Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 4, 2011
Publication Date: June 1, 2011
Citation: Yokoyama, V.Y. 2011. Approved quarantine treatment for Hessian fly (Diptera: Cecidomyiidae) in large-size bales and Hessian fly and cereal leaf beetle (Coleoptera: Chrysomelidae) control by bale compression. Journal of Economic Entomology. 104:792-798. Interpretive Summary: Hessian fly is a pest of quarantine concern in baled hay exported from the western states to Japan where the insect is not found. Methods to control the pest were needed to ensure Japan and other Asia-Pacific and western Asian countries that Hessian fly would not be accidentally introduced through U.S. hay imports. A quarantine treatment using bale compression and phosphine fumigation was developed and approved by Japan for control of Hessian fly in large-size, compressed hay bales using timothy as the representative species of hay. In addition, compression of large-size bales was investigated as a control method for Hessian fly and a second quarantine pest, cereal leaf beetle, by placing insects into the bales and applying pressure in baling machines. Only low numbers of Hessian fly puparia survived and all cereal leaf beetle adults were killed showing the technique could be used as an alternative control method to chemical fumigation for hay exports. The research supports the continuous shipment of 2.7 to 3 million tons of U.S. hay valued at $675-750 million each year into Japan, Korea, United Arab Emirates, China, Vietnam, and other Asian countries.
Technical Abstract: An approved quarantine treatment using bale compression (32 kg/sq cm of pressure) and phosphine fumigation (61 g/28.2 cu m) aluminum phosphide for 7 d at 20 degrees C) was determined to control Hessian fly, Mayetiola destructor (Say), in large-size, polypropylene fabric-wrapped bales exported from the western states to Japan. No Hessian fly puparia (45,366) survived to the adult stage in infested wheat seedlings exposed to the treatment in a large-scale commercial test. Mean daily temperatures inside and among bales in three test freight containers were 17.8 front top, 17.0 front bottom, 17.3 middle bale, 15.7 middle air, 18.5 back top, and 18.1 degrees C back bottom, and below the proposed fumigation temperature of 20°C. Mean fumigant concentrations ranged from 208 to 340 ppm during the first 3 d, and ranged from 328 to 461 ppm after 7 d of fumigation. Copper plate corrosion values inside the doors, and in the middle of the large-size bales in all locations indicated moderate exposure to hydrogen phosphide. Hydrogen phosphide residues were below the U.S. Environmental Protection Agency tolerance of 0.1 ppm in animal feeds. On July 29, 2004 the research was approved by Japan and U.S. regulatory agencies, and regulations implemented on May 20, 2005. Compression in large-size bale compressors resulted in 3-3.6 and 0% survival of Hessian fly puparia and cereal leaf beetle, Oulema melanopus (L.), respectively. Bale compression can be used as a single treatment for cereal leaf beetle and as a component in a systems approach for quarantine control of Hessian fly.