European Corn Borer Control in Peppers1

Abstract

In recent years heavy infestations of the European corn borer, Pyrausta nubilalis (Hbn.), in peppers grown in the “Delmarva” area have greatly reduced yields, Additional losses have occurred through the rejection of infested peppers by inspectors at the canneries. Field experiments were conducted in 1959 to test dosages, formulations, schedules, and a sticker, primarily using DDT to control this pest. An improved “Slosser”-type spray boom especially designed to spray peppers was used for 11 randomized treatments, replicated 4 times, in 3 fields. Excellent control of the European corn borer was obtained with DDT and Sevin but not with toxaphene. There were no significant differences between weekly and 10-day spray schedules, or between wettable powder and emulsion formulations of DDT, or between DDT at 1 or 2 lb./acre rates, or between DDT or Sevin® (1-naphthyl methylcarbamate) with and without a sticker (Plyac) in a 7-day schedule. Excellent control was achieved by the DDT-plus-sticker treatments, applied on a 10- day schedule, suggesting that spray intervals might be lengthened beyond the weekly spray periods. Observations on timing of sprays and borer development in Delaware indicated the need for continuous insecticide protection for peppers during periods of adult flights, egg deposition and emergence of young larvae. Heavy infestations of the tobacco hornworm, Protoparce sexta (Johan.), and the cabbage looper, Trichoplusia ni (Hbn.), were very common in the untreated plots. Practically no infestations of these two species occurred in the DDT and Sevin treatments. Green peach aphid, Myzus persicae (Sulz.), populations were very high during August and September, particularly in the DDT treatments. Malathion applied at the recommended rates failed to control them.