The influence of delayed mating on the reproduction of Ephestia cautella (Walker) (Lepidoptera: Phycitidae)

The influence of delayed mating on reproduction was studied for its possible value in the control of Ephestia cautella. When mating of both sexes was delayed for progressively longer periods, fecundity and fertility were both reduced correspondingly until no adult progeny were produced when mating was delayed for 8 days. Fecundity was also reduced where mating was delayed for females only. Female longevity increased from 6.8 days with no delay to 11.4 days with an 8-day delay. The period during which females could lay fertile eggs nevertheless was reduced from 5.4 days with no delay to 3.0 days with a 6-day delay. The number of eggs laid within 1 or 3 days after mating was also reduced as the delay was increased.Physiological causes of reduced fecundity in the female are discussed. Delayed mating induced by causes such as high background levels of sex pheromone is considered in relation to the control of E. cautella.