2011 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.
Pest management programs that include trapping as well as inspections are critical to implementing the methyl bromide alternatives for flour mills and food processing plants envisioned by the National Program Action Plan. The alternatives include integrated pest management (IPM) and alternative fumigants, which would be applied as needed rather than on a calendar basis. Effective pest monitoring is critical to the success of such systems, because monitoring provides necessary guidance for timing and targeting pest control applications. The sawtoothed grain beetle Oryzaephilus surinamensis infests a wide variety of food products and is an important pest in food processing plants. An effective chemical attractant for luring this pest into traps is needed as a component of monitoring systems. We have initiated experiments to identify, synthesize, and test attractants for these beetles by evaluating possible attractants produced by the beetles themselves. Females feeding on a diet of rolled oats were no more attractive than the oats alone, but males feeding on the same diet were significantly more attractive than the diet itself. We were able to collect the chemicals responsible for the attractiveness of the males and have started the process of evaluating the important individual chemicals in volatiles collected from the beetles. We have been using behavioral tests of attractancy to determine the chemistry of the attractive elements in volatile collections. Thus far, two fractions have been found to be responsible for most of the attraction. Experiments are now being conducted to determine the chemical composition of the attractive elements. We also examined a commercially available sawtoothed grain beetle lure and found that the lure is attractive, but not as attractive as the compounds collected from male sawtoothed grain beetles. This indicates that the effectiveness of current lures can be improved and thus enable traps to detect beetle populations at lower thresholds.
Duehl, A.J., Arbogast, R.T., Teal, P.E. 2011. Density-related Volatile emissions and responses in the red flour beetle, Tribolium castaneum. Journal of Chemical Ecology. 37:525-532.
Duehl, A.J., Arbogast, R.T., Teal, P.E. 2011. Age and sex related responsiveness of Tribolium castaneum (Coleoptera: Tenebrionidae) in novel behavioral bioassays. Environmental Entomology. 40(1):82-87.