Quo Vadis the fumigants?

Abstract

Fumigation is the most widely used procedure to control stored product pests to prevent economic and quality losses by providing various application methods and penetration capability into the treated commodity. However, most of the available fumigants have limitations in use due to various reasons. Methyl bromide (MB), according to Montreal Protocol, is scheduled to be phased out worldwide by 2015. Sulphuryl fluoride (SF) is known to have limited efficiency on egg stages of insects. Reportedly, it also contributes to the greenhouse effects, which may jeopardize its future use. Currently, phosphine (PH₃) is the most widely used fumigant worldwide due to its low cost and ease of application, though resistance observed in major pest species threatens the continued use of PH₃. Recent studies in beetles reveal that phosphine resistance is governed through two genes on separate autosomal chromosomes. Research on new fumigants continue to be restricted due to concerns over the adverse effects of fumigant residues in food and the environment that led regulatory agencies to take actions by imposing strict limitations on fumigant registration. On the other hand the phase out of MB and resistance to PH₃ has stimulated significant interest on development of alternatives like modified atmospheres (MAs), thermal disinfestation and irradiation. In Turkey, MAs applications are preferred for the treatment of organic food products and are performed mostly in transportable PVC structures (Cocoons or Volcani Cubes). In museums high nitrogen or SF applications are the only procedures to eradicate structural pests. Under the given constraints of registration of new fumigants, it is anticipated that more attention will be devoted to develop novel alternative treatments that are economically feasible, sustainable, user friendly and environmentally benign.

Keywords: Fumigants, Modified atmospheres, Insect resistance, Stored products pests, Fumigant alternatives