Anthomyza ornata Roháček 2018, sp. nov.
Creators: name: Roháček, Jindřich
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Anthomyzidae
Anthomyza
Anthomyza ornata

description: Anthomyza ornata sp. nov.
(Figs 82, 83, 86–95)
Type material. HOLOTYPE: ♀, labelled: ‘ CHINA, Sichuan prov., Leshan, EMEISHAN, Leidonping, above cable car station, 2570m, 29°32′02′′N, 103°19′58′′E, 10. vi. 2014, sweeping on veg., J. Hájek, J. Růžička & M. Tkoč lgt.’ and ‘ Holotypus ♀, Anthomyza ornata sp. n., J. Roháček det. 2017’ (red label) (NMPC, genit. prep.).
Description. Male unknown.
Female. Total body length 2.78 mm; bicolourous, yellow and dark brown (Fig. 83), with thorax longitudinally variegated, sparsely whitish grey microtomentose, subshining. Head yellow except for occiput and ocellar triangle, somewhat higher than long, in profile rounded anteriorly (frons not projecting in front of eye). Occiput dorsomedially concave, entirely dark brown, subshining due to sparse whitish grey microtomentum. Frons bright yellow, with only ocellar triangle brown, largely microtomentose and dull, only frontal (including ocellar) triangle subshining. Orbit anteriorly (up to posterior ors) lighter yellow, sparsely whitish microtomentose and slightly shining. Frontal triangle relatively broad, equilateral, reaching anterior two-fifths of frons, dark yellow to ochreous except for brown ocellar triangle. Frontal lunule small, orange yellow. Face narrow, weakly sclerotized and deeply concave, dull yellow and whitish microtomentose; parafacialia and gena whitish yellow, with dense silvery white microtomentum, both bordered by narrow ochreous marginal stripe; postgena whitish yellow to dirty yellow, sparsely whitish microtomentose and sharply delimited from adjacent dark brown ventrolateral part of occiput; mouthparts yellow with ochreous clypeus and yellowish white palpus. Cephalic chaetotaxy: all macrosetae very long (see Fig. 82) and hence most similar to those of A. sulphurea (see below); pvt relatively long and strongly crossed; vti extremely long, distinctly longest of cephalic setae (as long as longest eye diameter); oc subparallel, somewhat longer than vte and 2 (posterior) ors (these 3 subequal) but all also very long; 3 ors, posterior (more exclinate) and middle (slightly reclinate) subequal, anterior markedly shorter, only about one-fourth of the middle ors; 1 microsetula (about as long as medial microsetulae) in front of foremost (short) ors; 3–4 pairs of medial microsetulae between apex of frontal triangle and anterior margin of frons; 1 distinct inclinate setula (as long as uppermost postocular) behind vte; postocular setulae sparse (6) and relatively long (dorsal ones in particular), in single row; lateroventral part of occiput and postgena with a number of setulae, 1 longer but fine seta in posteroventral corner; 1 vi (distinctly shorter than both long ors); subvibrissa weak (or absent?), somewhat longer (on left) or shorter (on right) than longest peristomal setula; the latter sparse (6) and about as long as postocellars but finer. Palpus slender and rather long, with 1 relatively long and dark preapical seta and with 7–8 (all dark) ventral and lateral setulae; labella fleshy, broad and finely setulose (see Fig. 82). Eye larger than that of A. sulphurea, suboval to broadly reniform, with longest diameter slightly oblique and about 1.3 times as long as the shortest. Gena distinctly lower than in A. sulphurea (see Fig. 82), with shortest height 0.14 times as long as shortest eye diameter. Antenna dark yellow (scape, pedicel) to pale yellow (1st flagellomere); pedicel with dorsal seta longer than usual; 1st flagellomere elongately suboval, laterally flattened and with relatively long white cilia on anteroventral margin. Arista dark brown including thickened basal segment, about 2.2 times as long as antenna, distinctly brown ciliate although shorter than is 1st flagellomere.
Thorax slightly wider than head, yellow and dark brown striped (thoracic pattern most resembling that of Epischnomyia triarmigera), sparsely whitish grey microtomentose, subshining. Mesonotum largely yellow but with broad dark brown vittae between dc and prs-sa lines that are anteriorly fused (thus medial yellow area not reaching anterior margin of mesonotum) and posteriorly narrowly continuing on sides of otherwise yellow scutellum. Humeral and notopleural areas up to wing base whitish yellow. Pleuron dorsally with broad dark brown band extended from propleuron to base of abdomen (see Fig. 83); ventral part of pleuron pale yellow to yellowish white. Postscutellum bulging (Fig. 83) and dark brown; postnotum dark only medially, pale brown to ochreous laterally. Thoracic chaetotaxy rich, with most macrosetae unusually long (as in A. sulphurea): 1 hu (as long as anterior npl but finer); 2 npl (posterior much shorter); 1 exceptionally long prs and 1 subequally long or slightly longer sa; 1 pa (shorter and thinner than sa); 3 postsutural dc: posterior extremely long and robust (together with apical sc longest thoracic seta), middle also very long (as long as or longer than sa), anterior fine and only about half length of middle dc; 6–7 dc microsetae in front of them (1 dc microseta can also be between anterior and middle dc); only 2 rows of relatively long ac microsetae; hindmost ac pair (situated slightly beyond middle dc) only slightly longer than others; 2 sc, laterobasal fine and only slightly longer than foremost dc, apical strong and very long; 1 relatively long upcurved ppl (reaching to dorsal margin of propleuron) and 1 downcurved microseta below it; 2 stpl, posterior long, anterior somewhat shorter; 1 setula in front of anterior stpl and 3 setulae below it; ventral corner of sternopleuron with 5–6 setae, 2–3 of them longer and curved. Scutellum rounded triangular, very slightly convex to flat dorsally, about 1.7 times as wide as long. Legs uniformly yellow to yellowish white (coxae), at most apical half of last tarsal segment somewhat darkened, ochreous. f 1 (Fig. 88) with usual posterodorsal and posteroventral rows of long setae but ctenidial spine reduced though less so than that of A. sulphurea; f 2 and f 3 simply uniformly setulose, as are also all tibiae, except for t 2 having a distinct ventroapical seta and a pair of anteroventral small setae on apex (Fig. 87); fore and hind basitarsus (Fig. 91) each with 3 pale-pigmented proximoventral setulae, mid basitarsus (Fig. 87) with 1 longer and 1 short dark proximoventral enlarged setulae. Wing (Fig. 83) long and relatively broad, with ochreous to pale yellow veins and pale ochreous hyaline membrane. C with very distinct spine-like setae between apices of R 1 and R 2+3. R 2+3 long, sinuous, parallel to C but apically upcurved to it; R 4+5 slightly but distinctly bent, running paralellel to C but gradually converging with (almost straight) M. Discal (dm) cell large and long, with r-m situated at basal two-fifths of cell. Apical portion of CuA 1 slightly shorter than dm-cu and not reaching wing margin; A 1 short, ending far from it. Alula relatively large but narrowed and with apex rounded; anal lobe well developed. Wing measurements: length 3.69 mm, width 1.19 mm, Cs 3: Cs 4 = 1.95, rm\dm-cu: dm-cu = 2.86. Haltere with dirty yellow stem and yellowish white, relatively small, knob.
Abdomen unusually narrower than high (laterally somewhat compressed). Preabdominal terga brown to blackish brown, very sparsely greyish microtomentose only medially, glabrous and lustrous laterally (as also is most of postabdomen). T1 and T2 partly (laterally) fused; T1 shorter and narrower than T2 and with a few short setulae laterally; T2–T5 subequal in length, very transverse but overlapping, strongly bent far onto ventral aspect of abdomen and hence covering sterna in lateral view (cf. Figs 83, 86), all with relatively long but fine and dense setae (those at posterior margin longest). Preabdominal sterna whitish yellow, narrower, and hidden in ventral concavity of abdomen (but this probably is not true for gravid females). S2–S5 becoming somewhat wider posteriorly (S5 largest) but all as long as or longer than wide. S1 not observed; S2–S5 with long but fine setae being denser in more posterior sterna.
Postabdomen (Figs 86, 89, 90) medium long, tapered from 7th segment. T6 large, as wide as T5, dark brown (except for short pale posteromedial area, see Fig. 90) although lighter than T7, bent onto ventral aspect of segment as preabdominal terga, setose in posterior two-thirds, with setae at posterior margin long. S6 (Fig. 89) wider than S5 but similarly whitish yellow, weakly sclerotized but with longer setae posteriorly, hidden in ventral concavity between margins of T6 (cf. Fig. 86). T7 blackish brown (darker than T6), somewhat tapered posteriorly and dorsomedially shorter than laterally (Fig. 90), far expanded onto ventral aspect of 7th segment and embedding 7th spiracles (cf. Fig. 89), with abundant setae including longer ones at posterior margin. S7 (Fig. 89) submembranous, unpigmented, lying in ventral conca- vity of 7th segment; it is tapered posteriorly but without delimited margins, distinctly micropubescent and longsetose, particularly posteriorly; moreover there is a pair of long setae in membrane behind S7 surrounded by some micropubescence (see Fig. 89). T8 small, flat, wider than long, brown-pigmented except for posterior pale band and anterolateral corners (Fig. 90), with only a few setae laterally. S8 about as long as T8, medially divided into 2 distinctly pigmented sclerites being posteriorly bent dorsally and anteriorly becoming somewhat invaginated (cf. Figs 86, 93); external side of S8 finely setose and micropubescent as is usual in Anthomyza. Genital chamber of medium length but relatively broad (Figs 93, 95) with 3 sclerotizations: a posterior pair of crooked sclerites, annular sclerite (large, broad, transverse and bent onto lateral surfaces of genital chamber as in A. sulphurea) and a transverse wing-like sclerite posterior to ventral receptacle (Fig. 95). Ventral receptacle (Figs 94, 95) not very long but tube-like and curved, membranous, composed of broader proximal part with plain surface, middle part with very finely ringed surface and distal part gradually attenuated, twisted several times and having blunt apex. Accessory gland small, on a distally dilated and ringed duct (Fig. 93). Spermathecae (1+1) also distinctive (Fig. 92), each elongately cylindrical, with shallow terminal invagination, surface with fine dense transverse rings except for basal fourth, several short spinulae proximally near duct insertion and cervix reduced to very short collar (this as in A. sulphurea); spermathecal duct very long, simple. T10 small, transversely oval, brownish pigmented (Fig. 90), with single medial pair of very long setae (much longer than those on cercus) in centre and some sparse micropubescence. S10 much larger than T10 (Fig. 89), somewhat longer than wide, finely setulose and densely micropubescent. Cercus of moderate size, relatively slender, with abundant but not very long setosity, apical and dorsopreapical setae only slightly longer than other long setae of cercus (Figs 86, 90).
Discussion. Although only a single female of this Anthomyza species was available for study I did not hesitate to describe it because the species is extraordinary in many features including colouration, chaetotaxy as well as postabdominal structures. Its distinctive longitudinal thoracic pattern (most similar to that of Epischnomyia species which differ in having wings with brown and white longitudinal pattern, cf. Fig. 69) is sufficient to distinguish A. ornata sp. nov. from all other Anthomyza species. When combined with very long cephalic (vti in particular) and thoracic macrosetae (especially the unusually long prs and sa, with only 2 rows of ac microsetae), proximoventral seta on mid basitarsus (all unusual in Anthomyza) and uniquely laterally compressed abdomen, the identification of the new species is unmistakeable. Also, some of the structures of the female postabdomen are species-specific: S7 desclerotized, submembranous without distinct margins; genital chamber with 3 sclerotized structures (paired posterior sclerites, unpaired anterior sclerite and transverse annular sclerite between them); spermathecae elongately cylindrical with small terminal invagination and a collar surrounding duct insertion.
This distinctive species seems to be most closely allied to A. sulphurea sp. nov. described below. This relationship is supported by the construction of the annular sclerite in the female genital chamber (transverse, bent onto sides of chamber) that is unique among the known species of the genus Anthomyza, the similarly structured spermathecae (including the ringed surface, small terminal invagination and rim-like collar of duct opening) but also by the enlarged macrosetae of the head and thorax. As discussed below under A. sulphurea these two species probably represent a further lineage of Anthomyza which could be related to the A. bellatrix group. However, to demonstrate this sister-group relationship definitively, more morphological data (including male genital characters of A. ornata) are needed.
Etymology. The species is named for its unusually bicoloured thorax by a Latin adjective ornatus (- a, - um), meaning decorated.
Biology. The holotype was swept in June from lush vegetation (mainly consisting of dicotyledons but also with a smaller bamboo component; M. Tkoč, personal communication, 2018) forming the undergrowth of a montane (2570 m) leafy forest (Figs 84, 85).
Distribution. China: Sichuan.
description: Published as part of Roháček, Jindřich, 2018, First Anthomyzidae (Diptera) from China: a new genus, six new species and new records, pp. 35-76 in Acta Entomologica Musei Nationalis Pragae 58 (1) on pages 60-64, DOI: 10.2478/aemnp-2018-0007, http://zenodo.org/record/3676725