210 J. W. SCOTT MACFIE. 



at all, and the first (experiment No. ix) fed only twice in eighteen days. No eggs 

 were laid in either experiment. 



A temperature of 37° C (98*6° F) would therefore appear to have the efiect of 

 shortening the life, diminishing the blood -sucking propensities, and destroying the 

 fertility of Stegomyia fasciata. 



Summary. 



So far as could be determined from laboratory experiments the sequence of events 

 relating to blood feeding and the laying of eggs in the life of Stegomyia fasciata was 

 found to be as follows : — 



On the second or third day after emergence from the pupa the mosquito takes her 

 initial feed of blood. If she has previously been fertilised she lays her first batch of 

 eggs on the sixth or seventh day, and is ready to feed again on blood a few hours later. 

 Thereafter she lays eggs regularly every third or fourth day, and feeds on blood once 

 only after each batch is laid in preparation for the next batch. The female continues 

 to lay batches of eggs throughout her life, and in this way at least fifteen may be 

 deposited. In order that eggs maybe laid at all, both fertihsation and a meal of blood 

 are required, and it is necessary that the fertilisation should precede the blood feed. 

 Once fertilised, the female may continue to lay batches of fertile eggs for at any rate 

 37 days without being reimpregnated. If the eggs are laid in the early morning, she 

 feeds during the day-time ; if in the afternoon or evening, she feeds at night ; but 

 sometimes she refuses an offer to feed in daylight in favour of the next opportunity 

 to feed in the dark. 



