Taking the bait: intercepting cucurbit pests using kairomonial semiochemicals for use in narrow spectrum biorational management

Insect pest management in cucurbit crop systems is a major challenge to organic growers due to the short residual time, questionable efficacy and expense of many approved chemicals. Conventional growers face controversies surrounding the use of chemicals such as imidacloprid, in regard to pollinator safety. A study to examine the potential of a perimeter trap-cropping regime based on using imidacloprid treated plant seedlings contained by plastic barriers was conducted in central Kentucky. This potential strategy could alleviate many concerns surrounding conventional trap-cropping that utilizes systemic insecticides. By using young, non-flowering plants, this method could help reduce the exposure risk to pollinating insects and, because the plants are contained and applications are not made directly to crops, consideration in certified organic production may be possible. While pilot results show promise, further concerns surround the system. Preliminary discussions with organic growers in Kentucky highlighted two primary concerns, namely: that beetles could consume the treated material and then die in certified fields, thus leading to contamination, and that the presence of synthetic chemicals on the farm altogether would not fit into their organic management plans. To address the first concern, a laboratory experiment was conducted to investigate if and/or how much treated plant material must be consumed to generate lethal effects in Acalymma vittatum. The possibility of combining applications of cucurbitacins, gustatory stimulants for cucumber beetles, with applications of spinosad, an approved organic insecticide, to seedling plants was investigated at a field site in southeastern Ohio.