Ectoparasite diversity and Rickettsia testing of ecoparasites on feral swine (Sus scrofa) and collared peccaries (Pecari tajacu) in the Davis Mountains of Texas

Ectoparasite diversity and the possibility of vectoring Rickettsia from feral swine and collared peccaries in the Davis Mountains of Texas have not been examined. I hypothesized that feral swine and collared peccaries will host different ectoparasitic communities and that parasites will be host specific. Additionally, I predicted that at least one group of ectoparasites will test positive for a rickettsial pathogen because of the diversity of the pathogen and the species of ticks in which it thrives. Feral swine and collared peccaries were trapped using live traps baited with fermented or unfermented corn. Feral swine were euthanized in accordance with AVMA guidelines, and collared peccaries were anesthetized by the using a combination of 4.4 mg/kg Telazol and 2.2 mg/kg xylazine. A total of 25 feral swine and 29 collared peccaries were sampled. Ectoparasites were collected by visual examination and removed using fine forceps and preserved in vials of 70% Et0H for transport to the lab. Once in the lab, ectoparasites were identified by using standard taxonomic keys. Feral swine and collared peccaries harboured the hog louse (Haematopinus suis) N=341 and a neotropical tick ( Amblyomma triste) N=5, while collared peccaries hosted the peccary louse (Pecaroecus javalii) N=478. Voucher specimens of all ectoparasites were kept and deposited in the Jim V. Richerson Invertebrate Collection at Sul Ross State University. Voucher specimens of the lice were mounted onto slides in Polyvinyl Alcohol (PVA) medium, while ticks were preserved in 70% EtOH. Testing for Rickettsia was performed with real-time PCR. Three samples, one tick and two lice, were positive for the bacterial pathogen. Additional research on Rickettsia needs to be conducted to determine what species it is.