Nebria Erwinebria Kavanaugh,, 2021

Kavanaugh, David H., Maddison, David R., Simison, W. Brian, Schoville, Sean D., Schmidt, Joachim, Faille, Arnaud, Moore, Wendy, Pflug, James M., Archambeault, Sophie L., Hoang, Tinya & Chen, Jei-Ying, 2021, Phylogeny of the supertribe Nebriitae (Coleoptera, Carabidae) based on analyses of DNA sequence data, ZooKeys 1044, pp. 41-152 : 41

Subgenus Nebria Erwinebria Kavanaugh, subgen. nov.

Nebria gregaria = " Nebria gregaria group" sensu Lindroth 1961

Reductonebria Shilenkov, 1975 (in part); = " Nebria sahlbergi " + " Nebria gregaria " groups sensu Ledoux and Roux 2005

Type species.

Nebria sahlbergii Fischer von Waldheim, 1828:254, by present designation.

Diagnosis.

Body size small to medium, SBL = 7.1 to 11.7 mm. Head width medium to slightly broadened, not constricted behind eyes; vertex with a pair of paramedial pale spots and a single pair of supraorbital setae. Eyes slightly reduced to moderate in size, moderately to markedly convex. Antennal scape with one (two in very few specimens) subapicodorsal seta; antennomeres 3 and 4 not laterally compressed, without extra setae. Labrum with three pairs of apical setae. Maxillary stipes typical for genus, with setae inserted flush on smooth surface. Penultimate labial palpomere with three setae. Pronotum with midlateral setae absent, a single pair of basolateral setae present. Elytral intervals smooth, without macrosculpture, interval 3 with three to eight or more setiferous pores, intervals 5 and 7 without setiferous pores, interval 3 not or only faintly catenate, intervals 5 and 7 not catenate. Hindwings full-sized or slightly to markedly reduced in size. Metepisterna smooth or faintly punctulate. Protarsomeres 1-3 expanded in males; mesotarsomeres 2-4 longer than their apical width; tarsi dorsally glabrous or with a few fine setae. Abdominal sternites IV-VI with two to four pairs of posterior paramedial setae, without paralateral setae. Median lobe of male aedeagus sclerotized dorsally at least to midlength on shaft, moderately to markedly deflected right in dorsal aspect; basal bulb expanded, quadrate, broadly open basally and closed dorsally, without a sagittal aileron present at base or with only a lightly sclerotized collar; mid-shaft parallel-sided or slightly to moderately narrowed basally in lateral aspect, slightly compressed in cross-section, with right lateral face unmodified; apical orifice markedly to extremely deflected right. Right paramere slender and moderately long. Female valvifers with vestiture (a few specimens of some species without vestiture); gonopods VIII fused to dorsomedial bases of gonocoxae; gonocoxae with ventral diagonal row of setiform setae and mediodorsal row of setae present. Bursa copulatrix without dorsal sclerites in vestibular chamber and with longitudinal axis of the bursa moderately to markedly sigmoid dorsally in lateral aspect; spermathecal chamber broadly cordate in dorsal aspect, without (in Nebria lyelli Van Dyke, 1925 and Nebria quileute Kavanaugh, 1979) or with a small to large midline sclerotized dorsal plate, insemination duct not sclerotized; spermathecal duct medium-length to slightly long, uniform in diameter throughout or nearly so, inserted basodorsally on spermathecal chamber; spermathecal reservoir of medium length.

Etymology.

The subgeneric epithet is a noun of feminine gender and a combination of the surname of Terry L. Erwin, in whose honor we name this subgenus, and the genus name, Nebria .

Remarks.

Members of this group are easily identified as members of the Reductonebria Complex using the Ledoux and Roux’s (2005) key to subgenera. Features that distinguish them from members of subgenus Reductonebria Insulanebria have been discussed above for that taxon. We have not yet identified any external morphological features that consistently distinguish all members of all species of Reductonebria from all Erwinebria members, but there are several distinguishing internal features evident in both sexes. The mid-shaft is parallel-sided or slightly to moderately narrowed basally and the apical orifice is markedly to extremely deflected right in Erwinebria males. In Reductonebria males, the mid-shaft is markedly narrowed apically and the apical orifice is only moderately deflected right. As in most other Nebria examined, the gonopods VIII in Erwinebria females are fused dorsomedially with the bases of gonocoxae. In Reductonebria females, these gonopods are distinctly separate from, although in the same position in relation to, the gonocoxae. The spermathecal chamber is broadly cordate in dorsal aspect in Erwinebria females, but somewhat broadly ovoid in Reductonebria females. Although most members of both of the subgenera have sclerotized plates in the dorsal or dorsoapical wall of the spermathecal chamber of bursa copulatrix, they are of a different form in the two groups. In Erwinebria females (except in N. lyelli and N. quileute , which have no dorsal sclerites), the dorsal sclerite is variously formed as a small to large domed, horseshoe- or saddle-shaped plate associated with the point insertion of the spermathecal duct on the chamber. In Reductonebria females, the sclerotized area is predominately an apicodorsal cap on the spermathecal chamber. This cap sclerite may be relatively small, round, and smooth, as in N. ochotica , N. mannerheimii and N. darlingtoni females, or larger, crenulated rather than smooth, and/or expanded laterally or basally to or beyond the insertion point of the spermathecal duct.

Known distribution and diversity.

The geographical range of this clade covers much of western North America, from the outer Aleutian Islands in the northwest, south to eastcentral California, northern Arizona, and New Mexico and east to the eastern edge of the Rocky Mountain system from Yukon Territory in Canada south to northcentral New Mexico.

Twenty-one species in this clade have been described.