The Physiological Basis for the Termination of Pheromone-releasing Behaviour in the Female Brown-banded Cockroach, Supella Longipalpa (f.) (dictyoptera: Blattellidae)

The factors contributing to the termination of calling (pheromone release) in adult female Supellu longipalpa were examined. Calling ceases after mating and does not resume over the duration of the insect’s life. Calling was suppressed and basal oiicyte growth was stimulated by the transient presence of a sperrnatophore, by the implantation of an artificial spermatophore, and by mating with vasectomized males. Calling resumed after odthecal deposition in females mated with vasectomized males. Ventral nerve cord transections, either immediately following copulation or after odthecal deposition, restored calling in mated females. The experimental evidence suggests that the termination of calling is mediated neurally by a two-stage process, initiated by placement of the spermatophore in the bursa copulatrix and maintained by the presence of sperm in the spermatheca. Key Word Index: Supella longipalpa; calling behaviour; mating behaviour; spermatophore; spermatheca; nerve transection; pheromone release