Thesis (BS Biology) -- University of the Philippines Mindanao, 2001

This study on the Brachymeria obscurata, a corn borer parasitoid, described its mergence, courtship and mating, adult longevity, flying habits and the external morphology of the head, thoractic and abdominal appendages including the parasitization rate and abundance. Collection was done in several corn-growing communities in Cotabato, Bukidnon and Davao City. The insect parts studied were excised, mounted and photographed. The B. obscurata emerges usually in daytime, from 6:00 to 9:00 A.M., emerging from the anterior part of the corn borer?s pupal case. Courtship precedes mating. The female B. obscurata has a longer longevity and larger body size than the male. The adult parasitoid has geniculate antennae and mandibulate mouthpart; a reduced prothorax and metathorax fused to the enlarged mesothorax; a highly-reduced wing venetion and nine abdominal segments. The parasitization rates of B. obscurata were highest in Manolo Fortich and Tupi, perhaps due to the minimal pesticide application done in these areas. The rate was higher in November than in October due to the optimal environmental conditions and the parasitoid?s density-dependent action. The relative abundance per corn plant and plat area planted to corn are highest in Tupi and Manolo Fortich, indicating that there is sufficient initial population for the succeeding generation