Dispersal patterns and mark-and-recapture estimates of two pine root weevil species, hylobius pales and pachylobius picivorus (Coleoptera: Curculionidae), in Christmas Tree Plantations

The pales weevil, Hylobius pales (Herbst), and the pitch-eating weevil, Pachylobius picivorus (Germar), are pests of plantation pines in the eastern United States. Dispersal patterns of these species were studied in the summer of 1989 using pitfall traps baited with ethanol and turpentine, and mark-and-recapture techniques. Approximately 17% of H. Pales and 34% of P. Picivorus were recaptured. Most pales weevils were recaptured in the immediate vicinity of the release point, whereas pitch-eating weevils appeared to disperse farther before responding to the baits. Marked weevils were recaptured up to 8 wk following the release. No gender differences were found in recapture rates. Pronounced temporal differences in recapture rates were observed, with more weevils attracted to baits in spring than in summer. A separate baited trap was developed to monitor weevil flight. Total weevil numbers, and female H. Pales considered singly, were more commonly caught at 81 cm than 160 cm. The role of dispersal and migration in pine root weevil ecology is discussed with respect to the ability of these species to colonize new habitats.