Xyleborus

Taxonomy

Xyleborus Eichhoff, 1864: 37.

Synonyms

Anaeretus Dugès, 1888: 141. Hagedorn, 1910b: 98.

Progenius Blandford, 1896a: 20. Hagedorn, 1910b: 98.

Mesoscolytus Broun, 1904: 125. Beaver, 1998: 181.

Boroxylon Hopkins, 1915a: 58. Schedl, 1952c: 162.

Diagnosis

 1.9−3.9 mm long, 2.5−3.51 times as long as wide. Xyleborus is distinguished by a combination of homoplastic characters which include the scutellumscutellum:
a shield-like sclerotized plate located at the midpoint of the elytral base 
flush with elytraelytron:
the two sclerotized forewings of beetles that protect and cover the flight wings
and flat; mycangial tufts are absent; laterallateral:
pertaining to the side
margin of pronotumpronotum:
the dorsal surface of the thorax
obliquely costate; procoxae contiguous; pronotumpronotum:
the dorsal surface of the thorax
from dorsaldorsal:
of or relating to the upper surface; opposite of ventral
view rounded frontally (types 0, 2, 6, 7), rarely quadratequadrate:
square-like in shape
(type 4 in X. bidentatus); elytralelytral:
pertaining to the elytra
discdisc:
the flat central upper surface of any body part (e.g. pronotum and elytra)
longer than declivitydeclivity:
downward slope of either the pronotum or elytra
; elytralelytral:
pertaining to the elytra
discdisc:
the flat central upper surface of any body part (e.g. pronotum and elytra)
strial and interstrial punctures seriateseriate:
arranged or occurring in rows
; pronotalpronotal:
pertaining to the pronotum
discdisc:
the flat central upper surface of any body part (e.g. pronotum and elytra)
alutaceousalutaceous:
engraved fine reticulation
; posteriorposterior:
toward the rear end; opposite of anterior
face of the protibiaprotibia:
tibia of the first pair of legs
flat and unarmed; antennalantennal:
pertaining to the antennae
club typically obliquely truncateobliquely truncate:
nearly truncate but rounded not flat in lateral view
with segment 1 nearly covering the entireentire:
without marginal teeth or notches
posterior face (type 2), or flattened (type 3); antennalantennal:
pertaining to the antennae
funicle 4-segmented; and anterioranterior:
the front or forward; opposite of posterior
margin of pronotumpronotum:
the dorsal surface of the thorax
typically unarmed (serrations on a carinacarina:
an elevated ridge or keel, not necessarily high or acute
in X. bidentatus).

May be confused with

Cryptoxyleborus, Heteroborips, Planiculus, Stictodex, and Terminalinus 

Distribution

widespread throughout temperate and tropical regions of the world

Gallery system

The gallery system usually consists of irregularly branched tunnels, usually in one horizontal plane, but sometimes spreading into three dimensions, and without brood chambers. However, given the heterogeneity of the genus, it is not surprising that there are variations on this pattern. In some species, small brood chambers may be present. 

Remarks

Xyleborus is the largest genus and is in need of revision. Most Xyleborini species were originally described in Xyleborus, and revision of Xyleborus is ongoing on a regional basis.