Uncovering hidden diversity within the Euwallacea fornicatus species complex in China

Accurate species delimitation is an important component of pest management. The Euwallacea fornicatus spe-cies complex (Coleoptera: Curculionidae: Scolytinae) includes a series of morphologically similar forest pests that cause huge economic losses both in invaded regions and in the native region. The current hypothesis about the species complex postulates the existence of four species: E. fornicatus (Eichhoff), E. fornicatior (Eggers), E. kuroshio Gomez and Hulcr, and E. perbrevis (Schedl). To test the current hypothesis and reveal the diversity in China, we explored the genetic diver-sity of the Euwallacea fornicatus complex using molecular approaches. Species and clades were delimited (using ABGD, bGMYC, mPTP and BP&P approaches) based on mitochondrial COI and 16S, and nuclear 18S-ITS1-5.8S, 28S and CAD. All specimens from continental China were E. fornicatus, consistently separating into three molecular taxonomic. Of the other species, E. perbrevis was recovered from Hainan. The distribution pattern and genetic diversity of these species con-tributes to the development of adequate control strategies since different species can cause different damage.