The study of the spatial distribution of phenotypic and genetic diversity of pollinators has conservation implications since pollination is a key ecosystem function and a basis for the maintenance of biodiversity. The impact of landscape heterogeneity on the population structure of the important hoverfly pollinator, Eristalis tenax (Diptera, Syrphidae), was investigated. Allele frequencies at allozyme loci, wing traits (size and shape) and abdominal colour pattern were compared using samples from eight locations in the Durmitor National Park, Montenegro. These locations covered a broad range of altitudes and vegetation structures, from deciduous and coniferous forests to alpine meadows. From the conservation point of view, we investigated to what extent the localities in the Durmitor mountain range are connected. Results indicated a lack of population structure in the study area. A genetic clustering analyses based on Bayesian model revealed no resolution among samples, coinciding with FST estimates. Weak...