Problemi fitoiatrici e ambientali connessi all’introduzione di fitofagi e fitomizi alieni

Economic and environmental negative effects of alien pest species in Italy Biological invasions by alien pest species greatly increased in Europe and Italy, particularly during the last two or three decades. More than 500 alien insect Species are reported altogether for Italy, as mentioned on the European database-list published on the website of the DAISIE project (Delivering Alien Invasive species in Europe); more than 200 of those insects are registered from 1970 onwards. This means that the accession-rate, during a period of nearly 60 years, increased from about 0.5 species/year in the 1950s, to 1 species/year in the 1960s, 2 species/year in the 1980s, up to about 7-8 species/year during the last two decades. Trade is believed to be in most cases the main responsible of those alien accessions in the territory, to which touristic movements undoubtedly contribute. Quarantine measures adopted by legislative control organizations consequence, the risk of further accessions of alien species is believed to be very high for the same country. In addition, negative effects of alien species on agricultural crops, forestry and ornamental plants are shortly discussed, including economic and environmental impact, mostly due to chemical control as frequently used to reduce the invasive species populations. Integrated management and mostly classical biological measures are therefore recommended, whenever applicable, to control the newly introduced pests. In fact, the risk associated with exotic biological control agents, if conveniently managed, as shown by the long experience on the topic, is realistically absent or at least environmentally negligible in most cases.