INTER-LARVAL COMPETITION AND ITS SUBSEQUENT EFFECT ON PEDIOBIUS-FURVUS (HYM, EULOPHIDAE) BROODS FOR THE MANAGEMENT OF GRAMINEOUS STEM BORERS

The effects of superparasitism on the size, rate of development, proge ny production, sex ratio and percentage parasitism of the parasitoid P ediobius furvus (Gah.) and the number of parasitized hosts producing m ature parasitoids were investigated High parasitoid egg densities in h osts were obtained using two host densities (1 and 2) and three arbitr ary parasitoid densities (1, 2 and 5) under two exposure times (12 and 24 h). Superparasitism in P. furvus resulted in a reduction in the nu mber of adults that matured and a reduction in the size and prepondera nce of male production. Dissections of the parasitized host pupae of t he stem borer Chile partellus (Swinhoe) showed no combat among develop ing wasps. Immature supernumeraries were eliminated by starvation and/ or suffocation. The results showed that P. furvus larvae are not harme d by surplus food material in their hosts and that the female parasito id preferred to lay more eggs into unparasitized than into parasitized host pupae.