Location: Invasive Plant Research LaboratoryTitle: Preferential Edge Habitat Colonization by a Specialist Weevil, Rhinoncomimus latipes (Coleoptera: Curculionidae) Author
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2012
Publication Date: 12/1/2012
Citation: Hough-Goldstein, J.A., Lake, E.C., D'Amico, V., Berg, S.H. 2012. Preferential edge habitat colonization by a specialist weevil, Rhinoncomimus latipes (Coleoptera: Curculionidae). Environmental Entomology. 41:6:1466-1473. Interpretive Summary: The behaviors that an insect uses to disperse and find new host patches can be critical to its success as a biological control agent. We investigated these behaviors in the specialist weevil Rhinoncomimus latipes Korotyaev, a biological control agent of mile-a-minute weed, Persicaria perfoliata (L.) H. Gross. We released R. latipes at the forage edge with potted mile-a-minute plants, representing new host patches to colonize, arranged at different distances along the forest edge, into an open field, and into the forest. More than twice as many weevils found host plants located close to the release point compared to plants located further away. Six to 8 times as many weevils colonized plants along the forest edge compared to plants in the open field or within the forest. Weevils released in an open field also colonized more mile-a-minute plants along the forest edge than in the open field. The results indicate that R. latipes prefers to colonize mile-a-minute patches along forest edges and may not locate isolated patches in the open or those embedded in forests.
Technical Abstract: Understanding the behavioral basis of dispersal and colonization is critical in biological control systems, where success of a natural enemy depends in part on its ability to find and move to new host patches. We studied behavior of the specialist weevil Rhinoncomimus latipes Korotyaev, a biological control agent of mile-a-minute weed, Persicaria perfoliata (L.) H. Gross, by releasing weevils at the forest edge and monitoring their colonization of potted host plants arrayed along the edge, out into the open field, and into the forest. Both distance from the release cage and habitat where plants were located affected colonization, with more than twice as many weevils found on plants at 2 m than at 6 m or 14 m; at 14 m, 6 to 8 times as many weevils colonized plants along the forest edge compared to plants in the open field or within the forest. In a second experiment, weevils that were released in an open field 12 m from the forest edge initially flew in all directions, but again ultimately colonized more plants at the edge than out in the open field. This species may be adapted to seek host plants at the forest edge, because P. perfoliata is generally found in riparian corridors in its native range and along forest edges in North America. Results suggest that R. latipes will successfully move to new P. perfoliata patches along wooded edges, but may not readily locate isolated patches in the open or those embedded in forests.