Susceptibility of plastic packages to insect pests attacks

Packaging represents the ultimate defence of pasta producers against insect pests; even if the product comes out uncontaminated from the production line, this does not guarantee that it will reach the consumer in the same condition. The ability of some pests to pierce different plastic material is well known: insects are attracted by odors, therefore it is necessary to take in consideration the barrier properties to volatile compounds, Pasta packages are characterized by numerous pinholes which are mechanically produced to avoid having swollen bags after sealing: these pre-existing holes are often exploited by most pests as a preferential entrance to packages, and they are detected by insects by following the outflow of attractive odors. Packaging, therefore, represents a critical point in the quality preservation of packed pasta. Insect pests are commonly present in the production and storage environments, and their presence is favoured by unappropriate prevention measures. Common pests that affect pasta and starchy products usually belong to the genera: Tribolium, Sitophilus, Plodia and Rhyzopenha. The aim of the study was to evaluate the resistance to piercing of three plastic materials (polypropylene obtained with different processing techniques) by Tribolium spp>, Sitophilus spp, and Rhyzoperíha Dominica, and the relative ability of each pest to enter the packages. Two tests were carried out, the first one was aimed at evaluating the resistance of the plastic materials, the latter evaluated the ability of the species tested to enter pasta bags. Results confirmed the good resistance of PP to the penetration of insect pests, and highlighted the highest penetration ability of Sitophilus spp. The optimization and suitable design of the packaging system, which should consider the reduction of the hole diameter, would allow to reduce the risk of pests penetration.