Toxicity of Imidacloprid through Multiple Routes of Exposure to Jalysus wickhami (Hemiptera: Berytidae)

Neonicotinoid insecticides, prominently imidacloprid (Admire Pro), are important for the management of early season tobacco pests. These insecticides are xylem mobile and applied systemically in transplant water treatments. Key caterpillar pests including Heliothis virescens (Fabricius) and Manduca sexta (L.), are unaffected by these insecticides, but their abundance may be affected by hemipteran predators including the Jalysus wickhami (Say). This hemipteran insect has piercing-sucking mouthparts and feeds occasionally on the plant, potentially exposing itself to systemically applied insecticides. Previous work has documented that budworm survival is higher, and parasitism by parasitic wasps is lower,in tobacco treated with imidacloprid, and that imidacloprid moves from tobacco, to the caterpillar, to parasitic wasp larvae inhabiting the caterpillar. While the effects of imidacloprid on caterpillar parasitism are coming into focus, its impact on hemipteran predators is unclear. Thus, the goal of this research is to assess the impact of imidacloprid on Jalysus wickhami in tobacco and develop management strategies in which insecticide applications and biological control are harmonized.

A series of laboratory experiments were performed with Jalysus wickhami to determine the toxicity of imdiacloprid via multiple routes of exposure. Adult and nymph Jalysus wickhami were exposed to imdiacloprid via contact, systemic, and topical routes of exposure.