Monitoring medfly adult populations in Central Greece

Abstract

Monitoring adult Medfly populations and their fluctuations, accompanied with fruit sampling to characterize their overwintering habitats is a crucial process toward enlightening our knowledge on its bio-ecology.
In 2020-2021 we monitored Ceratitis capitata (Cc) adult populations at the project’s 7.2-hectare pilot site, consisting of a mixture of hosts (pomes, prunes, citrus, loquats etc). Four types of commercial traps were established and dispersed in groups of 4 in 2 organic and 1 conventional orchard. McPhail, Decis, Tephri and Jackson traps were used and baited with trimedlure, biolure and other commercial attractants. Wet traps were filled with a 10% propylene-glycol solution to preserve dead insects. All traps were appropriately named, labeled and GPS-marked, and inspected weekly/biweekly (On/Off-season, respectively).
Our traps captured aprox. 37.500 flies until end of July 2021. Captures gradually started increasing after mid-June 2020-2021, with the McPhail type being the most efficient, followed by Decis, Tephri and Jackson. Later, captures peaked in late August and mid-October, while populations gradually decreased and vanished in early Jan. 2021. Seasonal and spatial population fluctuations of the 5 groups of traps separately revealed different patterns. Interestingly, Decis/Tephri traps peaked earlier than other traps, while McPhail captured the first peaking populations in the buffer zone of our Pilot experiment. Overall, commercial dry-type traps are recommended as efficient and easy-to-service in the field, while the role of buffer zone traps in marginal hosts and their proper establishment timing in monitored areas must be further investigated, as it appears to be crucial for the whole process.