Introductions of insect pests into Italy during the last 50 years
The insect pests introduced into Italy during the last fifty years (1945 to 1995) have been listed on the basis of bibliographic data. In this period, 115 insect species have been introduced (more than 2 species per year). When looking at the first twenty years (1945 to 1964), it appears that introductions were a rare event (only 12 species had been introduced). Starting from the decade 1965-1974, a remarkable increase in the number of introduced species is observed (6 species in the previous decade to 18). This increase is then even greater, as during the last 20 years, 84 new species have been introduced. The authors noted that this indeed reflects the great increase in commercial exchange, but probably also the fact that deeper studies are being made on the Italian fauna (leading to the discovery of new exotic species which may have been present for several years).
The introduced species are mainly pests of ornamentals, woody plants and citrus. The three orders accounting for most introductions are: Homoptera (76 % of the total number of introduced species), Coleoptera (10 %), Lepidoptera (7%). The majority of species came from America (36 %), Asia (25 %), Africa (17 %), Australia (7%).
In addition, several examples of introduction and spread of insect pests are given. Metcalfa pruinosa was detected in north eastern Italy in 1979, and has now colonized north Italy, central Italy, Sardegna. It is also recorded in France (1986), Switzerland and Slovenia (1993) (see EPPO RS 96/040). 11 insects of fruit trees and grapevine have been introduced, but only four have attained pest status; and they include Scaphoideus titanus (vector of grapevine flavescence dorée – EPPO A2 quarantine pest) and Rhagoletis completa (see EPPO RS 97/103). The introductions of Leptinotarsa decemlineata, Liriomyza huidobrensis (EPPO A2 quarantine pests) and Phyllocnistis citrella are also mentioned as important examples.
Sources
Pellizzari, G.; Dalla Montá, L. (1997) 1945-1995: Fifty years of incidental insect pest introductions to Italy.
Acta Phytopathologica et Entomologica Hungarica, 32(1-2), 171-183.