Title: USING THE EAG AS A QUALITY CONTROL TOOL TO MEASURE PHEROMONE IN THE FIELD
Tcheslavskaia, K - VIRGINIA TECH
Submitted to: Annual Gypsy Moth Review Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 31, 2001
Publication Date: October 1, 2002
Citation: Thorpe, K.W., Tcheslavskaia, K.S. 2002. Using the eag as a quality control tool to measure pheromone in the field. Annual Gypsy Moth Review Proceedings.
Interpretive Summary: The gypsy moth is a serious pest of forests and shade trees in northeastern United States. In 2001, over 200,000 acres of forests were treated with the gypsy moth sex pheromone, disparlure, to disrupt mating and slow the rate at which populations of this pest are expanding to the west and south. An important advantage of this method is that, unlike most other control methods available for this pest, mating disruption only affects the gypsy moth and therefore has no unintended environmental impacts. The purpose of this study was to determine the feasibility of using a portable electroantennogram device (EAG) to measure pheromone levels in the air in areas treated with mating disruptants as a way of assessing the quality of the treatment. An EAG uses a moth antenna connected to electrodes to measure pheromone levels in the air. The strength of electrical impulses produced by the antenna indicate the amount of pheromone in the air. Measurements were taken over a range of pheromone application rates. Higher EAG readings were obtained in plots treated with the highest rates of mating disruptant. However, it appeared that the highest rates tested were near the limit of the ability of the EAG to detect pheromone in the air. While the results show that the EAG can measure pheromone in the air, further refinement of the technique is needed. The information presented in this report will help government agencies, gypsy moth control specialists, and other persons interested in gypsy moth mating disruption programs understand the prospects for using the EAG to measure pheromone levels in areas treated for gypsy moth mating disruption and its limitations.
Mating disruption was used to slow the spread of gypsy moth populations on over 200,000 acres of forested land in the United States in 2001. A study was conducted to determine the feasibility of using a portable electroantennogram device (EAG) to measure the concentration of gypsy moth sex pheromone in the air in treated areas as a way to assess the quality of fmating disruption treatments. A portable EAG unit manufactured by Syntech (Hilversum, The Netherlands) was purchased and used to collect measurements from replicated plots in central Virginia that were treated with a microcapsule formulation (3M Corporation, London, Ontario) of racemic disparlure, the synthetic sex pheromone of the gypsy moth, at application rates ranging from 0.15 g/ha to 75 g/ha. A portable calibration device (VICI Metronics Inc., Santa Clara, CA) was used to calibrate the EAG device in the field. Higher EAG readings were obtained in plots treated at the highest rates, although the levels of pheromone in the plots appeared to b near the threshold of detection of the EAG. While the results of this study provide additional evidence that portable EAG devices can be used to detect and measure pheromone levels in areas treated with gypsy moth mating disruptants, additional refinement of the EAG, calibrator, and measurement protocols are needed to reduce the variability associated with the EAG measurements.