Ground Beetle (Coleoptera: Carabidae) Populations in Commercial Organic and Conventional Potato Production

In 2 consecutive years, ground beetles (Coleoptera: Carabidae) were sampled in commercial organic and conventional potato fields, using pit fall traps. Four conventional and 3 organic potato fields were surveyed to determine ground beetle taxa composition. In a related study, potato fields were assigned to 1 of 4 transitional systems to include: organic, no spray (usually referred to as no control and/or only OMRI certified control), IPM-conventional (directed control, after sampling) and conventional (broad spectrum pesticides) systems. Seven taxa of ground beetles were identified: Anisodactylus kerbyi Lindroth 1953, Amara sp., Bembidion sp., Calosoma cancellatum Eschscholtz 1833, Calathus ruficollis Casey 1920, Calathus ingratus Dejean 1828, and Pterostichus adstrictus Eschscholtz 1823. With the exception of C. cancellatum, which was not identified from organic fields in the first yr of this study, all taxa were collected in both organic and conventional potato fields both yr. Based on total number of specimens collected, Bembidion sp., R adstrictus and Amara sp. represented 42.8% of the total specimens collected. The smallest number of ground beetles was collected from no spray and IPM-conventional systems. This study provides basic valuable information regarding beetles populations for growers making transition from conventional to organic potato production.