Hylaeus (Pumilaeus), 2015

Dathe, Holger H., 2015, Studies on the systematics and taxonomy of the genus Hylaeus F. (9) Supplement to the taxonomy and distribution of Afrotropical Hylaeus F. species (Hymenoptera: Anthophila, Colletidae), Beiträge Zur Entomologie = Contributions to Entomology 65 (1), pp. 9-26 : 23

Subgenus Hylaeus (Pumilaeus) subgen. nov.

Type species: Hylaeus pumilus spec. nov.; loc. typ.: Cameroon, N Mindif, bord Mayo Boula .

The relevant characters are explained in more detail in the following species description. Which of them actually are diagnostic of the group depends on the possible discovery of other related species. Currently there is no similar species known in the region.

Description: This subgenus is characterized mainly by the terminalia of the male ( Fig. 25 ). The genital capsule is oval in outline, with penis valves in the dorsal view apically broadly rounded, the apical bristles long and converging. Sternum 7 is unique: with distal lobes expanded into a pair of convex bubble-like surfaces without clear subdivision into proximal and distal parts, and without bristles. Sternum 8 is a little reminiscent of certain Palaearctic Hylaeus (Nesoprosopis) species: with apical lobus prolonged, narrow, apically divided into two round lamellae with fine marginal bristles.

According to the identification keys by SNELLING (1985), MICHENER (2007) and DATHE (2014) , one can exclude the subgenera Alfkenylaeus , Cornylaeus, Metylaeus , Nothylaeus and Prosopisteron. So far Pumilaeus subgen. n. shows a number of exclusion criteria to those subgenera, but few special features of its own: (1) The sculpture of the mesosoma is regular, not coarse, with fine to moderate, dense punctation, (2) occiput and propodeum are rounded, (3) the mandibles bifid. But among the known species, Pumilaeus subgen. n. also delimits sufficiently clearly from Deranchylaeus : On the head, (4) the vertex is narrow and backward sloping with rounded transition; (5) the foveae faciales are extended to the vertex, where they converge strongly. The antennae are short. (6) The supraclypeal area is very flat and only faintly raised above the curvature of the face in lateral view, its lateral edges are without sharp ridges; above it merges relatively broadly into the vertex, wherein the females have in addition to the median furrow four to five striking parallel grooves on each side. Finally, (7) the very short, rounded pronotum, not expanded forward, distinguishes this taxon from the known Deranchylaeus species.

Figures

Figs 22–25: Male terminalia: metasomal sterna 7 and 8 (S7, S8), genital capsule. – 22 Hylaeus (Alfkenylaeus) euphorbiae spec. nov. – 23 Hylaeus (Cornylaeus) adamauanis spec. nov. – 24 Hylaeus (Deranchylaeus) haladanius spec. nov. – 25 Hylaeus (Pumilaeus) pumilus spec. nov., S7: left ventral view, right dorsal view. – Scale 0.2 mm.