Dimethoate dipping of Kensington mango against Queensland fruit fly

Abstract

Dipping mangoes (Mangifera indica) for 0 5 or 3 min. in solutions of dimethoate (nominally 375 or 500 mg/litre, see below) was highly effective against infestations of Queensland fruit fly, Dacus tryoni (Froggatt), with more than 99.9% mortality. Residual dimethoate from dipping fruit for 3 min in dimethoate solution (nominally 500 mg/litre) was below the Australian maximum residue limit of 2 mg/kg. The procedure is not a replacement for fumigation with 1,2-dibromoethane in all circumstances but should be acceptable for all but very high risk markets. Differences between calculated (nominal) and actual strengths of dimethoate dip solutions could not be accounted for by hydrolysis.