Plectrura

Subfamily

Lamiinae

Diagnosis - adult

Body length: 8–13mm.
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 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 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 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 subquadratesubquadrate:
not quite a square
, 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
with tooth or spinespine:
a protuberance with an acute (sharp) distal end
, elytral color pattern present.
Legs: visible tarsomeres: 4, femora clavateclavate:
thickening gradually toward the tip
, protibial spurs: 2, tarsal claws simple.

Form moderate-sized, convex. Head with front short, transversetransverse:
broader than long
; genaegena:
the part of the cranium on each side below the eye
short, about as long as width of lower eye lobelobe:
a rounded projection or protuberence
; 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, shorter than body, scapescape:
the first proximal segment of the antenna
cylindricalcylindrical:
shaped like a cylinder, parallel sided
, short, third segment longer than scapescape:
the first proximal segment of the antenna
, fourth shorter than third. Pronotumpronotum:
the upper and dorsal part of the prothorax
about as broad as long, sides strongly, acutely tuberculate with large asperities before and behind tubercles; basebase:
the part of any appendage or structure that is nearest the body
broadly impressed; prosternum shallowly excavated, coxal cavities strongly angulate externally; mesosternummesosternum:
sternum of the mesothorax
with intercoxal process gradually arcuatearcuate:
arched or bow-like
; metasternum retracted. 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
basally gibbose; strongly convex; apicesapex:
end of any structure distad to the base
produced with long, blunt spines. Legs with femora moderately clavateclavate:
thickening gradually toward the tip
. Abdomen with first and last sternites broad (Linsley and Chemsak 1984).

Differential diagnosis

The acuminate apicesapex:
end of any structure distad to the base
of 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 large lateral asperities anterior and posterior to an acute tubercletubercle:
a small knoblike or rounded protuberance
of the pronotumpronotum:
the upper and dorsal part of the prothorax
make this genus distinctive.

Distribution

New World: western North America from Alaska to northern California

Old World: eastern Asia and Japan

Recorded host plants

New World: Thuja, Pseudotsuga, Tsuga, Acer, Alnus, Salix, Oplopanax, Rhamnus

Old World: Abies, Tsuga, Acer, Alnus, Cornus, Sorbus

Remarks

Two species, P. metallica in Old World under subgenus Phlyctidola. Both species with host records of conifers and broadleaf trees. Larvae under dead and wet bark.

Taxonomy

Plectrura Mannerheim, 1852, Bull. Soc. Nat. Moscou, 25 (1): 365

Phlyctidola Bates, 1884, The Journal of the Linnean Society of London. Zoology 18: 236