Field evaluation of select OMRI listed biorational insecticides against yellowmargined leaf beetle, Microtheca ochloroma (Coleoptera: Chrysomelidae) in organic crucifer vegetables

Field trails were conducted to evaluate the efficacy of select OMRI approved insecticides against yellowmargined leaf beetle (YMLB),Microtheca ochroloma in commercial organic crucifer vegetable fields in Alabama in 2007 and 2008. The following treatments were evaluated: PyGanic^®(a formulation of pyrethrum derived from flowers of chrysanthemum), Aza-Direct^®(Azadirachtin as active ingredient derived from seed kernel of neem plant), Entrust^®(a formulation of spinosad for use in organic crop production), and Mycotrol O^®(formulation of Beauveria bassiana). The study was conducted in small plots (18sq ft) using a randomized block design with five treatments and four replicates. Treatments were applied at field recommended rates on a bi-weekly schedule. Insecticide efficacy was determined by comparing densities of larvae and adults of YMLB, and crop damage ratings versus untreated control plots. Entrust^® consistently produced the lowest pest densities and mean damage ratings and was the most promising treatment. None of the other treatments was effective in reducing YMLB infestations.