Entomology: PHTHIRAPTERA 1
Kingdom: Animalia, Phylum: Arthropoda
Subphylum: Hexapoda: Class: Insecta: Order: Phthiraptera = Anoplura
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General Summary of Phthiraptera
The evolution of these lice with their hosts is closely paralleled. They are small wingless insects. Their mouthparts are adapted for piercing the skin and sucking the blood of their hosts. The eyes are poorly developed or absent. The legs are very short and the single-jointed tarsus carries a large curved claw that is well adapted for clinging to the host. The thoracic segments are fused, and a flattened abdomen of nine segments has large pleural areas allowing the body to swell on feeding. There is no metamorphosis.
The stylet complex can be extended so as to make contact with the skin. Into the wound is poured the salivary fluid that keeps blood from coagulating, and the mouth funnel is plunged in to enable the blood to be sucked up by the pharyngeal pump. During development the 1st maxillae unite to form the dorsal stylet, the ventral being formed by the labium. A pair of mandibles is also present but these are undeveloped.
Humans develop a rash from the salivary secretions. They are also vectors of Rickets and Relapsing Fever. Pediculus humanus, the body louse is associated with the spread of many diseases, such as typhus and relapsing fever. This insect also transmitted the disease known as Trench Fever, which reduced Napoleon's Army and was prevalent in all war areas during World War I (see ent79):
The group as a whole includes the most important vectors of Typhus Fever. During World War II, DDT treatment of the Italian population was required to rid it of a louse epidemic. Although the crab louse is not a disease vector, it can be contacted either through bodily contact or indirectly from bedding, etc. It is known to attack only humans and wild gorillas in Africa.
Sucking lice rank number one in livestock pests with three different species attacking cattle, two species goats and one species hogs.
Please also view Medical Importance
Cleanliness is of the utmost importance in keeping down infestations of sucking lice. For livestock it is important to maintain the animals in a healthy state. DDT and Rotenone applied twice a year in autumn and spring has been effective for the control of both adults and eggs.
Examples of beneficial species occur in almost every insect order, and considerable information on morphology and habits has been assembled. Therefore, the principal groups of insect parasitoids and predators provide details that refer to the entire class Insecta. These details are available at <taxnames.htm>.