Molecular and morphological identification of the invading Xylosandrus compactus (Coleoptera: Curculionidae: Scolytinae) and novel host plant records for Türkiye

The polyphagous invasive pest Xylosandrus compactus (Eichhoff) (Coleoptera: Curculionidae: Scolytinae) has recently been reported in Türkiye. This species causes economic losses for woody ornamental and agricultural plants and forest trees in the lands where it invaded and settled. It should be considered that this pest has a pretty high rate of spread, and its control relies on accurate identification. This species could be distinguished from other ambrosia beetles using both morphological and molecular characteristics provided by the present study. The mtDNA gene region from some specimens collected in Türkiye was used for molecular identification and compared to "barcode" sequences already present in NCBI databases. COI sequences from X. compactus individuals obtained from eight distinct host plant species were used in phylogenetic analysis. More research into the genetic diversity of this ambrosia beetle's native and introduced areas is required to understand the origin of this biological invasion in Türkiye. Since its definition in Türkiye, X. compactus has been detected in 32 host plant species, and this study has increased that number to 40 by identifying eight new host plant species. Except Hydrangea macrophylla (Thunb.) Ser. and Fraxinus ornus L., six new species have been added to the world host plant species list for X. compactus.