Impatto dell'introduzione di insetti predatori esotici sulle "guilds" locali

The research theme concerned the undesirable effects of exotic predatory species introduced to control harmful species, and their impact and possible interaction on the local communities and the environment.Studies have been carried out on three different species of insects: 1)Harmonia axyridis(Coleoptera Coccinellidae) which have been assessed for ecological aspects such as interspecific predation and sperm survival in overwintering females. The results obtained show, in the first case, larvae belonging to the speciesChrysoperla carneaas a superior intraguild predator on aggressive invasive and large Multicolored Asian ladybirdH. axyridis larvaewhile, in the latter case, a very high survival ability of sperm over winter was recorded. 2) the Chestnut gall waspDryocosmus kuriphiluswhich has been evaluated for its degree of infestation and arthropod associated fauna in Sardinia. Results show a rapid parasitoid recruitment byD. kuriphilus. 3)Neuropteracrisopids belonging to the genusChrysoperla, for which a hybridization test between criptic species has been carried out. The results show that an absolute post-zygotic incompatibility does not exist among the species investigated, representing a risk factor to the species reared and sold in various countries around the world.Biological invasion by alien species is one of the factors that poses problems on biodiversity therefore understanding its mechanisms may allow us better use of biological control which is an essential component of sustainable agriculture.