Ectoparasitic Arthropods Occurring on Rattus norvegicus and Rattus rattus Collected from Two Properties on the Island of Oahu, Hawaii (Acarina, Siphonaptera, and Anoplura)

A survey of ectoparasites occurring on rats was carried out from August 2006 through February 2007 on two properties on the island of Oahu, Hawaii. From the property in Liliha, a total of 167 Norway rats, Rattus norvegicus, were examined. Two species of fleas and four species of mites were collected: oriental rat flea, Xenopsylla cheopis, cat flea, Ctenocephalides felis, tropical rat mite, Ornithonyssus bacoti, domestic rat mite, Laelaps nuttalli, spiny rat mite, Laelaps echidninus, and  house mouse mite, Allodermanyssus sanguineus. From the property in Aiea, a total of 80 black rats, Rattus rattus, were examined. One species of flea, one species of louse, and two species of mites were collected: cat flea, C. felis, sucking louse, Polyplax spinulosa, tropical rat mite, O. bacoti, and house mouse mite, A. sanguineus. This is the first record of the house mouse mite, A. sanguineus, from Hawaii. Ornithonyssus bacoti and A. sanguineus were the predominant species of mites that infested both rodent species. The occurrence of other ectoparasites on the rats caught from the two sites may be affected by different rodent host and other environmental factors.