Lasiopogon ripicola Melander

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 : 74-76

Lasiopogon ripicola Melander

Lasiopogon ripicola Melander, 1923: 143 .

Diagnosis. ( Fig. 33 ) A medium-large grey species from rivers of the Columbia River basin of Washington and Idaho; setae mostly black, except mystax variable from white to black, short notal setae white, fine setae on femur white; scutum tomentum greyish, with brown dorsocentral stripes; tergites with basal brown tomentum in lateral spots; apical 40–50% covered in grey tomentum. Epandrial halves slender, moderately curved in dorsal view; phallus dorsal carina protruding far past gonopore, with apex swollen and pointed inward to form an imaginary right angle with the aedeagal tube. Ovipositor dark brown/black, acanthophorite spines black.

Redescription. Body length ♂ 11.1–12.3mm; ♀ 11.2–12.3mm. Head. HW ♂ 2.37–2.67mm; ♀ 2.56–2.68mm. FW ♂ 0.53–0.62mm; ♀ 0.57–0.65mm. VW ♂ 0.95–1.10mm; ♀ 1.02–1.13mm. VW/HW = ♂ 0.39–0.43; ♀ 0.39– 0.42. FW/VW = ♂ 0.53–0.56; ♀ 0.53–0.58. VD/VW = ♂ 0.14–0.17; ♀ 0.17–0.21. GH/GL = ♂ 0.37–0.46; ♀ 0.39–0.54. Face yellow-grey, vertex brown to grey. Ventral setae (beard, labium, palps) white; mystax varies from completely yellowish-white to completely black, or mixed; setae of vertex and occiput black. Occipital macrosetae relatively straight, longest to 0.8mm, curved anterolaterally posterior to frons; lateral macrosetae short. Frontal setae reach apex of pedicel; orbital setae curved over eye margin; ocellar setae indistinct amidst frontal setae. Antennae. Black with thin grey tomentum, stylus slightly reddish-black. Setae mostly black, a few short white setae on scape, 1 short seta on postpedicel. Postpedicel moderately long, dorsal and ventral margins slightly bowed in near base; stylus moderately long. WPP/LPP = ♂ 0.25–0.28; ♀ 0.23–0.32. LAS/LPP ♂ 0.64–0.74; ♀ 0.55–0.72. Thorax. Prothorax grey, with white setae; postpronotal lobes brown, the lateral angle chestnut, setae mixed white and black. Scutum tomentum grey to greyish-brown; dorsocentral stripes brown; acrostichal stripes dark grey. Acrostichal and anterior notal setae usually white, rarely black, shorter or equal in length to scape, other notal setae black. Dorsocentral setae black, anteriors 3–5 (to 1.0mm), posteriors 4–5; postalars 2–3; supra-alars 1–4; presuturals 2–3; posthumerals 1.Scutellar tomentum grey to greyish-brown; rim inflated, leaving a semi-circular line impressed inside the dorsal edge; apical macrosetae black, abundant (6–13 on each half); short vertical setae on uppermost edge of rim white. Pleural tomentum dorsally brownish grey, ventrally grey. Katatergite setae mostly black (3–10), with 1–5 white macrosetae; katepisternal setae long, white; anepisternal setae 4–6, black (to 0.7mm), many short black setae along dorsal margin and several long white setae in posteroventral corner; anepimeron with 0–1 fine setae.

Legs. Base color dark brown/black, covered in thin grey tomentum; bare at joints. No coxal peg. Coxae with long white setae; main macrosetae of legs black, fine setae white except on tarsi 3–5. Ventral setae on femur as long or slightly longer than femur width; dorsoapical macrosetae on profemur fine, indistinguishable from the surrounding setae, 3–6; macrosetae on other femorae strong, short, mesofemur with 3–9, metafemur with 9–17. Protibia with ventral macrosetae about 2 times longer than tibial width; dense apicoventral patch of short setae on protibia yellow, no patch on metatibia. Claws chestnut over basal 70%, black apically. Wings. Veins dark brown; membrane hyaline. DCI = 0.27–0.39. Halter knob cream, without spot, stem dark brown. Abdomen. Male. Tergite cuticle dark brown/black; thin brown tomentum on tergite bases, grey tomentum covers apical 40–50% of each tergite (80% of tergite 1) and extends anteriorly broadly on lateral margins and along midline to divide the brown into two lateral spots. Tergite 1 with 3–7 black and 1–4 gold lateral macrosetae; lateral setae white, long (on tergite 1–3 as long as halter, on tergites 4–7 as long as scape + pedicel); dorsal setulae short, white. Sternite tomentum grey, setae white. Female. As in male, except lateral setae of all tergites no longer than scape + pedicel, dorsal setulae black, lateral setae on tergites 5–7 rarely black. Male genitalia. Cuticle dark brown/black, with thin grey tomentum; setal brush dark brown, other setae dark brown/black on hypandrium/gonocoxite complex and ventrolaterally on epandrium, white dorsomedially on epandrium and on cerci. Epandrium elongate, in lateral view the width about 42% the length, widest in basal third; apex rounded with ventral tooth. In dorsal view, medial margins of epandrium moderately curved at 32% from base, relatively straight apically, outer margins suddenly tapered at apex; basal sclerite present. Phallus paramere sheath dorsally about 40% the length of phallus; paramere sheath without ventral ornamentation; dorsal carina protruding far past gonopore, with apex swollen but slightly dorsoventrally flattened and pointed inward to form an imaginary right angle with the aedeagal tube. Ejaculatory apodeme in lateral view moderately bent dorsally, with broad dorsal carina along entire length. Subepandrial sclerite with triangular central unsclerotized area in basal 30% narrowing to a parallel-sided gap in central portion; spines parallel-sided, blunt, distributed relatively evenly.

Female genitalia. Undissected: Cuticle dark brown/black, with sparse fine white setae; macrosetae on lateral lobes white; hypogynial valves long, mostly bare; cerci brown with pale setae (rarely dark brown); acanthophorite spines black.

Variation. Mystax color is variable in this species and unreliable as a taxonomic character. Specimens from the core of the range (around Pasco, WA) have primarily white mystaces, whereas flies from the periphery (e.g., the eastern slopes of the Cascades, the Dalles, or southwestern Idaho) have primarily black mystaces. At the Snake River near the Washington-Idaho border we have caught flies of all three phenotypes (white/black/mixed) on the same beach with no discernible differences in genitalia morphology or genetic haplotypes.

Type Material. HOLOTYPE (examined) ♂ labelled: “[rectangular beige label] Wawawai/ Wash”; “[rectangular red label] TYPE/ Lasiopogon / ripicola/ Melander”; “[rectangular white and green label] ALMelander/ Collection/ 1961”; “[rectangular beige label] Lasiopogon / ripicola/ Mel.”; “[rectangular white label] USNMENT00972436”. USNM.

PARATYPES (16 specimens examined): U.S.A.: WASHINGTON: Lincoln Co., Wilbur [47.757 -118.705] , 5.v.1911, A.L. Melander (1♀ USNM, USNMENT1100266 ) ; Whitman Co., Wawawai [46.581 -117.297], A.L. Melander (1♂ 1♀ USNM, USNMENT1100252 – USNMENT1100253 ) , 17.iv.1908, A.L. Melander (1♂ USNM, USNMENT1100263 ) , 23.iv.1909, A.L. Melander (1♀ USNM, USNMENT1100255 ) , 24.iv.1909, A.L. Melander (1♀ CNC, CNC 335 , 4♂ 2♀ 1? USNM, USNMENT1100256 – USNMENT1100262 ) , 20.v.1911, A.L. Melander (1♀ USNM, USNMENT01100254 [allotype]) ; Yakima Co., N Yakima , 8.v.1903, E. Jenne (1♂ USNM, USNMENT1100265) , 19.v.1903, E. Jenne (1♀ USNM, USNMENT1100264 ) .

Other Material Examined (263 specimens). U.S.A.: IDAHO: Ada Co., Boise, Barber Park , 43.56977 - 116.13908, 14.iv.1990, G. Stephens (2♂ 1♀ [1 pr in cop] ESUW) , 22.iv.1990, G. Stephens (1♂ RBCM) , 17.iv.2014, T.A. McKnight (1♂ 1♀ [2 EtOH] UMMZ) ; Boise Co., Horseshoe Bend [43.904 -116.197], 18.v.1933, F.H. Shirck (1♂ 1♀ CAS, 1♂ RBCM) ; Horseshoe Bend, Payette River sandbank, 43.90385 -116.19717, 18.iv.2014, T.A. McKnight (4♂ 2♀ [2 pr in cop] RBCM, 7♂ 4♀ [3 pr in cop] TAM, 6♂ 1♀ [3 EtOH, 1 pr in cop] UMMZ) ; Canyon Co., Boise River @ Ft Boise Wildlife Area , 3 mi W of Parma, 43.80222 -117.00055, 23.iv.2014, T.A. McKnight (2♂ 1♀ [1 pr in cop] RBCM, 1♂ 2♀ [1 pr in cop] TAM, 1♂ UMMZ) ; Boise River jct Hwy 95, 4 mi SE of Parma, 43.74877 -116.91538 ; 18.iv.2014, T.A. McKnight (2♂ 2♀ [1 pr in cop] RBCM, 2♂ 1♀ [1 pr in cop] TAM, 4♂ 1♀ [2 EtOH, 1 pr in cop] UMMZ) ; Parma [43.802 -117.001], 13.v.1933, F.H. Shirck (1♂ CAS) , 18.v.1933, F.H. Shirck (1♂ CAS) ; Latah Co., Viola [46.838 -117.026], 27.v.1962, B.F. Finnigan (1♀ WSUC) ; Nez Perce Co., Lewiston [46.451 - 116.819], J.M. Aldrich (2♂ EMEC) , 12.v.1901, J.M. Aldrich (1♂ CAS) , 3.v.1904, J.M. Aldrich (1♂ 1♀ EMEC) , 26.iv.1912, J.M. Aldrich (2♀ EMEC, 1♂ RBCM) ; Lewiston , 10 mi E [46.388 -116.794], 16.iv.1981, J.B. Johnson (1♀ BEZA) ; Lewiston , 3 mi S [46.361 -117.060], 5.v.1970, W.F. Barr (1♂ 3♀ ESUW, 1♂ 1♀ RBCM) ; Spalding [46.451 -116.814], 24.iv.1949, M.T. James (1♂ WSUC) ; OREGON: Hood River Co., Hood River [45.713 -121.516], 15.v.1917, F.R. Cole (3♂ FISH) , 22.v.1917, F.R. Cole (1♂ FISH) , 12.vi.1917, F.R. Cole (1♂ FISH) , 22.vi.1917, F.R. Cole (1♂ FISH) , 24.vi.1917, F.R. Cole (1♂ FISH) ; Wasco Co., The Dalles [45.604 -121.191], 2.v.1927, H.A. Scullen (1♀ CAS) ; WASHINGTON: Asotin Co., Snake River, opposite Clarkston [46.431 -117.040], 3.v.1925, A.L. Melander (3♂ USNM, USNMENT1100819 , USNMENT1100829 , USNMENT1100832 ) ; Snake River, sandy bank 1.6 mi S of Asotin, jct Hwy 129, 46.33185 -117.02672, 21.iv.2014, T.A. McKnight (1♂ 1♀ RBCM, 2♂ 1♀ TAM, 2♂ [2 EtOH] UMMZ) ; Snake River, sandy bank 4 mi S of Asotin jct Hwy 129, 46.30365 -117.00379, 21.iv.2014, T.A. McKnight (1♂ 1♀ [1 pr in cop] RBCM, 2♂ 2♀ [1 pr in cop] TAM, 1♂ 1♀ [1 EtOH] UMMZ) ; Benton Co., Benton City [46.254 -119.474], 6.v.1966, C.W. Sabrosky (1♂ USNM, USNMENT1100817 ) ; Hanford Works , wash @640’, sagebrush [46.4591 -119.542], 29.iv.1952, R.H. Whittaker (1♀ WSUC) ; Chelan Co., Cashmere [47.5254 -120.472], 12.v.1935, C.W. Getzendaner (2♂ 1♀ CAS) ; Franklin Co., Pasco [46.206 -119.037], 23.iv.1933, I. Wilcox (14♂ 5♀ 1? CAS, 2♂ 1♀ FISH, 1♂ 1♀ RBCM, 3♂ USNM, USNMENT1100269 – USNMENT1100270 , USNMENT1100273 ), J. Wilcox (1♂ 1♀ BEZA, 37♂ 14♀ 3? CAS, 1♀ CNC, 2♂ 1♀ EMEC, 3♂ 2♀ FISH, 1♂ 1♀ LACM, LACM ENT 334053 – LACM ENT 334054 , 4♂ 4♀ MCZ, 4♂ 4♀ OSUC, OSUC 194393 – OSUC 194400 , 4♂ 1♀ RBCM, RBCM ENT 991-86346 , 1♂ 1♀ UCRC, 3♂ 4♀ USNM, USNMENT1100271 – USNMENT1100272 , USNMENT1100274 – USNMENT1100278 ), 17.iv.1934, C.H. Martin (1♂ ESUW, 1♀ FISH, 3♂ 3♀ FSCA), D. Martin (1♂ FISH, 2♂ FSCA, 1♂ RBCM) ; Garfield Co., Wawawai , 14 mi S [46.427 -117.324], 9.v.1958, D.W. Tuff (1♀ WSUC) ; Okanogan Co., Chewuch River , N of Eight Mile Creek [48.609 -120.163], 23.v.1991, S.G. Cannings (6♂ 4♀ [3 pr in cop] RBCM, RBCM ENT 991-60112 , RBCM ENT 991-60118 – RBCM ENT 991-60121 , RBCM ENT 991-68111 , RBCM ENT 991-68114 – RBCM ENT 991-68117 ) ; Whitman Co., Pullman [46.737 - 117.190], 4.iv.1909, A.L. Melander (1♀ USNM, USNMENT1100267 ), 24.iv.1909, A.L. Melander (1? USNM, USNMENT1100268) ; Wawawai [46.581 -117.297], 24.iv.1909, W.M. Mann (1♂ MCZ) , 1.v.1909, W.W. Mann (1♀ MCZ, 1♀ USNM, USNMENT1099796 ), 30.iv.1961, M.T. James (1♂ 1♀ RBCM, 3♂ 2♀ WSUC), 4.[date illegible] (1♀ EMEC) .

Taxonomic Notes. The original description lists a male and female specimen as “types”, i.e., syntypes and not holotype / allotype. However, for decades the male specimen has been isolated, labeled, and treated as a standalone “type” while the female was labeled and treated as an allotype among the paratypes. Males are the preferred sex for resolving taxonomic questions in this genus, and so we do not see ambiguity in this species that would precipitate designating a lectotype.

The two specimens from Pullman (Whitman Co., Washington) bear the same paratype labels as the other paratypes and help the series of specimens with paratype labels add up to the total noted in the original description; however, this locality was not mentioned in the original text and so we have not included them in the official paratype list .

Because L. ripicola was originally thought to only have a white mystax, black-mystaced specimens were frequently misidentified as L. willametti . The two species are mostly allopatric, but there is a small area of overlap in Boise, Idaho, and we believe further work should investigate whether hybridization occurs between these two species, as well as with L. puyallupi .

Etymology. No explanation given in the original description, but evidently from the Latin ripa = bank, cola = inhabitant of; like many Lasiopogon species, this one lives on the banks of rivers.

Distribution ( Fig. 39 ) Nearctic; USA, eastern Washington, western Idaho, and northeastern Oregon. A specimen with a locality label of “Alberta” has been referenced as this species in the literature ( Adisoemarto 1967) and would be a far outlier, but the voucher specimen is no longer confidently identifiable due to dermestid damage. Type locality: U.S.A., Washington, Wawawai.

Phylogenetic Relationships. Member of the bivittatus section, basal to the rest of the actius group.

Natural History. Habitat: sandy riverbanks. Perches on bare sand adjacent to low, scraggly vegetation ( Fig. 14 ), rarely on boulders or cobble. Dates collected: April 4 to June 24, most in late April. Three males and three females (including a female in a mating pair) with prey: three Muscidae (Diptera) , one Sarcophagidae (Diptera) , one Hydroptilidae (Trichoptera) , and one Brachycentridae (Trichoptera) .

Figures

FIGURE 33. 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. (33) L. actius, L. dimicki, L. puyallupi stat. 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).