The Use of Genetic Mechanisms and Behavioral Characteristics to Control Natural Populations of the German Cockroach.
Annual rept. no. 5,
VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF ENTOMOLOGY
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The summer work on an inactive ship made it possible to study population growth, behavior, and response to an insecticide treatment of German cockroaches under non-laboratory conditions. Studies have revealed differences in behavior according to age class, sex, and reproductive stage of adult females. Major features of these findings are summarized below. Small nymphs instars 1 and 2 aggregate intensely. They rarely move far from their harborage. They are generally under-represented in traps near infested harborages. Large numbers of small nymphs outside-of-harborage is a sign of stress. Adult males were characterized by random within-harborage distribution. They showed little or nor response to chemical stimuli that promoted aggregation or that had repellent effects presumably aggregation pheromone and repellent associated with high female density. They showed least survivorship of all age classes in a treatment aimed at partial kill. Adult females shoe complex behaviors. They are producers of chemical stimuli that affect within-harborage distribution and that may trigger away-from-harborage movement. The shipboard studies showed that infested harborages tended to remain inhabited even if space was limited or foodwater removed to a more distant location.