Diopsis Linnaeus, 1775: 5.

Diopsis brevicornis Say, 1817: 23, by monotypy.

Figures 1, 2. 

Prosternum, ventral view 1 basiliform prosternum, ♂, Sphyracephala munroi, Arusha, Tanzania 2 precoxal bridge, ♂, Sphyracephala beccarii, Mboma, DR Congo. Scale bars: 0.1 mm.

Figures 3, 4. 

♀, sternite 8, ventral view 3 Sphyracephala munroi, Arusha, Tanzania 4 Sphyracephala beccarii, Maputo, Mozambique. Scale bars: 0.1 mm.

https://www.flickr.com/search/?text=sphyracephala%20europaea.

Sphyracephala babadjanidesi. Azerbaijan: 6 syntypes (♂ and ♀), Elizavetpol [later Ganja, then Kirovabad, now Ganja], vi.1916, vi.1917; type series lost according to Nartshuk (2017), who designated a neotype, ♂, Azerbaijan, окр. Ганжи, р. Качкарка [okr. Ganzhi, r. Kachkarka, 40°40'12"N, 46°16'33"E], 2.vii.1933, Lukyanovich (ZIN). Type location and the nearby neotype location are well into the Asian part of Azerbaijan.

Figure 5. 

Sphyracephala babadjanidesi, eye span plotted against body length. Most data points were supplied by A. Stojanović (NHMBEO). These Serbian data were also used by Simova-Tošić and Stojanović (2000). Data points for two Azerbaijan flies are marked in blue, while data points of four Hungarian flies are marked in black and white.

Sphyracephala europaea. Hungary: holotype, ♂, Szeged, Maros-torok, magaspart [~ 46°14'24"N, 20°14'14"E ~ 100 m], 26.iv.1997. Paratypes, 10 ♂, 7 ♀, same locality and date; 1 ♀, same locality, 16.x.1996 (all in HNHM).

Azerbaijan: 1 ♀, 1 ♂, Болчалы ЮЗ Гянджи, Азербайджан, Лукъянович 17.vii.1933, Sphyracephala babadjanides [sic], det. Nartshuk (RMNH) [Bolchaly (= Balchili), sw Ganja, Lukyanovich, 40°40'12"N, 46°16'33"E, 17.vii.1933, ~ 500 m]. Azerbaijan is mainly located in West Asia, but a small part (5½ districts) in the North is part of Europe as the Caucasus form the division between Eastern Europe and Western Asia. From 1920 to 1991, Azerbaijan was part of the Soviet Union (USSR). Fyodor K. Lukyanovich (1904–1942) was a Russian entomologist. Hungary: paratypes of S. europaea, 2 ♀, 2 ♂, Szeged, Maros-Torok, magaspart, 26.iv.1997, Paulovics and Földvári (HNHM); Georgia: 1 ?, Kakheti, Signagi, Vakiri, 41°38'43.368"N, 45°55'27.3"E [390 m], 17.vii.2024, S. Kiladze (photographs, see https://www.inaturalist.org/observations/229960704).

Sphyracephala babadjanidesi can be recognised by the following set of characters: head mainly blackish brown, face and anterior edge of frons brown; thorax and abdomen blackish; clothed in sparse, small white setulae; eye stalk very stout (~ 0.94–1.02× the widest sagittal eye diameter); very small eye span (~ 1.7–2.2 mm) in ♀ and ♂ (respectively ~ 52% and ~ 60% of body length); very low rate of dimorphism D = 0.39; rectangular basiliform prosternum; apical seta/scutellar spine ratio: 5.4–5.5; scutellar spine/scutellum ratio: 0.43 in ♀ and 0.41 in ♂; very small, scutellar spines whitish but darker basally ~ 0.13 mm; wing almost transparent with brown central and apical spots; fore femur brown with apical third blackish brown, inner side centrally with dark brown diagonal transverse band, strongly incrassate (l/w ratio: 2.7–2.8), two rows of pale slender spinous setae, inner row with ~ 4.5 setae and outer row with ~ 4.0 hardly spinous setae; tergite 1 with distinct subcircular groove; intersternite 1-2 a solid, straight, rod-like sclerite, laterally linked to sternite 2; ♀ tergite 7 consisting of two anteriorly located, triangular sclerites; ♀ sternite 7 with anteriorly two subtriangular plates, posteriorly connected to two subrectangular plates; ♀ sternite 8 two large elongate sclerites; ♀ cerci rather elongate, l/w ratio: ~ 3.2, sharply tapering apically, remarkably curled upward; small sclerotised ring present; surstyli articulate, medially directed, subrectangular with slightly concave apical side, without microtrichia, clothed in setulae, diagonal ridge on basal half of inner side. Sphyracephala babadjanidesi belongs to the S. brevicornis species group and comes closest to S. munroi.

The following redescription considers the original descriptions by Zaitzev (1919) and Papp et al. (1997), and especially also the description and illustrations by Simova-Tošić and Stojanović (2000). Philipp Adamovich Zaitzev (1877–1957) was the founder of research on the insect fauna of the Caucasus.

Measurements . Zaitzev (1919) studied six specimens and gave as length of body 3.7–4.2 mm, eye span 2.2–2.5 mm and wingspan 7–8 mm. Papp et al. (1997) gave as length of body 3.48 mm (holotype ♂), 3.10–3.50 mm (paratype ♂♂), 3.38–4.05 mm (paratype ♀♀); as wing length 3.13 mm (holotype), 2.75–3.20 mm (paratype ♂♂), 3.05–3.65 mm (paratype ♀♀); and as eye span 2.20 mm holotype), 1.90–2.20 mm (paratype ♂♂) and 1.70–2.15 mm (paratype ♀♀). The best series of measurements were given in Simova-Tošić and Stojanović (2000: table 1). However, measurements were given in μm and not, as stated, in mm, so values given must be divided by 1000 to get mm). Their most important measurements are body length ♀ 3.92 mm ± SE 0.05 (range 3.33–4.38, n = 35), ♂ 3.69 mm ± 0.04 (range 3.15–4.13, n = 38), eye span ♀ 2.05 mm ± 0.03 (range 1.68–2.28, n = 35), ♂ 2.21 mm ± 0.04 (range 1.75–2.83, n = 38). We measured the two flies from Azerbaijan and four paratypes from Hungary. For comparison, relevant measurements are summarised in Table 1. All data points for body length and eye span are plotted in Fig. 5. The actual Azerbaijan measurements for the ♀ fit well with the measurements of Zaitzev, but the ♂ is clearly at the lower end of the size range (Fig. 5). In general, measurements for the three countries are well in agreement with each other (Table 1).

Head . Face and anterior edge of frons brown (Figs 6, 7, showing head of flies from Azerbaijan and Hungary); arcuate groove blackish brown; remainder of frons and stalks blackish brown, occiput brown but blackish medially (Figs 8, 9); head uniformly pruinose (Figs 6–9), clothed in sparse white setulae; frons flat; face flat, no facial teeth, lateroventral corners rounded, facial sulcus absent, but ventral facial edges slightly turned upward medially; eye stalk very stout, ~ 0.94–1.02× the widest sagittal eye diameter; eye span very small in both female (52.3% ± SE 0.2% of body length, n = 38) and male (59.7% ± SE 0.5% of body length, n = 41); a dimorphic species, rate of dimorphism very low D = 0.39 (Fig. 5, 105, 106, Table 2) [Carr et al. 2006a also indicated this species as mildly dimorphic]; inner vertical seta long, ~ 0.50 mm, 1.3× diameter of eye stalk; outer vertical seta long, ~ 0.35 mm, 0.9× diameter of eye stalk (Figs 6, 7). For additional figures of the head refer to Zaitzev (1919: fig. 1a), Papp et al. (1997: figs 1–3) and Simova-Tošić and Stojanović (2000: figs 1, 2b, 2c (antennae), 4a, 4b, 4c).

Figures 6, 7. 

Sphyracephala babadjanidesi, head, anterior view 6 ♀, sw Ganja, Azerbaijan 7 ♀, paratype S. europaea, Szeged, Hungary. Scale bars: 0.2 mm.

Figures 8–11. 

Sphyracephala babadjanidesi 8, 9, 11 ♀, sw Ganja, Azerbaijan 8 habitus, dorsal view 9 habitus, lateral view 10 ♀, paratype S. europaea, abdominal apex with curved cerci, ventral view 11 basiliform prosternum. Scale bars: 1.0 mm (8, 9); 0.2 mm (10); 0.1 mm (11).

Thorax . Collar and scutum uniformly black, pruinose (Figs 6, 7, 31), scutellum slightly more blackish brown, pruinose; scutellar spines whitish but darker basally, densely pruinose (Figs 8, 9); scutum and scutellum with sparse setulae; pleura dark black, largely pollinose, only katepisternum and ventral section of anepimeron glossy (Fig. 9); posterior notopleural seta long, infra-alar seta very long (Fig. 8), infra-alar seta more than twice longer than posterior notopleural seta (Simova-Tošić and Stojanović (2000) give for the notopleural seta a length of ~ 0.29 mm and for the infra-alar seta a length of ~ 0.67 mm); supra-alar carina just visible; basiliform prosternum large, rectangular, with deep medial groove, prosternum laterally close to propleuron but distinct; scutal length/scutal width ratio: ~ 0.9; scutellum trapezoid; scutellar spines very small, straight, slightly turned upward, diverging at angle of ~ 50°; scutellar spine/scutellum ratio: 0.43 in ♀ and 0.41 in ♂ (Table 3); scutellar spine/length of body ratio: 0.055 in ♀ and 0.051 in ♂; apical seta/scutellar spine ratio: 5.4 in ♀ and 5.5 in ♂; scutellar length/scutellar width (at base) ratio: 0.57 in ♀ and in ♂. For additional figures of the thorax can be referred to Simova-Tošić and Stojanović (2000: figs 3e, 3f, scutellum and postscutellum).

Wing . Almost transparent with brown central and apical spots (Figs 12, 13 showing wing of flies from Azerbaijan and Hungary); apex with rounded spot in cells r2+3 and r4+5 just extending in cells r1 and m1; central irregular spot running from posterior end of crossvein dm-m to almost vein R2+3, section in cell r2+3 rounded, section in cell r4+5 running from crossvein r-m to crossvein dm-m, section in cell bm+dm in anterodistal corner and along crossvein dm-m; vein CuA+CuP from vein CuP onward extending under angle of 45° to just past halfway wing margin in straight line; vein M4 continuing distal of crossvein dm-m to almost three-quarters the wing margin; cell cua slightly broadening distally, apically rounded (Figs 12, 13); crossvein h distinct; glabrous area only includes tiny basal spot in cell br.

Figures 12, 13. 

Sphyracephala babadjanidesi, wing 12 ♂, sw Ganja, Azerbaijan 13 ♀, paratype S. europaea, Szeged, Hungary. Scale bars: 0.5 mm.

Legs. Fore coxa and trochanter brown, especially anteriorly pruinose, clothed in some white setulae; fore femur (Figs 14, 15 showing femora of flies from Azerbaijan and Hungary) brown, apical third blackish brown on inner and outer side, inner side centrally with dark brown diagonal transverse band, thinly pruinose, sparsely clothed in small setulae; fore tibia dark brown, thinly pruinose; basitarsus dark brown, other tarsomeres brown (Figs 16, 17), thinly pruinose and with rows of blackish setulae; mid and hind legs brown, femora with darker brown apices, hind tibia with darker brown apex; fore femur strongly incrassate (Table 2), l/w ratio in Azerbaijan ♀ 2.69 and in Azerbaijan ♂ 2.82, l/w ratio in two S. europaea paratype ♀ from Hungary 2.77 ± 0.03 (range 2.73–2.80) and in two S. europaea paratype ♂ 2.82 ± 0.03 (range 2.79–2.85) [Papp et al. (1997) stated that the fore femur in S. europaea is definitely thicker than in S. babadjanidesi and a major differential character. Basing themselves on Zaitzev’s (1919) drawing, they gave a ratio width/length for S. babadjanidesi of 27/75 (i.e., l/w ratio: 2.78). According to Papp et al., the ratio length/width in the holotype of S. europaea came to 2.41, while in the paratype females it was 2.44. However, the data at our disposal clearly show no difference in the ratio l/w between S. europaea and S. babadjanidesi.]; fore femur with two rows of pale spinous setae on distal two-thirds (Figs 14, 15), especially the setae on the outer site are very slender and hardly qualify as “spinous”, in total 8.5 ± SE 0.2 setae (n = 10, range 8–9, ♀ and ♂ combined), inner row with 4.5 ± 0.2 (n = 10, range 4–5) setae and outer row with 4.0 ± 0.0 setae (n = 11, range 4); two rows of tubercles on distal three-quarters with in total 50.2 ± 0.4 tubercles (n = 10, range 48–52, ♀ and ♂ combined), inner row with 24.4 ± 0.3 (n = 10, range 23–26) tubercles and outer row with 25.5 ± 0.4 (n = 11, range 23–27) tubercles. Simova-Tošić and Stojanović (2000: fig. 3a) illustrated setae and tubercles on the fore femur.

Figures 14–17. 

Sphyracephala babadjanidesi 14, 15 fore femur, inner side 16, 17 fore leg 14 ♀, sw Ganja, Azerbaijan 15 ♀, paratype S. europaea, Szeged, Hungary 16 ♀, outer side, sw Ganja, Azerbaijan 17 ♂, inner side, paratype S. europaea, Szeged, Hungary. Scale bars: 0.2 mm.

Preabdomen . Tergites (Fig. 8) blackish brown, thinly pruinose, small white setulae especially laterally; tergite 1 with very distinct subcircular groove and vague transverse ridges (Fig. 8, groove also shown in Zaitzev (1919: fig. 1), Papp et al. (1997: fig. 1), and Simova-Tošić and Stojanović (2000: fig. 4d, e); suture between tergites 1 and 2 very distinct; sternites 1–6 dark brown; sternites 1 and 2 glossy, clothed in small setulae (Fig. 18); other sternites thinly pruinose, sparsely clothed in small white setulae; sternite 1 short, trapezoid; intersternite 1-2 a solid straight rod-like sclerite, laterally linked to sternite 2 (Fig. 18); sternite 2 a slightly trapezoid plate; sternites 3–5 rectangular plates; sternite 6 (Fig. 19) somewhat curved, strongly sclerotised, anteromesally a non-sclerotised section.

Figures 18–23. 

Sphyracephala babadjanidesi, ♀, sw Ganja, Azerbaijan 18 sternite 1, intersternite 1-2 and sternite 2, ventral view 19 postabdomen, ventral view 20 postabdomen, dorsal view 21 subanal plate, ventral view 22 sclerotised ring 23 spermathecae. Scale bars: 0.5 mm (18); 0.2 mm (19, 20); 0.05 mm (21–23).

Female postabdomen . Postabdomen (Fig. 19) with “normal” shape, not long and narrow like S. munroi; tergite 7 represented by two glossy, well sclerotised, anteriorly located, triangular sclerites, just separated mesally (Fig. 20); tergite 8 two subrectangular, thinly pruinose, sclerites, separated on the meson; tergum 10 short, on the meson broader and posteriorly rounded, thinly pruinose, one pair of apical setulae; cerci curled upward, a striking feature clearly visible in both females from Hungary and Azerbaijan (Figs 9, 10; see also Simova-Tošić and Stojanović 2000: fig. 4i), rather elongate, l/w ratio: ~ 3.2, sharply tapering apically, clothed in microtrichia and setulae, apically 3 tiny spine-like setulae (Fig. 20); sternite 7 (Fig. 19; see also Papp et al. 1997: fig. 10) with anteriorly two subtriangular, almost bare, plates well separated on the meson, posteriorly these plates are connected to two posterior subrectangular plates just separated on the meson, these latter plates pruinose and clothed in some setulae; spiracle 7 in membrane; sternite 8 represented by two elongate sclerites, well separated on the meson (Fig. 19), pruinose and posteriorly with some setulae; subanal plate (Fig. 21) triangular to mitre-shaped with apically a tiny extension, pruinose, apex with one pair of longer setulae, ~ 9 pairs of setulae posteriorly; spermathecae (Fig. 23) mushroom-shaped with medium-sized, bell-shaped, hollow, more sclerotised, striated, inner structure, no protuberances, spermathecal ducts very short and broadening distally; sclerotised ring of ventral vagina (Fig. 22) small, anteriorly straight and posteriorly semi-circular, arms very slender.

Male postabdomen . Syntergosternite 7+8 very slender and wide, weakly sclerotised; spiracles 7 in membrane just anteriorly of syntergosternite; epandrium (Fig. 24) rounded, with a large mesal gap, clothed in microtrichia and ~ 10 pairs of setulae; surstyli articulate, l/w ratio: ~ 1.5–1.7, almost touching on the meson, (Figs 24–26), simple, subrectangular with slightly concave apical side, outer side (Fig. 25) without microtrichia, clothed in ~ 50 setulae, inner side (Fig. 26) with only 20 setulae and an almost diagonal ridge on basal half; surstyli interconnected via slender processus longi, processus broadening medially (Fig. 24); cerci slender, rather elongate, l/w ratio: 3.9, clothed in microtrichia and on apical half with ~ 10 setulae; phallapodeme (Fig. 28) with slender anterior arm, corners rounded, anterior arm 1.5× longer than posterior arm, lateral processes broad; ejaculatory apodeme straight, slender but apically widening to twice its width (Fig. 27), ejaculatory sac normal-sized. Papp et al. (1997: figs 4, 5, 8) give lateral views of the male genital complex, also illustrating the phallic complex with short male genital process. Simova-Tošić and Stojanović (2000: fig. 5a, b) likewise illustrate the lateral view of the male genital complex.

Figures 24–28. 

Sphyracephala babadjanidesi, ♂, sw Ganja, Azerbaijan 24 epandrium, cerci, surstyli, posterior view 25 surstylus, outer view 26 surstylus, inner view 27 ejaculatory apodeme + sac 28 phallapodeme. Scale bars: 0.1 mm (24, 27, 28); 0.05 mm (25, 26).

Zaitzev (1919) reported that S. babadjanidesi was attracted by electric light in the evening. Papp et al. (1997) reported on hundreds of S. europaea in October on an overwintering site. Returning in April, the flies were there again, though in smaller numbers. Paulovics (1998) presented data on summer occurrences and distribution along the Hungarian Maros river as well as observations on its ethology. The fly preferred plain and sandy parts of the riverbank and avoided the zone covered by mud. Flies were found 0.5–1.5 m from the river edge. On or near a dead frog, seven or eight Sphyracephala were found. A single fly was also found feeding on a dead ant. In a two-week period in October, the number of assembling flies increased from several to ~ 500. Simova-Tošić and Stojanović (2000) found a cluster of a few thousand flies of S. europaea in early November. Males and females occurred in approximately equal numbers. Kutsarov and Hubenov (2019) reported on clusters of thousands of flies in Bulgaria (see Figs 29, 30). Nartshuk (2017) noted the gregarious behaviour of S. babadjanidesi in Azerbaijan. She also noted that there were only small differences in the descriptions for S. babadjanidesi and S. europaea and that the study of type material would be necessary to determine their synonymy. Papp et al. (1997) and Simova-Tošić and Stojanović (2000) reported on 44 ♀♀ and 55 ♂♂ which would give a sex ratio of 1 ♀:1.25 ♂ (Table 4). However, the latter authors stated that ♂♂ and ♀♀ occurred in equal numbers.

Figures 29–31. 

Sphyracephala babadjanidesi, live 29 cluster of flies in cleft, Nikopol, Danube River, Bulgaria (photograph © Yordan Kutsarov) 30 three flies, same data as for 29 31 fly showing fore femur, Szeged. Maros River, Hungary (photograph © Walter Pflieger).

Laboulbeniales (Ascomycota) have never been found on S. babadjanidesi, S. nigrimana, and the two Nearctic Sphyracephala. The long hibernation period might form the reason for this. Rossi and Feijen (2018) noted that Laboulbeniales are common on African Diopsidae, but considerably less common on Oriental Diopsidae. In Afrotropical Sphyracephala Laboulbeniales are very common, but in Oriental Sphyracephala they are rare. It should be noted that the first fossil record of the order Laboulbeniales was found on a fossil diopsid Prosphyracephala in Baltic Amber (Rossi et al. 2005). Grace and Carr (2020) recorded for S. babadjanidesi (as europaea) 4 subfamilies of mariner transposons against none in S. beccarii.

The original type series for S. babadjanidesi (Zaitzev 1919) and its neotype (Nartshuk 2017) all originate from the Ganja Region in the Asian part of Azerbaijan. The neotype forms part of a large collection (ZIN) of more than 500 specimens originating from almost the same place as the type series (Nartshuk 2017). In 2024, S. babadjanidesi was photographed in Georgia (https://www.inaturalist.org/observations/229960704). The type series for S. europaea came from the Maros River in Hungary. This river is a tributary of the Tisza River which in its turn is the main tributary of the Danube. According to Paulovics (1998), the species exists all along the Hungarian part of the Maros (Fig. 31). The species was later (KMNP 2018) recorded from the Körös-Maros Nemzeti Park in Hungary, near the border with Romania (~ 46°41'23"N, 21°10'28"E, ~ 80 m). Rivers in this park are tributaries of the Tisza. Rahmé published pictures (https://www.flickr.com/photos/eurythyrea/5126015816) taken in Makó, Csongrád, Hungary (46°12'11"N, 20°27'11"E, 83 m). Simova-Tošić and Stojanović (2000) extensively reported on the presence of S. europaea in Serbia along the Danube, ca 2 km from the mouth of the Tisza at Stari Slankamen (45°9'5"N, 20°14'44"E, ~ 100 m) Stojanović (pers. comm.) observed the flies again on 14.x.2006 in the same locality. Early in the morning (8:00 am) ~ 40 specimens could be observed in the same hollow on the loess profile. Later, at around 4:00 p.m., more than 200 specimens were gathered in the same place, spread out over an area of ca 3 m². Kutsarov and Hubenov (2019) recorded S. europaea in Bulgaria, east of the town of Nikopol, next to the rocky monastery St. Stefan (43°42'36"N, 24°54'51"E, 60 m) on the limestone rocks along the Danube River on the border with Romania. On the internet references for S. europaea in Romania can be found (https://www.flickr.com/photos/eurythyrea/5126015816). All locations for S. europaea are along the Danube River and its tributaries. Papp et al. (1997) stated “that Hennig (1941b) hypothesized the occurrence of Sphyracephala in South Europe including Hungary”. However, that view, also repeated in Földvári and Meier (2002), cannot be deduced from Hennig’s paper. The various collecting localities and the two type localities are shown on the map (Fig. 32). In Hungary, this fly has a nature conservation status: collecting it carries a 10,000 HUF fine (Turista Magazin 2023).

Figure 32. 

Distribution map for records of Sphyracephala babadjanidesi (red dots). The yellow dot indicates the type locality of S. babadjanidesi, while the blue dot indicates the one for S. europaea.

Papp et al. (1997) described S. europaea and declared it to be the first known species of the family Diopsidae in Europe. However, fossil species are well known from Europe. Papp et al. (1997) considered S. babadjanidesi the most closely related species to S. europaea. By mistake, they reported Armenia as type locality of S. babadjanidesi. Papp and Földvári (in Papp et al. (1997)), while describing S. europaea, had no access to specimens of S. babadjanidesi. They had to rely on the description and illustrations by Zaitzev (1919), which for its time were certainly of a good standard. However, Zaitzev did not study the genitalia of S. babadjanidesi. Describing a closely related species, without access to flies from the type locality of S. babadjanidesi and without knowledge of genitalia morphology, is not a procedure to be recommended.

Papp et al. (1997) list three “features” that are different between S. babadjanidesi and S. europaea. The first one concerns the colour of the fore tarsi. According to Papp et al. “both description and figure [of Zaitzev] say that fore basitarsus and tarsomeres are yellow in Sphyracephala babadjanidesi, contrasting those of S. europaea.” In the description, Papp et al. (1997) state “Fore basitarsus all black, dorsal surface of other fore tarsomeres dark grey, at most 5^th tarsomere light”. Comparison of photographs (Figs 16, 17) clearly shows that the colour of basitarsus and tarsomeres are similar for flies from Azerbaijan and Hungary. The second difference they listed is “No dark hue in r1 cell of Sphyracephala europaea, contrary to S. babadjanidesi.” This feature is certainly a bit overrepresented in Zaitzev (1919: fig. 1), but is not repeated in the text. Now, comparison of the wings shows no difference in this regard (Figs 12, 13). In wings from both Azerbaijan and Hungary, the very apex of cell r1 can be slightly darker. The third difference given by Papp et al. (1997) concerns the l/w ratio of the fore femur. In the section on the legs of S. babadjanidesi, their statement that fore femora of S. europaea are more incrassate, has already been rejected (see above, and Table 1). The measurements given by Papp et al. (1997) are somewhat haphazard and not well presented. Fortunately, Simova-Tošić and Stojanović (2000) later presented high quality measurements for many characters and based on large series of males and females. The graphs for the ratio’s eye span/body length for flies from Azerbaijan, Hungary, and Serbia (Fig. 5) also clearly show no differences in this regard. Likewise, study of the wing morphometrics (Figs 107–109) supports the conspecificity of S. babadjanidesi and S. europaea.

We present comparative colour photographs for flies from Azerbaijan and Hungary for anterior head (Figs 6, 7), wings (Figs 12, 13) and inner side of fore femur and whole fore legs (Figs 14–17, 31). These already give a strong indication that the same species is involved. Comparison with the large sets of genitalia drawings by Papp et al. (1997) and Simova-Tošić and Stojanović (2000) confirms the view that flies from Azerbaijan, Hungary, and Serbia are conspecific.

Sphyracephala (Diopsis) beccarii. Eritrea: Sciotel, Bogos [1870, 15°35'N, 38°20'E, 780 m], 61 syntypes in MSNG (Sforzi and Sommaggio 2021), more syntypes in various other museums (MLUH, NHMUK). No lectotype has been nominated (Sforzi and Sommaggio 2021), although Guiglia (1957) mentioned “Tipo e numerosi cotipi”.

Sphyracephala africana. Tanzania: holotype, ♀, Bondei, [~ 5°00'S, 39°00'E, 100 m, i.1886/87], ZMHB. The holotype is not listed in Rohlfien and Ewald (1970), but it is present in the ZMHB collection (Sven Marotzke, pers. comm. 2024).

It would go too far to list all the S. beccarii we have examined since 1971. Here we only list the totals examined per country or region: Eritrea, syntypes 3 ♀, 3 ♂, Sciotel, Bogos, 1870, O. Beccari (MLUH, V. Röder collection); Algeria, 1 ?sex, Rhouffi, vii.1949, Vaillant (ZSM); Arabian Peninsula 75 ♀, 80 ♂ (see Feijen et al. 2017); Benin, 1 ♀ (RMNH); Botswana, 1 ♀ (RMNH); Burkina Faso, 1 ♂ (RMNH); Cameroon, 1 ♀ (BMSA); DR Congo, 3 ♀, 5 ♂ (CSCA); Ethiopia, 2 ♀, 1 ♂ (FBUB); Gambia 1 ♀ (RMNH); Ghana, 19 ♀, 14 ♂ (RMNH, CSCA); Kenya, 4 ♀, 4 ♂ (RMNH); Madagascar, 528 ♀, 276 ♂ (CAS); Malawi, 314 ♀, 322 ♂, 1971–1975 (RMNH); Mozambique, 131 ♀, 135 ♂, 1976–1982 (RMNH); Niger, 8 ♀ (RMNH); Senegal, 2 ♀ (RMNH); South Africa 6 ♀, 1 ♂ (RMNH); Tanzania, 26 ♀, 35 ♂, 1982–1988 (RMNH); Togo, 17 ♀, 32 ♂ (FBUB, SMF, RMNH; Zambia, 1 ♀ (RMNH); Zimbabwe 7 ♀, 2 ♂ (AMGS, RMNH). In total 622 ♀ and 635 ♂ were examined for Continental Africa and the Arabian Peninsula, giving a balanced sex-ratio of 100 ♀:102 ♂. However, a different picture emerged for Madagascar: 528 ♀and 276 ♂ were found, based on 84 malaise trapping periods in 2002–2004, which gives a sex-ratio of 100 ♀:52 ♂ (see also Table 4). This striking difference will be discussed in the section on sex-ratio.

Sphyracephala beccarii can be recognised by the following set of characters: head brown, thorax and abdomen blackish brown; sparsely covered with small setulae; frons with dark brown semicircular band; occiput yellowish brown; eye stalk stout (~ 0.75–0.80× the widest sagittal eye diameter), moderately sized for a Sphyracephala; very small eye span (~ 2.1 mm) in both ♀ and ♂ (respectively ~ 49% and ~ 53% of body length); monomorphic with rate of dimorphism D = 0.07; distinct precoxal bridge; apical seta/scutellar spine ratio: ~ 3.9; scutellar spine/scutellum ratio: 0.50; small, pale scutellar spines ~ 0.17 mm; transparent wings; fore femur brown with apical fifth dark brown, inner side with dark brown transverse stripe on central third, strongly incrassate, l/w ratio: 2.5–2.6, with two rows of black spinous setae, inner row with ~ 6.0 setae, outer row with ~ 1.2 setae; tergite 1 with vague transverse ridges, on the meson two parallel, longitudinal grooves; intersternite 1-2 very slender, laterally connected to main sternite 2; ♀ tergite 7 and sternite 7 divided in two small sclerites almost touching laterally; ♀ cerci broad, l/w ratio: ~ 1.9; ♀ sternite 8 represented by two small sclerites, almost touching on the meson; no sclerotised ring; surstyli articulate, almost touching on the meson, tapering apically towards an upturned apex, anterior side with microtrichia on basal third and ~ 25 setulae on apical half. Sphyracephala beccarii belongs to the S. hearseiana species group and can be considered the sister species of S. hearseiana.

The following redescription considers the original descriptions by Rondani (1873) and Karsch (1888), description and figures by Hennig (1941b: figs 1, 5d; 1965: figs 46, 49c, 58a), Séguy (1949: figs 6, 7), Vaillant (1953: figs on p. 12), the table of differences between S. beccarii and S. munroi by Collart (1954), descriptions and figures by Descamps (1957: fig. 7b–f), description and illustrations by van Bruggen (1961: figs 13, 14, 16), Feijen (1983: fig. 5), description and figures of antenna by McAlpine (1997: 172, figs 23, 24, 27; 2011, figs 123, 125), figures by Hilger (2000: figs 7.3–7.7), egg description and figures by Meier and Hilger (2000: figs 9–11).

Measurements . Body length ♀ 4.26 mm ± SE 0.04 (range 3.54–4.64, n = 40), ♂ 3.91 mm ± 0.04 (range 3.32–4.27, n = 40), eye span ♀ 2.09 mm ± 0.02 (range 1.75–2.31, n = 40), ♂ 2.08 mm ± 0.02 (range 1.78–2.27, n = 40); wing length ♀ 3.46 mm ± 0.04 (range 3.17–3.60, n = 10), ♂ 3.09 mm ± 0.08 (range 2.75–3.54, n = 10); length of scutellar spine ♀ 0.176 ± 0.004 (range 0.169–0.193, n = 10), ♂ 0.171 mm ± 0.004 (range 0.145–0.193, n = 10). Baker and Wilkinson (2001) found ♀ mean body length 4.97 mm, ♂ 4.50 mm; ♀ mean eye span 2.10 mm, ♂ 2.05 mm.

Head . Central head (Figs 33, 34, 36) brown, arcuate groove dark brown; frons with dark brown semicircular band running from arcuate groove via base of inner vertical seta to ocellar tubercle; stalks dorsally and posteriorly largely blackish; occiput yellowish brown, slightly darker dorsally; head uniformly pruinose (Figs 34, 36), head with a few small black setulae dorsally, ventrally more and longer whitish setulae; arcuate groove distinct blackish; frons with rectangular elevation below ocellar tubercle, grooves laterally of elevation; face flat, no facial teeth, lateroventral corners rounded, facial sulcus absent, but ventral facial edges slightly turned upward medially; eye stalk stout, ~ 0.75–0.80× the widest sagittal eye diameter; eye span very small in both female (49.2% ± SE 0.1% of body length, n = 40) and male (53.3% ± SE 0.1% of body length, n = 40); a monomorphic species with rate of dimorphism D = 0.07 (Figs 37, 105, 106, Table 2); inner vertical seta long, > 0.4 mm, 1.2× diameter of eye stalk; outer vertical seta long, > 0.3 mm, 0.9× diameter of eye stalk (Figs 34, 36). A drawing of the antenna is provided by Feijen (1983: fig. 5). McAlpine (2011: figs 123, 125) provided a scanning electron microscope picture of the conus of the pedicel and a drawing of funiculus and basal segments of arista. McAlpine (1997: figs 23, 24) discussed the taxonomic importance of the ultrastructure of the face and provided electron micrographs of the lower part of face and parafacials and the microtrichose crazed cuticle of face. In a thesis, Jakobs (1997) studied the fine structure of the optical system. Jakobs measured 30 females and 30 males. She found for ratio eye span/body length in females 44.4% and in males 45.8%, whereas she found a rate of dimorphism D = 0.05, clearly indicating a monomorphic species. Baker and Wilkinson (2001) found for ratio eye span/body length in females 42.3% and in males 45.6%, whereas they found a rate of dimorphism D = 0.20 which still qualifies S. beccarii as a monomorphic species.

Figures 33–36. 

Sphyracephala beccarii 33 live photograph, Mikumi, Tanzania (photograph © Stephen Marshall) 34 ♂, head, anterior view, Wadi Maharish, Saudi Arabia 35 ♀, thorax, lateral view, Mahavelo Forest, Madagascar 36 ♀, thorax, dorsal view, Niamey, Niger. Scale bars: 0.5 mm.

Thorax . Collar, scutum and scutellum blackish brown with few small setulae (Figs 35, 36), scutum and scutellum with fine granulated structure; scutellar spines whitish with brown base; pleura blackish brown, uniformly pruinose; posterior notopleural seta quite long; infra-alar seta long, almost twice length of notopleural seta (Fig. 36); supra-alar carina indistinct; distinct precoxal bridge (Fig. 2); scutal length/scutal width ratio: 0.85; scutellum trapezoid, narrowing distally; scutellar spines small, straight, slightly turned upward, diverging at angle of ~ 60°; scutellar spine/scutellum ratio: 0.50 ± 0.01 (n = 25, see Table 3); scutellar spine/length of body ratio: 0.044 ± 0.001 (n = 20); apical seta/scutellar spine ratio: 3.89 ± 0.07 (n = 25); scutellar length/scutellar width (at base) ratio: 0.69 ± 0.01 (n = 20). McAlpine (1997: fig. 27) illustrated the median ventral region of sternopleura, showing double series of pits.

Wing . Transparent with only the faintest brownish hue (Fig. 38); vein CuA+CuP from vein CuP onward extending under angle of 45° to two-thirds of wing margin in straight line; vein M4 continuing distal of crossvein dm-m to one quarter of distance to wing margin; cell cua very narrow, width near base and apex equal (Fig. 38); crossvein h distinct; glabrous area only includes basal quarter of cell br. Wing pictures were provided by van Bruggen (1961: fig. 12). Hilger (2000: fig. 3), Feijen et al. (2017: fig. 11) and Feijen and Feijen (2018: fig. 189). In the drawing by Hilger, cell cua is clearly misrepresented.

Figure 37. 

Sphyracephala beccarii, eye span plotted against body length.

Figures 38–42. 

Sphyracephala beccarii 38 ♂, wing, Diampwe Malawi 39, 40 ♀, fore femur, Wadi Maharish, Saudi Arabia 39 inner view 40 outer view 41 ♂, Limbe, Malawi, fore leg, inner view 42 ♀, Dedza, Malawi, abdomen, dorsal view. Scale bars: 0.5 mm (38, 41, 42); 0.2 mm (39, 40).

Legs. Fore coxa and trochanter very pale, thinly pruinose, with some setulae; fore femur (Figs 39–41) brown, thinly pruinose, apical fifth dark brown on inner and outer side, inner side with dark brown transverse band, dorsally connected to dark apex, sparsely clothed in small setulae; fore tibia dark brown, thinly pruinose; basitarsus brown, other tarsomeres pale, thinly pruinose and with rows of blackish setulae (Fig. 41); mid and hind legs pale brown, femora with dark brown apical third, hind tibia with dark brown apex; fore femur strongly incrassate (Table 2), l/w ratio: 2.48 ± SE 0.02 in ♀ (n = 10) and 2.53 ± 0.03 in ♂ n = 15); fore femur with two rows of black spinous setae on distal half with in ♀ 7.5 ± SE 0.2 setae (n = 16) and in ♂ 6.8 ± 0.2 (n = 16) setae, inner row with 6.0 ± 0.1 (n = 32) setae and outer row with 1.2 ± 0.1 setae (n = 32), two rows of tubercles on distal three-quarters with in ♀ 49.8 ± 0.8 tubercles (n = 16) and in ♂ 46.9 ± 0.6 (n = 16), inner row with 22.3 ± 0.2 (n = 32) tubercles and outer row with 26.1 ± 0.3 (n = 32) tubercles. Curran’s (1928) key separating S. beccarii from S. munroi by the “Tibiæ and tarsi largely or wholly yellowish” for the former and the tibiae and tarsi brown for the latter should be disregarded. Already in Rondani’s (1873) description it was clearly stated “antici .... tibiis, et metatarso nigricantibus”. Collart (1954) in his table indicated as differential characters for S. beccarii that the fore femur was strongly incrassate, hind tibia only black at apex and for S. munroi that the fore femur was moderately incrassate, hind tibia completely black.

Preabdomen . Tergites (Fig. 42) blackish brown, thinly pruinose, small setulae laterally; tergite 1 with very vague transverse ridges, on the meson two parallel, longitudinal grooves (Fig. 42); suture between tergites 1 and 2 just visible; sternites 1–6 brown, all covering the width of the abdomen, sternite 1 and basal half of sternite 2 glossy, other sternites thinly pruinose, sparsely clothed in small white setulae; sternite 1 short, trapezoid; intersternite 1-2 absent, sternite 2 a uniform, slightly trapezoid plate (Fig. 46); sternites 3–6 rectangular.

Female postabdomen . Postabdomen short, broad (Fig. 43); tergite 7 represented by two small, strongly sclerotised, laterally located, sclerites; tergite 8 (Fig. 45) two square, thinly pruinose, sclerites, laterally located, broadly separated on the meson; tergum 10 short, extending posteriorly on the meson, thinly pruinose, one pair of apical setulae; cerci broad, l/w ratio: ~ 1.9, clothed in microtrichia and setulae; sternite 7 consisting of two small, strongly sclerotised, laterally located, angular sclerites, almost touching tergite 7; spiracle 7 located in membrane in between sternites 6 and 7 (Fig. 43); sternite 8 represented by two small sclerites, almost touching on the meson (Fig. 4), near the genital pore, clothed in microtrichia, 6 pairs of long setulae and some small setulae ; subanal plate (Fig. 44) kidney-shaped with rounded apex and rounded anterolateral corners, apex with one pair of longer setulae, clothed in microtrichia and a few pairs of small setulae; spermathecae (Fig. 47) mushroom-shaped with large, bell-shaped, hollow, more sclerotised, striated, inner structure, no protuberances; sclerotised ring of ventral vagina absent. Hilger (2000: figs 4, 5) provides detailed drawings of ventral and lateral views of the postabdomen.

Figures 43–47. 

Sphyracephala beccarii, ♀, 43, 44, 47 Maputo. Mozambique, 45, 46 Zomba, Malawi 43 postabdomen, ventral view 44 subanal plate, ventral view 45 tergite 8,10 and cerci, dorsal view 46 sternites 1 and 2, ventral view 47 spermathecae. Scale bars: 0.2 mm (43, 46); 0.1 mm (44, 45, 47).

Male postabdomen . Syntergosternite 7+8 very slender, extending the width of the abdomen, slightly angular on the meson (Fig. 53); spiracles 7 in membrane; epandrium (Fig. 48) rounded, clothed in microtrichia and ~ 30 pairs of setulae; surstyli articulate, almost encircled by the epandrium, nearly touching on the meson, tapering apically towards an upturned apex (Figs 48–50), outer side with microtrichia on basal third, apical half with ~ 25 setulae (Fig. 49), inner side with only a few small setulae on apical half (Fig. 50); surstyli interconnected via broad processus longi; cerci tapering basally and apically, broadest at one-third from apex (Fig. 48), length/broadest width ratio: 2.8, clothed in microtrichia and on apical half with more than 30 setulae; phallapodeme (Fig. 52) with slender anterior arm, corners pointed, anterior arm slightly longer than posterior arm, lateral processes “vane” broad; phallus broad, short, male genital process hardly sticking out from apex; ejaculatory apodeme straight, very slender (Fig. 51), ejaculatory sac normal-sized.

Figures 48–53. 

Sphyracephala beccarii, ♂, Diampwe River, Malawi 48 epandrium, cerci, surstyli, posterior view 49 surstylus, outer view 50 surstylus, inner view 51 ejaculatory apodeme and sac 52 phallapodeme 53 syntergosternite 7+8, anterodorsal view. Scale bars: 0.1 mm.

Hennig (1941b: figs 1, 5d) illustrated the inner genitalia and epandrium with surstylus. Vaillant (1953: figs on p. 12) presents drawings of the postabdomen, but the surstylus is shown as fused to the epandrium, syntergosternite is lacking and the terms ventral and dorsal should be reversed.

Van Bruggen (1961) stated that male genitalia in Sphyracephala “are too uniform to facilitate identification of the species”. However, Hennig (1941b) already stated that S. beccarii and S. hearseiana are extraordinarily similar, but can be distinguished by epandrium and surstyli (see also Figs 48, 49 and Figs 132, 133). Hilger (2000: figs 6, 7) gives drawings of the lateral views of male postabdomen and the phallic complex while Feijen and Feijen (2021: fig. 48) give a posterior view of the epandrium.

Egg, larva, and pupa. Descamps (1957) was the first to note the reticulation of the chorion of the egg as “non strié longitudinalement” and “un fin réseau de petits polygones irréguliers.” Feijen (1989) stated that the absence of longitudinal ridges might represent a apomorphic character for Sphyracephala. Meier and Hilger (2000) studying three Sphyracephala including S. beccarii, stated that the eggs are “entirely covered with hexagonal reticulation, chorion never striated”. They considered the egg ornamentation as a diagnostic character for the genus. Micrographs were provided of dorsal egg, micropyle, posterior pole (Meier and Hilger 2000: figs 9, 10, 11). Descamps (1957) stated that eggs are laid on decomposing plant material. Descamps (1957: pl. 7, figs c–f) described larva and puparium and illustrated larval cephaloskeleton, larval posterior spiracles and puparium.

Descamps (1957) reared S. beccarii in Cameroon. Eggs were laid on decomposing plant matter. Descamps described the saprophagous larvae and the time the various stages take. From egg to fly took approximately two weeks. Descamps indicated that S. beccarii often constitute large swarms in the dry season. The flies then disperse at the start of the rainy season. In Algeria, Vaillant (1953) detected among rocks in an oasis swarms of S. beccarii. Feijen (1984) found in the dry season in Malawi among rocks in a river bedding a dense mass of S. beccarii. After being disturbed they flew up. A single sweep of a net yielded more than 6,000 specimens. The size of the whole mass was estimated to be approximately 100,000 specimens, while the cluster took up an area of less than 0.2 m². Feijen et al. (2017) described and illustrated a cluster of more than 80,000 S. beccarii on a tree trunk near a river in Wadi Darbat, Oman. Picker et al. (2019) recorded for South Africa that S. beccarii forms groups in moist, rocky places near water. Their idea that these flies mimic small jumping spiders appears unlikely. Mader (2017) mentions for S. beccarii the antipodal position during copulation. However, all photographs for Sphyracephala and other diopsids show an epipodal position during copulation. Descamps (1957) noted that copulation takes several hours in S. beccarii.

Rossi (1990) described Stigmatomyces beccarii (Laboulbeniales) from S. beccarii, while Stigmatomyces elongatus was described from S. munroi. Both new fungi were described from flies from Malawi. It is interesting to note that these two sympatric Sphyracephala were parasitised by very different Stigmatomyces. Hariri et al. 1998 recorded the presence of the bacteria Type A Wolbachia in S. beccarii. Wolbachia can be associated with female-biased sex ratio distortion. As we report on a female-biased sex ratio in S. beccarii from Madagascar only, it would be interesting to compare the Wolbachia’s in flies from Madagascar and mainland Africa. Carr (2008) found no evidence for the presence of subfamilies of transposable elements in S. beccarii, though three independent lineages were found in S. babadjanidesi (as S. europaea).

Some minor contradictions are found in the records for the rate of dimorphism for S. beccarii. Wilkinson and Taper (1999) considered S. beccarii a monomorphic species. They found an eye span/body length ratio of 0.44 for ♀ and 0.47 for ♂ (we found 0.49 and 0.53 respectively). As rate of dimorphism, they gave D 0.54–0.35 = 0.19 (we found D 0.56 -0.49 = 0.07, see Fig. 37). The same data were presented in Baker and Wilkinson (2001), but due to a difference in rounding off a D of 0.20 is given, while S. beccarii was classified as a dimorphic species. Jakobs (1997) found an eye span/body length ratio of 44.4% for ♀ and 45.8% for ♂, and a rate of dimorphism D = 0.05, indicating a monomorphic species. Carr et al. (2005) stated that S. beccarii has identical mean eye span in males and females, but female body size is greater, leading to sexual dimorphism in relative eye span. However, that is not the way the rate of dimorphism is determined in Diopsidae, cf. Baker and Wilkinson (2001) and Feijen and Feijen (2009, 2021). Referring to the data of Baker and Wilkinson (2001), Cotton et al. (2004a) considered S. beccarii a species with only slight (or weak) sexual dimorphism for eye span. Chapman et al. (2005) considered S. beccarii a sexually monomorphic species. Ribak et al. (2009) found for S. beccarii no significant differences in the mass-adjusted eye-span between the sexes. Voje and Hansen (2013) used for S. beccarii the data of Baker and Wilkinson (2001). Their calculations of allometric slope and intercept were based on the least-squares regression of log eye span as function of log body size. Accordingly, they found that slope and intercept are different between the sexes at the 95% confidence level.

Sphyracephala beccarii is known to occur in almost all contiguous Sub-Saharan African countries and Madagascar. We have seen specimens or records from Benin, Botswana, Burkina Faso, Burundi, Cameroon, Chad, D.R. Congo, Eritrea, Eswatini, Djibouti, Ethiopia, Gambia, Ghana, Kenya, Malawi, Mali, Mozambique, Namibia, Niger, Nigeria, Rwanda, Senegal, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, and Zimbabwe.

Sphyracephala beccarii extends into the Palaearctic Region in Algeria (Bezzi 1922, Hennig 1941b, Séguy 1949, Vaillant 1953). Bezzi referred the Algerian flies to S. hearseiana, but Hennig considered that a likely misidentification for S. beccarii, while Séguy confirmed that the two flies studied by Bezzi belonged to S. beccarii. Vaillant illustrated male genitalia of his Algerian flies and provided reliable information on habitat and swarming. Only his assumptions on the predatory nature of these flies must be rejected. We examined a specimen collected in 1949 in Algeria by Vaillant (ZSM). Papp et al. (1997) considered S. beccarii “an Afrotropical species with one questionable record from Algeria”. However, there is no reason to consider the Algerian records as doubtful. Moreover, Séguy (1950) recorded S. beccarii for Monts Bagzane in northern Niger, not far from Algeria. Sphyracephala beccarii also extends into the Palaearctic Region in the Arabian Peninsula (Feijen et al. 2017). An extensive number of records were provided for Oman, Saudi Arabia, the United Arab Emirates and Yemen. They discussed the delimitation of the Afrotropical and Palaearctic Regions in the Arabian Peninsula.

South Africa: holotype, ♀, Farm Stentor, Barberton, Transvaal [Mpumalanga province, Ehlanzeni District, Nkomazi Local Municipality, 25°33'6"S, 31°22'42"E, 390 m], 7.vi.1925, H. K. Munro (NMSA).

Kenya: 5 ♀, 2 ♂, Mt. Elgon, E. side Kaptega r. [~ 1°11'22"N, 34°45'44"E, ~ 2250 m], 26.i.1975, T. Kronestedt (NHRS); Malawi: 24 ♀, 37 ♂, Nyika, Mondwe valley [10°24'S, 33°50'E, 1760 m], vii.1972, D. Munthali (RMNH); 3 ♀, Zomba, near postoffice [15°22'30"S, 35°19'32"E, 980 m], 18.xi.1973; 3 ♂, 25.xi.1973; 9 ♀ 13 ♂, 27.x.1974, all H.R. Feijen (RMNH); 1 ♂, Zomba, Mlunguzi river, [15°22'30"S, 35°19'18"E, 1140 m], 2.viii.1975; 1 ♀, 7.viii.1975, all H.R. Feijen (RMNH); 1 ♂, Mulanje, Likabula river [15°56'19"S, 35°31'13"E, 1045 m], 5.viii.1974, H.R. Feijen (RMNH); 2 ♀, 3 ♂, Fort Lister, along small river [Phalombe District, 15°49'58"S, 35°40'23"E, 1005 m], 5.viii.1974, H.R. Feijen (RMNH); Tanzania: 10 ♀, 19 ♂, Marangu [3°16'35"S, 37°31'11"E, 1480 m], 30.vi.1978, H.R. Feijen (RMNH); 8 ♀, 13 ♂, Arusha [3°22'15"S, 36°41'48"E, 1400 m], 8.vii.1978; 3 ♀, 2 ♂, 3.viii.1978; 242 ♀, 210 ♂, 9.xi.1978; 1 ♂, 4.vii.1987, all H.R. Feijen (RMNH); 10 ♀, 1 ♂, Arusha Centre [3°22'15"S, 36°41'48"E, 1400 m], 8.viii.1978, H.R. Feijen (RMNH); 1 ♂, Arusha, Mnt Meru hotel [~ 3°21'59"S, 36°42'14"E, 1430 m], 10.ii.1984, G.G.M. Schulten (RMNH); Uganda: 1 ♀, Bundibugyu distr., River Kyemahizi, 0°40'12"N, 30°02'06"E, 920 m, 19.3.2012, M. von Tschirnhaus (FBUB). In total 318 ♀ and 307 ♂ were examined, giving a balanced sex-ratio of 100 ♀:97 ♂ (see also Table 4).

Sphyracephala munroi can be recognised by the following set of characters: head, thorax and abdomen blackish; overall covered with long setulae; brown band below arcuate groove, large brown spots on occiput; eye stalk stout (~ 0.7× the widest sagittal eye diameter), comparatively long and straight for a Sphyracephala; very small eye span (2.5–2.7 mm) in ♀ and ♂ (respectively ~ 61% and ~ 67% of body length); very low rate of dimorphism D = 0.33; rectangular basiliform prosternum; apical seta/scutellar spine ratio: ~ 6.1; scutellar spine/scutellum ratio: 0.44; very small, blackish scutellar spines ~ 0.13 mm; transparent wings with brownish tinge; brown fore femur with apical third dark brown, inner side with dark brown longitudinal stripe on central third, incrassate (l/w ratio: 3.63), with two rows of transparent slender spinous setae, inner row with ~ 2.8 setae, outer row with ~ 4.0 setae; tergite 1 with fine transverse ridges and deep circular groove; intersternite 1-2 mesally a small dark sclerite, laterally narrowly connected to main sternite 2; ♀ tergite 7 with 2 large, rectangular sclerites; ♀ sternite 7 forming two rectangular sclerites with posterior extensions; ♀ cerci elongate, l/w ratio: ~ 4.6; ♀ sternite 8 forming two large rectangular sclerites; no real sclerotised ring, but mesally a tiny structure with thin lateral extensions; surstyli articulate, ventromedially directed, parallel-sided, on medial side hollow, no microtrichia, outer side clothed in setulae, inner side with a comb of fine, small setulae. Sphyracephala munroi belongs to the S. brevicornis species group and comes closest to S. babadjanidesi.

The following redescription considers the original description by Curran (1928), the table of differences between S. beccarii and S. munroi by Collart (1954), and description and illustrations by van Bruggen (1961: figs 13, 14, 16).

Measurements . Body length ♀ 4.2 mm ± SE 0.0 (range 3.7–4.7, n = 40), ♂ 4.1 mm ± 0.0 (range 3.7–4.5, n = 40), eye span ♀ 2.5 mm ± 0.0 (range 2.2–3.0, n = 40), ♂ 2.7 mm ± 0.0 (range 2.2–3.2, n = 40); wing length ♀ 3.5 mm ± 0.0 (range 3.2–3.7, n = 10), ♂ 3.6 mm ± 0.1 (range 3.3–3.8, n = 10); length of scutellar spine ♀ 0.13 ± 0.00 (range 0.10–0.14, n = 10), ♂ 0.13 mm ± 0.00 (range 0.12–0.14, n = 10). Baker and Wilkinson (2001) found ♀ mean body length 5.96 mm, ♂ 5.29 mm, ♀ mean eye span 2.88 mm, ♂ 2.86 mm.

Head . Central head (Figs 54–58) and stalks blackish brown with broad brown band below arcuate groove running from antenna to antenna, basal ventral sections of stalks brown, occiput yellowish brown with dark brown edges; head uniformly pruinose (Figs 57, 58) except for glossy ventral part of clypeus and glossy ventral edge of occiput, head quite setulose; arcuate groove not very distinct, narrow and blackish; frons with slight elevation below ocellar tubercle; face flat, no facial teeth, lateroventral corners rounded, facial sulcus absent, but ventral facial edges slightly turned upward medially; eye stalk stout, ~ 0.7× the widest sagittal eye diameter; eye span very small in both female (61.3% ± SE 0.2% of body length, n = 40) and male (66.7% ± SE 0.5% of body length, n = 40); a dimorphic species with a very low rate of dimorphism D = 0.33 (Figs 60, 105, 106, Table 2); inner vertical seta long, close to 0.5 mm, 1.5× diameter of eye stalk; outer vertical seta long, close to 0.4 mm, 1.1× diameter of eye stalk (Figs 57, 58). Curran (1928) indicated long ocellar setae, but that must be an error. Baker and Wilkinson (2001) found eye span in female to be 48.3% of body length and in male 54.1%, whereas they found a rate of dimorphism of 0.18 which would indicate S. munroi as a monomorphic species.

Figures 54–56. 

Sphyracephala munroi, 54, 55 live photographs 54 Arusha N.P., Tanzania (photograph © Donyo Gabriel) 55 Matema, Tanzania (photograph © Martin Grimm) 56 ♀, Arusha, Tanzania, habitus, dorsal view. Scale bar: 1 mm (56).

Figures 57–59. 

Sphyracephala munroi 57 ♀, head, anterior view, Zomba, Malawi 58 ♂, head, anterior view, Arusha, Tanzania 59 ♀, wing, Arusha. Scale bars: 0.5 mm.

Figure 60. 

Sphyracephala munroi, eye span plotted against body length.

Thorax . Collar blackish, pruinose; scutum, scutellum and scutellar spines uniformly blackish, pruinose and quite setulose (Fig. 56) [Curran (1928) described the scutellar spines as brown, but Collart (1954) and van Bruggen (1961) named the black spines a differential character]; pleura blackish, uniformly pruinose; posterior notopleural seta medium-sized; infra-alar seta long, 3× the length of notopleural seta (Fig. 56); supra-alar carina distinct; basiliform prosternum (Fig. 1) large, rectangular, laterally close to propleuron but clearly distinct [Feijen (1989) noted a precoxal bridge for S. munroi, but that is an error.]; scutal length/scutal width ratio: 0.87; scutellum trapezoid, strongly narrowing distally; scutellar spines very small, straight, slightly turned upward, diverging at angle of ~ 75°; scutellar spine/scutellum ratio: 0.44 ± 0.01 (n = 20, see Table 3); scutellar spine/length of body ratio: 0.033 ± 0.001 (n = 20); apical seta/scutellar spine ratio: 6.10 ± 0.12 (n = 19); scutellar length/scutellar width (at base) ratio: 0.60 ± 0.01 (n = 20).

Wing . Transparent with a faint brownish tinge, especially apically (Figs 56, 59); vein CuA+CuP from vein CuP onward extending under angle of 45° to halfway wing margin in straight line; vein M4 continuing distal of crossvein dm-m to one third of distance to wing margin; cell cua narrow, basally acute, apically rounded (Fig. 59); crossvein h distinct; glabrous area only includes anterior half of cell bc.

Legs. Fore coxa and trochanter pale brown (Fig. 63), coxa densely pruinose on anteriorly directed side, setulose; fore femur (Figs 61–63) pale brown, apical third dark brown on inner and outer side, inner side with characteristic dark brown longitudinal stripe on central third (Fig. 61), outer side thinly pruinose, inner side with subapically a densely pruinose depression, thinly pruinose dorsally and on inner side, clothed in pale setulae; fore tibia and tarsus dark brown, thinly pruinose and with rows of blackish setulae; mid and hind legs pale brown, femora with dark brown apical third, tibiae and tarsi brown; fore femur incrassate (Table 2), l/w ratio: 3.63 ± SE 0.06 in ♀ (n = 10) and 3.63 ± 0.03 in ♂ n = 10); fore femur with two rows of rather transparent, slender spinous setae (almost setula-like and difficult to count, especially on inner side) on distal half with in ♀ 6.0 ± SE 0.4 setae (n = 12) and in ♂ with 7.2 ± 0.3 (n = 12), inner row with 2.8 ± 0.1 (n = 24) setae and outer row with 4.0 ± 0.1 setae (n = 24), two rows of tubercles on distal three-quarters (Fig. 63) with in ♀ 46.5 ± 0.8 tubercles (n = 11) and in ♂ with 44.5 ± 0.6 (n = 11), inner row with 24.2 ± 0.3 (n = 23) tubercles and outer row with 21.3 ± 0.3 (n = 23) tubercles.

Figures 61–65. 

Sphyracephala munroi, ♀, 61, 62 Marangu, Tanzania 63–65 Arusha, Tanzania 61 fore femur, inner view 62 fore femur, outer view 63 fore legs, lateral view 64 abdomen, dorsal view 65 abdomen, ventral view. Scale bars: 0.5 mm (64, 65); 0.2 mm (61–63).

Curran’s (1928) key separating S. beccarii from S. munroi by the “Tibiæ and tarsi largely or wholly yellowish” for the former and the tibiae and tarsi brown for the latter should be disregarded. Collart (1954) in his tabulated key indicated useful differential characters: for S. beccarii “Fémurs antérieurs: fortement grossis. Tibias postérieurs: noirs à l’extrémité seulement.” and for S. munroi “Fémurs antérieurs: modérément épaissis. Tibias postérieurs: entièrement noirs.”

Preabdomen . Tergites (Fig. 64) blackish brown, very thinly pruinose, almost glossy, setulose, especially laterally; tergite 1 with fine transverse ridges and on the meson a large, deep, circular groove (Fig. 64); suture between tergites 1 and 2 visible; tergites 2–6 rectangular; sternites 1–6 brown, all covering the width of the abdomen, clothed in small white setulae, sternites 1 and 2 glossy, sternites 3–6 thinly pruinose; sternite 1 short and trapezoid (Figs 65, 70); intersternite 1-2 mesally a slender dark sclerite, laterally narrowly connected to main sternite 2; sternites 2–5 rectangular sclerites (Figs 65, 66); sternite 6 consisting of two long, elongate sclerites, posteriorly with less sclerotised, narrower extensions (Fig. 66).

Figures 66–71. 

Sphyracephala munroi, ♀, 66, 68–70 Arusha, Tanzania, 67, 71 Zomba, Malawi 66 postabdomen, ventral view 67 tergite 8, 10 and cerci, dorsal view 68 sclerotised ring 69 subanal plate, ventral view 70 sternite 1, intersternite 1-2 and sternite 2, ventral view 71 spermathecae. Scale bars: 0.2 mm (66, 70); 0.1 mm (67, 69, 71); 0.05 mm (68).

Female postabdomen . Postabdomen long, narrow (Fig. 66); tergite 7 represented by two rectangular sclerites, well separated mesally; tergite 8 two rectangular, thinly pruinose, sclerites, separated on the meson; tergum 10 short, posteriorly rounded, thinly pruinose but laterally glabrous, one pair of apical setulae; cerci elongate, l/w ratio: ~ 4.6, clothed in microtrichia and setulae (Fig. 67); sternite 7 consisting of two rectangular, elongate sclerites with long, narrow posterior extension; spiracle 7 in membrane; sternite 8 represented by two large rectangular sclerites, separated on the meson, almost taking up the width of the abdomen, posterolaterally more sclerotised (Fig. 3), clothed in microtrichia and 12 pairs of setulae; subanal plate (Fig. 69) pentagonal with rounded corners, apex with one pair of longer setulae, clothed in microtrichia and a few pairs of small setulae; spermathecae (Fig. 71) mushroom-shaped with medium-sized, bell-shaped, hollow, more sclerotised, striated, inner structure, no protuberances; no real sclerotised ring of ventral vagina, but mesally a tiny curved structure with thin lateral extensions with a very thin, transparent connection between posterior tips (Fig. 68).

Male postabdomen . Syntergosternite 7+8 slender, on both sides extending on the venter, (Fig. 77), spiracles 7 connected to sclerite well before its apices; epandrium (Fig. 72) rounded, clothed in microtrichia and ~ 25 pairs of setulae; surstyli (Figs 73, 74) articulate, l/w ratio: ~ 2.8, ventromedially directed, almost parallel-sided, apically rounded, on medial side hollow (scoop-like), no microtrichia, outer side clothed in setulae on distal three-quarters (Fig. 73), inner side with a few larger setulae on distal half, a comb of fine, small setulae along central ridge of “scoop” (Fig. 74); surstyli interconnected via slender processus longi; cerci (Fig. 72) broadening towards apex, length/broadest width ratio: 1.6, clothed in microtrichia and ~ 20 setulae; phallapodeme (Fig. 76) with club-shaped anterior arm, apically rounded, anterior arm 1.5× longer than posterior arm, lateral processes broad; phallus broad, short, male genital process hardly sticking out from apex; ejaculatory apodeme straight, slender, apically twice as broad as basally (Fig. 75), ejaculatory sac normal-sized.

Figures 72–77. 

Sphyracephala munroi, ♂, Zomba, Malawi 72 epandrium, cerci, surstyli, posterior view 73 surstylus, outer view 74 surstylus, inner view 75 ejaculatory apodeme + sac 76 phallapodeme 77 syntergosternite 7+8, posterior view. Scale bars: 0.1 mm.

Compared with S. beccarii, not much is known about the second Afrotropical species S. munroi. The large numbers of flies collected in Arusha, Tanzania, clearly show that S. munroi can also show gregarious behaviour. However, real clusters (see Feijen et al. 2017) have not yet been reported. Rossi (1990) described Stigmatomyces beccarii (Laboulbeniales) from S. beccarii, while Stigmatomyces elongatus was described from S. munroi. Both new fungi were described from flies from Malawi. It is interesting to note that these Sphyracephala were parasitised by very different Stigmatomyces. Hariri et al. 1998 recorded the presence of bacteria Type A Wolbachia in S. munroi. Wolbachia can be associated with female-biased sex ratio distortion, but such a sex ratio has not been found in S. munroi (Table 4). Feijen (1989) reported on a S. munroi with the venter covered with closely packed mites. In the specimens examined, 3 ♀ and 1 ♂ from 9.xi.1978, Arusha, had the venter covered with mites. Camerik (2006) described the mite Pediculaster kilimanjarensis (Acari: Siteroptidae) from S. munroi collected in Tanzania.

Angola, D.R. Congo, Eswatini, Kenya, Malawi, Mozambique, South Africa, Tanzania, Uganda, Zimbabwe. It appears that S. munroi is confined to Eastern and Southern Africa. However, we have seen some records from West Africa, but those need confirmation. Sphyracephala munroi was, in general, only collected from higher altitudes of 900–2250 m. Only the type locality in South Africa is from a lower altitude (390 m).

Russia: multiple specimens, Nebenfluß des Amur [side river of the Amur], A. Fedtschenko [Alexei Pavlovich Fedchenko, 1844–1873]. Hennig (1941b) 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 (1941b: figs 2, 5A, 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.

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.

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.

The following redescription considers the original description by Loew (1873), descriptions by Hennig (1941a, 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 (1941b: 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 (1941b) 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).

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.

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 r2+3 and r4+5; central irregular crossband running from anterior margin to posterior margin near M4; crossband darker anteriorly in cells r1 and r2+3, broadens strongly proximally in cell r4+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 M4; a vague spot in cell m4 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 M4 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.

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).

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.

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).

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.

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.

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.

The type series originated from a tributary of the Amur River in Russia (Loew 1873). Bezzi (1922), Hennig (1941b), 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 (1941b) 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.