1a. Objectives (from AD-416):
Conduct basic and commercial tests to determine the effectiveness of PH3, PH3+CO2, and modern compressors to control Hessian fly in single or combined treatments, and the effect of postharvest hay handling practices on Hessian fly mortality in the laboratory and field.
1b. Approach (from AD-416):
Hessian fly will be reared in the greenhouse at the USDA, ARS, Parlier and Manhattan. Basic fumigation tests will be conducted in the facilities provided by the ARS in Parlier and the National Hay Association in California, Oregon, and Washington. Laboratory dose-response fumigation tests will determine the effect of temperature, exposure time, and PH3 or PH3+CO2 dosage on Hessian fly mortality, and establish a treatment schedule. Large-scale fumigation tests at hay handling facilities will confirm the efficacy of a proposed PH3 or PH3+CO2 fumigation schedule as a quarantine treatment. Bale compression tests at hay handling facilities will be used to determine the effect of compressors on mortality of Hessian fly puparia. Large-scale compression tests will be used to confirm the efficacy of bale compression alone or in combination with fumigation as a quarantine treatment. Basic tests will determine the effect of postharvest drying and bale curing on Hessian fly mortality. Data will be provided to The National Hay Association in support of market access for hay exports from the western U.S.
3. Progress Report:
This project is related to the sub-objective of the related in-house project to develop new quarantine strategies to control regulatory pests in exported hay. A new multiple quarantine treatment using bale compression and a three day hydrogen phosphide fumigation was developed to control Hessian fly, a pest of regulatory concern in exported hay. The treatment was tested in a large scale commercial test and the results submitted in a February 2013 report to the Japan Ministry of Agriculture, Forestry and Fisheries for approval as a certified treatment. Approval will result in a shorter handling time for processing exported hay bales and increase the volume of product shipped under the certification program. Biological control agents were studied in an organic alfalfa field to determine the potential of natural enemies to control Hessian fly puparia prior to harvest as a component of a systems approach to mitigate the pest in exported hay. The work helps assure trade partners that Hessian fly will not be accidentally introduced through hay imported from the western US.