Human flea

The human flea ( Pulex irritans ), illustration of Medical and Veterinary Entomology (1915 )

The human flea ( Pulex irritans ) is an insect of the order parasitierendes of fleas ( Siphonaptera ).

Features

The human flea is about 1.6 to 3.2 mm in size and wingless. His well-developed hind legs enable it jumps up to 30 cm high and 50 cm wide. As skin he has a very tough layer of chitin, which is colored dark brown.

As evident from the name, this flea species specializes primarily on humans, that is, they have compared to other flea species a high host specificity. However, they occasionally infest the people close to animals, such as dogs and cats.

Occurrence

The actual human flea has become rare in Central Europe. Much more common are people from the dog flea (Ctenocephalides canis) or cat flea (Ctenocephalides felis) infected.

Nutrition

As a food it sucks blood, but can also make do up to a year without a meal. For the bite of warm humid regions are preferred to the body. A single flea can usually litter the night in a short time the whole body with stitches. Normally, the flea per day takes a blood meal. He or she shall, if possible, often to twenty times its own weight. Part of the digested blood is shortly thereafter excreted.

The flea bites are occasionally arranged in a row; we also speak of flea street.

Development

The development of the human flea runs the stages egg, larva, pupa and imago. Such a cycle usually lasts from a few weeks to 8 months.

Oviposition

The first copulation takes place about 8 to 24 hours after ingestion. A day after mating female fleas begin laying eggs. A female lays approximately 50 eggs that are placed randomly on the host organism per day. They are soft, oval, bright, only about ½ mm in size and have no sticky outer shell, which is why they can always depart from the host body.

Young larvae

The young larvae hatch about 2-14 days after oviposition and hide, preferably in carpets, floors, especially at the corners and the wall regions near the heater, in upholstered furniture, pillows, mats and mattresses. The angedaute of a flea and again precipitated blood serves to 5 mm long, white, threadlike larvae as food because they can not suck.

Harmful effect

As typical reaction of a flea stitch arise in humans small papules. These have a red color, are usually hard, slightly elevated and exert a more or less intense itching from. By scraping the papules can lead to secondary infections.

Human flea as disease carriers

The human flea can transmit occasionally during blood feeding by mechanical means, the causative agent of typhus and the bubonic plague. Transmission occurs through contact of flea feces or contaminated flea body ( proboscis ) with the stab wound. Furthermore, human fleas intermediate hosts for different tapeworm species such as the cucumber tapeworm his core ( Dipylidium caninum ) and upload them too.

A group of researchers at the University of Marseille to Didier Raoult believes that with change of host and the human flea next to the head louse ( Pediculus humanus capitis) and body louse ( Pediculus humanus humanus ) as vectors of plague comes into question, since all these parasites mentioned can record plague bacteria.