127 



would do well always to be provided with a good supply of 

 pyrethrum or similar insect powder. A little of this 

 substance, dusted over sheets and pillows, may provide 

 against attack by both bed bugs and fleas, and aid in 

 procuring undisturbed rest. 



lice. Hemiptera. 



There ai^e three species of parasitic Hemiptera known 

 as lice, which are peculiarly adapted to life on the human 

 subject. These are the head louse (Pediculus capitis, 

 De Geer), the body louse (Pediculus vestimenti, Leach) and 

 the crab louse (Ph thirius inguinalis, Leach). The first two 

 of these are similar in appearance and in habits. The 

 former, however, lives only in the fine hairs of the head, the 

 latter secreting itself in the clothing. The crab louse is 

 smaller and broader in proportion, than the others, and it 

 inhabits the coarse hairs of other parts of the body than the 

 head. 



The eggs of lice, commonly called nits, are small, 

 whitish, ovoid objects attached to the hairs, or, in the case of 

 the body louse, secreted in the folds of the clothing. 



The remedies to be used for the control of these para- 

 sites are, first, cleanliness, and second, the destruction of the 

 insects by means of a contact poison, or in the case of the 

 body louse, by the fumigation of the clothes. The contact 

 poisons to be used include insect powder, oils and oily 

 mixtures, mercuric ointments and sulphur ointment. 



The bodv louse occurs chieflv among armies and in 

 prisons. Infested clothing may be subjected to baking or 

 to treatment with the fumes of sulphur or tobacco. If this 

 treatment is repeated two or three times at intervals of 

 a few days, and strict personal cleanliness is maintained, the 

 attack by this insect will probably be overcome 



THE BLOOD-suckixg COXE NOSE (Conorhinits sanguisuga, 



Lee). Hemiptera 



This insect, which is sometimes called the bi^ bed-bug 

 (Fig. 141), belongs to a family of Hemiptera which includes 



