Efficacy determination of commercial deltamethrin treated storage bags on Trogoderma granarium Everts adults and larvae

Authors: Scheff, Deanna; Arthur, Franklin; MYERS, SCOTT - Animal And Plant Health Inspection Service (APHIS); DOMINGUE, MICHAEL - Kansas State University

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2020
Publication Date: 6/9/2020
Citation: Scheff, D.S., Arthur, F.H., Myers, S.W., Domingue, M.J. 2020. Efficacy determination of commercial deltamethrin treated storage bags on Trogoderma granarium Everts adults and larvae. Agronomy. 10:814. https://doi.org/10.3390/agronomy10060814.
DOI: https://doi.org/10.3390/agronomy10060814

Interpretive Summary: The khapra beetle is a highly destructive stored product insect that can feed on >100 different products worldwide and is a major threat to global food security. In many countries around the world, grain is often stored in large bags in warehouses, where it is susceptible to infestation by the khapra beetle. Long-lasting deltamethrin treated storage bags are a resource that could be used to limit infestations during storage of grain in bags, but its efficacy on khapra beetle adults and larvae have not been determined. Adult khapra beetles were knocked down on their backs and unable to move after less than 60 minutes of exposure on the treated packaging material. Khapra beetle larvae were highly susceptible to the deltamethrin treated packaging as well. A short 8 h exposure to the packaging resulted in 15% of exposed larvae dying and for larvae that were continually held on the treated bags there was ~97% mortality. The commercial deltamethrin treated packaging material was highly effective against adults and larvae of the khapra beetle suggesting it could be used as a part of an insect management program for bagged grain during storage and transport. This packaging could aid in preventing the transportation of khapra beetles and help prevent this invasive species of insect from spreading globally.

Technical Abstract: Trogoderma granarium Everts, 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 efficacy of the treated bags against T. granarium adults and larvae. Deltamethrin treated and untreated packaging material were affixed into the bottom of a plastic Petri dishes (62 or 137 cm2) to create a bioassay arena. Adult T. granarium were exposed and observed to determine time to knockdown and the subsequent mortality rate within 24 hr. 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, 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 treated packaging could cause disruptions in natural populations of T. granarium found in storage facilities and is an effective tool that could be implemented into an integrated pest management program for bagged grain.