Pink bollworm of cotton ( Pectinophora gossypiella (Saunders)): male moth catches in gossyplure-baited traps and relationships to oviposition, boll infestation and moth emergence

Pheromone-baited traps are an important sampling tool in integrated pest management programmes. Studies were conducted to determine the relationship between catches of male insects in these traps, and crop infestation. Numbers of male moths of the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), caught daily in cotton fields at the University of Arizona Cotton Research Center, Phoenix, Arizona, in gossyplure-baited traps were variable. However, average catches of male moths for 3–7 days between boll-sampling periods were strongly correlated with oviposition on cotton bolls, percentages of infested bolls and numbers of larvae per boll. Average weekly numbers of moths emerging from infested cotton were also strongly correlated with the number of males caught: the number of females emerging was strongly correlated with oviposition on cotton bolls. Insecticide applications of carbaryl and fenvalerate reduced catches of male moths of pink bollworm in gossyplure-baited traps compared with catches in traps in untreated fields (average 56%). However, 13–48 male moths/trap per night were caught in the treated fields after applications. Thus, scheduling treatments on the basis of male moth trap catches, except for the initial treatment, was not feasible. Small field sizes, moth immigration and/or continuing emergence from the infested cotton in the fields may have obscured the impact of the insecticide treatments on adult moth populations.