Toxicity of the gas methyl isothiocyanate, MITC, as a fumigant for stored product arthropods

Fumigation is one of the best ways to stop infestation of stored products with pest arthropods.  Methyl bromide and phosphine are two of the most effective fumigants used.  However, methyl bromide will be phased out by 2015 as an ozone-depletor under the US Clean Air Act, and there are many reports of arthropods developing resistance to phosphine.  In this study we look at the toxicity of the gas methyl isothiocyanate (C₂H₃NS), MITC, to various pest arthropods.  Various life stages of the pest arthropods were exposed to different levels of methyl isothiocyanate and mortality was assessed.  Interestingly, when comparing the susceptibility of the life stages to methyl isothiocyanate, the egg stage appeared to succumb at lower gas concentrations than the other life stages, which his opposite to the case with other fumigants for which eggs area very tolerant life stage.  MITC shows good potential as a new fumigant for stored products.