VI 



MOSQUITOS 



247 



bent down at an angle. The anopheline mosquito on the other hand 

 (top left-hand figure) has its abdomen tilted up at an angle to the solid 

 surface so as to be practically in line with the proboscis, the insect 



HI 



FIG. 107. 



Diagram to illustrate the life-history of Anopheles (A) and Culex (B). (Based on a diagram by 

 Nuttall, in Hindle's Blood-sucking Flies.) 



Note (i) that the adult female Culex has very short maxillary palps whereas in Anopheles of both 

 sexes, as in the male Culex, they are as long as the labium ; 



(2) That in the pupa of both genera the respiratory openings or stigmata are situated at the ends 

 of paired trumpet-shaped projections from the thorax ; and 



(3) That in the larva of Culex the stigmata are situated at the tip of a tubular projection from the 

 eighth segment of the abdomen, and further that the natural position of this larva is hanging downwards 

 from the surface-film of the water, while that of the larva of A nopheles is horizontal immediately 

 beneath the surface-film. 



having consequently the appearance of standing on its head. Other 

 characteristic differences which are of use in distinguishing between 

 anopheline and culicine mosquitos in different phases of their life-history 

 are shown in Fig. 107. 



