Progress 08/01/04 to 07/31/07
Outputs
Application of vacuum, or low pressure, to a sealed system reduces the amount of all atmospheric gases and creates a low-oxygen atmosphere that kills insects through suffocation while causing no harm to durable agricultural products. Laboratory studies found that vacuum treatment at 50 mm Hg could kill all life stages of major stored product insects, and that generally the egg and the pupal stages were the most tolerant to vacuum. A commercial scale demonstration of vacuum treatments was conducted at a dried bean plant in California. A 5-ton "Cocoon" attached to an electric vacuum pump was used to treat 100-lb sacks of dried beans at the company's warehouse. Ventilated jars of beans infested with different life stages of the cowpea weevil were placed in the treatment to monitor efficacy. A large PITs Tunnel system was also tested at the bean plant. The PITs tunnel is a flexible PVC chamber about the size and dimensions of a 20-foot shipping container and when empty it
is held open by a metal frame. One-ton cloth tote bags of bean were loaded into the PITs tunnel using a forklift; a total of 10 totes were loaded. The PITs tunnel was sealed and evacuated with a pump to approximately 50 mm of Hg and held overnight. Additional laboratory work showed that the duration of an effective vacuum treatment could be reduced to four hours by the addition of low levels of the botanical insecticide ethyl formate. Educational programs about vacuum treatments were presented to groups of potential users at the national workshop on storage and handling of organic stored grains at Purdue University, West Lafayette, IN, at the national Pest Control Technology seminar held in Minneapolis, MN, and at the VIIth National Stored Product IPM Training Conference in Stillwater, OK.
Impacts
Vacuum treatments for high value commodities represent effective methods to control insect pests without use of any chemicals. Thus, vacuum represents an organically compliant method of pest control, and could be adopted by organic food companies or others who want to eliminate use of chemical insecticides. Pest control companies have used our information to help clients. Extension and training programs in the past year have shared information on vacuum treatment with several hundred potential users.
Publications
- Mbata, G. N., M. Johnson, T. W. Phillips and M. Payton. 2005. Mortality of life stages of the cowpea weevil..exposed to low pressure at different temperatures. J. Econ. Entomol. 98: 1070-1075.
- Thomas, E. and T. W. Phillips. 2004. Chapter 20. Fumigation. Pp. 1165-1261, In: Hedges, S. ed. Mallis Handbook of Pest Control, 9th edition. Mallis Publishing Co.
- Phillips, T. W. 2006. The Science and Technology of Postharvest Insect Control: Challenges, Accomplishments and Future Directions. Chapter 19, pp. 211-222, In: J. Heaps, ed., Insect Management for Food Storage and Processing, 2nd Ed. Am. Assoc. Cereal Chem.
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Progress 10/01/05 to 09/30/06
Outputs
Laboratory studies found that vacuum treatment at 50 mm of mercury could kill all life stages of the cowpea weevil, and that the pupal stage was the most tolerant to vacuum. A commercial scale demonstration of vacuum treatments was conducted at a dried bean plant in California. A 5-ton 'Cocoon' attached to an electric vacuum pump was used to treat 100-lb sacks of dried beans at the company's warehouse. Ventilated jars of beans infested with different life stages of the cowpea weevil were placed in the treatment to monitor efficacy. A large PITs Tunnel system was also tested at the bean plant. The PITs tunnel is a flexible PVC chamber about the size and dimensions of a 20-foot shipping container and when empty it is held open by a metal frame. One-ton cloth tote bags of bean were loaded into the PITs tunnel using a forklift; a total of 10 totes were loaded. The PITs tunnel was sealed and evacuated with a pump to approximately 50 mm of Hg and held overnight. Educational
programs about vacuum treatments were presented to groups of extension educators and potential users at the VIIth National Integrated Pest Management Symposium in St. Louis, MO, 5 April 2006. Extension publications are being prepared on vacuum technology and other controlled or modified atmosphere methods for insect control.
Impacts
Vacuum treatments for stored products represent effective methods to control pests in bagged commodities without use of any chemicals. Thus, vacuum represents and organically compliant method of pest control, and could be adopted by organic food companies or others who want to eliminate use of chemical insecticides.
Publications
- Phillips, T. W. 2006. The Science and Technology of Postharvest Insect Control: Chapter 19, pp. 211-222, In: J. Heaps, ed., Insect Management for Food Storage and Processing, 2nd Ed. Am. Assoc. Cereal Chem.
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Progress 10/01/04 to 09/30/05
Outputs
Laboratory studies found that vacuum treatment at 50 mm Hg could kill all life stages of the cowpea weevil, and that the pupal stage was the most tolerant to vacuum. A commercial scale demonstration of vacuum treatments was conducted at a dried bean plant in California. A 5-ton 'Cocoon' attached to an electric vacuum pump was used to treat 100-lb sacks of dried beans at the company's warehouse. Ventilated jars of beans infested with different life stages of the cowpea weevil were placed in the treatment to monitor efficacy. A large PITs Tunnel system was also tested at the bean plant. The PITs tunnel is a flexible PVC chamber about the size and dimensions of a 20-foot shipping container and when empty it is held open by a metal frame. One-ton cloth tote bags of beans were loaded into the PITs tunnel using a forklift; a total of 10 totes were loaded. The PITs tunnel was sealed and evacuated with a pump to approximately 50 mm of Hg and held overnight. Educational
programs about vacuum treatments were presented to groups of potential users at the national workshop on storage and handling of organic stored grains at Purdue University, West Lafayette, IN, and also at the national Pest Control Technology seminar held in Minneapolis, MN.
Impacts
Vacuum treatments for stored products represent effective methods to control pests in bagged commodities without use of any chemicals. Thus, vacuum represents and organically compliant method of pest control, and could be adopted by organic food companies or others who want to eliminate use of chemical insecticides.
Publications
- Mbata, G. N., M. Johnson, T. W. Phillips and M. Payton. 2005. Mortality of life stages of the cowpea weevil, Callosobruchus maculaturs (F.) (Coleoptera: Curculionidae), exposed to low pressure at different temperatures. J. Econ. Entomol. 98: 1070-1075.
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Progress 10/01/03 to 09/30/04
Outputs
Ethyl formate is a naturally occurring volatile in some grains, fruits and vegetables that is insecticidal; it is exempted from a requirement of a tolerance by EPA and it is generally regarded as safe (GRAS) as a food additive. Laboratory studies found that the most tolerant life stages of key stored grain pests could be killed with exposure to ethyl formate, and that mortality could be increased by increase in temperature and by a combination treatment with a partial vacuum. Ethyl formate formulated with carbon dioxide will be tested in the future under commercial conditions. Ethyl formate may offer a low risk, natural product alternative to traditional chemical insecticides for commodity disinfestation. An investigation into the effect of low pressure alone on apples infested with apple maggots, Rhagoletis pomonella, revealed that it may also be useful for disinfesting perishable commodities. Infested apples were treated at 25 and 50 mm Hg pressures at 25 and 30
degrees C for exposure period ranging from 2 to 120 hours. Mortality was determined by comparing with the controls at ambient pressure. Eggs were the most tolerant stage followed by larvae. Exposure time for 99% mortality decreased with increase in temperature and pressure. However, at 30 degrees C the quality of apples in terms of appearance and taste may be affected.
Impacts
These results suggest a new use for ethyl formate as an insecticide when combined with vacuum, and can lead to a new product for pest control.
Publications
- Mbata, G. N., T. W. Phillips and M. Payton. 2004. Mortality of eggs of stored-product insects held under vacuum: effects of pressure, temperature and exposure time. J. Econ. Entomol. 97: 695-702.
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