Pruinosandrena subgen. nov.

Wood, Thomas J., 2023, The genus Andrena Fabricius, 1775 in the Iberian Peninsula (Hymenoptera, Andrenidae), Journal of Hymenoptera Research 96, pp. 241-484 : 241

Subgenus Pruinosandrena subgen. nov.

Type species.

Andrena pruinosa Erichson, 1835.

Diagnosis.

This group of species was formerly placed in the subgenus Andrena Campylogaster due to the unusual character of the strongly and densely punctate mesepisternum and dorsolateral parts of the propodeum (punctures separated by <0.5 puncture diameters). However, as discussed above, Campylogaster sensu Warncke is polyphyletic and can be broken into three distinct clades ( Campylogaster s. str., Pruinosandrena , and the Andrena incisa -group). All three share the distinctly punctate mesepisternum and also an extremely long ocelloccipital distance exceeding three times the diameter of the lateral ocellus. However, separation is straightforward. The true Campylogaster have the marginal area of the terga clearly and distinctly impressed with the apical margin reflexed; the impression therefore forms a latitudinal depressed furrow. In Pruinosandrena , the marginal areas of the terga are flat, without any kind of depression. In the Andrena incisa -group, the tergal margins are flat and the mesepisternum is densely punctate, but the dorsolateral parts of the propodeum have only raised reticulation, without punctures. The propodeal triangle is also clearly delineated by raised lateral carinae, whereas these are absent in Pruinosandrena . The combination of extremely long ocelloccipital distance, dense punctures on the mesepisternum and dorsolateral parts of the propodeum, and flat tergal marginal areas is therefore unique and characterises Pruinosandrena .

Description.

Medium-sized bees (10-14 mm). Integument variable, from dark with at most tergal margins lightened hyaline-yellow to entirety of metasoma and legs red-marked; male clypeus yellow-marked in one species. Head moderately broad, 1.2 times broader than long. Gena broad, exceeding width of compound eye; ocelloccipital distance extremely long, at least 3 times diameter of lateral ocellus. Facial fovea variable, from narrow to occupying entirety of distance between lateral ocellus and inner margin of compound eye. Female scutum, scutellum, and metanotum with pubescence variable, in some species with extremely short squamous hairs, hairs longer and non-squamous in other species. Pronotum laterally with humeral angle. Mesepisternum and dorsolateral parts of propodeum densely and clearly punctate, punctures confluent to separated by <0.5 puncture diameters. Propodeal triangle without lateral carinae, internal surface with dense network of irregularly raised rugosity, thus contrasting punctate dorsolateral surface. Forewing with nervulus interstitial. Hind tibial spurs simple, not broadened basally or medially. Terga typically densely and finely punctate, punctures separated by 1 puncture diameter, at least on T2-5. Male genital capsule simple, compact, with gonocoxae apically truncate to produced into weak rounded teeth. Gonostyli apically spatulate, penis valves more or less narrow, parallel-sided, occupying less than ½ space between gonostyli.

Etymology.

The name is taken from the type species for the subgenus, A. pruinosa . The Latin word Andrena pruinosa is the feminine singular of pruinosus which means ‘frosty’, in reference to the squamous hairs of the mesosoma. The gender is feminine.

Included species.

Andrena caroli (Morocco to Israel); Andrena nilotica Warncke, 1967 (Spain); Andrena parata (Spain); Andrena pruinosa (Spain); Andrena sparsipunctata Wood, 2020 (Morocco); Andrena succinea (Morocco to Iran and Saudi Arabia). The centre of diversity is therefore Spain + Morocco, with all six species occurring here.