Sympycnus septentrionalis Pollet

Pollet, Marc, Persson, Magnus, Bøggild, Esben & Crossley, Roy, 2015, A long-lasting taxonomic problem in European Sympycnus resolved, with the description of a new species and data on habitat preferences, Zootaxa 4032 (1), pp. 81-102 : 94-99

Sympycnus septentrionalis Pollet , sp. nov.

( Figs 4–5 , 7 , 9 )

Diagnosis (male). Slender species ( Fig. 4 ). Face narrow, at narrowest width about 0.6 x as wide as postpedicel (length). Antenna ( Fig. 5 ) dark, with postpedicel triangular, as long as deep, and about 0.5 x as long as scape and pedicel combined. Stylus inserted at about middle of upper rim of postpedicel. Coxa I dark brown with metallic reflection, with apical 1/5 pale yellow. Femur I pale yellow, with basal 3/5 dark brown. Femur I with 3–4 and femur II with 4 strong preapical pv bristles, with apical bristle slightly curved (MSSC). Tibia I with indistinct av and pv serration of thin setae along entire length (MSSC). Tibia II without pv bristle. Tarsus I with taI 1 with ventral serration of thin inclined setae, not as long as taI 1 is deep (MSSC). Tarsus III ( Fig. 7 ) with taIII3 laterally flattened on apical 2/3, and taIII4 entirely laterally flattened; taIII3 slightly longer (1.1 x) than taIII2, with 2 posterior bristles at basis, straight with abrupt bend at about apical 1/3, about 1.2 x as long as taIII3; with white pd bristles at basis and on apical 1/2, and bare pd zone in between; taIII4 with white bristles along its entire length.

Description. Male. Head. Face silvery white, greyish below antennae, with shallow central furrow; narrowing below antenna, and parallel-sided towards clypeus, at narrowest width about 0.6 x as wide as postpedicel (length), bare. Frons bronze, strongly dusted brownish. Occiput bronze, slightly dusted, rather convex. Palpus small, 1/4 of eye (mostly less than half of palpus exposed), half-moon shaped (exposed part triangular), basal 1/2 brown, and apical 1/2 pale reddish yellow (mostly only apical 1/2 exposed), with white pollinosity, pale pubescence and without apical bristles. Proboscis brown. Eyes red, pubescent. Po bristles rather long, with about uppermost 8 black, stronger, and lower bristles yellowish white, thin, uniserial; with a few long yellowish white bristles posterior of po bristles on lower occiput. One pair of black postocellar bristles. Antenna ( Fig. 5 ) blackish brown, with scape bare dorsally and pedicel with apical circlet of bristles; postpedicel slightly paler, triangular, as long as deep, and about 0.5 x as long as scape and pedicel combined, with distinct pubescence, especially on apical 1/2; stylus rather basodorsal, inserted at about middle of upper rim; apical stylar segment 9 x as long as basal segment, 2.7 x as long as first three antennal segments combined, with microscopic pubescence. Thorax. Mesonotum including pleura, postpronotum, scutellum and metapleura dark metallic green, with pleura slightly dusted greyish. Scutellum with 2 very strong median bristles, 2 minute lateral ones and a sparse fringe of white setae. Thoracic bristles black; 6 rather equal-sized dc; 8 ac, biserial, nearly reaching 5th dc, strong, bristles about 3 x as long as distance between rows; 2 strong and 1 minute ant pprn, 1 bas pprn, 1 psut ial, 1 sut ial, as long as psut ial and anterior spal, 2 npl, 2 spal, and 1 pal bristles; upper proepisternum with group of about 5 small white setae in front of anterior spiracle, lower proepisternum with 2–5 (mostly 4) white, equal-sized (prothoracic) setae; proepimeron bare, and antepronotum with fringe of erect white and black setae. Abdomen: Six pubescent abdominal segments, T6 triangular in lateral view, slightly longer than T5. Tergites and sternites entirely dark metallic green, with T1-6 with short black inclined setae on disc, and with white inclined setae on sides; T1 with strong bristles on posterior margin (black on disc, and paler on sides); T1-2 with erect white setae laterally. Sternites with white pubescence, S1 with only erect setae on posterior margin, S2-5 with short pubescence, and S4-5 with longer setae on posterior margin. Hypopygium ( Fig. 9 ) with epandrium dark brown, with slight bronze reflection; hypandrium straight, dark brown, with jagged basodorsal margin; phallus narrow, rather straight; apicoventral epandrial lobe rather robust and conical, with two setae at basis and one at extreme apex; surstylus apparently lacking; cercus rather short, rounded triangular, tapering towards apex, white, with greyish base and black apex; postgonites large, whitish, outreaching hypandrium, with bifurcate ventral structure arising at its base and forming two long and thin blackish appendages, running alongside the phallus. Wing. Slightly smoky, without anal lobe, with anal vein only weakly indicated. Veins R4+5 slightly curved, M1+2 with smooth bend, both parallel near wing apex. Proximal section of M1+2 0.8 x as long as apical section. Proximal section of CuA1 1.2 x as long as apical section. CuA x ratio: 3.5. Halter yellow; squamal fringe dark brown. Legs. Overall largely pale yellow, with coxae I–III dark, femur I and III strongly infuscated and tarsi I–III dark; with black bristles. Coxa I dark brown with metallic reflection, with apical 1/5 pale yellow; with very dense pubescence of long white bristles and equal-sized white apical bristles. Coxa II dark brown, yellowish at apex, especially on anterior face; with inclined white setae on anterior face, and one strong white bristle and a few setae on outer margin of anterior face. Coxa III dark brown, with one white, straight external bristle, as long as coxa III, inserted at about basal 2/5, with a few minute setae at base and at coxal apex. Trochanters yellow in leg I, brown in legs II–III. Femur I pale yellow, with basal 3/5 dark brown, slightly curved; with one row of small black inclined av bristles along entire length, longest in basal 1/2, there about 1/ 3 x as long as femur is deep; with 3–4 preapical pv bristles in apical 1/3, with three apical ones stronger, slightly longer than femur is deep, and apical bristle slightly curved. Femur II entirely pale yellow, with 1 strong ad, 1 very small preapical av, and with 4 pv preapical bristles in apical 1/3, with three apical ones stronger, about 0.5 x as long as femur is deep, and apical bristle slightly curved. Femur III pale yellow, with more than apical 1/2 dark brown, especially on dorsal face; with 1 strong ad, 1 small av preapical and 1 small pv preapical bristles; with 1 av, 1 vt and 1 pv row of short inclined black bristles along entire length, producing the av and pv preapical bristles. Tibia I pale yellow, with ad serration of 5–7 robust black bristles on apical 1/2, about 2 x as long as tibia is deep; with 1 thin pd seta at about basal 1/4, as long as tibia is deep, and with indistinct av and pv serration of thin setae along entire length. Tibia II pale yellow, with 3 strong, inclined ad bristles, 3– 4 x as long as tibia is deep, inserted at basal 1/5, and near basal 2/5 and 3/4; with 2 slightly weaker pd bristles, at most 2.5 x as long as tibia is deep, inserted at about basal 1/5 and 3/5; with 4 strong ap bristles; ventral bristles lacking. Tibia III pale yellow, becoming gradually darker towards apex, with apical 1/4–1/5 dark brown; with 2 strong ad bristles, about 2.5 x as long as tibia is deep, and with 6–7 distinctly stronger and several smaller dorsal bristles, strongest ones about 1.5 x as long as tibia is deep, and with 5 ap bristles; with indistinct pd pubescence along entire length, including some longer thin bristles, about as long as tibia is deep. Tarsus I pale yellow, dark brown from apical 1/4 of taI 1 onwards; taI 1 with ventral serration of thin inclined setae, not as long as taI 1 is deep; taI 2-5 very short, combined about 1.3 x as long as taI 1. Tarsus II yellow at basis, dark brown from apical 1/4 of taII1 onwards; taII2-5 combined 1.3 x as long as taII1. Tarsus III ( Fig. 7 ) black, brownish at most at extreme base, with taIII3-4 shiny on inner (posterior) face; taIII2 with two black posterior bristles at apex, 0.3 x as long as taIII2 is long; taIII3 laterally flattened on apical 2/3, and taIII4 entirely laterally flattened; taIII3 slightly longer (1.1 x) than taIII2; taIII3 with 2 brown posterior bristles, inserted at extreme base, straight with abrupt bend at about apical 1/3, about 1.2 x as long as taIII3; with 1–2 dark pd bristles at basis and 2–3 pd bristles on apical 1/2 with bare pd zone in between, bristles at most 0.5 x as long as taIII3 and slightly curved; with 4 white pv bristles on apical 1/2, two basal ones curved and two apical ones straight; taIII4 with bristles along its entire length, including 3 straight, white pd bristles, about 0.5 x as long as taIII4, and with 3 shorter and thinner pv bristles; taIII1-4 with vt inclined black bristles. Length ratios of femur/tibia/tarsomeres 1–5 in leg I: 9.2/9.8/3.9/1.2/1.1/1/1.3, in leg II: 7.3/8.6/3.8/1.7/1.5/1.1/1, and in leg III: 7.4/9.3/2.4/1.7/1.9/1.2/1. Body length: 2.5–3.0 mm (n = 5); wing length: 2.4–2.6 mm, 0.3 x as wide as long (n = 5). Female. Similar to male, except for the following features: more robust stature. Face slightly narrowing in upper 1/2 of epistoma, parallelsided in lower 1/2 and clypeus; with diverging furrows on epistoma, wide, about 2 x as wide as postpedicel (length). Palpus large, nearly 2/5 of eye, elongate triangular, with basal 3/5 brown and apical 2/5 pale reddish yellow, with brown pubescence and with 2 strong brown preapical bristles. Proboscis brown, robust, about 0.5 x as long as eye. Antenna with postpedicel rounded triangular to almost reniform, with blunt apex, 0.8 x as long as deep, about 0.7 x as long as scape and pedicel combined, with short pubescence. Ac irregularly uniserial to biserial, reaching between 4th and 5th dc. Abdomen with 5 pubescent segments, with T6 usually enclosed by T5; S1-6 with short, white pubescence. Coxa I dark brown with metallic reflection, mostly with apical 1/6, at most with apical 1/4 pale yellow. Coxa III dark brown, yellowish at apex, with 1 mostly black but sometimes also white, straight external bristle. Femur I pale yellow, with basal 2/3 dark brown, with one row of indistinct equal-sized short inclined av bristles along entire length. Femur I mostly with 1–2 (rarely 3), and femur II with 1–2 preapical pv bristles at apical 1/8, apical bristle slightly curved, slightly longer than femur is deep. Femur III pale yellow, with at least apical 1/3 dark brown, largely darkened dorsally and extreme apex pale yellow; without ventral bristles. Tibia I with ad serration of 7–9 robust black bristles on apical 1/2, about as long as tibia is deep; with 1 thin pd seta and 1 minute vt seta at about apical 1/4, sometimes with another similar vt seta at middle. Tibia II with 3 ad bristles, 3 x as long as tibia is deep, and 2 pd bristles, 2 x as long as tibia is deep; with one pv bristle at apical 1/3, slightly longer than tibia is deep. Tibia III mainly pale yellow, with apical 1/10 (at most apical 1/5) brown; with row of stronger and smaller dorsal bristles along entire length, at most 1.5 x as long as tibia is deep; with only some indistinct short small pv setae. Tarsus I with taI 1 yellow at base, gradually darkened towards apex (basal 3/4 of taI 1 yellow in some specimens). Tarsus III with taIII3 0.8 x as long as taIII2. Lengths ratio of femur/tibia/tarsomeres 1–5 in leg I: 8.8/9.1/4.1/1.7/1.4/1/1.2, in leg II: 7.9/9.5/4.4/1.9/1.6/1/1, and in leg III: 8.7/10.4/2.9/2.3/1.9/1.2/1. Body length: 2.9–3.2 mm (n=5); wing length: 2.7–3.2 mm, 0.3 x as wide as long (n = 5).

Type material (location codes between brackets refer to Fig. 24 ). HOLOTYPE, ♂, SWEDEN: Södermanland, Trosa, Hunga Södergård nr 1, behind stable ( Fig. 23 ), N58°55.244' E17°31.274' (SE01, see Fig. 24 ), 17.vii–1.viii.2004, MT, leg. B.-E. Bengtsson ( NRM: W). ALLOTYPE, ♀, same data as holotype ( NRM: W). PARATYPES: GERMANY: 3♂, 1♀, Mecklenburg-Vorpommern, Prerow-Darß ( DE 01), 24.vii.1991, SW, leg. A. Stark ( MAPC: W). DENMARK: 1♂, Sjaelland (DK01), leg. Westermann ( ZMUC); 1♂, East Jutland, Ajstrup Krat (DK02), 29.vi.–21.vii.2010, leg. E. Bøggild ( ZMUC); 3♂, Fyn, Arreskov Sø (DK03), 23.viii.1964, leg. N.P. Kristensen ( ZMUC); 1♂, North East Fyn (DK04), leg. Schlick ( ZMUC); 1♂, Fyn, Keldsnor (DK05), 24.vii.1964, leg. O. Martin ( ZMUC); 1♂, Lolland, Bogø (DK06), 8.viii.1922, leg. P. Nielsen ( ZMUC); 2♂, 2♀, Lolland, Sundby Storskov (DK07), 22.vi.1964, leg. L. Lyneborg & N.M. Andersen ( ZMUC); 3♂, North East Jutland, Høstemark (meadow) (DK08), 13–24.v.2007, MT, leg. E. Bøggild ( ZMUC: W); 3♂, same site, 24.v.–7.vi.2007, MT, leg. E. Bøggild ( ZMUC: W); 1♂, North East Jutland, Rebild, St Stendal, N56°50', E9°50' (DK09), 14– 28.vii.2013, MT, leg. E. Bøggild ( MAPC: W); 1♂, North West Jutland, Sennels (DK10), 13.vii.1974, leg. K. Schnack ( ZMUC); 1♀, South Jutland, Augustenborg (DK11), leg. Wustnei ( ZMUC); 1♂, South Jutland, Draved Mose (DK12), 7.viii.1964, leg. O. Martin ( ZMUC); 1♂, West Jutland, Tipperne (DK13), 20.vi.1973, leg. E. Rald ( ZMUC). FINLAND: 1♂, Ahvenanmaa, Finnström, Godby träsk, 60.229, 19.997 (WGS84) (FI01), 21.vii.1942, leg. R. Frey ( MZH), label: Finnström; R. Frey; 4734; 1♂, same data, label: Finnström; R. Frey; 4731. GREAT BRITAIN: 1♂, England, Suffolk, Walberswick TM49.73 (GB01), saltmarsh, 15.vii.2003, leg. R. Crossley ( RCRC); 1♂, Scotland, Culbin Sands NH91.58 (GB02), 16.vii.1991, leg. R. Crossley ( MAPC); 1♂, same site, saltings, 15.vii.1991, leg. R. Crossley ( RCRC). NORWAY: 2♂, Buskerud, Hurum, Østnestangen (NO01), 26.v.– 8.vii.1995, MT, leg. L. O. Hansen ( TEJC: W); 1♂, Oslo, Christiania (now Oslo) (NO02), 21.vii.1894, leg. T. Becker ( ZMHB (Becker coll.)), label: Norwegen / 7. 35145; 1♂, Vestfold, Re, Våle, Langøya (NO03), in calcareous meadow at seashore, 8.vii.–2.viii.1991, MT, leg. L. O. Hansen ( TEJC: W). SWEDEN: 5♂, 3♀, same site as holotype, 20.vii.–2.viii.2003, MT, leg. B.-E. Bengtsson ( NRM: W); 6♂, 9♀, same data as holotype ( NRM: W); 9♂, 5♀, same data as holotype ( MAPC: W); 2♂, Blekinge, Tjärö, 56.169784, 15.048738 (SE02), 2.vii.1967, leg. H. Andersson ( MZLU); 1♂, Gotland, Visby, 57.635294, 18.285627 (SE03), 1.vii.1920, leg. O. Ringdahl ( MZLU); 1♂, Gotland, Norrlanda, Hammars, 57.518727, 18.75967 (SE04), 18.viii.1978, leg. R. Danielsson ( MZLU); 1♂, Skåne, Helsingborg, Skälderviken, 56.273695, 12.83525 (SE05), 12.viii.1918, leg. O. Ringdahl ( MZLU); 1♂, same site, 6.ix.1919, leg. O. Ringdahl ( MZLU); 4♂, Skåne, Lund, N Krankesjön (sandy lake shore), 55.706538, 13.477478 (SE06), 7.vii.1981, leg. H. Andersson ( MZLU); 2♂, Skåne, Högestads mosse, 55.516241, 13.846035 (SE07), 12.vii.1982, leg. H. Andersson ( MZLU); 1♂, Skåne, Kristianstad, Lyngsjö, Lyngsjön, 55.9303, 14.0658 (SE08) (marsh/reedbelt close to lake), 18.vii.2014, SW, leg. M. Persson ( MPEC); 1♂, same data ( MAPC); 3♂, Skåne, Vellinge, Skanör, Skanörs Borg (salt marsh), 55.423862, 12.849350 (SE09), 6.vii.2013, SW, leg. M. Persson ( MPEC); 2♂, same data ( MAPC); 1♂, Småland, Bergkvara, 56.386163, 16.088533 (SE10), 17.vii.1983, leg. R. Danielsson ( MZLU); 3♂, same site, 28–29.vi.1988. leg. R. Danielsson ( MZLU); 3♂, same site, 17– 8.vi.1989; 3♂, same site, 1.vii.1989, leg. R. Danielsson ( MZLU); 2♂, Småland, Söderåkra, Fulvik, 56.457748, 16.124582 (SE11), 25.vi.1989, leg. R. Danielsson ( MZLU); 1♀, Södermanland, Södertälje, Tullgarns näs, Rävsalaviken, N58°57.313', E17°36.453' (SE12), 3.vii.–19.viii.2004, MT, leg. P. Heinonen ( NRM: W); 1♂, same site, 16.vi.–17.vii.2005, MT, leg. P. Heinonen ( NRM: W); 1♀, Västerbotten, Vindelns, Kulbäcksängarna, Kulbäcken meadow, N64°11.413' E19°36.342' (SE13), 1–18.viii.2003, MT, leg. Svartbergets fältstation/T. Lundmark ( NRM: W).

Identification. Male specimens of this species are most easily separated from those of S. pulicarius by the lack of the pv bristle on tibia II (nearly always present in S. pulicarius at apical 1/3), the taIII3 that is slightly longer than taIII2 (0.7 x as long as taIII 2 in S. pulicarius ), and the specific chaetotaxy of taIII3-4 (see Diagnosis; Figs 6, 7 ). Due to the large variation of the shape in S. pulicarius , the postpedicel is not considered a reliable diagnostic feature. Female specimens cannot be reliably separated but the following characters seem the most useful: shape and relative length of postpedicel (always blunt-ended and never as long as wide in S. septentrionalis ), colour of coxa I (dark with mostly only apical 1/6 pale yellow, at most apical ¼; apical ¼ to ½ pale yellow in S. pulicarius ), and colour of external bristle on coxa III (mostly black but sometimes white; only black bristle thus far observed in S. pulicarius ). Females of both species have a small pv bristle on tibia II, which is slightly longer in S. pulicarius .

Distribution. Sympycnus septentrionalis exhibits a primarily northern European distribution ( Fig. 24 ) and has thus far been recorded from England, Scotland, Germany, Denmark, Norway, Sweden and Finland. It is likely to be discovered also in Poland, the Baltic countries, northwestern and northern European Russia, and perhaps even in the Netherlands.

Etymology. The name “ septentrionalis ” is Latin for “ northern ” and refers to the northern European distribution of this species, at least as far as is currently known, and as compared to the current extent of occurrence of S. pulicarius in the Palaearctic.

Figures

FIGURE 23. Type locality of Sympycnus septentrionalis sp. nov. (Sweden, Södermanland, Trosa, Hunga Södergård nr 1, behind stable, N 58 ° 55.244 ' E 17 ° 31.274 '; photo: SMTP).

FIGURE 24. Sympycnus septentrionalis sp. nov., distribution map (capture locations indicated in green). Location codes refer to the type material listing.

FIGURES 2 – 5. Sympycnus pulicarius. 2, habitus; 3, head; Sympycnus septentrionalis sp. nov. 4, habitus; 5, head (photos: M. Persson).

FIGURES 6 – 7. Hind tarsus. 6, Sympycnus pulicarius; 7, Sympycnus septentrionalis sp. nov. (photos: M. Persson).

FIGURES 8 – 9. Hypopygium. 8, Sympycnus pulicarius; 9, Sympycnus septentrionalis sp. nov.; apv lobe: apicoventral epandrial lobe, cer: cercus, hyp: hypandrium, pha: phallus, pgo: postgonites, pgo bva: basoventral appendages of postgonites. Scale: 0.1 mm.