Diet experience and German cockroach bait performance

Baits are largely effective for controlling the German cockroach, Blattella germanica.  However, bait performance may depend on how the formulation competes within a complex nutritional milieu. 

I formulated diets of varying macronutrient (protein and carbohydrate) composition with and without toxicant, and pre-exposed insects to the non-toxic diet for 7 days prior to adding toxic diet.  I show that German cockroach mortality was highest when high protein non-toxic diets were followed by high carbohydrate toxic diets.  Thus, German cockroach nutritional condition affects bait performance and that baits closely matching the insect’s intake target may be optimal.