Aspects of Mating Frequency and Reproductive Maturity in Papilio zelicaon

Abstract

Female P. zelicaon in different populations show a mean frequency of 1.2-1.9 matings, with a maximum of 3. Mating frequency increases with female age. No seasonal or latitudinal mating frequency differences were discovered but mating frequency was significantly greater in females from montane populations compared to lowland females. This difference was interpreted as resulting from increased mating frequency of selected males in hilltop areas leading to sperm accessory gland depletion and rapid return of sexual receptivity in females mated to such males. Use of sperm from the last male in a mating sequence (sperm displacement) occurred in a double-mated female using a red-eyed mutant as a genetic marker. hemales mated to mature males laid more ova than those paired with immature males, while no differences were noted between the latter group and virgin females. Oviposition appears to be influenced more by sperm quantity and/or accessory gland secretion than by physical presence of the spermatophore. Rapid multiple mating by males leads to smaller spermatophores deficient in sperm. Sperm is produced continuously at a uniform rate during the male''s life whereas production rate of accessory gland secretions decreases with male age. At least 40-50% of males less than 12 h old are incapble of insemination of females. Male mating ability (related to variance and duration of copulation) is low from 0-12 h, peaks at age 2-8 days, then gradually declines. Extended copulation occurred in immature and old males and in second matings of rapid mating sequences. This was regarded as permitting sperm/accessory fluids to be produced and transferred in copulo while allowing depleted or immature males to exploit mating opportunities.