PENETRATION OF POLYVINYL-CHLORIDE AND POLYPROPYLENE PACKAGING FILMS BY EPHESTIA-CAUTELLA (LEPIDOPTERA, PYRALIDAE) AND PLODIA-INTERPUNCTELLA(LEPIDOPTERA, PYRALIDAE) LARVAE, AND TRIBOLIUM-CONFUSUM (COLEOPTERA, TENEBRIONIDAE) ADULTS

In response to a series of consumer complaints regarding insect contam ination of chocolate-based consumables, a study was undertaken to eval uate the barrier qualities of 2 flexible, transparent films against 1s t- and 5th-instar Ephestia cautella Walker and Plodia interpunctella ( Hubner) larvae, and Tribolium confusum Jacquelin du Val adults. It was found that the polypropylene film tested was resistant to penetration by each species, whereas a polyvinyl chloride film was only resistant to penetration by Ist instars of E. cautella. These results are discu ssed in the context of previous studies examining insect penetration o f packaging materials, and with regard to the utility of categorizing insect pests of packaged goods as either invaders or penetrators. It i s recommended that the confectioner in question investigate the feasib ility of packaging products with a film that offers higher resistance against insect pests than the polyvinyl chloride film.