Acrosathe pacifica (Cole)

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 : 18-20

Acrosathe pacifica (Cole)

(Figs. 26–33, 51)

pacifica Cole (1923a:103 desc.) ( Thereva ); Irwin & Lyneborg (1981a:225 listing, comb. change) ( Acrosathe ). Type locality Pacific Grove, California. Holotype male in USNM.

Diagnosis. The male of Acrosathe pacifica is distinctive within the Nearctic Acrosathe in having the setae on the head and thorax dark brown to black. Acrosathe pacifica has be found in only Monterey and San Luis Obispo Counties of California, but the female is identical in appearance to those females of A. vanduzeei found north of San Francisco County (Del Norte, Humboldt, Sonoma counties).

Redescription of MALE. Variation (n=10).

Body length 6.5–9.6, 7.8 mm.

Head. Length 0.94–1.32, 1.07 mm. Ocellar tubercle dark reddish brown, pubescence gray; setae black, elongate. Eyes holoptic, separated by distance 0.1 times width of median ocellus; ommatidia smaller ventrally and laterally. Frons pubescence gray, dense, dark brown on dorsal fourth; setae black (occasionally yellowish brown to dark brown), elongate on ventral two-third extending lateral to antennal base which varies in color from yellowish brown to black. Antenna dark brown, pubescence gray, dense on scape; antenna/head length 0.74–0.95, 0.83; scape length 0.28–0.40, 0.36 mm, width 0.14–0.20, 0.16 mm, length/width 1.7–2.9, 2.3, scape/pedicel length 2.8–4.2, 3.4, scape/flagellum width 1.1–1.4, 1.2, setae black, elongate (occasionally yellowish brown), generally more abundant on ventral half, macrosetae dark reddish brown; pedicel length 0.10–0.12, 0.11 mm, width 0.12–0.16, 0.14 mm, length/width 0.6–0.9, 0.8 setae dark brown, short; flagellum length 0.38–0.52, 0.43 mm, width 0.12–0.14, 0.13 mm, length/width 2.9–3.7, 3.2, flagellum/scape length 1.0–1.4, 1.2. Parafacial pubescence gray; setae black (occasionally yellowish brown to dark brown) on lateral half. Maxillary palpus brown; length 0.40–0.64, 0.54 mm, width 0.10–0.14, 0.12 mm, length/width 3.3–5.2, 4.5; setae black (occasionally yellowish brown to dark brown), elongate. Genal setae black, (occasionally yellowish brown to dark brown), elongate. Occipital setae black (occasionally yellowish brown to dark brown), elongate; macrosetae dark brown to black (occasionally absent), scattered. Postocular macrosetae dark brown.

Thorax. Macrosetae dark reddish brown 3–4, 3 np, 1–2, 2 sa, 1 pa, 0–2, 1 dc. Mesonotum dark brown, pubescence brownish gray; vittae absent; setae dark brown to black, elongate (occasionally with dark brown erect setae and dark yellowish brown subappressed setae). Postpronotal setae dark brown to black, elongate. Prosternum setae dark brown, elongate. Pleuron pubescence gray, dense; setae dark brown to black, elongate on propleuron, anepisternum, katepisternum, laterotergite, metanepisternum, and scutellum. Wing. Membrane pale gray, veins pale brown (occasionally with brown margin at fork of R 4+5, r-m, around margin of discal cell, m-m, apical margin of bm and along Cu 2); length 5.3–7.0, 5.9 mm, width 1.8–2.3, 2.0 mm, length/width 2.7–3.0, 2.9; pterostigma brown, narrow. Cell m 3 open widely (occasionally closed, petiolate). Halter dark brown. Legs. Coxae dark brown, pubescence brownish gray, dense; setae dark brown, elongate, white on posterior half of hind coxa; apical macrosetae dark reddish brown, hindcoxa with 1 posterolateral macroseta. Femora dark brown, pubescence light gray; ventral setae dark brown, elongate, dorsal setae dark brown, appressed. Tibiae dark yellow becoming dark reddish brown apically. Tarsus 1 dark yellow, apex dark reddish brown; 2–5 dark reddish brown.

Abdomen. Dark reddish brown, pubescence white, dense; dorsal setae white, elongate, appressed (on specimens from San Luis Obispo County) or dark brown to black (on specimens from Monterey County, occasionally dark yellowish brown); lateral setae white erect. Terminalia (MEI 100990) dark reddish brown. Tergite 8 (Fig. 26), setae white, elongate. Sternite 8 (Fig. 27) rectangular, anterior margin truncate, sides rounded; posterior margin slightly emarginate medially; setae white, separated medially on posterior margin. Epandrium (Fig. 26) dark brown, quadrate; longer medially than wide; posterolateral margin pointed; setae white. Cerci (Fig. 26) ending distal to apex of hypoproct. Hypoproct (Fig. 26) pale whitish yellow; posterior margin rounded, ending basal to apex of cerci at posterolateral margin of epandrium. Gonocoxite ventral view (Fig. 27), median margin broadly emarginate, posterior margin scalloped; setae white, macrosetae dark reddish brown; lateral view (Fig. 28) oblong, tapering posteriorly to blunt point; setae white with several dark reddish brown apical macrosetae. Gonostylus (as in Fig. 21 ). Aedeagus with dorsal apodeme (Fig. 29) broadly expanded laterally, anterior half narrowed; ventral apodeme (Fig. 30) broad, sides parallel, not reaching anterior margin of dorsal apodeme; distiphallus dorsal view (Fig. 29) tapered posteriorly, lateral view (Fig. 31) sinuate; AAP (Fig. 31) short, reaching about one-half length of distiphallus; ejaculatory apodeme (Fig. 29) extending beyond anterior margin of dorsal apodeme.

FEMALE. Similar to male except as follows. Variation (n=10).

Body length 7.7–10.0, 9.0 mm.

Head. Length 1.08–1.23, 1.19 mm. Frons pubescence brownish gray, white on ventral third with dark brown pubescent, transverse bar (Fig. 32); setae dark brown, white on ventral third. Antennal/head length 0.65–0.85, 0.77; scape length 0.32–0.44, 0.39 mm, width 0.16–0.22, 0.18 mm, length/width 1.8–2.4, 2.1, scape/pedicel length 3.2–5.0, 3.9, scape/flagellum width 1.1–1.4, 1.2, setae white; pedicel length 0.08–0.12, 0.10 mm, width 0.14–0.17, 0.15 mm, length/width 0.5–0.9, 0.7, setae dark brown, short; flagellum length 0.36–0.50, 0.42 mm, width 0.14–0.17, 0.15 mm, length/width 2.1–3.1, 2.8, flagellum/scape length 0.9–1.2, 1.1. Parafacial setae white. Maxillary palpus length 0.48–0.76, 0.57 mm, width 0.10–0.14, 0.12 mm, length/ width 4.0–5.5, 4.9; setae white. Genal setae white. Occipital setae white.

Thorax. Macrosetae 3 np, 1–2, 2 sa, 1–2, 1 pa, 1–2, 2 dc. Mesonotal setae white, appressed. Postpronotal setae white. Prosternum setae white. Pleural setae white. Wing. Membrane pale whitish gray, veins pale brown; length 5.3–7.7, 6.6 mm, width 2.0–2.5, 2.1 mm, length/width 2.7–3.3, 2.8; cell m 3 closed, petiolate. Legs. Coxal setae white.

Abdomen. Pubescence grey with narrow band of dark brown pubescence across anterior margin of tergites 2–4; dorsal setae white elongate appressed. Terminalia (MEI 012278). Furca (Fig. 33) oval, anterior margin rounded, length 0.49 mm, width 0.43 mm; anterolateral projection short.

Immature Stages. Three males (MEI 037015, 130039, 136590) and 3♀ (MEI 130036, 157891, 157892) were reared from larvae collected at Salinas River State Beach, California from dunes; 1♂ (MEI 083171) and 2♀ (MEI 083136, 083154) were reared from larvae collected 1.6 km SW Moss Landing, California ; and 1♂ (MEI 107901) was reared from larvae collected at Rancho Guadalupe County Park, California .

Distribution. Acrosathe pacifica is known from California ( Fig. 51 ).

Habitats and Phenology. Acrosathe pacifica has been sifted as larvae from sand or hand-netted or collected as adults in Malaise traps in coastal dunes. Adults have been collected in February and from April through August.

Specimens examined. Type specimens. The holotype male of Thereva pacifica Cole is labeled "Pacific Grove, California, May 8, 1906, J. M. Aldrich " and is in the USNM ( Type No. 25938). Other specimens. UNITED STATES. CALIFORNIA. Colusa County. Williams [39.155, -122.148], 24.V.1954, Grigarick, A.A., 1♂ MEI 011616 ( UCDC) . Monterey County. 17 Mile Drive [36.605, -121.945], 17.V.1959, 3♂ MEI 011917–8, 011921, 1♀ 011896 ( EMEC) ; Asilomar [36.621, -121.935], 10.V.1959, Burdick, J., 8♂ MEI 011902–7, 011919–20, 2♀ 011897, 011901 ( EMEC) ; Forest Camp on Tassajara Road [36.31, -121.558], 14.VI.1958, Bartholomew, P.S., 1♂ MEI 132114 ( CAS) ; Monterey [36.609, -121.91], 20.V.1956, Wasbauer, M., 2♂ MEI 011908–9 ( EMEC) ; Barnes , A.M., 1♂ MEI 083639 ( MEIC) ; Moss Landing , [36.8, -121.788], 27.V.1969, Irwin , M.E., Andrews, F. G., 14♂ MEI 012280, 012282–91, 012293, 012296, 012299, 3♀ 012277–9 ( MEIC) ; Pacific Grove [36.618, -121.916], 7.V.1906, Aldrich, J.M., 1♂ MEI 113592, 1♀ 113594 ( USNM) , sand dune;?. V.1906, Aldrich, J.M., 1♂ MEI 113593, 1♀ 113144 ( USNM) ; 31.II.1954, Wasbauer, M., 1♂ MEI 011916 ( EMEC) ; 29.V.1954, Wasbauer, M., 1♀ MEI 01190 ( EMEC) ; 16.V.1959, Stage, G.I., 3♂ MEI 011922, 011932–3, 2♀ 011898–9 ( EMEC) ; Seaside , [36.611, -121.851], 24.VI.1965, Irwin , M.E., 2♂ MEI 012298, 012518 ( MEIC) ; Salinas River State Beach [36.793, -121.792], 30.V.2001, Holston, K.C., 2♂ MEI 157889–90 ( INHS) , dunes; 25.VI.2001, Holston, K.C., Alvarez, A., 3♂ MEI 130037, 130039, 136590, 3♀ 130036, 157891, 157892 ( INHS) , sifted dunes; 1.6 km SW Moss Landing , [36.804, -121.786], 17.IV.1990, Webb, D.W., Irwin , M.E., 1♂ MEI 083171, 2♀ 083136, 083154 ( INHS) , sieved. San Luis Obispo County. Pismo Beach [35.143, -120.64], 7.VIII.1930, Winburn, T.F., Painter, R.H., 1♂ MEI 012325 ( MEIC) ; 29.VIII.1945, Melander, A.L., 1♂ MEI 113762 ( USNM) ; 13.V.1956, Cox, J.W., 1♀ MEI 053746 ( MEIC) ; Wilcox , J., 1♂ MEI 053743 ( UCR) ; 26.VII.1966, Wilcox, J., 1♀ MEI 012465 ( UCR) ; 8.VII.1969, Wilcox, J., 2♂ MEI 012395–6, 1♀ 012464 ( UCR) ; 24.VI.1970, Wilcox, J., 1♂ MEI 012398 ( UCR) ; Rancho Guadalupe County Park [34.966, -120.651], 21.VI.1997, Holston, K.C., 1♂ MEI 107901 ( INHS) , sieved foredune hillocks; 1.6 km N Oceano [35.083, -120.6], 7.IX.1965, Wilcox, J., 4♂ MEI 012374, 012385–6, 012390 ( UCR) ; Grover City [35.122, -120.62], 4.VII.1956, Hurd, P.D., 2♂ MEI 011910, 011931, 1♀ 011911 ( EMEC) ; 13.VIII.1957, Linsley, E.G., 3♂ MEI 011925, 011927–8 ( MEIC) ; Guadalupe-Nipomo Dunes , W border Teixeira Farms [36.199, -121.147], 20.VI.1997, Holston, K.C., 2♂ MEI 100990, 101026 ( INHS) ; Morro dunes, 9.VI.1945, Melander, A.L., 1♂ MEI 113751 ( USNM) ; Morro Bay [32.368, -120.851], 16.VI.1947, 4♂ MEI 113750, 113755, 113768–9 ( USNM) ; 26.VI.1963, Hall, J.C., 1♂ MEI 012355 ( UCR) ; 26.IV.1968, Opler, P.A., 2♂ MEI 012102, 012104 ( EMEC) ; Oceano [35.099, -120.611], 11.VIII.1962, Schlinger, E.I., 1♂ MEI 053744, 2♀ 012480, 053745 ( UCR) ; 16.VII.1970, Wilcox, J., 1♂ MEI 012375 ( UCR) ; Oso Flaco Dunes [35.029, -120.621], 9.V.1987, Russell, D.E., 2♀ MEI 083184–5 ( MEIC) ; 13.VII.1959, Spore, R.W., 2♂ MEI 012141, 012625 ( EMEC) ; 22.VI.1965, Irwin , M.E., 1♂ MEI 012566 ( MEIC) , coastal dunes; 29.VI.1967, Irwin , M.E., Cronin, T., Larisch, S., 2♂ MEI 012554, 012568 ( MEIC) , coastal dunes; 23.VIII.1968, Irwin , M.E., 1♂ MEI 012565 ( MEIC) , coastal dunes; 16.IV.1990, Webb, D.W., Irwin , M.E., 1♀ MEI 083155 ( INHS) , sifted; 16.VI.1996, Russell, D.E., 1♀ MEI 083187 ( MEIC) ; Guadalupe-Nipomo Dunes Preserve , Oso Flaco State Park [35.029, -120.617], 17.VI.1997, Irwin , M.E., 1♂ MEI 101036 ( MEIC) ; Pismo Beach State Park [35.108, -120.63], 15.VII.1967, Irwin , M.E., 1♂ MEI 012556 ( MEIC) , coastal dune; Pismo Beach [35.175, -120.647], 1.VI.1992, Skevington, J.H., Goering, A., 1♀ MEI 078056 ( MEIC) , coastal dunes.

Figures

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.

FIGURE 50–53. Distribution map. 50. Acrosathe bimaculata closed circle, Arenigena floridensis closed triangle, Litolinga tergisa open circle. 51. Acrosathe falcata closed circle, Ac. pacifica open circle. 52. Acrosathe otiosa. 53. Acrosathe vanduzeei.