Note sulla presenza di formiche (Hymenoptera Formicidae) in industrie alimentari

Notes on the presence of ants (Hymenoptera Formicidae) in food industries. - The presence of, and infestation by, ants [Hymenoptera Formicidae] in food industries and more generally in the buildings of the urban environment, can be counted as examples of hard-to-solve entomological issues, because control strategies have only temporary effects. The genera and species in question may differ depending on variables such as the geographic and environmental location of the factories, and the different types of foodstuffs and their processing. When planning prevention and control strategies, the peculiarity of these social insects must be borne in mind: they are characterized by remarkable biological plasticity, a heterogeneity of habitat choice and sometimes by a greater or lesser degree of synanthropy. The most commonly recurring genera of Formicidae referred to in the literature as pests in the food industry in Italy, due to their frequency or severity of infestation, are: Linepithema, Monomorium, Solenopsis, Tetramorium, Pheidole, Lasius. The ants found in food factories most frequently belong to the caste of “workers”, but sometimes many winged individuals are caught by light traps; this could be due to insufficient isolation from the outside, or sometimes to swarming taking place inside (not necessarily outside) the industry buildings, given the many possible nest locations (walls, crawlspaces, floors, wooden structures, electrical boxes, etc.). The observations made by us over the last fifteen years, besides confirming already consolidated knowledge, indicate that sometimes ants which are not typical for the food industry can be found in such an environment. Among these we note, quite unusually, the gen. Hypoponera, found in a factory in central Italy. Finally, the risk of passive introduction into Italy of foreign species due to intense traffic and international trade, should be considered.