3 66 



THE MOSQUITOES 



r trilo- 



which is a small, sharply defined piece, the scutellum; this may be smooth or 

 bed. Underneath and posterior to the scutellum is the metanotum; the metano- 

 tum is bare in Anophelinae and Culicinae, has hairs in Dendromyinae and scales in 

 Joblotinae. 



There is a pair of wings attached to the posterior part of the mesothorax and, 

 more posteriorly still, a pair of rudimentary wings (halteres) attached to the 

 metanotum. 



The wing venation is important. The costa shows as a stout rib 

 or vein bordering the upper side of the wing and running around the. 

 apex and lower border. 



FIG. 91. Anatomy of the mosquito. No. 7 shows various types of scales. 



Below, it has a fringe which may show spots. The location of the spots in the upper 

 part of the costa of anophelines is of great value in differentiating species. Beneath 

 the upper costal border the subcostal vein runs to join the costa at some distance 

 within the apex. The apex is the free end of the wing and the base that attached 

 to the thorax. Running parallel to the subcosta, but reaching the apex, is the ist 

 longitudinal vein. Below that is the 2d longitudinal vein which forks to make 

 the ist fork cell or ist submarginal cell. The 3d longitudinal takes origin at the junc- 

 tion of the supernumerary and midcross veins. The 4th longitudinal divides to 

 form the 2d fork cell (zd posterior cell). The 5th and 6th longitudinal veins 

 arise from the base of the wing and run to the periphery. 



