Effcacy determination of commercial deltamethrin-treated storage bags on trogoderma granarium everts adults and larvae

Abstract

Trogoderma granarium Everts, the khapra beetle, is a serious stored product pest known to feed on >100 different products worldwide and is a major threat to global food security. Deltamethrin-treated storage bags are a resource that could be used to limit infestations during storage of grain in bags. We investigated the effcacy of deltamethrin-treated bags against T. granarium adults and larvae. Deltamethrin-treated and untreated packaging materials were afixed into the bottom of plastic Petri dishes (62 or 137 cm2) to create a bioassay arena. Adult T. granarium were exposed and observed to determine the time to knockdown and the subsequent mortality rate within 24 h. Adult T. granarium were knocked down in <60 min, and 100% of adults were knocked down or dead after 24 h. Trogoderma granarium larvae were exposed for 0.33, 1, 2, 3, or 4 d or continually exposed and monitored for larval death and adult emergence. Larvae exposed for 4 d had 50% mortality versus 97% if continually exposed. Utilizing this deltamethrin-treated packaging could cause disruptions in natural populations of T. granarium found in storage facilities, and the treated packaging is an effective tool that could be implemented into an integrated pest management program for bagged grain.