Pink Bollworm (Lepidoptera: Gelechiidae): Further Tests with (Z,Z)-Isomer of Gossyplure1

Abstract

Effects of a single application of 78 g (AI)/ha of the (Z,Z)-isomer (89% pure) of gossyplure, the sex pheromone of the pink bollworm, Pectinophora gossypiella (Saunders), or applications of conventional insecticides on trap catches and boll infestations by the moth, were compared in 2-ha fields of cotton, Gossypium hirsutum L. Traps were baited with 1 mg of 9:1, 3:1, or 1:1 ratios of (Z,Z)- to (Z,E)-isomers to monitor blend preferences of native and released male moths. Additional field plot tests were conducted to determine the effects of (Z,Z)-isomer on male moths surrounding a 0.6-ha treated plot and to compare the effects of treatments of gossyplure or (Z,Z)-isomer on trap catch for 2 mo after treatment. Trap catches in the field treated with (Z,Z)-isomer were reduced 97% in June and July compared with the insecticide-treated field, and males were primarily caught in traps baited with 9:1 ratio. Boll infestations were comparable in the two fields until the third month after treatment, when the field treated with (Z,Z)-isomer became heavily infested (35.0 compared with 1.0 pink bollworms per 50 bolls in late August). Recapture of males released 90 d after treatment in the field treated with (Z,Z)-isomer was reduced 95% compared with recapture in an untreated field. Males in the field surrounding a O.6-ha block treated with (Z,Z)-isomer showed an altered response (50% of catch in traps baited with 9:1 ratio) to the maximum test distance of 214 m during a 2-wk period after treatment. Total trap catches of 18, 14, or 3,598 males per plot were obtained in other plots treated with (Z,Z)-isomer, gossyplure, or left untreated during a 2-mo period after treatment.