University Of California Riverside Reitred Entiomology Profe Riverside, California
Baits have become one of the most common formulations for the control of German cockroaches. Baits are composed of active ingredient(s) (insecticide), food base, attractants and feeding stimulants, as well as preservatives. Baits may be formulated as granules, dry deposits, gels, dusts, and pastes. Each bait formulation has unique rheology which may affect feeding. Some baits may be enclosed in child- and pet-resistant stations. Active ingredients of successful baits are typically non-repellent, active at low concentrations, and relatively slow-acting. Factors that affect bait consumption include cockroach biology and feeding behavior, placement and availability of bait deposits, palatability, contamination, and physiological and behavioral resistance. Horizontal transfer or secondary kill can occur when active ingredients are passed among individuals within a population. This can occur through simple contact or by consumption of insecticide-contaminated excretions or cadaviers. Coprophagy (consumption of feces), emetophagy (consumption of vomitus or regurgitated material) and cannibalism (predation on live conspecifics or consumption of cadavers or necrophagy) can facilitate transfer of insecticide among individuals.
Bait performance in the field is affected by an insufficient amount bait and an insufficient number of bait placements. Resistance to active ingredients or feeding stimulants (bait aversion) also reduces bait performance. Rotation or mixtures of bait active ingredients as well as attractants and feeding stimulants may help avoid or delay resistance.
