RESUMO
Three standard foodstuff plastic packaging namely polyethylene (PE), polypropylene (PP), and polyvinylchloride (PVC) were evaluated for management of lesser grain borer Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Resistance parameters in packaging were recorded as punctures, holes, penetrations, sealing defects, and invasions with two thicknesses and tested for two lengths of time. Damages like punctures, holes and penetrations by both insects were more in PE packaging however R. dominica made more penetrations in PP than in PE. For both insects sealing defects and invasions were predominant in PVC than in others. Thickness did not affect significantly damage types but significantly more holes and penetrations by R. dominica were in less thickness. Punctures and holes by R. dominica were more after less time period but other damages in packaging were more after more time period. However for T. castaneum all sorts of damages were seen more after more time period. Overall categorization between two insects showed R. dominica made more penetrations and T. castaneum made more invasions compared with their counterparts. Pictures were taken under camera fitted microscope to magnify punctures and holes in different packaging and thicknesses. Insect mortality due to phosphine was more in PP and PE packaging and least in PVC packaging and thickness effect was marginal. T. castaneum mortality was significantly more after 48 h than after 24 h. Damages extent in packaging and fumigation results showed PP to be the best of three packaging materials to manage these insects.