Insect pests, including the German cockroach, Blattella germanica (L.), are prone to the development of physiological resistance when exposed to a number of insecticide sprays, and cross-resistance is frequently observed. Toxic baits are often used as a primary method of controlling German cockroaches, also resulting in heavy selection pressure from insecticidal baits. In response to this pressure, cockroach populations have developed aversion to specific inert ingredients in bait. Here, we examined the effect of exposure to baits containing fipronil, indoxacarb, or hydramethylnon on the development of physiological resistance to the same and other insecticides in a number of German cockroach strains. We found that prolonged exposure to baits containing fipronil or indoxacarb increased physiological resistance to these compounds. However, no increase in physiological resistance against any insecticide was observed in response to exposure to hydramethylnon bait. Additionally, we found that exposure to fipronil bait increased cross-resistance to indoxacarb. On the other hand, exposure to indoxacarb bait did not increase cross-resistance to fipronil. Neither fipronil nor indoxacarb bait exposure increased resistance to hydramethylnon. Interestingly, the development of insecticide resistance in response to bait exposure was strain-dependent and influenced by bait palatability. Our results demonstrate that exposure to toxic baits, particularly those containing fipronil, plays a significant role in the development of insecticide resistance, including cross-resistance, in German cockroaches. Further, although insecticide resistance in response to baits is mediated by exposure through the oral route, the molecular mechanisms at play are likely different for each insecticide.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 110 • No. 4