Pheromone concentration measured with electroantennogram in cotton fields treated for mating disruption of Pectinophora gossypiella (Lepidoptera: Gelechiidae)

A field-portable electroantennogram (EAG) system was used to measure relative aerial concentrations of formulated pheromone applied to cotton fields for mating disruption of the pink bollworm, Pectinophora gossypiella (Saunders). This device uses a novel calibration system to measure 3 points in a dose-response curve within 5-8 s. We used this system to estimate the aerial concentrations generated by different types of formulation (applied at rates of 3-75 g [AI]/ha) at varying times after application and the wind-dependent transport of pheromone from treated into untreated fields. Pheromone levels presumed sufficient to cause behavioral effects were found at distances of up to 100 m from treated areas. In a plot (100 by 200 m) where formulation (75 g [AI]/ha) was applied only to the edge, substantial airborne pheromone was measured in the interior of the plot. Long-range pheromone transport suggests that deployment of disruptant along the border of a held may be a useful strategy for mating disruption. The EAG system provides a rapid method for measuring relative pheromone concentrations in fields treated with pheromone formulated for mating disruption. This methodology allows us to compare efficacy and longevity of release from various formulations and to document the spatial distributions of pheromone they generate.