Identification of the ambrosia beetle Xyleborinus saxesenii (Ratzeburg, 1837) (Coleoptera: Curculionidae: Scolytinae) from frass and adult DNA by TaqMan Probe real-time-PCR

A molecular tool has been set up for the unambiguous molecular identification of the ambrosia beetle, Xyleborinus saxesenii (Ratzeburg, 1837) (Coleoptera Curculionidae Scolytinae), the cosmopolitan fruit-tree pinhole borer, widely distributed in temperate regions of the five continents, where it infests a wide range of hardwoods and softwoods. The test was based on real-time PCR with TaqMan probe technology and was developed on whole insect bodies (adults) as well as on frass produced by the beetle. The test was shown to meet the criteria established by EPPO for the harmonization of molecular diagnostic methods. In particular, the test gave good results in terms of analytical specificity (inclusivity and exclusivity) and analytical sensitivity, and was fully repeatable and reproducible. Since X. saxesenii is one of the most commonly intercepted ambrosia beetles during phytosanitary controls worldwide, this practical diagnostic tool will be useful for its rapid identification of the beetle in biological material (frass, body fragments). The test can be useful in countries where X. saxesenii is a quarantine species, as well as in the EPPO region.