Conserving wild bees for crop pollination: efficiency of bee hotels in Moroccan cherry orchards (Prunus avium)

Food production is highly dependent on pollination services provided by insects; 75% of the leading global food crops need animals for successful production. Pollinators, including managed and wild bees, are declining in many parts of the world. The loss of natural habitats providing nesting sites is considered as one of the main factors driving the decline of crop-visiting wild bees. The researchers had hypothesized that providing bee hotels in cherry orchards may be a useful strategy to support visitors of cherry flowers (Prunus avium). To test this hypothesis, observation was made on the attractiveness of bee hotels to wild bees in cherry orchards in Sefrou Province (Morocco). Bee hotels were installed at the border of two cherry orchards. Surrounding landscapes were described and pollinator communities were observed and sampled within bee hotels, cherry flowers, and also within the surrounding landscape. Bumblebees (Bombus spp.), Mason bees (Osmia spp.), sand bees (Andrena spp.), and sweat bees (Lasioglossum spp.) are the most abundant genera representing almost two-thirds of all wild bee visitors of cherry trees. Mason bees (Osmia spp.) are the most abundant bees nesting in bee hotels with almost three-quarters of all insects recorded. Bee hotels could therefore be used to sustain or even increase cavity-nesting bees visiting cherry orchards in Morocco.