Mating disruption of the spiny bollworm, Earias insulana (Lepidoptera: Noctuidae), with Shin Etsu twist-tie ropes in Israel

Abstract

Shin Etsu twist-tie ropes containing the spiny bollworm (Earias insulana(Boisduval)) pheromone were tested for mating disruption in a cotton field in Israel during 1991. Two applications of the Shin Etsu rope formulation (1000 ropes/ha), containing 50 mg pheromone per rope, effectively disrupted mating of E. insulana, reduced damage to cotton bolls, and minimized the number of chemical treatments needed. The success of the mating disruption, which lasted for more than 3.5 months, was indicated by the following: 1. Reduction of trap catches in the pheromone-treated plot as compared with the control plot (commercially treated with insecticides). 2. Lower infestation of cotton bolls in the pheromone-treated as compared with the control plot. 3. Over 90% reduction in mating success in the pheromone-treated plot, as indicated by the number of mating pairs collected at night in the two plots. 4. Reduced number of insecticidal treatments applied in the pheromone-treated plot. The release rate of the pheromones was monitored by periodical gas chromatography analyses of the remaining pheromone in ropes. The half lives of the E. insulana and Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) formulations were similar, with t_1/2=45-60 days. In Israel, E. insulana and P. gossypiella infest cotton fields almost simultaneously and are controlled by the same insecticides. Therefore, the control of E. insulana with pheromones is essential in order to give reasonable meaning to the commercial application of pheromones for the control of P. gossypiella, as is practised today in many cotton fields. The present study indicates that control of E. insulana by the mating disruption technique is viable.