Efficacy of two novel insecticide-impregnated nets against four major stored product beetle species

The majority of long-lasting insecticide-incorporated nets use alpha-cypermethrin or deltamethrin after harvest. However, there is interest in including long-lasting insecticide nets in integrated pest management programs at food facilities with new active ingredients against stored product insects. In this study, two impregnated nets, one with etofenprox and one with permethrin, were tested against adults of four stored product insects, that is Prostephanus truncatus (Horn), Sitophilus zeamais Motschulsky, Tribolium castaneum (Herbst), and Sitophilus granarius (L.). Among the tested species, S. granarius was the most susceptible, while in most cases, there were no differences in the efficacy level between the two nets. Short exposures resulted in immediate knockdown of all species, while increasing exposure to the nets decreased knockdown but increased adult mortality. When all adults were removed from the treated substrate and were transferred to untreated dishes, previous exposure to both nets caused more than 90% of delayed mortality 3 or 7 d later for S. granarius and S. zeamais. Our data underline the efficacy of impregnated nets with new active ingredients and their potentials for further use in stored product protection strategies.