Cryphalini Classification

Johnson, Andrew J., Hulcr, Jiri, Knížek, Miloš, Atkinson, Thomas H., Mandelshtam, Michail Yu., Smith, Sarah M., Cognato, Anthony I., Park, Sangwook, Li, You & Jordal, Bjarte H., 2020, Revision of the Bark Beetle Genera Within the Former Cryphalini (Curculionidae: Scolytinae), Insect Systematics and Diversity 4 (3), No. 1, pp. 1-81 : 4-5

History of Cryphalini Classification

The first mention of Cryphalini as a group name was by Lindemann in 1877. The group-concept was much broader, including Pityophthorus Eichhoff, 1864 , Hypoborus Erichson, 1836 , Hylocurus Eichhoff, 1872 , and Xyloctonus Eichhoff, 1872 , all of which are currently placed in separate tribes.

Eichhoff described many of the contemporary genera, plus several which are now junior synonyms ( Eichhoff 1878a). Most contemporary Cryphalini genera were classified in ‘Cryphalidae’ which was a much narrower concept than previously described, containing the known Cryphalini genera (except Eidophelus Eichhoff, 1876 ) plus Hypoborus and Liparthrum Wollaston, 1854 (Hypoborini) and what is now the genus Pityoborus Blackman, 1922 (Corthylini) . Other groups, such as contemporary Micracidini LeConte, 1876 and Xyloctonini Eichhoff, 1878 , were explicitly described as different tribes.

This approximate group concept of Cryphalini remained until Hopkins presented a major reclassification of Scolytinae in 1915, with a group ‘Cryphalinae’ in an even broader sense including the contemporary tribes Xyleborini and some genera in the current Dryocoetini Lindemann, 1877 and Corthylini LeConte, 1876 . Most of the contemporary Cryphalini are contained in Hopkins ‘Division I, Subdivision A’, a group described based on the type of vestiture (‘with scales, rarely with hairs’) and the pattern of asperities along the anterior margin of the pronotum. The characters used to describe and diagnose the genera within the Cryphalini include the presence of distinct elytral strial punctures, the shape of the lateral margins of the pronotum, the degree to which the pronotum was produced, the apex of the elytra, and most importantly, the morphology of the antennae. Eidophelus was considered in a different subdivision with Dendroterus Blandford, 1904 and some other genera now placed in Dryocoetini .

Balachowsky (1949) presented a clarified classification of bark beetles which reflects most contemporary tribes. While restricted to the fauna of France, it clearly described Cryphalini as different from Hypoborini . Wood (1954) evaluated the North American Cryphalini genera and species, representing the contemporary scope of the tribe for the region. Two additional genera from East Asia were described by Nobuchi (1981), inferred partly by new sets of characters from the proventriculus ( Nobuchi 1969). While these alone enabled identification of most scolytine genera, they were not widely adopted as a diagnostic set of characters.

Schedl was a major contributor to Cryphalini systematics. While very prolific in describing new species, his classification of Cryphalini did not settle any of the considerable confusion and his nomenclatural practices were not consistently valid (see Wood and Bright 1992). Schedl described five genera in the contemporary Cryphalini , but four of these are now regarded as junior synonyms.

The most recent treatment of Cryphalini was Wood’s (1986a) review of all scolytine tribes and genera. In this review, Cryphalini was diagnosed based on the combination of the ascending costal margin of the elytra, by the base of the elytra that is unarmed (or rarely armed with a continuous line, not crenulations), by the declivous (steeply sloped) pronotum usually armed with serrations and asperities, by the concealed head when viewed dorsally, by the eye that is ‘usually’ entire and ‘less commonly emarginated’, by the antennal funicle with no more than five segments, by the antennal club which is ‘strongly flattened’ and never truncate, by the lateral margins of the pro- and mesotibiae armed with denticles, and by the metanepisternum which has a posterior margin concealed by the elytron.

Wood and Bright brought significant order to the chaos of the classification of Scolytinae as a whole, including Cryphalini . Many genera were synonymized, and a small number was described. Their compilation of the catalogs ( Wood and Bright 1987; Wood and Bright, 1992) is a milestone in scolytine systematics and provides a very useful starting point for taxonomic reviews. Allothenemus Bright and Torres, 2006 was subsequently described. During the final stages of this manuscript preparation, four further genera were described in Cryphalini : Atomothenemus Bright, 2019, Microsomus Bright, 2019 , Pygmaeoborus Bright, 2019, and Trypolepis Bright, 2019.