Disrupting spring colonization of Colorado potato beetle to nonrotated potato fields

Overwintering Colorado potato beetles ( Leptinotarsa decemlineata (Say)) were concentrated primarily within woody borders, and mortality was lower in borders than in potato fields. After overwintering, only 15–44% of live beetles were in the potato fields. In experiments with small plots, colonization of fields from woody borders was reduced ∼ 60% by a trap crop, either treated with adulticide or with beetles collected daily. Such trap crops, or simply pitfall traps to prevent colonization from woody borders, could significantly reduce early‐season adult numbers and subsequent larval populations. However, success is dependent on the local densities of overwintered beetles, and the prevalence of arrestment behavior in the case of trap crops.