Last week I read an informative article written by Chris DiFonzo in Michigan State University's Crop Advisory Alert, volume 16, no. 9, June 2, 2001. Chris is an extension entomologist at Michigan State University. She had become aware of the rather recent registration of a new insecticide, Tracer, manufactured by Dow AgroSciences. This insecticide had been registered for use on cotton, but the label was revised in early May to include registrations for use on field corn, seed corn, popcorn, teosinte, wheat, barley, buckwheat, rye, and oats. Tracer also is registered for use on sorghum, milo, pearl millet, proso millet, grain amaranth, and soybeans.|
The active ingredient of Tracer (and Spintor for use on fruits and vegetables) is spinosad, one of a new class of insecticides called naturalytes. These insecticides are derived from the naturally occurring metabolites of the actinomycete fungus Saccharoployspora spinsoa. They are characterized as reduced-risk insecticides based on their low human toxicity and low impact on beneficial insects. Spinosad is a contact and a stomach poison but is typically more effective as a stomach poison.
Among the insects included on the revised Tracer label are armyworm in corn (2 to 3 fl oz per acre) and wheat and other small grains (1.5 to 3 fl oz per acre). Also included on the Tracer label are European corn borer in corn (1 to 3 fl oz per acre); corn earworm and southwestern corn borer in corn (2 to 3 fl oz per acre); armyworm, corn earworm, southwestern corn borer, and webworm in sorghum (1.5 to 3 fl oz per acre); green cloverworm in soybean (1 to 2 fl oz per acre); armyworm, corn earworm, and saltmarsh caterpillar in soybean (1.5 to 2 fl oz per acre); and cereal leaf beetle in wheat and other small grains (1.5 to 3 fl oz per acre). Preharvest intervals for corn grain, sorghum grain, soybean, and wheat grain are 28 days, 7 days, 28 days, and 21 days, respectively.
We have had limited experience with this new insecticide. However, we will search for efficacy data and offer some information about its performance in trials throughout the United States.--Kevin Steffey