''Paraceras melis'', the badger flea, is an external

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

of the

European badger The European badger (''Meles meles''), also known as the Eurasian badger, is a badger species in the family Mustelidae native to almost all of Europe. It is classified as least concern on the IUCN Red List as it has a wide range and a large stab ...

(''Meles meles''). It has also been found on the fox (''Vulpes vulpes''), the

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

(''Canis familiaris''), the

cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

(''Felis catus''), the

European polecat The European polecat (''Mustela putorius''), also known as the common polecat, black polecat, or forest polecat, is a species of mustelid native to western Eurasia and North Africa. It is of a generally dark brown colour, with a pale underbell ...

(''Mustela putorius''), the

mole Mole (or Molé) may refer to: Animals * Mole (animal) or "true mole", mammals in the family Talpidae, found in Eurasia and North America * Golden moles, southern African mammals in the family Chrysochloridae, similar to but unrelated to Talpida ...

(''Talpa europaea'') and the

fallow deer ''Dama'' is a genus of deer in the subfamily Cervinae, commonly referred to as fallow deer. Name The name fallow is derived from the deer's pale brown colour. The Latin word ''dāma'' or ''damma'', used for roe deer, gazelles, and antelopes ...

(''Dama dama'').

Description

The badger flea, like other

flea Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by ingesting the blood of their hosts. Adult fleas grow to about long, a ...

s, is a small, dark brown wingless insect with a tough, chitinous cuticle. Its body is flattened laterally and it has mouthparts designed for sucking the

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

of a badger.

Biology

Like other fleas, the badger flea has a

life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring * Life-cycle hypothesis ...

consisting of an egg, a

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

l, a

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...

l and an adult stage. A mature female flea has to have had a meal of blood before she starts to reproduce. After mating, the eggs are laid and often fall to the floor of the sett. The larvae that hatch out feed on organic debris and when fully developed, they weave cocoons and pupate. They remain in this state for several weeks, often being stimulated to emerge by warmth, vibrations or a raised level of carbon dioxide which indicates that a potential host is nearby. The newly hatched flea's primary aim is to find a host, have a meal of blood and reproduce. The badger flea is the vector of '' Trypanosoma pestanai'', the causal agent of a protozoan disease of badgers that has been found in badgers living in Portugal, France, England, and Ireland.

Behaviour

Badgers spend much time grooming in an effort to dislodge parasites. Individuals concentrate on their undersides while social grooming occurs with one individual grooming another on its dorsal surface. Fleas try to avoid the scratching, retreating rapidly downwards and backwards with the lie of the fur. This is in contrast to fleas away from their host which run upwards and jump when disturbed. The grooming seems to disadvantage the fleas rather than merely having a social function. Researchers have found that when separated from their host, badger fleas jump repeatedly in an effort to reconnect. Many voided their gut contents which enabled them to leap significantly further. If they failed to find a suitable host they moved towards the light (the

sett A sett or set is a badger's den. It usually consists of a network of tunnels and numerous entrances. The largest setts are spacious enough to accommodate 15 or more animals with up to of tunnels and as many as 40 openings. Such elaborate setts ...

entrance) before becoming quiescent. This put them in a position to intercept a badger if one entered the sett. They were stimulated into further bouts of leaping by an increase in the level of

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

and jumped towards the source of the gas. In a research study they were found to respond to exhaled air by running and jumping in its direction. The most vigorous response was found to be made to a combination of a carbon dioxide source, a piece of dark-coloured card and movement in their vicinity. It was found that 50% of fleas were still alive after 35 days of separation from the host and, as badgers have a habit of moving between different setts, they would not avoid reinfestation by fleas if they returned to an empty sett within a few weeks.

References

External links

{{Taxonbar, from=Q10616968 Ceratophyllidae Insects of Europe