112 • ]\IOSQUITOES OF NORTH AMERICA 



veiy distinctly with the aid of a lens. During the earlier part of the afternoon 

 the females (which by some are supposed to partake of animal juices only) were 

 present in greater numbers than the males, but later on both sexes were about 

 equally represented.' 



"My own observations were made last spring upon Aedes spenceri Theo. 

 during my stay in Saskatchewan. I shall give some particulars of the life his- 

 tory of this species as they throw some light on its feeding habits. This species 

 develops in immense numbers from the numerous ditches and temporary pools 

 of snow-water scattered over the prairie. The females are voracious blood- 

 suckers and in the early part of the summer make life on the prairie a torture 

 for man and beast. The species is strictly diurnal. The season was an unusually 

 late one this year, and the first mosquitoes were seen flying on May 30. The first 

 males were seen swarming on June 5. After several cold, damp days the mos- 

 quitoes were again active on June 9, the females biting, the males swanning. 

 The following day there was a very high wind which confined the mosquitoes to 

 their retreats in the grass. June 11 was a hot day with only light wind. On 

 an excursion into the prairie, early in the afternoon, the female mosquitoes were 

 found much fewer in number, perhaps as a result of the great heat. No males 

 were seen swarming, as had been the case on previous favorable days. However, 

 upon examining the willow bushes along the margins of ponds and ditches the 

 males were found in numbers upon the willow catkins. Often there were five or 

 six on one catkin, confining themselves to that part of it which was in full bloom. 

 They climbed about on the stamens and probed down amongst them to get the 

 honey. They appeared very eager in this work, plunging the proboscis down for 

 a second then quickly withdrawing it to reinsert it in another place, sometimes 

 even scrambling over each other in their eagerness. The palpi, together with an- 

 tennae, are held erect nearly at right angles to the proboscis. There were also a 

 few females at the willow catkins, feeding in the same manner as the males but 

 less eagerly. The folloAving day, June 12, was warm but very windy. Along 

 the river bank the mosquitoes were again found abundant upon the willow 

 blooms, and this in spite of the high wind which must have made it very difficult 

 for them to maintain their position. As before, most of the mosquitoes on the 

 catkins w^ere males. Although there was an abundance of flowers of various 

 kinds on the prairie at this time none of these were visited by the mosquitoes. 

 A period of continuous violent wind followed. When this had subsided the mos- 

 quitoes were again investigated on June 18. The males had now nearly all 

 disappeared ; there were none upon the willow catkins and only a ver}' few could 

 be obtained by beating. 



" Several points are brought out by these data. The life of the male mosquito 

 does not, at the most, extend over more than two weeks. The males do not 

 appear to take food until after the period of swarming or copulation, nor, in 

 spite of the food taken, do they survive long after the mating period. The 

 females probably only resort to flowers when very hungry and blood is not obtain- 

 able. It should be borne in mind that these deductions apply in particular to 

 Aedes spenceri. Now that we are more familiar with the habits of individual 

 species of mosquitoes it is obvious that no statements which apply generally can 

 be made from observations on the habits of one species. Thus, according to Dr. 

 Graenicher's observations, the females of Aedes sylvestris visit flowers in equal 

 numbers with the males. This species, although a well-known blood-sucker, is 

 not so aggressive and persistent in its quest for blood as Aedes spenceri. More- 

 over it is crepuscular in habit and therefore most abundant on the flowers in the 

 evening, while Aedes spenceri frequents them during the day. Aedes sollicitans, 

 both sexes of which have been observed by Smith upon flowers, is noted as a most 

 persistent blood-sucker. In fact in all the species recorded in the foregoing as 



