Hylastes

Type species

Bostrichus ater Paykull

Adapted from Wood 1982, p. 93-107

Diagnosis

Hylastes is very similar to Hylurgops LeConte from which it is separated by having equally sized puncturespunctures:
a small impression on the hard outer parts of the insect body like those made by a needle
on the pronotumpronotum:
the upper or dorsal surface of the first thoracic segment
and usually shorter vestiturevestiture:
a surface covering of scales or setae on the body, wing, or other appendage
on the declivitydeclivity:
the apical portion of the beetle elytra that slopes downward
. Additionally, the pronotumpronotum:
the upper or dorsal surface of the first thoracic segment
is usually not constrictedconstricted:
contracted or compressed at places along the length of a structure
anteriorly as in Hylurgops.

Description

Species in this genus range from 2.1 to 6.0 mm in length and are approximately 2.6 to 3.2 times as long as wide. Their color varies from reddish brown to black. The pronotumpronotum:
the upper or dorsal surface of the first thoracic segment
is longer than wide and unarmedunarmed:
having no granules, teeth, tubercles, spines, or other protective structures
. The scutellumscutellum:
a shield-like bony plate or scale, as on the thorax of some insects
is small. The declivitydeclivity:
the apical portion of the beetle elytra that slopes downward
is convex and has granulesgranules:
a small grain-like elevation
or rarely small tuberclestubercles:
stiff, pointed, tapered processes on the surface of the integument, usually shorter than a spine
. The vestiturevestiture:
a surface covering of scales or setae on the body, wing, or other appendage
usually consists of short hair-like setaehair-like setae:
setae that are thin and similar to a hair
. The fronsfrons:
the upper anterior portion of the head capsule
usually has a median carinacarina:
a ridge or elevation of the cuticle
or a median groove above the epistomaepistoma:
the sclerotized region between the lower frontal area and the mouth parts
. The scapescape:
the first and basal segment of the insect's antennae
is usually as long as the 7-segmented funiclefunicle:
the antennal segments located between the scape and the club in some Coleoptera
. 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 ovateovate:
egg shaped, with the narrow end apically
with three straight suturessutures:
a seam or seam-like line of contact between two sclerites or hardened body parts immovably connected
. 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
.

Distribution

The Holarctic realmholarctic realm:
a faunal region comprising Europe, North Africa, Asia north of the Himalaya Mountains, and North America down to Mexico
with intrusions into the Neotropics south to Honduras.

World fauna

Number of species: 31, Native species: 13, Introduced species: 1

Established exotic species

Hylastes opacus is present in Maine, New Hampshire, Vermont, New York, West Virginia, and Oregon.

Hosts

Abies, Larix, Picea, Pinus, Pseudotstuga, Tsuga