Avoidance of multiple oviposition in Meteorus pulchricornis (Hymenoptera: Braconidae)

Abstract

Meteorus pulchricornis is a solitary endoparasitic koinobiont of free-living lepidopteran larvae. To test the avoidance of multiple oviposition, 20 individuals of 2nd instar larvae of Spodoptera litura were put together with a young or old female wasp for 24 hours for oviposition. We examined the distribution pattern of eggs deposited in twenty hosts after 24 hours oviposition in order to test the presence of host discrimination by female wasps to avoid multiple oviposition to the larvae of S. litura. The standardized Morisita index of dispersion (Ip) for the number of eggs in a host larva was almost always below zero, and the 95% confidence intervals of the means were significantly lower than zero for both 1–2-day-old (F = 2.10, df = 5, 14; P = 0.07) and 10-day-old females (F = 2.07; df = 4, 9; P = 0.10), indicating that multiple oviposition tends to be avoided, although it is not completely.