Efficacy of Nitrogen against Stored Product Insects with Different Susceptibility Levels to Phosphine in Industrial Applications

Abstract

We carried out trials on the commercial applications of nitrogen in different industrial structures, using phosphine-susceptible and -resistant populations of three stored product beetle species, the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), and the saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). Twelve different trials were conducted in total, five in chambers and seven in large silos in Greece, following different temperatures and exposure times. In most of our trials, complete mortality was recorded, with the exception of two silos in which survival was recorded for T. castaneum and O. surinamensis, while S. oryzae was classified as the most susceptible species. Moreover, low or no progeny production was recorded for most of the trials. Our results indicate that nitrogen, through the reduction in the oxygen level, could be used for the control of stored product insects that are resistant to phosphine, and can be further utilized in resistance management strategies.