The first comprehensive diagnostic tools for pine sawflies (Hymenoptera: Diprionidae: Diprion)

Pine sawflies (Hymenoptera: Diprionidae: Diprion) are eruptive pests of pine and larch native to Eurasia, sometimes denuding whole forests. Many species show broad host preferences in their native range, and the introduced pine sawfly (Diprion similis) made a wide and unexpected leap to Eastern white pine upon its introduction to North America over a century ago. Given this precedent, further species of pine sawfly could unpredictably switch host pines upon introduction to North America, potentially devastating the pine timber industry—a sector that contributes 5% to the GDP of the United States. Despite the well-established economic significance of pine sawflies, there are no tools whatsoever for comprehensive identification of species within the genus Diprion; what few keys exist are regional and scattered across several languages. This limitation prevents discrimination of the introduced pine sawfly from its congeners, meaning that new invasive species cannot be detected. To remedy this, we have created the first global diagnostic tools for identification of all 12 pine sawfly species. We have completed Lucid matrix and dichotomous keys to both female and male pine sawfly adults, which will be made available to the public on IDTools, along with collation of bionomic data of all species. Moreover, we present the first molecular phylogeny for the pine sawflies, inferred under a Bayesian framework jointly from COI and 16S rDNA, providing preliminary context for species limits within Diprion.