On-site confirmatory test, film wrapped bales, and shipping conditions of a multiple quarantine treatment to control Hessian fly (Diptera : Cecidomyiidae) in compressed hay

No Hessian fly, Mayetiola destructor (Say), adults emerged from infested wh eat seedlings (15,377 total puparia) in an on-site confirmatory lest when e xposed to compression and fumigation (60 g/28.3 m(3) aluminum phosphide) in hay bales in 5 different locations ill a freight container. Mean temperatu res in the freight container ranged from 15.4 to 19.6 degrees C during the 7-d Fumigation in a heated building. Hydrogen phosphide residues were below the U.S. Environmental Protection Agency tolerance of 0.1 parts per millio n in animal feeds 1 and 3 d after aeration. The successful completion of th e on-site confirmatory test allowed approval in December 1996, of timothy, alfalfa, oat, Sudan grass,and Bermuda grass hays for export to Japan. Hydro gen phosphide concentrations in film wrapped and unwrapped units of compres sed timothy hay were not significantly different throughout the 7-d fumigat ion period of the multiple quarantine treatment. The data showed that use o f film-wrapped units of compressed hay bales would not diminish the efficac y of the treatment: and was approved by regulatory agencies in December 199 7. The highest bale temperatures in freight containers of either timothy, a lfalfa, Sudan grass, or Bermuda grass hays were recorded on days 1-3 (mean +/- SE) (range of 15.87 +/- 0.02 degrees C to 27.44 +/- 0.02 degrees C) dur ing ocean freight from Seattle, WA to Nagoya, Japan. Lowest temperatures en route were recorded on days 7-9 (range, of 6.75 +/- 0.03 degrees C to 9.59 +/- 0.02 degrees C). The range of the mean percentage relative humidity (me an +/- SE) was 31.7-60.0 for all species of hay at 3-d intervals during 12 d of ocean freight. Mean bale temperatures and relative humidities during o cean freight were in general tower than optimum for growth and development of Hessian fly.