Invasion of Ceratitis capitata W. (Diptera, Tephritidae) from coastal to inland areas of Dalmatia region of Croatia: E-traps as an improved detection tool

Abstract

The Mediterranean fruit fly, Ceratitis capitata (Wied.), is a pest of great economic importance worldwide and in the coastal areas of Croatia. After the introduction and establishment of this pest in the coastal areas, there was no evidence of its spread to the less favourable neighbouring areas north of the coast. In order to investigate the spread of C. capitata to inland areas, a grid of conventional and electronic traps was established in 25 sites, at the edges of the pests’ current distribution, where populations expand and contract their range seasonally. For each site, data was collected on host species, habitat description, elevation and geographic location using a GPS. Two types of conventional traps were used to monitor C. capitata population: Tephri traps baited with 3C lure (tri-methyl amine, putrescine, and ammonium acetate) and Jackson traps baited with trimedlure. A new improved detection tool, e-traps, was developed under the EU Horizon 2020 project “Fruit flies In Silico Pest Management (FF-IPM)”. This improved method of fruit fly detection and monitoring was incorporated into a conventional network of traps. The e-traps were set using locally purchased SIM cards and batteries. A total of 12 e-traps were successfully set at six sites (two e-traps per site, one with 3C bait and one with trimedlure) in trapping stations adjacent to existing Tephri traps and Jackson traps. Traps were inspected at weekly intervals and the number of males and females of C. capitata and other non-target insects were recorded. Surveys conducted in 2020 and 2021 showed that C. capitata has spread and invaded large parts of the sub-Mediterranean inland area of Split – Dalmatia and Šibenik – Knin counties. The e-traps provided a good early warning of the presence of the C. capitata in costal and invaded areas.