2013 Annual Report
1a.Objectives (from AD-416):
To study, through both laboratory and field investigation, the physiology, biochemistry, biology, ecology, and control plant bugs on various host crops in the arid southwestern USA with the goal of developing environmentally sound and sustainable pest management strategies.
1b.Approach (from AD-416):
Laboratory studies will focus on elucidating the feeding physiology and biochemistry of plant bugs feeding on cotton and other hosts. Specific biochemical pathways will be determined and evaluated and molecular methods will be used to identify potential genetic based methods for disrupting these pathways (e.g. RNAi). The life history of plant bugs on new industrial crops will be quantified under controlled conditions. The potential impact of plant bugs on yield and quality of new industrial crops will be investigated in the greenhouse and field using inclusion cages and field manipulation of plant bug populations. Documents SCA with U of AZ.Formerly 5347-22620-020-03S (11/10).
This is the final report for 5347-22620-021-03S. Additional details for the research can be found in the report for the parent project 5347-22620-021-00D, Sustainable Pest Management Strategies for Arid-land Crops. This Special Cooperative Agreement is in support of Objective 3, "Characterize flight behavior and dispersal of insect pests and natural enemies; elucidate relationships among landscape structure, pest and natural enemy biology and dispersal behavior", Subobjectives 3.1, "Characterize the flight behavior of Lygus hesperus relative to environmental factors", 3.2, "Quantify within and between crop movement of L. hesperus", and, 3.3, "Quantify crop source-sink relationships for arthropod predators inhabiting cotton within the agroecosystem", and of Objective 5, "Refine insecticide-based management strategies; characterize factors influencing resistance to chemical insecticides and insecticidal proteins in transgenic crops; evaluate insecticide selectivity; support post-eradication pink bollworm resistance monitoring in Bt cotton", and, Subobjective 5.1, "Evaluate insecticide selectivity in the cotton system". Flight assays were conducted to compare flight performance of Lygus bugs when they had been reared and fed on guayule, alfalfa or an established artificial diet at 25C. Those feeding on the artificial diet were the most active followed by those reared on alfalfa and then guayule (both with flowers, flower buds). Adults reared on plant diets had comparatively higher rates of mortality compared with those reared on diets and females failed to mature reproductively. The influence of diapause status on flight behavior was also examined. There was no difference in resting metabolic rate or flight activity between diapausers and non-diapausers, however, there were significant gender differences. Males had higher resting metabolisms than females, whereas females spent more time flying. Spatial analyses of Lygus bugs and associated natural enemies at the landscape level are continuing on data from Arizona and California. Issues with some of the Arizona crop maps are being resolved and data are being formatted for analyses. Protein marking is being used to examine the within field movement of Lygus in cotton. In situ populations were marked with either egg or milk proteins in central plots and then recaptured up to 72 hours later in plots surrounding the central release area. Unusually high levels of rainfall interfered with the first 2 trials of the study and there was a low level of recapture in the third trial. The study is being repeated this summer using a new sampling method where we hope to boost recapture rates. Lygus management demonstration projects were continued in grower fields in Arizona and Mexicali. Guidelines were disseminated to growers via Extension circulars, advisories, in-field workshops, and presentations to growers including Mexicali, Mexico.