Amygdalops stenopteryx, ROHÁČEK J., 2008

ROHÁČEK J., 2008, Revision Of The Genus Amygdalops Lamb, 1914 (Diptera, Anthomyzidae) Of The Oriental, Australasian And Oceanian Regions, Acta Zoologica Academiae Scientiarum Hungaricae 54 (4), pp. 325-400 : 383-389

publication ID	https://doi.org/ 10.5281/zenodo.12584953
persistent identifier	https://treatment.plazi.org/id/A2710835-FF81-8C68-9B34-B1C2FC7AF8E3
treatment provided by	Felipe
scientific name	Amygdalops stenopteryx
status	sp. nov.

Treatment

Amygdalops stenopteryx View in CoL sp. n.

( Figs 149–160 View Figs 149–154 View Figs 155–160 , 174 View Figs 171–174 )

Type material: Holotype male, labelled: „ THAILAND, Bangkok, Pratomvan , Aug.-Sept. 1962, J. Scanlon-light ” ( USNM, intact) . Paratypes: THAILAND: same data as for holotype, 7 males 7 females; Bangkok, Plukchit, at light, viii-ix.1962, 1 male 2 females, J. Scanlon leg.; Bangkok, Thonglo, at light, viii-ix.1962, 1 male, J. Scanlon leg.; Bangkok, Makasan Dist. , at light, 11–12.v.1959, 1 male, Manop leg. ( USNM, 2 males 2 females with genit. prep.; 1 male 1 female in SMOC) .

Etymology – The species is named acccording to its strikingly narrowed wings.

Description – Male. Total body length 2.22–2.65 mm. Body bicolourous, dorsally dark brown, ventrally whitish yellow. Head elongate, subtriangular in dorsal outline, about 1.5 times as long as high, rectangular in profile anteriorly, with frons distinctly projecting in front of eye. Occiput strongly concave, brown with some parts darker or paler pigmented, except lateral areas sparsely greyish microtomentose. Frons very narrow and long, brown, medially in front of ocellar triangle depressed. Frontal triangle narrow, reaching to anterior third of frons, with strongly tapered anterior corner; its sides margined by blackish brown, dull and densely grey microtomentose stripes. Ocellar triangle paler to reddish brown, bare and shiny. Orbit wide, largely shining brown, but with a narrow (anteriorly widened), strikingly silvery white microtomentose, lateromarginal stripe. Face ochreous, dull; parafacialia (very narrowed) and gena yellowish white, with silvery white microtomentum; also postgena light yellow. Mouthparts pale yellow, palpus usually darker. Cephalic chaetotaxy: pvt minute but with apices meeting or crossed; vti very slightly shorter than vte, the latter and/or posterior ors longest of cephalic setae; oc weak, only half length and thickness of vte; 2 strong ors, posterior sometimes longer than vte, anterior also robust, as long as vti; 1 short setula and 1 (sometimes absent) microsetula in front of anterior ors; 2 pairs of microsetulae medially in front of frontal triangle; 1 vi and 1 shorter (at most two-thirds of vi) subvibrissa, both relatively weak; peristomal setulae (6–7) small and fine; palpus with 1 subapical seta as long as subvibrissa and 1 shorter ventrobasal seta. Eye strongly convex, of rounded tetragonal outline, with longest diameter 1.7 times as long as shortest one. Genal smallest height 0.08 times as long as shortest eye diameter. Antenna bicolourous, dark brown and whitish; scape, pedicel and dorsal (proximal) half to two-thirds of 1st flagellomere dark brown, only apical half or third of 1st flagellomere whitish and white ciliate on apex. Arista 1.6–1.7 times as long as antenna, long-pectinate, including 2–3 long rays ventrally.

Thorax narrower than head, with dorsal half dark brown and ventral half whitish yellow. Mesonotum and scutellum dark brown. Humeral and notopleural areas paler brown to ochreous and with denser whitish grey microtomentum. Pleural part of thorax with dark brown dorsal half (extending down to dorsal apex of fore coxa) including also postscutellum; ventral half of pleura yellowish white. Thoracic chaetotaxy: 1 small prs, hardly discernible from thoracic microsetae; 2 dc, posterior about as long as apical sc, anterior weak, less than one-third of posterior dc; 2 sc, apical long and strong, laterobasal as long as anterior dc; 2 stpl, both rather strong but posterior longer; a few dark additional setulae on sternopleuron ventral to stpl. Scutellum rounded triangular, slightly convex dorsally. Legs pale to whitish yellow (coxae). f 1 with 2 (or 3) very long setae in posteroventral row. t 2 with ventroapical seta rather robust. f 3 with posteroventral row of 7–8 short, slightly thickened, setae. Wing ( Fig. 174 View Figs 171–174 ) extremely narrowed, with modified pattern: apical dark spot extended over anterior half of wing length covering large area between R 4+5 and C. R 2+3 running very closely to C (almost touching it in its middle) and ending far from apex. R 4+5 and M convergent both basally and (yet more) apically; discal (dm) cell very narrow and r-m situated near its middle. Basal (and also apical) end of wing narrowed; alula and anal lobe strongly reduced. CuA 1 and A 1 not reaching wing margin; A 1 very shortened. Wing measurements: length 2.10–2.54 mm; width 0.47–0.56 mm, Cs 3: Cs 4 = 3.20–3.85, r-m\dm-cu: dm-cu = 3.33–4.44. Haltere brown, knob often darker.

Abdomen with all sclerites uniformly brown to dark brown. Preabdominal terga large, reaching far onto ventral side of abdomen. T1 shorter and less setose than following terga (T2-T5). T6 non-sclerotized, short, pale and bare. Preabdominal sterna brown, elongate, very narrow (S3 twice longer than wide) and finely setose, only S1 short, bare, wider than long and paler than others. S2-S5 becoming somewhat wider posteriorly, S5 the largest, widened and shallowly emarginate posteriorly. S6 short and transverse; S7 1.5 times as long as S6; both S6 and S7 with blackish brown anterior marginal stripe and each with 2 minute setulae. S8 long, more than twice longer than S7, shortly setose as are T2-T5.

Genitalia. Epandrium ( Figs 150–151 View Figs 149–154 ) moderate, not very wide but high and dorsally narrowed, with relatively short setae, only 1 dorsomedial pair long; anal opening small ( Fig. 150 View Figs 149–154 ). Cercus slender and about as long as gonostylus. Medandrium ( Fig. 150 View Figs 149–154 ) moderately sized, with protruding dorsolateral corners. Gonostylus ( Figs 150–151, 153 View Figs 149–154 ) unusually short, broad proximally, deagal complex, lateral view. Scales: Fig. 153 View Figs 149–154 = 0.05 mm, others = 0.1 mm

strongly narrowed distally, with subacute apex bent anteromedially (cf. Fig. 150 View Figs 149–154 ); its outer side with rich and dense micropubescence (except for anterior and posterior margins); inner side of gonostylus with several setae. Hypandrium ( Fig. 152 View Figs 149–154 ) simple, slender, with small unpigmented internal lobes; transandrium ( Fig. 149 View Figs 149–154 ) with arched dorsal medial ledge, but with straight ventral margin; caudal process arising on inner side of transandrium (cf. Fig. 152 View Figs 149–154 ), slender dorsally but formed by a pair of diverging pigmented stripes ventrally. Pregonite ( Fig. 152 View Figs 149–154 ) reduced, very low, incurved and hardly protruding ventrally, usually with 4 setae in one group. Postgonite ( Fig. 152 View Figs 149–154 ) slender, slightly sinuous, with pointed pale apex and 1 setula in proximal fourth to third of outer side; basal sclerite of postgonite small. Aedeagal part of folding apparatus ( Fig. 154 View Figs 149–154 ) narrowed and darkened dorsally, and externally provided with lenticular tubercles (larger ventrally). Connecting sclerite slender, long, sinuous; its membranous vicinity finely densely spinulose. Basal membrane with transverse short spines and with a small group of smaller spines posteromedially ( Figs 149, 152 View Figs 149–154 ). Aedeagal complex ( Fig. 154 View Figs 149–154 ) with robust phallapodeme, having widened, asymmetrical basal fork, robust but pale ventral fulcrum and longer apex with projecting corners. Phallophore short, dorsally with anterior process. Distiphallus voluminous, composed of largely membranous saccus and slender sclerotized filum. Saccus of distiphallus basally provided with slender ventral sclerites reaching to its middle, otherwise membranous and its armature formed by two types of spines – dense fine acute spines on apex and short drawing-pin like spines on anterodorsal surface. Filum of distiphallus ( Fig. 154 View Figs 149–154 ) long, curved, composed of 2 stripe-like closely attached sclerites (one darker and wider) terminating in slender membranous apex. Ejacapodeme not observed.

Female. Similar to male unless mentioned otherwise. Total body length 2.42–2.86 mm. f 3 posteroventrally lacking shortened setae. Wing measurements: length 2.34–2.78 mm, width 0.47–0.62 mm, Cs 3: Cs 4 = 3.12–3.86, r-m\dm-cu: dm-cu = 3.45–4.50. Abdomen. Preabdominal terga entirely dark brown, more transverse than in male, T3-T5 the widest. Preabdominal sterna pale brown (S1, S2) to brown (S3-S5); S1 short as in male; not only S2-S4 but also S5 elongate and very narrow, the latter very slightly wider than S4 (almost twice longer than wide) and markedly narrower than S6 (largest abdominal sternum).

Postabdomen ( Figs 156–157 View Figs 155–160 ) with all sclerites dark brown. T6 large, longer and broader than T7, dark brown except for pale posterior margin ( Fig. 156 View Figs 155–160 ), with short and thick setae. S6 brown with paler posterior margin, slightly longer than wide, sparsely setose (posterior setae longest). T7 narrow but wider than long, dark brown with posterior pale-pigmented margin. S7 ( Fig. 157 View Figs 155–160 ) narrower than S8, with distinctive pattern (anteromedially with small narrow unpigmented area, also its posterior part pale-pigmented) and with fine setae in posterior half. T8 small, brown, transversely trapezoidal, with sparse setae including long ones in posterior corners. S8 dark brown posteriorly and paler anteriorly, of usual shape but rather elongate. T10 small, brown, finely microtomentose in posterior half around a pair of medial setae. S10 wider and paler than T10, micropubescent except for anterior margin ( Fig. 158 View Figs 155–160 ). Internal sclerotization of genital chamber with 2 pairs of sclerites, larger anterior on lateral sides of chamber ( Fig. 159 View Figs 155–160 ), smaller posterior being fused posteromedially (cf. Fig. 158 View Figs 155–160 ) and with unusually small and narrow, bent in lateral view, annular sclerite ( Fig. 158 View Figs 155–160 ); vaginal area near genital opening simple. Ventral receptacle ( Fig. 155 View Figs 155–160 ) hyaline, membranous, elongately pouch-shaped with finely ringed base and ventrally directed terminal finger-like projection. Accessory gland hyaline, on ringed duct dilated distally. Spermathecae spherical ( Fig. 160 View Figs 155–160 ), with numerous short, blunt surface spines around duct insertion; duct cervix well developed, somewhat shorter than body of spermatheca. Cerci ( Fig. 156 View Figs 155–160 ) medium sized, brown, with rich but fine setae.

Discussion – A. stenopteryx sp. n. is a peculiar species differing from all known congeners by the most elongate and dorsally flattened head and strikingly narrowed wings with modified venation and dark pattern (see Fig. 174 View Figs 171–174 ). Two of these characters (11C and 17 in Fig. 175 View Fig ) are shared with A. sp. n. (d) and are considered synapomorphic for these two species forming together the A. stenopteryx group. A. stenopteryx sp. n. is the more modified of this pair and differs from A. sp. n. (d) by the markedly narrow wing having a larger dark area, its orbit with a lateroothers = 0.05 mm

datus, female (Taiwan), length 2.8 mm, 166 = A. curtisi sp. n., male paratype (Taiwan), length 2.3 mm

marginal silvery stripe, its longer vti and preabdominal sterna elongate and brown, not to mention its distinctive male genitalia (dorsally narrowed epandrium, short gonostylus, armature of saccus of distiphallus) and its female postabdomen (elongate S6, S7 and S8, small annular sclerite and distinctive internal sclerites). Interestingly, the anterior marginal dark area on the wing of both species of the A. stenopteryx group somewhat resembles those of Margdalops species (see ROHÁČEK & BARRACLOUGH 2003: Figs 66–71 View Figs 64–71 ) but it surely evolved independently in these Amygdalops species by secondary expansion of the preapical dark spot into cells r 1 and (in A. stenopteryx sp. n.) r 2+3.

Biology – All available specimens were collected at light, in V, VIII–IX.

Distribution – Thailand.

Lanka), length = 2.5 mm