Sex pheromone emission by female Stegobium paniceum (L.) (Coleoptera: Anobiidae) in relation to reproductive maturation and oviposition

Pheromone emission by female Stegobium paniceum (L.) was tested in the laboratory by measuring responses of males to filter paper discs that had been exposed to standardised air flow over females in a simple apparatus. Results indicated that although ether-extractable pheromone is present at eclosion, emission of pheromone is not appreciable until day 2 or 3 and does not reach a maximum until day 3 or 4. After mating, pheromone emission oscillates markedly for reasons not fully understood. Ovary maturation was monitored by dissection of females 0–5 days old; the first mature oocytes were found in the calyces on day 3. Synchrony between reproductive maturation and pheromone emission was thereby demonstrated. Copulatory behaviour and oviposition in relation to female mating history were studied. Virgin females produce a few infertile eggs during the latter part of their adult life; mated females produce far more, much earlier, but fecundity is reduced when a female is kept with another beetle, particularly a male. The significance of multiple mating was not ascertained since neither fecundity nor fertility was increased.