Lasiopogon esau McKnight

Mcknight, Tristan A. & Cannings, Robert A., 2020, Molecular phylogeny of the genus Lasiopogon (Diptera: Asilidae) and a taxonomic revision of the bivittatus section, Zootaxa 4835 (1), pp. 1-115: 57-59

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Lasiopogon esau McKnight

sp. nov.

Lasiopogon esau McKnight   sp. nov.

Diagnosis. ( Fig. 31 View FIGURE 31 ) A small to medium dusty grey species from northwestern California; mystax variable but usually mostly black with some white setae ventrally; setae on scape white, on pedicel black; scutal macrosetae black, finer setae black except white along anterior margin; scutum tomentum grey to brown with dorsocentral and acrostichal stripes faint; tergites with brown tomentum basally, grey over apical 40–60%, tomentum along dorsal midline thin and subshining, leaving pattern indistinct; lateral setae on tergites white. Male terminalia cuticle dark brown with setae long, erect, and dense; epandrium in dorsal view appears tapered, wider at base than apex; gonostylus in lateral view flattened, longer than tall; phallus with dorsal carina flattened, extending apically almost equidistant to gonopore like a squared-off porpoise fin. Ovipositor dark brown/black; acanthophorite spines black.

Description. Body length ♂ 8.0– 8.9mm; ♀ 7.0– 10.2mm. Head. HW ♂ 1.89–1.99mm; ♀ 1.65–2.27mm. FW ♂ 0.39–0.45mm; ♀ 0.33–0.49mm. VW ♂ 0.73–0.85mm; ♀ 0.66–1.05mm. VW/HW = ♂ 0.39–0.43; ♀ 0.37–0.46. FW/VW = ♂ 0.48–0.57; ♀ 0.47–0.57. VD/VW = ♂ 0.11–0.16; ♀ 0.12–0.14. GH/GL = ♂ 0.33–0.49; ♀ 0.38–0.47. Face silver-grey, vertex brown-grey. Ventral setae (beard, labium, palps) white; dorsal setae (frontal, orbital, ocellar, occipital) black; mystax usually mostly black, frequently with a few setae white ventrolaterally, occasionally ventral quarter white, rarely white predominates mystax. Occipital macrosetae fine, posterior to frons longest (to 0.6mm) and strongly curved anteriorly, lateral macrosetae short, straight. Frontal setae fine, long (reach midpoint of postpedicel); orbital setae also fine and long, curving over eye margin; ocellar setae indistinct among setae. Antennae. Black, with thin grey tomentum. Setae on scape white, on pedicel black; no setae on postpedicel. Postpedicel short, rectangular; stylus long. WPP/LPP = ♂ 0.25–0.35; ♀ 0.30–0.37. LAS/LPP ♂ 0.48–0.63; ♀ 0.48–0.66. Thorax. Prothorax grey, with white setae; postpronotal lobes grey, the lateral angle light brown, setae white. Scutum tomentum grey-brown; dorsocentral stripes faint brown; acrostichal stripes faint grey. Macrosetae and setae of scutum black except a few short white setae on anterior margin of scutum; dorsocentral macrosetae with 5–6 anterior to suture (to 0.9mm), posterior dorsocentrals 3–5; postalars 2–3, with a few short setae; supra-alars 2, with 1–2 short setae; presuturals 2–3; posthumerals 0–1. Scutellar tomentum brown; apical macrosetae black, abundant (10+ on each half), mixed with other long setae. Pleural tomentum brownish grey. Katatergite setae black, long, 7–10, with a few short white setae; katepisternal setae white; anepisternal setae 6, black (to 0.6mm), a few black setae along dorsal margin and 1–2 white setae in posteroventral corner; anepimeron with 0–1 fine white setae. Legs. Cuticle dark brown/black and covered in thin grey tomentum though bare and reddish-black at femur joints. No coxal peg. Coxae with white setae; fine setae of femur and tibia white, fine setae of tarsi black; main macrosetae black except on basal half of femur. Ventral setae on femur slightly longer than femur width; dorsoapical macrosetae on profemur fine, indistinct among other setae, 8–11; on mesofemur and metafemur stronger, 4–7 and 12–16 respectively. Protibia with ventral macrosetae 3 times longer than tibial width; very faint patch of pale yellow setae on inside of protibia. Claws chestnut over basal 70%, apically black. Wings. Veins light brown; membrane hyaline, slightly brown when viewed obliquely. DCI = 0.35–0.41. Halter knob cream, without spot, stem light brown. Abdomen. Male. Tergite cuticle dark brown/black; thin brown tomentum on tergite bases; grey tomentum in bands covering apical 40–60% of each tergite (segment 1 completely covered except basomedially), brown cuticle subshining along midline leaving brown/grey pattern indistinct. Tergite 1 with 1–5 black and 2–5 white lateral macrosetae; lateral setae white, on tergites 1–3 as long as halter stem, on tergites 4–7 as long as scape + pedicel; dorsal setulae short, brown. Sternite tomentum grey, setae white. Female. As in male, except tomentum along dorsal midline thicker; lateral setae on tergites 5–7 black, and no longer than scape. Male genitalia. Epandrium and hypandrium/gonocoxite complex cuticle dark brown, covered in thin grey tomentum except medially on hypandrium; setae dark brown/black, very long, erect and dense; setal brush dark brown. Epandrium elongate, in lateral view the width about 48% the length, widest in basal third, ventral margins gently sinuate, dorsal margin straight; apex rounded into weak ventral subapical tooth. In dorsal view, epandrium appears tapered, wider at base than apex; medial margins moderately curved, curvature starts about 37% from base; basal sclerite prominent. Phallus paramere sheath dorsally 54% the length of phallus; paramere sheath with short buttress-like ventral flange basally; dorsal carina flat, extended apically almost equidistant to gonopore like a squared-off porpoise fin, leaving a broad gap between apices. Ejaculatory apodeme in lateral view strongly bent dorsally in basal quarter, with broad dorsal carina. Subepandrial sclerite with triangular central unsclerotized area in basal 72%; spines parallel-sided, blunt, sparsely distributed, slightly more densely basomedially and apically.

Female genitalia. Undissected: Cuticle dark brown, except pale reddish brown at base of hypogynial valves and usually with sternite 8; tergite and sternite 8 with short white setae; lateral lobe setae short, black; cerci brown with pale setae; acanthophorite spines black.

Type Material. HOLOTYPE ♂ labelled: “[rectangular white label] CALIF: Trinity Co. / Junction City / V-4- 1978 / T. R. Haig coll.”; “[rectangular green label] FISH ”. Our type label “[red and black bordered label] HOLOTYPE/ Lasiopogon esau   / des. T.A. McKnight 2017” has been added. Deposited at USNM.  

PARATYPES (146 specimens designated): U.S.A.: CALIFORNIA: [no loc], Baron (3♂ OSUC, OSUC 194421 View Materials OSUC 194422 View Materials , OSUC 194426 View Materials )   ; Humboldt Co., Fort Seward [40.226 -123.646], 30.v.1935, E.W. Baker (1♀ FISH) GoogleMaps   ,, E.W. Baker (1♀ FISH)   ; Richardson Grove , 5 mi N [40.058 -123.785], 30.iv.1959, T.R. Haig (1♂ 2♀ FISH) GoogleMaps   ; S Fork Eel River, Hwy 254 1.2km N of Miranda, sandbars at forest edge, 40.248 -123.824, 10.v.1995, R.A. Cannings, H. Nadel (3♂ 4♀ RBCM, RBCM ENT 010-002769 View Materials , RBCM ENT 010-002770 View Materials ) GoogleMaps   ; Lake Co., Rice Fork Eel River near Bear Creek [39.327 -122.871], 23.iv.1987, Baumann, Stark, Nelson, Wells (6♂ 1♀ BYU, 1♂ TAM) GoogleMaps   ; Marin Co., San Antonio Creek, San Antonio Rd 4.5 mi S of Petaluma, 38.17899 -122.62826, 15.iii.2014, T.A. McKnight (1♀ [1 EtOH] UMMZ) GoogleMaps   ; Mendocino Co., Branscomb , 3 mi N, NCCRP [39.691 -123.655], 8.v.1976, M.M. Helena (1♂ EMEC) GoogleMaps   , 21–23.v.1982, C. Besette (1♀ BEZA)   , 18–21.v.1984, D.J. Sandri (1♂ 2♀ EMEC)   ; Branscomb , 5 mi N, NCCRP [39.719 -123.652], 24.v.1976, J. Powell (1♂ 1♀ [1 pr in cop] EMEC) GoogleMaps   , 24–25.v.1976, R. Wharton (1♂ 1♀ EMEC)   ; Hopland [38.969 -123.117], D.D. Munroe (2♀ CNC) GoogleMaps   ; Russian River near Hopland [38.954 -123.102], 3.iv.1968, J. Powell (3♂ 1♀ EMEC, 1♂ RBCM), 4.v.1968, W.J. Turner (1♂ ESUW) GoogleMaps   , 9.v.1970, J.A. Powell (1♂ 1♀ EMEC)   ; Napa Co., Samuel Springs, Lake Berryessa W shore [38.605 -122.311], 29.iii.1956, R.M. Bohart (2♀ CAS) GoogleMaps   ; Sonoma Co., Duncan Mills , 2 mi E [38.455 -123.050], 13.v.1960, T.R. Haig (1♀ FISH) GoogleMaps   ; Hacienda [38.507 -122.929], 20.v.1961, C. Slobodchikoff (1♂ FISH) GoogleMaps   ; Healdsburg [38.623 -122.837], 7.v.1974, G. Pereira (1♀ CAS) GoogleMaps   ; Trinity Co., Hayfork, Hayfork Creek near Forest Ave , 40.54509 -123.16681, 24.v.2016, T.A. McKnight (1♀ [1 EtOH] UMMZ) GoogleMaps   ; Hayfork Ranger Station [40.547 -123.168], 23.v.1973, J. Doyen (1♂ EMEC, 1♀ RBCM), J. Powell (4♂ 3♀ EMEC, 1♂ RBCM) GoogleMaps   ; Hayfork , 2300’ [40.552 -123.1801], 25.v.1973, S.L. Szerlip (1♂ 1♀ [1 pr in cop] EMEC) GoogleMaps   ; Hayfork , 4 mi S [40.498 -123.174], 18/ 19.v.1973 (1♀ EMEC) GoogleMaps   ; Junction City [40.732 -123.056], 1.v.1976, T.R. Haig (2♂ FISH) GoogleMaps   , 21.iv.1977, T.R. Haig (1♂ FISH)   , 4.v.1978, T.R. Haig (12♂ 12♀ FISH, 1♀ TAM, 1♂ UMMZ), 25.v.1983, T.R. Haig (4♂ FISH)   , 23.iv.1984, T.R. Haig (19♂ 5♀ FISH, 2♂ 1♀ TAM)   ; Morgan Gulch , 1 mi E Hayfork [40.543 -123.148], 22.v.1973, J. Powell (1♂ 1♀ EMEC, 1♂ 1♀ RBCM) GoogleMaps   ; Ruth Dam , 6.5 mi NW [40.439 -123.528], 7.iv.1966, G.R. Noonan (2♂ 2♀ FISH, 1♂ 1♀ LACM, LACM ENT 334035 View Materials , LACM ENT 334037 View Materials ) GoogleMaps   ; Yolo Co., Cache Creek Canyon, 7.iv.1956, P.M. Marsh (1♀ CAS)   , 26.iii.1966, E.A. Kane (1♀ FISH)   ; Davis [38.518 -121.770], 15.iv.1973, Y.B. Ibrahim (1♂ BEZA) GoogleMaps   ; Putah Creek Canyon [38.514 -122.072], 13.iv.1930, R.M. Bohart (1♀ FSCA) GoogleMaps   ; Rumsey [38.889 -122.236], 31.iii.1956, E.A. Kurtz (1♂ FISH) GoogleMaps   , 7.iv.1956, E.I. Schlinger (1♂ 1♀ CAS)   , R.C. Bechtel (1♀ CAS, 1♂ LACM, LACM ENT 334019 View Materials ), R.M. Bohart (1♀ FISH)   , 21.iv.1956, E.A. Kurtz (1♂ FISH)   , 21.iv.1973, Y.B. Ibrahim (1♂ 1♀ BEZA)   ; Rumsey , 2 mi N [38.911 -122.265], 12.iv.1975, R.W. Thorp (1♂ BEZA) GoogleMaps   .

Other Material Examined (3 specimens). U.S.A.: CALIFORNIA: Sonoma Co., Healdsburg [38.623 - 122.837], 7.v.1974, G. Pereira (1♂ RBCM) GoogleMaps   ; Yolo Co., Putah Canyon [38.514 -122.072], 20.iii.1960, M.E. Irwin (1♀ BEZA) GoogleMaps   ; Rumsey [38.889 -122.236], 28.iv.1957, J.E. Bath (1♀ BEZA) GoogleMaps   .

Taxonomic Notes. Specimens have been previously identified as L. drabicolum   or L. californicus   .

Etymology. Named after the biblical figure Esau, who was described as a “hairy man” (Genesis 27:11) and a “cunning hunter” (Gen 25:27) in the King James Version; the name is indeclinable in Latin. The dense, strong macrosetae on the male genitalia are a distinctive character for this species of predator.

Distribution ( Fig. 37 View FIGURES 37–40 ) Nearctic; USA, northwestern California. Type locality: U.S.A., California, Trinity Co., Junction City.

Phylogenetic Relationships. Member of the bivittatus   section, drabicolum   group.

Natural History. Habitat: river banks in mid-elevation mountains. Found perching on river sandbars near the forest’s edge, sometimes concurrently with L. zonatus   ( Fig. 18 View FIGURES 14–21 ). Known flight dates range from 29 March to 7 June, most in April and May.


Smithsonian Institution, National Museum of Natural History


Oregon State University


Royal British Columbia Museum


Monte L. Bean Life Science Museum


Estonian Museum of Natural History


University of Michigan, Museum of Zoology


Essig Museum of Entomology


Canadian National Collection of Insects, Arachnids, and Nematodes


University of Wyoming Insect Museum and Gallery


California Academy of Sciences


Natural History Museum of Los Angeles County


Florida State Collection of Arthropods, The Museum of Entomology