T 99 
The Nympha 
This stage in the tropics usually lasts about forty- 
eight hours. When first the larval coat is cast the 
nymph is light in colour, and may be readily over¬ 
looked. Later, the nymph becomes darker, and 
towards the end and immediately prior to the emer¬ 
gence of the imago, silvery patches due to collections 
of air are seen beneath the cuticle. 
Pupae taken out of the water and kept on moist 
blotting-paper will still develop into winged insects 
(Nuttall and Shipley). 
Egg to Imago .—The developmental cycle for A. maculipennis 
is about thirty days at a temperature of 20°-25° C. In the tropics 
it is much less. Thus the minimum time for Ce. argyrotarsis , M. rossi , 
M. culicifacies is fourteen days. 
Permanent preparations of the nymph are made 
in the same way as those of the larva (p. 191). Place 
two strips of cardboard under the coverglass. 
