Anthomyza aspina, Roháček, 2021

Roháček, Jindřich, 2021, New species and records of Anthomyzidae (Diptera) from the East Palaearctic, with a checklist of taxa occurring in the area, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1), pp. 261-288 : 263-268

Anthomyza aspina sp. nov.

( Figs 1–16 )

Type material. Hඈඅඈඍඒඉൾ: ♀, labelled: ‘Юж. Приморье’ (printed), ‘Каменушка 23. VI 1984 ’ [= Yuzh. Primor’e, Kamenushka] (Indian ink handwriting),‘А. Шаталкин’ [= A. Shatalkin] (printed), ‘ Anthomyza sp. , det. D. Gavryushin, 2008’ and ‘ Holotypus ♀, Anthomyza aspina sp. n., J. Roháček det. 2020’ (red label) ( ZMUM, genit. prep.). Pൺඋൺඍඒඉൾ: ♀, with same data but with ‘Каменушка 25. VI 1984 ’ (Indian ink handwriting) on locality label and with ‘ Anthomyza bellatrix Roháček , det. D. Gavryushin, 2008’ and ‘ Paratypus ♀, Anthomyza aspina sp. n., J. Roháček det. 2020’ (yellow label) ( SMOC, genit. prep.). Note. The type locality actually lies close to selo (= village) Kaimanovka (which was formerly a part of Kamenushka), 43°37ʹ52ʺN 132°13ʹ46ʺ E, near the Barsukovka river (A. Shatalkin, personal communication, 2021).

Description. Male unknown.

Female. Total body length 2.78 mm (holotype) to 2.94 mm (paratype); generally brown to dark brown ( Fig. 3 ), with head largely yellow, thorax dull and densely lightgrey microtomentose but abdomen subshining, with sparse microtomentum. Head yellow to (anteroventrally) whitish yellow ( Figs 1, 4, 5 ), except for occiput and ocellar triangle (both brown to dark brown), very slightly higher than long, in profile almost rounded anteriorly (frons not projecting in front of eye). Occiput dorsomedially concave, brown to (laterally) dark brown, only small dorsal area behind ocellar triangle dark yellow to ochreous and ventralmost parts pale brown, all subshining due to sparse greyish microtomentum. Frons ( Figs 1, 4 ) bright yellow, orange at anterior margin, with only frontal triangle brown (ocellar triangle dark brown), the latter pale grey microtomentose and dull. Orbital plate yellow or somewhat darkened posteriorly, entirely (up to vte) silvery-whitish microtomentose and dull. Frontal triangle relatively small, equilateral, reaching only a little into front half of frons, pale brown with anterior corner ochreous; ocellar triangle convex, dark and covering most of frontal triangle; ocelli relatively large ( Fig. 4 ). Frontal lunule small, transverse, yellow and whitish microtomentose. Face relatively narrow, less sclerotized and somewhat concave, white to dirty yellow ventrally and whitish microtomentose; parafacialia and gena whitish, with dense silvery-white microtomentum, both bordered by very narrow, yellowish-white to pale ochreous marginal stripe; postgena whitish yellow to dirty yellow, also densely whitish microtomentose and hence sharply delimited from adjacent shiny ochreous to brown ventrolateral part of occiput. Mouthparts dirty yellow to orange ochreous (darkest distally), with pale yellow clypeus and yellowish-white palpus. Cephalic chaetotaxy: all macrosetae relatively long (see Fig. 5 ) but fine, hence not as strong as those of Anthomyza ornata Roháček, 2018 ; pvt relatively long and very strongly crossed ( Fig. 4 ); vti longest of cephalic setae; oc slightly divergent, almost as long as vti and slightly longer than vte; 3 ors of distinctive size combination with middle ors longest ( Fig. 5 ), markedly longer than both posterior and anterior ors, the latter two subequal, thus anterior ors also unusually long (see Figs 1, 5 ); 1 microsetula (about as long as medial microsetulae) in front of anterior ors; 2 or 3 pairs of medial microsetulae between apex of frontal triangle and anterior margin of frons; 1 small and pale inclinate setula behind vte; postocular setulae (7 or 8) also small and pale, in single row; lateroventral part of occiput and postgena with several pale setulae, with 1 longer but fine seta in posteroventral corner; 1 weak vi (as long as but finer than anterior ors); subvibrissa not developed (indistinguishable from peristomals); peristomal setulae (5 or 6) also small, fine and sparse. Palpus small and slender, with 1 longer and blackish preapical seta and about 5 pale ventral and lateral microsetulae; labella fleshy, orange, broad and very finely long setulose. Eye not very large, somewhat smaller than that of A. ornata , broadly subreniform ( Fig. 3 ), with longest diameter oblique and about 1.3 times as long as the shortest. Gena distinctly higher than in A. ornata (see Fig. 5 ), with shortest height 0.20 times shortest eye diameter. Postgena also relatively large ( Fig. 3 ). Antenna yellow, only 1st flagellomere more or less orange ochreous, darkened around insertion of arista; pedicel with dorsal seta small and weak; 1st flagellomere suboval, laterally strongly flattened and with relatively short white cilia on anteroventral margin. Arista dark brown including thickened basal segment, only 1.7 times as long as antenna, with brownish cilia hardly longer than those on 1st flagellomere.

Thorax as wide as head, brown to dark brown in ground colour but very densely pale grey microtomentose (often with some bluish tinge) and dull ( Figs 1, 5 ); microtomentum on pleural part of thorax less dense but also distinct. Mesonotum dark brown to brown except area between supraalar seta and wing base pale brown; small spot at base of posterior notopleural seta ochreous to yellow, as is also apical margin of scutellum with areas surrounding bases of apical scutellar setae lightest. Pleuron ( Fig. 5 ) lighter brown than mesonotum, sutures between sclerites ochreous and ventral corner of sternopleuron becoming yellow on apex. Prosternum and mesosternum ochreous to yellow. Postscutellum bulging and blackish brown ( Fig. 3 ). Thoracic chaetotaxy rich, with macrosetae long but relatively fine: 1 hu (distinctly shorter and finer than anterior npl); 2 npl (posterior short, slightly shorter than hu); 1 long prs and 1 subequally long sa; 1 pa (distinctly shorter and thinner than sa); 2 postsutural dc but 1 of microsetae in front of them may also be enlarged (more distinctly in holotype), posterior dc very long (longest thoracic seta), anterior dc fine and only about half length of posterior dc; 6 or 7 dc microsetae in front of them (1 dc microseta can also be present between anterior and posterior dc); 4 rows of ac microsetae on suture, 2 rows more posteriorly; hindmost ac pair (situated slightly in front of posterior dc) distinctly enlarged, in holotype almost forming ac macroseta (as long as hu); 2 sc, laterobasal fine and as long as anterior dc, apical strong and very long, almost as long as posterior dc; 1 distinct but fine and pale upcurved ppl (reaching to about half of propleuron); 2 stpl, both thin, anterior only half length of posterior; 1 pale setula in front of anterior stpl and 2 or 3 setulae below it; ventral corner of sternopleuron with only 2 or 3 longer but pale and fine setae. Scutellum rounded triangular ( Fig. 1 ), relatively long (ca 1.4 times as wide as long), convex dorsally.

Legs uniformly yellow to yellowish white ( Figs 2, 3 ), tibiae and tarsi darker than femora, trochanters and coxae (these palest), only apices of last tarsal segments somewhat darkened, ochreous. f 1 ( Fig. 2 ) with posterodorsal and posteroventral rows of unusually pale and long setae but ctenidial spine entirely absent; f 2 and f 3 simply uniformly setulose, as are also all tibiae, except for t 2 having a distinct, dark but very short (as long as tibial width) ventroapical seta and 3 small dark anteroventral setulae on apex; only fore basitarsus with proximoventral fine and pale setulae slightly longer than others.

Wing ( Fig. 3 ) long and relatively narrow, 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, bent parallel to C but apically shortly and slightly upcurved to it, running closely to C and producing cell r 1 very narrow, only half width of cell r 2+3 (thus markedly different from that of A. ornata , A. sulphurea Roháček, 2018 or A. breviclavus sp. nov.); R 4+5 slightly bent along almost entire length, running nearly parallel to R 2+3 but with distal part almost straight. M (beyond dm-cu) very slightly bent to almost straight basally, subparallel to R 4+5 distally. Cell dm relatively large and long, with r-m situated at basal two-fifths (holotype) to half (paratype) of cell. Apical portion of CuA 1 short, 1.1–1.4 times as long as dm-cu and not reaching wing margin; A 1 short, ending far from wing margin. Alula relatively large but narrowed and with apex rounded; anal lobe well developed. Wing measurements: length 3.02 (holotype) to 3.08 (paratype) mm, width 1.07 (holotype) to 1.15 (paratype) mm, Cs 3: Cs 4 = 1.06 (holotype) to 1.18 (paratype), rm\dm-cu: dmcu = 2.03 (paratype) to 2.41 (holotype). Haltere ( Fig. 3 ) yellow to pale ochreous, with darker orange-ochreous base of stem.

Abdomen dorsally dark brown, ventrally brown to ochreous-yellow, sparsely microtomentose and subshining to almost shining ( Fig. 3 ). Preabdominal terga brown, all with very sparse microtomentum and relatively short and sparse setae. T1 and T2 only laterally fused, dorsally distinctly separate; T1 shorter and narrower than T2; T2–T5 subequal in length or T5 slightly longer, transverse and bent far onto lateral sides of abdomen, T2–T4 subequal in width but T5 ( Fig. 6 ) narrower than T4. Preabdominal sterna ochreous-yellow to brown, all shortly, finely and sparsely setose. S1 short (about half length of S2), transverse, somewhat wider than S2, pale ochreous brown; S2–S5 subequal in length but becoming somewhat wider posteriorly (S5 widest); S2 longer than broad, brown, with basal dark stripe separated from rest of sclerite by yellowish-white area; S3–S5 pale ochreous or S3 and S5 anteriorly darkened, S3 as long as broad, S4 slightly and S5 distinctly wider than long ( Fig. 7 ).

Postabdomen ( Figs 6–8 ) medium long, tapered from 7th segment. T6 broad but somewhat narrower, shorter and darker than T5, with setae in posterior two-thirds, those at posterior margin longest. S6 ( Fig. 7 ) wider, more transverse and darker brown (mainly laterally and posteriorly) than S5, finely setose in posterior half. T7+S7 fused to form compact, conical, strongly sclerotized ring-shaped synsclerite (tergosternum) that is dorsally and laterally uniformly blackish brown ( Figs 6, 8 ) but ventrally with pale-pigmented anterior marginal stripe ( Fig. 7 ); tergosternum T7+S7 setose mainly in posterior half and 7th spiracle embedded lateroventrally, near anterior margin of synsclerite ( Figs 7, 8 ). T8 narrow, elongate, flat ( Figs 6 , 16 ), slightly tapered posteriorly, pale pigmented, bare except for some short and fine setae and 1 long seta in posterolateral corner. S8 shorter and much wider than T8, medially divided into 2 dark-pigmented sclerites ( Fig. 7 ), each posterodorsally somewhat invaginated (cf. Figs 8 , 10 ); external side of S8 finely setose (with 1 seta long) and micropubescent (as is usual in Anthomyza ). Genital chamber relatively short and broad ( Figs 10, 13 ) without paired internal sclerites (or these membranous), only annular sclerite distinctly developed and (for Anthomyza ) unusually compressed ( Figs 10, 13 ) and bent onto lateral surfaces of genital chamber (as in A. sulphurea or A. ornata ). Ventral receptacle ( Figs 10–12 ) relatively subtle, membranous, elongately tubiform, with basal part wider and twisted several times, distal part slender and straight, ending in a hook-like, slightly sclerotized apex. Remnant of accessory gland small, grape-like, on very slender duct that is somewhat dilated but plain in the middle ( Fig. 10 ). Spermathecae (1+1) subovoid ( Fig. 9 ) to broadly oval ( Fig. 14 ), each with sparsely (often asymmetrically) ringed distal part, simple apex without terminal invagination, eccentrically inserted duct (without sclerotized cervix or collar), and several short spinulae proximally near duct insertion; spermathecal duct very long (about as long as abdomen) and all membranous. T10 very small, transversely hexagonal to oval, pale pigmented ( Figs 6 , 16 ), with single medial pair of long setae (as long as those on cercus) in middle of posterior margin, and some sparse micropubescence near them. S10 ( Fig. 15 ) much larger than T10 but largely hidden under S 8 in ventral view ( Fig. 7 ), longer than wide, rounded pentagonal, finely setulose (marginally in posterior half) and densely micropubescent. Cercus of moderate size, relatively slender, with rich setosity, apical and dorsopreapical setae sinuate and much longer than other long setae of cercus ( Figs 10, 15 ).

Discussion. Anthomyza aspina sp. nov. is the first species of the genus Anthomyza found to be lacking a ctenidial spine on the fore femur. Apart from this atypical feature, it is also characterized by the middle ors markedly longer than both anterior and posterior ors (also very unusual), the almost entirely yellow head combined with dark brown but densely pale grey microtomentose thorax and dark, relatively shining abdominal terga. The female postabdominal sclerites (particularly the large and dark annular tergosternum T7+S7, see Fig. 3 ) and structures of the female genital chamber are also very characteristic. The reduced internal sclerotization (paired sclerites membranous or absent) and the compressed annular sclerite bent onto the lateral walls of the genital chamber (and also the elongate S10) indicate a relationship of A. aspina with the two Chinese species, A. ornata and A. sulphurea (see RඈIJගඹൾκ 2018: figs 93, 95, 114, 116), and also with A. breviclavus sp. nov. ( Figs 26, 28 ) from North Korea described below. However, A. aspina differs distinctly from all these species by the detailed construction of the annular sclerite (most strongly compressed among all known Anthomyza spp. ), shape and surface of the spermathecae and form of the ventral receptacle not to mention the dark and completely fused T7+S7 and wing with unusually narrow cell r 1. It should be noted that both above Chinese species have the ctenidial spine strongly reduced (extremely short in A. sulphurea , see RඈIJගඹൾκ 2018: fig. 111) so that its entire disappearance in A. aspina may not be so surprising.

Etymology. The name ‘ aspina ’ refers to the absence of a ctenidial spine on the fore femur. It is a Latin noun, in the nominative singular in apposition, meaning without spine.

Biology. Unknown. The holotype and paratype females were collected in June. Both specimens were netted by A. Shatalkin (personal communication, 2021) from rich low vegetation in open damp places in taiga forest close to the Barsukovka river. Several other species of Anthomyzidae were also collected in this locality, including Epischnomyia triarmigera ( Sueyoshi & Roháček, 2003) , Stiphrosoma fissum Roháček, 1996 (see records below), Anthomyza elbergi Andersson, 1976 and even the extremely rare Ischnomyia barbarista ( Roháček, 2009) (for their records see RඈIJගඹൾκ 2009).

Distribution. Russia: Far East (Primor’e).

Figures

Figs 1–5. Anthomyza aspina sp. nov., female. 1 – head and thorax, subdorsally, holotype (body length 2.78 mm); 2 – fore legs, anteriorly and posteriorly, paratype; 3 – female before dissection, paratype (body length 2.94 mm); 4 – head, dorsally, holotype; 5 – head and thorax, laterally, holotype. Photos by J. Roháček.

Figs 6–9. Anthomyza aspina sp. nov., female holotype. 6 – postabdomen + 5th abdominal segment, dorsally; 7 – the same, ventrally; 8 – postabdomen, laterally; 9 – spermathecae, largest extension view. Scales = 0.2 mm (Figs 6–8) and 0.05 mm (Fig. 9). For abbreviations see p. 263.

Figs 10–16. Anthomyza aspina sp. nov., female. 10 – genital chamber with 8th and 10th abdominal segments, laterally; 11 – ventral receptacle, laterally; 12 – the same, ventrally; 13 – genital chamber (without appendages), ventrally; 14 – spermathecae (all based on paratype); 15 – S10 and cerci, ventrally; 16 – T8 and T10, dorsally (both based on holotype).Scales = 0.1 mm (Figs 10, 13, 15, 16) and 0.05 mm (Figs 11, 12, 14). For abbreviations see see p. 263.

Figs 26–28.Anthomyza breviclavus sp. nov., female holotype.26 – genital chamber with 8th abdominal segment,laterally; 27 – ventral receptacle, proximal (above) and distal (bottom) part, largest extension view; 28 – genital chamber with S8, ventrally.All scales = 0.1 mm. For abbreviations see see p. 263.