Submitted to: National Hay Association
Publication Type: Other
Publication Acceptance Date: 4/1/2010
Publication Date: 4/1/2010
Citation: Yokoyama, V.Y. 2010. Hessian fly mortality by phosphine-carbon dioxide fumigation and postharvest drying. National Hay Association, International Market Development Research Report, No. 1, March 17, 2010. National Hay Association, Tampa, Florida. p.5. Interpretive Summary: Quarantine treatments and strategies are needed to control Hessian fly, a pest of regulatory concern in hay exported from the western states to Pacific Rim countries. A novel fumigant, composed of a mixture of phosphine and carbon dioxide gas, was tested and found to control the pest after a four day treatment. In tests that simulated different regional harvesting climates, long drying periods for cut hay and summer weather conditions caused high Hessian fly mortality. The work helps show that the risk is negligible for accidental introduction of the pest into foreign markets via U.S. hay exports.
Technical Abstract: Hessian fly, Mayetiola destructor (Say), puparia, the stage of regulatory concern that may be found in weeds contaminating exported hay, may be controlled with a phosphine and carbon dioxide gas mixture dispensed from cylinders at a minimum dose of 750 ppm, temperature of 20°C (68°F) or higher, and duration of 4 days. Hay harvesting and drying practices can increase the mortality of Hessian fly puparia, especially in warm and arid climates where export quality hay is grown. Test procedures using a high number of insects helps show that hay handling techniques and postharvest treatments control Hessian fly in hay harvested and exported from the western U.S.