EN
Life and scientific achievements (with a complete list of publications) of Dr Stefan MIELEWCZYK, a representative of the vanishing school of classical naturalists, are presented. He was a distinguished specialist in Odonata, aquatic Heteroptera and Coleoptera, however, his interests were much broader, comprising also other groups of invertebrates and vertebrates, and even water plants. His scientific legacy contains 150 publications (121 including original data). The biological and ecological study of Velia saulii and V. caprai and the still topical analysis of the odonate fauna (larvae) of selected Sphagnum-bogs in Poland belong to the greatest achievements of Dr S. MIELEWCZYK. His international recognition was also earned due to resolving of synonymy of Coenagrion lunulatum (= C. vernale), notes on dragonfly migrations, and due to comparative studies on larval morphology of some pairs of difficult to determine dragonfly species. Dr S. MIELEWCZYK was a founding member of Societas Internationalis Odonatologica. The studies and papers of Dr S. MIELEWCZYK were characterised by unusual carefulness in the application of methods, by collecting large material, a critical and detailed analysis of data and extraordinarily careful language and terminology. His great knowledge of species and their habitats was recognizable in the use of a very accurate autecological typology.