Results of a Survey of Calyptrate Flies of Medical Importance Conducted at London, Ontario During 1953

Abstract

The writer (Judd, 1954) conducted a survey of mosquitoes at London, Ontario and its vicinity during 1952, and the information derived from this survey has since been used by the 'City of London in organizing a program of mosquito control. As a second contribution to the study of flies of medicail importance in the vicinity of London it was decided to conduct a survey of calyptrate flies such as house flies, stable flies, blowflies, flesh flies, cluster flies and latrine flies during 1953. These are all flies of comparatively large size and they commonly enter houses, restaurants, public buildings, summer cottages and resort buildings. Many of them are habitually attracted to and breed in garbage, dead animal material, dung of animals and other wastes. Several of them have been known for many years to, be associated with the transmission of important diseases of humans and animals such as typhoid fever, dysentery, cholera and anthrax. Invasions of the ma'ggots of some of the species in wounds, diseased tissues and even in healthy tissues of animals and humans have frequently been observed. More recently their possible role in the dispersion and transmission of poliomyelitis virus has been investigated (Melnick, 1949; Melnick and Ward, 1945; Toomey et al., 1941; Trask and Paul, 1943; Trask et al., 1943). Consequently a program of control of these flies is desirable and information derived from a survey of flies occurring in a chosen locality can prove of value in establishing such a program. Surveys of flies have been made in several localities in North America, e.g. New York, N.Y. (Williams, 1954), New Haven, Conn. (Power et al., 1943), Stone Mountain, Ga. (Dodge and Seago, 1954), Madison, Wisc. (Dicke and Eastwood, 1952), Rockford, Illinois (Melnick, 1949), Savannah, Ga. (Quarterman et al., 1949), Charleston, W. Va. (Mail and Schoof, 1954) and, concurrently, in localities in Arizona, Kansas, Michigan, New York and West Virginia (Schoof and Savage, 1955). Acknowledgment.-The writer wishes to express his gratitude to Mr. J. B. Hartley who aided throughout the course of the survey in collecting, identifying, sorting and counting insects and in recording data.