Bill received his B.Sc. in 1942 from The University of Alberta where he studied under Prof. E. 0. Strickland. During the war he was a navigator for the Royal Air Force and participated in many bombing missions over Germany. After the war, he attended Cornell University and received his Ph.D. in 1952.
Bill's scientific interests were centred on the systematics of the Braconidae and lchneumonidae (Hymenoptera). Of his many scientific publications, perhaps the most significant is his revision of Apanteles s.l. (Mason, 1981), which included a reclassification of the Microgastrinae. This subfamily, with an estimated 15,000 to 25,000 species, is the most important group of lchneumonoidea in the natural and biological control of insects.
Bill was editor of the Canadian Entomologist for three years in the early sixties; also during the sixties Bill was head of the Hymenoptera section of the Systematic Entomology Unit. He was an avid collector and headed or participated in more than 20 expeditions. His numerous forays to the Arctic and his trips to Mexico and Nepal are especially important for the wealth of material that was collected. About 9% of the Hymenoptera in the Canadian National Collection was collected by Bill.
In 1986, after 38 years of service, Bill Mason retired. However, he still came to work daily, maintained a busy schedule and published regularly, even after a heart attack and by-pass surgery. Several of Bill's projects will be published posthumously. His contributions to the Hymenoptera of the World (due to be published this year) are outstanding since Bill was the principal author of the superfamily section which is the template for the remainder of the manual.
A good natured fellow, Bill was always willing to discuss any of a wide variety of subjects (entomology, climatology, classical music, theatre, etc.). He continually lifted the spirits of his friends and colleagues and is greatly missed.