COMPARISONS OF 2 TRAPPING METHODS FOR HYLOBIUS-PALES (COLEOPTERA, CURCULIONIDAE) IN VIRGINIA

The pales weevil, Hylobius pales (Herbst), is a major regeneration pes t of Christmas tree plantations in the eastern United States, where tr aditional control measures include the use of highly toxic insecticide s. The development of an effective, easily implemented sampling strate gy to detect when serious infestations are imminent is highly desirabl e for reducing these preventative insecticide applications. Methods we re evaluated for trapping walking H. pales under 3 vegetation manageme nt treatments in Christmas tree plantations and for their potential to forecast seedling damage. Standard pit traps baited with natural host material and synthetic volatiles caught significantly more a pales th an polyvinylchloride (PVC) pitfall traps baited with synthetic volatil es alone. No gender differences were observed in response to the trap treatments. No differences in catch were observed between stationary t raps and traps rotated biweekly to different locations within each plo t. Vegetation management had no significant effect on trap catch. Howe ver, H. pales fed on a significantly higher proportion of eastern whit e pine seedlings, Pinus strobus L., in plots not managed for competing vegetation than in herbicide-treated plots. The data suggested a stro ng linear relationship between catch and seedling damage; these variab les were significantly correlated in 1995, but not in 1994. However, o ne must be cautious because this regression was based solely on 4 data points. The seasonal occurrence of H. pales in Virginia Christmas tre e plantations is reviewed in detail. Our results suggest we must rely on the use of pit traps for monitoring weevil populations in Virginia until an appropriate system for implementing the PVC pitfall trap is d eveloped.