Acanthocinus

Subfamily

Lamiinae

Diagnosis - adult

Body length: 7–28mm.
Eyes: eye interommatidial setaeseta:
a sclerotized hair-like projection of the cuticle
absent, eye deeply emarginateemarginate:
notched at the margin
> half width, 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 reaching/surpassing end of body, 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 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
, pronotumpronotum:
the upper and dorsal part of the prothorax
lateral armature acute spinespine:
a protuberance with an acute (sharp) distal end
.
Prosternum: prosternal process dilated at apexapex:
end of any structure distad to the base
, procoxal cavities closed 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 pattern present.
Legs: visible tarsomeres: 4, femora clavateclavate:
thickening gradually toward the tip
, protibial spurs: 2, tarsal claws simple.

Form moderate-sized to large, somewhat depressed. Head with front rather short, quadrate, slightly convex; clypeusclypeus:
that part of the insect head below the frons, to which the labrum is attached anteriorly
narrowly margined apically; eyes with lower lobes oblongoblong:
longer than broad
, usually longer than genaegena:
the part of the cranium on each side below the eye
, upper lobes widely separated above; genaegena:
the part of the cranium on each side below the eye
subparallel; antennal tubercles prominent, divergentdivergent:
spreading out from a common base
, bases contiguouscontiguous:
so near together as to touch
; 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
slender, 2-1/2 to four times longer than body in males, 1-1/2 to twice as long in females, segments four and/or five usually apically produced in males, segments three to at least five densely fimbriatefimbriate:
fringed with hairs of irregular length
beneath, scapescape:
the first proximal segment of the antenna
usually extending to lateral tubercles of pronotumpronotum:
the upper and dorsal part of the prothorax
, third segment longer than first, fourth subequal to third. Pronotumpronotum:
the upper and dorsal part of the prothorax
broader than long, sides moderately to strongly tuberculate behind middle, tubercles acutely spined at basal one-third; basal sulcussulcus:
groove with a purely functional origin
extending onto sides; disk bicallused behind apical margin; prosternum narrow, shallowly excavated, intercoxal process narrow, less than one-fourth as broad as coxal cavities; mesosternummesosternum:
sternum of the mesothorax
with intercoxal process about one-third as broad as coxal cavities, at least twice as broad as procoxal process; meta sternum with episternumepisternum:
the aspect of a thoracic pleuron dorsal to the coxal cavity and anterior to the pleural suture
subparallel, abruptly tapering 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
more than twice as long as broad, slighty tapering posteriorly to subparallel; disk vaguely to strongly tricostate, basebase:
the part of any appendage or structure that is nearest the body
feebly bigibbose; pubescence depressed, dense, often condensed into spots or vittaevitta:
a broad longitudinal stripe
along costae, erect hairs absent; apicesapex:
end of any structure distad to the base
rounded to subtruncatesubtruncate:
not quite cut off squarely at the tip
. Legs robust; femora clavateclavate:
thickening gradually toward the tip
, lacking erect hairs; tarsitarsus:
the leg segment distal to the apex of the tibia, bearing the pretarsus; consists of one to five tarsomeres (including pretarsus)
with first segment of hind pair longer than two following segments together, third segment cleft to basebase:
the part of any appendage or structure that is nearest the body
. Abdomen normally segmented in males, last segment elongateelongate:
much longer than wide
in females, terminated by a long, visible ovipositor (Linsley and Chemsak 1995).

Similar genera

Eutrichillus, Leiopus

Differential diagnosis

Members of Acanthocinus are easily recognized by the > 1.5x body length 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
, fimbriated antennal segments 3–5, lack of erect hairs on the 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
, and by the elongateelongate:
much longer than wide
ovipositor of the females. The terminal abdominal segment in males notched.

Distribution

Holarctic, Indomalaya

Recorded host plants

Old World: Pinaceae, Fagus sylvatica (A. xanthoneurus), Carpinus (A. elegans)

New World: Pinaceae

Remarks

25 spp. + 1 ssp. (Acanthocinus), 1 sp. (Acanthobatesianus). Almost all species are conifer feeders.

Synonyms

Astynomus Dejean, 1835

Aedilis Audinet-Serville, 1835

Graphisurus (Canonura) Casey, 1913, Memoirs on the Coleoptera, 4: 335

Graphisurus (Tylocerina) Casey, 1913, Memoirs on the Coleoptera, 4: 335

Neacanthocinus Dillon, 1956, Ann. Entomol. Soc. Amer., 49: 231

Taxonomy

Subgenus Acanthocinus Dejean, 1821, Catalogue de la Collection de Coléoptères de M. le Baron Dejean. p. 106 

Subgenus Acanthobatesianus Wallin, Kvamme & Lin, 2012: 19.