Tetropium

Subfamily

Spondylidinae

Diagnosis - adult

Body length: 8–20mm. 
Eyes: eye interommatidial setaeseta:
a sclerotized hair-like projection of the cuticle
absent, eye divided—max one row of facets between, eye ommatidial density fine. 
AntennaeAntenna:
in larval and adult insects, paired segmented appendages, borne one on each side of the head, functioning as sense organs and bearing a large number of sensilla
: antennal length reaches between basebase:
the part of any appendage or structure that is nearest the body
and end of elytraelytron:
the leathery forewing of beetles, serving as a covering for the hind wings, commonly meeting opposite elytron in a straight line down the middle of the dorsum in repose
, antennal flagellar segments elongateelongate:
much longer than wide
, scapescape:
the first proximal segment of the antenna
smooth/punctate at apexapex:
end of any structure distad to the base
, antennal scapescape:
the first proximal segment of the antenna
≥ segment 3 or segment 3 > scapescape:
the first proximal segment of the antenna
. 
Pronotumpronotum:
the upper and dorsal part of the prothorax
: pronotumpronotum:
the upper and dorsal part of the prothorax
shape transversetransverse:
broader than long
, rarely subquadratesubquadrate:
not quite a square
, pronotumpronotum:
the upper and dorsal part of the prothorax
lateral armature absent. 
Prosternum: prosternal process not dilated at apexapex:
end of any structure distad to the base
, procoxal cavities open posteriorly. 
ElytraElytron:
the leathery forewing of beetles, serving as a covering for the hind wings, commonly meeting opposite elytron in a straight line down the middle of the dorsum in repose
: elytral length reaching or close to end of abdomen, elytral apicesapex:
end of any structure distad to the base
rounded or truncatetruncate:
cut off squarely at the tip
, elytral color black, brown, or reddish, elytral color pattern absent. 
Legs: visible tarsomeres: 4, femora robust, rarely slender, protibial spurs: 2, tarsal claws simple.

Head short; maxillary palpi a little longer than labial, last segment triangular; eyes finely faceted, divided into 2 separate lobes connected by a narrow, facetless line; antennaeantenna:
in larval and adult insects, paired segmented appendages, borne one on each side of the head, functioning as sense organs and bearing a large number of sensilla
rarely longer than body in male, attenuated toward apexapex:
end of any structure distad to the base
, eleventh segment appendiculateappendiculate:
bearing appendages
. Pronotumpronotum:
the upper and dorsal part of the prothorax
transverse, sides broadly rounded, disk flattened; prosternum flat or slightly concave anteriorly; mesonotum without stridulatory area, metepisterna moderately narrow throughout, not greatly widened anteriorly. ElytraElytron:
the leathery forewing of beetles, serving as a covering for the hind wings, commonly meeting opposite elytron in a straight line down the middle of the dorsum in repose
only moderately elongateelongate:
much longer than wide
, parallel-sided, a little convex; apicesapex:
end of any structure distad to the base
rounded. Legs short; femora compressed, fusiformfusiform:
spindle-shaped, i.e., broad at the middle and narrowing towards the ends
; anterior tibiaetibia:
the leg segment distal to the femur, proximal to the tarsus
with 2 spurs at apexapex:
end of any structure distad to the base
 (Chemsak 1996Chemsak 1996:
Chemsak, J.A. 1996. Illustrated Revision of the Cerambycidae of North America. Volume I. Parandrinae, Spondylidinae, Aseminae, Prioninae. Wolfsgarden Books. Burbank, California 1: i-x + 1-150, pls I-X. ISBN 1-885850-02-6.).

Similar genera

Megasemum, Nothorhina

Differential diagnosis

The divided eyes will separate Tetropium from other Spondylidinae except Atimia, which has closed procoxal cavities. Two tibial spurs, finely-faceted bald eyes, and open procoxal cavities will separate from look alikes.

Distribution

Nearctic south to Honduras; Palearctic

Recorded host plants

Pinaceae

Remarks

~27 spp (14 Old World + 13 New World)

Synonyms

Isarthron Dejean, 1835, Méquignon-Marvis Père & Fils, Paris, 2ème edition, livraison 4: 329

Callidium (Tetropium) Kirby, 1837

Criomorphus Mulsant, 1839

Taxonomy

Tetropium Kirby, 1837, In J. Richardson, Swainson & Kirby. Norwich, Josiah Fletcher 4: 174