Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/6/2010
Publication Date: 10/20/2010
Publication URL: http://hdl.handle.net/10113/46256
Citation: Basoalto, E., Miranda, M., Knight, A.L., Fuentes-Contreras, E. 2010. Landscape Analysis of Adult Codling Moth (Lepidoptera: Tortricidae) Distribution and Dispersal within Typical Agroecosystems Dominated by Apple Production in Central Chile. Environmental Entomology Vol 39(5):1399-1408. Interpretive Summary: Codling moth is an important pest of apple, pear, and walnut with a worldwide distribution. Populations can develop on unmanaged trees and fly into commercial orchards forcing growers to treat their orchards with prophylactic insecticide sprays. ARS researchers at the USDA, ARS, Yakima Agricultural Research Laboratory, Wapato, WA in collaboration with researchers at the University of Talca in central Chile have have developed traps and lures that are useful to study the movement of moths between managed and unmanaged sites. These studies found that moths originating from an unsprayed experimental orchard and from backyard trees were recaptured inside the commercial orchard at distances up to 800 m. These data provide solid evidence that non-commercial hosts of codling moth situated near orchards need to be managed or removed to allow growers to further reduce their use of insecticides.
Technical Abstract: We analyzed the spatial distribution and dispersal of codling moth, Cydia pomonella (L.), adults within two heterogeneous agro-ecosystems typical of central Chile; commercial apple, Malus domestica Borkhausen, orchards surrounded by various unmanaged host plants. Both a geostatistical analysis of catches of adult males with a grid of sex pheromone-baited traps, and an immunological self-marking technique combined with traps baited with a male and female attractant were used. The spatial analyses identified the key sources of moths within these diverse landscapes. Codling moth catches in traps were spatially associated within distances of approx. 150 to 300 m. Similarly, the mean distance from the immunological self-marking plots within the commercial apple orchard to the traps which captured marked adults was 282 m. In contrast, the mean distance in the capture of marked moths from unmanaged self-marking plots to a commercial orchard was 828 m. These data suggest that the success of any future areawide management programs for codling moth in Chilean pome fruit must include a component for managing or removing non-commercial hosts that surround orchards. This analysis also suggests that the selection pressure for resistance imposed by insecticide sprays within managed orchards is likely dampened by the influx of susceptible moths from unmanaged sites common in central Chile.