Maclear's rat is an extinct large rat endemic to Christmas Island in the Indian Ocean. It was one of two species of rat native to Christmas Island, alongside the bulldog rat. Abundant, unfamiliar with and seemingly unafraid of humans, large numbers of the creatures emerged and foraged in all directions at night. Making querulous squeaks, the rats entered the Challenger expedition's tents and shelters in 1886, ran over sleepers, and upset everything in the search and fight for food. Maclear's rat might have been responsible for keeping the population of the Christmas Island red crab in check, as recent numbers of the crab are greater than in the past. It is thought that black rats inadvertently introduced by the expedition infected the Maclear's rats with a disease, which in turn could have contributed to the species' decline. The last recorded sighting was in 1903, although it is possible that Maclear's rats hybridized with black rats. A hard tick, described as an ectoparasite of Maclear's rat, is also thought to be extinct.
Oryzomys is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat (O. palustris) of the United States and O. couesi of Mexico and Central America—are widespread; the six others have more restricted distributions. The species have had eventful taxonomic histories, and most species were at one time included in the marsh rice rat; additional species may be recognized in the future. The name Oryzomys was established in 1857 by Spencer Fullerton Baird for the marsh rice rat and was soon applied to over a hundred species of American rodents. Subsequently, the genus gradually became more narrowly defined until its current contents were established in 2006, when ten new genera were established for species previously placed in Oryzomys.
Ixodiphagus hookeri, the tick wasp, is an encyrtid wasp which lays its eggs into ticks. It seems to use a symbiotic bacteria, Wolbachia pipientis, to weaken the tick's immune system.
Powassan virus (POWV) is a Flavivirus transmitted by ticks, found in North America and in the Russian Far East. It is named after the town of Powassan, Ontario, where it was identified in a young boy who eventually died from it. It can cause encephalitis, an infection of the brain. No approved vaccine or antiviral drug exists. Prevention of tick bites is the best precaution.
Ixodes scapularis is commonly known as the deer tick or black-legged tick, and in some parts of the US as the bear tick. It was also named Ixodes dammini until it was shown to be the same species in 1993. It is a hard-bodied tick found in the eastern and northern Midwest of the United States as well as in southeastern Canada. It is a vector for several diseases of animals, including humans and is known as the deer tick owing to its habit of parasitizing the white-tailed deer. It is also known to parasitize mice, lizards, migratory birds, etc. especially while the tick is in the larval or nymphal stage.
The marsh rice rat is a semiaquatic North American rodent in the family Cricetidae. It usually occurs in wetland habitats, such as swamps and salt marshes. It is found mostly in the eastern and southern United States, from New Jersey and Kansas south to Florida and northeasternmost Tamaulipas, Mexico; its range previously extended further west and north, where it may have been a commensal in corn-cultivating communities. Weighing about 40 to 80 g, the marsh rice rat is a medium-sized rodent that resembles the common black and brown rat. The upperparts are generally gray-brown, but are reddish in many Florida populations. The feet show several specializations for life in the water. The skull is large and flattened, and is short at the front.
Rickettsia australis is a bacterium that causes a medical condition called Queensland tick typhus. The probable vectors are the tick species, Ixodes holocyclus and Ixodes tasmani. Small marsupials are suspected reservoirs of this bacterium.
Eimeria couesii is an apicomplexan parasite of the genus Eimeria that infects the intestine of the rice rat Oryzomys couesi in Mexico. It has an oocyst residuum and Stieda bodies, structures that are absent in some other Eimeria.
Amblyomma maculatum is a species of tick in the genus Amblyomma. Immatures usually infest small mammals and birds that dwell on the ground; cotton rats may be particularly favored hosts. Some recorded hosts include:
Euschoengastia peromysci is a mite in the genus Euschoengastia of the family Trombiculidae. Recorded hosts include the cotton mouse and marsh rice rat in Georgia; the northern short-tailed shrew, northern red-backed vole, northern flying squirrel, rock vole, white-footed mouse, and deermouse in Tennessee; and northern red-backed vole, southern bog lemming, masked shrew, and eastern red squirrel in North Carolina, among others.
Euschoengastia setosa is a mite in the genus Euschoengastia of the family Trombiculidae that mostly parasitizes small rodents and lagomorphs. Recorded hosts include marsh rice rat in Georgia; the deermouse in Tennessee; and the eastern red squirrel in North Carolina, among others.
Haemogamasus is a genus of mites in the family Haemogamasidae. In North America, they mostly infect rodents, in addition to other small mammals such as shrews, talpids, and Virginia opossums.
Ixodes affinis is a species of tick in the genus Ixodes. Some reported hosts are:
Ixodes brunneus is a species of tick in the genus Ixodes. It is normally a parasite of birds, but has also been recorded on the marsh rice rat.
Ixodes minor is a species of tick in the genus Ixodes. Some reported hosts are:
Ixodes texanus is a species of ticks in the genus Ixodes. It mainly infects raccoons, but has also been recorded on the marsh rice rat in Georgia.
Pterygodermatites is a genus of parasitic nematodes in the family Rictulariidae. Their life-cycle is complex. Species include:
Lankesterella is a genus in the phylum Apicomplexa. Species in this genus infect amphibians, reptiles and birds.
