Journal of Economic Entomology (1994) 87, 885-893

Mark E. Hostetler and Richard J. Brenner (1994)
Behavioral and physiological resistance to insecticides in the German cockroach (Dictyoptera: Blattellidae): An experimental reevaluation
Journal of Economic Entomology 87 (4), 885-893
Abstract: Although physiological resistance to pesticides has been demonstrated in German cockroaches, Blattella germanica (L.), behavioral resistance has not been shown clearly. To test for the possible development of behavioral resistance, choice-test experiments were done to determine whether adult males and females from physiologically resistant and susceptible strains differed in avoidance of three emulsifiable formulations (chlorpyrifos, cypermethrin, and chlordane). Physiological resistance was verified by estimation of LC₅₀s. Within 6 h, each cockroach chose between an untreated and a treated harborage. In the resistant strain, both sexes avoided harborages treated with cypermethrin and survived the choice tests, but more females than males avoided harborages treated with chlorpyrifos and survived. In the susceptible strain, neither sex avoided harborages treated with cypermethrin or chlorpyrifos, and most died. The physiologically resistant strain was more resistant to chlorpyrifos and cypermethrin than was the susceptible strain, with females generally having higher LC₅₀s. However, in choice tests with chlordane in which physiological resistance levels were similar between the strains, the strains did not differ in avoidance of treated harborages or survivorship. Avoidance of treated harborages may be facilitated by high levels of physiological resistance, but we detected no behavioral resistance traits. High levels of physiological resistance permitted cockroaches to absorb an amount of pesticide that led to detection and subsequent avoidance of treated harborages. Results of our study suggest that previous research on insects has not demonstrated the evolution of stimulus-dependent behavioral resistance infield populations exposed to pesticides.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Blattella germanica