The response of German cockroaches to commercial toxic baits and their potential to develop resistance

Multiple strains of German cockroaches, Blattella germanica, were exposed to four different toxic baits. The baits used were Roach Ender, Whitmire gel bait (not commercially available), Stapleton’s Magnetic Roach Food and Baygon. For each bait, strains varied in respect to bait consumption, percent bait eaten and mortality. Selection experiments were carried out to determine the potential for the development of resistance. After three generations of selection, incipient development of behavioral resistance was found in the Jacksonville and Puerto Rico strains exposed to Roach Ender. All strains exposed to Stapleton’s Magnetic Roach Food developed strong behavioral resistance. Video recordings were carried out to study the behavior of the selected strain and the stock of some strains that had developed behavioral resistance. The results from these experiments were inconclusive.