Aspistomella Hendel, 1909

Genus Aspistomella Hendel, 1909 View in CoL

Aspistomella Hendel 1909b: 265 View in CoL .

Type species: Aspistomella lobioptera Hendel, 1909 , by original designation.

Aspistomella View in CoL : Hendel 1910: 10, 47; Steyskal 1968: 54.14.

Paraphyola Hendel 1909b: 261 View in CoL , syn. nov.

Type species: Paraphyola angustifrons Hendel, 1909 , by subsequent designation of Hendel (1910: 46).

Paraphyola View in CoL : Hendel 1910: 40, 46; Steyskal 1968: 54.20.

Diagnosis. This genus has all the diagnostic characters of the tribe Lipsanini : head and body with silver, greenish or cyan metallic sheen, sparsely whitish microtrichose, ocellar seta strong; phallus bare or covered with fine microtrichia, apically without glans; hypandrium symmetrical, with deep phallic guide, two areas of trichoid sensilla (corresponding to the pregonites and postgonites); female abdominal tergites 4–6 without anteromedial apodemes; only two spermathecae present.

Aspistomella species can be easily distinguished from other Lipsanini species by the combination of the following characters: epistome high, at least 2× higher than clypeus; frontal and interfrontal setae well differentiated, longer than fine and short parafrontal setulae; crossvein r-m distal to the apex of vein R 1 or at most very slightly proximal of it. Aspistomella duo , A. heteroptera , A. lobioptera , A. pachitea , A. steyskali , and A. tres also differ by the very narrow pterostigma formed by the approximate, subparallel veins Sc and R 1; costal vein more or less thickened, often strongly arcuate and bearing thickened marginal setulae before the apex of the subcostal vein. Aspistomella duo , A. heteroptera , A. obliqua , A. sachavaca , and A. tres can be distinguished by the presence of setulose vein R 1, which is rarely found in other groups of Lipsanini .

From the monotypic genus Polyteloptera , the species here assigned to Aspistomella differ by having an apically rounded postpedicel and a gradually narrowing wing with the long ultimate section of vein M 1 ( P. apotropa has an antenna with a dorsally incised and apically pointed postpedicel and an apically broadened wing, with the short ultimate section of vein M 1).

The species of Aspistomella are distinguished from the superficially similar, elongate and moderately large metallic greenish flies of the genus Ulivellia , by the crossvein r-m distal to the apex of vein R 1 (at the level of vein Sc or basal to it in Ulivellia ).

Description

Adult. Body mostly dark brown or black, usually with a metallic sheen, sometimes faint greenish or cyan, partly obscured by sparse whitish or silvery white microtrichia ( Figs 10 A, B View FIGURE 10 , 14 A, E View FIGURE 14 , 24 A–F View FIGURE 24 , 25 A–C View FIGURE 25 , 34 A–C View FIGURE 34 , 38 D View FIGURE 38 , 44 A–C View FIGURE 44 , and others).

Head at most slightly higher than long. Frons narrow (1.05× longer than wide in A. pachitea and 1.1× A. schnusei ) to wide (0.65× in A. duo , 0.9× in A. lobioptera ), conspicuously narrowed towards vertex, reddish or brownish-yellow with black, often greenish shining vertical plates and ocellar triangle ( Figs 10 D View FIGURE 10 , 14 C View FIGURE 14 and others); frontal vitta smooth or with fine longitudinal wrinkles ( Fig. 15 G View FIGURE 15 , left), frontal plates with 4–8 short proor lateroclinate parafrontal setulae on each side ( Figs 13–18 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 View FIGURE 17 View FIGURE 18 ), 2–6 frontal setae and 1–3 interfrontal setae ( Figs 10 C, D View FIGURE 10 , 15 A View FIGURE 15 , 22 E View FIGURE 22 , 24 C View FIGURE 24 , 25 D View FIGURE 25 , 27 B View FIGURE 27 , 28 C View FIGURE 28 , 31 C View FIGURE 31 , 32 G View FIGURE 32 , 34 D, E View FIGURE 34 , 36 C View FIGURE 36 , 38 B, C View FIGURE 38 , 39 C View FIGURE 39 , 40 A View FIGURE 40 , 42 F View FIGURE 42 , 44 D View FIGURE 44 ); vertex and orbits with dense, proclinate, slightly thickened, short white microtrichia ( Fig. 15 G View FIGURE 15 , right). Vertical plates with 1 long orbital seta, and usually with a second vestigial reclinate seta anterior to it; ocellar triangle with ocelli forming an elongated acute triangle and a pair of usually very long ocellar setae, 4–10× longer than frontal setae ( Figs 14 B View FIGURE 14 , 22 D View FIGURE 22 , 25 C View FIGURE 25 , and others) or, in A. garleppi , 1–1.5× longer than frontal setae ( Fig. 24 D View FIGURE 24 ). Face dorsally flat, covered with white or black, dense, inclinate, curled and appressed microtrichia ( Figs 15 F View FIGURE 15 , 25 D View FIGURE 25 , 38 C View FIGURE 38 and others), and with ventral portion conspicuously produced antero-ventrally, forming a large, often metallically shining epistome, covered with sparse, thin, erect whitish microtrichia ( Figs 14 C View FIGURE 14 , 15 I View FIGURE 15 and others). Parafacial usually brownish-yellow, densely white microtrichose ( Fig. 15 H View FIGURE 15 ). Gena widened posteriorly, brownish, sparsely white microtrichose, bearing 1–2 strong genal setae and 4–6 moderately or very long, proclinate peristomal setulae ( Figs 25 C View FIGURE 25 , 27 B View FIGURE 27 , 28 B, C View FIGURE 28 ). Occiput black or dorsomedially and lateroventrally brown to yellow, densely white microtrichose. Scape short, dorsally with 6–8 marginal setulae; pedicel with rectangular incision; one long pedicellar seta and 20–25 setulae, the longest ventral, almost as long as pedicel width ( Fig. 15 D View FIGURE 15 and others). Postpedicel oval, 2.0–2.2× longer than wide, rounded at apex, densely microtrichose; arista 3-segmented ( Figs 15 D, E View FIGURE 15 ). Palp elongate, 4–4.5× longer than wide and almost twice as long as postpedicel, white microtrichose, with 15–25 ventral and ventromedial setae almost as long as palp width and 1–2 apical setae 1.5–2× longer than the rest ( Fig. 15 B View FIGURE 15 ). Clypeus much lower than epistome, convex, densely microtrichose, almost entirely hidden in oral cavity. Proboscis with prementum and labellum moderately large, with long, often slightly curled, thin setulae ( Fig. 15 B View FIGURE 15 ).

Thorax mostly black or brown, with faint bluish, greenish or golden sheen and moderately dense, thin, semierect white microtrichia not completely hiding shining cuticle. Postpronotal lobe with 1 seta and 5–15 setulae; proepisternum with 1 short proepiesternal seta (sometimes absent or indistinct) and 5–20 fine subequal setulae on proepiesternal ridge. Prosternum higher than wide, with distinct longitudinal suture and shallow ventral incision, sparsely microtrichose, without conspicuous setae. Mesonotum steel shining, with slight green or bluish sheen of cuticle not entirely obscured by sparse or moderately thick white microtrichia ( Figs 14 E View FIGURE 14 , 16 A View FIGURE 16 ); scutum setulose, except prescutellar area posterior to dorsocentral setae; dorsocentral setulae forming distinct row, with 8–18 poorly ordered rows of setulae between them; 1 postpronotal, 2 notopleural, 1 postsutural supra-alar, 1 intra-alar and 1 postalar, 2 dorsocentral and 1 acrostichal seta present, strong (in A. crucifera , A. lobioptera , A. lunata , A. obliqua , A. quinquincisa , A. sachavaca , A. steyskali , and A. teresensis ), weak (in A. schnusei ,) or absent (in A. angustifrons , A. duo , A. garleppi , A. heteroptera Hendel , A. pachitea , and A. tres ). Anepisternum setulose almost entirely anterior to vertical squama, with one strong seta and 5–12 shorter setae at posterior margin. Katepisternum with one strong posterodorsal seta. Scutellum subtriangular, slightly convex, smooth, with 2 pairs of scutellar setae, no setulae on disc and margins, sparsely microtrichose. Subscutellum matt, microtrichose. Mediotergite smooth, sparsely or densely microtrichose.

Wing moderately wide, 2.6–2.8× longer than wide (in A. lobioptera , A. lunata , A. enderleini , and A. steyskali ) to strongly elongate, 3.5–3.75× longer than wide (in A. tres ), largely dark with hyaline incisions or round spots or hyaline with darker crossbands ( Figs 5 View FIGURE 5 , 6 View FIGURE 6 ). Venation modified, pterostigma shorter than wide in A. duo , A. heteroptera , A. lobioptera , A. pachitea , A. steyskali , and A. tres ), and costal vein conspicuously bent and thickened before apex of subcostal vein, so that apical portion of costal cell conspicuously lobed with thick setulae on costal vein ( Figs 5 B–F View FIGURE 5 , 16 E, F View FIGURE 16 ), or, in other species, as long as or longer than wide. Vein R 1 dorsally with 3–10 setulae ( A. duo , A. heteroptera , A. obliqua , A. sachavaca , and A. tres ) to entirely bare. Crossvein r-m apical to R 1 apex in most species, except in line with R 1 apex in A. lunata , A. sachavaca , and A. schnusei or slightly basal of it in A. garleppi Cell r 4+5 slightly or conspicuously narrowed apically. Vein CuA Z-shaped, cell cua with moderately short (in most species) to long (in A. obliqua and A. sachavaca ) posteroapical lobe along vein CuP. Calypters white, with white cilia. Halter creamy white (in most species) to brown with black or brown knob (in A. duo and A. tres ).

Legs variably coloured; coxae usually yellow to brown, femora yellowish brown to entirely brown or black, tibiae and tarsi yellow to brown. Fore femur with 2 posterodorsal rows of setae; posteroventrally with row of 3–5 setae (in A. duo and A. tres ), often conspicuously thickened and spinulose, in A. pachitea without postero-ventral row; fore tibia antero-apically as well as basal fore tarsomere with brush of short pale setulae. Mid femur on anterior and posterior surfaces with row of moderately long, antero- and postero-ventrally directed setulae. Mid tibia apicoventrally with strong spur-like seta 1.5–3× longer than tibia width, in A. duo , A. obliqua and A. tres with additional seta ( Fig. 16 N View FIGURE 16 ) 0.7–1× longer than longest seta. Hind femur with 2–3 to 4–5 preapical setae dorsally.

Abdomen subshining brown to black, in A. heteroptera with syntergite 1+2 broadly yellow ( Figs 25 A, B View FIGURE 25 ); tergites and sternites with metallic silver, green or yellow sheen, sparsely white microtrichose ( Figs 10 G View FIGURE 10 , 16 C, D View FIGURE 16 , 34 B View FIGURE 34 , 36 G, H View FIGURE 36 ). Male and female abdomen with 5 visible tergites, of which tergites 3–5 subequal in length; female tergite 6 hidden beneath posterior margin of tergite 5. Sternites 3–5 not modified, subrectangular ( Figs 11 A View FIGURE 11 , 12 A View FIGURE 12 , 18 A View FIGURE 18 , 23 A View FIGURE 23 , 35 A View FIGURE 35 , 37 A View FIGURE 37 , 41 G View FIGURE 41 ).

Male postabdomen. Sternite 8 setulose, with 2 longer setulae. Epandrium moderately setulose. Surstyli of variable shape, often species-specific, fused with epandrium, usually wide basally, narrowed and curved mesally towards apex, often with small, mesoapically directed pimple-like process ( Figs 26 E View FIGURE 26 , 35 C View FIGURE 35 , 46 E View FIGURE 46 : pi p), in A. angustifrons , very narrow and curved ( Figs 11 C, F View FIGURE 11 ), in A. quinquincisa , blunt with smooth margins ( Figs 37 B–F View FIGURE 37 ), in A. enderleini , blunt with serrate posterior margin ( Figs 23 B–D View FIGURE 23 ), in A. lobioptera and A. steyskali , bilobate ( Figs 29 D–G View FIGURE 29 , 41 A–D View FIGURE 41 ). Cerci low, moderately protruding posteriorly, flattened and almost round in A. duo and A. tres ( Figs 16 B, D View FIGURE 16 , 46 A, B View FIGURE 46 : cerc), elongate and bilobate, partly connected in A. heteroptera , A. obliqua , and A. pachitea ( Figs 26 C, D View FIGURE 26 , 33 A, B, D View FIGURE 33 , 35 C, D View FIGURE 35 ), short, button-like in A. angustifrons ( Fig. 11 E View FIGURE 11 ), flat in A. enderleini , A. lobioptera , A. quinquincisa , and A. steyskali ( Figs 23 B, D View FIGURE 23 , 29 D–F View FIGURE 29 , 37 E, F View FIGURE 37 , 41 A–E View FIGURE 41 ), moderately long setulose. Subepandrial sclerite short, horseshoe-shaped, with ventral arms entirely integrated into surstylus, bearing a row of mesally directed setulae anteriorly ( Figs 23 B View FIGURE 23 , 29 D, E View FIGURE 29 ), without thickened tooth-like setulae (prensisetae), or with 3–4 sharp thickened subapical setae (in A. quinquincisa and A. steyskali ) ( Figs 37 E, F View FIGURE 37 , 41 A, B View FIGURE 41 ) or with 1–2 thickened and 2–3 fine setulae (in A. heteroptera ) ( Fig. 26 E View FIGURE 26 ). Hypandrium narrow, U-shaped, joined to basiphallus by thin membrane; phallapodeme with paired and rather long, sagitally flattened anterior arms, continuing into a pair of ventrally directed ridges or folds, forming a gutter-like phallic guide on both sides of basiphallus and basal part of distiphallus ( Figs 23 D–F View FIGURE 23 , 29 F View FIGURE 29 , 35 G View FIGURE 35 , 37 E, F View FIGURE 37 , 41 A, D, E View FIGURE 41 ); phallapodeme itself usually very short ( Fig. 46 C View FIGURE 46 ). Pregonites plate-like, almost symmetrical, antero-medially attached to phallapodeme and latero-ventrally to hypandrium by membrane, each bearing 4–6 setulae ( Fig. 33 E View FIGURE 33 ); in A. obliqua very strongly displaced and posterior to postgonites ( Figs 11 H View FIGURE 11 , 23 D View FIGURE 23 , 26 F View FIGURE 26 , 29 F View FIGURE 29 , 37 F View FIGURE 37 , 41 D View FIGURE 41 ). Postgonites symmetrical, reduced to oval sensillar plates, bearing 4–5 setulae located on membrane on lateral sides of phallic guide at level of anterior part of basiphallus ( Figs 11 H View FIGURE 11 , 23 D View FIGURE 23 , 26 F View FIGURE 26 , 29 F View FIGURE 29 , 33 E View FIGURE 33 , 37 F View FIGURE 37 , 41 D View FIGURE 41 ).

Phallus simple, band-like or tubular, moderately short in most species, usually 2–5× longer than epandrium ( Figs 11 B, C View FIGURE 11 , 17 K View FIGURE 17 , 23 B, C View FIGURE 23 , 26 A, B View FIGURE 26 , 33 B View FIGURE 33 , 35 C, D View FIGURE 35 , 37 B, C View FIGURE 37 , 41 A–F View FIGURE 41 , 46 A, B View FIGURE 46 ), in A. lobioptera very long, 6–8× longer than epandrium, with moderately large ring of basiphallus ( Figs 23 B, D View FIGURE 23 , 29 F View FIGURE 29 ) and simple distiphallus represented is a bare or short spinulose, densely trichose in A. lobioptera ( Fig. 29 C View FIGURE 29 ), flattened tube with a pair of narrow sclerotised stripes.

Ejaculatory apodeme usually with fan-shaped apical part 2–3 as long as moderately developed sperm pump ( Figs 17 J View FIGURE 17 , 23 C View FIGURE 23 , 26 G View FIGURE 26 , 29 B View FIGURE 29 , 35 E View FIGURE 35 , 37 C View FIGURE 37 ).

Female terminalia. Oviscape short, usually half as long as abdomen. Eversible membrane ( Figs 12 A View FIGURE 12 , 18 B View FIGURE 18 ) as long as aculeus, with 2 pairs of bare taeniae reaching its posterior 4/5; membrane finely microspinulose in anterior half. Aculeus ( Figs 12 B View FIGURE 12 , 18 C View FIGURE 18 ) narrow and moderately long, 8–11× longer than wide, with elongate oval cercal unit bearing 2–3 pairs of long setae (basal dorsal, subapical lateroventral and somewhat shorter apicodorsal) and several shorter setulae on ventral and latero-ventral sides; anal opening (slit) on dorsal side of cerci ( Figs 12 B View FIGURE 12 , 18 D View FIGURE 18 ); sternite 8 well sclerotised, with indistinct setulae on each side. Vagina ( Fig. 30 D View FIGURE 30 ) with simple, finger-like, apically rounded ventral receptacle as in all other Ulidiidae . Two spherical or somewhat elongated spermathecae ( Figs 12 C View FIGURE 12 , 18 E View FIGURE 18 , 30 B View FIGURE 30 , 43 E View FIGURE 43 ); short, invaginated “necks” at junctions of spermathecae with ducts.

Preimaginal stages

Egg known only for A. lobioptera , elongate oval, 4.5× longer than wide, slightly wider than aculeus, without stalks or tapering rear end ( Fig 30 C View FIGURE 30 ).

Third instar larvae. Aspistomella larvae are known from A. duo , A. tres and an unidentified third species. Larva whitish, maggot-like, medium-sized (7.5–12 mm long) and mostly smooth. Pseudocephalon with deep incision between cephalic lobes. Facial mask with 20–28 laterally bifurcated or double bifurcated furrows separating subparallel oral ridges, each with fringe of blunt scales ( Figs 19 C, D View FIGURE 19 ). Creeping welts on abdominal segments I–VII and caudal segment with spinules, anterior spiracles fan-shaped. Caudal segment posterodorsally truncate, with sclerotised, slightly elevated, rounded posterior spiracles. Each spiracular plate with three very long, sinuous spiracular slits, spiracular plate mostly dark, but yellowish along spiracular slits (= yellow slit stripes) ( Figs 9 A, B View FIGURE 9 ). Cephalopharyngeal skeleton ( Figs 7 A, B View FIGURE 7 ). Mouthhook with elongated base with semitransparent window, long and thin, ventrally curved apical tooth and moderately long and narrow, ventrally produced ventral apodeme, moderately short hypopharyngeal sclerite.

Puparium ( Fig. 9 G View FIGURE 9 ) elongate cylindrical, reddish brown, strongly tapering anteriorly and broadly truncate posteriorly; anterior spiracles, posterior spiracles and creeping welts as described for third instar larva.

Habitat. The larvae of Aspistomella duo , A. tres and A. sp. live in the water-filled internodes of young bamboo culms of Guadua angustifolia . The biology of Aspistomella is described in the Biology section of A. duo .

Remarks. The monophyly of the genus is doubtful, and the results of a morphology-based phylogenetic analysis neither strongly support nor refute it. Here we include in Aspistomella all species that do not have the diagnostic characters of Polyteloptera and / or Ulivellia . There is no evidence that they are nested within Aspistomella , and we consider them to be separate genera.

The diagnostic character proposed by Hendel (1909b, 1910) to separate Paraphyola from Aspistomella , namely a narrow wing with almost parallel anterior and posterior margins, shows a similar condition with a gradual transition to "moderately oval" wings in A. duo , A. crucifera , A. garleppi , A. obliqua , A. quinquincisa , A. schnusei , A. teresensis , and A. tres , so we prefer to place them all in Aspistomella together with Paraphyola angustifrons rather than separating them into two genera for ease of identification. As male genitalia are not examined in many species and molecular data are not available to provide more robust results, we consider the current generic classification to be tentative.

Steyskal (1968: 54.20) erroneously stated P. angustifrons to be the type species of Paraphyola by monotypy. However, Hendel (1909a) originally described two species, but did not designate any of them as the name-bearing type. It was only in the later published generic synopsis of the ulidiids in the series “Genera Insectorum” ( Hendel, 1910) that he clearly stated that his type species was Paraphyola angustifrons Hendel, 1909 . The latter is therefore the type species of the genus according to the later designation by Hendel (1910).

The unknown ulidiid larva found by DK in water-filled bamboo internodes probably belonged to Aspistomella , because CW1 had three rows of spinules (and not five as in Ulivellia ) and all other details of its creeping welts resembled A. tres . The spiracular slits of the unknown Aspistomella sp. larvae were clearly identifiable as belonging to a distinct species, because they had only a few turns and the yellow area above the spiracular slits was very wide compared to the larvae of other ulidiid species ( Fig. 9 F View FIGURE 9 ). Furthermore, the shape of the anterior spiracles was more angular than in Aspistomella duo and A. tres .