Sphyracephala nigrimana Loew, 1873

Feijen, Hans R., Feijen, Frida A. A. & Feijen, Cobi, 2025, A revision of the four Afrotropical and Palaearctic Sphyracephala Say (Diptera, Diopsidae) with an illustrated overview of the other five Sphyracephala, ZooKeys 1241, pp. 1-81 : 1-81

Sphyracephala nigrimana Loew, 1873

Figs 78–79 , 80–82 , 83–87 , 88–93 , 94–99 , 100 , 105 , 106 , 107 , 108 , 109 , 110 , 112 , Tables 2 , 3

Sphyracephala nigrimana Loew, 1873: 103. Osten Sacken 1882: 235; Bezzi 1922: 69; Lindner 1925: 167; Brunetti 1928: 273; Frey 1928: 70; Hennig 1941 a: 59, 62, fig. 10 b (scutellar spine indicated as from type), 1941 b: 7, figs 5, 7; Steyskal 1972: 13; Yang and Chen 1988: 142; Feijen 1989: 67; Yang and Chen 1998: 474; Hilger 2000: 340; Simova-Tošić and Stojanović 2000: 149; Nartshuk 2003: 179, pl. 44 fig. 12, 2017: 129; Sidorenko 2004: 456, fig. 228; Hua 2006: 158; Mader 2017: 108; Feijen et al. 2018: 206.

Sphyracephala brevicornis (Say): Portschinsky 1871: 287, “ dans les environs de Vladivostok ” [near Vladivostok, Russia]. Loew 1873: 103; Bezzi 1922: 69; Hennig 1941 b: 7; Nartshuk 2017: 129.

Non Sphyracephala nigrimana : Liu 2009: 67, figs 3 e, 36, 1 ♂, Hongmao Village, Yuanmen, Baisha, Hainan, 19. x. 2007, Yang Ding.

Type series.

Russia: multiple specimens, Nebenfluß des Amur [side river of the Amur], A. Fedtschenko [Alexei Pavlovich Fedchenko, 1844–1873]. Hennig (1941 b) studied several specimens designated as S. nigrimana Loew in the Loew Collection ( ZMHB). Although these specimens carried no location information, Hennig stated they could perhaps be considered “ Typen ” (types). According to Sven Marotzke ( ZMHB, pers. comm., 2024) five specimens could be found: two pins with each one specimen glued to a card, and one pin with three specimens glued to a card. All three cards carried the information “ Coll. Loew ”. In addition, on one card with a single specimen was written “ Sphyracephala nigrimana Loew ”, while on the card with three specimens was added “ Post Dubinskiy 23. iii. 1870 ”. Two microscopic slides were also found labelled “ innerer Kopul. - App. ” [inner genital structure] and “ Hypopygium ” [epandrium]. There can be no doubt that these specimens represent the flies studied and illustrated by Hennig (1941 b: figs 2, 5 A, 7) and that the slides were made by him. The information “ Post Dubinskiy, 23. iii. 1870 ” is new. The collecting date looks reliable and fits the time line. The location Post Dubinskiy could not be traced.

Material studied.

Russia: 1 ♀, 1 ♂, зап. Кедровая Падь., Приморье Городков 19.x.1968, Усадода (?) На стене ( RMNH) [Primorye (Primorsky Krai - region), Kedrovaya Pad Nature Reserve ( Korean Pine Valley Reserve or Cedar Reserve ), on the wall, 43°05'N, 131°30'E, 40–700 m , 19.x.1968, Gorodkov]. Kiril Borissovich Gorodkov (1932–2001) was a Russian entomologist.

Diagnosis.

Sphyracephala nigrimana can be recognised by the following set of characters: central head brown, thorax and abdomen blackish; clothed in small setulae; head subtriangular in anterior view; eye stalk very short, very stout (~ 1.1 × the widest sagittal eye diameter); very small eye span in ♀ and ♂, ~ 39 % of body length; assumed sexual monomorphy with regard to eye span; rectangular basiliform prosternum with medial groove; apical seta / scutellar spine ratio: ~ 3.0; scutellar spine / scutellum ratio: ~ 0.7; small, pale scutellar spines ~ 0.21 mm; transparent wing with pattern of dark brown spots including apical spot, central crossband and basal spots; brown fore femur with apical half darker brown, strongly incrassate (l / w ratio: 2.7–2.9), with two rows of spinous setae (more transparent on outer side); tergite 1 with distinct transverse ridges and vague circular groove, tergite 2 anteriorly with small triangle with transverse ridges; intersternite 1-2 a broad band, laterally connected to main sternite 2; ♀ tergite 7 with 2 small, laterally located, sclerites; ♀ sternite 7 forming 2 small, rounded sclerites with posterior extensions; ♀ cerci rather elongate, l / w ratio: ~ 3.3; ♀ sternite 8 forming 2 large rectangular sclerites; well-developed sclerotised ring, triangular to rounded; surstyli articulate, ventrally directed, parallel-sided, l / w ratio: ~ 4.7, on medial side scope-like, no microtrichia, inner and outer side clothed in setulae. Sphyracephala nigrimana comes closest to the two Nearctic Sphyracephala .

Redescription.

The following redescription considers the original description by Loew (1873), descriptions by Hennig (1941 a, b) and illustrations by Nartshuk (2003) and Sidorenko (2004). In his description, Loew especially indicated the differences with the Nearctic S. brevicornis .

Measurements. Body length ♀ 3.97 mm, ♂ 4.03 mm; eye span ♀ 1.52 mm, ♂ 1.59 mm; wing length ♀ 2.99 mm, ♂ 3.11 mm; length of scutellar spine ♀ 0.22 mm, ♂ 0.20 mm (Tables 2 , 3 ). Loew (1873) only indicated that S. nigrimana was of the same size as S. brevicornis , but that the eye span was smaller. Feijen (1989) gave for S. brevicornis a mean length of body of 4.41 mm for ♀ and 4.25 mm for ♂, while the mean eye span came to 1.93 mm in ♀ and 1.88 mm in ♂. This agrees with Loew’s observation about the relatively smaller eye span in S. nigrimana . The drawing by Hennig (1941 b: fig. 2 )) indicates a body length of 3.44 mm and an eye span of 1.37 mm for an unsexed fly. Sidorenko (2004) gives a body length of 3.5–4.2 mm.

Head. Subtriangular in anterior view (Figs 80 , 81 ); central head dark brown (Figs 78 – 81 ), stalks blackish, below the inner vertical setae and laterally of the antennae small yellowish brown spots; face thinly pruinose (Figs 80 , 81 ) with laterally some whitish setulae; frons (Figs 80 , 81 ) and ocellar tubercle thinly pollinose; arcuate groove distinct, narrow and blackish; facial sulcus shallow and indistinct, no facial teeth, lateroventral corners of face rectangular; clypeus more yellowish brown and more glossy; occiput glossy ventrally of ocellar tubercle, some white setulae dorsally and ventrally (Figs 79 , 80 ); eye stalk very stout, ~ 1.05–1.10 × the widest sagittal eye diameter; eye span very small (Table 2 ) in both female (38.3 % of body length) and male (39.5 % of body length), Hennig’s (1941 b) drawing shows a ratio of 39.8 % for an unknown sex; the two data points for eye span / body length (Figs 100 , 105 , 106 ) are just below the allometric lines for S. brevicornis and S. subbifasciata , so it appears most likely that S. nigrimana is also a monomorphic species; inner and outer vertical setae long, close to 0.5 mm, approx. equal in length to diameter of eye stalk (Figs 80 , 81 ).

Thorax. Collar black, pruinose with laterally tiny glossy spots; scutum and scutellum uniformly black, pruinose (Fig. 78 ), scutellar spines pale but darker basally and apically, covered with tiny setulae (Figs 78 , 79 , 84 ); scutum and scutellum clothed with small blackish setulae; pleura dark black, largely pruinose, glossy sections (Fig. 79 ) include anepisternum and anepimeron (except for posterior edge of anepisternum and dorsal edge of both sclerites), katepisternum (except dorsoposteriorly) and meron (except dorsal and posterior edges); posterior notopleural seta and infra-alar seta long (Fig. 79 ), infra-alar seta slightly larger than posterior notopleural seta, supra-alar carina just visible; basiliform prosternum large, rectangular, with medial groove, prosternum laterally close to propleuron but clearly distinct; scutal length / scutal width ratio: 1.0; scutellum trapezoid; scutellar spines very small, straight, almost aligned with dorsal plane of scutellum, diverging at angle of ~ 75 °; scutellar spine / scutellum (Table 3 ) ratio: 0.75 in ♀ and 0.65 in ♂; scutellar spine / length of body ratio: 0.055 in ♀ and 0.051 in ♂; apical seta / scutellar spine ratio: 3.22 in ♀ and 2.82 in ♂; scutellar length / scutellar width (at base) ratio: 0.63 in ♀ and 0.72 in ♂.

Wing. Almost transparent with distinct pattern of dark brown spots (Figs 78 , 79 , 82 ); apex with small spot in cells r 2 + 3 and r 4 + 5; central irregular crossband running from anterior margin to posterior margin near M 4; crossband darker anteriorly in cells r 1 and r 2 + 3, broadens strongly proximally in cell r 4 + 5 to include crossvein r-m, and narrows posteriorly around crossvein dm-m; from crossvein dm-m a small band runs anteriorly to cell sc; a spot centrally in cell bm + dm along vein M 4; a vague spot in cell m 4 distally of vein CuA + CuP; alula vaguely brown infuscated; vein CuA + CuP from vein CuP onward extending under angle of 30 ° to halfway wing margin in slightly curved line; vein M 4 continuing distal of crossvein dm-m to less than halfway wing margin; cell cua subrectangular (Fig. 82 ); crossvein h indistinct; glabrous area only includes small basal spot in cell br.

Legs. Fore coxa and trochanter brown, thinly pruinose on inner side, with some whitish setulae; fore femur (Figs 83 , 85 ) brown, irregularly dark brown on distal half of inner side, thinly pruinose dorsally and on inner side, clothed in dark setulae; fore tibia and tarsus blackish brown, hence the specific epithet nigrimana (Figs 79 , 85 ), thinly pruinose and with rows of blackish setulae; mid and hind legs brown, femora with dark brown spots on distal third of inner and outer side, tibiae darker brown; fore femur strongly incrassate, l / w ratio: 2.9 in ♀ and 2.7 in ♂ (Table 2 ), two rows of spinous setae on distal half with 6.0 ± 0.0 setae (n = 4), inner row with 4.0 ± 0.0 setae and outer row with 2.0 ± 0.0 setae, two rows of tubercles on distal five-sixth with 52.8 ± 0.6 tubercles (n = 4), inner row with 25.3 ± 0.3 (n = 4) tubercles and outer row with 27.5 ± 0.5 (n = 4) tubercles.

Preabdomen. Tergites (Fig. 86 ) uniformly glossy, blackish brown, with scattered tiny white setulae, setulae laterally longer, darker and more dense; tergite 1 with distinct transverse ridges and vague, shallow circular groove, tergite 2 anteromedially with small triangle with transverse ridges; suture between tergites 1 and 2 distinct; sternites 1–6 glossy, dark brown, all covering the width of the abdomen, well covered with dark setulae; sternites 1 and 2 trapezoid (Figs 87 , 92 ), sternite 1 glossy with a few small setulae, sternite 2 glossy, clothed in small setulae, intersternite 1-2 a solid, slender, darker sclerite, laterally broadening and connected to main sternite 2 (Fig. 92 ); sternites 3, 4 and 5 rectangular sclerites, sternite 3 as long as sternites 4 and 5 together; ♀ sternite 6 (Fig. 88 ) consisting of two rectangular sclerites well separated on the meson; ♂ sternite 6 (Fig. 99 ) represented by two small semi-circular sclerites, medially located.

Female postabdomen. Postabdomen narrow (Fig. 88 ); tergite 6 represented by two elongate, laterally located, sclerites; tergite 7 represented by two small, laterally located, sclerites; tergite 8 two elongate, pruinose sclerites, well separated on the meson (Fig. 89 ); tergum 10 short, triangular, thinly pruinose, one pair of apical setulae; cerci rather elongate, l / w ratio: ~ 3.3, clothed in microtrichia and setulae; sternite 7 consisting of two small, rounded, anteriorly located sclerites with long, narrow, less sclerotised posterior extensions (Fig. 88 ); spiracle 7 in membrane; sternite 8 represented by two large rectangular sclerites, separated on the meson, (Fig. 88 ), clothed in microtrichia and 12 pairs of setulae; subanal plate (Fig. 91 ) pentagonal with posterior corners rounded, apically with three pairs of long setulae, clothed in microtrichia and a few pairs of small setulae; spermathecae (Fig. 93 ) mushroom-shaped with inner structure large, striated, basally broadening cone-shaped, hollow and well sclerotised; sclerotised ring of ventral vagina, well developed, triangular to rounded, anterior side narrow (Fig. 90 ).

Male postabdomen. Syntergosternite 7 + 8 slender, on both sides extending to the venter, (Fig. 98 ), spiracles 7 in membrane; epandrium (Fig. 94 ) rounded, clothed in microtrichia and ~ 25 pairs of setulae; surstyli (Figs 95 , 96 ) articulate, l / w ratio: ~ 4.7, almost parallel-sided, apically rounded, ventrally directed, on inner medial side hollow (scoop-like), no microtrichia, outer and inner sides clothed in setulae (Fig. 96 ); surstyli interconnected via slender processus longi; cerci rounded on lateral sides, length / broadest width ratio: 4.0, clothed in microtrichia and ~ 15 setulae; phallapodeme (lost during preparation) with slender anterior arm, lateral processes slender; ejaculatory apodeme straight, slender, apically ~ 3 × as broad as basally (Fig. 97 ), ejaculatory sac normal-sized.

Biology.

The only observations on the biology of S. nigrimana are by Nartshuk (2017). She mentioned that the species is characterised by gregarious behaviour. More than 150 specimens were collected in one day in the Suputinsky Nature Reserve. They were found to be active from April to the end of October, while adults were assumed to hibernate. Mader (2017) mentions for S. nigrimana the antipodal position during copulation. All (also photographical) records for Sphyracephala and other diopsids show an epipodal position during copulation (e. g., Hochberg-Stasny 1985: figs 24–32). As, in addition, S. nigrimana was listed under European Diptera , this record by Mader can better be disregarded.

Distribution.

The type series originated from a tributary of the Amur River in Russia ( Loew 1873). Bezzi (1922), Hennig (1941 b), and Nartshuk (2017) all agreed that the flies from the vicinity (~ 43°08'N, 131°55'E) of Vladivostok and identified by Portschinsky (1871) as S. brevicornis belonged to S. nigrimana . Hennig (1941 b) also recorded S. nigrimana from “ der Mandschurei ” ( ZMHB). According to Pont and Ackland (2009), this locality is in Heilongjiang, China. Yang and Chen (1988) and Hua (2006) repeated this Chinese record without additional comments. Nartshuk (2017) specified that S. nigrimana is distributed in the Primorsky Territory to the north up to the Bikin-Belimbe line (up to ~ 46°48'N). She also mentions specimens from the Suputinsky Nature Reserve (~ 43°40'N, 132°30'E). Dubatolov (2020) reported on the presence of S. nigrimana in the more northern Bolshekhekhtsirsky Reserve (48°17'N, 132°49'E) near the Amur River. Flies were observed on the sunny wooden wall of the reserve office on 21. x. 2020, 29. ix. 2021 and 14. x. 2021 [sic].

Liu (2009) listed one ♂ S. nigrimana from Hainan, China. From the same island he also recorded the Nearctic S. brevicornis . However, both records are based on misidentifications as can be verified, for instance, from the wing drawings. Biogeographically, these records would also have been highly unlikely.

The northern latitude limits of the Nearctic and Palaearctic Sphyracephala are quite consistent. The Nearctic species reach in Canada 47°36'N for S. subbifasciata and 45°30'N for S. brevicornis ( Feijen 1989) . The most northern record for S. babadjanidesi is found in Hungary with 46°41'N, while for S. nigrimana the northern limit in Russia comes to 48°17'N. Hibernation is found in all four Holarctic species.

Figures

Figure 100. Sphyracephala brevicornis, eye span plotted against body length. Older measurements for S. brevicornis from the 1970 s and 1980 s were also used. These measurements were not elaborated with the required accuracy for allometric studies. However, given the large number of data, the allometric lines obtained could be used, though the R 2 values were rather low. Two data points for S. nigrimana are also presented.

Figure 105. Eye span plotted against body length for males of eight Sphyracephala species. A single data point for S. nigrimana is also shown.

Figure 106. Eye span plotted against body length for females of eight Sphyracephala species. A single data point for S. nigrimana is also shown.

Figure 107. Geometric morphometric PCA analysis of Sphyracephala wing venation patterns. Grey dots represent landmarks that were placed with the aid of straight (dotted) lines through other landmarks (white dots). Asterisks indicate wings from paratypes of S. europaea (junior synonym of S. babadjanidesi).

Figure 108. Hierarchical clustering analysis of principal component scores from the PCA in Fig. 107, using the average clustering method. Branch labels indicate the Approximately Unbiased p-value (AU) and Bootstrap Probability (BP). Asterisks indicate wings from paratypes of S. europaea (junior synonym of S. babadjanidesi).

Figure 109. Hierarchical clustering analysis of principal component scores from the PCA in Fig. 107, using the complete clustering method. Branch labels indicate the Approximately Unbiased p-value (AU) and Bootstrap Probability (BP). Asterisks indicate wings from paratypes of S. europaea (junior synonym of S. babadjanidesi).

Figures 78, 79. Sphyracephala nigrimana, Kedrovaya Pad, Russia 78 ♀, habitus, dorsolateral view 79 ♂, habitus, ventrolateral view. Scale bars: 1 mm.

Figures 80–82. Sphyracephala nigrimana, Kedrovaya Pad, Russia 80 ♀, head, anterior view 81 ♂, head, anterior view 82 ♂, wing. Scale bars: 0.5 mm.

Figures 83–87. Sphyracephala nigrimana, Kedrovaya Pad, Russia 83 ♂, fore femur, inner view 84 ♂, scutellar spine, apical bristle 85 ♂, fore leg, outer view 86 ♀, abdomen, dorsal view 87 ♀, abdomen, ventral view. Scale bars: 0.5 mm (86, 87); 0.2 mm (83–85).

Figures 88–93. Sphyracephala nigrimana, ♀, Kedrovaya Pad, Russia 88 postabdomen, ventral view 89 tergite 8, 10 and cerci, dorsal view 90 sclerotised ring 91 subanal plate, ventral view 92 sternite 1, intersternite 1-2 and sternite 2, ventral view 93 spermathecae. Scale bars: 0.2 mm (92); 0.1 mm (88–91, 93).

Figures 94–99. Sphyracephala nigrimana, ♂, Kedrovaya Pad, Russia 94 epandrium, cerci, surstyli, posterior view 95 surstylus, outer view 96 surstylus, inner view 97 ejaculatory apodeme + sac 98 syntergosternite 7 + 8, anterior view 99 sternite 8. Scale bars: 0.1 mm.

Figures 110–112. 110 Cladogram of Sphyracephala species groups according to Feijen (1989) 111 preferred maximum likelihood phylogeny of the Sphyracephalinae, based on molecular analysis (Jackson 2019, supplemental figure 1, in slightly adapted form). Numbers at nodes represent Ultrafast Bootstrap supports 112 revised cladogram of Sphyracephala species groups.