172 STEGOMYIA FASCIATA [CH. 



rarely when at rest, as the two ventral surfaces are brought 

 in apposition. 



The spermatozoa are stored in the spermathecae, but 

 although a fertilized female may thus remain fertile for a 

 long time, eventually the sperm becomes used up and another 

 copulation is necessary before more fertile eggs can be pro- 

 duced. 



The female lays the first batch of eggs a few days after 

 taking its first meal of blood, the exact period varying accord- 

 ing to the conditions of temperature and humidity. When 

 these are very favourable the period may be as short as two 

 days, but at temperatures below 20 C. the interval may be 

 prolonged indefinitely and two or three feeds may elapse before 

 egg-laying commences. The average number of batches of 

 eggs laid is usually two or three, but in individual cases as 

 many as nine batches have been observed. 



The eggs are extruded singly and the number laid on the 

 first occasion is generally 60 to 90. The number of eggs 

 comprising the subsequent batches is always less than that 

 of the first one, this being the most important. Goeldi has 

 found that the females usually die immediately after the final 

 act of parturition, though in two instances individuals survived 

 12 and 14 days respectively. 



The same author also states that fertilized eggs may remain 

 latent in the body of the female for from 23 to 102 days. 

 A meal of blood was capable of causing the female to lay her 

 eggs after these two periods respectively. 



The eggs are generally laid at night, on the surface of 

 almost any stagnant water. They may be found in the water 

 collected in old tins, saucepans, rain-tubs, broken bottles, 

 holes in trees, and practically in every accumulation of water, 

 however slight, occurring in the vicinity of the houses the mos- 

 quito inhabits. The nature of the water seems to be indifferent, 

 for the eggs hatch out in the most stagnant and evil-smelling 

 water, almost as readily as in pure water. 



The egg. The egg consists of an ovoid body, rather more 

 pointed at one end than the other, and is blackish in colour, 

 dotted over with small white hemispherical particles of 



