Nosopsyllus fasciatus

N. fasciatus characteristically look similar to other Nosopsyllus species. Like others of this genus, this species is laterally flattened, has well-developed eyes, and a rounded head. N. fasciatus has an elongated body, 3 to 4 mm in length. It has six posterior and six anterior head bristles containing three long and three short bristles. A distinguishing feature is that the dorsal bristle in the posterior row on the head is long but there is a characteristic short bristle immediately ventral to the dorsal bristle. == Distribution ==

N. fasciatus is endemic to Europe but has a worldwide distribution because of their dependence on rodents and other mammals for survival. The genus, Nosopsyllus, is native to the Palearctic Realm but has spread through human transportation to other regions of the world. The cause of the spread is due to rats escaping from the mainland to the island through boats. The islands such as the San Miguel Island and Hawaii have been inhabited by rats that carry this species. N. fasciatus is successful in spreading to new areas because it is a generalist and can colonize a new area and adapt easily. == Anatomy ==

The rat flea has three instar stages in its development. The flea larva has two pharynx chambers, where the posterior one is important for suction. After each moulting period, there is a cost of partial replacement of digestive cells for the new regenerative cells produced during this period. The larva has a two-chambered poorly-developed heart with a dorsal blood vessel. == Larval Feeding Behaviour ==

Larval N. fasciatus feed on adult fleas through attachment or on injured individuals. In the nest, larval fleas are observed to remain near adults in the debris. Larvae will attach to the posterior end of adults with their mandibles (insect mouthpart). The larva receives nutrients when the adult defecates, which contains blood within the fecal matter. The blood meal is ingested by a sucking action performed by the larvae. If the cuticle of the adult has been injured, the larvae can attack and eat the body of the injured adult. This behaviour categorizes N. fasciatus larvae as semi-predatory and displays opportunist cannibalism behaviour. == Pathology ==

Though the northern rat flea primarily parasitizes the Norway rat, Rattus norvegicus, it has occasionally been observed feeding on humans and wild rodents. It is a vector for plague and is known to be a host of the rat tapeworm Hymenolepis diminuta in South America, Europe, and Australia. This blockage is caused by a mass formation in the proventriculus. Effect on Host Parasites are known to reduce the fitness of their host. Therefore, parasitism by fleas can affect the population of the hosts. Rise in rodent outbreaks of zoonotic diseases can spread to humans, like the plague, rickettsioses, and bartonelloses. They can also transmit pathogens that cause tularemia, Q fever, trypanosomiasis, and myxomatosis. The rat flea contributes to the reemergence and cycles of some diseases, as previously mentioned. Infestation is more prevalent during the summer months and drops through the winter months. The highest infestation rate occurs during the summer because of increased activity in the mammal hosts that help spread the fleas and their disease vectors. ==Gallery==

File:Nosopsyllus fasciatus.jpg|A female and male rat flea N. fasciatus File:NHMUK010177300 A rat flea - Nosopsyllus Nosopsyllus fasciatus (Bosc, 1800).jpg|Close-up of a female slide-mounted N. fasciatus ==References==