Kentucky State University
Effect of Entrust®, an Organic Insecticide, on Mortality and Progeny Production of Several Stored Grain Beetle Pests in Shelled Corn
Institution
Kentucky State University
Faculty Advisor/ Mentor
John Sedlacek; Karen Friley; Steve Hillman
Abstract
Between 2000-2004, shelled corn in Kentucky had an average annual value of $180 million. Over 50 % of the crop is placed in on-farm storage annually. While in storage corn can be infested by a wide variety of insect pests. Infestation results in damage and losses in Kentucky exceeding $18 million annually. Synthetic chemical control has been used as the primary method of insect control in stored grain for over 40 years. Concerns related to insecticide resistance, chemical residues on food and in the environment, and worker exposure has lead to development of some biologically-based insecticides such as SpinTor® 2SC. SpinTor is a broad spectrum insecticide that was found to be effective against several stored grain beetle species on shelled corn in storage. Recently SpinTor was re-formulated to conform to OMRI national standards. Because organically raised livestock and grain consumption are gaining in popularity and because there are few organic grain protectants, a laboratory study was conducted to determine efficacy of Entrust® on beetles infesting stored shelled corn. Shelled corn was treated with 1 ppm or 3 ppm of Entrust or left untreated. Mortality was quantified at 24, 72, and 168 hours after exposure. No significant differences in mortality was seen between treated and control groups of either Oryzaephilus surinamensis or Tribolium castaneum. However, corn treated at 3 ppm showed higher mortality and lower progeny production for Sitophilus zeamais. Results will be discussed within the context of using Entrust as an organic method of insect control.
Effect of Entrust®, an Organic Insecticide, on Mortality and Progeny Production of Several Stored Grain Beetle Pests in Shelled Corn
Between 2000-2004, shelled corn in Kentucky had an average annual value of $180 million. Over 50 % of the crop is placed in on-farm storage annually. While in storage corn can be infested by a wide variety of insect pests. Infestation results in damage and losses in Kentucky exceeding $18 million annually. Synthetic chemical control has been used as the primary method of insect control in stored grain for over 40 years. Concerns related to insecticide resistance, chemical residues on food and in the environment, and worker exposure has lead to development of some biologically-based insecticides such as SpinTor® 2SC. SpinTor is a broad spectrum insecticide that was found to be effective against several stored grain beetle species on shelled corn in storage. Recently SpinTor was re-formulated to conform to OMRI national standards. Because organically raised livestock and grain consumption are gaining in popularity and because there are few organic grain protectants, a laboratory study was conducted to determine efficacy of Entrust® on beetles infesting stored shelled corn. Shelled corn was treated with 1 ppm or 3 ppm of Entrust or left untreated. Mortality was quantified at 24, 72, and 168 hours after exposure. No significant differences in mortality was seen between treated and control groups of either Oryzaephilus surinamensis or Tribolium castaneum. However, corn treated at 3 ppm showed higher mortality and lower progeny production for Sitophilus zeamais. Results will be discussed within the context of using Entrust as an organic method of insect control.