hydrolyze larval gut proteins. It did not interfere, though, with the intestinal cell permeability. These results indicate that the toxicity mechanism of this seed coat fraction may be related to its binding to chitin, present in the larvae gut, disturbing nutrient absorption.

  18. Weathering rate of male rubber septa impregnator sex pheromone of Sweetpotato Weevil, Cylas formicarius elegantulus (Coleoptera: Brentidae), in East Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, sweet potato, Ipomoea batatas (L.) Lamarck, production in Hawaii has been increasing, reaching 190 harvested ha, with a total production of 3.78 million kg in 2009. Sweet potato production in Hawaii is hindered by three major quarantine pests, for which only one, the sweetpotato we...

  19. Genetic and behavioral differences among purported species of the weevil Trichosirocalus (Coleoptera: Curculionidae) for biological control of thistles (Asteraceae, Cardueae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract and Interpretive Summary: Provide electronically in Word. Trichosirocalus horridus was introduced to North America, New Zealand and Australia for biological control of Carduus nutans. Since then two more species of Trichosirocalus have been described (Alonso-Zarazaga and Sánchez-...

  20. Respiratory metabolic responsiveness during the pupal stage of the red palm weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae) to certain plant extracts.

    PubMed

    Bream, A S; Ghoneim, K S; Tanani, M A; Nassar, M I

    2001-01-01

    The prepupae of Rhynchophorus ferrugineous were topically applied with one of three dose-levels (0.1, 0.005 or 0.001 microgram/insect) of Jojoba oil (Joj) or azadirachtin (Azt). The daily O2 consumption and CO2 respiratory output were determined and the respiratory quotient (RQ) was calculated. After Joj treatments, O2 consumption of early- and late pupae increased as the dose-level was decreased. The respiration curve did not assume an U-shaped pattern as common in the pupal stage of many insect species. Also, an inhibitory action of Azt on the pupal respiration has been clearly exhibited. A similar result of the respiration curve was observed by Azt. All dose levels of Joj, but only the higher two ones of Azt, suppressed the CO2 release. Both botanicals inhibited the RQ during the pupal stage. However, all RQ mean values of treated or control pupae were < 1.0 and > 0.7.

  1. Effects of gamma radiation on the sweet potato weevil, Cylas formicarius elegantulus (Summers). Progress report, June 1984-August 1984

    SciTech Connect

    Dawes, M.A.

    1984-01-01

    The following tests are reported: with eggs, with larvae in sweet potato roots, with larvae in sweet potato slices, with pupae in sweet potato roots, with adults, and sterility studies. Data are presented. (MHR)

  2. Chemical Composition and Biological Activity of Star Anise Illicium verum Extracts Against Maize Weevil, Sitophilus zeamais Adults

    PubMed Central

    Wei, Linlin; Hua, Rimao; Li, Maoye; Huang, Yanzhang; Li, Shiguang; He, Yujie; Shen, Zonghai

    2014-01-01

    This study aims to develop eco-friendly botanical pesticides. Dried fruits of star anise (Illicium verum Hook.f. (Austrobaileyales: Schisandraceae)) were extracted with methyl alcohol (MA), ethyl acetate (EA), and petroleum ether (PE) at 25°C. The constituents were determined by gas chromatography-mass spectrometry, and the repellency and contact toxicity of the extracts against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) adults were tested. Fortyfour compounds, whose concentrations were more than 0.2%, were separated and identified from the MA, EA, and PE extracts. The extraction yields of trans-anethole, the most abundant biologically active compound in I. verum, were 9.7%, 7.5%, and 10.1% in the MA, EA, and PE extracts, respectively. Repellency increased with increasing extract dose. The average repellency rate of the extracts against S. zeamais adults peaked at 125.79 μg/cm2 72 hr after treatment. The percentage repellency of the EA extract reached 76.9%, making it a class IV repellent. Contact toxicity assays showed average mortalities of 85.4% (MA), 94.5% (EA), and 91.1% (PE). The EA extract had the lowest median lethal dose, at 21.2 μg/cm2 72 hr after treatment. The results suggest that I. verum fruit extracts and trans-anethole can potentially be developed as a grain protectant to control stored-product insect pests. Other active constituents in the EA extract merit further research. PMID:25368036

  3. Increased seed consumption by biological control weevil tempers positive CO2 effect on invasive plant (Centaurea diffusa) fitness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predicted increases in atmospheric CO2 and temperature may benefit some invasive plants, increasing the need for effective invasive plant management. Biological control can be an effective means of managing invasive plants, but the varied responses of plant-insect interactions to climate change make...

  4. Food safety knowledge on the Bt mutant protein Cry8Ka5 employed in the development of coleopteran-resistant transgenic cotton plants.

    PubMed

    Farias, Davi F; Peijnenburg, Ad A C M; Grossi-de-Sá, Maria F; Carvalho, Ana F U

    2015-01-01

    Insecticidal Cry proteins from Bacillus thuringiensis (Bt) have been exploited in the development of genetically modified (GM) crops for pest control. However, several pests are still difficult to control such as the coleopteran boll weevil Anthonomus grandis. By applying in vitro molecular evolution to the cry8Ka1 gene sequence, variants were generated with improved activity against A. grandis. Among them, Cry8Ka5 mutant protein showed coleoptericidal activity 3-fold higher (LC50 2.83 μg/mL) than that of the original protein (Cry8Ka1). Cry8Ka5 has been used in breeding programs in order to obtain coleopteran-resistant cotton plants. Nevertheless, there is some concern in relation to the food safety of transgenic crops, especially to the heterologously expressed proteins. In this context, our research group has performed risk assessment studies on Cry8Ka5, using the tests recommended by Codex as well as tests that we proposed as alternative and/or complementary approaches. Our results on the risk analysis of Cry8Ka5 taken together with those of other Cry proteins, point out that there is a high degree of certainty on their food safety. It is reasonable to emphasize that most safety studies on Cry proteins have essentially used the Codex approach. However, other methodologies would potentially provide additional information such as studies on the effects of Cry proteins and derived peptides on the indigenous gastrointestinal microbiota and on intestinal epithelial cells of humans. Additionally, emerging technologies such as toxicogenomics potentially will offer sensitive alternatives for some current approaches or methods. PMID:26513483

  5. Optimal Cotton Insecticide Application Termination Timing: A Meta-Analysis.

    PubMed

    Griffin, T W; Zapata, S D

    2016-08-01

    The concept of insecticide termination timing is generally accepted among cotton (Gossypium hirsutum) researchers; however, exact timings are often disputed. Specifically, there is uncertainty regarding the last economic insecticide application to control fruit-feeding pests including tarnished plant bug (Lygus lineolaris (Palisot de Beauvois)), boll weevil (Anthonomus grandis), bollworm (Helicoverpa zea), tobacco budworm (Heliothis virescens), and cotton fleahopper (Pseudatomoscelis seriatus). A systematic review of prior studies was conducted within a meta-analytic framework. Nine publicly available articles were amalgamated to develop an optimal timing principle. These prior studies reported 53 independent multiple means comparison field experiments for a total of 247 trial observations. Stochastic plateau theory integrated with econometric meta-analysis methodology was applied to the meta-database to determine the shape of the functional form of both the agronomic optimal insecticide termination timing and corresponding yield potential. Results indicated that current university insecticide termination timing recommendations are later than overall estimated timing suggested. The estimated 159 heat units (HU) after the fifth position above white flower (NAWF5) was found to be statistically different than the 194 HU termination used as the status quo recommended termination timing. Insecticides applied after 159 HU may have been applied in excess, resulting in unnecessary economic and environmental costs. Empirical results also suggested that extending the insecticide termination time by one unit resulted in a cotton lint yield increase of 0.27 kilograms per hectare up to the timing where the plateau began. Based on economic analyses, profit-maximizing producers may cease application as soon as 124 HU after NAWF5. These results provided insights useful to improve production systems by applying inputs only when benefits were expected to be in excess of the

  6. Food safety knowledge on the Bt mutant protein Cry8Ka5 employed in the development of coleopteran-resistant transgenic cotton plants.

    PubMed

    Farias, Davi F; Peijnenburg, Ad A C M; Grossi-de-Sá, Maria F; Carvalho, Ana F U

    2015-01-01

    Insecticidal Cry proteins from Bacillus thuringiensis (Bt) have been exploited in the development of genetically modified (GM) crops for pest control. However, several pests are still difficult to control such as the coleopteran boll weevil Anthonomus grandis. By applying in vitro molecular evolution to the cry8Ka1 gene sequence, variants were generated with improved activity against A. grandis. Among them, Cry8Ka5 mutant protein showed coleoptericidal activity 3-fold higher (LC50 2.83 μg/mL) than that of the original protein (Cry8Ka1). Cry8Ka5 has been used in breeding programs in order to obtain coleopteran-resistant cotton plants. Nevertheless, there is some concern in relation to the food safety of transgenic crops, especially to the heterologously expressed proteins. In this context, our research group has performed risk assessment studies on Cry8Ka5, using the tests recommended by Codex as well as tests that we proposed as alternative and/or complementary approaches. Our results on the risk analysis of Cry8Ka5 taken together with those of other Cry proteins, point out that there is a high degree of certainty on their food safety. It is reasonable to emphasize that most safety studies on Cry proteins have essentially used the Codex approach. However, other methodologies would potentially provide additional information such as studies on the effects of Cry proteins and derived peptides on the indigenous gastrointestinal microbiota and on intestinal epithelial cells of humans. Additionally, emerging technologies such as toxicogenomics potentially will offer sensitive alternatives for some current approaches or methods.

  7. Optimal Cotton Insecticide Application Termination Timing: A Meta-Analysis.

    PubMed

    Griffin, T W; Zapata, S D

    2016-08-01

    The concept of insecticide termination timing is generally accepted among cotton (Gossypium hirsutum) researchers; however, exact timings are often disputed. Specifically, there is uncertainty regarding the last economic insecticide application to control fruit-feeding pests including tarnished plant bug (Lygus lineolaris (Palisot de Beauvois)), boll weevil (Anthonomus grandis), bollworm (Helicoverpa zea), tobacco budworm (Heliothis virescens), and cotton fleahopper (Pseudatomoscelis seriatus). A systematic review of prior studies was conducted within a meta-analytic framework. Nine publicly available articles were amalgamated to develop an optimal timing principle. These prior studies reported 53 independent multiple means comparison field experiments for a total of 247 trial observations. Stochastic plateau theory integrated with econometric meta-analysis methodology was applied to the meta-database to determine the shape of the functional form of both the agronomic optimal insecticide termination timing and corresponding yield potential. Results indicated that current university insecticide termination timing recommendations are later than overall estimated timing suggested. The estimated 159 heat units (HU) after the fifth position above white flower (NAWF5) was found to be statistically different than the 194 HU termination used as the status quo recommended termination timing. Insecticides applied after 159 HU may have been applied in excess, resulting in unnecessary economic and environmental costs. Empirical results also suggested that extending the insecticide termination time by one unit resulted in a cotton lint yield increase of 0.27 kilograms per hectare up to the timing where the plateau began. Based on economic analyses, profit-maximizing producers may cease application as soon as 124 HU after NAWF5. These results provided insights useful to improve production systems by applying inputs only when benefits were expected to be in excess of the

  8. Non-constant thermal regimes enhance overwintering success and accelerate diapause development for Smicronyx fulvus (Coleoptera: Curculionidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent populations of the red sunflower seed weevil, Smicronyx fulvus LeConte (Coleoptera: Curculionidae) have been inconsistent or declining, particularly in North Dakota. Consequently, field and laboratory research on weevil biology, including development of resistant germplasm, have been limited....

  9. Digestion of starch granules from maize, potato and wheat by larvae of the the yellow mealworm, Tenebrio molitor and the Mexican bean weevil, Zabrotes subfasciatus.

    PubMed

    Meireles, Elaine A; Carneiro, Cíntia N B; DaMatta, Renato A; Samuels, Richard I; Silva, Carlos P

    2009-01-01

    Scanning electron microscopy images were taken of starch granules from different sources following exposure in vivo and in vitro to gut alpha-amylases isolated from Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae). One alpha-amylase was isolated from whole larval midguts of T. molitor using non-denaturing SDS-PAGE, while two other alpha-amylase fractions were isolated from whole larval midguts of Z. subfasciatus using hydrophobic interaction chromatography., Digested starch granules from larvae fed on maize, potato or wheat were isolated from midgut contents. Combinations of starch granules with isolated alpha-amylases from both species showed similar patterns of granule degradation. In vitro enzymatic degradation of maize starch granules by the three different alpha-amylase fractions began by creating small holes and crater-like areas on the surface of the granules. Over time, these holes increased in number and area resulting in extensive degradation of the granule structure. Granules from potato did not show formation of pits and craters on their surface, but presented extensive erosion in their interior. For all types of starch, as soon as the interior of the starch granule was reached, the inner layers of amylose and amylopectin were differentially hydrolyzed, resulting in a striated pattern. These data support the hypothesis that the pattern of starch degradation depends more on the granule type than on the alpha-amylase involved. PMID:19619014

  10. The response of phosphine-resistant lesser grain borer Rhyzopertha dominica and rice weevil Sitophilus oryzae in mixed-age cultures to varying concentrations of phosphine.

    PubMed

    Rajendran, Somiahnadar; Gunasekaran, Nagamuthu

    2002-03-01

    The response of Rhyzopertha dominica and Sitophilus oryzae (both phosphine-resistant) in mixed-age cultures to phosphine at fixed concentration-time products (CT) of 10,500 to 168,000 microliters litre 1 h (ppm h) with either constant, rising or falling concentrations for 7 days was studied at 27 (+/- 2) degrees C. At lower CT products, rising concentrations of phosphine led to significantly fewer survivors of R dominica and S oryzae. Conversely, exposure to falling concentrations of phosphine resulted in significantly more survivors. The influence of changing concentrations of phosphine was more pronounced in S oryzae than in R dominica. In the latter, at the lower CT products of 21,000 and 42,000 microliters-1 h, the adult stage proved to be most tolerant, contrary to the accepted belief that the egg or pupal stage are always more tolerant to phosphine. The results indicate that application of phosphine in rising concentrations is more effective than in constant or falling concentrations.

  11. Identification and electrophysiological studies of (4 S,5 S)-5-hydroxy-4-methyl-3-heptanone and 4-methyl-3,5-heptanedione in male lucerne weevils

    NASA Astrophysics Data System (ADS)

    Unelius, C. R.; Park, K.-C.; McNeill, M.; Wee, S. L.; Bohman, B.; Suckling, D. M.

    2013-02-01

    An investigation to identify a sex or aggregation pheromone of Sitona discoideus Gyllenhål (Coleoptera: Curculionidae) is presented. Antenna flicking and attraction behaviors evoked by conspecifics of both sexes were recorded in arena bioassays, where attraction of females to males was observed. Air entrainment of both males and females was conducted in separate chambers. Gas chromatographic-mass spectrometric analysis of headspace volatiles revealed that two male-specific compounds, 4-methyl-3,5-heptanedione (major) and (4 S,5 S)-5-hydroxy-4-methyl-3-heptanone (minor), were emitted during the autumnal post-aestivatory flight period. The stereoisomers of the minor component were separated by enantioselective gas chromatography and their absolute configurations assigned by NMR (diastereomers) and the known preference of enantioselective transesterification reactions catalyzed by Candida antarctica lipase B. Electroantennogram and single sensillum recording studies indicate that 4-methyl-3,5-heptanedione as well as all individual stereoisomers of 5-hydroxy-4-methyl-3-heptanone are detected by the antennae of male and female S. discoideus. Further, single sensillum recordings suggest that both sexes of S. discoideus have specialized olfactory receptor neurons (ORNs) for detecting 4-methyl-3,5-heptanedione and different populations of stereoselective ORNs for detecting the stereoisomers of 5-hydroxy-4-methyl-3-heptanone. Some of these stereoselective ORNs appear to be sex-specific in S. discoideus.

  12. Taxonomic redescription and biological notes on Diaugia angusta (Diptera, Tachinidae): parasitoid of the palm boring weevils Metamasius ensirostris and M. hemipterus (Coleoptera, Dryophthoridae)

    PubMed Central

    Nihei, Silvio Shigueo; Pavarini, Ronaldo

    2011-01-01

    Abstract Diaugia angusta Perty, 1833 is a Neotropical species of Tachinidae (Diptera) reported here as a parasitoid of Metamasius ensirostris (Germar, 1824) and Metamasius hemipterus (Linnaeus, 1758) (Coleoptera: Dryophthoridae) in Brazil. Several species of Dryophthoridae and Curculionidae cause damage to bromeliad and palm species, and most are regarded as pests. In the present study, the male and female of Diaugia angusta are morphologically characterized and illustrated to provide a means for the identification of this parasitoid. Data obtained from preliminary field research show that natural parasitism of Metamasius pupae by Diaugia angusta varies by year but can reach nearly 30%. A network of parasitoid-host interactions among tachinid parasitoids and coleopteran hosts reported as bromeliad and palm pests (Dryophthoridae and Curculionidae) in the Americas indicates that the species of the tribe Dexiini sensu lato (including Diaugia angusta) might be promising as biological control agents of these pests. PMID:21594164

  13. The description of a new calyptrate fly mimicking species of the fungus weevil genus Gymnognathus Schönherr 1826 from the southern Bolivian Andes (Coleoptera: Anthribidae: Anthribinae).

    PubMed

    Perger, Robert; Guerra, Fernando

    2016-01-01

    A new calyptrate fly mimicking species of Gymnognathus Schönherr 1826 from the humid Tucuman-Bolivian forest in the southern Bolivian Andes is described. Gymnognathus barclayi sp. nov. is distinguished from the closest related species G. bohlsi Jordan, 1895, by the color and/or distribution of the scales on the pronotum, fourth ventrite and pygidium, the wider pronotum and the development of the spines on the pygidium. The arrangement of the longitudinal stripes on the pronotum suggests that G. barclayi sp. nov. is a mimic of tachinid or muscid flies. The almost exclusive occurrence of Gymnognathus species in tropical moist forests indicates that the presence of G. barclayi sp. nov. in the subtropical realm is fostered by increased humidity at orographic rain barriers. G. barclayi sp. nov. is possibly endemic to the Tucuman-Bolivian forest. Along with the presence of other endemic species, the discovery of G. barclayi sp. nov. highlights the importance of the Tucuman-Bolivian forest as an endemism hotspot for insects and calls for a re-assessment of the conservation status of this spatially restricted and threatened ecoregion. PMID:27394264

  14. Assessing climate change impacts on the rape stem weevil, Ceutorhynchus napi Gyll., based on bias- and non-bias-corrected regional climate change projections.

    PubMed

    Junk, J; Ulber, B; Vidal, S; Eickermann, M

    2015-11-01

    Agricultural production is directly affected by projected increases in air temperature and changes in precipitation. A multi-model ensemble of regional climate change projections indicated shifts towards higher air temperatures and changing precipitation patterns during the summer and winter seasons up to the year 2100 for the region of Goettingen (Lower Saxony, Germany). A second major controlling factor of the agricultural production is the infestation level by pests. Based on long-term field surveys and meteorological observations, a calibration of an existing model describing the migration of the pest insect Ceutorhynchus napi was possible. To assess the impacts of climate on pests under projected changing environmental conditions, we combined the results of regional climate models with the phenological model to describe the crop invasion of this species. In order to reduce systematic differences between the output of the regional climate models and observational data sets, two different bias correction methods were applied: a linear correction for air temperature and a quantile mapping approach for precipitation. Only the results derived from the bias-corrected output of the regional climate models showed satisfying results. An earlier onset, as well as a prolongation of the possible time window for the immigration of Ceutorhynchus napi, was projected by the majority of the ensemble members.

  15. Expression, purification, crystallization and preliminary X-ray diffraction analysis of the pectin methylesterase from the sugar cane weevil Sphenophorus levis

    PubMed Central

    Evangelista, Danilo Elton; Schutzer de Godoy, Andre; Fonseca Pereira de Paula, Fernando; Henrique-Silva, Flavio; Polikarpov, Igor

    2014-01-01

    Pectin methylesterase removes the methyl groups from the main chain of pectin, the major component of the middle lamella of the plant cell wall. The enzyme is involved in plant cell-wall development, is part of the enzymatic arsenal used by microorganisms to attack plants and also has a wide range of applications in the industrial sector. Therefore, there is a considerable interest in studies of the structure and function of this enzyme. In this work, the pectin methylesterase from Sphenophorus levis was produced in Pichia pastoris and purified. Crystals belonging to the monoclinic space group C2, with unit-cell parameters a = 122.181, b = 82.213, c = 41.176 Å, β = 97.48°, were obtained by the sitting-drop vapour-diffusion method and an X-ray diffraction data set was collected to 2.1 Å resolution. Structure refinement and model building are in progress. PMID:24598920

  16. Assessing climate change impacts on the rape stem weevil, Ceutorhynchus napi Gyll., based on bias- and non-bias-corrected regional climate change projections

    NASA Astrophysics Data System (ADS)

    Junk, J.; Ulber, B.; Vidal, S.; Eickermann, M.

    2015-11-01

    Agricultural production is directly affected by projected increases in air temperature and changes in precipitation. A multi-model ensemble of regional climate change projections indicated shifts towards higher air temperatures and changing precipitation patterns during the summer and winter seasons up to the year 2100 for the region of Goettingen (Lower Saxony, Germany). A second major controlling factor of the agricultural production is the infestation level by pests. Based on long-term field surveys and meteorological observations, a calibration of an existing model describing the migration of the pest insect Ceutorhynchus napi was possible. To assess the impacts of climate on pests under projected changing environmental conditions, we combined the results of regional climate models with the phenological model to describe the crop invasion of this species. In order to reduce systematic differences between the output of the regional climate models and observational data sets, two different bias correction methods were applied: a linear correction for air temperature and a quantile mapping approach for precipitation. Only the results derived from the bias-corrected output of the regional climate models showed satisfying results. An earlier onset, as well as a prolongation of the possible time window for the immigration of Ceutorhynchus napi, was projected by the majority of the ensemble members.

  17. Bottom-up effects on top-down regulation of a floating aquatic plant by two weevil species: the context-specific nature of biological control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Plant nutrition (bottom-up effects) impacts a plant’s ability to sustain herbivory (top-down effects) and affects phytophagous insect fecundity. These factors potentially confound efficacy predictions for biological control projects. We investigated the relative importance of these two forces wi...

  18. Digestion of starch granules from maize, potato and wheat by larvae of the the yellow mealworm, Tenebrio molitor and the Mexican bean weevil, Zabrotes subfasciatus.

    PubMed

    Meireles, Elaine A; Carneiro, Cíntia N B; DaMatta, Renato A; Samuels, Richard I; Silva, Carlos P

    2009-01-01

    Scanning electron microscopy images were taken of starch granules from different sources following exposure in vivo and in vitro to gut alpha-amylases isolated from Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae). One alpha-amylase was isolated from whole larval midguts of T. molitor using non-denaturing SDS-PAGE, while two other alpha-amylase fractions were isolated from whole larval midguts of Z. subfasciatus using hydrophobic interaction chromatography., Digested starch granules from larvae fed on maize, potato or wheat were isolated from midgut contents. Combinations of starch granules with isolated alpha-amylases from both species showed similar patterns of granule degradation. In vitro enzymatic degradation of maize starch granules by the three different alpha-amylase fractions began by creating small holes and crater-like areas on the surface of the granules. Over time, these holes increased in number and area resulting in extensive degradation of the granule structure. Granules from potato did not show formation of pits and craters on their surface, but presented extensive erosion in their interior. For all types of starch, as soon as the interior of the starch granule was reached, the inner layers of amylose and amylopectin were differentially hydrolyzed, resulting in a striated pattern. These data support the hypothesis that the pattern of starch degradation depends more on the granule type than on the alpha-amylase involved.

  19. A PCR-Based Diagnostic System for Differentiating Two Weevil Species (Coleoptera: Curculionidae) of Economic Importance to the Chilean Citrus Industry.

    PubMed

    Aguirre, C; Olivares, N; Luppichini, P; Hinrichsen, P

    2015-02-01

    A PCR-based method was developed to identify Naupactus cervinus (Boheman) and Naupactus xanthographus (Germar), two curculionids affecting the citrus industry in Chile. The quarantine status of these two species depends on the country to which fruits are exported. This identification method was developed because it is not possible to discriminate between these two species at the egg stage. The method is based on the species-specific amplification of sequences of internal transcribed spacers, for which we cloned and sequenced these genome fragments from each species. We designed an identification system based on two duplex-PCR reactions. Each one contains the species-specific primer set and a second generic primer set that amplify a short 18S region common to coleopterans, to avoid false negatives. The marker system is able to differentiate each Naupactus species at any life stage, and with a diagnostic sensitivity to 0.045 ng of genomic DNA. This PCR kit was validated by samples collected from different citrus production areas throughout Chile and showed 100% accuracy in differentiating the two Naupactus species. PMID:26470110

  20. Transmission and Importance of Pantoea ananatis During Feeding on Cotton Buds (Gossypium hirsutum L.) by Cotton Fleahoppers (Pseudatomoscelis seriatus Reuter)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fleahoppers collected from various hosts in the field or raised on green beans in the laboratory were frequently infested with Pantoea spp. These isolates caused a severe internal boll rot in cotton when introduced into young bolls via a small puncture wound caused by a 28-gauge needle. Bud...

  1. Oviposition Patterns of Creontiades signatus (Hemiptera: Miridae) on Okra-Leaf and Normal-Leaf Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report the boll injury and oviposition site preference of Creontiades signatus (Distant), a relatively new plant bug pest of cotton in the United States. We compared a technique of injecting bolls with pectinase to enclosing a 5th instar, C. signatus nymph, to investigate the techniques potential...

  2. Relationship Between Piercing-Sucking Insect Control and Internal Lint and Seed Rot in Southeastern Cotton (Gossypium hirsutum L.).

    PubMed

    Medrano, Enrique G; Bell, Alois A; Greene, Jeremy K; Roberts, Phillip M; Bacheler, Jack S; Marois, James J; Wright, David L; Esquivel, Jesus F; Nichols, Robert L; Duke, Sara

    2015-08-01

    In 1999, crop consultants scouting for stink bugs (Hemiptera spp.) in South Carolina discovered a formerly unobserved seed rot of cotton that caused yield losses ranging from 10 to 15% in certain fields. The disease has subsequently been reported in fields throughout the southeastern Cotton Belt. Externally, diseased bolls appeared undamaged; internally, green fruit contain pink to dark brown, damp, deformed lint, and necrotic seeds. In greenhouse experiments, we demonstrated transmission of the opportunistic bacterium Pantoea agglomerans by the southern green stink bug, Nezara viridula (L.). Here, green bolls were sampled from stink bug management plots (insecticide protected or nontreated) from four South Atlantic coast states (North Carolina, South Carolina, Georgia, and Florida) to determine disease incidence in the field and its association with piercing-sucking insects feeding. A logistic regression analysis of the boll damage data revealed that disease was 24 times more likely to occur (P = 0.004) in bolls collected from plots in Florida, where evidence of pest pressure was highest, than in bolls harvested in NC with the lowest detected insect pressure. Fruit from plots treated with insecticide, a treatment which reduced transmission agent numbers, were 4 times less likely to be diseased than bolls from unprotected sites (P = 0.002). Overall, punctured bolls were 125 times more likely to also have disease symptoms than nonpunctured bolls, irrespective of whether or not plots were protected with insecticides (P = 0.0001). Much of the damage to cotton bolls that is commonly attributed to stink bug feeding is likely the resulting effect of vectored pathogens.

  3. In vivo bioinsecticidal activity toward Ceratitis capitata (fruit fly) and Callosobruchus maculatus (cowpea weevil) and in vitro bioinsecticidal activity toward different orders of insect pests of a trypsin inhibitor purified from tamarind tree (Tamarindus indica) seeds.

    PubMed

    Araújo, Carina L; Bezerra, Ingrid W L; Oliveira, Adeliana S; Moura, Fabiano T; Macedo, Leonardo L P; Gomes, Carlos E M; Barbosa, Aulus E A D; Macedo, Francisco P; Souza, Tánia M S; Franco, Octavio L; Bloch-J, Carlos; Sales, Mauricio P

    2005-06-01

    A proteinaceous inhibitor with high activity against trypsin-like serine proteinases was purified from seeds of the tamarind tree (Tamarindus indica) by gel filtration on Shephacryl S-200 followed by a reverse-phase HPLC Vidac C18 TP. The inhibitor, called the tamarind trypsin inhibitor (TTI), showed a Mr of 21.42 kDa by mass spectrometry analysis. TTI was a noncompetitive inhibitor with a Ki value of 1.7 x 10(-9) M. In vitro bioinsecticidal activity against insect digestive enzymes from different orders showed that TTI had remarkable activity against enzymes from coleopteran, Anthonomus grandis (29.6%), Zabrotes subfasciatus (51.6%), Callosobruchus maculatus (86.7%), Rhyzopertha dominica(88.2%), and lepidopteron, Plodia interpuncptella (26.7%), Alabama argillacea (53.8%), and Spodoptera frugiperda (75.5%). Also, digestive enzymes from Diptera, Ceratitis capitata (fruit fly), were inhibited (52.9%). In vivo bioinsecticidal assays toward C. capitata and C. maculatus larvae were developed. The concentration of TTI (w/w) in the artificial seed necessary to cause 50% mortality (LD50) of larvae was 3.6%, and that to reduce mass larvae by 50.0% (ED50) was 3.2%. Furthermore, the mass C. capitata larvae were affected at 53.2% and produced approximately 34% mortality at a level of 4.0% (w/w) of TTI incorporated in artificial diets.

  4. Host-mediated induction of alpha-amylases by larvae of the Mexican bean weevil Zabrotes subfasciatus (Coleoptera: Chrysomelidae: Bruchinae) is irreversible and observed from the initiation of the feeding period.

    PubMed

    Bifano, Thaís D; Samuels, Richard I; Alexandre, Daniel; Silva, Carlos P

    2010-08-01

    Larvae of Zabrotes subfasciatus secrete alpha-amylases that are insensitive to the alpha-amylase inhibitor found in seeds of Phaseolus vulgaris. By analyzing amylase activities during larval development on P. vulgaris, we detected activity of the constitutive amylase and the two inducible amylase isoforms at all stages. When larvae were transferred from the non alpha-amylase inhibitor containing seeds of Vigna unguiculata to P. vulgaris, the inducible alpha-amylases were expressed at the same level as in control larvae fed on P. vulgaris. Interestingly, when larvae were transferred from seeds of P. vulgaris to those of V. unguiculata, inducible alpha-amylases continued to be expressed at a level similar to that found in control larvae fed P. vulgaris continuously. When 10-day-old larvae were removed from seeds of V. unguiculata and transferred into capsules containing flour of P. vulgaris cotyledons, and thus maintained until completing 17 days (age when the larvae stopped feeding), we could detect higher activity of the inducible alpha-amylases. However, when larvae of the same age were transferred from P. vulgaris into capsules containing flour of V. unguiculata, the inducible alpha-amylases remained up-regulated. These results suggest that the larvae of Z. subfasciatus have the ability to induce insensitive amylases early in their development. A short period of feeding on P. vulgaris cotyledon flour was sufficient to irreversibly induce the inducible alpha-amylase isoforms. Incubations of brush border membrane vesicles with the alpha-amylase inhibitor 1 from P. vulgaris suggest that the inhibitor is recognized by putative receptors found in the midgut microvillar membranes.

  5. Immatures of Palaearctic species of the weevil genus Tychius (Coleoptera, Curculionidae): new descriptions and new bionomic data with an evaluation of their value in a phylogenetic reconstruction of the genus .

    PubMed

    Skuhrovec, Jiří; Gosik, Rafał; Caldara, Roberto

    2014-07-23

    Larvae of 14 species and pupae of 12 species of Palaearctic Tychius Germar, 1817 are described for the first time. Larvae and pupae of T.meliloti Stephens, 1831, T. squamulatus Gyllenhal, 1835 and T. quinquepunctatus (Linnaeus, 1758), are redescribed with addition of new characters. They belong to 10 of 22 groups of species assembled through adult morphological characters in this region and, like all other Tychius with known biology, the studied species live on Leguminosae Papilionoideae, belonging to the tribes Genisteae, Loteae, Galegeae, Trifolieae and Vicieae. Generally larvae, but not pupae, show a few characters useful to support some groupings previously postulated on adult morphology, and also suggest some phylogenetic relationships among groups although these are partly weak because of several clear parallelisms or convergences. One of the most numerous and better known group of species, the T. stephensi group living on Trifolieae, is supported by two distinctive larval character states, whereas all the other groups seem to be distinguishable from each other at least by a unique larval character state. New bionomic data concerning larval and pupal development and adult emergence are reported for all the described species. These data confirm that this genus is highly homogeneous in habits and times of development, with unique adaptive differences in adult emergence and overwintering according to the single or double seasonal flowering of the host plant. On the basis of morphological characters of immatures and adults, a possible concordance between the evolution of Tychius and that of their host plants is discussed.

  6. Species-specific defense reactions and avoidance learning. An evaluative review.

    PubMed

    Crawford, M; Masterson, F A

    1982-01-01

    Bolles (1970) proposed a theory of avoidance learning, the species-specific defense reaction (SSDR) hypothesis, which emphasized innate constraints on the response repertoire of rats in aversive situations and minimized the role of reinforcement in avoidance learning. The present paper describes Bolles' (1970, 1971, 1972, 1975, 1978) development of SSDR theory and reviews the empirical tests of its assumptions and predictions. It is concluded that the SSDRs described by Bolles, along with some others, are highly probable in aversive situations but that the response repertoire is not limited to them. Further, there is strong evidence for reinforcement effects in the establishment and maintenance of at least some avoidance responses.

  7. Occurrence of Panagrellus (Rhabditida: Panagrolaimidae) nematodes in a morphologically aberrant adult specimen of Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An aberrant specimen of Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) also known as Red Palm Weevil, the most economically important insect pest of palms in the world, was found among a batch of conspecifics reared for research purposes. A morphological analysis of this weevil revealed the ...

  8. A novel discovery in the pecan weevil’s pupal cell may lead to a new control method for pecan diseases such as scab

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil-dwelling insects have developed various mechanisms to defend against pathogens (disease causing agents) that also dwell in the soil. The pecan weevil, Curculio caryae, spends two to three years in the soil inside an earthen cell (also called its pupal cell or soil cell). To facilitate weevil s...

  9. Evidence of establishment of Bagous hydrillae Coleoptera: Curculionidae), a biological control agent of Hydrilla verticillata (Hydrocharitales: Hydirocharitaceae) in North America?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The semi-aquatic weevil Bagous hydrillae was released during 1991-1996 at 19 sites in four states in attempts to control the aquatic weed hydrilla, Hydrilla verticillata. Fourteen of the sites were in Florida, two each in Texas and Georgia and one site in Alabama. Over 320,000 adult weevils were i...

  10. Basil oil fumigation increases radiation sensitivity in adult Sitophilus oryzae (Coleoptera: Curculionidae).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biological activity of basil (Ocimum basilicum L.) oil was tested against the stored product pest rice weevil, Sitophilus oryzae(L.). Adult weevils were exposed to seven different concentrations of basil oil ranging from 0.12 µl/ml-0.60 µl/ml in Petri dishes and mortality was assessed at 3,4 and...

  11. Stored wheat insect infestation related to uric acid as determined by liquid chromatography.

    PubMed

    Wehling, R L; Wetzel, D L; Pedersen, J R

    1984-01-01

    Liquid chromatography is used to measure the uric acid content of wheat internally infested by various growth stages of granary weevil (Sitophilus granarius), rice weevil (Sitophilus oryzae), and lesser grain borer (Ryzopertha dominica). Good correlation exists between numbers of insects and uric acid content of grain infested by a given stage of an internally infesting stored product insect, with correlation coefficients ranging from 0.970 to 0.998. Uric acid content of infested grain increases as the insect life cycle progresses, with granary weevil producing the greatest quantities of uric acid followed in order by rice weevil and lesser grain borer. A detection limit for the analytical procedure of less than 1.0 ppm uric acid allows detection of infestation levels as low as one kernel per 100 g grain for late instar granary weevil larvae. This limit is sufficiently sensitive to detect levels of infestation that may be commonly encountered in commerce.

  12. Antiquity of American Polyploid Cotton.

    PubMed

    Smith, C E; Macneish, R S

    1964-02-14

    Fragments of a boll of Gossypium hirsutum L. from archeological excavations near Tehuacán, Mexico, prove that this species existed in 5800 B. C. No doubt remains that American tetraploid cotton species originated through natural hiybridization.

  13. 78 FR 26614 - Narrow Woven Ribbon With Woven Selvedge From the People's Republic of China: Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-07

    ... International Trade Administration Narrow Woven Ribbon With Woven Selvedge From the People's Republic of China: Rescission of Antidumping Duty Administrative Review; 2011-2012 AGENCY: Import Administration, International... Robert Bolling, AD/ CVD Operations, Office 4, Import Administration, International Trade...

  14. Early Brain Stimulation May Help Stroke Survivors Recover Language Function

    MedlinePlus

    ... in 2013. The Walter and Marga Boll and Wolf-Dieter-Heiss Foundations funded the current study. Co- ... Kessler, Ph.D.; Thomas Rommel, M.D.; and Wolf-Dieter Heiss, M.D. Author disclosures are on ...

  15. Plant growth stage-specific injury and economic injury level for verde plant bug, Creontiades signatus (Hemiptera: Miridae), on cotton: effect of bloom period of infestation.

    PubMed

    Brewer, Michael J; Anderson, Darwin J; Armstrong, J Scott

    2013-10-01

    Verde plant bugs, Creontiades signatus Distant (Hemiptera: Miridae), were released onto caged cotton, Cossypium hirsutum L., for a 1-wk period to characterize the effects of insect density and bloom period of infestation on cotton injury and yield in 2011 and 2012, Corpus Christi, TX. When plants were infested during early bloom (10-11 nodes above first white flower), a linear decline in fruit retention and boll load and a linear increase in boll injury were detected as verde plant bug infestation levels increased from an average of 0.5 to 4 bugs per plant. Lint and seed yield per plant showed a corresponding decline. Fruit retention, boll load, and yield were not affected on plants infested 1 wk later at peak bloom (8-9 nodes above first white flower), even though boll injury increased as infestation levels increased. Second-year testing verified boll injury but not yield loss, when infestations occurred at peak bloom. Incidence of cotton boll rot, known to be associated with verde plant bug feeding, was low to modest (< 1% [2012] to 12% [2011] of bolls with disease symptoms), and drought stress persisted throughout the study. Caging effect was minimal: a 10% fruit retention decline was associated with caging, and the effect was not detectable in the other measurements. Overall, reduced fruit retention and boll load caused by verde plant bug were important contributors to yield decline, damage potential was greatest during the early bloom period of infestation, and a simple linear response best described the yield response-insect density relationship at early bloom. Confirmation that cotton after peak bloom was less prone to verde plant bug injury and an early bloom-specific economic injury level were key findings that can improve integrated pest management decision-making for dryland cotton, at least under low-rainfall growing conditions.

  16. The functional significance of aposematic signals: geographic variation in the responses of widespread lizard predators to colourful invertebrate prey.

    PubMed

    Tseng, Hui-Yun; Lin, Chung-Ping; Hsu, Jung-Ya; Pike, David A; Huang, Wen-San

    2014-01-01

    Conspicuous colouration can evolve as a primary defence mechanism that advertises unprofitability and discourages predatory attacks. Geographic overlap is a primary determinant of whether individual predators encounter, and thus learn to avoid, such aposematic prey. We experimentally tested whether the conspicuous colouration displayed by Old World pachyrhynchid weevils (Pachyrhynchus tobafolius and Kashotonus multipunctatus) deters predation by visual predators (Swinhoe's tree lizard; Agamidae, Japalura swinhonis). During staged encounters, sympatric lizards attacked weevils without conspicuous patterns at higher rates than weevils with intact conspicuous patterns, whereas allopatric lizards attacked weevils with intact patterns at higher rates than sympatric lizards. Sympatric lizards also attacked masked weevils at lower rates, suggesting that other attributes of the weevils (size/shape/smell) also facilitate recognition. Allopatric lizards rapidly learned to avoid weevils after only a single encounter, and maintained aversive behaviours for more than three weeks. The imperfect ability of visual predators to recognize potential prey as unpalatable, both in the presence and absence of the aposematic signal, may help explain how diverse forms of mimicry exploit the predator's visual system to deter predation.

  17. Identification of rice cultivars resistant to Lissorhoptrus oryzophilus (Coleoptera: Curculionidae), and their use in an integrated management program.

    PubMed

    Stout, M J; Rice, W C; Linscombe, S D; Bollich, P K

    2001-08-01

    The rice water weevil, Lissorhoptrus oryzophilus Kuschel, is the most destructive insect pest of rice in the United States and is a particularly severe pest in Louisiana. The current management program for this insect in Louisiana relies heavily on insecticides, most notably the seed treatment fipronil (Icon). Diversification of the management program by incorporation of alternative strategies is needed to improve the effectiveness and long-term stability of the program. In the three experiments reported here, three components of a diversified management program for the rice water weevil in Louisiana--host plant resistance, treatment of seeds with Icon, aid the cultural practice of delayed flooding--were investigated. Comparison of the densities of weevil larvae on the roots of several commercial cultivars indicated that the long-grain cultivar 'Jefferson' was more resistant to infestation by the rice water weevil than the other cultivars. The medium-grain cultivars 'Bengal', 'Earl' and 'Mars' and the long-grain variety 'Cocodrie' were the most susceptible to infestation. Comparison of yield data from untreated plots and plots treated with Icon indicated that the long-grain cultivars Cocodrie, Lemont, and Jefferson were more tolerant of weevil injury than the other cultivars. A 2-wk delay in flooding was associated with yield benefits in plots not treated with Icon. Treatment of seeds with Icon controlled weevils in all three screening experiments. The implications of these results for the development of an integrated management program for the rice water weevil are discussed.

  18. Efficacy of Selected Insecticides Applied to Hybrid Rice Seed

    PubMed Central

    Adams, A.; Gore, J.; Musser, F.; Cook, D.; Walker, T.; Dobbins, C.

    2016-01-01

    Hybrid rice and insecticide seed treatments targeting rice water weevil, Lissorhoptrus oryzophilus Kuschel, have altered the landscape of rice production. The effect of reduced seeding rates on seed treatment efficacy in hybrid rice has not been studied. During 2011 and 2012, an experiment was conducted at seven locations to determine the relationship between low seeding rates used in hybrid rice and efficacy of selected insecticidal seed treatments as measured by rice water weevil densities and yield. Labeled rates of thiamethoxam, chlorantraniliprole, and clothianidin were compared with higher rates of these products to determine if labeled rates provide an acceptable level of control of the rice water weevil. Study locations were divided into low, moderate, and high groups based on rice water weevil larval densities. All seed treatments and seed treatment rates reduced rice water weevil densities. However, there was no observed yield or economic benefit from the use of an insecticidal seed treatment in areas of low pressure. Differences in yield were observed among seed treatments and seed treatment rates in moderate and high pressure locations, and all seed treatments yielded better than the untreated plots, but these differences were not always economical. All seed treatments showed an economic advantage in areas of high weevil pressure, and there were no differences among seed treatment products or rates, suggesting that currently labeled seed treatment rates in hybrid rice are effective for rice water weevil management. PMID:26537671

  19. Efficacy of Selected Insecticides Applied to Hybrid Rice Seed.

    PubMed

    Adams, A; Gore, J; Musser, F; Cook, D; Catchot, A; Walker, T; Dobbins, C

    2016-02-01

    Hybrid rice and insecticide seed treatments targeting rice water weevil, Lissorhoptrus oryzophilus Kuschel, have altered the landscape of rice production. The effect of reduced seeding rates on seed treatment efficacy in hybrid rice has not been studied. During 2011 and 2012, an experiment was conducted at seven locations to determine the relationship between low seeding rates used in hybrid rice and efficacy of selected insecticidal seed treatments as measured by rice water weevil densities and yield. Labeled rates of thiamethoxam, chlorantraniliprole, and clothianidin were compared with higher rates of these products to determine if labeled rates provide an acceptable level of control of the rice water weevil. Study locations were divided into low, moderate, and high groups based on rice water weevil larval densities. All seed treatments and seed treatment rates reduced rice water weevil densities. However, there was no observed yield or economic benefit from the use of an insecticidal seed treatment in areas of low pressure. Differences in yield were observed among seed treatments and seed treatment rates in moderate and high pressure locations, and all seed treatments yielded better than the untreated plots, but these differences were not always economical. All seed treatments showed an economic advantage in areas of high weevil pressure, and there were no differences among seed treatment products or rates, suggesting that currently labeled seed treatment rates in hybrid rice are effective for rice water weevil management. PMID:26537671

  20. The Functional Significance of Aposematic Signals: Geographic Variation in the Responses of Widespread Lizard Predators to Colourful Invertebrate Prey

    PubMed Central

    Tseng, Hui-Yun; Lin, Chung-Ping; Hsu, Jung-Ya; Pike, David A.; Huang, Wen-San

    2014-01-01

    Conspicuous colouration can evolve as a primary defence mechanism that advertises unprofitability and discourages predatory attacks. Geographic overlap is a primary determinant of whether individual predators encounter, and thus learn to avoid, such aposematic prey. We experimentally tested whether the conspicuous colouration displayed by Old World pachyrhynchid weevils (Pachyrhynchus tobafolius and Kashotonus multipunctatus) deters predation by visual predators (Swinhoe’s tree lizard; Agamidae, Japalura swinhonis). During staged encounters, sympatric lizards attacked weevils without conspicuous patterns at higher rates than weevils with intact conspicuous patterns, whereas allopatric lizards attacked weevils with intact patterns at higher rates than sympatric lizards. Sympatric lizards also attacked masked weevils at lower rates, suggesting that other attributes of the weevils (size/shape/smell) also facilitate recognition. Allopatric lizards rapidly learned to avoid weevils after only a single encounter, and maintained aversive behaviours for more than three weeks. The imperfect ability of visual predators to recognize potential prey as unpalatable, both in the presence and absence of the aposematic signal, may help explain how diverse forms of mimicry exploit the predator’s visual system to deter predation. PMID:24614681

  1. Use of gamma radiation as a form of preservation of sweet potatoes. (Final technical) quarterly progress report

    SciTech Connect

    Not Available

    1985-01-01

    This document covers: harvest and conditioning following harvest, harvest-curing-storage-irradiation schemes, irradiation, control sweet potatoes, analyses, enzymes results, and procedures for taste evaluation, storage rot, weevil. (DLC)

  2. 7 CFR 319.56-40 - Peppers from certain Central American countries.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... country for the weevil Faustinus ovatipennis, pea leafminer, tomato fruit borer, banana moth, lantana... Faustinus ovatipennis, pea leafminer, tomato fruit borer, banana moth, lantana mealybug, passionvine... borer, banana moth, lantana mealybug, passionvine mealybug, melon thrips, the rust fungus...

  3. Efficacy of deltamethrin against stored-product beetles at short exposure intervals or on a partially-treated rice mass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stored product insects can potentially be exposed to grain protectants for variable time periods. Adults of six species, the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the granary weevil Sitophilus granarius (L.) (Coleoptera: Curculionidae), and the red flour beetle, ...

  4. Insecticidal effect of spinosad dust, in combination with diatomaceous earth, against two stored-grain beetle species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficacy of the biological insecticide spinosad applied alone and combination with diatomaceous earth (DE) was determined through laboratory bioassays with adults of the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and the confused flour beetle, Tribolium confusum Jacquelin du Val...

  5. Praecocilenchus rhaphidophorus n. gen., n. sp. (Nematoda: Aphelenchoidea) Parasitizing Rhynchophorus bilineatus (Montrouzier) (Coleoptera: Curculionidae) in New Britain

    PubMed Central

    Poinar, G. O.

    1969-01-01

    Praecocilenchus rhaphidophorus n. gen., n. sp. is described as a new endoparasitic aphelenchoid nematode parasitizing adults of the palm weevil, Rhynchophorus bilineatus (Montrouzier). P. rhaphidophorus is unusual in that juveniles develop to maturity within the female uterus and thin, needle-shaped crystals form in the intestines of mature parasitic females. Hundreds of parasitic female nematodes were found in the body cavity of infected hosts. The role of this parasite as a biological control agent of Rhynchophorus weevils is discussed. PMID:19325682

  6. [Oviposition, development, and reproduction of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) fed on different hosts of economic importance].

    PubMed

    Barros, Eduardo M; Torres, Jorge B; Bueno, Adeney F

    2010-01-01

    The host selection for oviposition by Spodoptera frugiperda (J.E. Smith) among corn, millet, cotton and soybean, and its relationship with the biological characteristics were investigated. Free and non-choice tests for oviposition using plots containing five plants each, from each host in plastic greenhouse, resulted in similar oviposition preference among the host plants. In addition, selected biological characteristics of S. frugiperda were determined in the laboratory with larvae feeding on host leaves, and the combination of leaf and cotton boll. Neonate larvae exhibited low success of colonization on cotton boll compared to the leaves of all other hosts. Spodoptera frugiperda fed only on cotton bolls exhibited longer larval and pupal development, and longer adult life span; however with similar egg production. Larvae fed cotton leaves during six days and then transferred to cotton bolls, however, exhibited development and reproduction similar to those reared on corn or only on cotton leaves. Therefore, the variations on immature stages of S. frugiperda were not related with host selection for oviposition which was similar among the studied hosts. Based on our data, the millet as a winter, rotational, and cover crop is a potential host for S. frugiperda, while leaves and cotton bolls were diets of intermediate suitability as compared to corn and soybean leaves.

  7. Important photosynthetic contribution from the non-foliar green organs in cotton at the late growth stage.

    PubMed

    Hu, Yuan-Yuan; Zhang, Ya-Li; Luo, Hong-Hai; Li, Wei; Oguchi, Riichi; Fan, Da-Yong; Chow, Wah Soon; Zhang, Wang-Feng

    2012-02-01

    Non-foliar green organs are recognized as important carbon sources after leaves. However, the contribution of each organ to total yield has not been comprehensively studied in relation to the time-course of changes in surface area and photosynthetic activity of different organs at different growth stages. We studied the contribution of leaves, main stem, bracts and capsule wall in cotton by measuring their time-course of surface area development, O(2) evolution capacity and photosynthetic enzyme activity. Because of the early senescence of leaves, non-foliar organs increased their surface area up to 38.2% of total at late growth stage. Bracts and capsule wall showed less ontogenetic decrease in O(2) evolution capacity per area and photosynthetic enzyme activity than leaves at the late growth stage. The total capacity for O(2) evolution of stalks and bolls (bracts plus capsule wall) was 12.7 and 23.7% (total ca. 36.4%), respectively, as estimated by multiplying their surface area by their O(2) evolution capacity per area. We also kept the bolls (from 15 days after anthesis) or main stem (at the early full bolling stage) in darkness for comparison with non-darkened controls. Darkening the bolls and main stem reduced the boll weight by 24.1 and 9%, respectively, and the seed weight by 35.9 and 16.3%, respectively. We conclude that non-foliar organs significantly contribute to the yield at the late growth stage.

  8. Resistance of Trichoplusia ni Populations Selected by Bacillus thuringiensis Sprays to Cotton Plants Expressing Pyramided Bacillus thuringiensis Toxins Cry1Ac and Cry2Ab

    PubMed Central

    Kain, Wendy; Song, Xiaozhao; Janmaat, Alida F.; Zhao, Jian-Zhou; Myers, Judith; Shelton, Anthony M.

    2014-01-01

    Two populations of Trichoplusia ni that had developed resistance to Bacillus thuringiensis sprays (Bt sprays) in commercial greenhouse vegetable production were tested for resistance to Bt cotton (BollGard II) plants expressing pyramided Cry1Ac and Cry2Ab. The T. ni colonies resistant to Bacillus thuringiensis serovar kurstaki formulations were not only resistant to the Bt toxin Cry1Ac, as previously reported, but also had a high frequency of Cry2Ab-resistant alleles, exhibiting ca. 20% survival on BollGard II foliage. BollGard II-resistant T. ni strains were established by selection with BollGard II foliage to further remove Cry2Ab-sensitive alleles in the T. ni populations. The BollGard II-resistant strains showed incomplete resistance to BollGard II, with adjusted survival values of 0.50 to 0.78 after 7 days. The resistance to the dual-toxin cotton plants was conferred by two genetically independent resistance mechanisms: one to Cry1Ac and one to Cry2Ab. The 50% lethal concentration of Cry2Ab for the resistant strain was at least 1,467-fold that for the susceptible T. ni strain. The resistance to Cry2Ab in resistant T. ni was an autosomally inherited, incompletely recessive monogenic trait. Results from this study indicate that insect populations under selection by Bt sprays in agriculture can be resistant to multiple Bt toxins and may potentially confer resistance to multitoxin Bt crops. PMID:25480752

  9. [Effects of water and nitrogen regulation on the yield and water and nitrogen use efficiency of cotton in south Xinjiang, Northwest China under plastic mulched drip irrigation].

    PubMed

    Deng, Zhong; Bai, Dan; Zhai, Guo-Liang; Zong, Jie; Li, Ying; Cai, Jiu-Mao; Feng, Jun-Jie

    2013-09-01

    A field experiment with three irrigation amounts and five nitrogen application levels was conducted to investigate the effects of water and nitrogen regulation on the growth characteristics, yield component factors, and water and nitrogen use efficiency of cotton in south Xinjiang under mulched drip irrigation. With the increasing amount of irrigation, the plant height, leaf number on main stem, boll number, LAI, and dry matter accumulation in leaf and stem improved significantly, but the root growth was restrained. As compared with low and high irrigation amounts (4950 and 6750 mm x hm(-2), respectively), medium irrigation amount (5850 mm x hm(-2)) increased the available bolls per plant and the single boll mass averagely by 0.96 and 0.4 and by 0.22 and 0.11 g, respectively. When the nitrogen application level was 300 kg x hm(-2), as compared with other nitrogen application levels, the stem diameter increased significantly, and the growth of bud, boll, and root was accelerated. Moreover, the allocation ratio of dry matter from nutritional organs to reproductive organs under medium irrigation amount increased by 5.1% and 29.6% respectively, as compared with that under low and high irrigation amounts. Irrigation amount had significant effects on the cotton yield but little effects on the lint percentage, whereas nitrogen application level had definite effects on the cotton yield and lint percentage. However, low irrigation amount restrained the effects of nitrogen application on yield enhancement. In this experiment, when the irrigation amount was 5850 mm x hm(-2) and the nitrogen application level was 300 kg x hm(-2), the cotton grew healthily, the plant shape structure was optimized, the dry matter allocation to reproductive organs was promoted dramatically, the available bolls, single boll mass, and lint percentage increased, the cotton yield reached the highest (6992.33 kg x hm(-2)), and the water and nitrogen use efficiency amounted to 1.45 kg x m(-3) and 45

  10. Alternative stable states explain unpredictable biological control of Salvinia molesta in Kakadu.

    PubMed

    Schooler, Shon S; Salau, Buck; Julien, Mic H; Ives, Anthony R

    2011-02-01

    Suppression of the invasive plant Salvinia molesta by the salvinia weevil is an iconic example of successful biological control. However, in the billabongs (oxbow lakes) of Kakadu National Park, Australia, control is fitful and incomplete. By fitting a process-based nonlinear model to thirteen-year data sets from four billabongs, here we show that incomplete control can be explained by alternative stable states--one state in which salvinia is suppressed and the other in which salvinia escapes weevil control. The shifts between states are associated with annual flooding events. In some years, high water flow reduces weevil populations, allowing the shift from a controlled to an uncontrolled state; in other years, benign conditions for weevils promote the return shift to the controlled state. In most described ecological examples, transitions between alternative stable states are relatively rare, facilitated by slow-moving environmental changes, such as accumulated nutrient loading or climate change. The billabongs of Kakadu give a different manifestation of alternative stable states that generate complex and seemingly unpredictable dynamics. Because shifts between alternative stable states are stochastic, they present a potential management strategy to maximize effective biological control: when the domain of attraction to the state of salvinia control is approached, augmentation of the weevil population or reduction of the salvinia biomass may allow the lower state to trap the system. PMID:21293376

  11. Pollination of Australian Macrozamia cycads (Zamiaceae): effectiveness and behavior of specialist vectors in a dependent mutualism.

    PubMed

    Terry, L Irene; Walter, Gimme H; Donaldson, John S; Snow, Elizabeth; Forster, Paul I; Machin, Peter J

    2005-06-01

    Complementary field and laboratory tests confirmed and quantified the pollination abilities of Tranes sp. weevils and Cycadothrips chadwicki thrips, specialist insects of their respective cycad hosts, Macrozamia machinii and M. lucida. No agamospermous seeds were produced when both wind and insects were excluded from female cones; and the exclusion of wind-vectored pollen alone did not eliminate seed set, because insects were able to reach the cone. Based on enclosure pollination tests, each weevil pollinates an average 26.2 ovules per cone and each thrips 2.4 ovules per cone. These pollinators visited similar numbers of ovules per cone in fluorescent dye tests that traced insect movement through cones. Fluorescent dye granules deposited by Cycadothrips were concentrated around the micropyle of each visited ovule, the site of pollen droplet release, where pollen must be deposited to achieve pollination. In contrast, Tranes weevils left dye scattered on different areas of each visited ovule, indicating that chance plays a greater role in this system. Each weevil and 25 thrips delivered 6.2 and 5.2 pollen grains, respectively, on average, to each visited ovule per cone, based on examination of dissected pollen canals. In sum, the pollination potential of 25 Cycadothrips approximates that of one Tranes weevil.

  12. Genome Sequence of Pantoea annatis strain CFH 7-1, which is associated with a vector-borne cotton fruit disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea ananatis is a bacterium with versatile niches that vary from pathogenic to beneficial. We present the genome of strain CFH 7-1, which was recovered from a diseased greenhouse cotton boll previously caged with a field-collected cotton fleahopper (Pseudatomoscelis seriatus). These data will ...

  13. Trap Cropping Systems and a Physical Barrier for Suppression of Stink Bugs (Hemiptera: Pentatomidae) in Cotton.

    PubMed

    Tillman, P G; Khrimian, A; Cottrell, T E; Lou, X; Mizell, R F; Johnson, C J

    2015-10-01

    Euschistus servus (Say), Nezara viridula (L.), and Chinavia hilaris (Say) (Hemiptera: Pentatomidae) are economic pests of cotton in the coastal plain of the southeastern United States. The objective of this 2-yr study was to determine the ability of trap cropping systems, pheromone-baited stink bug traps, and a synthetic physical barrier at the peanut-to-cotton interface to manage stink bugs in cotton. The physical barrier was the most effective management tactic. Stink bug density in cotton was lowest for this treatment. In 2010, boll injury was lower for the physical barrier compared to the other treatments except for soybean with stink bug traps. In 2011, boll injury was lower for this treatment compared to the control. Soybean was an effective trap crop, reducing both stink bug density in cotton and boll injury regardless if used alone or in combination with either stink bug traps or buckwheat. Incorporation of buckwheat in soybean enhanced parasitism of E. servus egg masses by Telenomus podisi Ashmead in cotton. The insertion of eyelets in the lid of the insect-collecting device of a stink bug trap allowed adult stink bug parasitoids, but not E. servus, to escape. Stand-alone stink bug traps were not very effective in deterring colonization of cotton by stink bugs or reducing boll injury. The paucity of effective alternative control measures available for stink bug management justifies further full-scale evaluations into these management tactics for control of these pests in crops. PMID:26453721

  14. Polysaccharides from the wastes of some fruit and berry, vegetable, and technical crops

    SciTech Connect

    Rakhimov, D.A.; Khamidkhozhaev, S.A.; Kondratenko, E.S.; Yuldasheva, N.P.

    1985-07-01

    The fractional isolation of water-soluble polysaccharides and pectin substances has been carried out from the wastes of fruit and berry and vegetable crops: apples, quinces, grapes, and tomatoes, and also the valves of cotton bolls. The qualititative and quantitative monosaccharide compositions of the carbohydrates isolated have been determined, and the characteristics of the pectin substances are given.

  15. Attraction of a native Florida leafminer, Phyllocnistis insignis, to pheromone of an invasive citrus Leafminer, P. citrella.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We collected a native North American species, Phyllocnistis insignis (Frey & Boll) (Lepidoptera: Gracillariidae), in traps baited with a 3:1 blend of (Z,Z,E)-7,11,13-hexadecatrienal (triene) and (Z,Z)-7,11-hexadecadienal (diene), 2 components of the sex pheromone of the invasive citrus leafminer, P....

  16. Attraction of a native Florida leafminer, Phyllocnistis insignis (Lepidoptera: Gracillariidae), to pheromone of invasive citrus leafminer, P. citrella: Evidence for mating disruption of a native nontarget species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We collected a native North American species, Phyllocnistis insignis (Frey & Boll), in traps baited with a 3:1 blend of (Z,Z,E)-7,11,13-hexadecatrienal (triene) and (Z,Z)-7,11-hexadecadienal (diene), two components of the sex pheromone of the exotic citrus leafminer, Phyllocnistis citrella Stainton....

  17. Development of a solar radiation stress index for cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Mid-South cotton fields, a marked increase in small boll abscission following a progression of cloudy days may be erroneously attributed to effects of arthropod pests. Zhao and Oosterhuis (2000) found that 4 days of shading impacted yield especially during the period of effective flowering and bo...

  18. 77 FR 58811 - Advisory Committee on Supply Chain Competitiveness Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-24

    ... administrative issues including ethics and privacy requirements, and select a Chairperson for the Committee. The... (202) 482-1135 or richard.boll@trade.gov five (5) business days before the meeting. Status: Interested...., Room 11014, Washington, DC 20230, or email to supplychain@trade.gov to be received by close of...

  19. Leading Court Decision Pertinent to Public School Desegregation.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on the Judiciary.

    This document comprises eight federal court decisions pertinent to public school desegregation: (1) "Brown v. Board of Education," 347 U.S. 483 (1954); Mr. Chief Justice Warren delivered the opinion of the Supreme Court; (2) "Bolling v. Sharpe," 374 U.S. 497 (1954); Mr. Chief Justice Warren delivered the opinion of the Supreme Court; (3) "Brown v.…

  20. Kinship in Mongolian Sign Language

    ERIC Educational Resources Information Center

    Geer, Leah

    2011-01-01

    Information and research on Mongolian Sign Language is scant. To date, only one dictionary is available in the United States (Badnaa and Boll 1995), and even that dictionary presents only a subset of the signs employed in Mongolia. The present study describes the kinship system used in Mongolian Sign Language (MSL) based on data elicited from…

  1. Germany in Europe 1963.

    ERIC Educational Resources Information Center

    Stanford Univ., CA.

    The results of the 10-week National Defense Education Act (NDEA) Third-Level Institute for Secondary School Teachers of German, conducted by Stanford University in Bad Boll, Germany, are compiled in individual reports written in both German and English by the 25 participants. Emphasizing close contact with the residents in their working and home…

  2. [Compensation effect of cotton growth and development after soil salt content reduction at bud stage].

    PubMed

    Guo, Wen-Qi; Zhang, Pei-Tong; Li, Chun-Hong; Yin, Jian-Mei; Han, Xiao-Yong

    2014-01-01

    To elucidate the dynamic characteristics of cotton growth and development after soil salt content reduction (SD) at bud stage and its effect on yield formation, a pot experiment was conducted in which soil salt content was declined from 5 per thousand level to 2 per thousand level at cotton bud stage. The results showed that the plant height, biomass, total fruit branch and fruit node number, boll number, boll mass of cotton plants increased after soil salt content reduction at bud stage. The distribution proportions of biomass in root and boll decreased after soil salt content reduction, however, the distribution proportions of biomass in leaf, main stem and fruit branch were on the rise. The growth rate of cotton plant increased after soil salt content reduction. Plant dry matter accumulation rate of SD cotton exceeded CK cotton at 22 days after soil salt content reduction. The response of different organs of cotton plant were different to soil salt content reduction, the plant height was the earliest, followed by the fruit branch and fruit node formation, and the bud and boll were the latest, which indicated that the compensation effect of cotton growth and development after soil salt content reduction at bud stage firstly appeared on the formation and growth of new leaf, fruit branch and fruit node, and on this basis, gradually brought out yield compensation.

  3. Tracking cotton fiber quality throughout a stipper harvester: Part II

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fiber quality begins to degrade naturally with the opening of the boll and mechanical harvesting processes are perceived to exacerbate fiber degradation. Previous research indicates that stripper harvested cotton generally has lower fiber quality and higher foreign matter content than picker ...

  4. Comparison of a wire belt conveyor and cross auger conveyor for conveying burr cotton on a stripper harvester

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fiber quality begins to degrade naturally with the opening of the boll, and mechanical harvesting processes are perceived to exacerbate fiber degradation. Previous research indicates that stripper-harvested cotton generally has lower fiber quality including on average lower micronaire, length...

  5. Use of irradiation as quarantine treatment for agricultural products infested by mites and insects

    NASA Astrophysics Data System (ADS)

    Ignatowicz, S.; Brzostek, G.

    The criterion for efficacy of irradiation of agricultural products as a quarantine treatment should be based on the inability to perpetuate the pest at a new location rather than in causing immediate mortality. Sterility in insects and mites is achieved following irradiation of adults and immatures at much lower doses than needed to kill these pests. Irradiation of beans infested by the bean weevil, Acanthoscelidesobtectus Say, and grains infested by the grain weevil, Sitophilusgranarius (L.), and/or the rice weevil, S. oryzae (L.), at 60 Gy could be the treatment required to produce an acceptable level of quarantine security. For the acarid mites ( Acaridae), a dose of 250 Gy is suggested. At these dosages, adult survivors of the pest will be present in the treated commodities, but they will not give rise to offspring, and thus this pest would not be able to perpetuate in a new area.

  6. New records for Euhrychiopsis Lecontei (Coleoptera: Curculionidae) and their densities in Wisconsin lakes

    USGS Publications Warehouse

    Jester, L.L.; Bozek, Michael A.; Sheldon, S.P.; Helsel, D.R.

    1997-01-01

    The native aquatic weevil, Euhrychiopsis lecontei is currently being researched as a potential biological control for the exotic aquatic macrophyte Eurasian watermilfoil (Myriophyllum spicatum), yet little is known about its specific distribution in North America. In this study, E. lecontei was collected in 25 of 27 lakes surveyed for the weevil in Wisconsin, greatly increasing the known distribution of the species in this state. E. lecontei densities evaluated in 14 Wisconsin lakes ranged from <0.01 to 1.91 weevils per apical stem of milfoil. These new records indicate that E. lecontei is widespread throughout Wisconsin and is associated with natural declines of M. spicatum in some lakes. Additional sampling for E. lecontei and research on its ecology and life history are needed to understand the role of this organism in aquatic ecosystems.

  7. Effect of mechanical stress on cotton growth and development.

    PubMed

    Zhang, Zhiyong; Zhang, Xin; Wang, Sufang; Xin, Wanwan; Tang, Juxiang; Wang, Qinglian

    2013-01-01

    Agricultural crops experience diverse mechanical stimuli, which may affect their growth and development. This study was conducted to investigate the effects of mechanical stresses caused by hanging labels from the flower petioles (HLFP) on plant shape and cotton yields in four cotton varieties: CCRI 41, DP 99B, CCRC 21, and BAI 1. HLFP significantly reduced plant height by between 7.8% and 36.5% in all four lines and also significantly reduced the number of fruiting positions per plant in the CCRI 41, DP 99B and CCRC 21 lines. However, the number of fruiting positions in BAI 1 was unaffected. HLFP also significantly reduced the boll weight for all four cultivars and the seed cotton yields for CCRI 41, DP 99B and BAI 1. Conversely, it significantly increased the seed cotton yield for CCRC 21 by 11.2%. HLFP treatment did not significantly affect the boll count in the fruiting branches of the 1(st) and 2(nd) layers in any variety, but did significantly reduce those on the 3(rd) and 4(th) fruiting branch layers for CCRI 41 and DP 99B. Similar trends were observed for the number of bolls per FP. In general, HLFP reduced plant height and boll weight. However, the lines responded differently to HLFP treatment in terms of their total numbers of fruiting positions, boll numbers, seed cotton yields, etc. Our results also suggested that HFLP responses might be delayed for some agronomy traits of some cotton genotypes, and that hanging labels from early-opening flowers might influence the properties related with those that opened later on.

  8. Downstairs drivers--root herbivores shape communities of above-ground herbivores and natural enemies via changes in plant nutrients.

    PubMed

    Johnson, Scott N; Mitchell, Carolyn; McNicol, James W; Thompson, Jacqueline; Karley, Alison J

    2013-09-01

    1. Terrestrial food webs are woven from complex interactions, often underpinned by plant-mediated interactions between herbivores and higher trophic groups. Below- and above-ground herbivores can influence one another via induced changes to a shared host plant, potentially shaping the wider community. However, empirical evidence linking laboratory observations to natural field populations has so far been elusive. 2. This study investigated how root-feeding weevils (Otiorhynchus sulcatus) influence different feeding guilds of herbivore (phloem-feeding aphids, Cryptomyzus galeopsidis, and leaf-chewing sawflies, Nematus olfaciens) in both controlled and field conditions. 3. We hypothesized that root herbivore-induced changes in plant nutrients (C, N, P and amino acids) and defensive compounds (phenolics) would underpin the interactions between root and foliar herbivores, and ultimately populations of natural enemies of the foliar herbivores in the field. 4. Weevils increased field populations of aphids by ca. 700%, which was followed by an increase in the abundance of aphid natural enemies. Weevils increased the proportion of foliar essential amino acids, and this change was positively correlated with aphid abundance, which increased by 90% on plants with weevils in controlled experiments. 5. In contrast, sawfly populations were 77% smaller during mid-June and adult emergence delayed by >14 days on plants with weevils. In controlled experiments, weevils impaired sawfly growth by 18%, which correlated with 35% reductions in leaf phosphorus caused by root herbivory, a previously unreported mechanism for above-ground-below-ground herbivore interactions. 6. This represents a clear demonstration of root herbivores affecting foliar herbivore community composition and natural enemy abundance in the field via two distinct plant-mediated nutritional mechanisms. Aphid populations, in particular, were initially driven by bottom-up effects (i.e. plant-mediated effects of root

  9. An insecticidal N-acetylglucosamine-specific lectin gene from Griffonia simplicifolia (Leguminosae).

    PubMed Central

    Zhu, K; Huesing, J E; Shade, R E; Bressan, R A; Hasegawa, P M; Murdock, L L

    1996-01-01

    Griffonia simplicifolia II, an N-acetylglucosamine-specific legume lectin, has insecticidal activity when fed to the cowpea weevil, Callosobruchus maculatus (F.). A cDNA clone encoding G. simplicifolia II was isolated from a leaf cDNA library, sequenced, and expressed in a bacterial expression system. The recombinant protein exhibited N-acetylglucosamine-binding and insecticidal activity against cowpea weevil, indicating that glycosylation and multimeric structure are not required for these properties. These results support the hypothesis that genes of the legume lectin gene family encode proteins that function in plant defense against herbivores. PMID:8587982

  10. Micro-pixelation and color mixing in biological photonic structures (presentation video)

    NASA Astrophysics Data System (ADS)

    Bartl, Michael H.; Nagi, Ramneet K.

    2014-03-01

    The world of insects displays myriad hues of coloration effects produced by elaborate nano-scale architectures built into wings and exoskeleton. For example, we have recently found many weevils possess photonic architectures with cubic lattices. In this talk, we will present high-resolution three-dimensional reconstructions of weevil photonic structures with diamond and gyroid lattices. Moreover, by reconstructing entire scales we found arrays of single-crystalline domains, each oriented such that only selected crystal faces are visible to an observer. This pixel-like arrangement is key to the angle-independent coloration typical of weevils—a strategy that could enable a new generation of coating technologies.

  11. Perapion connexum (Schilsky, 1902) (Coleoptera, Apionidae) in Central Europe, a case of plant expansion chase

    PubMed Central

    Wanat, Marek; Podlussány, Attila; Schön, Karel

    2012-01-01

    Abstract Perapion connexum (Schilsky) is recorded for the first time from Hungary and Kyrgyzstan, and new distribution data from Ukraine and Russia are provided. Preliminary placements of this weevil in faunal checklists for Poland and Slovakia are here documented with detailed data. Its occurrence in Austria based on older evidence, is discussed. The neophytic and invasive in Central Europe sorrel Rumex confertus Willd. is confirmed to be its unique host plant in Poland. Morphology of the newcoming weevil is described and illustrated, and the key to all Central European species of Perapion is presented. PMID:22451784

  12. [Evaluation of specific activity of preparations of allergens from synanthropic insects].

    PubMed

    Berzhets, V M; Radikova, O V; Khlgatian, S V; Berzhets, A I; Kropotova, I S

    2006-01-01

    Physical, chemical and immunobiological characteristics of allergens from synanthropic insects were studied by tests for anaphylaxis, indirect degranulation of mast cells test and ELISA. Sera from 20 patients with severe and intermediate atopic asthma with sensiblization to common allergens have been studied. All extracts of allergens from synanthropic insects (german cockroach, oriental cockroach, american cockroach, speckled feeder cockroach, cricket, common house fly, brown house moth, confused flour beetle, rice weevil, grain weevil) have specific activity. Extracts of allergens from common house fly, brown house moth, german cockroach and oriental cockroach had the strongest allergenic activity as measured by ELISA. Obtained allergens can be used for insect allergy diagnostics.

  13. Effects of flameless catalytic infrared radiation on Sitophilus oryzae (L.) life stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A laboratory bench top flameless catalytic infrared emitter was evaluated against all life stages of the rice weevil, Sitophilus oryzae (L.), an insect species associated with stored wheat. The infrared radiation emitted was in the 3 to 7 µm range. A non-contact infrared thermometer measured grain t...

  14. Use of gamma radiation as a form of preservation of sweet potatoes

    NASA Astrophysics Data System (ADS)

    The effects of (GAMMA) radiation on the sweet potato weevil, organoleptic properties of sweet potatoes, protein content of same, and sweet potato quality (vitamins, color, texture, and carbohydrates) are discussed. Evaluation of preliminary results indicate that changes should be made in irradiation procedures/conditions and analyses.

  15. Ecologia quimica y expansion geografica del gorgojo polifago Diaprepes abbreviatus (Coleoptera: Curculionidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The tropical root weevil, Diaprepes abbreviatus (L.), has been a pest of citrus and ornamental plants since its introduction into Lake County, FL in 1964. Since then, it has colonized the Florida peninsula to the south of its point of introduction, but has not expanded its range to the north. A lowe...

  16. 76 FR 65988 - Importation of Mangoes From Australia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-25

    ... mitigation measures for the fungus Cytosphaera mangiferae and would have to be inspected prior to exportation... Mango seed weevil (Sternochetus mangiferae) Fungi Cytosphaera mangiferae Fusarium spp. complex... States. The required irradiation treatment would not mitigate the risks posed by the fungus C....

  17. Temporal and spectral features of sounds of wood-boring beetle larvae: identifiable patterns of activity enable improved discrimination from background noise

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhynchophorus weevil larvae produce economically important damage to ornamental and date palm crops that could be mitigated significantly by early detection and treatment. Acoustic technology has potential to enable early detection, but often it is difficult to distinguish insect sounds from backgr...

  18. Using hyperspectral reflectance data to assess biocontrol damage to giant salvinia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field hyperspectral reflectance data were studied at 50 wavebands (10 nm bandwidth) over the 400 to 900 nm spectral range to determine their potential for distinguishing among giant salvinia (Salvinia molesta Mitchell) plants subjected to four population levels of salvinia weevils (Cyrtobagous salvi...

  19. The Scanning Electron Microscope and the Archaeologist

    ERIC Educational Resources Information Center

    Ponting, Matthew

    2004-01-01

    Images from scanning electron microscopy are now quite common and they can be of great value in archaeology. Techniques such as secondary electron imaging, backscattered electron imaging and energy-dispersive x-ray analysis can reveal information such as the presence of weevils in grain in Roman Britain, the composition of Roman coins and the…

  20. An insect pupal cell with antimicrobial properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil-dwelling insects have developed various defense mechanisms to defend against pathogen infection. The pecan weevil, Curculio caryae, spends two to three years in the soil inside an earthen cell. We hypothesized that the cell may possess antimicrobial properties. In a laboratory study, we teste...

  1. Flight capacity of Sitophilus zeamais Motschulsky in relation to gender and temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The maize weevil, Sitophilus zeamais, is a major pest of stored products worldwide. In this research, we evaluated the flight performance of S. zeamais under various temperatures using a 26-channel computer-monitored flight-mill system to estimate total flight distance (TFD), total flight duration (...

  2. Sunflower insect pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Like other annual crops, sunflowers are fed upon by a variety of insect pests capable of reducing yields. Though there are a few insects which are considered consistent or severe (e.g., sunflower moth, banded sunflower moth, red sunflower seed weevil), many more insects are capable of causing proble...

  3. 2009 Sunflower Insect Pest Problems and Insecticide Update

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sunflowers (Helianthus annuus L.) are native to North America and a number of insect pests cause economic losses to sunflower production. Head-infesting insects include the red sunflower seed weevil, Smicronyx fulvus LeConte, banded sunflower moth, Cochylis hospes Walsingham, sunflower moth, Homoeos...

  4. North Dakota Sunflower Insect Pest Survey, 2006-2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The major insect pest species that cause economic losses to sunflower producers in North Dakota are banded sunflower moth (Cochylis hospes Walsingham), red sunflower seed weevil (Smicronyx fulvus Le Conte), and sunflower midge (Contarinia schulzi Gagne). New emerging insect pests include lygus bugs ...

  5. Resistance among cultivated sunflower germplasm to stem-infesting pests in the central Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 7-year field study evaluated 61 sunflower accessions and 31 interspecific crosses for resistance to attack by naturally occurring populations of three stem-infesting pests, the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae), a longhorned beetle, Dectes texa...

  6. Impact of irrigation on larval density of stem-infesting pests of cultivated sunflower in Kansas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The guild of stem-infesting insect pests of cultivated sunflower, Helianthus annuus L., within the central Plains is a concern to producers chiefly due to losses caused by plant lodging from the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae) and Dectes texanu...

  7. Impact of combining planting date and chemical control to reduce larval densities of stem-infesting pests of sunflower in the Central Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The guild of stem-infesting insect pests of sunflower, Helianthus annuus L., within the central Plains is a concern to producers chiefly due to losses caused by plant lodging from the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae) and Dectes texanus texanus L...

  8. 7 CFR 319.56-40 - Peppers from certain Central American countries.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and... inspection of the growing site must be conducted by the national plant protection organization (NPPO) of the... exporting country, including any of the following pests: The weevil Faustinus ovatipennis, pea...

  9. Curculionoidea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter provides short descriptions, information on distribution, biology, host plants, ecology and relationships for 62 species of weevils representing all major subfamilies and subfamilies in Curculionoidea. High resolution images of each species is provided as well as an illustration of...

  10. Histology and cell wall biochemistry of stone cells in the physical defence of conifers against insects.

    PubMed

    Whitehill, Justin G A; Henderson, Hannah; Schuetz, Mathias; Skyba, Oleksandr; Yuen, Macaire Man Saint; King, John; Samuels, A Lacey; Mansfield, Shawn D; Bohlmann, Jörg

    2016-08-01

    Conifers possess an array of physical and chemical defences against stem-boring insects. Stone cells provide a physical defence associated with resistance against bark beetles and weevils. In Sitka spruce (Picea sitchensis), abundance of stone cells in the cortex of apical shoots is positively correlated with resistance to white pine weevil (Pissodes strobi). We identified histological, biochemical and molecular differences in the stone cell phenotype of weevil resistant (R) or susceptible (S) Sitka spruce genotypes. R trees displayed significantly higher quantities of cortical stone cells near the apical shoot node, the primary site for weevil feeding. Lignin, cellulose, xylan and mannan were the most abundant components of stone cell secondary walls, respectively. Lignin composition of stone cells isolated from R trees contained a higher percentage of G-lignin compared with S trees. Transcript profiling revealed higher transcript abundance in the R genotype of coumarate 3-hydroxylase, a key monolignol biosynthetic gene. Developing stone cells in current year apical shoots incorporated fluorescent-tagged monolignol into the secondary cell wall, while mature stone cells of previous year apical shoots did not. Stone cell development is an ephemeral process, and fortification of shoot tips in R trees is an effective strategy against insect feeding.

  11. Genomic Mining of Phylogenetically Informative Nuclear Markers in Bark and Ambrosia Beetles

    PubMed Central

    Pistone, Dario; Mugu, Sigrid; Jordal, Bjarte Henry

    2016-01-01

    Deep level insect relationships are generally difficult to resolve, especially within taxa of the most diverse and species rich holometabolous orders. In beetles, the major diversity occurs in the Phytophaga, including charismatic groups such as leaf beetles, longhorn beetles and weevils. Bark and ambrosia beetles are wood boring weevils that contribute 12 percent of the diversity encountered in Curculionidae, one of the largest families of beetles with more than 50000 described species. Phylogenetic resolution in groups of Cretaceous age has proven particularly difficult and requires large quantity of data. In this study, we investigated 100 nuclear genes in order to select a number of markers with low evolutionary rates and high phylogenetic signal. A PCR screening using degenerate primers was applied to 26 different weevil species. We obtained sequences from 57 of the 100 targeted genes. Sequences from each nuclear marker were aligned and examined for detecting multiple copies, pseudogenes and introns. Phylogenetic informativeness (PI) and the capacity for reconstruction of previously established phylogenetic relationships were used as proxies for selecting a subset of the 57 amplified genes. Finally, we selected 16 markers suitable for large-scale phylogenetics of Scolytinae and related weevil taxa. PMID:27668729

  12. Insect attack and wounding induce traumatic resin duct development and gene expression of (-)-pinene synthase in Sitka spruce.

    PubMed

    McKay, S Ashley Byun; Hunter, William L; Godard, Kimberley-Ann; Wang, Shawn X; Martin, Diane M; Bohlmann, Jörg; Plant, Aine L

    2003-09-01

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (-)-pinene synthase. The recombinant (-)-pinene synthase catalyzes the formation of (-)-alpha-pinene and (-)-beta-pinene, both of which are known constituents of stem oleoresin in Sitka spruce and increase in abundance after weevil attack. These data suggest that increased (-)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka spruce after insect attack.

  13. Non-Target Plant Use by a Weed Biocontrol Agent in Idaho: Host Expansion or Opportunistic Behavior?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The weevil Larinus curtus Hochhuth (Coleoptera: Curculionidae) was first introduced into western United States from Greece for the biological control of yellow starthistle (YST), Centaurea solstitialis L. in 1992. Adults feed on YST pollen and flowers, laying eggs among flowers of YST capitula. Th...

  14. Determining radio frequency heating uniformity of mixed beans for disinfestation treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chickpeas and lentils are two important legumes grown in the US and need phytosanitary treatments before exportation, but it is difficult to artificially infest them with live cowpea weevil for radio frequency (RF) treatment validation. To evaluate the more readily infested black-eyed peas and mung ...

  15. Industrial-scale radio frequency treatments for insect control in lentils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Radio frequency (RF) treatments are considered to be a potential postharvest technology for disinfesting legumes of internal seed pests such as the cowpea weevil. After treatment protocols are shown to control postharvest insects without significant quality degradation, it is important to scale-up l...

  16. Development of artificial diet to rear internal-feeding insects to accelerate research on new biological control agents of yellow starthistle and other alien weeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We demonstrated that an artificial diet that was previously developed to rear the purple loosestrife root weevil, Hylobius transversovittatus, can be effective for completing the development of larvae that are dissected out of plants. We used this diet to rear to adult stage larvae and pupae of the...

  17. Determination of degree of infestation of triticale seed using NIR spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect infestation of seeds of the triticale hybrid, Triticosecale, causes extraordinary storage losses as a consequence of vulnerability of triticale seed to insect infestation and its soft coat. Rice weevil, Sitophilus oryzae (L.), is a common insect that causes infestation in Florida, which was t...

  18. First Report of Rhizoctonia spp. causing a root rot of the invasive rangeland weed Lepidium draba in North America.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The exotic, invasive perennial rangeland weed Lepidium draba spreads rapidly and reduces native species diversity. The extensive root system of L. draba constitutes 76% of plant biomass. Thus searches have been done for biocontrol agents that target root tissue or that may interact with a weevil, Ce...

  19. Laboratory virulence of entomopathogenic nematodes to two ornamental plant pests, Corythucha ciliata (Hemiptera: Tingidae) and Stethobaris nemesis (Coleoptera: Curculionidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study we evaluated the potential of entomopathogenic nematodes to control two important ornamental pests: 1) Corythucha ciliata, a native lace bug that attacks the foliage of sycamore trees, and 2) the recently described exotic pest, Stethobaris nemesis, a weevil that attacks amaryllis leave...

  20. Mitochondrial DNA Variation Among Populations of Rhynchophorus ferrugineus (Coleoptera: Curculionidae) From Pakistan.

    PubMed

    Yasin, Muhammad; Rugman-Jones, Paul F; Wakil, Waqas; Stouthamer, Richard

    2016-01-01

    The Red Palm Weevil (RPW) Rhynchophorus ferrugineus (Olivier) is a voracious pest of palm species. In recent decades its range has expanded greatly, particularly impacting the date palm industry in the Middle East. This has led to conjecture regarding the origins of invasive RPW populations. For example, in parts of the Middle East, RPW is commonly referred to as the "Pakistani weevil" in the belief that it originated there. We sought evidence to support or refute this belief. First reports of RPW in Pakistan were from the Punjab region in 1918, but it is unknown whether it is native or invasive there. We estimated genetic variation across five populations of RPW from two provinces of Pakistan, using sequences of the mitochondrial cytochrome oxidase subunit I gene. Four haplotypes were detected; two (H1 and H5) were abundant, accounting for 88% of specimens across the sampled populations, and were previously known from the Middle East. The remaining haplotypes (H51 and H52) were newly detected (in global terms) and there was no geographic overlap in their distribution within Pakistan. Levels of haplotype diversity were much lower than those previously recorded in accepted parts of the native range of RPW, suggesting that the weevil may be invasive in Pakistan. The affinity of Pakistani haplotypes to those reported from India (and the geographical proximity of the two countries), make the latter a likely "native" source. With regards the validity of the name "Pakistani weevil", we found little genetic evidence to justify it. PMID:27651423

  1. Acoustic detectability of Rhynchophorus cruentatus (Coleoptera: Dryophthoridae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The palmetto weevil, Rhynchophorus cruentatus Fabricius, native to Florida, attacks palm trees. Like its economically destructive relatives, R. ferrugineus (Olivier) and R. palmarum L., it feeds internally and often is not detected until irreparable damage occurs. Acoustic methods previously used su...

  2. Acoustic assessment of Beauveria bassiana (Hypocreales: Clavicipitaceae) effects on Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) larval activity and mortality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae), the red palm weevil, is an economically important palm tree pest in subtropical regions of the world. Previous studies have shown that R. ferrugineus can be infected and killed by the entomopathogenic fungus, Beauveria bassiana. Howev...

  3. Biological control of potato insect pest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of pest insects attack the potato crop and reduce yields. This book chapter reviews the known insect natural enemies for major potato pests around the world: Coleoptera (beetles) including Colorado potato beetle, 28-spotted lady beetle, and Andean potato weevil complex; potato tuber moths,...

  4. Taxonomic status of Trichosirocalus species (Curculionidae) attacking Carduus, Cirsium and Onopordum species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Trichosirocalus Colonnelli includes some host-specific weevil species or biotypes with a relatively narrow host-range limited to some thistles of the subfamily Carduinae. An Italian population of T. horridus (Panzer) was introduced in 1974 into the USA, and a population from Germany was in...

  5. Heterapoderopsis bicallosicollis (Coleoptera: Attelabidae): A Potential Biological Control Agent for Triadeca sebifera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Native to China, Chinese tallow, Triadica sebifera (L.) Small (Euphorbiaceae), is an invasive plant in the southeastern United States of America. The leaf-rolling weevil, Apoderus bicallosicollis Voss is a common herbivore attacking the plant in China. To evaluate its potential as a biological contr...

  6. Use of gamma radiation as a form of preservation of sweet potatoes. Quarterly progress report

    SciTech Connect

    Not Available

    1985-01-01

    This progress report covers: harvest and conditioning following harvest; effects of ..gamma.. radiation on the sweet potato weevil, organoleptic properties of sweet potatoes, protein content of same, and sweet potato quality (vitamins, color, texture, and carbohydrates). Evaluation of preliminary results indicate that changes should be made in irradiation procedures/conditions and analyses. (DLC)

  7. Potential of Heterorhabditis indica to control Cylas formicarius in field culled sweet potato roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweet potato weevil, Cylas formicarius, is one of the most destructive insect pests of sweet potato in Hawaii. The larvae feed and tunnel inside the root causing malformation and a bitter taste that makes the product unmarketable. During harvest, farmers leave off-grade roots in the field which se...

  8. Phenology and temperature-dependent development of Ceutorhynchus assimilis, a potential biological control agent for Lepidium draba

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heart-podded hoary cress (Lepidium draba) is an alien weed that has invaded rangeland in the northwestern USA. A host race (i;e; host-specific biotype) of the weevil, Ceutorhynchus assimilis, is being evaluated as a prospective biological control agent. This biotype is only known from southern Eur...

  9. 7 CFR 319.56-40 - Peppers from certain Central American countries.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... country for the weevil Faustinus ovatipennis, pea leafminer, tomato fruit borer, banana moth, lantana... site, the NPPO may not allow export from that production site until the NPPO has determined that risk... which Medfly is considered to exist: (1) The peppers must be grown in approved production...

  10. Large-scale confirmatory tests of a phytosanitary irradiation treatment against Sternochetus frigidus (F.) in Philippine mango

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mango pulp weevil, Sternochetus frigidus (F.) is an important quarantine pest preventing the export of mangoes from the Philippines to the United States and other countries. Previously, a radiation dose of 100 Gy was proposed for phytosanitary treatment of S. frigidus based on dose-response stud...

  11. Nonconstant Thermal Regimes Enhance Overwintering Success and Accelerate Diapause Development for Smicronyx fulvus (Coleoptera: Curculionidae).

    PubMed

    Prasifka, Jarrad R; Rinehart, Joseph P; Yocum, George D

    2015-08-01

    Recent populations of the red sunflower seed weevil, Smicronyx fulvus LeConte (Coleoptera: Curculionidae), have been inconsistent or declining, particularly in North Dakota. Consequently, research on weevil biology, including development of resistant germplasm, has been limited. To determine whether cold storage of diapausing larvae could be improved, nonconstant temperature treatments (fluctuating thermal regime [FTR] and thermoperiod [TP]) were tested versus a constant 6°C for storage up to 365 d. Both alternate temperature treatments produced more adult weevils than constant 6°C for short (42, 91 d) storage, while all temperature treatments were good (≥60% adult emergence) at moderate term (182 d) cold storage, and FTR was best for long (365 d) periods. Excluding the 14-d storage period, which produced too few weevils for comparison, each doubling of cold storage time (e.g., from 42 to 91 d, 91 to 182 d), usually decreased the number of days to 50% relative emergence by ∼10 d. After 365 d of larval storage, emerged S. fulvus adults successfully infested sunflowers in a plant growth chamber, with damage per female similar to that observed in field trials. Compared with previous efforts to store weevil larvae, the method of collection and FTR storage is either more effective (greater adult emergence and reduced parasitism) or more time-efficient, and should permit year-round research using S. fulvus adults. Because successful emergence under FTR was >75% after 365 d, additional research would be required to determine the maximum effective duration of cold storage for S. fulvus. PMID:26470322

  12. Habitats as complex odour environments: how does plant diversity affect herbivore and parasitoid orientation?

    PubMed

    Wäschke, Nicole; Hardge, Kristin; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2014-01-01

    Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts. PMID:24416354

  13. Effects of elevated temperature and CO2 on aboveground-belowground systems: a case study with plants, their mutualistic bacteria and root/shoot herbivores.

    PubMed

    Ryalls, James M W; Riegler, Markus; Moore, Ben D; Lopaticki, Goran; Johnson, Scott N

    2013-01-01

    Interactions between above- and belowground herbivores have been prominent in the field of aboveground-belowground ecology from the outset, although little is known about how climate change affects these organisms when they share the same plant. Additionally, the interactive effects of multiple factors associated with climate change such as elevated temperature (eT) and elevated atmospheric carbon dioxide (eCO2) are untested. We investigated how eT and eCO2 affected larval development of the lucerne weevil (Sitona discoideus) and colonization by the pea aphid (Acyrthosiphon pisum), on three cultivars of a common host plant, lucerne (Medicago sativa). Sitona discoideus larvae feed on root nodules housing N2-fixing rhizobial bacteria, allowing us to test the effects of eT and eCO2 across trophic levels. Moreover, we assessed the influence of these factors on plant growth. eT increased plant growth rate initially (6, 8 and 10 weeks after sowing), with cultivar "Sequel" achieving the greatest height. Inoculation with aphids, however, reduced plant growth at week 14. eT severely reduced root nodulation by 43%, whereas eCO2 promoted nodulation by 56%, but only at ambient temperatures. Weevil presence increased net root biomass and nodulation, by 31 and 45%, respectively, showing an overcompensatory plant growth response. Effects of eT and eCO2 on root nodulation were mirrored by weevil larval development; eT and eCO2 reduced and increased larval development, respectively. Contrary to expectations, aphid colonization was unaffected by eT or eCO2, but there was a near-significant 10% reduction in colonization rates on plants with weevils present belowground. The contrasting effects of eT and eCO2 on weevils potentially occurred through changes in root nodulation patterns.

  14. Host use and crop impacts of Oribius Marshall species (Coleoptera: Curculionidae) in Eastern Highlands Province, Papua New Guinea.

    PubMed

    Wesis, P; Niangu, B; Ero, M; Masamdu, R; Autai, M; Elmouttie, D; Clarke, A R

    2010-04-01

    Oribius species are small flightless weevils endemic to the island of New Guinea and far northern Cape York, Australia. The adults feed externally on leaves, developing fruit and green bark, but their impact as pests and general host use patterns are poorly known. Working in Eastern Highlands Province, Papua New Guinea, we carried out structured host use surveys, farmer surveys, shade-house growth trials and on-farm and on-station impact trials to: (i) estimate the host range of the local Oribius species; (ii) understand adult daily activity patterns; (iii) elucidate feeding habits of the soil dwelling larvae; and (iv) quantify the impacts of adult feeding damage. Oribius inimicus and O. destructor accounted for nearly all the Oribius species encountered locally, of these two O. inimicus was the most abundant. Weevils were collected from 31 of 33 plants surveyed in the Aiyura Valley, and a combination of farmer interviews and literature records provided evidence for the beetles being pestiferous on 43 crops currently or previously grown in the Highlands. Adult weevils had a distinct diurnal pattern of being in the upper plant canopy early in the morning and, to a lesser extent, again late in the afternoon. For the remainder of the day, beetles resided within the canopy, or possibly off the plant. Movement of adults between plants appeared frequent. Pot trials confirmed the larvae are root feeders. Quantified impact studies showed that the weevils are damaging to a range of vegetable and orchard crops (broccoli, capsicum, celery, French bean, Irish potato, lettuce, orange and strawberry), causing average yield losses of around 30-40%, but up to 100% on citrus. Oribius weevils pose a significant and, apparently, growing problem for Highland's agriculture. PMID:19366475

  15. Habitats as Complex Odour Environments: How Does Plant Diversity Affect Herbivore and Parasitoid Orientation?

    PubMed Central

    Wäschke, Nicole; Hardge, Kristin; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2014-01-01

    Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts. PMID:24416354

  16. The isotropic climatic records in the Alleroed-B{o}lling-Younger Dryas and post-Younger Dryas events

    SciTech Connect

    Epstein, S.

    1995-12-01

    This study compares isotope records of late glacial period climates from Greenland and Alaska. The isotopic composition of dated Alaskan wood samples was determined and compared to isotope data from the Greenland ice cap, pelagic foraminifera, and German pine trees. A time correspondence of large isotopic variations was observed, suggesting that the Allerod-Bolling and Younger Dryas events were widespread in the northern hemisphere, and not restricted to the North Atlantic region. In addition, data indicated that the Allerod-Bolling event was initiated by rapid cooling, and the Younger Dryas event by rapid warming in temperate zones. Consequently, isotopic oscillations recorded at Alaska and Greenland during the Glacial-Interglacial transition are not necessarily associated with temperature variations at those locations. 13 refs., 5 figs.

  17. Energy efficiency assessment methods and tools evaluation

    SciTech Connect

    McMordie, K.L.; Richman, E.E.; Keller, J.M.; Dixon, D.R.

    1994-08-01

    Many different methods of assessing the energy savings potential at federal installations, and identifying attractive projects for capital investment have been used by the different federal agencies. These methods range from high-level estimating tools to detailed design tools, both manual and software assisted. These methods have different purposes and provide results that are used for different parts of the project identification, and implementation process. Seven different assessment methods are evaluated in this study. These methods were selected by the program managers at the DoD Energy Policy Office, and DOE Federal Energy Management Program (FEMP). Each of the methods was applied to similar buildings at Bolling Air Force Base (AFB), unless it was inappropriate or the method was designed to make an installation-wide analysis, rather than focusing on particular buildings. Staff at Bolling AFB controlled the collection of data.

  18. The convergence problem of collocation solutions in the framework of the stochastic interpretation

    NASA Astrophysics Data System (ADS)

    Sansò, F.; Venuti, G.

    2011-01-01

    The problem of the convergence of the collocation solution to the true gravity field was defined long ago (Tscherning in Boll Geod Sci Affini 39:221-252, 1978) and some results were derived, in particular by Krarup (Boll Geod Sci Affini 40:225-240, 1981). The problem is taken up again in the context of the stochastic interpretation of collocation theory and some new results are derived, showing that, when the potential T can be really continued down to a Bjerhammar sphere, we have a quite general convergence property in the noiseless case. When noise is present in data, still reasonable convergence results hold true. "Democrito che 'l mondo a caso pone" "Democritus who made the world stochastic" Dante Alighieri, La Divina Commedia, Inferno, IV - 136

  19. Productivity potential and monetary evaluation of Bt cotton hybrids under varied agronomic manipulations in semi-arid conditions.

    PubMed

    Singh, Kulvir; Rathore, Pankaj; Gumber, R K

    2014-09-01

    Field experiments comprising three Btcotton hybrids in main, two plant geometries in sub and three nutrient levels in sub sub plots of Split Plot design replicated thrice were conducted at PAU, Regional Research Station, Faridkot during Kharif 2010 and 2011. MRC7361 recorded significantly the highest SCY (3121.6 kg ha(-1)) followed by Bioseed 6488 (2649.5 kg ha(-1)) and RCH134 (2107.4 kg ha(-1)). Statistically improved bolls per plant and boll weight primarily helped MRC7361 in achieving the highest yield. Owing to better fertilizer use efficiency (5.47) and water productivity (649.3 gm(-3)), highest net returns of < or = 101047 ha(-1) were observed with MRC7361 as compared to Bioseed 6488 (< or = 83343 ha(-1)) and RCH134 (< or = 63014 ha(-1)). Bolls per plant and benefit cost ratio was significantly enhanced under wider geometry of 67.5 x 90 cm. Application of 225 kg N, 45 kg P ha(-1) produced significantly higher SCY (2825.9 kg ha(-1)) owing to improved sympods and bolls per plant than 150 kg N, 30 kg P ha(-1) (2374.9 kg ha(-1)) and 187.5 kg N, 37.5 kg P ha(-1) (2677.6 kg ha(-1)). As a result of this, statistically highest net returns of < or = 89552 ha(-1) were obtained with application of 225 kg N, 45 kg Pha(-1). Water productivity improved significantly with each successive increase in the level of nutrients. Contrarily, fertilizer use efficiency exhibited reverse trend with statistically highest value (5.08) for the lowest level of nutrients. PMID:25204056

  20. JEF 2.2 Cross Section Library for the MCNP Monte Carlo Code.

    2003-11-24

    Version 01 This continuous energy cross-section data library for MCNP is based on the JEF-2.2 evaluated nuclear data library (ACE format). The present library was satisfactorily tested in thermal and fast criticality benchmarks. For analyses below 20 MeV, MCJEF22NEA.BOLlB was applied also in cell and core calculations dedicated to the study of the subcritical accelerator driven systems (ADS).