Andrena (Aciandrena) elbensis, WOOD, 2024

WOOD, T. J., 2024, Further revisions to the Palaearctic Andrena fauna (Hymenoptera: Andrenidae), Zootaxa 5483 (1), pp. 1-150 : 79-81

Andrena (Aciandrena) elbensis spec. nov.

Figures 52A–F .

HOLOTYPE: EGYPT: Gebel Elba [Gabal Elba, inferred 22.2001 oN, 36.3321 oE], i.1937, ♀, leg. H. Priesner, OÖLM.

Description: Female: Body length: 6.5 mm ( Figure 52A ). Head: Dark, 1.1 times wider than long ( Figure 52B ). Clypeus domed, smooth and shining over its entire surface, irregularly punctate with large to small punctures, punctures separated by 1–3 puncture diameters ( Figure 52C ). Process of labrum trapezoidal-rectangular, slightly wider than long, apical margin straight. Gena slightly narrower than width of compound eye; ocelloccipital distance subequal to diameter of lateral ocellus. Foveae dorsally broad, occupying ⅔ of space between compound eye and lateral ocellus, ventrally narrowing to narrower than width of flagellum at level of antennal insertions; foveae filled with white hairs. Face, gena, vertex, and scape with short white hairs, none equalling length of scape. Scape dark, A2–12 ventrally and dorsally extensively lightened bright orange; A3 exceeding A4, slightly shorter than A4+5, A4 and A5 sub-square, shorter than long, A6–12 quadrate.

Mesosoma: Scutum and scutellum smooth and shining, with fine shagreen limited to anterior margin of scutum; scutum irregularly punctate, punctures variable, separated by 0.5–2 puncture, scutellum more irregularly punctate, punctures separated by 0.5–3 puncture diameters ( Figure 52D ). Pronotum rounded. Mesepisternum and dorsolateral parts of propodeum with fine granular microreticulation, weakly shining; propodeal triangle weakly defined, internal surface covered with fine granular shagreen, weakly shining, with weak and obscure rugae basally ( Figure 52E ). Mesepisternum with long white hairs, none equalling length of scape, scutum and scutellum with shorter scattered semi-squamous hairs, most concentrated laterally. Propodeal corbicula incomplete, weakly formed, dorsal fringe composed of whitish-yellowish plumose hairs, internal surface with scattered simple white hairs. Legs basally brownish, tarsi and hind tibiae lightened orange, pubescence light brown. Flocculus incomplete, composed of light brownish plumose hairs; femoral and tibial scopae composed of simple yellowish hairs. Hind tarsal claws without inner tooth. Wings hyaline, stigma and venation orange, nervulus interstitial to marginally slightly antefurcal.

Metasoma: Tergal discs dark, tergal margins broadly lightened reddish-brown ( Figure 52F ). Tergal discs finely shagreened to microreticulate, weakly shining, more or less impunctate, with obscure fine and scattered punctures. T2–4 apically with dense white hairbands, broadly interrupted on T2, complete on T3–4, obscuring underlying surface.Apical fringe of T5 and hairs flanking pygidial plate whitish-golden. Pygidial plate large, rounded triangular, apex slightly domed, impunctate, basal half with surface densely but shallowly punctate, punctures separated by 0.5 puncture diameters, interspaces weakly shining.

Male: Unknown.

Diagnosis. It is important to note that the current definition of the subgenus Aciandrena Warncke, 1968 is unclear ( Pisanty et al. 2022b). Revisions are ongoing (S. Bossert, T.J. Wood, G. Pisanty, unpublished data), and the diagnoses presented here should be seen in this context. Andrena elbensis can be recognised as part of the subgenus Aciandrena due to the small body size, propodeal triangle not defined by lateral carinae, surface covered by fine granular shagreen, with weak and obscure rugae basally, facial foveae narrower ventrally than dorsally but which are not so narrow as to be linear, domed and striation-free clypeus (also lacking striations on the supraclypeal area and lower paraocular areas), and hind tibial claws lacking an inner tooth. Due to the tarsi and hind tibiae that are lightened orange, the short, sparse, and semi-squamous hairs on the scutum and scutellum, and thick white hairbands on the terga it can be placed close to A. pellucida Warncke, 1974 (eastern Libya and northern Egypt), A. pavonia Warncke, 1974 (eastern Algeria and Tunisia), A. palmyriae Wood, 2021 ( Syria), and A. xera Pisanty, 2022 (southern Israel). These desert-dwelling Aciandrena have highly local distributions, and A. elbensis is strongly geographically separated from the nearest populations in northern Egypt (Borg el-Arab, A. pellucida ).

Morphological separation can be made by the interstitial nervulus (antefurcal in A. pavonia , A. xera , weakly antefurcal in A. palmyriae ), smooth and shining scutum and scutellum ( Figure 52D ; shagreened in A. pavonia , laterally shagreened and medially shining in A. xera ), head only 1.1 times wider than long ( Figure 52B ; 1.2 times wider than long in A. pellucida and A. xera , 1.3 times wider than long in A. palmyriae and A. pavonia ), and process of the labrum with anterior margin straight (deeply notched in A. palmyriae , weakly notched in A. xera ). Andrena elbensis can be further separated from A. pellucida by the facial foveae which dorsally occupy ⅔ of the space between the compound eye and a lateral ocellus and are filled with white hairs (in A. pellucida facial foveae occupying ½ space between the compound eye and a lateral ocellus, filled with brown hairs), the scutum which is irregularly punctate by punctures of variable size, punctures separated by 0.5–2 puncture diameters (in A. pellucida punctures of scutum sparser, separated by 2–3 puncture diameters), scutellum more irregularly punctate, punctures separated by 0.5–3 puncture diameters (in A. pellucida scutellum more regularly punctate, punctures separated by 1–2 puncture diameters), T2–4 with thick apical hairbands of white hairs ( Figure 52F ; broadly interrupted on T2) that obscure the underlying surface (in A. pellucida with only weak and obscure apical hairbands that do not obscure the underlying surface), and by the clypeus which is strongly domed and smooth and shining over its entire surface (in A. pellucida with the clypeus comparatively flat, only weakly domed, shiny medially but with shagreenation present laterally).

Etymology. The name is taken from the mountain Gabal Elba in south-eastern Egypt (literally “Box Mountain”) with the Latin suffix -ensis, indicating “originating from”.

Distribution. South-eastern Egypt (de facto), though this area is currently disputed and is claimed by both Egypt and Sudan.

Figures

FIGURE 1. Andrena (Avandrena) avara Warncke, 1967 sensu stricto. A. Label details; B. Habitus, lateral view; C. Face, frontal view; D. Terga, dorsal view.

FIGURE 52. Andrena (Aciandrena) elbensis spec. nov. female. A. Habitus, lateral view; B. Face, frontal view; C. Clypeus, frontal view; D. Scutum, dorsal view; E. Propodeum, dorsal view; F. Terga, dorsal view.