PEDICULUS 



757 



Pediculus corporis de Geer, 1778. 



Synonyms. — P. humanus Linnaeus, 1758; P. humanus var. 2 

 Linnaeus, 1766; P. humanus var. corporis de Geer, 1778; P. vesti- 

 menti Nitzsch, 1818; P. corporis Csiki, 1904. 



Definition. — Pediculus usually dirty-white in colour, thorax 

 only slightly narrowed anteriorly, abdominal segments not very 

 distinctly defined and not well festooned laterally. Thumb-like 

 projection on the tibia without a spine. Habitat, homo. 



Remarks. — This louse lives in the folds and seams of the clothes. 



Morphology. — It is larger than P. humanus, and has an oval, 

 elongated head, with large antennae. The thorax is more segmented 

 than in P. humanus, and the legs more developed, with larger claws. 



Life- History. — It lays seventy to eighty eggs, measuring 07 to 

 0*9 millimetre, in the seams of the clothing, which hatch in three to 

 four days, and become mature in fifteen to eighteen days. 



Pathogenicity. — It is a carrier of typhus fever, trench fever, 

 and certain forms of relapsing fever. 



Treatment. — Boil or steam the clothes in a sterilizer at 212° F. 



Genus Phthirius Leach, 1815. 



Pediculidae with the anterior legs weak, armed with large short 

 claws; abdomen broad and short, with first to fifth segment so 

 strongly compressed that 

 the stigmata appear to lie 

 in one segment. Fifth 

 to eighth segments with 

 lateral tooth-like pro- 

 cess, of which thet wo last 

 are long. Habitat, homo. 



Phthirius pubis Lin- 

 naeus, 1758. 



Synonyms. — Pediculus 

 pubis Linnaeus, 1758 ; 

 P. inguinalis Reichard, 

 1759 ; Phthirius inguina- 

 lis Leach, 1815; P. tahe- 

 scentium Alt, iSiS ;P. pu- 

 bis Kiichenmeister, 1855. 



Remarks. — P. pubis is the pubic or crab-louse, and is more common 

 on men than on women. It usually infests the pubic hairs, but may 

 also be found on the eyelashes and on the eyebrows. 



Morphology. — The body in general is flat and broad, with a 

 rounded head bearing antennae with five segments, and two small 

 eyes. There is a neck. The broad, flat thorax is merged into the 

 abdomen, and carries three pairs of legs, of which the anterior pair 

 is slender, and possesses a straight claw suitable for walking, and 

 the two posterior pairs have claws suitable for chnging. 



Fig. 371. — Phthirius pubis Linn^us: 

 Female. (X25.) 



