Persistence and insecticidal evaluation of Inert-PMS formulation on wheat stored grains against Rhyzopertha dominica, Tribolium castaneum, Cryptolestes ferrugineus and Liposcelis paeta

Abstract

Experiment was conducted to determine the persistence and insecticidal efficacy of a new enhanced diatomaceous earth, Inert-PMS, in wheat against four stored grain insect pests [ Cryptolestes ferrugineus (Stephens), Liposcelis paeta Pearman, Rhyzopertha dominica (F.) and Tribolium castaneum (Herbst)] under the laboratory conditions at 50, 75 and 100 mg/kg, for intervals of 24 h, 4 and 7 d at 28oC and 65% RH. For persistence, Inert-PMS was applied to stored grain for 0, 30, 60, 90 and 120 d. The results demonstrated that adult mortality was directly proportional to the dose and exposure interval. While the efficacy remained constant up to 60 d, it fell after 90 and 120 d of storage. L. paeta and C. ferrugineus were the most susceptible to Inert-PMS (100% mortality) followed by R. dominica (81%) and T. castaneum (72%) at 75 mg/kg after 4 d. Inert-PMS also suppressed the reproduction at lower dose rates. Inert-PMS is an eco-friendly formulation that not only interferes with the growth and development of stored grain insects but is also cheap and free from ill effects.