Lamproscatella cephalotes Cresson 1935

Lamproscatella (Haloscatella) cephalotes Cresson

Lamproscatella cephalotes Cresson, 1935:360.—Wirth and Stone, 1956:475 [key, distribution in California].—Wirth, 1965:756 [catalog].

DIAGNOSIS.—This species and L. arichaeta are closely related as evidenced by their overall similarity. However, specimens of L. cephalotes may be distinguished from those of L. arichaeta and other congeners by the following combination of characters: Setal development more pronounced, appearing exaggerated; length of specimens averaging larger; mesonotum grayer in color. The structures of the male terminalia are larger, especially the surstyli which are fingerlike and densely setose along median surface (Figures 10–12).

DESCRIPTION.—Moderately small shore flies, length 2.05 to 2.90 mm (averaging 2.64 mm); coloration generally grey, often tinged with light blue or faint green, some brown colored areas on dorsum.

Head (Figures 7–9): Head width-to-height ratio averaging 1:0.7; mesofrons subtriangular, subshiny to shiny with metallic bluish green luster, contrasting with gray to charcoal gray parafrons, anterior margin with 1–3 setae. Ocellar triangle raised in relief from mesofrons, pollinose, brownish gray. Anterior fronto-orbital seta well developed, length over one-half that of larger fronto-orbital bristles; third fronto-orbital seta much reduced, situated mesad of alignment of other setae. Postocular bristle inserted posterolaterad of divergent vertical bristle, length approximately double that of other postocular setae. Antenna dark, brownish black, pollinose, with some gray pollinose areas; arista short, subequal to length of second and third segments. Face distinctly protruding, arched, pollinose, generally gray but usually with faint brown coloration toward interfoveal carina; 2 larger facial setae inserted just below interfoveal carina, oriented obliquely, lateroventrad; second pair of larger, lateral setae oriented almost directly laterad; third pair of setae largest, inserted near posteroventral angle of face, slightly dorsally-curved; other facial setae subequal to each other, small; oral setae only slightly larger than facial setae. Eye-to-cheek ratio averaging 1:0.60; gena concolorous with face or lighter.

Thorax: Dorsum pollinose, generally gray, especially scutellum but with light brown areas of variable size. Setae appearing exaggerated, very well developed. Legs gray but with considerable darker appearing areas; basitarsi sometimes appearing amber colored, terminal tarsomeres charcoal gray. Wing hyaline to brownish tinged; costal margin distinctly setose; costal vein ratio averaging 1:0.15; M1+2 vein ratio averaging 1:0.61, posterior crossvein often wrinkled, posterior half slightly angulate laterally.

Abdomen: Generally concolorous with thorax, with varying degrees of faint brown coloration, especially toward margins. Structures of male terminalia as in diagnosis and Figures 10–12.

TYPE MATERIAL.—Holotype male is labeled: “Salt Lake 26•6 Ut/H S Barber Collector//Type No. 21844 U.S.N.M. [red]/Holo-TYPE 1 Scatella CEPHALOTES E. T. Cresson Jr. [red]/Type No. 51102 U.S.N.M. [red].” Allotype female has same label data as holotype. The holotype and allotype are in the National Museum of Natural History, Smithsonian Institution, Washington, D. C., type number 51102.

SPECIMENS EXAMINED.—UNITED STATES: CALIFORNIA: Mono Co., Mono Lake, 2.4 km NE Mono Inn, 29 Feb 1964, J. D. Birchim (2 CAS), west shore Mono Lake, 22 Jun 1974, W. N. Mathis (17 , 28 ; USNM). IDAHO: Elmore Co., 22 May 1938, H. S. Telford (1 ; UMN). NEVADA: Washoe Co., Pyramid Lake, 24 Jun 1964, J. A. Miller (5 , 3 ; UCD, USNM). OREGON: Lake Co., Abert Lake, 6.4 km N Valley Lake, 2 Jul 1964, J. D. Lattin (1 ; USNM). UTAH: Cache Co., Logan, 27 Jun 1960, G. F. Knowlton (1; UCD); Salt Lake Co., Salt Lake, 26 Jun, H. S. Barber (1, 1; ANSP).

GEOGRAPHIC DISTRIBUTION (Figure 13).—This species occurs in the Great Basin of the western United States from the area between 37° and 43° north latitude and west of 110° west longitude.