Xyleborinus

Type species

Bostrichus saxeseni Ratzeburg

Adapted from Wood 1982, p. 841-848

Diagnosis

Xyleborinus is distinguished from Xyleborus Eichhoff by the conical scutellumscutellum:
a shield-like bony plate or scale, as on the thorax of some insects
that does not fit into the suturalsutural:
pertaining to a suture such as the elytral suture or midline between the two wings
notch and is surrounded by a conspicuous pubescence.

Description

The length of females in this genus ranges from 1.4 to 3.5 mm, and they are 2.6 to 3.0 times as long as wide. The males are dwarfed and flightless. Their color is dark brown. The pronotumpronotum:
the upper or dorsal surface of the first thoracic segment
is usually longer than wide. The scutellumscutellum:
a shield-like bony plate or scale, as on the thorax of some insects
is conical, does not fit in the scutellar notch, and is surrounded by distinctive short tuft of hairs. The declivitydeclivity:
the apical portion of the beetle elytra that slopes downward
can either be concave, flat, or convex and is armedarmed:
having a sclerotized surface structure, giving a rough texture; may serve as defense
by a varying number of interstrial tuberclestubercles:
stiff, pointed, tapered processes on the surface of the integument, usually shorter than a spine
or rarely spines. The anterior margin of the compound eye is emarginateemarginate:
notched or indented
. The scapescape:
the first and basal segment of the insect's antennae
length in proportion to the funiclefunicle:
the antennal segments located between the scape and the club in some Coleoptera
is variable and is 5-segmented. The clubclub:
the apical segment of the insect antennae that is enlarged or thickened such that it is anatomically differentiated from the preceding segments
is obliquely truncateobliquely truncate:
pertaining to a structure abruptly and concavely cut
with none to two recurvedrecurved:
bent backward or downward as a smiley face
sutures on its posterior faceposterior face:
the side not visible when the club is elevated against the head or visible when the club is down and sensing a surface; it usually has no sutures
. They have a depresseddepressed:
a structure that is flattened or impressed
pregular region. The procoxaeprocoxae:
extra segment occasionally preceding coxa (hip joint) of the first or anterior pair of legs of arthropods
are contiguouscontiguous:
sharing an edge or boundary; touching
, if apparently narrowly separated, the intercoxal piece conspicuously notched longitudinally.

Distribution

Worldwide

World fauna

Number of species: 79, Native species: 2, Introduced species: 2

Established exotic species

Xyleborinus alni is present in Maine, New York, Pennsylvania, Maryland, Washington, and Oregon.

Xyleborinus saxeseni is present in Maine, New Hampshire, Massachusetts, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, West Virginia, North Carolina, South Carolina, Georgia, Florida, Ohio, Indiana, Kentucky, Tennesee, Alabama, Mississippi, Michigan, Illinois, Louisiana, Arkansas, Missouri, Iowa, Kansas, Texas, Utah, Arizona, California, Oregon, and Washington.

Hosts

Eugenia, Ochroma, Theobroma, Terminalia