Setacera needhami Johannsen 1935

Setacera needhami Johannsen

Setacera needhami Johannsen, 1935:53.—Cresson, 1935:347 [description of adult].—Sturtevant and Wheeler, 1954:202, 203 [key and locality data].—Wirth and Stone, 1956:472 [key].—Wirth, 1965:755 [nearctic catalog].—Cole, 1969:402 [locality data].

DESCRIPTION.—Moderately small to moderately large shore flies, length 2.98 to 4.54 mm; dorsum generally dark, brown, olivaceous green to grayish green, becoming more subdued, lighter, grayer ventrally.

Head (Figure 99): Head width-to-height ratio averaging 1 : 0.69; mesofrons and fronto-orbits deeply dark blue to greenish blue, dorsum of interfoveal carina mostly greenish; frons width-to-length ratio averaging 1 : 0.59; arista with longest branching rays nearly twice greatest aristal width; dorsal surface of face with antennal fovea inclined at distinctly lower level than dorsum of interfoveal carina; dorsal surface of face shorter than anterior surface in profile; facial angle moderately angulate, about 110°; angle formed by anterior surface and oral margin obtuse, anterior surface receding. Eye height-to-width ratio averaging 1 : 1.02; eye-to-cheek ratio averaging 1 : 0.37.

Thorax: Supraspiracular convexity evenly convex; fore- and midcoxae of male normal; midfemur of male (Figures 105, 106) with 4–5 long, well-developed setae ventrally toward base; midtibia of male (Figures 105, 107) with large, dense patch of long setae anteroventrally to ventrally; hind tibia of male with small patch of long setae anteroventrally; costal vein ratio averaging 1 : 0.28; M1+2 vein ratio averaging 1 : 0.84.

Abdomen: Male 5th tergal ratio averaging 1 : 0.62; 5th tergum of male lacking anteroventral process. Male terminalia (Figures 100, 101): surstyli broadly based in posterior view, lateral margins rounded to just before apex, thereafter more or less parallel sided, short, apex wide and shallowly emarginate, lateral projections very shallow; gonite with slender dorsal and ventral prongs, both curved medially, with 2 long posteriorly directed setae inserted at about midheight in lateral view; aedeagus folded back on itself; hypandrium very poorly sclerotized medially, laterally and posteriorly well sclerotized, with 2 long, well-developed anteromedial prongs, tapered to acutely pointed apex. Female terminalia (Figures 102–104): 7th tergum complete; 8th tergites more or less subquadrate in lateral view, dorsum shallowly sinuate, posterior margin concave, posteroventral corner more projected, nearly as high as wide; 8th sternites elongate, 5–6 times longer than width; cercus wider than high in lateral view, posterior margin shallowly rounded; female ventral receptacle (Figure 104) with dorsum of operculum bearing shallow, median bump, lateral margins rounded, otherwise as in species group description.

TYPE MATERIAL.—The male lectotype, herein designated, is labeled: “Laguna Canyon Orange Co. Cal[ifornia]. [handwritten]/Shore of Pond J. G. Needham Sept. 1922 [handwritten]/TYPE No. 6574 Setacera NEEDHAMI E T Cresson, Jr. [red]/LECTOTYPE Setacera needhami Johannsen by W. N. Mathis [handwritten, red].” The lectotype is in the Academy of Natural Sciences of Philadelphia, Pennsylvania. The specimen is double mounted (glued to a paper point) and is in good condition, although the right front leg and the apical tarsomeres of the middle left leg are missing.

OTHER SPECIMENS EXAMINED.—UNITED STATES. Arizona: Yuma Co., Horsetank, 2 Dec 1962, E. I. Schlinger (1; UCR California: Alameda Co., Berkeley, 4 Oct 1947, W. W. Wirth (2, 2; USNM); Jewell Lake, 4 Oct 1947, W. W. Wirth (2, 5; USNM Colusa Co., Maxwell, 12 Aug 1954, A. A. Grigarick (1, 1; USNM Contra Costa Co., Jewell Lake, 4 Oct 1947, W. W. Wirth (3, 1; USNM Humboldt Co., Trinidad, 18 Sep 1934, A. L. Melander (1; USNM Inyo Co., Independence, 13 mi NE, 10 Mar 1964, J. D. Birchim (1; CAS Kern Co., Poso Creek, 18 Jun 1947, B. Brookman (1; USNM Riverside Co., Temecula, 25 May 1965, T. W. Fisher (1; UCR Orange Co., Laguna Beach, J. G. Needham (2 larvae, 1 puparium; CU); Laguna Canyon, J. G. Needham (3; ANSP Sacramento Co., Sacramento, 8 Jun–24 Sep, 1920–1933, H. H. Keifer, C. M. Packard (6, 9; USNM); Citrus Heights, 11–15 Jun 1967, Keuter (2; CAS San Bernardino Co., Wrightwood, 30 Apr 1950 (5, 4; USNM San Diego Co., San Diego, 12–13 May 1916, H. G. Dyar (2; ANSP, USNM Shasta Co., Redding, 7 Nov 1970, T. R. Haig (1; USNM Tehama Co., Corning, ½ mi S, 23 Sep 1973, W. N. Mathis (1, 1; USNM Yolo Co., Davis, 30 Jan–21 Oct, 1932–1966, J. S. Buckett, A. A. Grigarick, M. E. Irwin, W. H. Lange, H. R. Moffitt, E. I. Schlinger (4, 7; USNM Nevada: Washoe Co., Pyramid Lake, 24 Jun 1927, E. P. Van Duzee (1; CAS Oregon: Benton Co., Corvallis, 29 Mar–20 Jun, 1960–1972, J. Capizzi, W. N. Mathis (2; USNM); Corvallis, 12 mi S, 12 Sept 1972, W. N. Mathis (1, 2; USNM); Oak Creek Lab, 9 Sep 1972, W. N. Mathis (1 WNM); Willamette River, 12 Oct 1971, W. N. Mathis (2, 2; USNM Linn Co., Peoria, 2 mi S, 24 Oct 1971, W. N. Mathis (1, 1; KSU, USNM Polk Co., Corvallis, 14 mi N, 24 May 1972, W. N. Mathis (2; USNM Umatilla Co., Cold Springs, 11 Apr 1954, J. J. Davis, M. T. James (1; USNM Utah: Davis Co., Farmington, 13 Feb 1934, W. L. Thomas (1; ANSP Weber Co., Hooper, 20 Oct 1933, T. A. Rowe (1; ANSP Washington: Franklin Co., Kahlotus Lake, 11 May 1951, J. J. Davis (1, 1 puparium; USNM Grant Co., Soda Lake near O'Sullivan Dam, Columbia Wildlife Refuge, 19 Mar 1977, R. S. Zack (24, 11; USNM, WSU Pacific Co., Ocean Park, 18 Aug 1950, M. T. James (1; WSU Whitman Co., Almota, 23 Mar 1977, R. S. Zack (1; USNM

ZOOGEOGRAPHIC DISTRIBUTION (Figure 108—Western North America between 111° and 125° west longitude and 32° and 48° north latitude.

NATURAL HISTORY.—I have collected adults of this species at numerous localities in association with lentic aquatic systems. Presumably the immature stages also occur in these habitats.