66 Journal New York Entomological Society. [Vol. xiv. 



our body plays a significant role in the life of this mosquito. During 

 the hot hours of the day the head and hands of persons resting clothed, 

 in hammock or bed, are besieged by a cloud of perhaps ten or fifteen 

 Stegomyias, mostly males, in incessant serpentine evolutions. Even the 

 males are aggressive during these hours and persecute any uncovered 

 part of the body to suck sweat. If they do not succeed in biting it is 

 not from lack of desire, but owing to the weak mouth-parts. Although 

 it has been frequently asserted that the male Stegomyia bites and sucks 

 blood, neither the author nor any of his colleagues have ever detected 

 one in the act or found one dilated with blood. However, they do 

 alight upon the person, and the author thinks they produce an irritation 

 that only differs in degree from that of the female's bite. While the 

 male does not succeed in perforating the epidermis it certainly irritates 

 it, and a close study of the male mouth-parts would probably show an 

 unusual development for that sex. The disagreeable sensation pro- 

 duced by the males is augmented by their truculent hum, uttered in a 

 thin concert voice. 



The habits of Stegomyia are now discussed in their bearing on the 

 theory of the origin of the blood-sucking habit propounded on a 

 previous page. Clearly sweat belongs to the same order of products 

 as the others sought by Diptera, the blood serum and the moisture on 

 the edge of the eyes. When Stegomyia first associated itself with man 

 both sexes fed upon his perspiration. From this stage the females 

 progressed to the habitual perforation of the epidermis and became 

 professional suckers of human blood. The males continue in the 

 historically more ancient stage of lappers of sweat and similar secre- 

 tions of the human body. 



When Stegomyia is abundant one observes that the males show a 

 certain aloofness and tendency to congregate apart from the females 

 in little clouds of 15 to 20 or more. This manifests itself, for ex- 

 ample, when the males congregate over the edge of a table or cabinet 

 while the females are circulating about the room, or they collect about 

 the upper part of a mosquito-bar while the females are reconnoitring 

 beneath the bed. These elevated positions are points of vantage 

 from which the males pounce upon any female that they detect cross- 

 ing the area of their dominion. 



Stegomyia is a singularly light-loving mosquito. This is shown by 

 the merry hum of the males as well as the females, dancing in ani- 

 mated swarms, when the moderate sunlight of late afternoon shines 



