MOSQUITO LARV2E 



The Stegomyia larva hangs more vertically. As a rule, the hairs proceeding 

 from the sides of Culex larvae are straight and the head relatively large. There are 

 also no palmate hairs along the sides. 



The Anophelinae larvae have a small head which is capable of being twisted around 

 with lightning-like rapidity. They are darker in color and have no siphon; float 

 parallel to the surface of the water; have long lateral branching hairs, and on the 

 sides of each of the five or six middle abdominal segments they have a pair of 

 palmate hairs. These palmate hairs are supposed to aid them in keeping their posi- 

 tion on the surface of the water. The larva are usually 

 called "wrigglers." The duration of the larval stage is 

 from one to two weeks, according to the temperature. 



It has been proposed to use larval character- 

 istics in differentiating species but as the larva 

 moults about three times and as the hairs or 

 spines of the exo-skeleton of these different larval 

 stages vary in number and appearance such a 

 scheme has not met with general approval. 



THE PUP.E 



The pupa of the mosquito is an obtected one 

 there being only a closely applied chitinous coating 

 covering it; it does not have a puparium as does 

 the coarctate pupa of the house fly. The mos- 

 quito pupa is lighter than water while the larva 

 is heavier. 



Pupae have a bloated-looking cephalo-thorax and a 

 shrimp-like tail the latter the abdomen. Very impor- 

 tant in examining them with a lens is to note the char- 

 acteristics of the siphon tubes which project from the 

 dorsal surface. These siphons are long and slender in 

 Culex and project from the posterior portion of the head 

 end. In Anophelinae they are broadly funnel-shaped and arise from the middle 

 of the head end. The siphon of the Stegomyia is triangular. 



The bulbous end of the Culex nymph is more vertical than the horizontally placed 

 cephalo-thorax of Anopheles. The duration of pupal life is short only one to three 

 days. At the end of this time the pupa comes to the surface and straightens out. 

 The integument then splits dorsally and the perfect insect emerges. It dries its 

 wings for a time on its raft-like pupal skin and then flies away. 



From the above it will be seen that the stages in the metamorphosis of the mos- 

 quito take about two weeks: one to three days for egg stage; seven to ten days for 

 larval stage, and two to three days for pupal stage. 



FIG. 94. Pupae: i. 

 Culex; 2. Anopheles; 

 3. Aedes calopus. 

 (After Howard.} From 

 P. H. Reports. 



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