Vacuumized and Unvacuumized Polyethylene or Polyester Film Bags: Insect Survival and Resistance to Insect Penetration1

Abstract

Insect survival and reproduction were determined in vacuumized (V) and unvacuumized (UV) polyethylene (PE) or polyester (PET) bags of shelled peanuts. Tribolium castaneum (Herbst) larvae and adults survived and reproduced in V-PE (200 millibars) bags, and larvae survived, developed to adults, and reproduced in UV-PE bags. At 12 mo, live insects were found in UV-PE bags artificially infested with larvae and in V-PE bags initially infested with adults. Lasioderma serricorne (F.) and T. castaneum larvae matured to adults in V-PET and UV-PET bags, but no reproduction occurred when these bags were artificially infested with either adults or larvae. L. serrlcome adults reproduced in UV-PE as well as in V-PE bags. Cadra cautella (Walker) larvae matured and reproduced in UV-PE bags and matured in V-PE bags. C. cautella and L. serricorne penetrated the PE film. None of the three species tested reproduced in PET bags or penetrated these bags. PET bags exposed to external infestations were not penetrated. All V-PE bags were penetrated, whereas only 10% of the UV-PE bags were penetrated. The remaining intact bags developed low internal pressures during 12 mo of storage.