Ability to penetrate through pasta packaging of the maize weevil, Sitophilus zeamais Motschulsky

The ability of maize weevil, Sitophilus zeamais Motschulsky, adults to penetrate pasta packages was studied. Infestations can occur during the storage process in manufacturing facilties, warehouses, general stores and retail shops. Sixteen different types of commercial pasta was tested: barley, buckwheat, durum wheat, five cereals (a mixture of durum wheat, barley, spelt, oat, and rye), kamut, corn, rice, spelt, barley and buckwheat, dietetic, egg pasta, gluten free, spelt and lentils, tricolour pasta (a mixture of semolina, tomato, and spinach), vitamin enriched, and whole wheat semolina. The pasta packages were divided into five categories depending on packaging characteristics: folded carton box (tube style) with end flaps tucked and glued, with a clear window of PP film; plastic pillow pouch with gussets, lap seal; plastic pillow pouch with gussets, fin seal; plastic pillow pouch with gussets, fin seal re-sealed; plastic pillow pouch without gussets, fin seal. Maize weevil adults were found inside packages of barley and buckwheat pasta, durum wheat pasta, egg pasta, five cereals pasta, kamut pasta, rice pasta, spelt pasta, spelt and lentils pasta, tricoloure pasta, vitamin enriched pasta, and whole wheat pasta. They entered into carton boxes and infested the pasta through openings not well sealed by glue. S. zeamais were also able to enter several types of plastic pasta packaging through large or enlarged air vent micro-holes present on polypropylene pasta packages. The results show that adult maize weevil prefer entry by already existing holes. New holes have never been detected but only a few signs of jaw attacks on some packaging. No infestation was observed inside packages of barley pasta, buckwheat pasta, corn pasta, dietetic pasta with fibre, or gluten free pasta.