Pteremis vlasovi (Duda, 1938) Roháček, 2024

Roháček, Jindřich, 2024, The genus Pteremis (Diptera: Sphaeroceridae) in the West Palaearctic area, with description of four new species, Acta Entomologica Musei Nationalis Pragae 64 (1), pp. 153-206 : 201-202

P. vlasovi from Central Asia

1 Apterous, with halteres also absent ( Figs 119, 121 ) or winged but with eyes strongly reduced ( Fig. 155 ) and wings milky whitish ( Fig. 149 ); t 2 terminally with only 1 subapical vpa seta ( Figs 140 , 153 ). ....................... 2

– Fully winged ( Figs 1 , 40 ) or wings shortened ( Figs 2, 3 , 17–21 ), wing membrane pale brown fumose ( Figs 16–21 , 78 ) and eyes never reduced ( Figs 1, 2 , 42 ); t 2 terminally always with vpa ( Figs 23 , 97 , 118 ) more distant from apex of tibia and often also va seta (directed in axis of tibia), which can be shortened ( Figs 23 , 57 , 70 ). ...................................................................... 3

2(1) Wingless and without halteres, eye relatively large ( Figs 119, 121 ); laterobasal sc slightly to distinctly longer than apical sc ( Fig. 124 ); preabdomen convex, strongly sclerotized and blackish ( Fig. 121 ); epandrium long-setose ( Fig. 126 ); anterior lobe of gonostylus with posterior oblique longitudinal spinulose ledge terminated by 4 robust blunt spines ( Figs 127, 129 ); female postabdomen strongly narrowed, with S8 relatively large, long and usually upcurved ( Figs 144, 145 ), setose as in Fig. 142 ; female S10 with long setae and medially simple ( Fig. 141 ). ......................... P. apterina sp. nov.

– Fully winged ( Fig. 156 ) but veins pale and wing membrane milky white ( Fig. 149 ), eye reduced ( Fig. 155 ); laterobasal sc markedly shorter than apical sc ( Fig. 151 ); preabdomen weakly sclerotized, pale brown and in female with sclerites reduced ( Figs 162, 163 ); epandrium very shortly setose ( Fig. 158 ); anterior lobe of gonostylus with posterior oblique longitudinal spinulose ledge terminally without robust spines ( Fig. 160 ); female postabdomen less narrowed, with S8 small, transverse, bare, medially narrowly dark-pigmented and posteriorly bearing small, transverse, frame-shaped structure with 4 setulae ( Fig. 167 ); female S10 very shortly setulose only posterolaterally, medially with narrow, ventrally projecting U-shaped fillet-like structure ( Fig. 167 ).. ............. P. vlasovi ( Duda, 1938)

3(1) t 2 with distinct va seta, as long as ( Fig. 24 ) or slightly shorter than vpa ( Fig. 56 ) or at least half length of vpa ( Fig. 71 ). ................................................................... 4

– t 2 with va seta reduced ( Fig. 116 ) or absent ( Fig. 95 ). ... 6

4(3) t 2 with va seta only half length of vpa seta ( Fig. 71 ); wing relatively elongate, less rounded apically ( Fig. 65 ), with R 4+5 distally almost straight, with apex a little upcurved. Generally darker both on head (frons dark brown to blackish and face dark brown) and thorax (almost entirely dark brown, also with pleural sutures and ventral part of sternopleuron brown).Male S5 rather uniformly a densely setose and with posteromedial microtomentose area reduced, short ( Fig. 74 ); gonostylus large compared to epandrium ( Fig. 68 ), and its anterior lobe with ventral, posteriorly directed projection very robust, heavily sclerotized and strongly bent medially ( Fig. 67 ); postgonite distally only slightly dilated ( Fig. 73 ). Female unknown. .............. P. tenebricus sp. nov.

– t 2 with va seta long ( Figs 24 , 56 ); wing relatively wider, with apex broadly rounded ( Figs 16 , 43 ) and R 4+5 distally more strongly upcurved to C or wing shortened ( Figs 17–21 ), usually with dm-cu absent. Head and thorax relatively pale: frons anteriorly reddish brown to orange yellow, face pale brown or yellow, thorax with sutures between pleural sclerites ochreous and/or ventral part of sternopleuron pale brown. Male S5 setose mainly laterally and at sides of much larger posteromedial microtomentose area ( Figs 26 , 51 ); gonostylus small compared to epandrium ( Figs 29 , 46 ), with ventral, posteriorly directed projection slender ( Figs 30 , 48 ); postgonite distinctly dilated distally ( Fig. 50 ) to knob-like ( Fig. 32 ). ................................ 5

5(3) Wing normal ( Fig. 16 ) or shortened ( Figs 17–21 ). t 2 with va seta as long as vpa seta ( Figs 23, 24 ) and both posterior subapical setae short ( Fig. 24 ). Head with frontal lunule, face and gena yellow to ochreous. Male S5 with setae thicker and posteromedial comb formed by more robust, less dense and less numerous spines ( Fig. 26 ); male cercus not bulging dorsolaterally, also ventrally micropubescent, and with only a small tubercle on apex ( Fig. 28 ); anterior lobe of gonostylus with ventral, posteriorly directed projection shorter and apically simple ( Fig. 30 ); posterior lobe of gonostylus with terminal spine robust ( Figs 28, 30 ). Phallophore more robust, distiphallus not dilated dorsoventrally and postgonite strongly sinuate, with apex knob-like ( Fig. 32 ). Female T8 short, with medial pigmented part small ( Fig. 35 ); S8 also shorter, tapered posteriorly and posteromedially (on margin or in membrane behind it) with a pair of small setulae on elevated sockets ( Fig. 38 ); spermathecae ovoid, with a group of spine-like tubercles on tapered base ( Fig. 33 ); sclerotized terminal parts of ducts long and slender, in paired spermathecae fused far from their bodies ( Fig. 37 ). ................................. P. fenestralis ( Fallén, 1820)

– Wing always fully developed ( Fig. 43 ). t 2 with va seta somewhat shorter than vpa seta ( Figs 56, 57 ) and one of posterior subapical setae distinctly enlarged ( Fig. 24 ). Head with frontal lunule, face and gena reddish brown to brown. Male S5 with setae finer and posteromedial comb formed by thinner, dense and more numerous spines ( Fig. 51 ); male cercus distinctly bulging dorsolaterally, ventrally bare ( Fig. 47 ), and terminally modified, provided with subapical protruding curved ledge (with 2 setulae) and flattened apex (see also Fig. 49 ); anterior lobe of gonostylus with ventral, posteriorly directed projection longer, slender and with finely trifurcate apex ( Fig. 48 ); posterior lobe of gonostylus with terminal spine slender and elongate ( Figs 47, 48 ). Phallophore slender with tapered acute apex; distiphallus distinctly dilated dorsoventrally and postgonite slightly sinuate, with less clubbed apex ( Fig. 50 ). Female T8 distinctly longer, with medial part pale-pigmented but large ( Fig. 53 ); S8 longer, with posterior half membranous and provided with a transverse row of 2 long (lateral) setae and 4 medial setulae on elevated sockets ( Fig. 59 ); spermathecae pyriform, with distinct conical part, separated from distal subcircular part by 3 or 4 (some incomplete) rings ( Fig. 61 ); sclerotized terminal parts of ducts relatively shorter and thicker, in paired spermathecae fused near conical parts of spermathecae ( Fig. 61 ). ...................................... P. pulliceps sp. nov.

6(3) t 2 with va seta reduced but present and apex of t 2 posteriorly with 3 small setae ( Fig. 118 ). Humeral callus and notopleural area of thorax brown. Male S5 with large pale-pigmented and micropubescent semicircular area and posteromedial comb of spines wide and composed of dense fine spines ( Fig. 108 ); male cercus micropubescent except for ventral part being flattened and projecting into distinctive ventromedial flat but acutely pointed apex ( Figs 104 ); anterior lobe of gonostylus with anterodorsal process extremely long, far projecting dorsally ( Figs 104, 106 ) and its (more or less separate) dark posteroventral part with robust ventral, posteriorly directed ventral projection heavily sclerotized with simply pointed apex ( Fig. 106 ); phallophore relatively robust and with blunt (ventral) apex ( Fig. 107 ); postgonite with apex dilated but rather shortly lancet-shaped ( Fig. 107 ). Female S8 transversely semioval, with only 2 pairs of setae and reduced micropubescence and its posterior membranous part with a medial group of 2 long sinuate and 4 short setae between them, all on elevated sockets ( Fig. 112 ); S10 transversely subpentagonal, anteriorly broadly emarginate and finely setose ( Fig. 114 ); spermathecae pyriform, with basal conical part separated from ovoid body by only 1 complete ring-shaped ledge ( Fig. 115 ). .............................................. P. ferreus sp. nov.

– t 2 with va seta absent and apex of t 2 posteriorly with only 2 small setae ( Fig. 95 ). Humeral callus and notopleural area of thorax pale brown to pale ochreous. Male S5 with small (short) pale-pigmented and micropubescent semicircular area and posteromedial comb of spines narrower, composed of shorter, less dense and thicker spines ( Fig. 84 ); male cercus with micropubescence in two separate groups (on convex posteromedial part and on ventral part, Fig. 81 ) and its apex terminated by a small rounded lappet ( Fig. 83 ); anterior lobe of gonostylus with short anterodorsal corner ( Figs 82, 85 ) and its posteriorly directed ventral projection spiky jagged and pale-pigmented ( Fig. 85 ); phallophore with (ventral) apex more acute ( Fig. 87 ); postgonite distally elongately spatulate, with apex rounded ( Fig. 87 ). Female S8 longer than broad, pale-pigmented both anteriorly and posteriorly, with more setae in the middle, and with a posteromedial group of 6 longer setae on elevated sockets ( Fig. 91 ); S10 more elongate, semioval, with projecting anterolateral corners and longer setae at posterior margin ( Figs 88 , 93 ); spermathecae pyriform, but each with basal conical part separated from spherical body by 3, or more, usually incomplete, rings ( Fig. 94 ). ....................... P. canaria ( Papp, 1977)

Figures

Figs 119–124. Pteremis apterina sp. nov. 119 – male, holotype, left laterally; 120 – labels of the holotype; 121 – female, paratype, dorsally; 122 – ditto, left laterally; 123 – head of the male paratype, frontally; 124 – head and thorax of the same specimen, dorsally. Scales = 0.5 mm. Photo by M. Deml (119, 121, 122) and J. Roháček (others).

Figs 152–157. Pteremis vlasovi (Duda, 1938), male paralectotype. 152 – left t2 and mt2 dorsally; 153 – ditto, anteriorly; 154 – apex of left t2 and mt2 anteriorly (enlarged); 155 – head, left laterally; 156 – right wing; 157 – male S5 ventrally. Scales = 0.1 mm (Figs 152–155, 157), 0.5 mm (Fig. 156). Adapted from RoHÁĆFK (1983: Figs 1–4, 9).

Figs 149–151. Pteremis vlasovi (Duda, 1938), female paralectotype. 149 – female, right laterally; 150 – labels of this specimen; 151 – head and thorax of the same specimen, dorsofrontally. Scales = 0.5 mm. Photo by E. Wolff.

Figs 138–145.Pteremis apterina sp. nov., male and female, paratypes. 138 – male left t2 and mt2 posteriorly; 139 – ditto, dorsally; 140 – ditto, anteriorly; 141 – female S10, ventrally; 142 – female S8 (unfolded), ventrally, 143 – spectacles-shaped sclerite, ventrally; 144 – female S8 (with posterior part incurved), ventrally; 145 – ditto, laterally. Fig. 142 based on paratype from Santa Maria I., others on paratypes from São Miguel I. Scales = 0.2 mm (Figs 138–140), 0.05 mm (others).

Figs 1–6. Pteremis fenestralis (Fallén, 1820) and its habitats. 1 – female, f. macropt., laterally (Czech Republic); 2 – male, f. brach., laterally (Czech Republic); 3 – male, f. brach., living specimen on grass stem (Czech Republic); 4 – male (topotypic specimen, Sweden), head dorsofrontally; 5 – peat-bog meadow, habitat in the (neo)type locality (Sweden: Huddinge, Gömmaren lake reserve); 6 – montane meadow with tufts of grasses, habitat near Jizerka in the Jizerské hory Mts (Czech Republic). Scales = 0.5 mm. Photo by M. Deml (1, 2) and J. Roháček (others).

Figs 40–45. Pteremis pulliceps sp. nov. and its habitats. 40 – male, holotype, left laterally; 41 – labels of the holotype; 42 – holotype, head and thorax, left laterofrontally; 43 – right wing, male paratype; 44 – type locality: upper part of valley of Ribeira de Janella nr. Rabaçal, Madeira; 45 – microhabitat of the species, leaf litter in laurel forest nr. Rabaçal. Scales = 0.5 mm. Photo by J. Roháček.

Figs 16–21. Pteremis fenestralis (Fallén, 1820), wings. 16 – f. macropt., male; 17–21 – f. brach.; 17 – female with dm-cu preserved; 18 – female (f. nivalis); 19 – male (f. subapterus); 20 – female (f. nivalis); 21 – male (f. subapterus). Figs 16–20 are based on specimens from Rejvíz, peat-bog meadow (Czech Republic); Fig. 21 on specimen from Muonio (Finland). Scale = 0.5 mm. Photo by J. Roháček.

Figs 75–80. Pteremis canaria (Papp, 1977) and its habitats. 75 – male, holotype, left laterally; 76 – female (Canary Is, Tenerife,Aguamansa nr. Orotava), left laterally; 77 – labels of the holotype (locality label with obverse and reverse); 78 – right wing, female (from Aguamansa); 79 – valley of a dry brook in a pine forest, habitat of P. canaria near Aguamansa; 80 – pine forests (Pinus canariensis) in the vicinity of Aguamansa. Scales = 0.5 mm. Photo by M. Deml (76) and J. Roháček (others).

Figs 22–27. Pteremis fenestralis (Fallén, 1820), topotypic male (Sweden: Huddinge). 22 – left t2 and mt2 dorsally; 23 – ditto, anteriorly; 24 – apex of left t posteriorly; 25 – male 5th abdominal segment and postabdomen, left laterally; 26 – male S5, ventrally; 27 – 5th abdominal segment and postabdomen 2 (genitalia omitted), ventrally. Scales = 0.2 mm (Figs 22–24), 0.1 mm (others). For abbreviations see Material and methods.

Figs 91–97. Pteremis canaria (Papp, 1977), female (Tenerife, Aguamansa nr. Orotava). 91 – S8, ventrally; 92 – spectacles-shaped sclerite, ventrally; 93 – S10, ventrally; 94 – spermathecae; 95 – left t2 and mt2 posteriorly; 96 – ditto, dorsally; 97 – ditto, anteriorly. Scales = 0.05 mm (Figs 91–94), 0.2 mm (others).

Figs 112–118. Pteremis ferreus sp. nov., male and female, paratypes.112 – S8, ventrally; 113 – spectacles-shaped sclerite, ventrally; 114 – S10, ventrally; 115 – spermathecae; 116 – male left t2 and mt2 posteriorly; 117 – ditto, dorsally; 118 – ditto, anteriorly.Scales = 0.05 mm (Figs 112–115), 0.2 mm (others).

Figs 55–61. Pteremis pulliceps sp. nov., male, female, paratype. 55 – male left t2 and mt2 dorsally; 56 – ditto, posteriorly; 57 – ditto, anteriorly; 58 – spectacles-shaped sclerite, ventrally; 59 – S8, ventrally; 60 – S10, ventrally; 61 – spermathecae. Scales = 0.2 mm (Figs 55–57), 0.05 mm (others).

Figs 67–74. Pteremis tenebricus sp. nov., male, holotype. 67 – external genitalia, caudally (aedeagal complex, left gonostylus and micropubescence of right cercus omitted); 68 – ditto, left laterally; 69 – left t2, dorsally; 70 – left t2 and mt2, anteriorly; 71 – apex of left t2 and mt2, posteriorly; 72 – gonostylus, laterally; 73 – aedeagal complex, laterally; 74 – male S5, ventrally. Scales = 0.1 mm (Figs 67, 68, 73, 74), 0.2 mm (Figs 69–71), 0.05 mm (Fig. 72).

Figs 125–131. Pteremis apterina sp. nov., male, paratype (São Miguel I., Sete Citades). 125 – external genitalia, caudally (aedeagal complex and left gonostylus omitted); 126 – ditto, left laterally; 127 – anterior lobe of gonostylus, left laterally; 128 – posterior lobe of gonostylus, left laterally; 129 – posteroventral part of anterior lobe of gonostylus, left laterocaudally; 130 – aedeagal complex, laterally; 131 – male S5, ventrally. Scales = 0.05 mm (Figs 125–130), 0.1 mm (Fig. 131).

Figs 162–164. Pteremis vlasovi (Duda, 1938), female paralectotype.162 – whole abdomen, dorsally; 163 – ditto, ventrally; 164 – spermathecae.Adapted from RoHÁĆFK (1983: Figs 10–12). Scales = 0.3 mm (Figs 162, 163), 0.05 mm (Fig. 164). For abbreviations see Material and methods.

Figs 158–161. Pteremis vlasovi (Duda, 1938), male paralectotype. 158 – external genitalia, left laterally; 159 – ditto, caudally (aedeagal complex omitted); 160 – gonostylus, left laterally; 161 – aedeagal complex, laterally. Adapted from RoHÁĆFK (1983: Figs 5–8). Scales = 0.05 mm (Figs 158–160), 0.1 mm (Fig. 161). For abbreviations see Material and methods.

Figs 165–167.Pteremis vlasovi (Duda, 1938), female paralectotype. 165 – postabdomen, dorsally; 166 – ditto, left laterally; 167 – ditto, ventrally.Adapted from RoHÁĆFK (1983: Figs 13–15). Scale = 0.1 mm. For abbreviations see Material and methods.

Figs 62–66. Pteremis tenebricus sp. nov., male holotype. 62 – whole specimen after dissection (most of abdomen and left wing removed), left laterally; 63 – labels of the holotype; 64 – head and thorax, left laterofrontally; 65 – left wing; 66 – left mid tibia, anteriorly. Scales = 0.5 mm. Photo by J. Roháček.

Figs 46–51. Pteremis pulliceps sp. nov., male, paratype. 46 – external genitalia, left laterally; 47 – ditto, caudally (aedeagal complex and left gonostylus omitted); 48 – gonostylus, laterally; 49 – apex of cercus, left laterally; 50 – aedeagal complex, laterally; 51 – male S5, ventrally. Scales = 0.05 mm (Figs 46, 47, 50), 0.03 mm (Figs 48, 49), 0.1 mm (Fig. 51).

Figs 28–32. Pteremis fenestralis (Fallén, 1820), topotypic male (Sweden: Huddinge). 28 – external genitalia, caudally (aedeagal complex omitted); 29 – ditto, left laterally; 30 – gonostylus, laterally; 31 – epandrium and hypandrium (setosity omitted), anteriorly; 32 – aedeagal complex, laterally. Scales = 0.05 mm (Fig. 30), 0.1 mm (others). For abbreviations see Material and methods.

Figs 33–39.Pteremis fenestralis (Fallén, 1820), female.33 – spermatheca; 34 – postabdomen,laterally; 35 – ditto, dorsally; 36 – ditto, ventrally; 37 – paired spermathecae; 38 – S8, ventrally; 39 – S10, ventrally. Scales = 0.05 mm (Figs 33, 37–39), 0.1 mm (others). For abbreviations see Material and methods.

Figs 52–54. Pteremis pulliceps sp. nov., female, paratype. 52 – postabdomen, laterally; 53 – ditto, dorsally; 54 – ditto, ventrally. Scale = 0.1 mm.

Figs 104–108. Pteremis ferreus sp. nov., male, paratype. 104 – external genitalia, caudally (aedeagal complex and left gonostylus omitted); 105 – ditto, left laterally; 106 – gonostylus, left laterally; 107 – aedeagal complex (with aedeagus separated), laterally; 108 – male S5, ventrally. Scales = 0.1 mm (Figs 104, 105, 107, 108), 0.05 mm (Fig. 106).

Figs 81–87. Pteremis canaria (Papp, 1977), male, paratype. 81 – external genitalia, caudally (aedeagal complex and left gonostylus omitted); 82 – ditto, left laterally; 83 – apical parts of cerci, ventrocaudally; 84 – male S5, ventrally; 85 – gonostylus, left sublaterally; 86 – posterior lobe of gonostylus, left laterally; 87 – aedeagal complex, laterally. Scales = 0.1 mm (Figs 81, 82, 84, 87), 0.05 mm (others).

Figs 88–90. Pteremis canaria (Papp, 1977), female (Tenerife, Aguamansa nr. Orotava). 88 – postabdomen, laterally; 89 – ditto, dorsally; 90 – ditto, ventrally. Scale = 0.1 mm.