Minilimosina (Svarciella) tapiehella Su

Su, Lixin, Liu, Guangchun & Xu, Jie, 2015, A review of Minilimosina Roháček (Diptera: Sphaeroceridae) from China, Zootaxa 4007 (1), pp. 1-28 : 22-25

Minilimosina (Svarciella) tapiehella Su sp. nov.

( Figs. 92–100 )

Diagnosis. General colour shining black; antennae yellow but dorsoapical third of first flagellomere dark brown; legs yellow except for fore tibia and fore tarsomeres 1–4 ( Fig. 92 ) and mid coxa brownish black or black. One orbital seta. Male: tergites 3–5 and sternites 1–4 much paler but slightly sclerotized, tergite 5 divided into 2 parts; deflexed posteromedial lobe of sternite 5 ( Fig. 97 ) bearing a row of 6 short and thick setae and 4 long spine-like setae in front of it; cerci reduced; gonostylus ( Figs. 93, 94, 95 ): outer lobe with dorsal flattened process, inner lobe with anterior projecting lobe bearing 2 groups of short setae; distiphallus ( Fig. 96 ) with long whip-like apically bifurcate dorsal and T-shaped ventral sclerite. Sternite 8 of female ( Fig. 99 ) with large and blunt anteromedial convex expansion; sternite 10 ( Fig. 99 ) wide and short, anteriorly concave, with anterior sixth bare and posterior five-sixths setulose, having 2 long and 6 short setae on posterior margin; spermathecae ( Fig. 100 ) with basal tubercles.

Description. Body length 1.3 mm, wing length 1.2 mm. General colour shining black; including head, face, gena and lunule; antennae yellow but dorsoapical corner of first flagellomere dark brown, arista dark brown; haltere entirely white. Legs yellow except for fore tibia, fore tarsomeres 1–4 ( Fig. 92 ) and mid coxa brownish black or black. Abdomen with tergites 3–4 and sternites 1–4 much pale and little sclerotized, syntergite 1+2 and postabdomen black and strongly sclerotized, tergites 3–5 reduced, tergite 5 divided into 2 sclerites.

Head: One orbital seta. Occipital setae small. Interfrontalia with 3 pairs of small subequal setae. A minute setula outside the lowermost interfrontal seta present. Eye height about twice as long as genal height. Aristal hairs twice as long as aristal width at base. Genal seta small.

Thorax: Scutum convex dorsally. Thoracic chaetotaxy: 1 long humeral seta; anterior dorsocentral seta half length of posterior dorsocentral, posterior dorsocentral 0.7 times as long as scutellum length; acrostichal setae in 4 rows in front of suture. Lateral scutellar seta half length of apical scutellar, apical scutellar seta 1.3 times as long as scutellum length. Mid tibia: setae generally small in contrast to other species, proximal anterodorsal seta longer than distal anterodorsal, distal posterodorsal seta much smaller and hair-like, ventroapical seta only half length of width of mid tibia and slightly shorter than distal anterodorsal. Wing and veins pale brown, C brown. C extended slightly beyond R4+5. Cs2 very short, 0.4 times as long as Cs3, crossveins r-m and dm-cu separated by twice the length of dm-cu. R2+3 almost straight, apically not bent up to C. R4+5 sinuate. Appendage of M beyond dm-cu inconspicuous. Alula small and narrow, apically pointed.

Male abdomen: Syntergite 1+2 large, but shorter than tergites 3 and 4 together. Sternite 5 ( Fig. 97 ) strikingly triangular, with deflexed posteromedial lobe carrying a row of 6 short and flat setae and 4 long spine-like setae in front of it. Synsternite 6+7 simple. Epandrium with sparse and short setae. Hypandrium with medial apodeme slender and long but much shorter than phallapodeme. Cercus reduced, with sparse and short setae. Gonostylus ( Figs. 93, 94, 95 ) bilobed; outer lobe square, densely setose, dorsally with a flattened process, internally with a rodlike spine; inner lobe anteriorly broadly bifurcate and with 2 groups of short setae. Postgonite ( Fig. 96 ) long and slender, with apical fourth anteriorly curved. Phallophore ( Fig. 96 ) with an elongate distal part to apex of which a long, bipartite, flagellum-like dorsal sclerite of distiphallus is attached; ventral sclerite of distiphallus relatively long and T-shaped.

Female: Body length 1.6 mm, wing length 1.1 mm. Ventroapical seta of mid tibia slightly longer than that of male. Syntergite 1+2 large, dark pigmented and strongly sclerotized. Tergites 3–5 ( Fig. 98 ) reduced, pale pigmented and slightly sclerotized.

Female postabdomen: Tergite 6 ( Fig. 98 ) reduced, pale pigmented and slightly sclerotized. Tergite 7 ( Fig. 98 ) dark pigmented but paler than syntergite 1+2, with semicircular anteromedial area membranous. Tergite 8 ( Fig. 98 ) tripartite. Tergite 10 ( Fig. 98 ) longer than wide, setulose, with 2 small dark additional sclerites between tergite 8 and tergite 10. Sternite 8 ( Fig. 99 ) anteromedially convex, its posterior half with 2 long posterolateral and 9 short setae. Sternite 10 ( Fig. 99 ) wide and short, setulose, but anterior margin pale and bare, posterior margin with 2 long and 6 short setae. Spermathecae ( Fig. 100 ) ball-shaped, basally with tubercles; dark pigmented sclerotized parts of ducts short, half length of spermatheca body length.

Type material. ( LKLSU, in alcohol): Holotype, male: China, Hubei, Mt. Ta-pieh, County Luotian, Qingtaiguan, sweep, 709 m, N 31°10′ 13.51″, E 115°42′ 57.09″, 3.Jul.2014, Lixin Su. Paratypes, 7 males, 7 females: China, Hubei, Mt. Ta-pieh, County Luotian, Qingtaiguan, sweep, 709 m, N 31°10′ 13.51″, E 115°42′ 57.09″, 3.Jul.2014, Lixin Su.

Etymology. The name “ tapiehella ” is derived from Mt. Ta-pieh where is the type locality.

Comments. On some external characters (cf. antennae orange, fore tarsus or only its 4 basal tarsomeres not paler than other tarsomeres, tergites 3–5 reduced, tergite 5 divided into 2 parts) the species resembles some members of M. fanta group (e.g. M. fanta , M. parafanta , M. furculipexa ) but distinctly differs from them in having only fore tibia and fore tarsomeres 1–4 black, tergites 3–5 much paler, male sternite 5 and genitalia, but its male genitalia (cf. distiphallus with a long double whip-like dorsal and a long ventral sclerites, long anterior projecting of phallophore and short anteriorly projecting lobe of gonostylus) clearly indicate its affinity to M. amphicuspa Roháček & Marshall, 1988 and probably forms its sister species. Because of only one orbital seta and convex scutum, the species seems to be similar to M. niveipennis (Malloch, 1913) and M. xanthosceles Roháček & Marshall, 1988 but differs from the latter in having anterodorsal corner of first flagellomere dark brown, only fore tibia and fore tarsomeres 1–4 black, sternite 5 of male triangular, and spermathecae ball-shaped. From above discussion, M. tapiehella sp. n. and M. amphicuspa should therefore form sister species based on shared character (probable synapomorphy): phallophore ventrally rounded and with an elongate distal part.

Distribution. Oriental: China (Hubei).

Figures

FIGURES 92 – 97. Minilimosina (Svarciella) tapiehella Su, sp. n.: 92, male fore leg, anterior; 93, male genitalia, posterior; 94, male genitalia, lateral; 95, gonostylus, anterior; 96, aedeagus and associated structures, lateral; 97, male sternite 5, ventral.

FIGURES 98 – 100. Minilimosina (Svarciella) tapiehella Su, sp. n.: 98, female abdomen, dorsal; 99, female postabdomen, ventral; 100, spermathecae. (abbreviations: S, sternite; T, tergite)