726 MOSQUITOES OF NORTH AMERICA 



into the house, nearly all molted on the following day. A day later (May 18) a 

 number of the larv^ pupated. In the meantime there had been severe frosts 

 during the nights and the pools were repeatedly frozen over and thawed out again 

 by the sun of the following day. But in spite of this the larvse developed as 

 rapidly out of doors as in the house, the effect of the sun more than offsetting the 

 retarding influence of the cold nights. The first adults were bred out on May 22. 

 Larvae continued to increase in numbers during the following week, those in the 

 small warm pools being most abundant and developing most rapidly. The small 

 permanent ponds contained no larvae. By the end of the month the larvae of this 

 species had practically all disappeared. 



" Adults of this species first appeared active on May 30 and a few came to bite. 

 They were first noted in numbers on June 5, a warm, sunny day following four 

 days of cold, cloudy weather. They came drifting before the wind, and during 

 calm intervals were very annoying. * * * * This day proved the maximum 

 of activity for this species of mosquito. N"o more swarming of males or matings 

 were observed. On June 10 there was a very high wind, which kept the mos- 

 quitoes close to cover. Only a few came to bite, but these were very bloodthirsty. 

 They would rise out of the grass to leeward and fly against the wind, alighting 

 with a perceptible momentum. 



" June 11 was a hot day, with only light wind. The female mosquitoes 

 appeared less numerous than two days previously. The males were abundant 

 on willow blooms, busily probing for honey.* None were seen swarming. 



" June 12 was warm but windy, yet the males were still found upon the wil- 

 low catkins, although they could maintain their hold only with difficulty. High 

 winds continued for five days and nothing was seen of the mosquitoes. On 

 June 18 the males had nearly all disappeared ; there were none on the willow 

 catkins and only a very few could be found by beating grass and bushes. The 

 females were still in evidence. 



" This species is strictly diurnal and is only active in full daylight. It hides 

 in the grass of the prairie until disturbed or attracted by some passing animal. 

 It appears that the habit of this prairie mosquito, of flying toward prominent 

 objects, under normal conditions brings it to its source of food, some large warm- 

 blooded animal. The blood-sucking habit is doubtless normal in this species, and 

 other foods, such as the honey of flowers, are to be looked upon as supplementary 

 when blood is not available. The idea that but few mosquitoes can obtain a meal 

 of blood is entirely erroneous at least with reference to this species. In 

 former times the prairie teemed with wann-blooded animals, of which the great 

 herds of bison, the antelopes, and deer need only be mentioned. At the present 

 day man, horses, and cattle furnish an abundant supply of blood. On the 

 other hand, in the male this same habit of gathering around prominent objects 

 leads them to the same places to which the females are attracted for food, and 

 thus the union of the sexes is brought about." 



Mr. Knab's observations on the mating habits are quoted in the first volume 

 of this work, on page 130. 



Prairies of Canada and northern United States, from Manitoba westward to 

 British Columbia. 



Winnipeg, Manitoba, June 22, 1907 (F. Knab) ; Aweme, Manitoba, July 3 

 (J. Fletcher), May 17, 190-4, June 10, 1904 (N". Criddle) ; Oxbow, Saskatche- 

 wan, May 30, 1907 (F. Knab) ; Belonge Creek, Saskatchewan, July, 1907 (V. A. 

 Armstrong) ; Kinisteno, Saskatchewan, July 10 (J. Fletcher) ; Regina, Sas- 

 katchewan, June 9, 1907 (T. N". Willing) ; Strassburg, Saskatchewan, June 3, 

 1907 (T. N. Willing) ; Carnduff, Saskatchewan, May 28, 1901 (J. Fletcher) ; 



Knab, Frederick : Mosquitoes as flower visitors. Joiirn. N. Y. Entom. Soc. vol. xv, 1907, 

 p. 215. 



