Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2011
Publication Date: 8/1/2011
Citation: Tobin, P.C., Zhang, A., Onufrieva, K., Leonard, D.S. 2011. A field evaluation of the effect of temperature on the release of disparlure from a pheromone-baited trapping system used to monitor the gypsy moth (Lepidotera: Lymantriidae). Journal of Economic Entomology. 104(4):1265-1271. Interpretive Summary: The gypsy moth is one of the most ecological and economic damaging insect pests of hardwood forests and urban landscapes in northeastern Unites States, which defoliates millions of trees, annually. More than 250,000 traps baited with sex attractant are deployed across the United States each year to monitor their activity as part of Integrated Pest Management program. Because the traps are deployed across a geographically large area and are exposed to varying climates, efficacy of the traps might be affected by different release rate of the sex attractant at different locations. We measured the release rate of gypsy moth sex attractant from traps from 1-3 years across a broad geographic region, from northern Minnesota to southern North Carolina and found that there were significant differences in release rates over time among locations. The research result provided the relationship between climates during the period of trapping and the release rates of the synthetic attractants from lure devices. This information will help governmental agencies, e.g. forest service and animal and plant health inspection service, as well as researchers and growers, not only to ensure that traps are efficient in attracting the gypsy moth pest, but also to develop more effective insect pest management strategies for different target pests at different climatic conditions.
Technical Abstract: Traps baited with disparlure, the synthetic form of the gypsy moth, Lymantria dispar (L.), sex pheromone are used to detect newly founded populations and estimate population density across the United States. Consequently, the lures used in trapping devices are exposed to field conditions with varying climates, which can affect the rate of disparlure release. We evaluated the release rate of disparlure from delta traps baited with disparlure string dispenser from 1-3 yr across a broad geographic gradient, from northern Minnesota to southern North Carolina. Traps were deployed over approximately 12 wk that coincided with the period of male moth flight and the deployment schedule of traps under gypsy moth management programs. We measured a uniform rate of release across all locations when considered over the accumulation of degree days; however, due to differences in degree day accumulation across locations, there were significant differences in release rates over time among locations. The initial lure load appeared to be sufficient regardless of climate, although rapid release of the pheromone in warmer climates could affect trap efficacy in late season. Daily rates of release in colder climates, such as Minnesota and northern Wisconsin, may not be optimal in detection efforts. This work highlights the importance of local temperatures when deploying pheromone-baited traps for monitoring a species across a large and climatically diverse landscape.