Andrena schencki Morawitz 1866

Andrena schencki Morawitz, 1866 Conservation status EN Distribution This species is found in Europe, in the Middle East and as far east as Turkmenistan (Tomozei 2014). Andrena schencki was widespread in Belgium during the first half of the last century, but is now limited to the Ardenne and the Belgian Lorraine (Pauly 2024). Given its preference for oligotrophic grasslands, this species may benefit from the restoration of extensive agricultural practices and the reduction of nitrogen inputs. Notes This species is described as associated with oligotrophic grasslands (Westrich 2018). The only specimen we collected was found in a mesic grassland with an intermediate nutrient concentration. This observation suggests the species may occupy a broader ecological niche and that extensively managed grasslands, even with moderately elevated nutrient levels, can support its habitat requirements. Nests are typically excavated in compact, sparsely vegetated soils, such as pathways, although they can occasionally be found in lighter soils. Nests may be solitary or form aggregations of up to 100 individuals (Westrich 2018). Females are polylectic, foraging on flowers from at least five plant families: Asteraceae, Cornaceae, Brassicaceae, Dipsacaceae, and showing a preference for Fabaceae (Radchenko 2015). Andrena schencki is univoltine, flying from April to July (Peeters 2012). Diagnosis Andrena schencki is one of the few Belgian Andrena characterised by a red-marked metasoma (Fig. 4). Both sexes are relatively large, measuring over 10 mm. Females lack plumose hairs on their hind tibiae and possess a shiny, strongly punctuated and short-haired second tergite, along with a dull and densely punctate clypeus. Males have a pale clypeus and pale para-ocular areas, as well as elongated mandibles that cross apically when closed (Wood 2023).