Understanding Wild Bee Abundance on Marrubium vulgare (Lamiaceae) : Biodiversity Patterns in (…)

ABSTRACT

Plant–pollinator interactions are fundamental to ecosystem functioning, particularly in semi-arid environments where floral resources are strongly limited during the summer. Marrubium vulgare L. (Lamiaceae), a widespread wild plant species in Algeria that flowers during the summer period, may therefore represent a key floral resource for wild pollinators. This study investigates the diversity, structure and temporal dynamics of wild bee assemblages associated with M. vulgare in northeastern Algeria. A total of 337 individuals belonging to 41 species, 19 genera and four bee families were recorded. Among these, Amegilla velocissima (Fedtschenko, 1875) is reported as new for the country. The assemblage exhibited a highly uneven structure, with a clear dominance of Bombus terrestris and a high proportion of rare species. Diversity indices indicated high species richness and diversity, with foraging activity peaking in the morning. The community was strongly female-biased, reflecting resource-oriented foraging behaviour. Multivariate analyses revealed that community composition was primarily structured by plant developmental stage and sex, whereas the effect of time of day was limited. Overall, these findings highlight the ecological importance of M. vulgare as a summer floral resource and its potential role in maintaining pollinator diversity in semi-arid Mediterranean ecosystems.