Colorado potato beetle movement in Wisconsin potato cropping systems: Development of an area-wide management program

The Colorado potato beetle, Leptinotarsa decemlineata (Say), is the most damaging pest of potatoes in North America. Studies were conducted form 1996 to 1999 to: (1) test the deployment of a trap crop treated with systemic insecticides to delay Colorado potato beetle infestation into fields in the spring; and (2) to develop an area-wide Colorado potato beetle pest management program for commercial Wisconsin potato growers.; Eighteen field edges in Central Wisconsin were sampled in 1996 to determine the feasibility and efficacy of the deployment of systemic imidacloprid (Admire RTM) on field edges to reduce the movement of Colorado potato beetle adults into fields in spring. Whole field treatments of AdmireRTM were extremely effective in providing season-long Colorado potato beetle control. AdmireRTM-treated trap crop areas protected treated edges from defoliation but were not sufficiently toxic to dispersing adults to limit Colorado potato beetle infestations into the main crop area.; A geographic area of greater then 45,000 acres of land in southern Portage County, Wisconsin was designated as an experimental area for area-wide pest management of the Colorado potato beetle. During a three year period (1997 to 1999) beetle populations in each potato field within this region (122 fields) were determined by field sampling and mapped using GIS computer systems. The distance between current and previous potato fields in a rotation and the style of beetle management were the primary factors affecting distribution within the area. Long distance rotations of greater than 400 meters were an effective cultural control management strategy to limit adult beetle infestations in the spring. The insecticidal management strategy used also aided in the reduction of Colorado potato beetles leaving fields in the fall and entering fields in the spring. Area-wide Colorado potato beetle management can be an effective resistance management strategy. Alternations of chemical classes in adjacent fields can reduce the selection pressure on the Colorado potato beetle by particular insecticides, thus delaying the onset of resistance.