2012 Annual Report
1a.Objectives (from AD-416):
Develop improved methods for monitoring efficacy of control of stored product insect pests resulting from use of alternatives to the use of methyl bromide as structural fumigants in stored product facilities and provide improved methods population monitoring and for integrated pest management in food facilities such as wheat flour mills, rice mills, pet food facilities, and associated warehouses with the goal of eliminating the need for use of methyl bromide as a fumigant in these facilities.
1b.Approach (from AD-416):
Biological assay guided fractionation of naturally produced chemicals collected using various techniques will be used. Chemicals will be identified by chromatographic, spectroscopic and microdegradative methods and synthesized using organic synthesis procedures. Synthetic samples will be formulated using physicochemical principals so as to release ratios and amounts of chemicals identical to those released by natural sources and tested in biological assays.
One element of successfully replacing methyl bromide fumigation is spraying insecticides at times and locations where and when insects are most numerous. We observed daily patterns in red flour beetle behavior that had not been previously described. The patterns included both where they aggregated and when they tried to disperse. By taking pictures of colonies over the course of the day and quantifying the flour surface area covered by beetles we were able to show optimum spray times that would contact the most beetles. We also examined how beetles responded to changing light conditions and showed that light cycles were responsible for the observed patterns.
To improve detection of stored product insect infestations detecting dispersing individuals at low numbers will find infestations before they grow larger. By examining behavior relative to dispersal in colonies we showed that aggregation locations in rearing containers were based on clean air and different odor cues not true aggregation behavior. In fact odors that were ordinarily repellent or not particularly responded to were attractive to beetles attempting to disperse from enclosed spaces. Based on these patterns of dispersal, beetles moving from high density likely use odor cues to disperse and look for different and clean air cues before searching for food or mates. With these aggregation and dispersal cues trapping locations and treatment times will be improved.
We have a paper in preparation reporting these results.
New trapping system developed for stored product beetles. Studies of several species beetle pests of stored grains showed that all are preferentially attracted to light at 390nm. Additionally, a new trap was designed that takes advantage of the behavior of the beetles to climb edges. Warehouse trials demonstrated that the new trap was more than 20 times better than commercially used traps in capturing beetles. Development of this new trapping system significantly improves the ability to monitor for stored product pests even when pests are present at extremely low levels. The system promises to significantly reduce pesticide use for control of these pests because instead of whole mill or warehouse fumigation only specific areas need now be treated.
Cohnstaedt, L.W., Rochon, K., Duehl, A.J., Anderson, J., Barrera, R., Su, N., Gerry, A., Obenauer, P., Campbell, J.F., Lysyk, T., Allan, S.A. 2012. Arthropod surveillance programs: Basic components, strategies, and analysis. Annals of the Entomological Society of America. 105:135-149.
Duehl, A.J., Cohnstaedt, L.W., Arbogast, R.T., Teal, P.E. 2011. Evaluating light attraction to increase trap efficiency for Tribolium castaneum (Coleoptera: Tenebrionidae). Journal of Economic Entomology. 104(4):1430-1435.