Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) To determine the economic impact of Lygus bugs on the new crops lesquerella and guayule; to evaluate the efficacy and selectivity of registered and experimental insecticides for the management of Lygus bugs on cotton, lesquerella, and guayule; to quantify the effect of biotic and abiotic factors on the flight behavior of Lygus bugs; and to quantify the movement of Lygus bugs from over-wintering habitats into cultivated crops and to measure intercrop dispersal of Lygus bugs during the growing season. Approach (from AD-416) Replicated plots experiments will be used to manipulate the density of Lygus bugs and measure effects on yield and quality of lesquerella and guayule. Replicated plots will be used to measure efficacy and selectivity of various current and new insecticides on Lygus bugs in cotton, lesquerella, and guayule. Tethered and free-flight chambers will be used to measure various parameters of flight behavior relative to temperature, light intensity, wind-speed, host plant, population density, and insect age and sex. Mass mark-recapture methods will be used to measure movement from over-wintering habitats and movement within and between lesquerella, guayule, cotton, and alfalfa. Documents Reimbursable with University of AZ.. 425 Log 30956. Lygus hesperus mating status had no effect on flight initiation or orientation to a vegetative cue and flight initiation of both sexes declined with wind speed. Females took a greater number of flights and flew greater total distances at 25C compared with 20C. Males flew less frequently and covered less distance than females. Studies at 30C and 16C are underway. L. hesperus adults and nymphs spend 28-32% of their time feeding on various plant structures. Adult feeding assays were completed on camelina and analyses are pending. Development times of L. hesperus were similar on alfalfa and lesquerella but longer on guayule and camelina. Survivorship was 73-85%, on most plants but dropped to 62% on camelina. Lesquerella is an excellent host while camelina is a poorer host. Feeding and oviposition choice tests showed that L. hesperus readily feed and oviposit on each plant species, but prefer vernonia>lesquerella>camelina. Field studies show that damage to fruiting structures are correlated with Lygus bug density but that damage to these structures leads to variable effects on yield and seed oil quantity. The final year of study also shows that timing of damage (early season vs. late season) is inconsequential. Overall, Lygus is not likely to be a limiting factor in lesquerella production. Lesquerella is, however, likely to be a sink for Lygus during the later winter and early spring and a source of Lygus in late spring. With alfalfa as a bridge crop, the growth of populations in lesquerella could influence dynamics in nearby cotton. Community analyses indicate that the new insecticides flonicamid and metaflumizone selectively suppress Lygus bug while having little impact on predaceous arthropods. Within-crop and intercrop movement of Lygus and associated natural enemies among cotton, alfalfa, guayule and lesquerella using multiple protein marks was quantified. Eleven mark-capture studies were completed over a two year period covering various stages of crop phenology. Insect samples have been assayed and data have been compiled for analysis. Mark- capture studies between strips of alfalfa planted within organic strawberry fields showed that the vast majority of Lygus remain in the alfalfa and very few dispersed more than 5.0-m into the surrounding strawberries. Further mark-capture field studies are quantifying Lygus and natural enemy dispersal patterns between the natural weed flora surrounding organic strawberry fields. All arthropod samples have been assayed and data are being compiled for analysis.
Impacts
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Progress 10/01/06 to 08/31/10
Outputs
Progress Report Objectives (from AD-416) To determine the economic impact of Lygus bugs on the new crops lesquerella and guayule; to evaluate the efficacy and selectivity of registered and experimental insecticides for the management of Lygus bugs on cotton, lesquerella, and guayule; to quantify the effect of biotic and abiotic factors on the flight behavior of Lygus bugs; and to quantify the movement of Lygus bugs from over-wintering habitats into cultivated crops and to measure intercrop dispersal of Lygus bugs during the growing season. Approach (from AD-416) Replicated plots experiments will be used to manipulate the density of Lygus bugs and measure effects on yield and quality of lesquerella and guayule. Replicated plots will be used to measure efficacy and selectivity of various current and new insecticides on Lygus bugs in cotton, lesquerella, and guayule. Tethered and free-flight chambers will be used to measure various parameters of flight behavior relative to temperature, light intensity, wind-speed, host plant, population density, and insect age and sex. Mass mark-recapture methods will be used to measure movement from over-wintering habitats and movement within and between lesquerella, guayule, cotton, and alfalfa. Agreement has ended; therefore, no additional progess has been made FY11.
Impacts
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) To determine the economic impact of Lygus bugs on the new crops lesquerella and guayule; to evaluate the efficacy and selectivity of registered and experimental insecticides for the management of Lygus bugs on cotton, lesquerella, and guayule; to quantify the effect of biotic and abiotic factors on the flight behavior of Lygus bugs; and to quantify the movement of Lygus bugs from over-wintering habitats into cultivated crops and to measure intercrop dispersal of Lygus bugs during the growing season. Approach (from AD-416) Replicated plots experiments will be used to manipulate the density of Lygus bugs and measure effects on yield and quality of lesquerella and guayule. Replicated plots will be used to measure efficacy and selectivity of various current and new insecticides on Lygus bugs in cotton, lesquerella, and guayule. Tethered and free-flight chambers will be used to measure various parameters of flight behavior relative to temperature, light intensity, wind-speed, host plant, population density, and insect age and sex. Mass mark-recapture methods will be used to measure movement from over-wintering habitats and movement within and between lesquerella, guayule, cotton, and alfalfa. Documents Reimbursable with University of AZ.. 425 Log 30956. Significant Activities that Support Special Target Populations Flight initiation and orientation behavior of Lygus bugs was studied in a vertical flight chamber. Mating status had no effect on flight initiation or orientation to a vegetative cue and flight initiation of both sexes declined with wind speed. Horizontal flight mill studies quantified flight behavior of Lygus bugs relative to temperature. Females took a greater number of flights and flew greater total distances at 25C (38 flights, 2445m) compared with 20C (14 flights, 382m). Males flew less frequently and covered less distance than females at 25C (24 flights, 593m) and 20C (4 flights, 9.2m).Observational studies quantified and characterized the feeding behavior of Lygus bugs on lesquerella and guayule. Insects spent 7-8% of their time probing and 29-32% feeding on various plant structures. The majority of time spent in feeding was on fruiting structures followed by feeding on stems, flowers, flower buds and leaves.Development and survival of Lygus bug was examined on lesquerella, guayule and alfalfa at 27C. Nymphal development times were similar on alfalfa and lesquerella (11 d) but slightly longer on guayule (12 d). Resulting adult females were largest on lesquerella and smallest on guayule. Male size was similar on alfalfa and lesquerella and smaller on guayule. Survivorship was similar on all plants, averaging 73-85%. Field studies over 3 years examined the potential impact of Lygus spp. on lesquerella yield and seed quality. Studies have shown that damage to flower buds and fruit are positively correlated with Lygus bug density and that damage to these structures led to negative correlations between yield and plant bug density in 1 yr, and between seed oil quantity and bug density in 2 yrs. Analyses of a 3rd year are pending.Community level analyses of data from large plot field studies indicate that two new insecticides, flonicamid and metaflumizone, selectively suppress Lygus bug and cotton flea hopper while having little or no impact on a wide diversity of predaceous arthropods that can contribute significant levels of suppression to other pests such as the sweetpotato whitefly. A 2 yr field study characterized and quantified within-crop and intercrop movement of Lygus spp. and associated natural enemies among cotton, alfalfa, guayule and lesquerella using multiple protein marking. Different proteins (soy milk, bovine skim milk, chicken egg whites) were applied to the centers of selected crops to mark resident arthropod populations and clear sticky traps were placed within and beyond the study site to collect Lygus and natural enemies 1, 4 and 7 days after marking. Eleven mark-capture studies were completed over 2 yr covering various stages of crop phenology. Insect samples have been assayed and data have been compiled for analysis. Similar dispersal studies using protein marking are being conducted in collaboration with colleagues at UC Davis, UC Santa Cruz, and Texas A&M University.Principal Investigators of the overall project met in Maricopa, AZ in June 2009 to discuss progress on specific objectives and to assess overall progress.
Impacts
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Progress 10/01/07 to 09/30/08
Outputs
Progress Report Objectives (from AD-416) To determine the economic impact of Lygus bugs on the new crops lesquerella and guayule; to evaluate the efficacy and selectivity of registered and experimental insecticides for the management of Lygus bugs on cotton, lesquerella, and guayule; to quantify the effect of biotic and abiotic factors on the flight behavior of Lygus bugs; and to quantify the movement of Lygus bugs from over-wintering habitats into cultivated crops and to measure intercrop dispersal of Lygus bugs during the growing season. Approach (from AD-416) Replicated plots experiments will be used to manipulate the density of Lygus bugs and measure effects on yield and quality of lesquerella and guayule. Replicated plots will be used to measure efficacy and selectivity of various current and new insecticides on Lygus bugs in cotton, lesquerella, and guayule. Tethered and free-flight chambers will be used to measure various parameters of flight behavior relative to temperature, light intensity, wind-speed, host plant, population density, and insect age and sex. Mass mark-recapture methods will be used to measure movement from over-wintering habitats and movement within and between lesquerella, guayule, cotton, and alfalfa. Documents Reimbursable with University of AZ.. 425 Log 30956. Significant Activities that Support Special Target Populations We completed the second year of a two year study aimed to characterize and quantify within-crop and intercrop movement of Lygus spp. and its associated natural enemies using a multiple protein mark-capture approach. We established adjacent fields of cotton, alfalfa, guayule and lesquerella within a 6.5 hectare field site. Different proteins (e.g. soy milk, bovine skim milk, chicken egg whites) were applied to the centers of selected crops to mark resident arthropod populations. Then, clear sticky traps at varying distances from these marked areas were established in each crop and outside the 6.5 hectare site. Lygus and natural enemies were collected from the sticky traps 1, 4 and 7 days after marking. A total of 11 separate mark-capture studies were completed over a two year period covering various stages of crop phenology. Insect samples are being assayed and data compiled for analysis. Similar lygus dispersal studies using the protein mark-capture approach are also being conducted in collaboration with colleagues at The University of California, Davis and at Texas A&M University. We initiated laboratory studies to examine the flight behavior of Lygus hesperus relative to age, host plant, light intensity and wind speed. A specialized flight assay system was constructed and refinements to the system and associated biosassays are underway. The selectivity of several candidate insecticides for control of Lygus hesperus were examined in replicated cotton field plots at the Maricopa Agricultural Center. Natural enemy and Lygus populations were monitored throughout the season and multivariate statistics were used to assess insecticide impact on the arthropod community. Two new insecticides, flonicamid and metaflumizone, were found to be selective and should be useful in natural enemy conservation programs in cotton and other systems were Lygus is a pest. A networking group was formed at the Entomological Society of America meeting in San Diego in December 2007 comprised of the investigators on this project. During a networking meeting, participants provided summaries of on-going activities and coordinated collaborative research projects. The group will continue to meet annually at ESA conferences in the future. Additional informal meetings of the USDA-ARS, Maricopa participants have been conducted periodically over the past year to discuss experimental design and coordinate execution of proposed studies.
Impacts
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) To determine the economic impact of Lygus bugs on the new crops lesquerella and guayule; to evaluate the efficacy and selectivity of registered and experimental insecticides for the management of Lygus bugs on cotton, lesquerella, and guayule; to quantify the effect of biotic and abiotic factors on the flight behavior of Lygus bugs; and to quantify the movement of Lygus bugs from over-wintering habitats into cultivated crops and to measure intercrop dispersal of Lygus bugs during the growing season. Approach (from AD-416) Replicated plots experiments will be used to manipulate the density of Lygus bugs and measure effects on yield and quality of lesquerella and guayule. Replicated plots will be used to measure efficacy and selectivity of various current and new insecticides on Lygus bugs in cotton, lesquerella, and guayule. Tethered and free-flight chambers will be used to measure various parameters of flight behavior relative to temperature, light intensity, wind-speed, host plant, population density, and insect age and sex. Mass mark-recapture methods will be used to measure movement from over-wintering habitats and movement within and between lesquerella, guayule, cotton, and alfalfa. Documents Reimbursable with University of AZ.. 425 Log 30956. Significant Activities that Support Special Target Populations The report serves to document research conducted under a reimbursable agreement with the University of Arizona. Additional details can be found in the report for CRIS 5347-22620-017-00D, Ecologically-Based Pest Management Strategies for Western Cotton. We initiated field studies to quantify the effect of Lygus spp. on the yield and quality of Lesquerella fendleri, a new industrial oil-seed crop being developed for desert production environments. A randomized block experiment with 4 levels of insecticide use intensity was established to manipulate the seasonal density of Lygus spp. We collected weekly insect sweep samples to monitor pest density, bi-weekly whole plant samples to monitor pest damage to buds, flowers and fruits, and end-of-season harvest samples to quantify yield and seed oil content. Data are currently being compiled and analyzed. We initiated field studies to document the arthropod fauna of guayule (Parthenium argenatum), a natural latex-producing plant, and L.fendleri with special emphasis on the seasonal dynamics and abundance of Lygus spp. and its associated natural enemies. Samples are currently being sorted and processed for analysis. We initiated field studies to characterize and quantify within-crop and intercrop movement of Lygus spp. and its associated natural enemies using a multiple protein mark-capture approach. We established adjacent fields of cotton, alfalfa, guayule and lesquerella within a 6.5 hectare field site. Different proteins (e.g. soymilk, bovine skim milk, chicken egg whites) were applied to the centers of selected crops to mark resident arthropod populations and clear sticky traps at varying distances from these marked areas were established in each crop and outside the 6.5 hectare site. Lygus and natural enemies were collected from the sticky traps 1, 4 and 7 days after marking. A total of six separate mark- capture studies were completed covering various stages of crop phenology. Insect samples are being assayed and data compiled for analysis. Similar lygus dispersal studies using the protein mark-capture approach are also being conducted in collaboration with colleagues at The University of California, Davis and at Texas A&M. We initiated laboratory studies to examine the flight behavior of Lygus hesperus relative to age, host plant, light intensity and wind speed. A specialized flight assay system is being constructed for data collection within the next 3 months. A four day symposium (2nd International Lygus Symposium) was held at the Asilomar conference center in Pacific Grove, CA 15-19 April during which all principal investigators of the overall project met to discuss research objectives and coordinate shared research projects. Abstract of the meeting and a capstone paper will be published later this year in Journal of Insect Science. Additional informal meetings of the USDA-ARS, Maricopa participants have been conducted periodically over the past year to discuss experimental design and coordinate execution of proposed studies.
Impacts
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