Monday, December 10, 2007 - 10:29 AM

Field evaluation of organic insecticides to control the harlequin bug, Murgantia histrionica, and the yellowmargined leaf beetle, Microtheca ochroloma, on leafy greens in southern Oklahoma

Lisa M. Overall, and Jonathan Edelson, Oklahoma State University, 127 Noble Research Center, Stillwater, OK

Research was conducted over two successive years to compare effectiveness of registered organic insecticides for managing leafy green pests in the southern United States. Two major pests are the Harlequin bug (HB), Murgantia histrionica (Hahn)(Heteroptera: Pentatomidae), and the yellow margined leaf beetle (YMLB), Microtheca ochroloma Stål (Coleoptera: Chrysomelidae). These insects were chosen as models because they have different feeding behaviors. The YMLB feeds by chewing leafy material while the HB uses a piercing-sucking feeding method. Treatments evaluated were Organic Materials Review Institute listed and included Neemix 4.5, Entrust, and Pyganic EC 1.4 at 0.73 L (AI)/ha, 207.5 g (AI)/ha, and 4.68 L (AI)/ha, respectively. Field trials were conducted at the Wes Watkins Agriculture Research and Extension Center, Lane, OK. Plots of turnips and collards were treated using an ATV mounted sprayer. In 2007, results indicated that Entrust and Pyganic significantly reduced YMLB adult numbers 96% and 63%, respectively, one day post treatment compared to the untreated plot. In 2006 and 2007, Entrust and Pyganic significantly reduced HB adults 61% and 73%, respectively, compared to the untreated plot one day post treatment. These results are being used to develop IPM strategies for producing organically grown leafy greens.

Species 1: Coleoptera Chrysomellidae Microtheca ochroloma (yellowmargined leaf beetle)
Species 2: Hemiptera Pentatomidae Murgantia histrionica (harlequin bug)