Colydiinae


Colydiinae is a subfamily of beetles, commonly known as cylindrical bark beetles. They have been treated historically as a family Colydiidae, but have been moved into the Zopheridae, where they constitute the bulk of the diversity of the newly expanded family, with about 140 genera worldwide. They are diverse for example in the Australian region, from where about 35 genera are known; in Europe, though, only 20 genera are found and many of these only with few species.
Little is known about the biology of these beetles. Most feed on fungi, others are carnivores and eat small arthropods such as bark beetles.

Systematics and taxonomy

Up to 9 tribes are accepted by various authors; others, however, synonymize some of these. Formerly, many additional tribes were recognized, but the Synchitini, for example, are today generally held to include a number of these tribes, and are even sometimes merged into the Colydiini.
The tribes are:
Delimitation of the Colydiinae against the other lineages of Zopheridae is usually unproblematic. The only significant case of dispute may be the Pycnomerini, which is a small lineage of Zopheridae incertae sedis and was formerly considered an independent family like the "Colydiidae". That treatment is almost certainly wrong, but whether these beetles should be placed in Zopheridae as an additional subfamily Pycnomerinae, or treated as tribe Pycnomerini - and if the latter, whether they are better included in the Colydiinae or the Zopherinae - is still disputed.

Selected genera

of cylindrical bark beetles include:
File:Colydium.elongatum.-.calwer.14.30.jpg|thumb|150px|right|Colydium elongatum of the tribe Colydiini
File:Orthocerus.clavicornis.-.calwer.14.22.jpg|thumb|150px|right|Orthocerus clavicornis of the disputed tribe Orthocerini
File:Synchita.variegata.-.calwer.14.28.jpg|thumb|150px|right|Synchita variegata of the disputed tribe Synchitini
The genera Pycnomerodes, Pycnomerus and Rhizonium are sometimes included in the Colydiinae too. Other authors consider the latter incertae sedis among the Tenebrionoidea; for the former two, see above. The species Xylolaemus sakhnovi was described in 2014 from a fossil preserved in Baltic amber, which dates to the Middle Eocene. This was the first species of Xylolaemus described from the fossil record. The extinct genus Paleoendeitoma, belonging to the extant tribe Synchitini is known from the Cenomanian aged Burmese amber of Myanmar.