Comparison of methods for deploying female gypsy moths to evaluate mating disruption treatments

Abstract

Abstract1 Mating disruption is the primary tactic used to reduce rates of gypsy moth population spread in the United States Department of Agriculture’s Slow‐the‐Spread of the gypsy moth programme (STS). Because STS targets very low‐density gypsy moth populations within which it is extremely difficult to collect females or egg masses, mating success in native populations cannot be determined. Therefore, the evaluation of mating disruption treatments in field experiments such as those designed to test new formulations and application methods requires deploying and recovering laboratory‐reared female moths to determine mating success.2 Five methods of deploying females were evaluated for cost, rates of female and egg mass recovery, and female mating success. The deployment methods tested were: modified delta trap, square barrier, single and double trunk bands, and tethered females.3 Deployment of tethered females had the highest cost and mating success rate, but it did not yield the highest rates of female and egg mass recovery. Deployment of females in delta traps produced the lowest cost and mating success rate, but yielded the highest recovery rate. Neither of these deployment methods is recommended because of unacceptably high cost (tethered female) or low mating success (delta trap).4 There were no significant differences in cost or mating success among the other three deployment methods.5 The differences among the square barrier, single trunk band, and double trunk band methods in cost, female and egg mass recovery, and mating success are too small to recommend any one over the others.