Styloxus

Subfamily

Cerambycinae

Diagnosis - adult

Body length: 7–18mm. 
Eyes: eye interommatidial setaeseta:
a sclerotized hair-like projection of the cuticle
present, eye deeply emarginateemarginate:
notched at the margin
> half width, eye ommatidial density coarse. 
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
horned 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 longer than wide, 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 partial and revealing hind wings, elytral apicesapex:
end of any structure distad to the base
rounded or truncatetruncate:
cut off squarely at the tip
, elytral color black or brown, elytral color pattern absent. 
Legs: visible tarsomeres: 4, femora clavateclavate:
thickening gradually toward the tip
, protibial spurs: 2, tarsal claws simple.

Form elongateelongate:
much longer than wide
, slender, subcylindrical. Head deeply impressed between antennal tubercles; 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 throughout, nearly twice as long as body in male, about as long as body in female, second segment small, transversetransverse:
broader than long
, third segment longer than scapescape:
the first proximal segment of the antenna
or fourth segment; eyes large, contiguouscontiguous:
so near together as to touch
or narrowly separated in male, distinctly separated in female, deeply emarginateemarginate:
notched at the margin
but not divided; maxillary palpi truncatetruncate:
cut off squarely at the tip
at apexapex:
end of any structure distad to the base
. Pronotumpronotum:
the upper and dorsal part of the prothorax
distinctly longer than broad, sides parallel or a little obtuse; scutellumscutellum:
a small sclerite located directly posterior to the pronotum, bordered laterally by the elytra
nearly as long as broad, subtriangular, narrowly rounded 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
much longer than basal width, sometimes covering most of abdomen, gradually narrowing to apicesapex:
end of any structure distad to the base
, suturesuture:
groove marking the line of fusion of two formerly distinct plates; the line of junction of elytra
entire, apicesapex:
end of any structure distad to the base
narrowly separated, rounded. Legs slender, posterior femora clavateclavate:
thickening gradually toward the tip
; tibiaetibia:
the leg segment distal to the femur, proximal to the tarsus
longer than femora; tarsitarsus:
the leg segment distal to the apex of the tibia, bearing the pretarsus; consists of one to five tarsomeres (including pretarsus)
nearly 1/2 as long as tibiaetibia:
the leg segment distal to the femur, proximal to the tarsus
, slender, subcylindrical, first segment more than twice as long as broad, about as long as 2 following together. Abdomen elongateelongate:
much longer than wide
, cylindricalcylindrical:
shaped like a cylinder, parallel sided
, that of female with 5 visible sternites, fifth hairy and deeply, angularly excavated, fifth sternite of male broadly emarginateemarginate:
notched at the margin
, revealing sixth sternite (Linsley 1962Linsley 1962:
Linsley, E.G. 1962. The Cerambycidae of North America. Part III. Taxonomy and classification of the subfamily Cerambycinae, tribes Opsimini through Megaderini. University of California Publications in Entomology, Vol. 20. 188 pp.).

Similar genera

Methia, Pseudomethia

Differential diagnosis

The corneous (horned) scapescape:
the first proximal segment of the antenna
will differentiate from non-Methiini genera. Pseudomethia has the third antennal segment shorter than the scapescape:
the first proximal segment of the antenna
and lateral pronotal tubercles. The elongateelongate:
much longer than wide
pronotum that is parallel or convex laterally, large scapescape:
the first proximal segment of the antenna
horn, and the clavateclavate:
thickening gradually toward the tip
femora distinguish Styloxus from Methia.

Distribution

Nearctic: United States from Oregon to Texas

Recorded host plants

Juniperus spp., Cupressus spp.; Quercus agrifolia (S. fulleri)

Remarks

7 species. Conifers: S. bicolor. They are twig girdlers.

Synonyms

Idoemea Horn, 1880, Trans. Amer. Ent. Soc., 8: 137

Malthopia Casey, 1912, Memoirs on the Coleoptera, 3: 308

Taxonomy

Styloxus LeConte, 1873, Smithsonian Misc. Coll., 11 (264): 239