Surveying Populations Of Delia Radicum (Diptera: Anthomyiidae) And Its Associated Natural Enemies In Organic Cauliflower In California

Delia radium is a root-feeding pest of cole crops. In California, the biocontrol agents associated with D. radicum are not well understood. Soil samples and sentinel pupae were used to assess D. radicum densities and associated beneficial insects present in cauliflower fields. Delia radicum parasitoids collected from soil samples included Aleochara bilineata (Coleoptera: Staphylinidae) and Aphaereta pallipes (Hymenoptera: Braconidae). Out of 10 sentinel pupae per sample, an average of 2.2 were preyed upon when placed on the soil surface, compared with only 0.3 when buried. Comprehensive (e.g. multi-seasonal) surveys are recommended to better understand D. radicum biocontrol opportunities in California.