A survey of the eggs, larvae and adults of Helicoverpa zea (Boddie) was conducted during the winter, spring and fall in Sete Lagoas, MG, in silking stage of corn (Zea mays) fields. It was obtained a high number of eggs, specially when the silks were still green. This amount was not associated with the small number of larvae, neither with the constant number of adults collected from pheromone traps. Mortality factors associated with the eggs and small larvae played important role in the natural suppression of the pest. For this reason, the decision about control measures in the study area, based on the egg sampling or on the males catches in pheromone traps do not indicate necessity of control. Sampling based on larvae in the silking stage is the best form to detect the economic damage level of H. zea in corn. The constant availability of food source and the favorable climatic conditions probably made impossible the detection of peaks of males in the pheromone traps.
Insecta; pheromone; corn phenology; survey; sampling
