OCCURRENCE OF IMMATURE STAGES OF OLIVE-PSYLLID EUPHYLLURA-PHILLYREAE (HOM, APHALARIDAE) IN PHILLYREA-LATIFOLIA AND OLEA-EUROPAEA IN COASTALNORTHERN GREECE

The occurence of immature stages of olive psylla, Euphyllura phillyrea e Foerster on olive trees (Olea europea) and Phillyrea media in northe rn Greece was studied during the years 1989/90. E. phillyreae, which i nfests olive trees and Phillyrea latifolia (P. media) in Greece, is un ivoltine and has an aestival-autumnal-hibernal reproductive diapause a s an adult. Immature stages and adults were collected from January 198 9 through December 1990 from two groups of P. latifolia, differing in vigour and time of blooming, and from olive trees. On olive, the first eggs were observed on early April. On Phillyrea, eggs were deposited much earlier than on olive. Egg laying was related to host phenology. As the eggs were laid during certain growth stages of the host plant, the various larval instars were also synchronized with certain growth stages of the plant. Therefore, the oviposition and the occurrence of larval stages differ between the three host plants tested and coincide with the proper stage of growth of each plant group. The period from oviposition to adult emergence was longest (3 months) on Phillyrea 1, shorter (2 months) on Phillyrea 2 and shortest (1.5 months) on olives.