Hylaeus (Pumilaeus) soukontouai, Dathe, 2023

Dathe, Holger H., 2023, New insights into the taxonomy of the Hylaeus xanthostoma complex and further additions to the African Hylaeus fauna (Hymenoptera, Anthophila, Colletidae), Contributions to Entomology 73 (1), pp. 67-93 : 67

Hylaeus (Pumilaeus) soukontouai sp. nov.

Diagnosis.

This dainty species from West Africa is well recognisable by its distinct tricolouration; the curious arolia (pulvilli) deserve mention as conspicuously shiny white structures, from which one might suppose a special hitherto unknown function.

Description.

Male. N = 2. Total length 4.25-4.60 mm, wing length 3.00 mm.

Head (Fig. 64 ) long trapezoidal; HL:HW 1.07-1.10 (1.08), UFW:LFW 1.53-1.57 (1.55); scarcely hairy. Scapes slender, short, little dilated ScL:ScW 1.80-1.86 (1.83); yellowishwhite, brown streaked above. Flagella of medium length, pale yellow, brown above. Foveae faciales distinct, on vertex, converging. Mask complete, ivory: lateral spots reaching vertex above, tapering to orbits. Clypeus CL:CW 1.80-1.86 (1.70), BW:DO 0.93-0.96 (0.94); median longitudinally depressed, impression smooth; surface otherwise longitudinally wrinkled with elongate punctation, silky glossy; anterior margin horn-brown. Supraclypeal area with similar sculpture, also depressed ventrally; rounded above; apex flat in profile, not raised from frons and not set off. Frons with subcontiguous coarse punctation, shiny. Vertex shallowly convex, posterior margin shagreen, not very shiny. Occiput rounded. Facial sides increasingly set off downwards, with rounded paraocular margin. Genae narrow, longitudinally wrinkled furrowed and punctate, white pubescent. Malae conspicuously long, slightly shorter than wide. Labrum white, mandibles brown.

Mesosoma (Figs 65 , 66 ) normal, especially below with sparse white pubescence. Pronotum entirely orange, mesonotum coloured to middle, with white spots on pronoturn, calli and tegulae. Pronotum protruding, rounded laterally. Mesonotum and scutellum shagreen with strong dense punctation. Mesopleura slightly more finely and shallowly punctate, silky; omauli rounded. Legs yellow; tibiae I and II anteriorly, III basally broadly and apically more narrowly white margined; basitarsi and other tarsi white, terminal tarsomere with conspicuously developed white arolium (Fig. 67 ), claws with black tip. Wings clear, strongly iridescent; with stigma, costa and veins light brown. Horizontal part of propodeum long, surface with coarse wrinkled meshes, interspaces shiny. Terminal area ventrally and laterally with sharp ridges, finely sculptured, dull, hairy. Lateral areae posteriorly not delimited.

Metasoma (Figs 65 , 66 ) slender, long elliptic; basally orange, otherwise black. Tergum 1 shagreen, densely but moderately punctate, shiny; white lateral fringes narrow, but distinct. Following terga more finely and shallowly punctate. Depressions paler, with sparse white ciliate bands. Sterna flat, without distinctive characters. Terminalia (Fig. 37 ): distal lobes of sternum 7 forming large round membrane; proximal lobes smaller, elliptic, with fine marginal bristles. Sternum 8 with bipartite apical process, margin with short row of bristles. Genital capsule short and compact, widening distally in outline; gonoforcipes depressed apically, with long bristles on margin. Penis valves with rhombic outline in dorsal view.

Type material.

Holotype ♂, CAMEROON: Meiganga, 06°33'N, 14°15'E, 1103 m alt., 08.I.2016, Y. B. Soukontoua leg., coll. IRSNB. - Paratype 1 ♂, same data, coll. SDEI.

Etymology.

Named after the collector of the species, Yves Bertrand Soukontoua ( Ngaoundéré, Cameroon and Ghent, Belgium), latinised.

Flower visitation.

Collected on Lophira lanceolata (dwarf red ironwood, family Ochnaceae ).

Remarks.

This species does not readily fit into any of the better-known indigenous subgenera. The subgenus Hylaeus Deranchylaeus is, however, avowedly a repository for otherwise unassignable African species ( Snelling 1985), but in my opinion, there should also be positive characters, which I cannot recognise in Deranchylaeus . Rather, there seem to be some parallels in the structure of the terminalia to Deranchylaeus Pumilaeus species, such as the recently-described Hylaeus (Pumilaeus) pumilus Dathe, 2015 from Cameroon (Mindif N).

They share the membranous distal lobes of sternum 7, the apically bipartite sternum 8 and the compact genital capsule with the penis valves flat on top; the scapes are brightly coloured and the terga have terminal fringes. Interestingly, these characters are equally found in a species from Oman, which I recently described as H. (Paraprosopis) samhanicus Dathe, 2022. Similarities between the fauna of the north-eastern Afrotropics and that of the Arabian Peninsula are known ("Ethiopian Region"), but some more data would be needed before a species from West African Cameroon could be assigned to this distributional type.

Subgenus Hylaeus Deranchylaeus Bridwell, 1919

Figures

Figures 64 - 67. Hylaeus (Pumilaeus) soukontouai sp. nov., male. 64. Head, frontal view; 65. Habitus, lateral view; 66. Habitus, dorsal view; 67. Claw limb with white arolium, below in ventral view. Scale bar 1 mm.

Figures 28 - 37. 28 - 36. Hylaeus (Deranchylaeus) species, males. Terminalia. 28. H. (D.) aurantiacus sp. nov.; 29. H. (D.) xanthostoma (Alfken); 30. H. (D.) lyriformis sp. nov.; 31. H. (D.) promontorii (M. - W.); 32. H. (D.) portokalius sp. nov.; 33. H. (D.) burundis sp. nov.; 34. H. (D.) sambiensis sp. nov.; 35. H. (D.) venustus Dathe; 36. H. (D.) diastictus sp. nov. 37. Hylaeus (Pumilaeus) soukontouai sp. nov., terminalia. Rows: A. Genital capsule; B. Sternum 8; C. Sternum 7. Scale bar 0.5 mm.