Phosphine Resistance in Insects Infesting Stored Peanuts in the Southeastern United States

Abstract
Field strains of red flour beetle, Tribolium castaneum (Herbst), almond moth, Cadra cautella (Walker), and Indianmeal moth, Plodia interpunctella (Hübner), were collected from peanut storage facilities in Georgia, Florida, and Alabama, and tested for resistance to phosphine. Treatment with a discriminating dose of phosphine indicated resistance in 8 of 23 strains of the red flour beetle, 3 of 18 strains of the almond moth, and 4 of 7 strains of the Indianmeal moth. Frequencies of phosphine resistance in these insects were low and probably did not contribute to control failures.