Effect of Packaging Materials and Time Period for Damage in Packaging and Weight Loss in Packed Wheat Flour (Triticum aestivum L.) by Red Flour Beetles Tribolium castaneum Herbst (Coleoptera: Tenebrionidae)

Abstract

This study evaluates three popular loose plastic packaging namely polyethylene (PE), polypropylene (PP) and polyvinylchloride (PVC) for damage in packaging and weight loss in packed wheat flour by Tribolium castaneum Herbst (Coleoptera: Tenebriondiae) for three different time periods. The study lasted for three months and data was recorded three times with 30 day interval between data recordings to see damages in packaging, i.e., holes and penetrations made by beetles in packaging; number of beetles inside packages were counted to see their population growth after a given time period inside packed wheat flour and weight loss in wheat flour. Maximum holes by beetles were in polyethylene packaging, penetrations and numbers of beetles were more in polyethylene packaging type. Similarly weight loss in wheat flour was also more in polyethylene bags in contrast with other packaging materials used (P < 0.05). Effect of time period showed significantly more weight loss in wheat flour after 90 days than after 60 or 30 days (P < 0.05) however time period had non-significant effect on holes made by beetles into packaging and penetrations as well as numbers of beetles counted or their population growth after given time period in different packaging materials (P > 0.05). These results revealed that out of three packaging materials tested polyethylene was a susceptible packaging material because it had maximum number of holes and penetrations by insects into them. Similarly maximum weight loss occurred in polyethylene. Effect of time period showed non-significant effect on holes and insect penetrations into packaging materials. However more weight loss occurred after more time period than after less time period. These results are important and can be employed for integrated management of T. castaneum regarding packed foodstuffs i.e., wheat flour.