Austrothaumalea spatulata Schmid, 1970

Pivar, Robert J., Sinclair, Bradley J. & Moulton, John K., 2020, Revision of the South American species of Austrothaumalea Tonnoir (Diptera Thaumaleidae), Zootaxa 4853 (4), pp. 509-526 : 520-522

Austrothaumalea spatulata Schmid

( Figs 2 , 3B , 4E , 5E , 6D , 7D , 8 , 9C,D )

Austrothaumalea spatulata Schmid, 1970: 501 .

Other references: Arnaud, 1977: 284 (distribution); Cooper, 1991: 79 (CNC type catalogue); Sinclair, 1992: 492 (male terminalia studied); Theischinger, 1986: 316 (phylogenetic discussion).

Austrothaumalea spatula Schmid : Sinclair 2008b: 12 (lapsis calami, fusca species group).

Type material examined. Holotype: ♂, minuten pinned, with abdomen mounted in resin below specimen, labelled: “ Estero la Jaula / Curico, CHILE / I.1964, L. Pena / Nothofagus”; “ HOLOTYPE / CNCNo. 11,305/ Thaumalea spatulata Schm. [red label]”; “ CNC/ 803775 ” [genitalia dissected, slide mounted below] ( CNC) . Allotype: ♀, same label data as holotype, except, CNC 803775 ( CNC) . Paratypes: CHILE: Region VI (O’Higgins) : Bosque de los Conservadores Graneros, 1–4-III-62, 1100 m, Pena, CNC #11.035 (1♂, 1♀, CNC) .

Recognition. The quadrate apex of its parameres and the quadrate posterior margin of the gonocoxal plate are key characteristics for recognizing this species. It lacks the posterior epandrial projections found in A. apicalis .

Redescription. Male. n = 8. Length 1.8–2.2 mm. Colouration ( Fig. 3B ). Head dull, dark brown; pronotum, postpronotum, postpronotal lobe and lateral margins of prescutum brown; prescutum and mesoscutum shiny, primarily yellow, with pleura and posterior margin of mesoscutum brown with posterior brown rectangle, anterior corners of rectangle extended into two longitudinal brown vittae connecting, or nearly so, to posterior vittae extending from hind margins or prescutal dark patches; scutellum shiny, dorsal aspect brown with lateral yellowish brown patches, ventral aspect yellow; mediotergite shiny, brown; katepisternum yellow near coxa then turning brown, remaining pteropleuron yellowish brown to brown; posterior basalare yellowish brown; halter brown; legs pale brown, tarsi darker; abdomen dark brown, hind margins of tergites whitish; terminalia dark brown, gonostyli light brown.

Head. Eyes above antennae broadly joined, barely exposing frons above antennae. Flagellomeres 1–3 expanded, subquadrate; 1 as long as 2 and 3 combined; flagellomeres 4–10 thin, cylindrical, becoming progressively more elongate. Vertex clothed in golden setae of uniform length, with sparse long, black orbital setae.

Thorax. Pronotal setae longer than scutal setae. Scutum clothed dorsally in short, golden setulae; notopleural, supra-alar and postsutural setae long, black. Pteropleuron bare. Fore- and mid legs with tarsi simple, hind leg with tarsomere 4 bilobed.

Wing ( Fig. 2 ). Wing length: 2.8–3.3 mm. Lightly infuscate throughout, slightly darker where R 4+5 meets apex; apex rounded; C and posterior wing margin with fringe of microtrichia; Sc incomplete; R 1 and R 1 (+R 2+3) without weakenings or depigmented gaps; R 1 (+R 2+3) with uniseriate row of microtrichia along entire length, remaining veins bare; R flexed into cell br; R 2+3 crossvein very weak or absent, at most a faint infuscation, situated slightly beyond midpoint of R 1 (+R 2+3); bend in R 4+5 well-defined; R 4+5 and M 1 running parallel toward margin; M 1 and M 2 straight; M 4 slightly sinuous; CuA with basal spur shorter than crossvein m-cu, may be distinct or indistinct.

Abdomen. Abdominal sternite 1 narrow, spectacle-shaped; sternite 2 with slender median sclerite and lightly sclerotized posterior rectangle, a few setae on posterior margin; sternites 3–7 rectangular, weakly sclerotized, setae restricted to posterior half and laterad; anterior margin of sternites 5–7 thin, well sclerotized; sternite 8 crescentshaped, bare, anterior margin well-sclerotized, arched slightly into preceding sternite.

Terminalia ( Figs 4E , 5E ). Epandrium trapezoidal from ventral aspect; apical third slightly tapered; posterior margin broad and rounded; lacking pointed posterolateral processes. Hypandrium broad in ventral view, nearly subequal to basal width of gonostylus; anterior margin slightly concave. Gonocoxite broadest medially, tapered toward apex. Gonostylus about two-thirds length of gonocoxite, curved gently throughout; broadest basally, gradually tapered with small tooth at apex. Parameres distally fused, slightly more than half-length of epandrium, spatula-like, broadest apically. Gonocoxal plate rectangular, short, about half-length of gonocoxite; broad basally; apical margin truncate; basally not fused to hypandrium. Cercus weakly sclerotized, situated medially.

Female. n = 2. Similar to male except as follows: Length: 2.5–2.7 mm. Abdomen: Tergites 7–9 noticeably more sclerotized than preceding tergites; only anterior margin of sternite 7 well-sclerotized. Terminalia ( Figs 6D , 7D ): Hypogynial valve projected slightly beyond tergite 9; posterior margin with rounded cleft in ventral view, forming two truncate lobes; densely setose. Tergite 9 subquadrate in lateral view, wider than tergite 8, without lateral projections. Sternite 9 (genital fork) slender, weakly sclerotized, with two rod-shaped sclerites anteriorly and two triangular sclerites next to hypogynial valve; lateral arms extended past hypogynial valve, arms closely approximated along midline, thin anteriorly, distal half expanded. Hypoproct thin, divided into pair of sclerites. Cercus rounded, projected posteriorly; bearing numerous setae. Spermathecal ducts not observed.

Immature Stages. Unknown.

Additional Material Examined. CHILE: Region VI (O’Higgins): Rte. I-45, 16-XII-2016, 34°46′29.2″S 70°40′03.9″W, elev. 827 m, stream, J.K. Moulton & R. J. Pivar (1♂) ; Region VII (Maule): Los Queñes , Rte. J-25, 6-XII-2016, 34°59′48.8″S 70°48′37.0″W, elev. 684 m, seep, J.K. Moulton & R. J. Pivar (4♂, 1♀ *) ; Region VIII ( Bío Bío ): Rte. Q-689, 8-XII-2016, 37°54′55.6″S 71°35′43.2″W, elev. 552 m, cascading creek, J.K. Moulton & R. J. Pivar (1♂, 1♀ *) .

Distribution. Known from the Andes of central Chile ( Figs 8 , 9C,D ).

Remarks. The O’Higgins specimen collected by the authors differs somewhat in appearance from the other specimens in that the posterior margin of the epandrium is slightly concave. Molecular fingerprinting matches that of other A. spatulata specimens. This is the northern-most locality for this species and likely indicates population variation.

Figures

FIGURE 2. Left wing of Austrothaumalea spatulata. Abbreviations: C, costa, CuA sp, anterior branch of cubital vein and spur; M, medial veins; m-cu, medial-cubital crossvein; R, radial veins; r-m, radial-medial crossvein; Sc, subcosta. Scale bar = 1.0 mm.

FIGURE 3. Adult habitus photographs of Austrothaumalea, lateral view. A, A. apicalis (♂); B, A. spatulata (♂); C, A. chilensis (♂); D, A. fredericki sp. nov. (♂); E, A. setipennis stat. rev. (♀). R2+3, second + third radial vein. Scale bars = 1.0 mm.

FIGURE 4. Ventral views of male Austrothaumalea terminalia. A, A. apicalis; B, A. chilensis; C, A. fredericki sp.nov.; D, A. setipennis stat. rev.; E, A. spatulata. Abbreviations: c, cercus; gcx, gonocoxite; gcxP, gonocoxal plate; gst, gonostylus; hypd, hypandrium; pm, paramere.Arrow denotes apical epandrial projection. Scale bars = 0.1 mm.

FIGURE 5. Lateral views of male Austrothaumalea terminalia. A, A. apicalis; B, A. chilensis; C, A. fredericki sp. nov.; D, A. setipennis stat. rev.; E, A. spatulata. Abbreviations: c, cercus; epand, epandrium; gcx, gonocoxite; gcxP, gonocoxal plate; gst, gonostylus; hypd, hypandrium; pm, paramere. Arrow denotes apical epandrial projection. Scale bars = 0.1 mm.

FIGURE 6. Ventral views of female Austrothaumalea terminalia. A, A. apicalis; B, A. chilensis; C, A. setipennis stat. rev.; D, A. spatulata. Abbreviations: c, cercus; gen fk, genital fork; hypct, hypoproct; hyp vlv, hypogynial valve; lat arm, lateral arms; spthc, spermatheca.. Scale bars = 0.1 mm.

FIGURE 7. Lateral views of female Austrothaumalea terminalia. A, A. apicalis; B, A. chilensis; C, A. setipennis stat. rev.; D, A. spatulata. Abbreviations: c, cercus; gen fk, genital fork; hypct, hypoproct; hyp vlv, hypogynial valve; lat arm, lateral arm; spthc p, spermathecal pump. Scale bars = 0.1 mm.

FIGURE 8. Known distribution of South American Austrothaumalea.

FIGURE 9. Examples of Austrothaumalea habitats in Chile. A, rock face seep where A. chilensis and A. setipennis stat. rev. were collected (38°13′20.3″S 71°44′41.1″W); B, collection site of A. fredericki sp.nov. (41°08.47′S 72°35.28′W); C, collection site of A. spatulata (34°59′48.8″S 70°48′37.0″W); D, northernmost collection site of A. spatulata in the Chilean Matorral, inset showing small trickle of water where specimen was collected (34°46′29.2″S 70°40′03.9″W).