DISTRIBUTION OF CHILO-PARTELLUS (LEPIDOPTERA, PYRALIDAE) EGG BATCHES ON MAIZE

Distribution of Chilo partellus egg masses was studied in field, green house, and laboratory experiments. The eggs were laid in batches mainl y on the lower side and the lower leaves of the plant. The egg batch s ize ranged from 1 to 169 eggs, with a median of 33.5 eggs per batch (a verage, 40.5). Oviposition of C. partellus is described at two levels. The first level, choice of oviposition plants, followed a random dist ribution. The second level, number of egg batches per plant, followed an aggregated distribution in the field, where more than one egg batch was deposited on the same plant by the same female, which was found o n 25% of the oviposition plants. A mechanism for egg-laying C. partell us females to perceive preceding oviposition or injured plants could n ot be detected. Oviposition site choice seemed to be mediated by tacti le stimuli.