Impact and Management of Late-Season Populations of the Colorado Potato Beetle (Coleoptera: Chrysomelidae) on Potato in Connecticut

Experiments were conducted during three seasons to quantify the relationship between yields of late-maturing potato variety and variation in densities of second-generation larvae of the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), in Connecticut and to develop alternative strategies to regular insecticide applications for maintaining commercially acceptable second-generation CPB densities. In the most extreme case, after first-generation cpa densities were reduced ~6 per stem, the second cpa generation attained a density of nearly 20 per stem without affecting yields. A pest management program, including different treatment guidelines for firstand second-generation larvae in conjunction with antifeedant fungicides, allowed full yield production without the need for any insecticide applications during the second larval generation. Antifeedant fungicides alone suppressed second-generation larvae well below densities necessary to cause yield reductions.