786 



THE DIPTERA 



eleven days in Myzomyia rossi, while it may be eighteen to twenty- 

 one days in Anopheles maculipennis in the temperate zone. The 

 larva grows by moulting several times. 



Culicine larvae are easily distinguished from Anopheline larvae 

 by the fact that the spiracles are carried on a long respiratory 

 siphon, formed by a prolongation of the dorsum of the eighth 

 abdominal segment, which has been used to distinguish the different 

 species (Fig. 390). 



Below the siphon on the eighth segment there are spines, forming 

 a comb, while along the length of the siphon there is another comb, 

 distal to which is a tuft of hairs. The variations in these structures, 

 together with those in the length and breadth of the siphon, asso- 

 ciated with those of the antennae and clypeus, afford means of classi- 

 fying the Culicine larvae. For further information, consult either 



Theobald's Monograph, vol. iv., 

 p. 6, or Felt's paper, Bulletin 97 

 of the Division of Entomology 

 of the New York State Museum. 

 The Megarhininae, iEdinae, and 

 Uranotaeninae possess larvae be- 

 longing to the Culicine type. 



The pupal stage lasts about 

 forty-eight hours. Towards the 

 end of an afternoon the pupa 

 comes up to the surface, and the 

 dorsal portion of the thorax splits 

 with a T-shaped fissure, and the 

 adult insect or imago emerges. 

 Pupae do not eat. 



Diiferences between the Anc- 

 phelinse and Culicinse. — The differ- 

 ence between these two important 

 families may popularly be de- 

 (After Nuttall and Shipley, Journal scribed as follows: 



of Hygiene^ The Anophelinae, as a rule, 



project from any plane surface on 

 which they may be resting at a sharply defined angle, owing to 

 their head, thorax, and abdomen forming a more or less straight 

 line ; while the Culicinae, 011 the other hand, do not make such a 

 well-defined angle, owing to the fact that the abdomen is not in 

 the same straight line as the long axis of the thorax. The eggs of 

 the Anophelinae are laid singly, while those of the Culicinae are laid 

 in rafts. The larvae of the Anophelinae have no drawn-out siphons, 

 and therefore He more or less parallel to the surface of the water, 

 while the larvae of the Culicinae hang downwards. There are, 

 however, exceptions to these rules — thus, e.g., Myzomyia culicifacies 

 rests on a surface like a Culex, not like an Anopheles. 



Bionomics. — -The imago emerges from the pupa during the late 

 afternoon/ after which the females are ready for fertilization by the 



Fig. 391. — Pupa of Anopheles 

 maculipennis. 



