Species assemblage of wild bees (Hymenoptera: Apoidea) associated with rosemary (Salvia rosmarinus Spenn.)

This study documented 1005 floral visits by 75 species of wild bees (Insecta: Hymenoptera: Apoidea) on rosemary ( Salvia rosmarinus Spenn. syn. Rosmarinus officinalis L.) over 10 years in various forest habitats in Algeria. Bees from five families and 18 genera were identified. Apidae accounted for 42.4% of total visits, while Megachilidae constituted 30.1%. Andrenidae represented 17%, Halictidae 9.9%, and Colletidae 0.6%. Long-tongued bees predominated with 41 species and 671 specimens, compared to 30 species and 265 specimens with a short tongue; cleptoparasitic bees were observed in 6 species and 69 specimens. The peak species diversity occurred during the spring flowering of rosemary in February, March, and April, reaching 57 species in March, comprising 453 females and 133 males. Abundance declined in fall and winter. Notably, Eucera numida (117 specimens), Megachile sicula (84 specimens), Rhodanthidium siculum (84 specimens), and Eucera notata (69 specimens) emerged as the most frequent visitors to this Lamiaceae species. • This paper reports an extensive 10-year study on solitary bees in Algerian forests. • It identifies 75 species from 5 bee families and 18 genera associated to rosemary. • It reveals climate-induced shifts in bee phenology and occurrence. • Rosemary's pivotal role was highlighted as a crucial food source for solitary bees. • Findings emphasize the need to protect habitats for sustaining pollinator populations.