Host-plant relationships and life history of some Alebra species in Italy (Auchenorrhyncha: Cicadellidae)

Four Alebra species, A. albostriella, A. coryli, A. viridis, A. wahlbergi and their colour morphs, have been investigated on the following host-plants: Corylus avellana, Castanea sativa, Quercus cerris, e. robur, e. petraea and Acer campestre. Host-plant relationships of Alebra species showed an association between A. coryli and C. avellana, A. albostriella and Q. robur, A. wahlbergi and A. campestre. On the contrary on Q. cerris, Q. petraea and C. sativa two different species, A. albostriella and A. viridis, are coexisting. Alebra species showed different phenology and life histories: A. coryli and A. wahlbergi appeared univoltine,A. viridis bivoltine, and A. albostriella both uni- and bivoltine. The oviposition sites have been documented both for overwintering eggs, laid in the branches, and for summer eggs, laid in the main leaf nervation. Associations between nymphal and adult morphs are reported. A new morph, A. albostriella m. atrata,has been found on Q. robur.