ARS | Publication request: The treatment of fresh fruit from California with methyl bromide for postharvest control of light brown apple moth, Epiphyas postvittana (Walker)

Submitted to: Controlled Atmosphere & Fumigation in Stored Products International Conference
Publication Type: Proceedings
Publication Acceptance Date: May 24, 2012
Publication Date: N/A

Interpretive Summary: Postharvest chamber fumigation is a critical element of the California specialty crop industry, as it provides a biological safeguard against pests and, in many scenarios, is the only available tool for government and industry to guarantee pest-free security and food safety. Failure to disinfest specialty crops in trade and marketing channels can result in insect- and microbial-derived damage with severe consequences to economic profitability and consumer health. This report describes the insecticidal efficacy of methyl bromide toward light brown apple moth (LBAM), a pest that is currently under quarantine in California and has the potential to serve as a trade barrier for fresh fruit exports. Exposures above 60.0 (mg h/L) at 60 F and 71.8 (mg h/L) at 50 F resulted in the complete mortality of 6,755 and 6,118 larvae, respectively, and support the conclusion that the minimum methyl bromide exposure requirements of the APHIS T104-a-1 treatment schedule are efficacious against LBAM.

Technical Abstract: Methyl bromide chamber fumigations were evaluated for postharvest control of light brown apple moth (LBAM), Epiphyas postvittana (Walker), in fresh fruit exports. To simulate external feeding, larvae were contained in gas-permeable cages and distributed throughout loads of peaches, plums, nectarines, apples, raspberries, or grapes. Differential sorption between replicate fumigation trials and across commodities produced a range of exposures that were verified by gas-chromatographic quantification of methyl bromide headspace concentrations. Concentration x time cross products (CTs) 60 and 72 mgL^-1h at 50 and 60 F, respectively, resulted in complete mortality of ~ 6,500 larvae at each temperature, the greatest number of larvae tested to date in confirmatory context.