Edmund M. Walker (1877-1969) joined the Department of Biology at the University of Toronto in 1904, rising to become the head of zoology in 1934. He was also Professor of entomology in the university's department of Zoology from 1906 until his retirement in 1948. Philip S. Corbet (1929-2008) was a British entomologist whose work focused largely on aquatic insects and dragonflies specifically. He co-authored and authored several books on the subject, which established him as a world expert on the order Odonata. He is also noted for his interest in biological controls as a substitute for synthetic pesticides in agriculture.