Lasiopogon albidus Cole & Wilcox

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 : 34-35

Lasiopogon albidus Cole & Wilcox

Lasiopogon albidus Cole & Wilcox, 1938: 21 .

Diagnosis. ( Fig. 31 ) A medium-sized pale grey species from inland sand dunes of Oregon and Washington; all setae white to golden; macrosetae well developed; trochanters and femur/tibia joint ferruginous; tergites with faint basal spots of brown tomentum, otherwise covered in thick silvery-grey tomentum. Epandrial halves strongly concave medially, with long setae; ovipositor dark brown with yellow acanthophorite spines.

Redescription. Body length ♂ 8.4–11.2mm; ♀ 9.5–11.9mm. Head. HW ♂ 1.84–2.28mm; ♀ 1.95–2.44mm. FW ♂ 0.43–0.57mm; ♀ 0.46–0.62mm. VW ♂ 0.87–1.03mm; ♀ 0.94–1.04mm. VW/HW = ♂ 0.45–0.47; ♀ 0.43– 0.48. FW/VW = ♂ 0.49–0.55; ♀ 0.49–0.60. VD/VW = ♂ 0.07–0.11; ♀ 0.10–0.13. GH/GL = ♂ 0.54–0.57; ♀ 0.38–0.44. Face with silver-grey tomentum; vertex with gold-grey tomentum. Mystax, frontal, and occipital setae straw-colored; beard and labial setae usually white. Occipital macrosetae relatively straight and of average length, those behind the dorsomedial angle of the eye 0.6mm long and most curved; lateral and ventral macrosetae shorter, straighter. Frontal setae fine and short; orbital setae long, erect. Antennae. Dark brown, postpedicel black/brown. Setae straw-colored, no setae on postpedicel. Postpedicel rectangular, slightly tapered in apical half; stylus of even width, tapered only at apex. WPP/LPP = ♂ 0.31–0.35; ♀ 0.30–0.33. LAS/LPP = ♂ 0.57–0.65; ♀ 0.57–0.69. Thorax. Prothorax grey/brown, setae white; postpronotal lobes grey to brownish grey, lateral angle ferruginous, setae white. Scutum tomentum pale grey, brown around the perimeter. Dorsocentral stripes pale gold-brown with dark cuticle subshining; acrostichal stripes absent. Macrosetae straw-colored, shorter setae white. Anterior dorsocentral macrosetae 5–6 (to 0.9mm), mixed with finer setae; 4 posteriors. Postalars 4, with about 7 shorter setae; supra-alars 3 with 3 shorter setae; presuturals 3–4; posthumerals 1–2. Scutellar tomentum grey; rim strongly inflated, leaving a semi-circular line impressed inside the dorsal edge; apical macrosetae straw-colored, abundant (usually 8–10+ on each side) and mixed with many other long setae. Pleural tomentum gold. Katatergite macrosetae straw-colored, 8, with a few weaker setae; katepisternal setae sparse, moderately long, white; anepisternal setae 4–5, moderately strong (to 0.8mm) and mixed with other setae, a patch of short white setae on dorsal margin of sclerite; anepimeron with a single fine seta, white.

Legs. Cuticle dark brown to black, trochanter and base of femur ferruginous, sometimes reddish at joints of femur/tibiae and tarsal bases; tomentum sparse, grey. No coxal peg. Macrosetae on legs dirty white, finer setae white. Ventral setae on femur somewhat sparse and short, as long as or shorter than width of femur; dorsolateral macrosetae on femur strong, 7–8 on profemur, mixed with many finer setae; 4–5 on mesofemur; longer and more numerous on metafemur (15–16). Protibia with longest macrosetae about 3–4 times longer than tibial width. Claws chestnut over basal 40–50%, black apically. Wings. Veins brown, paler in apical half; membrane transparent, milky white when viewed obliquely. DCI = 0.33–0.49. Halter yellow, with no spot. Abdomen. Cuticle dark brown/black basally, covered in grey tomentum except for very faint and broadly separated patches of brown tomentum at bases of tergites 2–7, apical light grey tomentum covers about 50% the length of each tergite and extends medially and laterally to the tergite base; tergite 1 completely covered in light grey tomentum. All tergites in male with long lateral setae; tergites 4–7 in female with short lateral setae, anterior tergites as in male. Lateral macrosetae on first tergite long but relatively weak, 8–9. Sternite tomentum grey, setae straw-colored/white. Male genitalia. Epandrium and hypandrium/gonocoxite complex cuticle brown/chestnut; covered in thin grey tomentum and long white setae, setal brush yellowish white, dense. Epandrium elongate, in lateral view the width about 45% the length, widest in basal third, dorsally and ventrally sinuate; apex right-angled ventrally, straight-edged apically, and rounded dorsally. In dorsal view, medial margins of epandrium moderately curved, curvature starts around 35% from base; basal sclerite prominent. Phallus paramere sheath dorsally 45% the length of phallus; paramere sheath with a strong subapical ventral tooth; dorsal carina jutting out like a thin fin near apex, leaving only a narrow gap between apex of dorsal carina and gonopore. Ejaculatory apodeme in lateral view moderately bent dorsally in basal quarter, strongly recurved at apex, dorsal carina narrowly filling the gap. Subepandrial sclerite with triangular central unsclerotized area in basal 50% narrowing to a parallel-sided gap in central portion; spines parallel-sided, blunt, densely arranged apically, sparse elsewhere.

Female genitalia. Undissected: Setae white, abundant, erect. Tergite 8 dark brown/black; sternite 8 dark brown, paler medially at bases of hypogynial valves; lateral lobe setae strong. Hypogynial valves with fine setae, concentrated basally and apically. Cerci brown/black with pale setae; acanthophorite spines yellow.

Type Material. HOLOTYPE (photos examined) ♂ labelled: “[rectangular white label] Kiona, Wn./ IV-23 1933 ”;”[rectangular white label] J. Wilcox/ Coll.”; “[rectangular salmon label] HOLOTYPE / Lasiopogon /albidus/ Cole & Wilcox”;”[rectangular white label] California Academy/ of Sciences, Type No. 6407”. CAS.

PARATYPES (56 specimens examined): U.S.A.: WASHINGTON: Benton Co., Kiona [46.2540 -119.2890], 23.iv.1933, Itol Wilcox (3♂ 3♀ CAS [allotype included], 1♂ CNC, CNC 16734, 1♀ EMEC, 2♂ 1♀ FISH, 1♀ UCRC, 2♂ 1♀ USNM, USNMENT1100141 – USNMENT1100143 ) , J. Wilcox (2♂ BEZA, 16♂ 4♀ 1? CAS, 1♀ CNC, CNC 16734, 1♂ EMEC, 1♀ FISH, 1♂ LACM, LACM ENT 334005 , 2♂ 2♀ MCZ, MCZ 19431, 2♂ 2♀ OSUC, OSUC 542538 – OSUC 542541 , 1♂ UCRC, 2♂ 3♀ USNM, USNMENT1100144 – USNMENT1100148 ) .

Other Material Examined (37 specimens). U.S.A.: OREGON: Harney Co., Alvord Basin T41S R35E S155E¼ [42.006 -118.594], 29.iv.1979, Cobb & Lightfoot (1♂ FISH) ; Lake Co., Alkali Lake, 2.5 km N on Hwy 395, 43.0217 -119.9896 °, 30.iv.2014, T.A. McKnight (1♀ [1 EtOH] UMMZ) ; Fossil Lake [43.353 -120.436], 16.v.1957, W.J. Hogg (2♂ 2♀ RBCM, RBCM ENT 991-69069 – RBCM ENT 991-69072 ) ; WASHINGTON: Benton Co., Hanford Site , sand dunes W of Columbia River, 46.5203 -119.3477, 25.iv.1995, R.S. Zack (1♂ 1♀ WSUC) ; Franklin Co., Juniper Dunes Wilderness , N entrance 18 mi NE of Pasco, 46.4249 -118.8301, 20.iv.2014, T.A. McKnight (3♂ 1♀ RBCM, 5♂ 2♀ TAM, 5♂ 2♀ [5 EtOH] UMMZ) ; juniper forest 30 mi NE Pasco [46.533 -118.584], 2.v.1970, E. Gage (1♀ BEZA) ; Walla Walla Co., Wallula 1 mi W [46.080 -118.908], 30.iv.1960, M.T. & H.B. James (2♀ RBCM, 2♂ 6♀ WSUC) .

Taxonomic Notes. Because of their similar pale appearance, specimens of L. quadrivittatus have occasionally been misidentified as this species, as in Nelson (1987).

Etymology. No explanation given in the original description, but evidently from the Latin albus = white; referring to the overall pale coloration of the body tomentum and setae.

Distribution ( Fig. 37 ) Nearctic; USA, inland sagebrush dunes of eastern Oregon and Washington; reports from Utah and Arizona are likely erroneous. All specimens that we have found identified as L. albidus from Utah and Arizona have proven to instead be L. quadrivittatus , and while we have not personally inspected every specimen listed as L. albidus in Nelson’s (1987) checklist of Utah asilids, the remaining records match entries for L. quadrivittatus in Cannings (2002) . Type locality: U.S.A.: Washington: Benton Co., 8 mi E of Kiona ( Cole and Wilcox 1938).

Phylogenetic Relationships. Member of the bivittatus section, likely basal to the drabicolum group.

Natural History. Habitat: inland sand dunes and sagebrush steppe. Found perching on bare sand dunes far from water with sparse grasses, sagebrush, and juniper ( Fig. 17 ) and “far from the dunes on a loamy-clay flatland interspersed by sandy patches […] vegetated largely by halophyte shrubs” ( Cobb et al. 1981: 10). Dates collected: April 20 to May 2 (an unverified report extends the range to May 16). Found in the same localities and habitats as L. chaetosus , but no specimen records coincide in phenology, suggesting that L. albidus may have an earlier emergence season. One male with prey: Cicadellidae (Hemiptera) nymph.

Figures

FIGURE 31. 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. (31) L. albidus, L. arenicola, L. asilomar sp. nov.

FIGURES 37–40. Distribution maps of georeferenced records for Lasiopogon species revised in this publication, part 1 of 2. Each map corresponds to one page of the morphology tabular key.

FIGURES 14–21. Representative habitats of inland sand-perching Lasiopogon species collected for this revision. (14) Washington: Asotin Co., Snake River, sandy bank 4 mi S of Asotin jct Hwy 129, 21.iv.2014 (L. ripicola). (15) Washington: Thurston Co., Tumwater, Deschutes River @ Pioneer Park, 15.v.2015 (L. puyallupi stat. nov.). (16) Oregon: Linn Co., Crabtree Creek @ Hwy 226 bridge 8 mi N of Lebanon, 19.v.2012 (L. willametti). (17) Washington: Franklin Co., Juniper Dunes Wilderness, N entrance, 18 mi NE of Pasco, 20.iv.2014 (L. albidus). (18) California: Marin Co., San Antonio Creek, San Antonio Rd 4.5 mi S of Petaluma, 15.iii.2014 (L. zonatus, L. esau sp. nov.). (19) California: Riverside Co., Little San Gorgonio Creek @ Potrero blvd bridge, 2 mi NW of Beaumont, 9.iii.2014 (L. wilcoxi sp. nov.). (20) New Mexico: Grant Co., Gila River below Forks campsite, 6.v.2015 (L. karli sp. nov.). (21) California: Riverside Co., Santa Ana River at Mt. Rubidoux, 4.iii.2013 (L. drabicolum).