Raillietina (Raillietina) loeweni sp. n. (Cestoda: Davaineidae) from the Hare in Kansas, with Notes on Raillietina of North American Mammals

Abstract

Raillietina (Raillietina) loeweni sp. n. is described from the black-tailed jackrabbit (Lepus californicus melanotis Mearns) from western Kansas. A key is given for the species of Raillietina of North American mammals. Subfamily and generic emendations are made to include R. loeweni. Data are given on the seasonal and monthly prevalence of this cestode in the host population in the study area. Surveys of the parasitic helminths of hares (Lepus spp.) and rabbits (Sylvilagus spp.) in the United States and Canada have revealed Raillietina infections as follows: R. salmoni (Stiles, 1896) from rabbits in Texas (Price, 1928); Raillietina sp. from Lepus alleni from Arizona (Vorhies and Taylor, 1933); R. retractilis (Stiles, 1896) from Sylvilagus spp. from Wyoming (Honess, 1935); R. salmoni from cottontail rabbits in Alabama (Moore, 1939); R. retractilis from cottontail rabbits in California (Herman and Jankiewicz, 1943); R. retractilis from S. nuttalli grangeri, S. auduboni baileyi, S. aud. arizonae, and L. townsendi campanius; R. salmoni from S. aud. arizonae, S. floridanus, and L. cal. melanotis in Wyoming (Honess and Winter, 1956); R. retractilis from L. cal. deserticola in Utah (Grundmann, 1958); R. retractilis from L. californicus in California (Lechleitner, 1959); and R. salmoni (later Received for publication 20 September 1963. * This study was supported in part by grant No. E-1676, National Institutes of Health; by Kansas State University, Agricultural Experiment Station Project No. A-488; and by the Kansas Forestry Fish and Game Commission. Contribution No. 326, Department of Zoology, Kansas State University, Manhattan, and Zoology Series No. 357. t A portion of a dissertation presented by Monroe H. Bartel in partial fulfillment of the requirements for the degree Doctor of Philosophy in Parasitology at Kansas State University, Manhattan. Present address: Department of Natural Sciences, Moorhead State College, Moorhead, Minnesota. identified by senior author as R. loeweni sp. n.) from L. cal. melanotis in Kansas (Lyons, Hansen, and Tiemeier, 1960; Bartel, 1960). A helminth parasite survey was conducted on the black-tailed jackrabbit, Lepus californicus melanotis Meams, from January 1960, through November 1961, and June through October exclusive of September 1962, near Lakin in Kearny County, Kansas. One hundred ninety hares (70.4%) of 270 examined harbored Raillietina (R.) loeweni sp. n. Inference of the monthly infection rates of the host population by the cestode was based on the infections of ten hares collected each month. The sample of ten hares, showing no shot damage to the intestinal tract, was taken from larger monthly collections of 11 to 37 hares collected within an 11-mile radius of Lakin, Kansas, north of the Arkansas River. The hares were classified as adult or juvenile on the basis of body size, condition of reproductive organs, and the degree of epiphyseal closure of the humeri according to the method of Plenert (1962). The cestode is named in honor of Dr. S. L. Loewen, parasitologist, Tabor College, Hillsboro, Kansas. The description is based on eight gravid cestodes fixed in Ward's fixative and stained in Delafield's hematoxylin. Additional specimens were observed fresh or cleared in lactophenol. Egg pouches, teased from fixed gravid proglottids, were measured and counted. The size of eggs and oncospheres was determined from eggs teased from living proglottids. Living oncospheres were stained with 1 : 10,000 neutral red or 1: 5,000 brilliant