Artificially raising the CO2 or N2 levels and/or reducing oxygen levels in an enclosed environment, known as controlled atmospheres (CA), may induce sublethal or lethal effects in insect pests of stored food products (Lum 1974, Shejbal 1980, Jay 1984). CA is a viable alternative to chemical fumigants for control of insect pests of stored-products, and has no detrimental effects on the overall storability of grain. The interaction between the modified atmosphere concentration, temperature, relative humidity, and exposure time on lethality has been examined for several stored-product pests (Jay 1984). CA has been used to extend the storage life of fruits and vegetables, such as apples and pears, by several months, using O2 in the range of 1 to 3% and CO2 in the range of 1 to 5%. To control arthropod pests, however, O2 levels must be greatly lowered to below 0.5%, and/or CO2 levels must be elevated to at least 20% and may need to be as high as 95%. Such concentrations of O2 or CO2 can cause injury to stored fruits and vegetables, so exposure times must be brief, on the order of two weeks to a few hours. Complete control of Pacific spider mite, western flower thrips, and omnivorous leafroller was achieved on table grapes with a 2 day exposure to 80% CO2 followed by 14 days of 8% CO2, or with a 1 day exposure to 80% CO2 followed by 14 days at 20% CO2. Grape quality was satisfactory (Mitcham 1998). Temperature also influences the success of CA for fruits and vegetables. Warmer temperatures with CA generally result in higher arthropod mortality, but may increase product injury. Atmosphere, temperature, and exposure time must be optimally combined to achieve adequate pest control while avoiding product injury.
Jay, E. 1984. Recent advances in the use of modified atmospheres for the control of stored-product insects. pp. 239-254. In: Bauer, F.J. (ed.) Insect Management for Food Storage and Processing. Amer. Assoc. Cereal Chem. St. Paul, MN.
Lum, P.T.M. 1974. Effect of carbon dioxide anaesthesia at eclosion upon mating efficiency of male Plodia interpunctella (Lepidoptera: Pyralidae). J. Stored Prod. Res. 10: 69-71.
Mitcham, E. 1998. Controlled atmospheres for control of insect and mite pests. In: Hall, J. & K. Robb (eds.). Proc. 14th Conf. Insect and Disease Mgt. on Ornamentals. Soc. Amer. Florists, Alexandria, VA. pp. 41-43.
Shejbal, J. (ed.) 1980. Proceedings International Symposium on Controlled Atmosphere Storage of Grains. Elsevier. Amsterdam. 608 pp.