Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 7, 2010
Publication Date: February 15, 2011
Citation: 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. Interpretive Summary: The red flour beetle Tribolium castaneum is a major pest of flour mills and other food processing facilities that has traditionally been controlled by periodic fumigation with methyl bromide. However, the pending loss of methyl bromide mandated by the Montreal Protocol on Substances that Deplete the Ozone Layer has made it necessary to seek alternative pest management strategies based on improved sanitation and alternative fumigants or other insecticides, as well as non-chemical methods, applied as needed rather than on a calendar schedule. Such pest management strategies will require better methods of monitoring to detect infestation and guide the application of pest control measures. Scientists at the Center for Medical, Agricultural and Veterinary Entomology, ARS, USDA in Gainesville, FL, are researching better chemical attractants and traps to be used for this purpose. They have developed new bioassay techniques that are essential to study the responses of this insect to various stimuli and thus determine the effectiveness of monitoring methods. These new bioassay techniques will benefit other scientists working on management of stored product insect pests, and ultimately they will benefit the milling and other food processing industries.
Technical Abstract: The hardiness and mobile nature of Tribolium castaneum (Herbst) make them easy to work with but are the same factors that make their responses to behavior modifying chemical stimuli difficult to evaluate. To overcome these difficulties we developed two bioassays: a two choice test with airflow and a diffusion-based test to evaluate responses to chemical stimuli. The two choice assay is excellent for rapidly comparing two stimuli or examining the response to one stimulus against a control. The diffusion assay determines differences in attraction to multiple simultaneous stimuli and can examine other behaviors during exposure. Preparation of individuals for bioassay is also important, because disturbance increases the traversal speed of individual beetles and this change continues after the disturbance ends. The age and sex of beetles affect responsiveness to chemical cues. These bioassays and a better understanding of T. castaneum’s activity have revealed approaches for evaluating its responsiveness to behavior modifying chemicals.