260 MOSQUITOES OF NORTH AMERICA 



which has been widely quoted : '^ A most remarkable peculiarity of this species 

 is that the male stings as well as the female and sucks the blood, producing a 

 puncture equally painful with that produced by the female." It now seems well 

 established that the male does not suck blood. Taylor in referring to this point 

 states that " after a daily experience of over two years, with thousands of Steg- 

 omyia fasciata, we are in a position to state positively that the Havana male of 

 this species does not bite the human skin." However it seeks the exposed por- 

 tions of one's person, apparently to lap the perspiration, and produces a certain 

 amount of irritation. The male also feeds upon sugar and upon various liquids, 

 such as wine, beer or syrup. 



Goeldi has observed an apparent connection between the existence of perspira- 

 tion and the attraction of the yellow-fever mosquito. He says that when one 

 perspires lightly on the neck, the ears, the face, and the hands calopus is at- 

 tracted very greatly. He states that the males are also attracted to any exposed 

 portion of the body covered with perspiration. He thinks that they come to 

 drink the perspiration, and if they do not actually puncture the skin it is simply 

 because they are unable to do so. He is inclined to think that their efforts to 

 perforate the skin produce some irritation. 



The French investigators found that a female will bite 24 hours after emer- 

 gence from the pupa; Peryassii states that both fertilized and virgin females 

 have been induced to suck blood after 18 hours. Under natural conditions it is 

 rare that the female has not been fertilized before this time and it appears that 

 copulation stimulates the desire for blood. Finlay tried to induce females cap- 

 tured fresh from the pupa to bite, but in trials during two and three days he was 

 unsuccessful. The French commission determined that, nevertheless, virgin 

 females will bite. In an experiment with eight virgin females the first one 

 sucked blood after 54 hours. Finlay already noted that the fertilized females 

 are very greedy for blood and this observation has been confirmed by others. 



Finlay observed that after a meal of blood calopus is very sluggish and flies 

 with difficulty ; it seeks a hiding place where it remains quiescent during the 

 process of digestion. During this period the female often, for hours at a time, 

 moves its hind legs in a curious manner and Finlay supposed that during this 

 operation it anointed its body with a secretion from the anus. If the mosquito 

 has sucked enough blood for a full meal it will not return to bite for some time 

 but, on the contrary, will avoid the bare skin, as Finlay thinks, because the 

 warmth is disagreeable to it. He found that from two to four days were con- 

 sumed in the process of digestion and that afterwards the female again became 

 greedy for blood. 



Peryassu records a minimum period of 24 hours for the digestion of a blood 

 meal. Finlay called attention to the important bearing on the transmission 

 of yellow fever of the fact that calopus normally sucks blood repeatedly. Thus 

 a female which he kept alive for 31 days sucked blood 12 times. By biting a 

 number of different individuals the chances of becoming itself infected and of 

 transmitting the disease are greatly increased. Finlay further thought that the 



