Calyxochaetus vegetus (Wheeler)

Runyon, Justin B., 2024, Revision of the genus Calyxochaetus Bigot (Diptera: Dolichopodidae: Sympycninae), Zootaxa 5539 (1), pp. 1-74 : 44-46

Calyxochaetus vegetus (Wheeler)

( Figs 80, 86, 87, 91 , 94 )

Nothosympycnus vegetus Wheeler, 1899: 53 .

Calyxochaetus vegetus : Parent (1930: 107).

Type material examined. LECTOTYPE (designated here to fix identity of the species) ♂, labeled: “Monterey/ Co., Cala./ July 8 ’96.”; “ W. M. Wheeler / Collection.”; “Type”; “ LECTOTYPE / Calyxochaetus / vegetus (Wheeler) / des. J.B. Runyon [blue label]” (AMNH) . PARALECTOTYPES: Same data as lectotype (1♂, 2♀, AMNH) ; same data except, 17.vii.1896 (3♂, 2♀, AMNH) .

Other material examined. CANADA: British Columbia: 32 km N Nakusp, 3.ix.1991, CD1376, A. Borkent (1♂, CNC). USA: California: Alpine County: Indian Creek Lake, 15.vi.1979, G.E. Bohart (1♂, LACM); Humboldt County: Arcata Dunes, 19.vii.1981, RLH (1♀, MTEC); same data except, 21.vii.1981 (1♂, MTEC); Los Angeles County:Valyermo, 13.v.1944, ALM (2♂, USNM); Mendocino County: Hopland Field Station, Kelsey Meadow, 2400 ft, 14.v.1977, sweeping mossy seepage, J. Powell (1♂, EMEC); Mono County: Mono Lake, 21.vii.1911, J.M. Aldrich (2♂, USNM); Monterey County: 8.vii.1896 (1♂, USNM); Paraiso Hot Springs, 400 m, 31.viii.1975, P.H. Arnaud, Jr (4♂, CAS); San Bernardino County: 29 Palms, 9.v.1946, ALM (1♂, USNM); Victorville, 24.v.1955, W.R.M. Mason (1♂, CNC); San Francisco County: San Francisco, Golden Gate Park, Strybing Arboretum, 13.vi.1977, P.H.Arnaud, Jr (1♂, CAS); San Mateo County: Redwood City, 7.iv.1906, J.M. Aldrich (1♂, USNM); Stanford University, Jasper Ridge Biological Preserve, south end of Searsville Lake, 100 m, 14–16.x.1990, P.H. Arnaud, Jr (1♂, CAS); Moss Beach, 29.iv.1949, C.H. Spitzer (1♂, EMEC); Santa Clara County: Stanford University, 11.iv.1906, J.M. Aldrich (1♂, USNM); same data except, 30.iv.1910 (1♂, USNM); Shasta County, 2 mi. W Shingletown, 2750 ft, damp open meadow, Malaise, 25–30.vii.1985, R. Miller (1♂, FSCA). Idaho: Blaine County: Huff Creek (hot spring), N43°21.85’ W113°47.36’, 20.v.2015, JBR (2♂, MTEC); same data except, 16.v.2016 (1♂, 1♀, MTEC); Custer County: Stanley, Mountain Village Hot Spring, 44.2210°N 114.9311°W, 6.ix.2022, JBR (4♂, 4♀, MTEC); Idaho County: Snake River, Divide Creek, 10.v.1925, ALM (2♂, USNM); Latah County: Moscow, J.M. Aldrich (1♂, USNM); Viola, 21.viii.1912, J.M. Aldrich (1♂, USNM); Nez Perce County: Juliaetta, J.M. Aldrich (1♂, USNM); Juliaetta Falls, 5.2 mi. S Juliaetta, 5.ix.1980, R.S. Zack (1♂, WSU). Nevada: Elko County, Wells, 6.viii.1965, FCH (2♂, FSCA). New Mexico: Colfax County: Springer, C.N. Ainslie (1♂, USNM). Oregon: Benton County, Corvallis, 1902 (1♂, USNM); Clatsop County: Cannon Beach, 3.viii.1965, plants around seepage area, K. Goeden (2♂, FSCA; 1♂, CSCA); Gilliam County: 12.8 mi. W Blalock, 27.ix.2000, RLH & JBR (2♂, MTEC); Harney County: 6 mi NW Fields, 29.ix.1964, sweeping plants at margin of warm spring (1♂, FSCA); Jackson County: Squaw Lake, 22.v.1964, J. Schuh (1♂, WSU); Lake County: Adel, 20.vi.1963, FCH & L.S. Miller (1♂, FSCA). Utah: Beaver County: Beaver, 19.v.1940, Knowlton & FCH (1♂, MTEC); Davis County: Farmington, 2.ix.1950, on celery, G.F. Knowlton (1♂, USNM); Iron County: Parowan, 27.vi.1956, FCH (1♂, FSCA); Kane County: Johnson, 17.v.1940, G.F. Knowlton & FCH (2♂, 1♀, LACM; 1♂, USNM); Kanab, 17.v.1940, G.F. Knowlton & FCH (2♂, MTEC); 50 Mile Mountain, Pinto Mare Canyon, 8.viii.2000, sweeping wet seep, 37°18’03N 111°09’14W, H.A. Barber, E.C. Green, W.N. Mendel, M. Moody & C.R. Nelson (1♂, 1♀, BYU); same data except, Lake Pasture near Griffin Cabin, 37°17′48″N 111°08′29″W, 7–8.viii.2000 (1♂, 1♀, BYU); same data except, Sheep Creek, 5914 ft, 37°29′44″N 112°03′56″W, 12.v.2000, K.T. Huntzinger, W.N. Mendel & C.R. Nelson (1♂, BYU); Utah County: Mount Timpanogos, 17.viii.1941, FCH & G.F. Knowlton (1♂, CNC); Provo, 21–28.viii.1985, Malaise (1♂, LACM); Washington County: Santa Clara, 19.vii.1941, G.F. Knowlton & FCH (2♂, CNC); Beaver Dam Slope, Lytle Ranch Preserve, 10–12.viii.1983, Malaise, W.J. Hanson (1♂, LACM); Weber County: Ogden, 21.v.1940, G.F. Knowlton & FCH (1♂, MTEC). Washington: Asotin County: Asotin Creek, 11.v.1924, ALM (1♂, USNM); Silcott, 14.vi.1980, G.C. Steyskal (1♂, USNM); 6 mi. W Asotin, along Asotin Creek, 22.vii.1985, sweep, J.W. Turner (1♂, WSU); same data except, 5.viii.1985 (9♂, 1♀, WSU); same data except, 10.viii.1985 (4♂, 1♀, WSU); same data except, 22.vi.1986 (1♂, WSU); same data except, 26.viii.1986 (4♂, 7♀, WSU); Fields Spring State Park, 4 mi. S Anatone, Puffer Butte, small pond, 5.vii.1984, W. Turner (1♂, WSU); Benton County: West Richland, 19.v.1979, N.F. Woodley (1♂, USNM); Chelan County: Wenatchee, 8.vi.1919, ALM (1♂, USNM); Grant County: O’Sullivan Dam, 28.v.1955, M.T. James (1♂, WSU); same data except, 13.v.1956, H.G. Davis (1♂, WSU); Kitsap County: Colby, 18.viii.1910 (1♂, USNM); San Juan County: Friday Harbor, 30.v.1906, J.M. Aldrich (2♂, USNM); Whitman County: Colton, 14.vi.1980, G.C. Steyskal (4♂, USNM); Pullman, 13.ix.1908 (1♂, USNM); same data except, 2.viii.1965, Malaise, R.D. Akre (1♂, WSU); Steptoe Canyon, 10 mi SW Colton, 24.iv.1981, R.S. Zack (1♂, WSU); Steptoe Canyon, 8 mi SW Colton, 27.v–3.vi.1977, Malaise, R.D. Akre (2♂, WSU); Yakima County: ca 13 mi. SW Ellensburg, T16N R17E Sec 6, 13.vi.1989, R.S. Zack (1♂, 1♀, WSU). Wyoming: Albany County: Laramie, 16.vi.1958, FCH (2♂, FSCA); Teton County: Yellowstone National Park, Thumb Station, 16.vii.1923, ALM (1♂, USNM); same data except, Imperial Geyser, 2.viii.1934 (2♂, USNM).

Diagnosis. Males can be recognized by the strongly swollen fore tibia ( Fig. 86 ), very small excavation at apex of M 4 ( Fig. 91 ), and arista-like stylus with small, rounded apical lamella ( Fig. 80 ).

Redescription. Male. Wing length 3.0– 3.4 mm. Head: Frons with glabrous shiny blue-violet spot on either side of ocellar tubercle. Face silver, very narrow, triangular, 1 ommatidium wide or less at clypeus. Antenna ( Fig. 80 ) brown; scape laterally flattened, flared apically, slightly shorter than postpedicel; postpedicel elongate oval, nearly 2X as long as wide; arista-like stylus with inconspicuous microtrichia and small, rounded apical lamella. Palpus small, oval, brown with white apex and small white setulae. Thorax: Pleura brown with gray pruinosity; metepimeron concolorous with pleura, becoming yellowish above hind coxa. Legs: Foreleg ( Fig. 86 ): Yellow, except tarsus brown from near apical third of tarsomere 2. Tibia strongly swollen, with small posterodorsal seta at 1/3. Tarsomere 1 very short, about as long as wide. Tarsomere 2 with distally directed anterior seta, smaller posterior seta at apex. Tarsomere 3 not noticeably bowed, slightly broadened on apical half, with very short dense white dorsal microsetulae near apex. Tarsomere 4 with very short dense white dorsal microsetulae. Midleg: Yellow, except coxa infuscated at base and along anterodorsal edge, tarsus brown from near middle of tarsomere 1. Femur without small erect black ventral preapical setae. Tarsus ( Fig. 87 ) similar to other species in this group except slightly broader, tarsomere 2 with larger anteroapical lobe, with shorter and more strongly curved anterior setulae at apex of tarsomere 2 and on tarsomeres 3–4. Hindleg: Yellow, except coxa weakly infuscated around lateral seta, femur usually brown on apical third, tibia becoming brown apically, tarsus either wholly brown or brown from near middle of tarsomere 1. Femur ventrally with very short brown to black setae, with larger (less than femur width) ventral seta below anterior preapical seta. Tibia with ventral setae small, without longer or slender ventral setae near base. Wing ( Fig. 91 ): Posterior margin between apex of R 1 and M 4 rather flat, with very small lobe just before and small excavation at apex of M 4. Crossvein dm-m with longitudinal crease that crimps crossvein near M 4. Distal section of M 4 long, apically fading and distinctly arching toward wing tip, about 5X longer than crossvein dm-m. Abdomen: Tergites 2–4 broadly yellow laterally, brown dorsally and along posterior margins. Hypopygium: Postgonites with apical lobes sharply pointed, translucent light brown with black apex.

Female. Wing length 3.2–3.5 mm. Similar to male except as follows: Head: Face wider but relatively narrow (subequal to postpedicel width), nearly parallel-sided, gray. Antenna with postpedicel short, wider than long, with rounded apex, often weakly flattened; arista-like stylus unmodified. Palpus much larger, triangular, rounded apically, brown to nearly black with gray pruinosity, with longer yellow to brown setae. Thorax: Proepimeron usually with 3–5 small white hairs (one specimen has 1 hair). Legs: Unmodified, without specialized setae. Hind femur light brown dorsoapically. Hind tibia yellow. Hind tarsomere 1 yellow on basal half. Wing: Elongate oval, posterior margin evenly rounded. Crossvein dm-m without obvious longitudinal crease. Distal section of M 4 not fading apically or arching toward wing tip, about 3.5X longer than crossvein dm-m. Abdomen: Tergites 2–3 and usually tergite 4 with triangular ventrolateral yellow area.

Distribution and seasonal occurrence. Widely distributed in the western USA with one record from southern British Columbia, Canada ( Fig. 94 ). Adults have been collected April through October.

Remarks. Adults occur in shade of vegetation or stream banks in open habitats. Adults have sometimes been collected from hot springs and I have found adults by sweeping through rushes at the margins of hot springs.

Figures

FIGURE 94. Known geographical distributions of species in the Calyxochaetus fortunatus group.

FIGURES 77–91. Male antennae (lateral view), legs and wings of the Calyxochaetus fortunatus species group. 77. C. cascadia sp. nov. 78. C. fortunatus (Wheeler). 79. C. oreas (Wheeler). 80. C. vegetus (Wheeler). 81. C. leptofortunatus sp. nov. 82. C. cascadia sp. nov., fore tibia and tarsus, anterior view. 83. C. fortunatus, fore tibia and tarsus, anterior view.Arrow shows distally directed anterior seta at apex of tarsomere 2. 84. C. leptofortunatus sp. nov., fore tibia and tarsus, anterior view. 85. C. oreas, fore tibia and tarsus, posterior view. 86. C. vegetus, fore tibia and tarsus, posterior view. 87. C. vegetus, mid tarsus, ventral view. 88. C. cascadia sp. nov. 89. C. fortunatus. 90. C. oreas. 91. C. vegetus. Scale bars = 0.5 mm; arista-like styli approximately 1 mm long.