Fecundity, Egg Fertility, Duration of Oviposition, and Longevity of Alfalfa Weevils1 from Eight Mating and Storage Conditions

Abstract

Ilypera postica (Gyllenhal) females each exposed to a male for 24 consecutive hours per week laid significantly more eggs than isolated once-mated females. Females each kept constantly with a male laid no more eggs than once-mated females, because the male offsets the advantages of recopulation by disturbing the ovipositing female and by increasing female mortality. Females which received multiple matings for 6 days prior to oviposition laid no more eggs than once-mated females. Multiple matings needed to be distributed over a long period to be beneficial. Females each kept with 5 males laid fewer eggs, because excessive mating interrupted ovipositing females and increased mortality. Continuously crowded once-mated females laid fewer eggs than isolated once-mated females. Crowding reduced oviposition by limiting oviposition sites. When females were crowded without limited oviposition sites, oviposition was not reduced. Crowding did not significantly increase female mortality in the absence of males. Females crowded continuously with males laid fewer eggs, because males disturbed ovipositing females and increased female mortality, and because oviposition sites became limited. Oviposition began within 72 hours of copulation and increased to a peak during weeks 2–4. Fertility was slightly reduced at the onset of oviposition; greatest fertility occurred around the 5th week. Fertility of oncemated females was slightly reduced, apparently because of a shortage of sperm late in the oviposition period. Lone once-mated females laid and lived longer than females kept with males. Females kept with males lived longer than the males.