Brachygluta (Brachygluta) klamath Bückle, 2015

Chandler, Donald S., Sabella, Giorgio & Bückle, Christoph, 2015, A revision of the Nearctic species of Brachygluta Thomson, 1859 (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 3928 (1), pp. 1-91 : 73-75

27. Brachygluta (Brachygluta) klamath Bückle , sp. n.

( Figs 32 , 42 B)

Material examined, 33 specimens. HOLOTYPE male: USA: Oregon: Klamath Co.: //Oregon: Kla. Co., Lower Klamath L., II-4/22 –1963/ JSchuh, under rock pile w/ants/ [red label] HOLOTYPE Brachygluta klamath Bückle // [with ant on point] ( AMNH). PARATYPES, 32: USA: Oregon: Harney Co.: Harney Lake Hot Springs, 28.V.1957, H.S. Dybas leg., along margin ( UCDC, 1M). Klamath Co.: eutopothypical, ( DSCC, 6M, 18F); Lower Klamath Lk., IV-16-1962, J. Schuh, rock outcrop ( DSCC, 1M, 2F). Lake Co.: SE shore L.(ake) Abert, fresh pool, 17-VII-50, H.B. Leech Collector ( UCDC, 1M). Abert Lake, VI-7-1958, Vertrees & Schuh ( UCDC, 2M). California: Siskiyou Co.: Indian Tom Lake, 17 mi SW of Klamath Falls (Oregon), June 19, 1978, L. & N. Herman #1483 ( AMNH, 1M).

Description. BODY: Length 2.16–2.28 mm; red-brown with orange-brown elytra; head and pronotum with setae short, curved and suberect, over rest of body longer and decumbent. Head: surface smooth, shining, punctures indistinct. Antennomeres III-VI longer than wide, VIII–IX as long as wide, X longer than wide, VIII about twothirds width of IX ( Figs 32 D–E). Setose area of median vertexal fovea as large as those of lateral foveae. Pronotum: surface smooth, shining, punctures indistinct. Setose area of median antebasal fovea about two-thirds width of lateral antebasal foveae. Elytra: with faint microreticulation, punctures indistinct, discal stria extending to about four-fifths of elytral length. Abdomen: disc smooth, shining, punctures indistinct. Basal striae of tergite 1 about one-fourth paratergite length, straight, separated at base by one-half tergite width, setose brush between bases of striae composed of thin sparse setae in both sexes.

MALE: Antennae and trochanters unmodified, simple. Metaventrite with elongate-arcuate area of dense setae projecting anteriorly from between metacoxae, setose area lightly depressed; tergite 1 broadly and shallowly emarginate, middle third slightly deflexed, setae along apex relatively sparse, not denser at emargination ( Fig. 32 A), in lateral view apex of tergite 1 only slightly protruding over base of tergite 2; tergite 2 with low carina at base, carina appearing slightly sinuate, carina beneath apex of tergite 1 and not visible in dorsal view, middle portion of carina lacking, disc with flattened longitudinal area at middle extending from carina to tergite apex, sometimes more distinct as slight impression ( Figs 32 B–C); in lateral view with apex of 1 slightly elevated above base of 2, all confluently curved. Abdominal ventrites broadly rounded. Metatibiae thin, narrow at base, gradually widened to near apex, mesal margin of apical fourth with brush present ( Fig. 32 F). Aedeagus 0.40 mm long; with dorsal plate triangular, margins in apical half concave, apex bluntly pointed; parameres with distinct preapical constriction, three thick setae on lateral margin at basal angle of constriction, flattened preapical hyaline setae near mesal margin widening to middle, apex aciculate; internal sac with two large spines, one strongly curved, one straight except at base ( Fig. 32 G).

FEMALE: Metaventrite impressed between metacoxae, but setae not dense, similar to rest of metaventrite; lacking abdominal modifications. Otherwise similar to male.

Collecting data. Found around the margins of lakes and hot springs; one large series was taken with Pogonomyrmex ants from beneath rocks. Taken from February through July.

Distribution ( Fig. 42 B). South-central Oregon and adjacent California, primarily within the Klamath River drainage.

Comments. The lack of a distinct transverse basal impression places this species near B. chisos . The medianly flattened tergite 2, together with the basal carina that is lacking medially is distinct and slightly lobed laterally, serves to distinguish this species from all others.

Etymology. Named for the group of American Indians that live in this area of the United States.

Figures

FIGURE 32. Brachygluta klamath Bückle. A: Abdomen, dorsal view (Oregon, Lake Co., paratype). B: Abdomen, caudal view (Oregon, Lake Co., paratype). C: Abdomen, caudal view (Oregon, Klamath Co., paratype). D: Right antenna (Oregon, Lake Co., paratype). E: Right antenna (Oregon, Klamath Co., paratype). F: Left metatibia, anterior view (Oregon, Klamath Co., paratype). G: Aedeagus (Oregon, Klamath Co., paratype).

FIGURE 42. Distribution map of Brachygluta seri species-group and Brachygluta mormon species-group. A: Brachygluta chisos Sabella. B: Brachygluta klamath Bückle. C: Brachygluta cochimi Bückle. D: Brachygluta seri Chandler.