Preliminary observations on the susceptibility of pseudo-cereals and other new grains for the European market to the attack of stored product beetles

Until a few years ago, pseudo-cereals and some other plants (originating either from Latin America or from Asia or Africa) of interest as food were almost unknown in Europe, but recently they have attracted the attention of researchers because of their growing diffusion in the agri-food industry. In the human diet, pseudo-cereals such as quinoa (Chenopodium quinoa Willdenow), amaranth (Amaranthus spp.) and buckwheat (Fagopyrum esculentum Moench) are appreciated for some properties including high nutritional values; similarly chia (Salvia hispanica L.), which is an oily seed, and teff (Eragrostis tef (Zuccagni) Trotter), which is instead a cereal, have interesting nutritional profiles. The grains of these plants can be consumed in the place of traditional cereals, as such or transformed into flour to obtain bread, pasta or other derivatives. Their cultivation is increasing in various countries of Europe, including Italy and, as for all (other) cereals, they are susceptible to attack by pests after harvest. This aspect cannot be ignored. Our laboratory research has investigated the susceptibility of pseudocereals, chia and teff to attack by some common stored-product beetles and moths known for their more or less marked polyphagy: Rhyzopertha dominica (F.) (Bostrichidae), Sitophilus granarius (L.) (Dryophthoridae), Tenebrio molitor (L.) (Tenebrionidae) and Plodia interpunctella (Hübner) (Pyralidae). Results revealed significant differences in the timescale and means of infestation and larval development: S. granarius and R. dominica grew only on buckwheat; P. interpunctella grew on all seeds except amaranth, with high larval trophic activity, but most larvae died between 60 and 90 days after the beginning of the infestation. T. molitor larval activity was observed on all the grains and the life cycle was not interrupted. This study, still underway, is a first step towards optimizing the storage methods of these new products and to understanding their main risks of infestation and ntamination.