Performance of cockroach gel baits against susceptible and bait averse strains of German cockroach, Blattella germanica (Dictyoptera: Blattellidae) - role of bait base and active ingredient.

Three experimental gel matrices containing indoxacarb and three market-leading Maxforce gels containing either fipronil or hydramethylnon were evaluated and the roles of active ingredients and bait bases in the bait performance were examined against both lab susceptible and bait averse strains of German cockroach, Blattella germanica. For lab susceptible Orlando cockroaches, most cockroach gel baits performed very well regardless of the type of active ingredients or bait bases. For bait averse Miami cockroaches, bait matrices turned out to be the determining factor for control. For currently available products, both the Maxforce FC gel containing fipronil and Maxforce gel containing hydramethylnon were not efficacious, but Maxforce FC Select gel with fipronil showed excellent efficacy against Miami cockroaches. For the experimental gels, even the newly-developed bait base, which had never been introduced into the field, was subject to bait aversion problems. Still, indoxacarb gel baits using the best of three matrices (Advion-C) showed excellent efficacy against both susceptible and bait averse cockroaches.