Osservazioni sugli afidiEucallipterus tiliae(L.) eTinocallis platani(Kalt.) (Homoptera Callaphididae) dannosi al verde pubblico

During the period 1989-90, in the urban avenues of Sassari (North Sardinia), observations onEucallipterus tiliae(L.) andTinocallis platani(Kalt.) population fluctuations were carried out. These aphids, which infest rispectively limes and elms. caused the rain of copious quantities of sticky honeydew. Both species showed an annual alternation in population density, which caused the shift of the peack of abundance from late spring in the year of high abundance to the beginning of summer in that of low abundance. That seems to prove the occurrence, also for the populations living in mediterranean environment, of an inverse relationship between the densities of fundatrices and oviparae within each season.