Mating Behavior and Competitiveness of Gamma-Irradiated Olive Fruit Flies123

Abstract

The mating behavior and competitiveness of gamma-irradiated Dacus oleae (Gmelin) were studied. When pupae were irradiated 3 days before adult emergence with a dose of 8 krad, the resulting adult males mated a maximum of 24 times and inseminated females in the first 10 matings. Untreated males mated up to 28 times and transferred sperm at each copulation. At least ¼ ♀ remated. The mean interval between the 2 matings was progressively less when the 1st mating was to a normal male, a male irradiated in the adult stage, a male irradiated in the pupal stage, or an aspermic male. Irradiated males contribute competitive sperm and can reduce the fertility of a female previously mated to a normal male. In laboratory and field cage experiments, a ratio of 8 sterile ♂: 1 normal ♂male; gave satisfactory reduction of egg hatch.