STEGOMYIA FASCIATA : EARLY STAGES 217 



in harbours, and finds suitable hiding places in the holds and 

 cabins. It bites during the day-time, especially in the afternoon, and 

 occasionally after dark; Goeldi states that it sometimes bites at 

 night like other mosquitoes. Copulation apparently takes place on 

 the wing, and the males may often be seen accompanying the fe- 

 males ; though they settle on the skin, they do not bite. It is 

 generally believed that under natural conditions the female feeds only 

 on vertebrate blood, but numerous experiments have been carried out 

 to show that both sexes can be kept alive on sweet fluids for long 

 periods. Goeldi, for instance, kept specimens alive for as long as 102 

 days, but no eggs were laid during this time ; there can, therefore, be 

 little doubt that Stegomia fasciata can live under natural conditions 

 for a long time without blood ; it is probable, however, that this food 

 is necessary for the maturation of the eggs. The female can be 

 kept alive for many months, and in nature can probably survive for 

 at least six months. 



Eggs are, as a rule, laid from five to sixteen days after the female 

 takes her first feed of blood; Mitchell states that the female may 

 feed three times before laying the first batch of eggs. There are 

 usually three such batches, but there may be as many as nine ; 

 each egg is laid singly, and the total number laid at a time may vary 

 from twelve to ninety or more. Goeldi thinks that, as a rule, the female 

 lives about fourteen days after laying her last batch of eggs. He found 

 that fertilized eggs may remain dormant for as long as 102 days, 

 and might be laid even after this long period if the female took a feed 

 of blood. 



Stegomyia fasciata is widely distributed, and is found almost in 

 every subtropical and tropical port, and from sea-level to 4000 feet 

 or more above it. 



The eggs, like those of most species of the genus Stegomyia, are black, 

 elongated, and studded with what appear to be small whitish bodies, 



which produce the appearance of a frill ; they hatch 



rt J Early Stages 



out in from three to four days, but may take as long as 



eight days. Theobald long ago discovered the important fact that the 

 eggs were capable of resisting dessication for a considerable time. 

 He was able to hatch out well-formed larvae from eggs which had 

 been sent from Cuba in a dry test tube. In this connection Newstead 

 has carried out more exact experiments. A batch of eggs which had 

 been laid on moist filter paper at Manaos, South America, were first 

 dried in the air, and later in a dessicator for twenty-four hours, and were 

 28 



