The genus Andrena Fabricius, 1775 (Hymenoptera, Andrenidae) in a Mediterranean biodiversity hotspot: community-wide relationships with plants and description of three new species

Evolutionary and ecological factors underlying the extensive, fast diversification of the species-rich bee genus Andrena (Andrenidae Latreille, 1802) are of general interest and require elucidation. Progress in evolutionary and ecological understanding of hyperdiverse Andrena assemblages, however, has been hindered in parts of the world where the genus reaches its highest species richness. The lack of well-established taxonomic resources has precluded studies on resource use and patterns of reciprocal relationships with plants which could potentially shed light on drivers of Andrena diversification.

This paper presents an analysis of community-wide relationships between plants and Andrena bees in a western Mediterranean biodiversity hotspot (Cazorla mountain range, southeastern Spain). By combining information on pollinator composition of the regional community of entomophilous plants (292 species) with a state-of-the-art taxonomic treatment of the regional assemblage of Andrena (89 species), we assess here the distribution across the plant phylogeny of floral resources utilized by Andrena; the quantitative patterns of mutual dependence between species of plants and Andrena; and the completeness of our regional sampling of Andrena species.

Three new species of Andrena from the study region, which were discovered in the course of the field study, are also described and illustrated: A. officinalis Wood, sp. nov., A. rostro Wood, sp. nov., and A. cazorlae Wood, sp. nov.