Toxicity, Repellence, and Effects of Starvation Compared Among Insecticidal Baits in the Laboratory for Control of American and Smokybrown Cockroaches (Dictyoptera: Blattidae)

Commercial formulations of insecticidal baits were evaluated in laboratory studies against the American cockroach, Periplaneta americana (L.), and the smokybrown cockroach, P. fuliginosa (Serveille). Continuous exposure toxicity tests and Ebeling choice box tests showed that these cockroach species are killed rapidly by most of the tested baits. For American cockroaches in choice boxes, the order of bait toxicity was GOLD CREST (chlorpyrifos) 18 d) consumed more than their own dry mass after 48 h exposure to several baits. Both species differed in initial percentage of body fat, but as period of starvation increased, percentage of fat decreased. Values of R, the correlation coefficient, suggested that percentage of fat might be a better indicator of the amount of bait eaten compared with the period of starvation ( R = -0.86 and 0.82, respectively). GOLD CREST bait was eaten significantly less than dog food (the experimental control) by American cockroaches, and MAXFORCE was eaten significantly less than dog food by smokybrown cockroaches.