Evaluation of Inert Dusts on Surface Applications and Factors That Maximize Their Insecticidal Efficacy

Abstract

We evaluated formulations of diatomaceous earth and zeolite originated from natural deposits from Greece as insecticides in concrete and steel surfaces for the control of three major beetle species of stored products: Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). The formulations were tested as dusts at 0.5 or 1 g/m2. Our results indicated that, in most of the cases tested, the inert materials caused 100% adult mortality for all three species, even at the lowest dose, after 7 days of exposure. At the same time, there were no considerable differences in the insecticidal effect of the formulations between concrete and steel surfaces. Among the species tested, R. dominica was the most susceptible, followed by S. oryzae and T. confusum. Our results indicate that natural resource-based inert silicaceous deposits could be used with success in stored product protection against insects at dose rates that are comparable with other commercially available inert material-based formulations.