Life history characteristics of Aphidius transcaspicus, a parasitoid of mealy aphids (Hyalopterus species)

Aphidius transcaspicus Telenga (Hymenoptera: Braconidae: Aphidiinae) is a solitary koinobiont endoparasitoid that has been selected for use as a biological control agent against the mealy plum aphid Hyalopterus pruni (Geoffroy) (Hemiptera: Aphididae) in prune orchards in California. Using the alternative host Aphis fabae Scopoli (Hemiptera: Aphididae) on the host plant Vicia faba L., we determined the adult longevity and fecundity, and progeny development time and sex ratio of A. transcaspicus. Mated female parasitoids were given new, individually-enclosed, host-infested bean plants each day of her adult life. Mummified hosts were monitored daily for adult progeny emergence. Adult lifespan of parent females averaged 6.67 ± 0.56 days, and mean lifetime mummy production was 196.1 ± 19.9 per female. There was a significant linear relationship between total mummy production and both adult female weight at eclosion and adult female longevity. Mean development time of progeny was 13.3 ± 0.1 days, and varied significantly with sex and parent female age. Overall, 74% of parasitoid mummies survived to adult eclosion, but survival decreased with parent age. Lifetime sex ratio was 0.53 female, and sex ratios declined with female age. The intrinsic rate of natural increase was estimated to be 0.21, with net reproductive rate of 31.10, and mean generation time of 16.35 days.