54 



Insects and Disease 



they occur in such numbers as to make great 

 masses of sores. 



On account of being such general feeders they 

 are difficult to control, but some relief may be ob- 

 tained by keeping the houses and barns as free as 

 possible from dirt and rubbish and by sprinkling 

 the breeding-places of the pest with pyrethrum 

 powder or carbolic water. Those that gain an en- 

 trance into the skin should be cut out, care being 

 taken to remove the insect entire. 



BEDBUGS 



In the order Hemiptera, or the true " bugs' ' in 

 an entomological sense, we find a few forms that 

 may carry disease. The bedbug (Fig. 35) (Cimex 

 lectularis) has been accused of transmitting plague, 

 relapsing fever and other diseases. Very recent 

 investigations show that the common bedbug of 

 India (Cimex rotundatus) harbors the parasite 

 that causes the disease known as kola azar, and 

 there is no doubt that it transmits the disease. 



LICE 



The sucking lice (Fig. 36) which also belong to 

 this order are suspected of carrying some of these 

 same diseases. It is thought that the common 



