\u3ci\u3eHymenolepis robertrauschi\u3c/i\u3e n. sp. from Grasshopper Mice \u3ci\u3eOnychomys\u3c/i\u3e spp. in New Mexico and Nebraska, U.S.A.

From 1989 through 1998, a total of 358 grasshopper mice were collected and examined for helminth and protistan parasites from several habitat types on the Sevilleta Long Term Ecological Research (LTER) site in New Mexico, U.S.A. Of these, 205 individuals were identified as Onychomys leucogaster (Wied-Neuwied 1841) and 153 individuals were classified as O. arenicola Mearns 1896. Many individuals of Onychomys were infected with a new species of Hymenolepididae (Hymenolepis robertrauschi), which is herein described, illustrated, and compared with all species of Nearctic Hymenolepis s. str. Hymenolepis robertrauschi was found in 26% of the individuals of O. arenicola and 18% of the individuals of O. leucogaster, giving an overall prevalence of 22% in the individuals of Onychomys from New Mexico. The intensity of H. robertrauschi in Onychomys ranged from one to 33 individual cestodes. The number of individuals of H. robertrauschi found in each individual of Onychomys examined was generally between one and five; only seven of the 79 infected Onychomys harbored more than five individual cestodes. In Nebraska, during August 2012 and July-August 2013, 14 specimens of O. leucogaster were examined for helminths; H. robertrauschi was found in four of those individuals