Lasiopogon bitumineus McKnight, 2020

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 : 43-44

Lasiopogon bitumineus McKnight sp. nov.

urn:lsid:zoobank.org:act:ACF28276-167D-46C9-B0DF-887DDB779F86

Diagnosis. ( Fig. 35 ) A small to medium sized dark brown species with very long and robust black macrosetae on scutum and legs; both sexes with abdominal tergite tomentum in straight bands, brown basally and grey over apical 30–40% of each tergite. Male terminalia shining black, covered in long setae, epandrial halves narrow, strongly concave medially. Ovipositor black except for light tan apically and along midline of sternite 8, as well as hypogynial valves.

Description. Body length ♂ 6.8–7.4mm; ♀ 6.6– 7.6mm. Head. HW ♂ 1.59–1.76mm; ♀ 1.49–1.87mm. FW ♂ 0.38–0.43mm; ♀ 0.35–0.42mm. VW ♂ 0.73–0.76mm; ♀ 0.61–0.79mm. VW/HW = ♂ 0.43–0.46; ♀ 0.41–0.42. FW/VW = ♂ 0.52–0.57; ♀ 0.53–0.57. VD/VW = ♂ 0.09–0.10; ♀ 0.10–0.15. GH/GL = ♂ 0.38–0.49; ♀ 0.51–0.61. Face yellow-grey, vertex brown-grey. Ventral setae (on beard, labium, palps) white; mystax and all dorsal setae black. Occipital macrosetae fine, very long (to 0.7mm), especially posterior to frons, and strongly curved anterolaterally; lateral and ventral macrosetae reduced to short, fine, straight setae. Frontal setae very long, erect, densely abundant, longest reach apex of postpedicel; orbital setae also fine and long, gently curving over eye margin; ocellar setae also long, but fine and indistinct in ‘lawn’ of setae. Antennae. Black, with thin grey tomentum. Setae black, abundant; no setae on postpedicel. Postpedicel short, widest at midpoint; dorsal edge straight, ventral edge curved; stylus extremely long. WPP/LPP = ♂ 0.33–0.38; ♀ 0.39–0.40. LAS/LPP ♂ 0.87–0.93; ♀ 0.96–1.16. Thorax. Prothorax brown-grey, with yellowish-white setae; postpronotal lobes brown, the lateral angle dark chestnut, setae black-brown. Scutum tomentum brown, varying from greyish to copper or chocolate hued. Dorsocentral stripes dark brown; acrostichal stripes lighter but distinct. Notal and acrostichal setae black, widely spaced, long (up to 60% as long as dorsocentrals). Dorsocentral macrosetae black, extremely long (to 1.0mm), anteriors 4–7, posteriors 3–5. Postalars 2–3, with about 4 shorter setae; supra-alars 2–4 with a few short setae; presuturals 2–3; posthumerals 1. Scutellar tomentum grey-brown; rim inflated, leaving a semi-circular line impressed inside the dorsal edge; apical macrosetae black, abundant (4–10 on each half), mixed with other long setae. Setae on uppermost edge of rim short (30% as long as other macrosetae), point straight up. Pleural tomentum grey to brownish grey. Katatergite macrosetae black, long, 5–8, with a few fine short white setae; katepisternal setae fairly long, white; anepisternal setae 6–8, black (to 0.6mm), 0–5 short black setae along dorsal margin; anepimeron with 1–3 fine white setae. Legs. Base color dark brown/black, covered in thin grey tomentum; bare at femur-tibia joint and trochanters. No coxal peg. Coxae with long white setae. Main macrosetae of legs black, finer setae mostly white except some brown setae mixed in on femur apicoventrally and on protibia. Macrosetae on profemur fine, 10+, almost indistinguishable from the surrounding setae; apicolateral macrosetae on other femorae strong, short, mesofemur with 2–5, metafemur 6–10. Longest ventral setae longer than the width of the femur. Protibia with ventral macrosetae about 4 times longer than tibial width; dense patch of short yellow-brown macrosetae on inside of protibiae indistinct. Claws dark chestnut over basal 60%, black apically; pulvilli longer than claws. Wings. Veins dark brown; membrane hyaline but pale brown when viewed obliquely. DCI = 0.36–0.43. Halter knob cream, without spot, stem brown. Abdomen. Male. Tergite cuticle dark brown/black. Thin brown tomentum on tergite bases; bands of grey tomentum cover apical 40–50% of each tergite (segment 1 half to fully covered); ventrolaterally lighter grey-brown. Tergite 1 with 5–6 lateral black macrosetae. Lateral setae on tergites white, as long as scape + pedicel; dorsal setulae shorter, brown, straight. Sternite tomentum grey, setae white. Female. As in male, except basal brown tomentum thicker and covers more of each tergites, grey tomentum only over apical 20–60% of each tergite; lateral setae on tergite 3–7 black, shorter and sparser than in male. Male genitalia. Epandrium and hypandrium/gonocoxite complex cuticle shining dark brown/black, devoid of tomentum; with long, prominent dark brown/black setae, setal brush black. Epandrium long, slender, in lateral view the width 45% the length, widest in basal third, dorsal and ventral margins both constricted medially and flaring apically; apex gently concave with shallow subapical ventral tooth. In dorsal view, epandrial halves wide set, moderately concave; basal sclerite prominent. Phallus paramere sheath dorsally 48% the length of phallus; paramere sheath without ventral ornamentation; dorsal carina broad, coming to a slight point and then curving to rejoin paramere sheath apically. Ejaculatory apodeme in lateral view gently bent dorsally, with broad dorsal carina. Subepandrial sclerite U-shaped, with central unsclerotized area a tall bottle-shape over basal 70%; spines blunt, sparsely distributed.

Female genitalia. Undissected: Tergite 8 cuticle polished dark brown/black with black erect fine setae; sternite 8 dark brown basally, pale brown apically; hypogynial valves pale brown with a few fine setae; lateral lobe with fine black setae; cerci brown with pale setae; acanthophorite spines black.

Type Material. HOLOTYPE ♂ labelled: “[rectangular white label] USA: California: San Luis Obispo /Co., Oceano dunes @ Pismo State /beach, 1 km S of Oceano,/ Ericameria gully, N 35.08746° / W 120.61552°, elev: 12 m,/ 12 Mar 2014, TA McKnight #546.”. Our holotype label “ HOLOTYPE / Lasiopogon ♂ / bitumineus McKnight / des. T.A. McKnight 2017 [red, black-bordered label]” has been attached to this specimen. Deposited at USNM.

PARATYPES (74 specimens designated): U.S.A.: CALIFORNIA: San Luis Obispo Co., Dune Lakes , 3 mi S of Oceano [35.068 -120.615], 15.ii.1974, J. Doyen, J. Powell (4♂ 5♀ EMEC, 2♂ 1♀ RBCM), 20.iii.1974, J. Doyen, J. Powell (2♂ EMEC) , 23.ii.1975, J. Powell (1♂ BEZA, 6♂ 3♀ EMEC, 1♂ 1♀ RBCM), 24.ii.1975, J. Powell (1♂ EMEC, 1♂ RBCM), 4.iii.1977, J. Doyen (1♀ BEZA) ; Montaña de Oro State Park, dunes @ Sand Spit trailhead ( Ericameria zone), 35.30111 -120.87299, 12.iii.2014, T.A. McKnight (2♂ 2♀ [1 pr in cop] RBCM, 2♂ 3♀ [1 pr in cop] TAM, 2♂ [1 EtOH] UMMZ) ; Montaña de Oro State Park, dunes @ Sand Spit trailhead (iceplant zone), 35.30214 -120.87527, 12.iii.2014, T.A. McKnight (1♂ RBCM, 2♂ 2♀ [1 pr in cop] TAM) ; Morro Bay , 2.iii.1973, D.A. Thomas (2♂ 1♀ CAS) ; Oceano dunes @ Pismo State beach, 1 km S of Oceano, Ericameria gully, 35.08746 -120.61552, 12.iii.2014, T.A. McKnight (2♂ 2♀ [1 pr in cop] RBCM, 4♂ 1♀ [1 pr in cop] TAM, 4♂ [3 EtOH] UMMZ) ; Oso Flaco Lake , 5 mi S of Oceano [35.032 -120.627], 23.iv.1966, J. Powell (1♂ FISH) ; Oso Flaco State Park , coastal dunes, 35.01533 -120.61783, 3.iii.2007, M.E. Irwin (1♂ UAIC) , 13.iii.2007, M.E. Irwin (2♂ 4♀ UAIC) ; Santa Barbara Co., Vandenberg AFB, Coast road, back dunes, 34.641129 -120.617618, 14.ii.2016, A.J. Abela (3♂ UMMZ, 1♂ TAM) ; Vandenberg AFB, South Spur Road , 34.737300 -120.619964, 2.ii.2016, A.J. Abela (1♂ UMMZ) .

Taxonomic Notes. Specimens of this species have occasionally been misidentified as L. zonatus , L. gabrieli , and L. drabicolum .

Etymology. Latin for bitumen; adjective; refers to both the black color of this species in contrast to the sympatric pale L. littoris , as well as the type locality of Pismo, which is derived from “pismu” meaning tar or bitumen in the language of the indigenous Chumash people ( Klar 1975).

Distribution ( Fig. 41 ) Nearctic; coastal dunes in San Luis Obispo County, California. Type locality: U.S.A. California, San Luis Obispo Co., Pismo State Beach, 1 km S of Oceano.

Phylogenetic Relationships. Member of the bivittatus section but with uncertain placement, potentially sister to L. littoris or L. gabrieli .

Natural History. Habitat: Coastal dunes, especially backdune gullies perching in sandy patches near vegetation like mock heather ( Ericameria Nutt. ) and veldt grass ( Ehrharta calycina Sm. ), less often by iceplant ( Carpobrotus edulis (L.) N.E. Br.) ( Fig. 13 ). Flight dates for museum specimens range from 2 February–23 April; however, online photographs (see mating pair at https://bugguide.net/node/view/1187436) extend this range to 30 January. Field observations by the first author and A. Abela (pers. comm.) suggest that the flight period for this species begins and peaks a few weeks before the sympatric L. littoris emerges in abundance. Prey: one female pinned with Acreophthiria Evenhuis ( Diptera : Bombyliidae ). In addition, a live photograph (https://bugguide.net/node/view/1198571, see Fig. 1 ) shows a male with Tipuloidea ( Diptera ) prey.

Figures

FIGURE 1. Lasiopogon bitumineus sp. nov. male, feeding on prey (Diptera: Tipuloidea), at coastal sandy back dunes, Santa Barbara Co., California, U.S.A., 10.iii.2016. Photo by Alice Abela.

FIGURE 35. Matrix key of Lasiopogon morphology for species revised in this publication, indicating details of tergite tomentum, major setation, and dissected male genitalia. Taxa are grouped on pages with closely related and visually similar species. (35) L. bitumineus sp. nov., L. bivittatus, L. canningsi sp. nov., L. littoris, L. tumulicola sp. nov.

FIGURES 41–42. Distribution maps of georeferenced records for Lasiopogon species revised in this publication, part 2 of 2. Each map corresponds to one page of the morphology tabular key.

FIGURES 6–13. Representative habitats of coastal sand-perching Lasiopogon species collected for this revision. (6) Oregon: Lincoln Co., Gleneden Beach, NW tip of Salishan Spit, 17.v.2012 (L. actius on foredune, L. tumulicola sp. nov. in backdunes). (7) Washington: Grays Harbor Co., Westhaven State Park, dunes 2 mi NW of Westport, 20.vi.2013 (L. actius). (8) Oregon: Lincoln Co., Newport, Agate Beach State Park dunes, 21.vi.2013 (L. dimicki). (9) California: Humboldt Co., Clam Beach County Park ~5 mi SE of Trinidad, 15.v.2012 (L. canningsi sp. nov.). (10) California: San Mateo Co., Half Moon Bay State Beach, 5.vi.2013 (L. arenicola). (11) California: Monterey Co., Pacific Grove golf course, dunes in SW corner, 11.v.2012 (L. asilomar sp. nov.). (12) California: Santa Barbara Co., Rancho Guadalupe Dunes 1 mi S of parking lot, 9.v.2012 (L. littoris). (13) California: San Luis Obispo Co., Montaña de Oro State Park, dunes @ Sand Spit trailhead, 12.iii.2014 (L. bitumineus sp. nov., L. littoris weeks later).