This issue celebrates the 75th birthday ofÿ Dr. Lubom?r Masner, a source of knowledge, enthusiasm, and inspiration for systematic entomologists in all fields, but especially for students of Hymenoptera. His unflagging dedication to the study of the parasitoid wasps of the superfamilies Proctotrupoidea, Platygastroidea, and Ceraphronoidea has completely transformed our understanding of the richness and evolutionaryÿ history of these insects. His zeal and innovation in collecting have not only dramatically enhanced the basis for our understanding of hymenopteran diversity, but also contributed to the development of the Canadian National Collection of Insects into one of the premiere systematic entomology research institutions in the world. Twenty-six authors have contributed to this volume in 17 papers on the systematics of the families Braconidae, Ceraphronidae, Chalcididae, Eucharitidae, Eupelmidae, Eurytomidae, Figitidae, Mymaridae, Platygastridae, Vespidae, and Xiphydriidae. Six new genera and 33 new species are described, encompassing fossil material as well as species from the Neotropical, Afrotropical, Oriental, and Australasian regions. A short biography of Dr. Masner is accompanied by a bibliography of his scientific papers, a list of taxa he has described over 55 years of research, and a list of taxa named in his honor.