Bark and ambrosia beetles (Scolytinae) are the most successful group of invasive wood borers worldwide, and the most invasive among them are species in the tribe Xyleborini. This haplodiploid, highly inbred, fungus-farming group is represented by 30 non-native species in North America, of which at least five are serious pests. The few identification resources for Xyleborini that exist are becoming outdated due to new species arrivals and nomenclatural changes. Here we present a new comprehensive key to Xyleborini currently known from the continental United States. Compared to the previous key, the following species have been added to the North American fauna:Ambrosiodmusminor(Stebbing),Ambrosiophilusnodulosus(Eggers),AnisandrusmaicheKurentsov,Coptoboruspseudotenuis(Schedl),Cyclorhipidionfukiense(Eggers),DryocoetoidesreticulatusAtkinson,Dryoxylononoharaense(Murayama),Euwallaceainterjectus(Blandford),Xyleborinusandrewesi(Blandford),Xyleborinusartestriatus(Eichhoff),Xyleborinusoctiesdentatus(Murayama),XyleborusbispinatusEichhoff,XyleborusseriatusBlandford,XyleborusspinulosusBlandford, andXylosandrusamputatus(Blandford).

Ambrosia beetles of the Euwallacea fornicatus (Eichhoff, 1868) species complex are emerging tree pests, responsible for significant damage to orchards and ecosystems around the world. The species complex comprises seven described species, all of which are nearly identical. Given that the morphology-defined species boundaries have been ambiguous, historically, there has been much disagreement on species validity, which was compounded by the presumed loss of the type series of E. fornicatus. The species complex was recently reviewed using morphometrics to associate the type specimens to the clades delineated with molecular data under the assumption of the lost type series. We rediscovered a syntype of Xyleborus fornicatus, and reevaluated the species in the complex using morphometrics. We propose the following taxonomic changes to the species complex: Euwallacea fornicatus (=E. tapatapaoensis (Schedl, 1951); = E. whitfordiodendrus (Schedl, 1942)) syn. res.); E. fornicatior (Eggers, 1923) (=E. schultzei (Schedl, 1951) syn. nov.); E. kuroshio (Gomez and Hulcr, 2018) and E. perbrevis (Schedl, 1951) stat. res. These taxonomic changes shift the species name associated with the widely used common names for two taxa, namely: Euwallacea fornicatus should be used for the “Polyphagous Shot Hole Borer”, and E. perbrevis for the “Tea Shot Hole Borer clade a”. A lectotype is designated for X. fornicatus in order to stabilize the use of the name.

The ambrosia beetle Euwallacea fornicatus Eichhoff sensu lato is a complex of genetically divergent emerging pests responsible for damages to tree industries and ecosystems around the world. All lineages within the species complex are currently considered morphologically identical, presenting problems for their delineation and highlighting the shortcomings of species concepts based solely on type-specimen morphology. The objectives of this work were to 1) broaden the geographic sampling of the E. fornicatus complex in Asia, 2) reconstruct relationships between clades and populations, 3) find morphological characters or combinations of characters which are useful in delimiting the genetic lineages of the E. fornicatus species complex, and 4) propose taxonomic delimitation of species where morphology and phylogenetic identity correlate. Our integrated approach using molecular and morphological evidence suggests four clades that differ morphologically, but with overlap, therefore, cytochrome oxidase c subunit I (COI) barcoding remains necessary for assigning specimens to a clade. The following taxonomic changes are proposed: E. fornicatus (Eichhoff 1868) (= ‘Tea Shot Hole Borer Clade a’); E. fornicatior (Eggers 1923), stat. rev. (= ‘Tea Shot Hole Borer Clade b’); E. whitfordiodendrus (Schedl 1942), stat. rev. (= ‘Polyphagous Shot Hole Borer’); and E. kuroshio Gomez and Hulcr, sp. nov. (= ‘Kuroshio Shot Hole Borer’). This approach delivers a practical, evidence-based guidance for species delineation that can address overlapping variation in morphological characters of an emerging pest species complex.

The occurrence of the exotic “granulate ambrosia beetle” Xylosandrus crassiusculus (Motschulsky) in Argentina and Uruguay is reported for the first time, documenting expansion in South America. Morphological characters are provided to allow distinction of this species from other similar ambrosia beetles. Molecular identification was also done on the basis of the 5′ region of the mitochondrial cytochrome c oxidase I (COI) gene, obtained from a specimen from Argentina and compared with available “barcode” sequences in public databases. Phylogenetic analyses, via maximum likelihood and parsimony, were performed using COI sequences from 17 terminals, including 14 sequences of X. crassiusculus from different continents plus other Xylosandrus and Cnestus species as outgroups. Results from the sequence analyses confirm the identity of X. crassiusculus. The specimen from Argentina and the two sampled from United States showed no differences in their COI sequences. Further studies are needed, on the genetic variation through the native and introduced ranges of the granulate ambrosia beetle, to ascertain the source/s of origin of this biological invasion in the Americas. The present paper reports the expansion of this exotic species in South America into Argentina and Uruguay.

We present a reassessment of the diversity of bark and ambrosia beetles in Cuba. For the first time in decades, an official Cuban-American binational collaboration allowed us to re-visit all known entomology collections in Cuba, and collect in the field. There are at least 94 species of scolytine beetles in Cuba. We report a new species, Xylosandrus aurinegro Gomez & Hulcr (Coleoptera: Curculionidae), and 7 new species records, including the first genus record for Dryocoetoides Hopkins and Tricolus Blandford (both Coleoptera: Curculionidae) for the island. In terms of species with potential concern to the USA, we corroborate a subspecies of Ips calligraphus Wood & Bright (Coleoptera: Curculionidae) that acts as a pine pest in Cuba and is not yet present in North America.