Pollination Efficiency of <i>Apis mellifera</i> (Linnaeus) and <i>Eucera eucnemidea</i> (Klug) in two Brassica Species in Algeria

Pollinators play a crucial role in agricultural productivity, enhancing both the quantity and quality of crop yields. This study investigated the diversity, foraging behavior, and pollination efficiency of insect visitors in rapeseed (Brassica napus Linnaeus) and turnip (Brassica rapa Linnaeus) crops across two regions in Algeria: Constantine and Chelghoum El Aid. Over three flowering seasons (2021-2024), 20 insect species were recorded, with Hymenoptera as the dominant order. The European honey bee (Apis mellifera Linnaeus) and the wild bee Eucera eucnemidea (Klug) together accounted for more than 95% of total floral visits. While A. mellifera showed higher visitation frequency, E. eucnemidea demonstrated greater pollination efficiency through higher pollen deposition and faster movement between flowers. Open pollination significantly improved yields, increasing seed weight by up to 51% in rapeseed and tripling it in turnip compared to self-pollination. These findings emphasize the vital role of pollinators, particularly E. eucnemidea, and support the implementation of sustainable practices such as habitat conservation, strategic placement of honey bee colonies, and reduced pesticide use to ensure pollinator health and agricultural productivity in Algeria.