1a. Objectives (from AD-416):
To develop a postharvest methyl bromide fumigation schedule for sweet cherries against oriental fruit fly and Mediterranean fruit fly for export.
1b. Approach (from AD-416):
1) Establish colonies of fruit flies. 2) Determine most tolerant species and stage of fruit fly in sweet cherries via dose-response curves to MB fumigation in small chambers. 3) Conduct large scale efficacy tests to demonstrate efficacy of treatment. 4) Assess postharvest quality of cherries after fumigation.
3. Progress Report:
The goal of the agreement is to develop a postharvest methyl bromide (MB) fumigation schedule for sweet cherries against oriental fruit fly and Mediterranean fruit fly for exports, which contributes to objective 1 of the in-house project, "Develop new or improved postharvest treatments, including alternatives to methyl bromide, for tropical fruit, vegetable, and ornamental crop exports to ensure security against quarantine pests and to meet quarantine requirements of U.S. trading partners". Supplies and equipment needed to initiate the MB fumigations were obtained (i.e. methyl bromide, chambers, gas chromatograph, syringes, fruit fly diets, cages and containers to hold infested cherries). We initiated small-scale fumigations to determine the response of oriental fruit fly immature stages (eggs, first instar, second, instar and third instar) to MB in small laboratory chambers using infested cherries. Initial results suggest that the second instar stage of oriental fruit fly was the most tolerant stage to MB. Several different doses of MB and fumigation times and temperatures such as 46 and 54 degrees F were also tested in these initial studies. Doses of up to 4 pounds of MB for 4 hours were tested. Future tests are aimed at determining the optimal temperature, time and dosage (Concentration X time= CT) needed to test efficacy on a larger scale.