Prediction of Gypsy Moth (Lepidoptera: Lymantriidae) Mating Success from Pheromone Trap Counts

Mating Disruption for the 21st Century: Matching Technology With Mechanism

“…On one transect, which was oriented along the valley, effects were observed as far away as 600 m. Female mating success increased gradually with distance from the edges of treated plots along the valley. There was a significant relationship between capture of males in traps and female mating success, and the relationship was similar to that which occurs in untreated areas (Sharov et al 1995). These results indicate that mating is disrupted up to 250 m from treated areas, and in some cases effects can be seen at distances up to 600 m. The close agreement of the trap catch and mating success values in both treated and untreated areas provides evidence that trap catch alone provides a useful measure of the effectiveness of mating disruption treatments.…”

“…To collect additional data on the relationship between trap catch and mating success, and to search for differences in this relationship that could be related to differences in spread rates, an experiment was conducted in northern Wisconsin. This experiment was a repeat of experiments conducted in Virginia and West Virginia in 1994 (Sharov et al 1995) and southern Wisconsin in 2000 (section 2000-Trap Catch Versus Mating Success in Southern Wisconsin, p. 45; Tcheslavskaia et al 2002). Based on male moth catches in pheromone traps, six plots were established in the Chequamegon-Nicolet National Forest and nearby forested sites during August at various distances from the advancing gypsy moth front.…”

“…Unmated females near the end of their life will lay unfertilized eggs. When daily trap catch of males in pheromone traps is low (<1 male per trap per day), which indicates a relatively low population density, corresponding female mating success is generally below 20 percent (Sharov et al 1995).…”

“…It was hypothesized that the difference in rate of spread could be the result of higher mating success of females in northern areas, leading to higher rates of population establishment and growth. To examine this possibility, an experiment was conducted in southern Wisconsin (Tcheslavskaia et al 2002) to determine if the relationship between trap catch and mating success there was different than the same relationship that had been determined previously in Virginia and West Virginia (Sharov et al 1995). Seven plots were established in the Kettle Moraine State Forest and nearby forested areas in Waukesha and Walworth Counties.…”

“…While previous efforts have quantified the relationship between gypsy moth mating success and daily trap capture (Sharov et al 1995; see section 2000-Trap Catch Versus Mating Success in Southern Wisconsin, p. 45, and section 2003-Trap Capture Versus Mating Success in Northern Wisconsin, p. 57), these studies were not conducted through the entire gypsy moth flight period, so they did not provide a means to relate mating success to male density through time. Also, it is not possible from these previous studies to relate mating success to season-long trap capture (SLTC), which is important because all gypsy moth population density data from the STS program are expressed in terms of season-long capture of males in pheromone-baited traps.…”