Monday, December 11, 2006 - 8:59 AM

Mating and dispersal behavior of the western corn rootworm Diabrotica virgifera virgifera (LeConte) in Bt cornfields

Paul T. Marquardt, and Christian H. Krupke, Purdue University, Entomology, 901 West State St, West Lafayette, IN


A clearer understanding of the mating and dispersal behavior of the Western corn rootworm, Diabrotica virgifera virgifera (LeConte), is essential to help predict potential resistance to transgenic corn technologies (B.t. corn) deployed to combat this pest. Field research was conducted in the summer of 2006 to determine how far newly emerged female beetles move before mating occurs and the time of day of this initial mating. Newly-emerged females were examined from the time of emergence for up to 4 hours or until mating occurred. Preliminary data indicate that female beetles do not move a significant distance from the site of emergence before mating. In order to quantify movement of male beetles, complementary studies were conducted in commercial transgenic cornfields that included the EPA-mandated 20% refuge acreage.  Wing traps containing a single virgin female beetle were placed in the transgenic area of the field, at known distances from the nearest refuge and vice versa. Male beetles were collected from the sticky bottoms of traps and had their gut contents assayed with protein test strips to determine whether the B.t. protein was present. This provided an estimate of the distances traveled by males to reach virgin females. The implications of these data for movement and mating patterns of adult rootworms in B.t./refuge environments are discussed.

Species 1: Coleoptera Chrysomelidae Diabrotica virgifera virgifera (western corn rootworm)

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