Thomas H. Atkinson

Morphology, Taxonomy, and Phylogenetics of Bark Beetles

This chapter summarizes the historical and contemporary taxonomy, phylogenetic relationships, morphological and molecular approaches, and information resources used in the classification of bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae). The chapter pays special attention to the description of methods, including details on morphological and molecular characters on which the current classification is based. Illustrations and a detailed glossary of representative groups will allow users to understand the morphology of bark beetles. Relationships are illustrated by an up-to-date consensus phylogenetic tree. Diversity of the group, as well as individual tribes and genera, are exhaustively tabulated for the first time. Controversies surrounding the evolutionary origins of bark beetles and ambiguities in their morphology and classification are also discussed.

First Records of Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae: Scolytinae) from South America, with Notes on Its Distribution and Spread in the New World

Xylosandrus crassiusculus (Motschulsky), the granulate ambrosia beetle, is presumably native to southern Asia. It has been introduced into tropical and subtropical areas of the World, including much of sub-Saharan Africa, parts of the New World (Anderson 1974; Wood 1982; Wood and Bright 1992; Kirkendall and Ødegaard 2007), and Europe (Kirkendall and Faccoli 2010). It was first detected in the New World in coastal South Carolina (Anderson 1974). It was reported from Costa Rica (1996) and Panama (2003) (Kirkendall and Ødegaard 2007) in what is most likely separate introduction events. The beetle is a serious economic pest in tree nurseries and transplanted orchard and ornamental trees wherever it is found (Browne 1961; Kovach and Gorsuch 1985; Atkinson et al. 1988; Ranger et al. 2015). Recently, we have found significant range extensions for this species in Central and South America. The records included here mainly come from a survey of Brazilian bark and ambrosia beetles (Flechtmann and collaborators). Over a period of more than 20 years, the senior author (alone or with collaborators) has run trapping studies over 12-month periods at sites throughout Brazil (Fig. 1), mostly using ethanol-baited flight intercept traps. These previous studies are particularly valuable because they help document sites where other ambrosia beetles were trapped with similar methods but X. crassiusculus was not found, allowing us to have more confidence in bracketing the introduction(s) of this species into Brazil and any subsequent spread. Additional new distribution records from Central America come from the revision of collections by the second author. Specimens cited

Two remarkable new species of Hypothenemus Westwood (Curculionidae: Scolytinae) from Southeastern USA

Two new Hypothenemus species found in southern and southeastern USA are described: Hypothenemus piaparolinae sp. n. and Hypothenemus subterrestris sp. n. The distribution and habits suggest these species are native and widely distributed, but elusive, and not recently arrived exotics. Both appear to have unusual biology: H. subterrestris appears to live in material on or in the ground, and H. piaparolinae has only been collected from the xylem of extensively rotten, fungus-filled twigs.

A new species, new synonymy and new records of Mexican and Central American Xyleborini (Coleoptera: Curculionidae: Scolytinae)

Coptoborus silviasalasi Atkinson, new species is described from Oaxaca, Mexico. New synonyms include: Dryocoetoides capucinus Eichhoff, 1869 (=monachus Blandford, 1898) and Taurodemus sharpi Blandford, 1898 (= sharpi lenis Wood, 1974). Significant new distribution records are given for Xyleborini from Mexico and Central America.

New Records of Scolytinae (Coleoptera: Curculionidae) from Argentina

The most recent checklist of Scolytinae from Argentina is that of Bright (2004), who included 72 species. This list was primarily based on the world catalog of Wood and Bright (1992). Wood (2007) included 142 species in his monograph of the group for South America. The most recent addition was that of Landi et al. (2017), who documented the presence of Xylosandrus crassiusculus (Motschulsky), an Old World species widely distributed in North and South America (Flechtmann and Atkinson 2016). As part of an effort to catalog the species of bark and ambrosia beetles from Argentina, we became aware of a number of new country and province records. These records are from recent field work by the first author and revision of material from collections by the second author. Nine species are reported from Argentina for the first time. Additional province records are added for another 13 species. Three additional genera are reported for the first time from Argentina, although the identity of the species has not yet been determined. Including records reported here, there are now 153 species from 51 genera known from the country. Although Wood’s (2007) treatment is the most recent, he did not consistently cite all previously published provincial records. In the following list, previously reported provinces and distribution summaries are based collectively on several publications that are not cited separately for the sake of simplicity (Schedl, 1938, 1939, 1951, 1952, 1958, 1975, 1979; Vianna 1964; Wood 2007; Atkinson 2018). In cases where there have been nomenclatorial changes since Wood (2007), the previous name or combination is indicated in parentheses. Collections. Specimens cited below are deposited in the following collections.

A new species of Cactopinus Schwarz from central Mexico (Coleoptera: Curculionidae: Scolytinae)

A new species in the genus Cactopinus Schwarz is described from central Mexico bringing the total of known species to 22.