Nitric oxide fumigation for control of ham mite, Tyrophagus putrescentiae (Sarcoptiformes: Acaridae)

Authors: Yang, Xiangbing; Liu, Yong Biao; SINGH, RIPPY - Former ARS Employee; PHILLIPS, THOMAS - Kansas State University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2022
Publication Date: 2/11/2022
Citation: Yang, X., Liu, Y., Singh, R., Phillips, T.W. 2022. Nitric oxide fumigation for control of ham mite, Tyrophagus putrescentiae (Sarcoptiformes: Acaridae). Journal of Economic Entomology. 115(2):501-507. https://doi.org/10.1093/jee/toac014.
DOI: https://doi.org/10.1093/jee/toac014

Interpretive Summary: The ham mite, Tyrophagus putrescentiae (Schrank), is a common pest on stored products including cheese, dried fruits, and meats. Management of this mite historically has relied on fumigation with methyl bromide, an ozone-depleting chemical that is now strictly regulated. Recently, nitric oxide (NO) fumigation has been demonstrated to be a safe, effective alternative for control of postharvest insects and mites. Therefore, scientists from ARS and Kansas State University collaborated to evaluate efficacy of NO fumigation against different stages of the ham mite on both lab diet and ham meat. The results showed that NO fumigation was effective against all mite stages under laboratory conditions at 25°C. In general, the eggs were the most tolerant stage to NO fumigation. On lab diet, 100% mortality of eggs was observed after 48, 24, 16, and 8 h treatments at 0.5, 1.0, 1.5, and 2.0% NO concentration, respectively. Immature and adult mites were less tolerant to NO fumigation, requiring significantly less time to achieve 100% control at the same doses. Additional tests conducted on ham meat showed similar results, confirming the efficacy of NO against ham mite. This study identifies NO fumigation as an effective, more environmentally friendly alternative to methyl bromide treatments for control of mite pests in cured-ham.

Technical Abstract: The ham mite, Tyrophagus putrescentiae (Schrank), is a common pest infesting stored products such as cultured cheese, dried fruits and meats, including aged hams. Nitric oxide (NO) fumigation is a recently discovered treatment that is effective for control of postharvest insects and mites. In this study, we report the efficacy of NO fumigation at various concentrations and treatment times under laboratory conditions against different stages of T. putrescentiae on both dietary media and ham meat. Our results showed that NO fumigation was effective against all stages of T. putrescentiae with 100% control achieved at all tested concentrations at 25°C. In general, the T. putrescentiae egg was the most tolerant stage to NO fumigation. On dietary media, 48, 24, 16, and 8 h treatments were needed to achieve 100% mortality at 0.5, 1.0, 1.5, and 2.0% NO concentrations, respectively. Tyrophagus putrescentiae mobile immatures and adult stages were less tolerant to NO fumigation, with 100% mortality achieved after 16, 8, 8, and 4 h treatments at 0.5, 1.0, 1.5 and 2.0% NO concentrations, respectively. Also, the median lethal concentration (LC50) of NO on T. putrescentiae eggs was determined to be 0.86, 0.68, and 0.32% for 8, 16, and 24 h treatments. In addition, a confirmatory test conducted on ham meat showed similar efficacy. Complete control of T. putrescentiae eggs was achieved after 48 and 24 h treatments at 0.5, and 1.0% NO concentrations, respectively, and 100% control of larvae and adults was observed after 16 and 8 h at 0.5 and 1.0% NO concentrations, respectively. Our results demonstrated that NO fumigation is effective against T. putrescentiae and can be a potential alternative treatment to methyl bromide for cured-ham pest control.