Among the important predators of the European red mite, Metatetranychus ulmi (Koch), in Nova Scotia is a group of predacious mites belonging to the subfamily Phytoseiinae. There is little information in the literature on the biology of the species in this subfamily. Smith and Summers (1949) reported on the bionomics of “Hypoaspis” macropilis (Banks), and Herbert (1952) and Ballard (1953) on the life-history of Typhlodromus fallacis (Garm.).