Development of a meteorological model to evaluate significant events in the movement of the gypsy moth front in Wisconsin

The spread of the gypsy moth in Wisconsin is a problem that has been identified as major by the USDA/Forest Service. The mean rate of spread in Wisconsin since the gypsy moth was introduced in the mid-1990s has been approximately 10km/yr higher than that observed in other areas. This suggests that some phenomena specific to the region is affecting the spread of the population and resulting in ‘enhanced dispersal' in the area. This project will examine the dispersal from a meteorological standpoint that has not been previously investigated. This study explores the feasibility of using a conditional meteorological model to explain the observed changes in moth distribution patterns in Wisconsin in the period 1995–2006. The model incorporates wind speed and direction at ‘source' points near known gypsy moth populations in Michigan, wind speed and direction at ‘target' points in Wisconsin, and precipitation rates along trajectories in between the ‘source' and ‘target' points. The results are then compared to the observed gypsy moth population patterns to determine what meteorological conditions coincide with the ‘enhanced dispersal' events. It is envisioned that the model may later be used in other locations and would aid in the management of the gypsy moth population.