THE INFLUENCE OF AGGREGATION PHEROMONE ON WALKING BEHAVIOR OF COCKROACH MALES (BLATTELLA-GERMANICA L)

The walking behaviour of male cockroaches was analysed on a locomotion compensator. On this apparatus the animal moves freely over a spherical surface. The sphere revolves in such a way that the animal remains on top. When no orientational cues are presented the animals move in a non-orientating fashion, with characteristic walking periods interrupted by short stops, producing bimodal distributions for walking speed. There was no evidence of a particular searching strategy in any of the runs analysed. When a cockroach is given the opportunity of contacting a strip of filter paper impregnated with cockroach faecal extract, which stimulates aggregation in the free state, then it will walk towards this strip. The distance of the strip from the animal on the locomotion compensator is, however, held constant for each run. The shorter the distance, the slower the speed of walking and the longer the time period during which the animal remains standing. In the wild, this must contribute to the process of aggregation. The structures responsible for the observed responses in walking behaviour are probably antennal contact chemoreceptors.