Aspistomella group of genera

Within the tribe, the genera Aspistomella, Polyteloptera, and Ulivellia form a group here called the Aspistomella group, which differs from other genera of Lipsanini by the combination of a head with a moderately or very large epistome (lower part of the face), strongly anteroventrally produced and conspicuously (usually 2×) higher than the low clypeus (synapomorphy) almost hidden in the peristomal cavity (synapomorphy).

The Aspistomella group of genera belongs to a broader monophyletic lineage (here called the Amethysa lineage) together with the taxa sharing frontal setulae modified to form long and strong frontal and interfrontal setae (synapomorphy); row of fine and short parafrontal setulae 3–5× shorter than frontal setae (synapomorphy); very long ocellar seta (usually 2× or more as long as the postpedicel); very long inner vertical seta (slightly longer than the ocellar seta); short outer vertical seta (at most half as long as inner vertical seta or vestigial) (apomorphies), often setulose vein R 1 (plesiomorphy; secondarily bare in some species); unmodified, relatively short aculeus with tergosternite 8 moderately wide and oval in section (plesiomorphy) and cercal unit oval, not flattened and bearing long setulae (plesiomorphy) (Kameneva & Korneyev, in press).

Other taxa of the Amethysa lineage are distinguished by the low, less produced epistome combined with a high clypeus almost as high as the epistome (except those either without epistome of a receding face ( Eumetopiella, Stenomyia) or, if the epistome is antero-ventrally produced ( Steneretma, Zacompsia), then with a high clypeus (Kameneva & Korneyev, in press).

The genera of Lipsanini, except those of the Amethysa lineage, are easily distinguished by the uniformly short, undifferentiated (plesiomorphy), subequal inner and outer vertical setae (plesiomorphy).Among them, many species assigned to Acrosticta, Acrostictomyia, Axiologina, Euxesta, and Pareuxesta share a very narrow and long aculeus, 1.5× longer than the oviscape (synapomorphy), and apparently form another monophyletic lineage (Kameneva & Korneyev, in press).

The species assigned here to the genera of the Aspistomella group often have dorsoapically setulose vein R 1 (possible plesiomorphy, occurring occasionally in different lineages of Lipsanini and Pterocallini, but very common in the Otitini and Myennidini, black halteres (possible apomorphy, not found in most other Ulidiidae), and sinuate tremae of the larval posterior spiracle (possible apomorphy of the few Aspistomella and Ulivellia whose larvae are known, but not found in the other Ulidiidae), further supporting the inclusion of the genera Aspistomella and Ulivellia in a monophyletic lineage.

The species assigned here to the genera of the Aspistomella group have male genital structures so diverse that they would merit numerous separate genera, but we prefer to include most of them in the genera Aspistomella and Ulivellia . Morphology-based phylogenetic analysis does not provide a reliable resolution of their relationships, and the subdivision of this group into genera is tentative.

Many of the species discussed below are known from single specimens or only a few female specimens, so their descriptions lack male genitalia and can only be provisionally assigned to genera. Further study of additional material is required.

Key to adult Aspistomella and related genera

1 Vein r-m far proximal to R 1 apex, at level with Sc apex; postero-apical lobe of cell cua shorter or at most as long as cell width; wing <3.5× longer than wide (Figs 4 A–G, I–K)............................................................. 2

- Vein r-m distal to R 1 apex (Figs 5, 6 A, C–H), and if slightly proximal in Aspistomella garleppi (Fig. 6 D), then distal to Sc apex level and wing> 3.5× longer than wide.................................................................... 9

2 Epistome low, clypeus as high as epistome (Fig. 3 D)......................................................... 3

- Epistome high, at least 2× higher than clypeus (Figs 3 A, C)........................................ Ulivellia …… 4

3 Frontal and interfrontal setae 2–3 longer than fine parafrontal setulae (Fig. 3 D). Wing pattern as in Figs 4 I, J: subcostal crossband separated from preapical crossband in cell R 1; basicostal cell black or yellowish................................................................................... “ Euxesta” insolita Hendel and related undescribed taxa

- Frontal vitta with uniformly short, undifferentiated setulae (as on Fig. 3 B). Wing pattern as on Fig. 4 K: subcostal and preapical crossbands connected in pterostigma; basicostal cell black............................................. Axiologina

4 Vein R 1 at pterostigma slightly dipping downwards, thickened and setulose; basal 0.8 of costal cell brown; vein R 2+3 at apex close and subparallel to costa, turning towards it before very apex. Wing sexually dimorphic: male with broad brown pattern, costa strongly bent at middle; female with 4 partly fused brown bands and moderately bent costa (Figs 4 D, E)................................................................................................ U. arcuata sp. nov.

- Vein R 1 at pterostigma straight, neither thickened nor setulose; at most basal half costal cell brown; vein R 2+3 variable. Wing either equal in both sexes, narrowly banded, or only one sex is known, costa only slightly bent anteriorly................ 5

5 Discal crossband (DB) oblique, ending just at base of vein CuA+CuP (Figs 4 F, G)................................. 6

- Discal crossband (DB) angulate, <-shaped, with posterior part directed posteroapically, terminating just at the apex of vein CuA+CuP (Figs 4 A–C)................................................................................ 7

6 Wing narrow,> 3.1× longer than wide, hyaline interspace between dark discal and preapical crossbands> 2.5× broader than discal crossband in discal cell (Fig. 4 F). Legs and halter at least partly yellow. Prescutellar acrostichal setae absent............................................................................................. U. tenoris sp. nov.

- Wing wider, <3.1× longer than wide, hyaline interspace between dark discal and preapical crossbands <2× broader than discal crossband in discal cell (Fig. 4 G). Legs and halter entirely black. Prescutellar acrostichal setae present.................................................................................................. U. pseudinsolita sp. nov.

7 Cell br entirely brown, connecting subbasal and discal crossbands (Fig. 4 A)....................... U. amnoni sp. nov.

- Cell br partly hyaline, subbasal and discal crossbands separated (Figs 4 B, C)...................................... 8

8 Subapical part of vein R 2+3 almost straight, leaving arcuate hyaline area between it and connection of subapical and apical brown crossbands (Fig. 4 B)............................................................... U. inversa Speiser

- Subapical part of vein R 2+3 conspicuously bent anteriorly, leaving no hyaline area between it and connection of subapical and apical brown crossbands (Fig. 4 C)........................................................ U. laetitiae sp. nov.

9 Wing conspicuously widened and shortened in apical half; apical section of vein M 1 shorter than the preapical section between crossveins r-m and dm-m; postero-apical lobe of cell cua at most as long as cell width (Fig. 4 H). Vein R 1 bare. Postpedicel dorsally incised and apically pointed (Figs 48 E, F).................................. Polyteloptera apotropa Hendel

- Wing gradually narrowed and elongated in apical half; apical part of vein M 1 longer than the preapical part between crossveins r-m and dm-m (Figs 5, 6). Vein R 1 either setulose or bare. Postpedicel rounded apically (Fig. 3 C)...... Aspistomella … 10

10 Pterostigma vestigial, conspicuously shorter than width of costal cell (Figs 5 A–F)................................. 11

- Pterostigma either longer than width of costal cell (Figs 6 B–H) or at most slightly shorter than its width (in A. lunata, A. enderleini sp. nov. and A. sachavaca sp. nov.) (Figs 5 G–H, 6 A).............................................. 16

11 Costal vein bent and thickened anteriorly before the apex of vein Sc; pterostigma at least slightly wider than veins Sc and R 1; vein R 1 bare or setulose dorsally; wing dark with hyaline spots, incisions or bands in the posterior half (Figs 5 B–F)...... 12

- Costal vein neither bent nor thickened before the apex of vein Sc, pterostigma almost linear, narrower than veins Sc and R 1; vein R 1 bare; wing with hyaline or pale yellow anterior margin and gradually darkening towards posterior margin without hyaline spots or incisions (Fig. 5 A).............................................................. A. pachitea sp. nov.

12 Face between antennae from lunule to epistome completely sooty black microtrichose (Fig. 25 D). Wing apex with long preapical hyaline incision from cell m only into cell r 2+3, dividing brown area into two dark apical bands; cell m with 2 hyaline marks (Fig. 5 B)..................................................................... A. heteroptera Hendel

- Face between antennae from lunule to epistome white or gray microtrichose (Figs 14 D, 22 E). Wing pattern different: cell m with 1 hyaline spot only (Figs 5 C–F).................................................................... 13

13 Wing apex completely dark; cell m with wide basal hyaline spot (Figs 5 C–D); vein R 1 with several setulae dorsally; prescutellar acrostichal setae absent; halter with black knob............................................................. 14

- Wing apex with long and narrow preapical hyaline incision from apical half of cell m into cell r 1 usually reaching anterior margin of wing and separating narrow crescent-shaped brown apical band; base of cell m completely dark (Figs 5 E–F); vein R 1 bare; prescutellar acrostichal setae present; halter yellow................................................... 15

14 Wing very narrow,> 3.5× longer than wide; anterior hyaline incision (distal to pterostigma) entering only into cell r 2+3 basal to crossvein r-m, but not cells br, nor r 4+5; base of cell r 4+5 and apex of cell dm with common oblique spot (Fig. 5 D).................................................................................................. A. tres sp. nov.

- Wing somewhat wider, <3.5× longer than wide; anterior hyaline incision (distal of pterostigma) entering dm through cells r 2+3 and r 4+5 distal to crossvein r-m, but apex of cell dm entirely dark (Fig. 5 C)............................ A. duo sp. nov.

15 Cell dm entirely dark in apical half (Fig. 5 E). Male genitalia: surstyli with short lobes and slightly thickened setae; lobes of phallic guide unmodified; phallus thick and extremely long, densely trichose (Fig. 29).............. A. lobioptera Hendel

- Cell dm apically of r-m level with hyaline spot connected to hyaline spot in cell m 4 (=cua 1) (Fig. 5 F). Male genitalia: outer surstylus with elongate anteroventral lobe and wide rounded posterior lobe, inner surstylus with 3–4 thick prensisetae and posteriorly produced; lobes of phallic guide sclerotised and apically truncated; phallus non-modified, moderately developed (Figs 41 A–F)......................................................................... A. steyskali sp. nov.

16 Cell r 1 with 2 hyaline marks (Figs 5 G, H) (if in A. sachavaca sp. nov. with unclear indentation from cell r 2+3 (Fig. 6 A), then wing short oval) or almost entirely hyaline with 1–2 narrow dark marks (Fig. 6 B)................................. 17

- Cell r 1 with 1 hyaline mark (Figs 6 D, G, H)............................................................... 23

17 Wing wide oval, <2.6× (2.3–2.5×) longer than wide (Figs 5 G, H).............................................. 18

- Wing long,>2.6× (2.7–4×) longer than wide (Figs 6 B, E, F).................................................. 20

18 First hyaline mark in cell r 1 reaching at most vein M 1 and isolated from hyaline mark at posterior margin of the wing (Figs 5 G, H). Face entirely white or grey microtrichose (Figs 22 E, 31 C). Vein R 1 bare..................................... 19

- First hyaline mark in cell r 1 complete, reaching posterior margin of the wing (Fig. 6 A). Face below lunule sooty black microtrichose (Fig. 38 C). Vein R 1 setulose dorsoapically..................................... A. sachavaca sp. nov.

19 First hyaline incision distal to pterostigma long, extending into cell r 4+5 distally of crossvein r-m (Fig. 5 G). Male genitalia not examined.................................................................... A. lunata (Hendel) comb. nov.

- First hyaline incision distal to pterostigma short, extending at most into cell r 2+3 and isolated from round hyaline spot in cell r 4+5 distally of crossvein r-m (Fig. 5 H). Male genitalia: surstyli ventrally obtuse, with short denticles on posterior margin, but without expressed lobes and prensisetae, only with slightly thickened setae on surstyli, lobes of phallic guide laterally triangular and moderately sclerotised (Figs 23 B–E)................................................. A. enderleini sp. nov.

20 Wing apex mostly hyaline, with two narrow oblique dark crossbands (Fig. 39 A). Epistome conspicuously produced anteriorly beyond antennae (Fig. 39 D). Abdominal tergites 1–4 covered with moderately long and dense microtrichia, matt (Figs 39 E, G)................................................................................. A. schnusei sp. nov.

- Wing apex broadly dark (Figs 6 C, E, F). Epistome shorter, not produced anteriorly beyond antennae (Figs 10 B, 36 D, 42 D). Abdominal tergites subshining.......................................................................... 21

21 Wing with crescent-shaped subapical hyaline mark; posterior margin dark, without triangular hyaline incisions or spots in cell m 4 (Fig. 6 C). Femora largely black.......................................... A. angustifrons (Hendel) comb. nov.

- Wing apex with subapical hyaline marks in cells r 1 and m 1 isolated; posterior margin with hyaline marginal mark in cell m 4 (Figs 6 E, F). Femora yellow................................................................................ 22

22 Distal hyaline mark in cell r 1 reaching anterior half of cell r 4+5; cell m 1 with rounded submarginal hyaline mark extending to vein M 1 (Fig. 6 E)............................................................... A. crucifera (Hendel) comb. nov.

- Distal hyaline mark in cell r 1 posteriorly reaching only middle of cell r 2+3; cell m 1 with cuneiform hyaline mark extending middle of cell r 4+5 (Fig. 6 F).......................................................... A. quinquincisa sp. nov.

23 Cell r 1 with hyaline marginal incision extending only to cell dm (Fig. 6 G). Vein R 1 bare............. A. teresensis sp. nov.

- Hyaline interspace distally to pterostigma continuous, reaching posterior margin of wing (Figs 6 D, H). Vein R 1 setulose in apical part.......................................................................................... 24

24 Wing 3.2–3.3× longer than wide; dark subapical crossband uniformly narrow, cell m 1 with hyaline area in basal half (Fig. 6 H). Face below lunule with medial black spot, partly silvery microtrichose (Fig. 32 G). Ocellar seta very long (Figs 32 C, D). Mid tibia ventroapically with 2 long spur-like setae............................................... A. obliqua sp. nov.

- Wing 3.8–4× longer than wide; wing apex from crossvein dm-m uniformly brown, including cell m 1; hyaline area between it and pterostigma wide, covering entire area between r-m and dm-m (Fig. 6 D). Face entirely silvery microtrichose, without black spot. Ocellar seta short, at most 1/3 as long as orbital seta (Figs 3 C, 24 D). Mid tibia ventroapically with 1 long spur-like seta................................................................................. A. garleppi sp. nov.