First record of an invasive fruit fly belonging to Bactrocera dorsalis complex (Diptera: Tephritidae) in Europe

Abstract: Emerging pests are increasingly threatening fruit orchard health across the Mediterraneanarea. Tephritidae, representing serious threats for Europe, are numerous, and the fruit flies Bactrocerazonata and those belonging to Bactrocera dorsalis complex are among the most alarming species.These species are highly polyphagous and B. zonata has already spread to some Mediterraneancountries. Due to these ongoing threats, in the Campania Region (southern Italy), a surveywith traps and infested fruits analysis was performed with the aim of detecting the presence ofspecies of Bactrocera dorsalis complex. In two mixed fruit-trees fields, some adults belonging toa species of Bactrocera were captured in traps baited with the highly attractive male lure (methyleugenol). They were distinguished from similar-looking Bactrocera spp. by morphological andmolecular comparative analyses. Considering the existing morphological keys, specimens weretentatively identified as B. dorsalis but molecular characterization with COI split them into two clades.Some specimens were grouped with B. dorsalis similar to B. kandiensis and B. kandiensis and othersin a clade including B. dorsalis and B. invadens (syn. B. dorsalis). ITS1 sequences instead confirmedmorphological identification. The integrative approach allowed identifying all the specimens collectedas belonging to the B. dorsalis complex. This finding represents the first field interception in Europe ofa member of one of the most dangerous groups of fruit flies.