Bembidion oromaia, Sproul & Maddison, 2018

Sproul, John S. & Maddison, David R., 2018, Cryptic species in the mountaintops: species delimitation and taxonomy of the Bembidion breve species group (Coleoptera: Carabidae) aided by genomic architecture of a century-old type specimen, Zoological Journal of the Linnean Society 183, pp. 556-583 : 580-581

BEMBIDION OROMAIA SP. NOV.

( FIGS 3, 9I, 10I, 11I, 13C, 17B)

Holotype male (in OSAC) herein designated, labelled ‘ USA: California: Tulare Co., snow field above Emerald Lake, 2851 m, 36.5959°N 118.6756°W, 21.vi.2014. JSS 2014.064-12 [‘-12’ handwritten]. J.S. Sproul & Family’ [white paper], ‘David R. Maddison DNA4250 DNA Voucher’ [pale green paper], ‘ HOLOTYPE Bembidion oromaia Sproul + Maddison 2017 ’ [partly handwritten, red paper], ‘Sequoia and Kings Canyon National Parks SEKI 23092’ [green paper], ‘ Oregon State Arthropod Collection OSAC_0002000002 [matrix code]’ [printed on both sides of white paper]. Genitalia mounted in Euparal on small card labelled ‘DNA4250’ beneath the specimen; extracted DNA stored separately. GenBank accession numbers for DNA sequences of the holotype are KY950760 (28S), KY950889 ( CAD), KY951019 (COI), KY951149 (MSP), KY951276 ( Topo ).

Type locality: USA: California: Tulare Co., snowfield above Emerald Lake , 2851 m, 36.5959°N 118.6756°W .

Paratypes: Thirty-two specimens from the following localities, with specimens deposited in CAS, OSAC, and USNM: USA: California: Tulare Co., Upper East Fk. Kaweah River , 2812 m, 36.4189°N 118.5927°W (12) ; USA: California: Tulare Co., snow field above Emerald Lake , 2851 m, 36.5959°N 118.6756°W (6) ; USA: California: Tulare Co., snowfield below White Chief Lake , 2912 m, 36.417°N 118.5941°W (3) ; USA: California: Tulare Co., Lower Franklin Lake , 36.4203°N 118.5614°W (1) ; USA: California: Tuolumne Co., Blue Canyon Creek , 2750 m, 38.3151°N 119.6613°W (2) ; USA: California: Tuolumne Co., stream draining N. face Leavitt Peak, 2930 m, 38.3098°N 119.6619°W (2) ; USA: California: Tuolumne Co., Deadman Creek , 2700 m, 38.3188°N 119.6634°W (1) ; USA: California: Tuolumne Co., Hwy. 108, stream SE of Chipmunk Flat, 2440 m (1); USA: California: Tuolumne Co., Deadman Creek at junction with Blue Canyon Creek , 2665 m, 38.3174°N 119.6652°W (1) ; USA: California: Mono Co., snow field above Ellery Lake , 37.9345°N 119.2318°W (2) ; USA: California: Mono Co., H. M. Hall Natural Area, Lee Vining Creek , 3020 m, 37.9591°N 119.2838°W (1).

Derivation of specific epithet: Derived from Greek roots, with ‘ oro ’ meaning ‘mountain’, and ‘ maia ’ meaning ‘good mother’, or ‘caregiver’. Thus, the name connotes ‘good mother of the mountain’ or ‘caregiver of the mountains’. The name recognizes the contribution of Elizabeth C. Sproul to the present work. Mother of George and Pearl mentioned above, Elizabeth has spent hundreds of hours traveling to breve group localities, guiding young legs up steep trails, waiting at trailheads, recording locality data, and collecting and processing specimens in support of JSS’s dissertation research, and to enable positive associations for George and Pearl. Her steady support has added tremendous physical and emotional energy to the sampling efforts and overall scope of this work. The specific epithet also references the beetles. Distributed at higher elevation than any other members of the group, their elegant appearance inspires imagery of a maternal caregiver high in mountains.

Diagnosis: This large-bodied black species with long, slender appendages is the most distinctive member of the group ( Fig. 3). Forebody and hindbody black, commonly with greenish or bluish metallic lustre. Pronotum narrow relative to elytral width and sinuate laterally; hind angles near 90° ( Fig. 11I). Elytra widest behind middle with microsculpture meshes strongly etched in females and moderately etched in males ( Fig. 13C). Legs and antennae black, long and slender; first protarsomeres in males quite small (not illustrated as Fig. 3 is a female). Male genitalia distinctive with outer shape having the appearance of being bent basally; flagellum long and sinuate; sclerite ‘St’ elongate, bilobed and heavily sclerotized ( Figs 9I, 10I).

Comparison with similar species: Most easily confused with B. laxatum from which it is distinguished by having a pronotum which is narrower relative to the elytra, and more sinuate laterally, longer and more slender legs and antennae, smaller first protarsomeres in males, opaque black coloration, and by various male genitalic characters.

Geographic distribution: Throughout the Sierra Nevada, north to Mount Lassen and the Trinity Alps in California ( Fig. 17A).

Habitat: Open alpine slopes under fairly large rocks on soil, commonly below patches of melting snow. Also present along small alpine creeks.

Geographic variation: The single specimen we sampled from the Trinity Alps in California has two distinctive bases in 28S (a gene for which all other specimens have identical sequences), but is not notably distinctive in other genes.