Potential for evolution of resistance to pheromones: Interindividual and interpopulational variation in chemical communication system of pink bollworm moth

Abstract

After an extensive examination of the release rates and blend ratios of pheromonal components emitted by field-collected femalePectinophora gossypiella (Saunders), we find no evidence of resistance to pheromones applied to cotton fields to disrupt mating. Females from fields with 3-5 years of exposure to disruptant pheromones as well as those from fields with only minimal exposure to disruptant pheromones emitted (Z,Z)-7,11-hexadecadienyl acetate at a rate of ca. 0.1 ng/min and (Z,E)7,11-hexadecadienyl acetate at ca. 0.06 ng/min. The ratio of pheromonal components was much less variable than the measured emission rate and was centered about a 61:39Z, Z to Z,E ratio. In contrast to the blend ratio emitted by females, the composition of the pheromonal blend used in monitoring populations and disrupting mating is centered about 50:50 Z,Z to Z.E. In general there was a remarkable consistency in the release rate and blend ratio among populations of females throughout southern California and those from a laboratory colony. It would appear that, although resistance to theP. gossypiella pheromone is still a very real possibility when it is used heavily in pest management as a mating disruptant, there are current agricultural practices and conditions which would hinder its development.

Experimental Evidence for Three Pheromone Races of the Scarab Beetle Phyllophaga anxia (LeConte)

“…Cembran pine populations of Z. diniana utilize (E)-9-dodecenyl acetate as their pheromone, whereas the larch populations utilize (E)-11-tetradecenyl acetate (Baltensweiler et al 1978;Baltensweiler and Priesner 1988). In contrast, analyses of populations of the pink bollworm moth, Pectinophora gossypiella, sampled in several areas of the world (Haynes and Baker 1988), and the cabbage looper moth, Trichoplusia ni, sampled across the USA (Haynes and Hunt 1990), demonstrated little variation in female produced pheromone blends.…”

Field and Laboratory Responses of Male Codling Moth (Lepidoptera: Tortricidae) to a Pheromone-Based Attract-and-Kill Strategy

“…To determine whether males were contacting attracticide droplets before capture in female-baited traps, a system to reliably mark males responding to droplets in the Þeld was developed. This method was a modiÞcation of that developed by Haynes and Baker (1988). Each marking station consisted of a single 50-mg droplet placed in the center of a plastic 29-ml cup lid measuring 6.5 cm in diameter.…”

Insect Pheromones and their Use in Pest Management

“…The blend ratio of the pink bollworm, Pectinophora gossipiella, shows little variation among insects from California, Argentina, Brazil, China, Egypt, Mexico and Pakistan (Haynes and Baker, 1988). Ratios of (Z,Z)-7,11-16 acetate to its (Z,E) isomer varied from a maximum of 63.1% (+2.1 %) in Pakistan to a minimum of 57.5% (+4%) in China.…”