Does Host Size and Feeding Status Influence the Egg Load of Microplitis rufiventris (Hymenoptera: Braconidae)?

Abstract

Laboratory experiments were conducted to determine the effect of host instar and feeding status on the egg load of early life stage in Microplitis rufiventris Kokujev (Hymenoptera: Braconidae), a solitary koinobiont endoparasitoid of some noctuid pests. The wasps that developed from fourth or fifth instars of Spodoptera littoralis (Boisduval) larvae were heavier in weight than those from earlier stages. Different numbers of mature eggs were found in the two ovaries of the female wasp. Egg loads, corresponding to fitness, were significantly influenced by female weight and feeding status. However, the interactions between the two treatment factors were not significant. The average number of mature eggs carried by females at eclosion time ranged from 52 eggs in smaller wasps to 62 eggs in larger wasps. Females that were fed had higher egg loads and egg maturation rate than unfed females. However, female wasps were capable of maturing considerable number of eggs without feeding; suggesting that they produce a certain portion of eggs from nutritional reserves that had been stored during larval stage. Female wasps are weakly synovigenic, with an egg maturation at a rate of ≈1.8 eggs per h. Further investigation is required to verify the rate of egg maturation and eventually egg resorption in different stages of adult female M. rufiventris.

Host‐dependent larval migration and parasitism risk in a polyphagous moth

“…Our results confirmed that M. rufiventris is synovigenic, having some eggs at emergence but producing more during its adult life (Khafagi et al, 2011), although the egg loads at emergence in our study were higher than those in Khafagi et al's study. As in most parasitoids, M. rufiventris development time, egg load, longevity, and size were previously shown to be affected by the host quality, through host age or plant host (Altahtawy et al, 1976;Hegazi et al, 2007), so the observed impact of host plant on cocoon size, adult longevity, and female egg load was not surprising.…”

Egg maturation dynamics of the parasitoid Microplitis rufiventris: starvation speeds maturation in early life

“…It is a synovigenic species (i.e. females emerge with few mature eggs with further egg maturation during the course of their life time) (Khafagi et al ., 2011). Detailed information on the reproductive biology of this wasp will help with respect to evaluating its potential for reducing host populations of S. littoralis.…”

Pattern of Egg Maturation and Oviposition forMicroplitis rufiventris(Hymenoptera: Braconidae) Wasps Given Different Schedules of Host Availability and Food Resources

“…rufiventris female is weakly synovigenic (Khafagi et al 2011). The females are ready to lay abundant eggs within few hours after eclosion.…”

“…Adult sugar meals can affect parasitoid egg load but this effect appears to vary among parasitoid species. Whereas some studies have found a positive effect of sugar meals on egg load (Riddick 2007, Dieckhoff and Heimpel 2010, Khafagi et al 2011) others have found either no effect (Wang and Messing 2003, Giron et al 2004, Lee et al 2004 or a negative effect (Olson et al 2000).…”