Reproductive potential in the parasitoid Eupelmus orientalis (Hymenoptera: Eupelmidae)

Abstract

AbstractEupelmus orientalis (Crawford) (Hymenoptera: Eupelmidae) is a solitary ectoparasitoid of the larvae and pupae of West African bruchids. Since the biology of this species was unknown, studies were carried out on its reproductive biology. The age-dependent fecundity and offspring production of virgin and mated females of E. orientalis were determined under laboratory conditions at 33°C:23°C, 50%:80% r.h., L:D 12:12 on its host Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae) during the first 15 days of the life cycle. No differences were found between virgin and mated females for any parameter. A study of the age-dependent fecundity and offspring production was also carried out under the same conditions over the entire life cycle of mated females. The resulting data were used to determine the longevity and reproductive potential of the species, particularly through the calculated life tables and estimation of the intrinsic rate of increase. With ten hosts per female per day, E. orientalis females had a mean longevity of 45.75±5.09 days. They laid an average of 219.91±39.08 eggs, parasitized 154.27±26.17 hosts, and produced 166.77±9.41 offspring, consisting of 80.46±14.10 males and 86.31±10.04 females. The total mean developmental time was 18.58±0.22 days for males and 20.03±0.21 days for females. The net reproductive rate (Ro) was 62.33 female progeny per adult female, and the intrinsic rate of population increase (rm) was 0.1389 per day. The generation time (G) was 29.76 days and the doubling time (DT) 4.99 days. These results constitute the first step to determine the potential of E. orientalis as an agent for the biological control of bruchidae, especially C. maculatus.