Nebria Neaptenonebria 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 Neaptenonebria Kavanaugh, subgen. nov.

Nebria ovipennis = " Nebria ovipennis group" (in part) sensu Lindroth 1961.

Catonebria Shilenkov, 1975 (in part); = " Nebria kincaidi group" sensu Ledoux and Roux 2005.

Type species.

Nebria ovipennis LeConte, 1878:477, by present designation.

Diagnosis.

Body size small to medium, SBL = 9.4 to 12.8 mm. Head width medium or slightly to markedly broadened, not constricted behind eyes; vertex with a pair of paramedial pale spots on vertex and one pair of supraorbital setae. Eyes moderate in size or slightly reduced, moderately convex. Antennae slightly to moderately elongate; antennal scape with one 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 (except only two present in Nebria carri Kavanaugh, 1979 specimens). Pronotum markedly to extremely cordate in dorsal aspect, with lateral margination faintly impressed and slightly narrow at middle; one midlateral seta and one basolateral seta present on each side (except basolateral setae absent from N. carri , Nebria balli Kavanaugh, 1979 and Nebria kincaidi Schwarz, 1900 specimens). Elytral intervals smooth, moderately convex, without macrosculpture; elytral interval 3 with two to seven setiferous pores, interval 5 with zero or one setiferous pore, and interval 7 with zero to two or more setiferous pores; umbilicate series comprised of from ten to 17 setae; intervals bearing setae faintly to moderately catenate. Hindwings reduced to short, slender strap-like vestiges. Metasternum very markedly to extremely short. Metepisterna smooth, impunctate. Protarsomeres 1-3 expanded in males (except all five tarsomeres expanded in males from some populations of N. ovipennis LeConte, 1878); mesotarsomeres 2-4 longer than their apical width (except expanded in specimens from some populations of N. ovipennis ); tarsi dorsally glabrous. Abdominal sternites IV-VI with from one (seen only in some specimens of N. balli ) to five or more pairs of posterior paramedial setae and with from zero to five pairs of posterior paralateral setae; sternite VII with one pair of paramedial apical setae in males, two pairs in females. Median lobe of male aedeagus sclerotized dorsally at least to midlength on shaft, symmetrical to slightly 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 in lateral aspect, slightly to moderately compressed in cross-section, with right lateral face with a distinctly and deeply invaginated pouch; apical orifice extremely deflected right. Right paramere narrow and slightly shortened. Female hemisternites VIII with basal apodeme very deeply emarginated. Female valvifer without vestiture; gonopods VIII fused to dorsomedial bases of gonocoxae; gonocoxae with ventral diagonal row of setiform setae and mediodorsal row of setae present, mediodorsal row oriented obliquely relative to longitudinal axis of gonocoxa. Bursa copulatrix without dorsal sclerites in vestibular chamber and without a posterodorsal extension from its longitudinal axis in lateral aspect; spermathecal chamber broadly cordate in dorsal aspect, without dorsal sclerites (in most species) or with a simple flat plate on dorsal surface of an accessory lobe (in N. kincaidi and N. balli ); spermathecal duct medium to slightly short in length and of uniform diameter throughout or nearly so, inserted basodorsally on spermathecal chamber or on a dorsal accessory lobe of that chamber; spermathecal duct slightly short to medium length; spermathecal reservoir of medium length.

Etymology.

The subgeneric epithet is a noun of feminine gender and combination of the Greek word, neos, meaning new, in reference to the Nearctic (New World) distribution of the group, the Greek word, aptenos, meaning unable to fly, and the genus name, Nebria , in reference to the observation that all known members of this clade have extremely reduced hindwings incapable of supporting flight.

Remarks.

Members of this group are easily identified as members of the Catonebria Complex using the Ledoux and Roux’s (2005) key to subgenera. Features that distinguish them from members of subgenus Neaptenonebria Nivalonebria have been discussed above for that taxon. We have not yet identified any external morphological feature that consistently and satisfactorily distinguishes all members of all species of Neaptenonebria from all Catonebria members. The hindwings are more highly reduced (to short, slender strap-like vestiges) in all Neaptenonebria members than in any Catonebria member. The most highly reduced hindwings seen among Catonebria species are in Nebria pektusanica Horvatovich, 1973) from Changbei Shan (named Mt. Pektusan in North Korea), and they are short and lobate with some recognizable venation present. Features associated with wing loss in carabids, especially Nebria , are poor indicators of relationship, but they can still serve to aid identification. Internally, Neaptenonebria males have the right paramere of the aedeagus narrowed and slightly shorter than is typical for Nebria males, including those of Catonebria , but the difference is not dramatic. All males of Neaptenonebria species have the right lateral face of the mid-shaft region of the aedeagal median lobe with a distinct longitudinal groove, the basal end of which is invaginated as a moderately (as in N. ovipennis males) to deeply invaginated and basally-directed pouch (as in N. carri males). Presence of an invaginated pouch is distinctive for this clade; but males of Palaptenonebria species and Catonebria members of the Nebria gebleri group, as well as of N. metallica Fischer von Waldheim, 1822 and Nebria labontei Kavanaugh, 1984, also have a shallow, more or less distinct longitudinal groove in this location. Neaptenonebria females have the mediodorsal row of setae on the gonocoxae oriented obliquely in relation to the longitudinal axis of the gonocoxa, whereas this setal row is parallel to the longitudinal axis in females of other subgenera of the Catonebria Series.

A few additional features distinguish members of this clade from most members of the Palaptenonebria clade. Most adults of Neaptenonebria species are medium-sized with SBL> 10 mm, whereas all Palaptenonebria adults are smaller, with SBL ≤ 9.5 mm; but smallest the members of the former clade (SBL = 9.4 mm) overlap in size with the largest members of the latter (SBL = 9.5 mm). In Neaptenonebria species, the pronotal shape is more extremely cordate with the lateral pronotal margination more faintly impressed and less narrowed at the middle than in Palaptenonebria species. The elytra are more convex in Neaptenonebria species than in Palaptenonebria species, and the elytral umbilicate series is comprised of 11-17 setae in Neaptenonebria species but only 8-12 setae in Palaptenonebria species. The length of the metasternum is greatly reduced in both of these clades but more extremely so among Neaptenonebria adults. Most members of all species of the Neaptenonebria clade except N. ovipennis have paralateral setae on sternites IV-VI, and, when present, these setae are inserted much nearer to the posterior than the anterior margin of the sternite. All specimens examined of several species of the Palaptenonebria clade lack paralateral setae and, in the other species and those individuals in which these setae are seen, they are inserted in a more anterior position on the ventrites. In all Neaptenonebria species, all males examined have a single pair of apical paramedial setae on sternite VII and females have two pairs of these setae, whereas in all Palaptenonebria species at least some if not most or all males have two or more pairs of setae and at least some females have three or more pairs of setae. Finally, the basal apodemes of the female hemisternites VIII are more deeply emarginate in all Neaptenonebria females than in any Palaptenonebria females.

Known distribution and diversity.

The geographical range of this clade is restricted to western North America. It includes six species that together occupy a disjunct geographical distribution, with three species endemic to the Sierra Nevada of California and westernmost Nevada, one endemic to the mountains of Central Idaho and the Bitterroot Mountains of westernmost Montana, one to the Cascade Range of southern Washington and northern Oregon, and one to the western slope of Coast Ranges of southeastern Alaska and British Columbia south to Vancouver Island and the Olympic Peninsula of Washington.