Observations and dates of infestations of Empoasca decedens Paoli and Zygina flammigera (Fourcroy) (Homoptera, Typhlocibidae) on peaches in Campania.
Empoasca decedens and Zygina flammigera are the commonest leafhoppers infesting peach trees in Campania (southern Italy). Data to identify eggs and young stages of both species are given. E. decedens caused severe leaf damage (leaf curling) mainly on young plants and leaves. The percentage of infested shoots reached peaks of 54% (1989) and 80% (1990). Adults migrated into peach orchards in April-May, and reached their maximum density in late July after a slight decrease. Eggs were deposited, in general, singly in a wound made in the main leaf vein. The apical leaves of the youngest shoots and the medio-distal part of the leaf were the preferred sites for oviposition. The average number of young stages/shoot reached more than 2.5 individuals. The economic threshold was tentatively evaluated on 20-30% of infested shoots (100 shoots/ha on average) each with 1.5-2 individuals. For younger plants the threshold was estimated at 10-15% of infested shoots. Z. flammigera was very common, but was not as great a pest as E. decedens. The former was plasmophagous and caused silvering symptoms on infested leaves. Oviposition took place mainly in the marginal areas of the leaf, preferably in the basal and apical parts of the oldest leaves located at the bottom of the crown. Normally, there was 1 egg/oviposition. Eggs of Z. flammigera were heavily parasitized by Anagrus atomus. It was concluded that chemical control was required in some peach orchards against E. decedens.