Thesis--University of Illinois. / "Contribution no. 277 from the entomological laboratories of the University of Illinois." Includes bibliographical references (p. 116-119).

Digitized by Kansas State University Libraries

No description available.

Inaug.-diss.--Berlin. / Lebenslauf. "Literaturverzeichnis": p. [40]-41.

The Uninta ground squirrel, Spermophilus armatus Kennicott, is the most abundant diurnal rodent in the Wasatch Mountains at the 7,000-9,000 foot level particularly in the campgrounds and picnic areas. Contact between man and the Uninta ground squirrel may be hazardous inasmuch as the causative agent of plague has been isolated from S. armatus and its flea parasites (Public Health Reports, 1937, 1938a, 1938b; Meyer, 1938; Byington, 1940; Allred, 1951; and Beck, 1955). Since these fleas are vectors of sylvatic plague and potential vectors of human plague, detailed knowledge about their population dynamics is desirable.

Fleas of the genus Foxella Wagner, commonly known as "gopher fleas," have various species of the mammal genus Thomomys Weid Neuweid in the Western United States as their hosts. Some workers maintain there are at least two species of fleas while others consider that all gopher fleas are of one species.

Knowledge of the bionomics of plague vectors, es-pecially factors which influence life history, host pre-ference, and fluctuations of flea populations, are basic to an understanding of plague ecology. Orchopeas leucopus (Baker), an ectoparasite of cricetid rodents such as Peromyscus maniculatus (Wagner), and Peromyscus truei (Baird), is a vector of plague in the western United States (Holdenried and Morlan, 1955). In a study of nine biotic corrnnunities in the Utah portion of the Great Basin, P. maniculatus was the most abundant rodent in seven of the biotic corrnnunities (Olsen, 1966). Because of the ubiquitous nature of P. maniculatus an interchange of its fleas with other animals might be expected, but this does not seem to be so with O. leucopus, as it is found mostly on cricetid rodents of the genus Peromyscus, and only occasionally on other rodents, thus indicating some degree of host specifi-city. There are many published reports which indicate that some ectoparasites prefer one species of host over another. Evans and Freemen (1950), Hopkins (1957), Holland (1958), and Wenzel and Tipton (1966) suggested that insights into host suitability with reference to ecology and physiology of the majority of flea species are largely unknown. Most host preference studies have not dealt with flea species endemic to the western states.

No description available.

Plague outbreaks in the past have been disastrous where domestic rats and their fleas of certain species were common. Plague has been known to occur in most parts of the world (Robertson 1923), and has occurred as human epidemics for many centuries (Dubos 1948).

The first hemoflagellate was discovered by Valentine in 1841; two years later Gruby established the genus Trypanosoma for a flagel-late in the blood of frogs, and in 1879 Lewis in India described Try-panosoma lewisi Kent of the rat (Belding, 1965:141).