|Arthur, Franklin - Frank|
Submitted to: Journal of Economic Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/9/2002
Publication Date: 4/1/2003
Citation: YUE, B., WILDE, G.E., ARTHUR, F.H. EVALUATION OF THIAMETHOXAM AND IMIDACLOPRID AS SEED TREATMENTS TO CONTROL EUROPEAN CORN BORER AND INDIANMEAL MOTH (LEPIDOPTERA: PYRALIDAE) LARVAE. JOURNAL OF ECONOMIC ENTOMOLOGY 96(2):503-509. 2003. Interpretive Summary: Stored seeds are subject to attack by both field crop pests and stored product pests, however, there has been little effort to include stored product pests as part of evaluation studies for seed treatments. In this test, we compared Gaucho, (imidacloprid), a standard seed treatment, with a new product, Cruiser (thiamethoxam), against European Corn Borer and Indianmeal moth larvae. Cruiser was equally effective for controlling mature larvae of both moth species, while Gaucho was slightly less effective against mature Indianmeal moth larvae compared to Cruiser. Farmers and warehouse managers who are storing seed can use either insecticide to protect the seed, but higher rates of Gaucho may be needed to ensure complete control of both the European Corn borer and the Indianmeal moth.
Technical Abstract: Efficacy of Cruiser and Gaucho were evaluated as seed treatments in stored grain for controlling European corn borer, Ostrinia nubilalis (Hubner) and Indianmeal moth, Plodia interpunctella (Hubner). At room temperature of approximately 22-25 degrees C., all fifth instar European corn borer larvae died after 2 or 4 d exposure in corn treated with 500 or 250 ppm Cruiser, respectively. All were killed after 3, 4 and 6 d exposure to 400, 300 and 200 ppm Cruiser, respectively, at 29 degrees C. Mortality was lower on grain treated with 100, 50, 25 and 12.5 ppm Cruiser. At 29 degrees C., the LC50 ranged from 7.2-85.9 ppm and the LC90 from 46.9-399.3 ppmafter 2, 3, 4, 5 and 6 d exposure to treated grain. Diapausing European corn borer larvae were effectively controlled (100% mortality) in grain treated with 250 and 500 ppm Cruiser after 10 and 4 days, respectively. Gaucho was less toxic to fifth instar European corn borer larvae at room temperature, with mortalities of 22.0 and 48.0% after 2 and 4 d, respectively, in corn treated with 937.5 ppm. All first, second, and third instar Indianmeal moth larvae died after a 5 d exposure to corn grain treated with 50 ppm or higher Cruiser while 94.0% mortality of the third instar larvae occurred in sorghum treated with the same concentration. Higher concentration and longer exposure periods were required to control the latter instars or mature larvae. Gaucho had similar but slower effects than Cruiser on Indianmeal moth larvae.