FORECASTING PICKLEWORM (LEPIDOPTERA, PYRALIDAE) LARVAL INFESTATIONS USING SEX-PHEROMONE TRAPS

Forecasting infestations of pickleworm, Diaphania nitidalis (Stoll), using a pheromone trapping system was studied in 42 cucumber fields during a 2-yr period. In all plantings (24) where moths and larvae were found, adult males were trapped before or during the same week that larvae were first detected in the crop. Thus, pheromone-baited traps provided advance warning of impending pickleworm damage. Pickleworm damage to cucumber fruit in plots that were not sprayed until moths were trapped was not significantly different from plots that were sprayed weekly. Withholding of spray treatment until moths were caught saved an average of one treatment per field with no loss of control. A modified box trap was developed that is more efficient than the original trap design.