Laricobius caucasicus Rost, 1893

Leschen, Richard A. B., 2011, World review of Laricobius (Coleoptera: Derodontidae), Zootaxa 2908, pp. 1-44 : 7

3. Laricobius caucasicus Rost, 1893

(figs 3)

Diagnosis. Body bicolored. Head dark; ocelli present. Prothorax transverse with well developed lateral carina and sides explanate. Pronotum light; posterior tooth absent. Scutellum dark. Surface of elytra not incurvate; elytral punctures not confluent. Epipleura light. Ventrites dark. Femora light. Tibiae light.

Description. Length 2.56 mm. Body bicolored, mostly dark tan above, head, scutellum, and ventrites black, hypomeron and epipleuron tan; antenna and legs tan with AI darker. Dorsal surfaces subglabrous. Head with ocelli; u-shaped furrow present; interocular distance about 4x the width of the eye; macropunctures ovate or fused, small to lineate and shallowly impressed, absent from central area of frons; micropunctures coarse; setation short, erect to suberect, length about half the width of the eye. Antenna with length of A3 about equal to A4, ratios 2.1:2.1:1.4:1.4:1.4:1.3:1.2:1.0:1.5:1.6:2.3; A11 not strongly asymmetrical. Prothorax transverse and dorsoventrally flattened, widest at middle, sides gradually narrowing anteriorly and more steeply convergent posteriorly; about 0.72 x as long as wide (pronotal length/greatest pronotal width = 0.72); depth = 0.24 mm; pronotum laterally broadly explanate with well developed lateral carina with a distinct sharp edge; anterior angle about 65° and not forming a tooth (may be obscured by setae); posterior angle indistinct and broadly rounded and without a short tooth; foveae visible in dorsal view; macropunctures ovate, deep, and well-separated; micropunctures coarse; setae erect and elongate, longer than half the width of eye. Elytra about 3.30 x as long as wide (elytral length/greatest elytral width = 3.30) and 3.41 x as long as pronotum (elytral length/pronotal length = 3.41); surface not incurvate at basal third; macropunctures not coalescing posteriorly to form grooves, separated by an average of 1 puncture diameter; micropunctures fine; microsculpture not visible; vestiture biseriate, mostly consisting of suberect setae, with scattered erect setae, elongate and about 2/3 the length of the eye.

Comments. Among the species that have an explanate pronotal margin, L. caucasicus is one of three species that has the head darker than the pronotum. It can be distinguished from L. laticollis and L. baoxingensis by the shape of the pronotum.

Rost (1893) mentions in the description that L. caucasicus that there is a shallow impression before the middle of the elytra; this feature is lacking in the specimen here examined.

Háva (2006) listed the type deposition of Rost’s specimen(s) of L. caucasicus as questionably in the MFNB, and queries for types to Berlin and Dresden where some of the Rost material was eventually deposited, either by direct deposition or by exchange ( Horn et al. 1990), did not yield specimens. A single specimen that is provisionally identified as L. caucasicus based on the original description and matching the distribution recorded in Rost (1893) is described here. I decided not to name this specimen as a neotype because the abdomen and hind legs of the female specimen (N. Havill, pers. com.) were removed for DNA work prior to this study.

Hosts. Plant: Abies nordmanniana (Steven) Spach.

Distribution. Georgia: Guria.

Material examined. 1, GEORGIA: Guria Province Bakhmaro 9 June 2007 Coll. M. Kenis ex. Abies nordmanniana , Laricobius caucasicus ?, Sample: Havill 07-66 ( YPM)