There are 1000 species flea around the world, and still there is many of unknown species. It is thought to have differentiated from biting kind, but there is no fossil evidence on (lice live in the fur of mammals as biting acids similar external parasites, but it is not known at all from birds unlike flea on earth) .
Fleas parasitic on humans are two types of pubic lice Phthirus pubis (2 subspecies of the body louse Pediculus humanus corporis and head louse Pediculus humanus humanus in some cases) and body lice of this. These are species of these same worldwide species pan-world species (Cosmopolitan), are parasitic on the human race.
It's impression flaccid appearance is translucent body length is several mm or less many, it has a sturdy body wall structure that is resilient, such as rubber. Body Type resemble biting kind, but the head is small, mouthparts is deformed significantly, become a 吻針 sharp composed of tubular Shitahari, salivary tongue, lower lip from the needle, the pharynx pierces the skin of the host it I will at a certain blood-sucking pump. Mouthparts is drawn in the head when not in use. Antennae consisting of Section 5, but some of Section 3 rarely. It has a compound eye pair, but there is a tendency to degenerate, some species lacking species and the light receiving lens or plaques of a simple pair. Section 3 of the chest is always healing, wings are degenerate. Leg is deformed so that it is suitable to grab the hair, Ten-bushi become Section 1. There is one nail on its tip. The abdomen consists of verse 9, ovipositor is degenerate, it has become a two valves.
It becomes egg → larva → adult in incomplete metamorphosis. One end is sticking to the hair of the host of a substance like glue that is issued from the base of the ovipositor eggs. There is a lid with a ventilation hole called pores projections to the free end side, larvae hatch from this egg lid. Shape and adults are very similar larvae, I vampire in both sexes than immediately after hatching. Larvae become adult in about 1-2 weeks through the third instar. After mating, 8-10 pieces one day body lice, adults lay eggs of about 100 to 200 or so of my life. Slightly less 1-4 pieces a day, pubic lice lay eggs about 40 or so of my life. Adult body louse is about three weeks about adult about a month, the pubic louse life.
Because lice have adapted very well to the particular mammal also morphological also physiological, host range is limited. The parasitic if and only host of several of the same genus or one, specific, lice is one rodent of some (human, bovine, and only lice one kind of parasitic to the host of one ordinary 1 receiving a lice infestation the two, which is exceptional). This is in contrast and very fleas that you migrate easily often host apart of the system is known. I also considered each genus of lice because it has a parasitic relationship that corresponds to the family of closely related to it or a particular family of mammals, lice and host and co-evolution. The eutherian, and lice, not parasitic Tanana-rui, the marsupials bat first, Xenarthra, elephant eyes, pangolin eyes, Order Sirenia, cetacean.
Relationship with humans
Lice and fleas sucking and parasitic on humans together, in order to give the itch, it is treated as a pair well. However, fleas are considered one of the insects that go through complete metamorphosis pupae, and is a system that has evolved mammals from parasitic insects of the system close to the Mecoptera a relatively primitive. In contrast, among the insects of incomplete metamorphosis that does not undergo a pupa, belongs to Psocodea closely related to Hemiptera lice, I differ greatly in systematic. In addition, seed starvation resistance is often strong for a drink that is also species that leave the host often, lice spent in the host body table life lacking usually starvation resistance.
As life history, flea larvae is to grow, such as inside of the dust of the corner of the room, lice live in host on lifelong. Therefore, change of clothes and bathing if done frequently, lice will not Kurase, but fleas should not be necessarily so, to continue living. So I said, "The poor lice, fleas get rich" also.