Some important larval hairs 



this carries six branched hairs which project forward over the 

 head (see PL IV). Arising from the corner of each eminence, and 

 situated just outside the most external of the six hairs just mentioned, 

 is a characteristic hair that we have called the " Basal hair. " It is 

 seen projecting forwards just outside and parallel to the antenna 

 in Plate VII, fig. .2, A, and in the figures of the larvae of A. 

 karwari, A. culiciformis, &c. It differs in character in different 

 species and is of value in the identification of larvae. The anterior 

 median area of the head is called the clypeus, and it carries on each 

 side a large bunch of hairs called the whorl organs or " feeding 

 brushes. " Lying directly over each whorl organ is a hair which 

 may be called the external frontal hair or external clypeal hair, 

 and between the whorl organs of each side is a pair of hairs close 

 together which may be called the median frontal or clypeal hairs. 

 These four frontal or clypeal hairs project beyond the head and may 

 be simple or branched. They are of great service in the identifi- 

 cation of the larvae of different species and will be more particularly 

 referred to later. In some larvae, e. g., A. turkhudi and A. jeypori- 

 ensis a third hair called the " Posterior hair, " arises from the 

 clypeus just behind and between the two frontal hairs of each side. 

 This hair is also of some service in identification. It is shown in 

 Plate VII, fig. 2, and in Plate VIII, fig. 2. The sides of the mouth 

 are formed by the mandibles, and its floor by the maxillae. Each 

 mandible carries a number of stout teeth, which, working in con- 

 junction with those of the mandible of the opposite side, serve to 

 crush the food. 



In full-grown larvae the thorax is broader than the head or than 

 any of the abdominal segments ( PL IV). It carries a number of 

 branched hairs, and in some species a pair of well-developed palmate 

 hairs similar to those present on the abdominal segments can be 

 easily seen. 



A few words may be added regarding the movements of larva? 

 in water and their method of feeding. " Anopheles " larvae change 

 their position at the surface of the water by a series of very 

 characteristic jerking, darting movements in a backward direction. 

 When actually occupied in feeding they lie stationary beneath the 

 surface film, only their mouth parts moving. " Culex " larvae do 

 not dart along at the surface in a backward direction as " anopheles " 



10] 



