Hylaeus (Hylaeus) pesenkoi Proshchalykin & Dathe

Proshchalykin, Maxim Yu. & Dathe, Holger H., 2016, Additional records of the genus Hylaeus Fabricius, 1793 (Hymenoptera: Apoidea: Colletidae) from Siberia, with description of a new species, Zootaxa 4105 (4), pp. 301-320 : 310-311

Hylaeus (Hylaeus) pesenkoi Proshchalykin & Dathe , sp. nov.

Figs 9–19

Diagnosis. This species belongs to the nigritus group. The male is characterized by a long face, which is widely impressed in the middle, the supraclypeal area narrow, the scapi flattened and bent, with a white stripe on their outer edge. The female can be identified by its characteristic, nearly rectangular white paraocular spots.

Description. Male. Measurements (n=5): total length 5.6–6.8 (6.01) mm, wing length 4.5–5.0 (4.65) mm.

Head proportions HL:HW 1.07, UHW:LHW 1.80 ( Fig. 9 ), with extended trapezoidal outline, malae protruding below. Scapi elongate, slender conoid and distinctly bent, SL:SW 1.84, their front and back flattened; black with white stripe on the outer edge; flagella long, black, yellow below; flagellomeres also apically yellow, so that the flagella appear partly curled. Mask complete, white, smooth and shiny, only laterally with scattered punctures; side patches expanded beyond scapus bases with apex rounded, ending on protruding humps. A broad central region is impressed, including lower part of supraclypeal area, clypeus base and adjacent paraocular portions. Along the each orbit is a line of erect sensory bristles. Foveae faciales short. Clypeus CL:CW 1.41, lower part strongly bulged, surface smooth and shiny, with scattered punctation, anterior margin dark. Supraclypeal area narrow, only half as wide as the adjacent side of face; upper part pointed, offset from the frons. Frons in the middle shallowly impressed, smooth and glossy, supraantennal area without punctation, otherwise punctation dense, strong; vertex with moderately dense erect pilosity. Genae narrow; occiput rounded; malae conspicuously elongate, edged. Labrum black, sometimes with tiny white dot, mandibles black, bifid. Mesosoma ( Figs 11, 12 ) compact; pilosity short, yellowish. Coloration black, pronotum and calli black, tegulae with white spot. Pronotum bulging expanded, anterior margin and dorsolateral angles blunt. Mesonotum and scutellum hardly shagreen, shiny, punctation strong, dense; metanotum matt, with indistinct punctation; mesopleurae with sculpture similar to mesonotum, anterior margin rounded; mesosternum with round impression, anterolaterally with tubercles. Legs black, anterior surface of foretibiae yellow; bases of other tibiae and basitarsi, and other tarsi brown; wings slightly brown, venation dark brown. Propodeum ( Fig. 10 ) rounded with posterolateral humps, its surface net wrinkled, shiny; basal area delimited by fine carina, terminal area scarcely separated, only below with sharp edges, surface shagreen and finely wrinkled, matt; propodeal furrow shallow, shiny.—Metasoma compact, stocky spindle-shaped, coloration black. T1 ( Fig. 10 ) smooth and shiny, punctation moderate, close to sparse; T2 and following terga more finely and densely punctate; terga without fringes. S3 with widely triangular callosity, the following sterna with shallow bead. Terminalia ( Figs 13–15 ): genital capsule of nigritus type, outline long-oval, gonoforcipes enlarged and apically pointed; penis valves in dorsal view as long as gonoforcipes; S8 with apical lobus ending in two roof shaped parts; S7 with proximal lobes long-triangular, distal lobes formed as long flags.

Female. Measurements (n=6): total length 5.8–6.6 (6.19) mm, wing length 4.5–5.6 (4.92) mm. Head proportions HL:HW 1.05, UHW:LHW 1.43, outline long elliptic, with pronounced malae ( Fig. 16 ). Scapi black, flagella short, black, underneath brown, partly curled. Face with characteristic long, almost rectangular white side spots on the orbits, expanded up to scapus bases. Foveae faciales long, reaching upper eye border. Clypeus CL:CW 1.35, shallow, surface shagreen and longitudinally striate, matt, anteriorly with scattered shallow punctation more distinct; supraclypeal area separated from clypeus by fine seam, upper part with a broad gradual transition to the frons. Frons and vertex with subcontiguous strong punctation. Genae longitudinally striate; occiput rounded; malae long, edges protruding. Labrum and bifid mandibles black. Mesosoma compact, dorsoventrally somewhat depressed; pilosity short, yellowish. Coloration black, pronotum black, tegulae and calli with a light spot each. Pronotum thickened, anterior margin and dorsolateral angles blunt. Mesonotum and scutellum ( Fig. 19 ) smooth and shiny, punctation moderate, dense; metanotum finer punctate; mesopleurae ( Fig. 18 ) shagreen with similar punctation as mesonotum, silky shiny, anterior margin rounded. Legs black, only bases of tibiae with white marks; wings slightly browned, venation dark brown. Propodeum ( Fig. 17 ) rounded, posterolateral humped, weakly shiny; medial area sloping, not separated from the adjacent areas, at its base with wrinkled meshes, posteriorly with less rugose sculpture; terminal area matt, only below with sharp edges, propodeal furrow shallow, shiny.—Metasoma compact spindle-shaped, coloration black. T1 ( Fig. 17 ) smooth and shiny, basally nearly without punctation, apically moderate, close punctate; following terga with fine shagreen and fine punctation; terga without fringes; fringe of last sternum yellowish.

Type material: 5 ♂, 6 ♀. Holotype: male, Russia: Tyva Republic, 60 km W Mugur-Aksy, 2270 m, 6.VIII.1987, Yu. Pesenko leg. ( ZISP). Paratypes: Russia: 1 ♀, Altai Republic, 20 km NNW Aktash, 1130 m, 10.VII.1987; 1 ♀, Altai Republic, 10 km S Tyungur, 1050 m, 23.VII.1987, all Yu. Pesenko leg. ( ZISP). Mongolia: 1 ♀, 1 ♂, Khovd Aimag, 25 km NNW Sutai, Sutai Ridge, 2100 m, 10.VI.2012; 3 ♀, Khovd Aimag, 25 km N Uench, Uench River, 1700 m, 15.VI.2012; 2 ♂, Khovd Aimag, 31 km NNE Bulgan, Ulyastain-Gol River, 17.VI.2012; 1 ♂, Govi-Altai Aimag, 17 km S Dzhargalan, Khasagt-Khairkhan Ridge, 1600–2100 m, 6.VI.2012, all A. Timokhov leg. ( IBSS, SDEI).

Etymology. This species is dedicated to Dr. Yuri Andreevich Pesenko (18.X.1944 – 23.IX.2007), a renowned expert on the taxonomy of halictid bees.

Figures

FIGURES 9 – 15. Hylaeus (Hylaeus) pesenkoi Proshchalykin & Dathe, sp. nov., holotypus male from Tyva Republic: 9 — face; 10 — propodeum and basal terga; 11 — mesopleura; 12 — mesonotum; 13 — sternum 7; 14 — sternum 8; 15 — genital capsule. Scale bar 1 mm.

FIGURES 16 – 19. Hylaeus (Hylaeus) pesenkoi Proshchalykin & Dathe, sp. nov., female paratypus from Altai Republic: 16 — face; 17 — propodeum and basal terga; 18 — mesopleura; 19 — mesonotum. Scale bar 1 mm.