title: Hessian Fly (Diptera: Cecidomyiidae) Mortality in Export Bale Compressors and Response to a Hydrogen Phosphide and Carbon Dioxide Gas Mixture.
abstract: Hessian fly, Mayetiola destructor (Say), puparial mortality was evaluated in three modern hay compressors that produce compressed standard and large-size bales for export to Asia-Pacific countries. Pressure on bales ranged from 93.4 to 139.4 kg/cm2, causing 90.0-99.9% mortality of 10,891-23,164 puparia. Puparial response to a cylinderized hydrogen phosphide (1.8-2%) and carbon dioxide (97.8-98%) gas mixture was evaluated as a potential quarantine treatment using 2-4 d-exposures to low, medium, and high doses of 0.73-0.86, 1.05-1.26, and 1.39-1.56 mg/liter, and temperatures of 5.87±1.14, 9.84±0.05, 16.14±0.14, and 20.35±0.11°C. Accumulative concentration multiplied by time products (mg h/liter) at all fumigation temperatures for low, medium, and high fumigant doses were 34.9-37.7, 52.2-54.3, and 67.9-73.1 for 2 d; 52.7-60.6, 77.9-89.2, and 102.1-110.7 for 3 d; and 69.9-82.0, 99.4-118.2, and 132.3-146.8 for 4 d, respectively. An increase in mortality was significantly related to an increase in fumigation duration at 5, 10, and 15°C, and an increase in fumigant dose at 10 and 15°C. Puparial mortality ranged from 97.2 to 100% at all doses and durations at 20°C with no survivors at the highest dose for 3 d and the mid- and highest dose for 4 d. Bale compression is currently used in the first phase of a multiple quarantine treatment to control potential Hessian fly contaminants in exported hay. The novel fumigant may have application as a single quarantine treatment for noncompressed, standard exported bales.
authors.affiliation: USDA-ARS, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Ave., Parlier, CA 93648. Corresponding author, e-mail: victoria.yokoyama.science@gmail.com.
authors.forename: Victoria Y
authors.initials: VY
authors.lastname: Yokoyama
authors.affiliation: USDA-ARS, Crop Production and Pest Control Research, 901 West State St., West Lafayette, IN 47907.
authors.forename: Sue E
authors.initials: SE
authors.lastname: Cambron
authors.affiliation: Dried Fruit Association of California, 1855 South Van Ness Ave., Fresno, CA 93721.
authors.forename: Jeannette
authors.initials: J
authors.lastname: Muhareb
mesh_terms: D000821:Animal Feed; D000818:Animals; D002245:Carbon Dioxide; D004175:Diptera; D005651:Fumigation; D010720:Phosphines; D014908:Triticum
chemical_list: D010720:Phosphines; D002245:Carbon Dioxide; C044646:phosphine
keywords: Mayetiola destructor (Say); commodity treatment; hydrogen phosphide and carbon dioxide gas; quarantine security