Location: Crop Improvement and Protection Research
Project Number: 2038-22430-003-002-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2025
End Date: Aug 31, 2026
Objective:
Determine efficacy of chlorobenzene fumigation against ham mites and provide support to ARS lab for ham mite fumigation research.
Approach:
Ham mite (Tyrophagus putrescentiae) is a major pest of dry cured ham, aged cheese, and pet foods and requires effective management. There is a severe lack of fumigants for controlling ham mites. Phosphine is the only fumigant that is available to control ham mites on cured meat since methyl bromide has been phased out globally. However, phosphine fumigation is problematic in controlling ham mites in aging houses in commercial trials due to a lack of complete control of ham mites and corrosion to ham plants. Sulfuryl fluoride is a commonly used fumigant for structure fumigation. However, ham mites have high tolerance to sulfuryl fluoride fumigation. Sulfuryl fluoride fumigation of 48 h at a high dose even at a high temperature of 40°C could not achieve effective control of ham mites.
Chlorobenzene is a newly discovered fumigant in the ARS Salinas laboratory. Sulfur dioxide (SO2) is also a focus of ARS Salinas' research for postharvest pest control. In preliminary tests, both chlorobenzene fumigation and SO2 fumigation have been demonstrated to be effective against mobile life stages of ham mites, a major pest of ham products in ham aging facilities. The cooperator is a well-known scientist with extensive knowledge and research experiences in ham mite management.
This agreement is intended to support collaborated research between ARS and the cooperator's laboratory by using the cooperator's expertise and resources to further advance research on ham mite control with chlorobenzene fumigation and SO2 fumigation treatments. Specifically, chlorobenzene fumigation trials will be conducted in the cooperator's lab at Kansas State University on infested ham products to develop a chlorobenzene fumigation treatment on infested ham. Infested ham with all life stages of ham mite will be sealed in fumigation chambers. Chlorobenzene liquid will be injected into fumigation chambers and deposit on a substrate to allow evaporation. The fumigation chambers will be kept sealed for 24-48 h to complete fumigation. Vapor concentrations of chlorobenzene will be measured using detector tubes during fumigation. At the end of fumigation, fumigation chambers will be aerated in a fume hood. The fumigated ham products will be kept overnight before mortality of ham mites were checked. Modifications of treatment procedures such as chlorobenzene dose and treatment time will be made to achieve complete control of all life stages of ham mite.
The cooperator's lab will also provide multiple batches of infested ham samples to ARS lab for SO2 fumigation tests. Ham products will be inoculated with ham mites and reared for a certain length of time to establish ham mite culture on ham. The infested ham will be shipped to ARS lab in Salinas to be fumigated with SO2 to determine an effective SO2 fumigation treatment for ham aging facility treatment.