Methyl Bromide Toxicity at Various Low Temperatures and Exposure Periods to Angoumois Grain Moth and Indianmeal Moth in Popcorn12

Abstract

Methyl bromide (MeBr) was evaluated at −6.7°, −1.1°, 4.4°, 10°, and 15.6°C and exposure periods of 4, 8, and 12 h against the metamorphic stages of the Angoumois grain moth, Sitotroga cerealella (Olivier), and Indianmeal moth, Plodia interpunctella (Hubner), in an 80% load of popcorn. The results indicated that the effectiveness of MeBr in controlling all stages of these 2 species declined rapidly as the temperature dropped below 4.4°C. The larval and pupal stages of the Angoumois grain moth were more tolerant than those of the Indianmeal moth to MeBr fumigation, the pupal stage of both species being the most tolerant.