MOSQUITOES 



65 



tion once in every sixteen days, or three weeks at the 

 most, to be perfectly safe. 



Adults. — The full-grown male and female Anopheles 

 punctipennis (Fig. 26) are somewhat larger than those 

 of Culex pipiens. The wings appear of a heavier texture 

 and present a spotted appearance, owing to the well- 

 defined spaces, covered with whitish scales. Situated on 

 the front margin of each wing, three-fourths of the length. 

 of the wing from the body, is a yellowish white spot. 

 These two spots together with the other smaller ones 

 give the mosquito a very handsome and distinctive ap- 

 pearance. 



DISTINCTIVE DIFFERENCES BETWEEN THE ADULT FEMALE 

 ANOPHELES AND THE FEMALE MOSQUITOES OF CULEX 



One can readily distinguish with the unaided eye, 

 the malarial mosquitoes from the common mosquitoes 

 provided one can see them 

 close by and at rest. From 

 the head of the female Anoph- 

 eles there project three long, 

 slender bodies of nearly the 

 same length, while from the 

 head of the female Culex 

 there is only one projection. 



Figure 27 gives an idea of Fig. 27. — Head of female Culex, 

 ,i • !•/» i.i i ,i left; female Anopheles, right. 



this dmerence, although the , x 8 ) 

 parts are much enlarged. 



Another difference between the adult Anopheles and 

 Culex is their resting positions. When the common 

 mosquito, Culex, alights on a wall it rests with its body 



