NO. 8 ANATOMICAL LIFE OF THE MOSQUITO — SNODGRASS 



45 



The abdomen. — The abdomen of the pupa (fig. 16 A) resembles 

 that of the larva except for the lack of the respiratory apparatus, the 

 presence of the tail fins (tf), and the reduction of the tenth segment 

 (X) to a small anus-bearing lobe. The dorsum of the first segment 

 has a special pattern of sclerotization (figs. 16 C, 17 F) and bears the 

 two brushes of spreading hairs that keep the base of the abdomen sus- 

 pended at the surface of the water. It is suggested by Hurst (1890) 

 that these brushes, besides serving as suspensoria, probably also are 



Fig. 17. — Pupal characters and an adult leg of Aedes aegypti. 



A, Left third leg of pupa with adult leg formed inside the cuticle. B, Same 

 leg of adult on emergence, same magnification. C, Right respiratory trumpet, 

 mesal. D, Left mesothoracic wing with adult wing inside the cuticle. E, Left 

 metathoracic wing with halter forming inside it. F, Metanotum and first two ab- 

 dominal segments. G, End of abdomen with tail fins. 



Hit, halter ; Ns, metanotum ; Tra, trachea ; Ws, metathoracic wing ; I, 77, first 

 and second abdominal segments. 



sensory organs responding to vibrations in the water. The pupa be- 

 comes immediately active on any disturbance of the water, even to a 

 tap on the containing vessel. 



The pupal tail fins, as usually drawn in illustration, appear to be 

 attached to the end of the eighth abdominal segment (fig. 17 G). If 

 they are pulled away from the eighth segment, however, they are 

 seen to be carried by a transverse dorsal bar entirely separated from 

 the tergum of the eighth segment (fig. 16 D,E, IXT), which, in fact, 

 is the tergum of the ninth segment. On it is supported also the small 

 tenth segment (X). In the male pupa (E) the ninth segment is a 



