Arenigena semitaria (Coquillett)

Webb, Donald W., 2009, A revision of the genera Acrosathe Irwin and Lyneborg, Arenigena Irwin and Lyneborg, and Litolinga Irwin and Lyneborg (Diptera: Therevidae: Therevinae) from the Nearctic Region, Zootaxa 2091 (1), pp. 1-67 : 53-55

Arenigena semitaria (Coquillett)

( Figs. 88–96 )

semitaria Coquillett (1893a:197 key, 198 male desc., 199 fem. desc.), Aldrich (1905:250 cat.), Kröber (1912: 248 male key, 250 fem. key, 255 spec. list; 1913: 43 male key, 44 fem. key, 61 dist.; 1914: 60 male key, 62 fem. key, 64 desc., dist.), Cole (1923a: 86 male key, 88 fem. key, 93 notes, Figs. 128 fem. frons, 138 ant.; 1923b:462 add. dist.; 1965:354 cat.) ( Thereva ); Irwin and Lyneborg (1981a:198 Figs. 19 male head, 21 ant., 240 comb. change, spec. list, 239 Figs. 148– 155 male genit.), Holston (2004:62 nom.) ( Arenigena ). Type locality southern California. Lectotype male in USNM.

Diagnosis. Arenigena semitaria is similar to A. albiseta and A. floridensis in the male having the inner gonocoxal process bilobed ( Fig. 90 ). It differs from A. albiseta and A. floridensis in having the wing veins and cross-veins with a brown margin; the proepimeron lacking setae; the male sternite 8 with setae absent medially on posterior margin ( Fig. 89 ); the gonostylus ( Fig. 91 ) with short, dark brown macrosetae apically and with an apical tuft of elongate setae; and the furca ( Fig. 95 ) with anterior margin tridentate in appearance.

Redescription of MALE. Variation (n=10).

Body length 7.0–8.2, 7.7 mm.

Head. Length 0.90–1.08, 1.00 mm. Ocellar tubercle dark reddish brown, pubescence gray, dense; setae pale yellow, short. Frons pubescence white, dense. Antenna yellow, second and third flagellomeres dark brown; antenna/head length 0.52–0.71, 0.66; scape length 0.16–0.20, 0.19 mm, width 0.12–0.16, 0.14 mm, length/width 1.1–1.7, 1.4, scape/pedicel length 1.6–2.5, 2.3, scape/flagellum width 0.7–0.9, 0.7, setae white yellow, short; pedicel length 0.08–0.10, 0.08 mm, width 0.12–0.16, 0.14 mm, length/width 0.5–0.7, 0.6; flagellum (apical portion of first flagellomere short, thick), length 0.35–0.44, 0.41 mm, width 0.18–0.20, 0.19 mm, length/width 1.9–2.4, 2.2, flagellum/scape length 1.9–2.5, 2.2. Parafacial pubescence yellowish gray. Gena pubescence whitish gray; setae white, elongate. Maxillary palpus yellow; length 0.38–0.48, 0.45 mm, width 0.06–0.08, 0.07 mm, length/width 5.5–7.5, 6.1; setae white to pale yellow, elongate. Occipital setae white, elongate abundant dorsally.

Thorax. Macrosetae 3 np, 2 sa, 1–2 dc. Mesonotum dull brownish gray; setae white, elongate. Pleuron pubescence gray, dense; setae white, elongate on propleuron, proepimeron (occasionally absent), anepisternum, katepisternum (setae in band along anterior margin), laterotergite, metanepisternum, and scutellum. Wing. Membrane pale whitish gray, veins brown with brown spot at fork of R 4+5, r-m, apex of discal cell, apex of cells bm and cup; length 5.7–6.8, 6.4 mm, width 1.8–2.6, 2.3 mm, length/width 2.6–3.2, 2.8; pterostigma dark brown. Legs. Coxae pubescence white, dense; setae white, elongate. Femora dark reddish brown, pubescence white; ventral setae white, elongate, dorsal setae white, appressed. Tibiae yellow. Tarsi 1 dark yellow; 2–5 brown.

Abdomen. Pubescence white, dense; dorsal setae white, elongate, erect, abundant; lateral setae white, elongate. Terminalia (MEI 113211) brown. Tergite 8 ( Fig. 88 ), setae pale yellow. Sternite 8 ( Fig. 89 ), rectangular, sides rounded, posterior margin slightly emarginate; setae pale yellow, separated medially on posterior margin. Epandrium ( Fig. 88 ) quadrate; posterolateral margin short, broadly pointed; setae yellow. Hypoproct ( Fig. 88 ), posterior margin slightly emarginate. Gonocoxite ventral view ( Fig. 89 ) quadrate, tapering posteriorly to blunt point, setae yellow, macrosetae yellow; lateral view ( Fig. 90 ), rounded ventrally, extending posteriorly to blunt point, inner gonocoxal process, bilobed, dorsal lobe pointed with yellow setae, ventral lobe rounded, setae absent. Gonostylus dorsal view flattened laterally; lateral view ( Fig. 91 ), narrow, pointed dorsally with numerous dark reddish brown macrosetae apically. Aedeagus with dorsal apodeme ( Fig. 92 ) broad laterally, becoming narrow anteriorly, anterior margin truncate; ventral apodeme ( Fig. 93 ), broad, sides parallel; distiphallus dorsal view ( Fig. 92 ) narrow, tapered posteriorly; lateral view ( Fig. 94 ) thick basally, elongate, sigmoid; ejaculatory apodeme ( Figs. 92–93 ) reaching anterior margin of dorsal apodeme.

FEMALE. Similar to male except for following. Variation (n=6).

Body length 6.8–10.0, 8.8 mm.

Head. Length 0.94–1.18, 1.01 mm. Frons pubescence whitish to yellowish gray, dense; setae pale yellow, short, appressed. Antenna/head length 0.59–0.72, 0.68; scape length 0.18–0.24, 0.20 mm, width 0.14–0.18, 0.15 mm, length/width 1.1–1.4, 1.3, scape/pedicel length 2.3–2.7, 2.4, scape/flagellum width 0.8–0.9, 0.8; pedicel length 0.08–0.10, 0.08 mm, width 0.14–0.18, 0.15 mm, length/width 0.5–0.6, 0.6; flagellum length 0.36–0.4, 0.40 mm, width 0.16–0.20, 0.19 mm, length/width 2.0–2.4, 2.2, flagellum/scape length 1.8–2.4, 2.0. Maxillary palpus length 0.46–0.50, 0.47 mm, width 0.08–0.10, 0.09 mm, length/width 5.0–5.8, 5.6.

Thorax. Macrosetae 3 np, 2 sa, 1–2 dc. Wing. Length 6.2–7.8, 7.0 mm, width 2.0–2.7, 2.4 mm, length/ width 2.7–3.1, 2.9.

Abdomen. Yellowish brown, pubescence white (occasionally dark reddish brown); dorsal setae pale yellow, appressed on tergites 1–4, dark reddish brown, short on tergites 5–8. Terminalia (MEI 170267). Furca

( Fig. 95 ), oval, anterior margin broad, expanded anteriorly, anterolateral projection short; length 0.54 mm, width 0.36 mm.

Immature stages. Unknown.

Distribution. Arenigena semitaria is known from Arizona, California, Idaho, Nevada, Oregon, Utah, and Wyoming ( Fig. 96 ).

Habitats and Phenology. Arenigena semitaria has been hand-netted or collected in pitfall or Malaise traps set in dry riverbeds or sand dunes. Adults have been collected from May through August.

Specimens examined. Type specimens. Coquillett described Thereva semitaria based on 11 males and four females deposited in the USNM ( Type No. 10421). Only one male specimen of this series could be located. This syntype male is labeled "5 31, Los Angeles Co. Cal., Coquillett Collection" and is in the USNM ( Type No. 10421) (MEI 114021). This lectotype is designated in order to fix the concept of Thereva semitaria Coquillett and to ensure universal and consistent interpretation of the same. Other specimens. UNITED STATES. ARIZONA. Navajo County . 30.6 km SW Kayenta [36.533, -110.448], 1981m, 16.VI.1933, Hultgren, H.N., 2♂ MEI 156338–156339 ( CAS) . CALIFORNIA. La Puerta, 1♂ MEI 156340 ( CAS) . Kern County. 11.3 km NW Frazier Park [34.895, -119.016], 1.VII.1965, Gardner, M.R., 1♂ MEI 119049 ( UCDC) ; 16.1 km W Tehachapi, Bear Spring Valley [35.128, -118.59], 14.VII.1991, Powell, J., 1♂ MEI 119004 ( UCDC) . Los Angeles County.?.31.V., 1♂ MEI 114021 ( MEIC) ; Claremont [34.097, -117.719], Baker, 1♂ MEI 115633 ( USNM) . Monterey County. Paraiso Springs [36.331, -121.368], 27.V.1927, Slevin, L.S., 1♂ MEI 119031 ( MEIC) . Riverside County. Santa Rosa Mountain [33.538, -116.461], 27.V.1946, Knull, D.J., Knull, J.N., 1♀ MEI 114602 ( OSU) . San Bernardino. 9.7 km E Yermo [34.905, -116.732], 27.VIII.1952, Leech, H.B., Green, J.W., 1♂ MEI 156341 ( CAS) , dry bed Mojave River. Santa Barbara County. Orcutt [34.873, -120.425], 22.VIII.1948, Wirth, W.W., 1♂ MEI 113211 ( USNM) . IDAHO. Bonneville County. Idaho Falls, Ammon Sand Dunes [43.467, -112.033], 22–26.VII.1936, 1♂ MEI 119043 ( UMSP) . Butte County. 6.4 km SW Howe [43.743, -113.045], 24.VI.1987, Johnson, J.B., 1♂ MEI 170260 ( MEIC) . Cassia County. 11.3 km SE Malta [42.306, -113.368], 21.VII.1957, Barr, W.F., 1♂ MEI 119041 ( WFBM) ; 14.5 km E Malta [42.306, -113.238], 11.VII.1981, Wight, R.P., 1♂ MEI 079939, 1♀ 079937 ( INHS) , pitfall trap; 15.VII.1981, 1♂ MEI 079934 ( WFBM) ; 29.VII.1981, 1♂ MEI 079935 ( WFBM) , pitfall trap; 29.VII.1981, 1♂ MEI 079936 ( WFBM) , pitfall trap; Bridge [42.13, -113.34], 6.VII.1978, Knowlton, G.F., 2♂ MEI 072748, 072780 ( EMUS) ; Malta [42.306, -113.368], 20.VI.1953, O’Connell, T.B., 1♂ MEI 119002 ( WFBM) ; 24.VII.1961, Barr, W.F., 2♂ MEI 119032, 119038 ( WFBM) . Elmore County. 24.2 km W Mountain Home [43.125, - 115.909], 956m, 16.VI.1955, Barr, W.F., 1♀ MEI 119059 ( WFBM) . Gooding County. 8.1 km N Bliss [43, - 114.949], 7.VI.1955, Gillaspy, J.E., 3♂ MEI 119007, 119044 ( INHS) , 119036 (WFBM). Oneida County. 8.1 km NW Holbrook [42.213, -112.705], 13.VII.1972, Knowlton, G.F., Hanson, W.J., 1♀ MEI 072781 ( EMUS) .

Owyhee County. 3.2 km NW Murphy [43.239, -116.572], 25.V.1963, Gittins, A.R., 2♂ MEI 119029, 119037 ( WFBM) . Twin Falls County. Hollister [42.353, -114.574], 26.VI.1931, Fox, D.E., 1♂ MEI 102058 ( MEIC) ; Frain N of Artesian [ Artesian City] [42.2502, -114.0940], 24.VI.1917, Burrill, A.C., 1♂ MEI 101861 ( WSU) . NEVADA. Humboldt County. Orovada [41.57, -117.784], 7.VI.1961, Bechtel, R.C., 6♂ MEI 118998, 170259, 118996, 119030, 119034–5 ( MEIC) ; Winnemucca [40.973, -117.735], 9.VI.1960, Bohart, G.E., 2♂ MEI 119005, 119047 ( EMUS) . Pershing County. Dago Pass [ McKinney Pass ] [40.221, -117.7841], 670m, 20.VII.1972, Nishida, G.M., 2♂ MEI 076953–4 ( NVDA) . White Pine County . 32.2 km NE Ely [39.455, - 114.675], 13.VII.1961, Lauderdale, R.W., 4♂ MEI 076964–5, 076972–3 ( NVDA) . OREGON. Harney County. [42.603, -118.382], 1.VII.1979, Lightfoot, Cobb, 2♂ MEI 114708, 119028 ( UOIC) , sand dunes; Alvord Dunes [42.415, -118.382], 11.VII.1979, Cobb, N., 1♂ MEI 119042 ( UOIC) ; Alvord Well #3 [42.56, - 118.362], 1.VI.1979, Lightfoot, Cobb, 1♂ MEI 119001 ( UOIC) , sand dunes; 19.VI.1979, 1♂ MEI 118997 ( UOIC) , sand dunes; Harney Lake dunes , 11.4 km W Junction 205, 18.V.1978, Cobb, N., 1♂ MEI 118999 ( UOIC) ; Whitehorse Ranch [42.338, -118.239], 13.VIII.1967, Goeden, K., 1♂ MEI 119046 ( ODAC) ; Willow Creek , W Whitehorse Ranch [42.338, -118.239], 13.VIII.1967, Goeden, K., 1♀ MEI 119008 ( ODAC) .

Malheur County. 9.7 km SW Vale [43.922, -117.313], 4.VIII.1971, Goeden, K.J., 1♂ MEI 119033 ( ODAC) . UTAH. Box Elder County. 1.VIII.1967, Capelle, K.J., 16♂ MEI 072741, 072749, 072752–64, 072766 ( EMUS) ; 27.4 km SW Snowville [41.76, -112.894], 2.VI.1976, 1♂ MEI 075317 ( EMUS) , Malaise trap, grass; 17.VI.1976, 1♂ MEI 075316 ( EMUS) , pitfall trap; 27.VII.1976, 1♂ MEI 075314 ( EMUS) , Malaise trap; 3.VIII.1976, 1♂ MEI 075315 ( EMUS) , Malaise trap. Millard County. Pahvant, 8.VII.1965, Knowlton, G.F., 1♂ MEI 072776 ( EMUS) . Uintah County . 8.1–16.1 km SW Bonanza [39.931, -109.222], 1524–1707m, 9.VI.1982, Schwartz, M.D., 1♂ MEI 11900, 1♀ 170267 ( AMNH) . Washington County . Leeds Canyon [37.295, -113.42], 21–23.VII.1981, Hanson, W.J., 1♂ MEI 072769 ( EMUS) . WYOMING. Green River [41.533, -109.467], 1859m, 2.VII.1920, 1♂ MEI 119039 ( MEIC) . Sweetwater County . 40.3 km S Bitter Creek , 22.VIII.1931, 1♂ MEI 078444 ( CMNH) ; near Tipton, Red Desert [41.628, -108.263], 27.VI.1978, Bullington, S.W., 1♂ MEI 072331 ( CSCA) .

Figures

FIGURES 88–95. Arenigena semitaria. 88. Tergite 8, epandrium, cerci. 89. Sternite 8, gonocoxite ventral view. 90. Gonocoxite, lateral view. 91. Gonostylus lateral view. 92. Aedeagus, dorsal view. 93. Aedeagus, ventral view. 94. Aedeagus, lateral view. 95. Female internal reproductive organs. Scale = 0.1 mm.

FIGURE 96–97. Distribution map. 96. Arenigena bajaensis, open circle, Ar. semitaria closed circle. 97. Arenigena marcida closed circle, Litolinga acuta open circle.

FIGURES 18–25. Acrosathe otiosa. 18. Tergite 8, epandrium, cerci. 19. Sternite 8, gonocoxite ventral view. 20. Gonocoxite, lateral view. 21. Gonostylus dorsal view. 22. Aedeagus, dorsal view. 23. Aedeagus, ventral view. 24. Aedeagus, lateral view. 25. Female internal reproductive organs.