158 



If the captured insects appear to have fully 

 matured ovaries, some of these should be placed 

 in bottles, as previously described (p. 97), and 

 allowed to lay their eggs. 



If care is taken to place only one species in a 

 bottle, the characters of the ovum may be noted, 

 in addition to the adult insect. 



Some of the ova should be placed in fresh 

 water, and an attempt made to determine the 

 characters of the larva (p. 73), when it has hatched 

 out and is sufficiently grown. 



2. Breeding out. — Full-grown larvae, and 

 especially nymphae, are collected. These are 

 collected from every possible source. Scarcely 

 any water will be found free from some form of 

 mosquito larvae. Even strongly brackish waters, 

 containing over one per cent, of salt, often contain 

 large numbers. 



Examine water from the following sources : — 



(i) Domestic utensils, cisterns, tins, pots, 

 calabashes, in which there has been water for 

 three or four days. The larvae of Stegomyia, 

 Culex, etc., and only rarely Anophelines, will be 

 found. 



(ii) Cess pits, pools full of decaying leaves, 

 etc., sewage ditches. Note larvae of certain species 

 of Culex, etc. 



(iii) Observe presence of the larvae of 

 Stegomyia and Culex in the water which collects 

 in the axils of banana leaves and other plants. 

 Also, occasionally, Anophelines in large collections 

 of water of this kind. 



(iv) Puddles of all kinds, with and without 

 algae, ponds, tanks, swamps, rice fields, ditches, 

 canals, rivers, streams, lake margins, and wells, 



