Anthomyza breviclavus, 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 : 268-273

Anthomyza breviclavus sp. nov.

( Figs 17–31 )

Type material. Hඈඅඈඍඒඉൾ: ♀, labelled:‘D. P.R. KOREA, PAEKDUSAN Mts., SANJIYON, lgt. M. KOZÁNEK’ (obverse, printed), ‘18. 8. 89’ (reverse, pencil handwriting) and ‘ Holotypus ♀, Anthomyza breviclavus sp. n., J. Roháček det. 2020’ (red label) ( SMOC, genit. prep.).

Description. Male unknown.

Female. Total body length 2.54 mm; bicolourous but largely yellow (pale yellow to pale ochreous) with only longitudinal vittae on thorax brown ( Figs 17, 19 ), rather sparsely whitish microtomentose, subshining, with wings distinctively variegated. Head pale yellow except for a small brown spot on ocellar triangle ( Fig. 19 ), somewhat higher than long, in profile almost rounded anteriorly (frons not projecting in front of eye). Occiput dorsomedially concave, entirely yellow (lighter medially) and subshining, but with a patch of silvery-white microtomentum at dorsal margin of foramen. Frons bright to pale yellow, with only central spot on ocellar triangle brown, largely dull, only margins of frontal triangle and orbital plate somewhat glittering. Entire orbital plate light yellow, sparsely silvery-whitish microtomentose and slightly glittering. Frontal triangle relatively narrow, somewhat longer than broad, reaching anterior two-fifths of frons, concolourous with adjacent frons but delimited by narrowly golden glittering margins and whitish microtomentose posterior corners; ocellar triangle somewhat elevated, having marginal parts yellow and central area between (medium-sized) ocelli brown. Frontal lunule very small, yellow, with whitish microtomentum. Face narrow, concavely depressed, white and whitish microtomentose; parafacialia and gena also white, with silvery-white microtomentum, both bordered by a very narrow marginal stripe that is darker (yellow) on ventral margin of gena; postgena white to whitish yellow posteriorly, sparsely whitish microtomentose, confluent with similarly coloured ventrolateral part of occiput; mouthparts yellow including clypeus and palpus. Cephalic chaetotaxy: all macrosetae (see Fig. 17 ) dark, long but relatively thin and most similar to those of A. ornata (see below); pvt unusually long (right pvt seta two-thirds of vti!) and strongly crossed; vti very long, longest of cephalic setae; oc subparallel (unnaturally erect in holotype, see Fig. 17 ) and almost as long as vti; 3 ors, posterior and middle obviously long and strong (both broken in holotype), anterior markedly shorter and fine, only about a quarter length of vti; 1 microsetula (as long as medial microsetulae) in front of anterior ors; 3 or 4 pairs of medial microsetulae between apex of frontal triangle and anterior margin of frons; 1 inclinate setula (as long as uppermost postocular) behind vte; 7 or 8 postocular setulae, all relatively short but dark, in single row; lateroventral part of occiput and postgena with a few dark setulae, 1 longer but fine seta in posteroventral corner; 1 vi (undoubtedly shorter and weaker than both long ors); subvibrissa apparently absent; 5 or 6 small peristomal setulae becoming longer anteriorly. Palpus slender and rather long, with 1 relatively long and dark preapical seta and a few (3–5, all dark) setulae; labella fleshy, dirty yellowish white, finely long setulose. Eye relatively small (as in A. sulphurea ), elongately reniform ( Fig. 17 ), with longest diameter oblique and about 1.4 times as long as the shortest. Gena higher than in A. ornata , resembling more that of A. sulphurea , with shortest height 0.30 times shortest eye diameter. Antenna yellow (scape, pedicel) to whitish yellow (1st flagellomere); pedicel with dorsal seta normal; 1st flagellomere elongately suboval, laterally flattened and with relatively long white cilia on anteroventral margin (as in A. ornata ). Arista brown including thickened basal segment, about 1.8 times as long as antenna, with pale cilia slightly shorter than those on 1st flagellomere.

Thorax distinctly wider than head, largely yellow but brown striped (thoracic pattern most resembling that of A. ornata and Epischnomyia spp. ), finely whitish microtomentose, almost dull. Mesonotum yellow, with broad brown vittae between dc and prs-sa lines that are not fused anteriorly (thus, in contrast to A. ornata , medial yellow area reaching anterior margin of mesonotum) and posteriorly continuing narrowly on sides of otherwise yellow scutellum. Humeral and notopleural areas whitish yellow. Pleuron whitish yellow but dorsally with brown band reaching from propleuron to base of abdomen (see Figs 17, 19 ); ventral part of pleuron yellowish white. Postscutellum bulging ( Fig. 17 ) and dark ochreous. Thoracic chaetotaxy rich, with most macrosetae very long (as in A. ornata ) and dark: 1 hu (slightly shorter and finer than anterior npl); 2 npl (posterior shorter); 1 exceptionally long prs ( Fig. 17 ) and 1 subequally long or slightly longer and thicker sa; 1 pa (somewhat shorter and thinner than sa); 2 postsutural dc: posterior extremely long and robust (longest thoracic seta), anterior also long but only about half length of posterior dc; only 4 or 5 dc microsetae in front of them (no dc microseta between anterior and posterior dc); ac microsetae sparse but relatively long, in only 2 rows on suture; hindmost ac pair (situated between posterior dc) only slightly longer than others; 2 sc (all are broken off); judging from basal remnants apical sc must be strong and very long and laterobasal sc small (situated unsually laterally in middle of scutellar side); 1 relatively long but very fine upcurved ppl; 2 stpl, posterior long, anterior distinctly shorter ( Fig. 17 ); 1 setula in front of anterior stpl and 1 other between both stpl, and 5 or 6 setulae below it; ventral corner of sternopleuron with 5 or 6 fine setae, 3 or 4 of them longer. Scutellum rounded triangular, very slightly convex to flat dorsally, about 1.6 times as wide as long.

Legs yellow to yellowish white (coxae lightest), only apical half of last tarsal segment of all legs darkened, brown ( Fig. 19 ). f 1 ( Fig. 29 ) with usual posterodorsal and posteroventral rows of dark long setae and robust ctenidial spine (in contrast to A. ornata ) that is slightly longer than maximum width of t 1. f 2 and f 3 simply uniformly setulose, as are all tibiae, except for t 2 having a distinct but short (only as long as width of t 2) ventroapical seta and a pair of anteroventral setulae on apex ( Fig. 30 ); fore basitarsus with 2 enlarged but pale proximoventral setulae ( Fig. 29 ), mid basitarsus with single dark enlarged proximoventral setula ( Fig. 30 ) and hind basitarsus with 2 or 3 dark and robust proximoventral setulae ( Fig. 31 ).

Wing ( Fig. 18 ) relatively long and narrow, with whitish yellow (C, R 1, R 2+3) to brown veins (most parts of others). With distinctive pattern, composed of white hyaline marginal areas (on anterior, apical and posterior margin) and broad brown stripe in the middle covering area primarily between R 4+5 and CuA 1 but (in contrast to all known Anthomyzidae with similar wing patterning) not reaching to apex of wing. C with very distinct spinelike setae between apices of R 1 and R 2+3. R 2+3 not very long (ending far from wing apex), very slightly sinuous, subparallel to C but apically upcurved to it; R 4+5 slightly downcurved, basally running nearly parallel to C and distally to M. M (beyond dm-cu) basally almost straight and distally slightly downcurved. Cell dm long but relatively narrow, with r-m situated at basal two-fifths of cell. Apical portion of CuA 1 short, 1.15 times as long as dm-cu and not reaching wing margin; A 1 short, ending far from wing margin. Alula moderate, relatively narrow and with apex rounded; anal lobe well developed. Wing measurements: length 2.70 mm, width 0.95 mm, Cs 3: Cs 4 = 2.13, rm\dm-cu: dm-cu = 2.92. Haltere whitish yellow, with knob dirty yellow.

Abdomen generally yellow to pale brown ( Fig. 19 ). Preabdominal terga ( Fig. 20 ) largely yellow but T2–T5 with pale brown spot medially, all sparsely greyish microtomentose and subshining. T1 and T2 not distinctly separated, apparently fused dorsally; T1 slightly shorter and narrower than T2 and with small short setulae on disc; T2 slightly shorter than T3, sparsely setose in posterior half. T3–T5 subequal in length, transverse and bent far onto lateral sides of abdomen, all with relatively short and fine setae on disc and longer setae at posterior margin. Preabdominal sterna whitish yellow, relatively large and broad (pleural membranous part of preabdomen rather narrow). S2–S5 becoming very slightly wider posteriorly (S5 widest), all wider than long, S5 most transverse. S1 not observed; S2– S5 with fine and relatively sparse setae, those at posterior margin longest.

Postabdomen ( Figs 22–24 ) medium long, tapered from 7th segment. T6 large, only slightly narrower than T5, posteromedially pale brown to brown, anterolaterally yellow ( Figs 20, 23 ), bent onto lateral sides of segment as in preabdominal terga (see Fig. 22 ), setose in posterior two-thirds, and with setae at posterior margin long but fine. S6 ( Fig. 24 ) slightly wider than S5, transverse and similarly whitish yellow, with long setae posteriorly besides shorter setosity on disc. T7 and S7 separate. T7 brown (much darker than T6) in the middle ( Fig. 23 ), with unpigmented stripe at posterior margin and its anterior part pale brown. T7 tapered posteriorly ( Figs 20, 23 ), with sides extended far onto ventral aspect of 7th segment and embedding 7th spiracles ( Figs 22, 24 ), with more numerous setae than T6, including long ones at posterior margin. S7 ( Fig. 24 ) markedly narrower than S6, as long as broad, very slightly tapered posteriorly, yellowish white, with sides overlapping ventrolateral margins of T7, with distinct micropubescence and relatively long setosity, with 4 (2 pairs of) setae at posterior margin particularly long (see Fig. 24 ). T8 relatively small and flat, roughly square-shaped ( Fig. 23 ), pale pigmented, entirely micropubescent, and with fine setae in posterior half, only 1 of them (in posterolateral corner) long. S8 ( Figs 24 , 26, 28 ) about as long as or slightly longer than T8, medially very narrowly divided longitudinally into 2 distinctly pigmented sclerites that are somewhat bent dorsally and invaginated posteriorly (cf. Fig. 22 ); external surface of each side of S8 finely setose (with 3 longer setae) and micropubescent (as is usual in Anthomyza ). Genital chamber of medium length but relatively broad and somewhat asymmetrical ( Figs 26, 28 ), with reduced internal sclerotizations: only annular sclerite well developed, large, broad, transverse and bent onto lateral surfaces of genital chamber (as in A. ornata ); no posterior pair(s) of sclerites, only an asymmetrical submembranous structure lateroventral to annular sclerite; anterior part of genital chamber asymmetrical, with a pair of dark-pigmented groups of short blunt spine-like excrescences ( Figs 26, 28 ) ventrolaterally.Ventral receptacle ( Figs 26–28 ) medium long but tube-like and twisted, membranous, composed of larger and wider part having surface proximally toothed ( Fig. 27 ), medially plain and more distally somewhat bumpy, and of slender vermicularly twisted terminal part ( Fig. 27 ) with blunt apex. Remnant of accessory gland small, on somewhat dilated duct that is distally plain and gradually narrowed and ringed in the middle ( Fig. 26 ). Spermathecae (1+1) broadly oval to spherical ( Figs 21, 25 ), with simple apex without invagination, surface finely densely transversely ringed except for basal fourth or third and with a number of small spinulae proximally near duct insertion; no sclerotized cervix developed; spermathecal duct entirely membranous, simple and very long. T10 small, short, transversely suboblong, pale pigmented ( Fig. 23 ), with single medial pair of long setae (somewhat longer than those on cercus) in centre and some sparse and fine micropubescence. S10 ( Fig. 24 ) much larger and particularly longer than T10, somewhat longer than wide, finely setulose and densely micropubescent in posterior half but its posterior marginal area bare and rounded. Cercus of moderate size, rather wide but somewhat dorsoventrally flattened (cf. Figs 22, 23 ), with rich but not very long setosity, apical, subapical and dorsopreapical setae longest and more or less sinuate.

Discussion. Anthomyza breviclavus sp. nov. is easily recognized by its patterned wing which is broadly white margined, thus having its middle longitudinal dark stripe abbreviated, not reaching the apex of the wing ( Fig. 18 ).A similar longitudinal pattern is very rare in the genus Anthomyza , otherwise known only in A. caesarea Roháček, 2020 from Taiwan (cf. RඈIJගඹൾκ 2020: fig. 24). However, it also occurs in all three E. Asian species of the genus Epischnomyia (see Fig. 51 ) and the Nearctic Ischnomyia albicosta (Walker, 1849) and Arganthomyza vittipennis (Walker, 1857) (RඈIJගඹൾκ & Bൺඋൻൾඋ 2016: fig. 49 and fig. 85 respectively). However, in all these taxa the middle dark band is extended to the wing tip where it is dilated. Anthomyza breviclavus also differs from all these species by the largely yellow body. Judging from the long macrosetae of the head and thorax, the postabdominal structures and female internal genitalia, A. ornata and A. sulphurea (both from China, see RඈIJගඹൾκ 2018) are undoubtedly the closest relatives of this new species. The shape of the annular sclerite, the reduced internal sclerotization of the female genital chamber and the densely ringed spermathecae with a spinose basal part support this relationship. However, A. breviclavus differs from both these species (besides the strong ctenidial spine on f 1, and the colouration of head, thorax and wing) by the formation, pigmentation and setosity of T7, S7, T8, T10, S10, the subspherical spermathecae without a terminal invagination, the shape of the ventral receptacle as well as by the two groups of ventrolateral dark-pigmented blunt spine-like excrescences in the distal part of the female genital chamber (see Fig. 28 ). A similar armature is also known in some other (distantly related) species of Anthomyza , e.g. A. pengellyi Roháček & Barber, 2016 , A. concolor (Thomson, 1869) , A. variegata (Loew, 1864) (cf. RඈIJගඹൾκ & Bൺඋൻൾඋ 2016: figs 273, 335, 397) and A. orineglecta Roháček, 2006 (cf. RඈIJගඹൾκ 2009: fig. 42) so that this secondary sclerotization apparently evolved independently several times in various lineages of the genus. As mentioned above, A. aspina sp. nov. could also be related to A. breviclavus but certainly less distinctly than are A. ornata and A. sulphurea .

Etymology. The species is named for its distinctive wing pattern using a Latin noun in the nominative singular in apposition composed of brevis (= short) and clavus (meaning a coloured stripe on toga of ancient Roman senators).

Biology. Unknown. The holotype was swept in the Paekdusan Mts from low vegetation in August (M. Kozánek, personal communication, 2018).

Distribution. North Korea.

Figures

Figs 17–19. Anthomyza breviclavus sp. nov., female holotype. 17 – head and thorax, laterally; 18 – right wing (length 2.70 mm); 19 – female before dissection, sublaterally (body length 2.54 mm). Photos by J. Roháček.

Figs 20–25. Anthomyza breviclavus sp. nov., female holotype. 20 – entire abdomen, dorsally; 21 – spermatheca; 22 – postabdomen, laterally; 23 – the same, dorsally; 24 – the same, ventrally; 25 – spermatheca. Scales = 0.2 mm (Figs 20, 22–24) and 0.05 mm (Figs 21, 25).

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.

Figs 29–35. Legs and their parts of Anthomyzidae. 29–31 – Anthomyza breviclavus sp. nov., female holotype: 29 – left f1, t1 and fore basitarsus posteriorly (chaetotaxy partly reconstructed); 30 – distal end of right t2 and mid basitarsus, anteriorly; 31 – apex of left t3 and hind basitarsus, anteriorly; 32–34 – Zealantha fasciolata sp. nov., female holotype: 32 – left f1, t1 and fore basitarsus, posteriorly; 33 – left f2 and t2, anteriorly; 34 – right f3 and t3 posteriorly; 35 – Fungomyza cercata Roháček, left f3, t3 and hind basitarsus, anteriorly. All scales = 0.5 mm. For abbreviations see see p. 263.

Figs 49–55.Some E. Palaearctic Anthomyzidae.49 – Anthomyza clara Roháček, 2006, male, laterally (Japan), body length 2.22 mm; 50 – same specimen, head and thorax, dorsolaterally; 51 – Epischnomyia merzi Roháček, 2009, male, laterally (South Korea), body length 2.58 mm; 52 – same specimen, head and thorax, dorsally; 53 – Stiphrosoma fissum Roháček, 1996, male, laterally (South Korea), body length 1.79 mm; 54 – same species, female, laterally (South Korea), body length 1.85 mm; 55 – Stiphrosoma humerale Roháček & Barber, 2005, male, laterally (Far East of Russia), body length 1.90 mm. Photos by J. Roháček.