Lionepha disjuncta, (LINDROTH, 1963)

LIONEPHA DISJUNCTA ( LINDROTH, 1963) View in CoL

( FIGS 2D, 16G, H, 12G, H, 23)

Bembidion disjunctum Lindroth, 1963: 264 View in CoL . Holotype ♂ in MCZ (type # 32533), examined. Type locality: Sonora Pass , Tuolumne County, California.

Diagnosis: A flat, parallel-sided species with more complete striae than other Lionepha ( Fig. 2D), and with relatively strong, slightly transverse elytral microsculpture ( Fig. 16G, H). Aedeagus ( Fig. 12G, H) similar to other members of the erasa group, with a more or less ovoid CH 1 sclerite.

In appearance L. disjuncta resembles a small member of Bembidion subgenus Plataphus , or a Bembidion nebraskense LeConte, 1863 . From sympatric Bembidion (Plataphus) specimens it can be distinguished externally by the completely bordered metasternal process (bordered at the sides only in Plataphus ). The elytral striae are less distinct in L. disjuncta . In Plataphus , multiple striae will be easily evident near the elytral apex. The aedeagus is different from Plataphus , without the evident flagellum present in members of that subgenus. From Bembidion nebraskense it can be immediately distinguished by the presence of elytral microsculpture: B. nebraskense lacks elytral microsculpture and is thus glossy.

Additional characteristics: Body length 3.62–4.32 mm. Antenna piceous. Femora rufopiceous or piceous, tibiae rufopiceous or rufous. Hind wings full-sized. Chromosomes of male 24 + X ( Table 5).

Geographic variation: This species shows notable variation in 28S, with numerous insertion and deletion events evident (Supporting Information, Fig. S1). Of the ten specimens sequenced, seven have unique indels, and the remaining three share an eighth pattern of insertions and deletions. In addition, the specimen from the Wallowas that was sequenced has a unique amino acid, threonine, within COI, although other L. disjuncta have alanine at that position (base 356 in the sequence of specimen DNA3848, GenBank accession number MN402196 View Materials ).

Distribution: A widespread species, from the northern Sierra Nevada and Trinity Alps of northern California, north to southern British Columbia and east to Montana ( Fig. 23). Found between 650 and 2930 m in elevation. Most records are from late summer and early fall, with specimens having been collected in June through September, as well as one record from April.

Habitat: This species is usually encountered as a specimen or two amongst more common Bembidion on gravel and cobble shores of cold, clear creeks and rivers. There are two localities where numerous specimens have been found: Summit Creek west of Creston, British Columbia, and in the Lostine River valley in the Wallowas of Oregon. At the latter locality, 36 specimens were found in the drying bed of a small creek in a forest ( Fig. 4D), along with numerous Lionepha kavanaughi and L. probata , as well as Bembidion kuprianovii .