Overwintering of the Mediterranean Fruit Fly (Diptera: Tephritidae) in Northern Greece

The overwintering potential of wild Mediterranean fruit fly, Ceratitis capitata (Wiedemann), within the northernmost zone of establishment of the fly was studied during 3 winters (1992-1995) in an orchard in northern Greece (40.3° north latitude). During late autumn and early winter of these years, larvae within various naturally infested host fruits, pupae, and adults were exposed outdoors to natural temperature conditions. Mortality rates were 100% for pupae and adults and greater than 60% for larvae subjected to the various treatments. The larvae that survived the treatments experienced high mortality in the subsequent pupal stage that was related to the duration of their developmental period; the earlier the larvae left the fruits during winter and spring the lower their survival. Females that emerged from March through May laid fertile eggs in late spring and early summer. Average longevity of adults was ≈90 d and average fecundity 246.7 eggs per female. These results suggest that under climatic conditions that permit boundary establishment a proportion of C. capitata larvae can overwinter and regenerate a population the following spring. The ecological importance of this finding for temperate, fruit-producing regions of the world is discussed.