Preharvest and postharvest losses in peanuts as impacted by insect infestation along the supply chain in Georgia State, USA

Abstract: The United States remains the top producer of peanuts (Arachis hypogaea L.) in
North America with an estimated annual production of 2.90 million metric tons (MT) of inshell peanuts with about 52 % produced in the state of Georgia. The current study evaluated
peanut losses to insects and associated quality deterioration across the supply chain from
preharvest to postharvest. The on-farm losses of peanuts assessed the species and abundance of subterranean insect pests of peanuts and estimated insect pest damage variables as well as
measuring the moisture content of peanuts during preharvest period in Georgia. Surveys were conducted during the 2022 production season on a total of twenty randomly selected peanut fields across northeastern and southern parts of Georgia. Pangaeus bilineatus (Say),
Elasmopalpus lignosellus (Zeller), and Diabrotica undecimpunctata Howardi were the most
abundant subterranean insect pests of peanuts (22.0 %, 33.1 %, and 36.3 %, respectively).
Postharvest losses were monitored by carrying out surveys in five conventional metal
warehouses (CMW) and thirteen flat storage facilities (FSF) to assess the spatial distribution
and abundance of storage insect pests, their damage variables, and associated aflatoxin
contaminants in peanuts. Peanuts were sampled monthly from December 2022 to July 2023.
A monoclonal antibody-based affinity chromatographic assay was used to determine the total
aflatoxin levels in peanut samples. Liposcelis spp., Cryptolestes ferrugineus (Stephens),
Tribolium castaneum (Herbst), Plodia interpunctella (Hb.), Lachesilla pedicularia (L.), Cadra cautella (Wlk.), Ahasverus advena (Waltl), and Ephestia elutella (Hb.) represented ~ 85.73 % of the total insects captured. Insect populations peaked between June and July. Insect-damaged kernels, weight loss, discolored kernels, loose-shelled kernels, moisture content, and aflatoxin levels were evaluated for both preharvest and postharvest samples. The observed high levels of storage insect pests, their high damage capabilities, and aflatoxin levels of infested peanuts require an improved IPM strategy in warehouses to ensure a sustainable and safe supply of peanuts in the USA.