Attract to kill: Are Male German Cockroaches (Blattella germanica) Deterred by the Presence of Permethrin Pesticide; and if so, does the surface of application matter?

Abstract

Blattella germanica are unsanitary pests that are prolific in human-inhabited areas such as households, hospitals, and commercial kitchens. Pyrethroid pesticides have been used to manage cockroach infestations for decades, and while studies have shown that B. germanica populations can evolve resistance to pyrethroid exposure, few studies have determined whether they can also evolve behaviors for avoiding exposure to these pesticides. Therefore, our group aimed to study whether male B. germanica were deterred by the pesticide and if so, whether the surface of application of the pesticide mattered through two-choice bioassays. Through the 2 experiments, we tested whether the scent of a 0.35% permethrin pesticide affected the attractiveness of rye bread baits to male B. germanica. Our team hypothesized that there would be no significant difference between the groups treated with pesticides compared to those with no pesticide and that changing the surface of application to the bread bait will not reduce this deterrence. Traps containing filter paper treated with pesticide and placed adjacent to rye bread baits caught significantly less B. germanica than traps containing untreated filter paper. However, there was no significant difference between treated and untreated bread baits.  Our findings suggest that when a pesticide is mixed with an attractant, the deterrence B. germanica have to the pesticide decreases, which can help create new and more efficient ways of managing infestation.