1996-present. Honorary Research Associate, Systematic Entomology Section, Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, ON. (systematics of proctotrupoid wasps)
1969-1996. Research Scientist, Crop Protection Program, Centre for Land and Biological Resources Research, Agriculture Canada, Ottawa, ON. (systematics of proctotrupoid wasps)
1968-1969. NRC Postdoctoral Fellow, Simon Fraser University, Burnaby, BC. (systematics of proctotrupoid wasps)
1964-1965. NRC Postdoctoral Fellow, Biocontrol Laboratory, Agriculture Canada, Belleville, ON. (platygastrid parasitoids of cone pests)
1957-1964. Institute of Entomology, Czechoslovak Academy of Sciences, Prague, CZ. (biocontrol of forestry pests, systematics of proctotrupoid wasps)