Pink Bollworm (Lepidoptera: Gelechiidae): Field Testing a New Polyethylene Tube Dispenser for Gossyplure1

Abstract

Gossyplure, a sex attractant for the pink bollworm, Pectinophora gossypiella (Saunders), was applied by hand on 5 June to 2-ha cotton, Gossypium hirsutum L., fields using a polyethylene tube dispenser. Three doses were tested: 64.4 g (AI)/ha in one application (=894 dispensers/ha), and totals of 66.9, or 31.2 g (AI)/ha divided into three applications of 22.3 or 10.4 g each, respectively, on a 31-day schedule. In addition, untreated and insecticide-treated blocks of cotton were included for comparison. Trap catches in gossyplure-treated fields averaged <1 moth per trap per night until 13 August, an average reduction in catch of 94–98% compared to untreated and insecticide-treated cotton. The field treated with three applications of 10.4 g each had a significantly greater number of larvae per ha in blooms than the other test fields during the 27 June–20 July observation period. Fields treated with 64.3 g, or three applications of 22.3 g each, had significantly lower boll infestations than the field treated with three applications of 10.4 g each or the untreated field in 6 and 13 August samples. Populations of pink bollworm were not detected in the insecticide-treated field until late August. Females in mating stations in gossypluretreated fields remained unmated through mid-August tests. Mating occurred in untreated and insecticide-treated fields on six of seven test dates. Tests of tube dispensers collected from fields during the test period indicated a half-life of ca. 58 days and a gossyplure emission rate of 1.03 mg/day and 0.35 mg/day for the first and last 10 days of that period.