MATING-INDUCED LOSS OF SEX-PHEROMONE AND SEXUAL RECEPTIVITY IN INSECTS WITH EMPHASIS ON HELICOVERPA-ZEA AND LYMANTRIA-DISPAR

Mating in most species of insects leads to a transient or permanent lo ss in sexual receptivity of the females. Among moths, this loss of rec eptivity is often accompanied with a loss of the sex pheromone in the absence of calling, which also could be temporary or permanent. Most o f the earlier work on changes in reproductive behavior after mating wa s done with Diptera in which sperm and/or male accessory gland secreti ons were shown to be responsible for termination of receptivity. In th e corn earworm moth, Helicoverpa tea, mated females become depleted of pheromone and become nonreceptive to further mating attempts, but onl y for the remainder of the night of mating. A pheromonostatic peptide isolated from the accessory glands of males may be responsible for the depletion of pheromone, while the termination of receptivity is indep endently controlled. In the gypsy moth, Lymantria dispar, the changes in behavior following mating are permanent. In this species, the switc h from virgin to mated behavior involves three steps: a physical stimu lation associated with mating, transfer of viable sperm to the spermat heca, and commencement of oviposition. Signals generated by these fact ors operate through neural pathways and, unlike in H. tea, accessory g land factors seem not to be involved. (C) 1994 Wiley-Liss, Inc.