Insects and Human Health 543 



the tiger mosquito. This is the carrier of the yellow fever 

 virus. It is therefore important to be able to recognize it. 

 Its habitat is usually in the tropical and subtropical regions ; 

 but it is often transported into the colder climates of the tem- 

 perate zones. It is remarkably domestic in its habits and in- 

 stincts. Its breeding places are much the same as those of the 

 common Culex. 



'The color and markings of the Stegomyia (Fig. 163) are char- 

 acteristic. The body, abdomen, wings, and legs are brilliantly 

 marked with black and white stripes. 

 It is thus conspicuous among its more 

 somber- colored relatives. Although it 

 feeds by night, it has acquired a repu- 

 tation for unusual activity by day. 

 For this reason it is often called the 

 day mosquito. In the daytime, how- 

 ever, it seeks the darker places in 

 houses and dark-colored clothing. 

 Otherwise its habits and life story are 

 the same as those of the Culex and 

 the Anopheles. 



Their rdle in the spread of disease. 

 The investigations have shown clearly 



that the Anopheles mosquito is the Sole mits the germ causing yellow 



agency in the transmission of malaria fever ' 

 and that ' the Stegomyia plays a similar role in the spread of 

 yellow fever. The common Culex of this country is not proven 

 to be a disease carrier, although it is seriously suspected and is 

 under investigation. But a variety of the Culex called the 

 fatigans, which is widely distributed in the tropical region and 

 especially in the Philippines, transmits the germ of dengue fever. 

 269. Preventive measures. Because of their agency in 

 the transmission of disease germs and their annoying character 

 even when they are not infective, mosquitoes are grouped with 

 the enemies of human welfare, against which a war of extermina- 



