Habitat manipulation in potato affects Colorado potato beetle dispersal

Abstract

AbstractIncreased habitat complexity in agricultural fields can alter the movement of pests into or within a field. Using a mark–release–recapture method with Colorado potato beetle [Leptinotarsa decemlineata (Say)], we compared the tenure time and dispersal of marked insects released within experimental potato fields to those released at the field borders in three trials in summer 2006. Plots within fields had rye, vetch or no plant residues. Movement of marked Colorado potato beetles into the tilled plots was significantly higher than into vetch or rye cover treatments. The abundance of naturally occurring beetles in the three cover treatments followed the general patterns of the number of marked immigrants over all releases. Marked beetles released inside the potato field tended to move along the release row rather than across rows; this pattern was stronger for the tilled treatment than for the two mulch cover treatments. Marked beetles disappeared from within the potato fields differently, depending on the cover crop treatment, but the patterns were not consistent over the season. Incorporation of dispersal patterns into pest management strategies should improve methods of pest population regulation, especially for the initial colonization of fields.