Eco-éthologie des visiteurs de Lythrum salicaria L. (Lythraceae) en Belgique

Due to their ecological key position and diversity, plant-bee relationships constitutee xcellent models to understandt he processeso f food specialisationH. Ere we present a study about the visitors of Lythrum salicaria L. (Lythraceae). We estimated morphological, phenological, and behavioural features. We discuss the results by considering the food specialisation level of the visitor. In the studied populations (Hainaut, Belgium), the main pollinators were generalist bees such as Bombusp ascuorum (Apidae) andA pis mellifera (Apidae),a nd specialistb eess ucha s Melitta nigricans (Melittidae). The results show that no one of the studied species, neither the specialist, nor the generalist ones, share adaptive morphological or behavioural features that may improve foraging on L. salicaria. However, there is anarrow s1'nchronisatiobne tweent he daily and yearlyp henologieso f M. nigricans and thoseo fl,. salicaria. This could be an adaptationo fthe specialistb eet o its host plant Thus, the food specialisationo f M. nigricans, as for most specialistb ees, would be more linked to its adaptedp henologyt han to an adaptedm orphology.