112 MOSQUITOES OF NORTH AMERICA 
very 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 Aédes 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 swarming. 
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- 
tenne, 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 following 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 were 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 very 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 
Aédes 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 Aédes 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 Aédes spenceri. More- 
over it is crepuscular in habit and therefore most abundant on the flowers in the 
evening, while Aédes spenceri frequents them during the day. Aédes 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 
