Emergenze fitosanitarie: aspetti entomologici

In Italy, despite the growing organization of plant health checks at borders, accidental introductions and the subsequent spread of pests (especially insects and mites) have become increasingly frequent over the recent decades. This is mainly due to the intensification of trade between different countries and the growing movement of goods and people in all parts of our planet, in addition to effects of climate change, which are facilitating the possibilities of adaptation in our environments by invasive species of tropical or subtropical origin, whose acclimatization would have been unimaginable a few decades ago. Some of the species which have been recently introduced in Italy forced to modify often deeply the strategies applied for crop protection. Many other species may be introduced in the near future and attempts to forecast their spread, mostly based on their current distribution, their ecological requirements and the intensity and frequency of trade with the areas of their current distribution, allow to draft and update lists of pests at risk of introduction. With reference to fruit trees, excluding very few species of mites and nematodes, most of the pests with risk of introduction in Italy belong to the insects, with special reference to Thysanoptera Thripidae, various families of Hemiptera (Cicadellidae, Liviidae, Triozidae, Aleyrodidae, Aphididae, Margarodidae, Pseudococcidae, Diaspididae), several Lepidoptera (Tortricidae, Carposinidae, Lasiocampidae, Pyralidae), many Tephritidae various Coleoptera and Diptera (especially longhorn beetle, but also Scarabaeidae, Chrysomelidae and Curculionidae). Among the fruit crops, citrus are generally the most susceptible and vulnerable crops which may acquire new phytophagous species of considerable economic significance, belonging to almost all the mentioned insect groups. For pome- and stone-fruits, harmful introductions could regard different Lepidoptera Tortricidae, some Diptera Tephritidae and beetles (Cerambycidae and Curculionidae), while introductions of Hemiptera Cicadellidae and Margarodidae are to be feared for grape. Worthy of attention are also tropical fruits (eg.: annona, avocado, guava, mango), whose cultivation is becoming ever more common in the southern Italian areas and which have a high potential risk of acquiring new exotic pests. After drafting the existing regulatory organization to contrast the introduction of alien pests, information on the mentioned insect groups are provided in the present paper. In conclusion, an analysis is provided of the strengths and weaknesses of the current system of phytosanitary controls aimed at reducing the risk of introduction and spread of harmful pests in Italy.