Hylaeus

Yu, Maxim & Dathe, Holger H., 2012, The bees of the genus Hylaeus Fabricius 1793 of the Asian part of Russia, with a key to species (Hymenoptera: Apoidea: Colletidae), Zootaxa 3401, pp. 1-36 : 28-30

Key to the Hylaeus species of the Asian part of Russia

Males

(males of H. montivagus Dathe and H. telmenicus Dathe unknown)

1 Supraclypeal area entirely black, also the rest of the pale mask often reduced..................................... 2

- Supraclypeal area at least basally pale spotted, mask complete................................................. 6

2 Scape black, slender, hardly broadened or bent.............................................................. 3

- Scape with at least a light stripe, more or less broadened...................................................... 4

3 Paraocular spots present ( Fig. 7 g); mesopleura punctured and chagrined, with silky sheen...... H. gracilicornis (Morawitz)

- Paraocular spots missing, face black except clypeus ( Fig. 9 e); mesopleura punctured, interspaces polished, glossy................................................................................................. H. niger Bridwell

4 Clypeus with a yellow spot only ( Fig. 10 i); mesopleura remarkably coarsely punctured, with punctures much larger than on the mesonotum; propodeal enclosure with sharp transverse ribs................................ H. transversalis Cockerell

- Clypeus entirely yellow; mesopleura punctured almost the same as mesonotum; propodeal enclosure with wrinkled mesh ... 5

5 Scape distinctly broadened, inside deeply hollowed out; clypeus polished, only apically with scattered punctures ( Fig. 9 a); larger species, body length 6.5–7.5 mm................................................ H. difformis (Eversmann)

- Scape slightly broadened, inside only shallowly hollowed out; clypeus punctured also on the interior ( Fig. 9 c); smaller species, body length 5.5 mm............................................................... H. nigrocuneatus Cockerell

6(1) Scape distinctly broadened, 1.3 to 1.8 times wider than long, shield-like.......................................... 7

- Scape simple or broadened, but not wider than long.......................................................... 9

7 Scape conspicuously broadened, 1.6 to 1.8 times wider than long; T1 with satin gloss or dull......................... 8

- Scape only up to 1.3 times wider than long; mandibles black ( Fig. 8 e); T1 with finely dispersed punctures, shiny............................................................................................. H. pfankuchi (Alfken)

8 Scape about one and a half times as wide as long; flagellum yellow, brownish above ( Fig. 8 a); mandibles and pronotum often yellow spotted; T1 densely punctured and chagrined, mat....................................... H. dilatatus (Kirby)

- S cape nearly twice as wide as long; middle flagellomeres with dark apices, so flagellum appears ringed ( Fig. 8 c); mandibles and pronotum black; T1 punctured and finely chagrined, with silky gloss................................ H. rinki (Gorski)

9 Axillae white; even mandibles, labrum and pronotum white marked; supraclypeal area impressed, clypeus arched ( Fig. 11 e); sterna with four protuberances........................................................ H. variegatus (Fabricius)

- Axillae black, and features differently combined........................................................... 10

10 Sterna with metasomal protuberances or callosity........................................................... 11

- Sterna flat.......................................................................................... 15

11 S3 with strong triangular hump; S4 arched; scape cylindric thickened, black; mask white with enamel gloss ( Fig. 7 a)......................................................................................... H. nigritus (Fabricius)

- Sterna partly with callosities............................................................................ 12

12 Antennae inserted close together, the distance of antennal sockets from each other less than to the orbits; scape black ( Fig. 5 a); genae long, about the width of the flagellum; pronotum black................................... H. aborigensis Dathe

- Antennae inserted at a normal distance, antennal sockets about as far apart from each other as to the orbits; scape laterally with yellow stripe; genae short, narrower than width of flagellum; pronotum pale marked.............................. 13

13 Head in frontal view of transversely trapezoidal outline; mask polished, shiny ( Fig. 11 c); T1 strongly chagrined and coarsely punctate............................................................................ H. signatus (Panzer)

- Head in frontal view of elongate trapezoidal outline; mask chagrined, mat; T1 very finely chagrined with only scattered, fine punctures........................................................................................... 14

14 Occiput with distinct surrounding carina; supraantennal unpunctated area distinctly larger than antennal socket........................................................................................... H. incongruus Förster 1871

- Occiput rounded, without surrounding carina; supraantennal unpunctated area nearly of the size of antennal socket ( Fig. 11 a)................................................................................... H. confusus Nylander

15(10) Apical margin of S6 with V-shaped incision or emargination.................................................. 16

- Apical margin of S6 weakly convex, curved............................................................... 18

16 Mesopleura very roughly wrinkled punctate, intervals as narrow ridges; mask yellow ( Fig. 10 a); incision of S6 deep V-shaped; pronotum black....................................................................... H. pectoralis Förster

- Mesopleura more or less coarsely punctured, but intervals distinctly recognizable and its surface evenly convex......... 17

17 Basal area of propodeum strongly and extensively wrinkled, distinct even on posterior area; scape enlarged, around 1.6 times longer than apically wide ( Fig. 10 g)...................................................... H. noomen Hirashima

- Basal area of propodeum only wrinkled on basal part, posterior area nearly free of wrinkles; scape inconspicuous, conical..................................................................................................... 18

18 Basal area of propodeum with short longitudinal wrinkles; supraclypeal area in the upper part distinctly narrowed, parallel- sided ( Fig. 10 e)....................................................................... H. globulus (Vachal)

- Basal area of propodeum with a few long transverse wrinkles; supraclypeal area in the upper part triangular ( Fig. 10 c)............................................................................................ H. floralis (Smith)

19 Mesopleura with larger punctures, intervals as large as half to full puncture diameter, shiny; mask white; T1 smooth with fine, apically dense punctures; head as in Fig. 5 g.......................................... H. leptocephalus (Morawitz)

- Mesopleura with normal punctures...................................................................... 20

20 Scape hardly expanded, short or narrow conical or cylindrical................................................. 21

- Scape widened or produced, apically at least twice as wide as at its base......................................... 23

21 Propodeum rounded, with fine sculpture; T1 chagrined, with subtle but distinct punctation; head as in Fig. 7 i.................................................................................................... H. paulus Bridwell

- Propodeum with coarse wrinkles; T1 polished, without punctation.............................................. 22

22 T1 smooth, distinctly punctured; frons chagrined, silkily shiny; paraocular spots constricted on top near orbits, so that the spots appear knob-like ( Fig. 5 e)............................................................ H. angustatus (Schenck)

- T1 polished, without punctures; frons above the antennal sockets with round, smooth, shiny areas; paraocular spots truncated across the top, without knob formation ( Fig. 9 g)........................................... H. concinnus Cockerell

23 Scape enlarged to heart-shape.......................................................................... 24

- Scape conically enlarged............................................................................... 26

24 T1 distinctly chagrined, with flat punctures, silkily shiny; clypeus with long pale bristles, especially at the anterior margin ( Fig. 6 a).............................................................................. H. annulatus (Linnaeus)

- T1 smooth, at most finely striate, shiny; clypeus without long bristles at the anterior margin......................... 25

25 T1 finely striate, with flat scattered punctures; scape apically almost as wide as long; mask lemon yellow; frons without bristle fields ( Fig. 6 c).................................................................. H. cardioscapus Cockerell

- T1 polished, with dense, strong punctation; scape apically only about one and a half times as wide as long; mask ivory-white; frons with two oval bristle fields ( Fig. 5 c)..................................................... H. altaicus Dathe

26 Scape short conical, just as long as the first three antenna segments together; posterior area of propodeum surrounded by sharp edge............................................................................................. 27

- Scape elongated, considerably longer than the first three antenna segments together; posterior area of propodeum without surrounding sharp carinae................................................................................ 28

27 T1 distinctly punctate, particularly apically with dense punctures; pronotum yellow marked; head as in Fig. 6 g................................................................................................ H. sibiricus (Strand)

- T1 only with scarce and very dispersed punctures; pronotum mostly black; head as in Fig. 6 e....... H. communis Nylander

28 Head in frontal view conspicuously prolonged, especially in the lower part narrowed; clypeus longer than the supraclypeal area; sides of the supraclypeal area approximately parallel; mask white, finely longitudinally striated, punctation hardly recognizable ( Fig. 5 i); T1 with white side fringes.......................................... H. dolichocephalus Morawitz

- Face shorter; clypeus about as long as the supraclypeal area; sides of the supraclypeal area downwards divergent; mask ivorywhite, chagrined, with few shallow punctures ( Fig. 7 c); T1 without side fringes................. H. pallescens Cockerell

Figures

FIGURE 5. Subgenus Hylaeus Fabricius. Face: a, b— H. aborigensis Dathe, 3, Ƥ (both Jewish AP); c, d— H. altaicus Dathe, 3, Ƥ (both Tyva Rep.); e, f — H. angustatus (Schenck), 3 (Tyva Rep.), Ƥ (C Europe); g, h— H. leptocephalus (Morawitz), 3 (Jewish AP), Ƥ (Tyva Rep.); i, j— H. dolichocephalus Morawitz, 3, Ƥ (both Tyva Rep.). Scale bar: 1 mm.

FIGURE 6. Subgenus Hylaeus Fabricius. Face: a, b— H. annulatus (Linnaeus), 3, Ƥ (both Magadan Prov.); c, d— H. cardioscapus Сockerell, 3, Ƥ (both Zabaikalskiy Terr.); e, f— H. communis Nylander, 3, Ƥ (both Bashkortostan Rep.); g, h— H. sibiricus (Strand), 3, Ƥ (both Irkutsk Prov.). Scale bar: 1 mm.

FIGURE 7. Subgenus Hylaeus Fabricius. Face: a, b— H. nigritus (Fabricius), 3, Ƥ (both C Europe); c, d— H. pallescens Cockerell, 3 (Altai Rep.), Ƥ (Zabaikalskiy Terr.); e— H. montivagus Dathe, Ƥ (Altai Rep.); f— H. telmenicus Dathe, Ƥ (Altai Rep.); g, h— H. gracilicornis (Morawitz), 3, Ƥ (both Primorskiy Terr.); i, j— H. paulus Bridwell, 3, Ƥ (both Primorskiy Terr.). Scale bar: 1 mm.

FIGURE 8. Subgenus Lambdopsis Popov. Face: a, b— H. dilatatus (Kirby), 3 (Bashkortostan Rep.), Ƥ (Altai Rep.); c, d— H. rinki (Gorski), 3 (Jewish AP), Ƥ (Altai Rep.); g, h— H. pfankuchi (Alfken), 3, Ƥ (both Kunashir). Scale bar: 1 mm.

FIGURE 9. Subgenus Patagiata Blüthgen. Face: a, b— H. difformis (Eversmann), 3, Ƥ (both Bashkortostan Rep.); c, d— H. nigrocuneatus Cockerell, 3 (Zabaikalskiy Terr.), Ƥ (Primorskiy Terr.). Subgenus Nesohylaeus Ikudome. Face: e, f— H. niger Bridwell, 3, Ƥ (both Hokkaido, Japan). Subgenus Paraprosopis Popov. Face: g, h— H. concinnus Cockerell, 3, Ƥ (both Primorskiy Terr.). Scale bar: 1 mm.

FIGURE 10. Subgenus Nesoprosopis Perkins. Face: a, b— H. floralis (Smith), 3, Ƥ (both Honshu, Japan); c, d— H. globulus (Vachal), 3 (Sakhalin), Ƥ (Primorskiy Terr.); e, f— H. noomen Hirashima, 3, Ƥ (both Japan); g, h— H. pectoralis Förster, 3 (C Europe), Ƥ (Primorskiy Terr.); i, j— H. transversalis Cockerell, 3, Ƥ (both Primorskiy Terr.). Scale bar: 1 mm.

FIGURE 11. Subgenus Prosopis Fabricius. Face: a, b— H. confusus Nylander, 3, Ƥ (both Yakutia); c, d— H. signatus (Panzer), 3 (S Europe), Ƥ (Caucasus); e, f— H. variegatus (Fabricius), 3 (Jewish AP), Ƥ (Tyva Rep.). Scale bar: 1 mm.