Electroantennogram measurements of atmospheric pheromone concentration after aerial and ground application of gypsy moth mating disruptants

Abstract

A portable electroantennogram (EAG) sensor was used to measure relative atmospheric pheromone concentration in forest plots treated with aerial and ground applications of gypsy moth, Lymantria dispar (L.) (Lep., Lymantriidae), mating-disruption formulations. Five treatments (Disrupt II flakes with sticker, Disrupt II flakes without sticker, Disrupt II flakes in a sticker slurry, microcapsules and hand-applied Luretape), all applied at 75 g active ingredient per hectare and an untreated control were evaluated. Gypsy moth male catch in pheromone-baited traps and fertilization of deployed females were suppressed in all treatments, and no females deployed in treated plots produced more than 5% fertile eggs. Relative pheromone concentrations were significantly higher in the two treatments in which flakes were aerially applied with sticker and in the microcapsule treatment. Pheromone concentration measurements in the flakes without sticker and hand-applied treatments were not significantly different from those in the control. Mating success was negatively correlated with relative pheromone concentration. The ability of the EAG to detect differences in pheromone concentration that are correlated with mating success suggests that this could be a useful method for predicting the effectiveness of mating-disruption treatments.

The potential for monitoring and control of insect pests in Southern Hemisphere forestry plantations using semiochemicals

“…Examples in forestry include mating (Brown et al 2006) a Systems where the knowledge is applied for control disruption of Eucosma sonomana and Rhyacionia zozana for several weeks after pheromone application, resulting in a population reduction of two thirds for each of the separate years studied (Gillette et al 2006). Sex pheromones used for mating disruption were shown to reduce isolated gypsy moth, L. dispar, populations by 90%, eliminating reproduction in these isolated populations beyond the leading edge of this pest (Thorpe et al 1999(Thorpe et al , 2007b.…”

Measurement by electroantennogram of airborne pheromone in cotton treated for mating disruption of Pectinophora gossypiella following removal of pheromone dispensers

“…Measurements using a system with one standard stimulus (mostly non-pheromone) as reference signal (van der Pers & Minks, 1998) have been widely used (Ryne et al, 2001;Thorpe et al, 2007). Measurements using a system with one standard stimulus (mostly non-pheromone) as reference signal (van der Pers & Minks, 1998) have been widely used (Ryne et al, 2001;Thorpe et al, 2007).…”

“…The high sensitivity and fast response of the EAG are unique assets that have drawn investigators to its use in pheromone detection. Measurements using a system with one standard stimulus (mostly non-pheromone) as reference signal (van der Pers & Minks, 1998) have been widely used (Ryne et al, 2001;Thorpe et al, 2007). These devices yield EAG amplitudes relative to a stimulus that itself has no direct relationship to the pheromone-sensing channel, but that may represent the 'fitness' of the antenna.…”

“…These devices yield EAG amplitudes relative to a stimulus that itself has no direct relationship to the pheromone-sensing channel, but that may represent the 'fitness' of the antenna. As a constant relationship between the reaction to the non-pheromone stimulus and the sensitivity to pheromone cannot be established with different antennae, only shortterm comparisons between 'treated' and 'untreated' plots can be made, unless a large number of readings with different antennae is used, under the assumption that the sensitivity of an 'average' antenna is a reproducible quantity (e.g., Thorpe et al, 2007). Using only one reference signal cannot assign quantitative relations between two readings, because the logarithmic dose-response curve (a known property for many moth species) is not Figure 6 Experiment 4.…”

Use of a Sprayable Sex Pheromone Formulation in Landscape-Level Control of Choristoneura fumiferana Populations

“…The lack of demographic effect was attributed to moth dispersal into relatively small (30-100 ha) treatment blocks, obscuring any tangible effects of pheromone treatment. Additionally, the deposition of pheromone on or near the forest floor due to the nature of the flakes themselves rather than in the tree canopies where the target adult moths are mostly found may impact treatment efficacy [12,33,35].…”