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Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/29/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Previous research had demonstrated that immature stages (4th to 6th instar nymphs) of the German cockroach were more tolerant of insecticides than adult males. For the insecticide propoxur, this enhanced tolerance was attributed to greater detoxification enzyme quantity in nymphs as compared with adult males. A scientist at the U.S. Department of Agriculture, Agricultural Research Service, Center for Medical, Agricultural and Veterinary Entomology, in Gainesville, Florida, confirmed those results. Nymphs were 20 times more tolerant to the insecticide, bendiocarb, than were adult males. Nymphs were made as susceptible as adult males to bendiocarb with the addition of the insecticide synergist, piperonyl butoxide. Apparently, the higher detoxification rate of nymphs protects them against an array of insecticides. An increased understanding of the way in which nymphs cope with insecticide exposure may lead to more effective control measures for German cockroach populations. Technical Abstract: Last instar nymphs of the Village Green strain of German cockroach were 20-fold more tolerant to topically applied bendiocarb than adult males. Pretreatment with the microsomal monooxygenase inhibitor, piperonyl butoxide, eliminated this difference. The synergist bioassay results suggest that nymphs may possess an enhanced oxidative enzyme capability which is responsible for the differential bendiocarb tolerance. |
