Considerations

Bright, Donald E., 2014, A Catalog of Scolytidae and Platypodidae (Coleoptera), Supplement 3 (2000 - 2010), with notes on subfamily and tribal reclassifications, Insecta Mundi 2014 (356), pp. 1-336 : 8-9

Subfamily Considerations

Wood (1978) presented a reclassification of the subfamilies and tribes of the Scolytidae . In that study, he placed the more than 6000 species of Scolytidae into two subfamilies and 25 tribes. This classification has been followed by all subsequent authors and has never been seriously challenged. However, this arrangement resulted in the recognition of extremely polyphyletic and/or paraphyletic taxa. The ultimate goal of phylogenetic systematics is the development and recognition of monophyletic lineages. As stated above, I herein recognize 13, supposedly monophyletic, subfamilies.

An outline of the subfamilies and their included tribe(s) is presented in the Table of Contents. A few additional comments are made below. A more complete discussion of the higher classification is being prepared and will be presented later.

HYLESININAE : This is one of the largest subfamilies and contains 12 tribes. One of these tribes, the Pachycotini , is designated as new herein.

HYORRHYNCHINI : This subfamily contains only one, very unique tribe which contains only three genera and 16 species. The group is an isolated, relict taxon that is confined to the region from India to China and Southeast Asia ( Beaver and Gebhardt 2004) and is not related to any currently recognized subfamily.

SCOLYTINAE : This subfamily contains two tribes.

HEXACOLINAE : This subfamily contains one tribe. Hexacolini is a newly restored name for the Ctenophorini ( Alonso-Zarazaga and Lyal 2009) .

CYLINDROBROTINAE : This subfamily is newly designated herein for the extinct genus Cy lindrobrotus Kirejtshuk et al. 2009. This genus was described for an early Cretaceous Lebanese amber specimen which displays a unique combination of archaic and advanced characters. The authors erected a new tribe and a new genus for the specimen; I have placed this taxon in a new subfamily.

SCOLYTOPLATYPODINAE : This subfamily contains only one tribe and one genus, Scolytoplatypus Blandford. It does not appear to be related to any present-day genus and is evidently a relict taxon of an extinct group.

CACTOPININAE : This subfamily contains only the genus Cactopinus Schwarz , the unique “horned bark beetle” genus. It is also only remotely related, if at all, to any known taxon.

CARPHODICTICINAE : This taxon has been moved back and forth between the Scolytidae and the Platypodidae . The latest position, by Alonzo-Zarazaga and Lyal (2009), places it in the Scolytidae and that position is followed here. The subfamily contains only five species.

MICRACIDINAE : This subfamily may actually be polyphyletic, but the divisions are not clear. Wood (1986) recognizes three distinct groups of genera within this taxon. I prefer, for the present, to consider the subfamily as consisting of one tribe, containing about 16 genera. The group is only remotely related to other subfamily groups.

CRYPTURGINAE . This subfamily contains one tribe that I had originally included in the Ipinae . Further reflections have convinced me that the tribe Crypturgini is not closely related to the other tribes in the Ipinae and should be considered a monophyletic taxon that represents a distinct subfamily. The subfamily contains one tribe with six genera.

IPINAE : In number of species, this is the largest subfamily, containing six tribes and many genera and species. It appears to be a compact group of related tribes.

CRYPHALINAE : This is a large subfamily that contains 25 genera ( Alonso-Zarazaga and Lyal 2009), all within a single tribe. Because of the large number of species and the evident variability, this subfamily may be polyphyletic although distinct divisions are not evident at the present time. The relationships of this subfamily are uncertain, but it does not appear to be closely related to any recognized subfamily.

CORTHYLINAE : This is another large subfamily that presently contains two tribes, each unique by their habits. The Pityophthorini are all true bark beetles, living on the phloem-cambium interface under the bark of infested plant material. The Corthylini are all ambrosia beetles, boring deep into the xylem layer of infested plant material. A few exceptions to this division are noted, but other morphological characters clearly delimit the tribes.

Molecular studies ( Sequeira et al. 2000, Farrell et al. 2001, Jordal et al. 2011) have indicated that some of the above tribes (and possibly subfamilies) are not monophyletic and further modifications of the classification are to be expected in the future.