Influence of Loose-Shell Kernels and Foreign Material on Insect Damage in Stored Peanuts

Abstract

Loose-shell kernels (LSK) and foreign material (FM) were added to, or removed from, farmers stock peanuts to produce combinations of 0% LSK-FM, 5% LSK-10% FM, and 10% LSK-20% FM. Peanuts were treated with either 20 ppm pirimiphos-methyl or distilled water, placed in a metal shed, and infested with almond moths, Cadra cautella (Walker), Indianmeal moths, Plodia interpunctella (Hubner), red flour beetles, Tribolium Castaneum (Herbst), merchant grain beetles, Oryzaephilus mercator (Faurel), and cigarette beetles, Lasioderma serricorne (F.). Samples were taken at 2, 4, 6, 9, and 12 mo after treatment. The number of insect-damaged kernels from cracked pods in untreated peanuts was ca. 20-30% higher in peanuts with 0% LSK-FM than in either of the other two LSK-FM combinations. The number of insect-damaged kernels was significantly lower in treated versus untreated peanuts, but percent damage was greater in peanuts with 0% LSK-FM. LSK from untreated peanuts had ca. 40-60% damage throughout the year. The number of live insects in untreated peanuts was greater in the 5% LSK-10% FM and 10% LSK-20% FM than in peanuts with 0% LSK-FM at 2 mo, but the number of insects in all three combinations declined until 12 mo.