FOOD PREFERENCES 107 



towards an inquiline of our poultry-houses. And may it not be possible that, 

 furthermore, in the marked intellectual diversity between Culex fatigans and 

 Stegomyia fascmta there is reflected the primitive diversity between their re- 

 spective hosts ? It is certain, and no one will dispute me, that a mosquito must 

 be more expert to persecute man than to persecute poultry, cats or dogs, as the 

 case may be. And are not the rats and house mice, and, among insects, the re- 

 pulsive roaches proof how much effect the daily association with ' homo sapiens ' 

 has upon intellectual development and refinement ? " 



Culex erytJirothorax occurs in Californian swamps exclusively among the tall 

 reeds. Dyar found that " a person sitting on the bank was immune from their 

 attacks, but among the reeds they bit viciously in the daytime." These reeds 

 were inhabited by numerous water-fowl and it is upon these that this species of 

 Culex, without a doubt, normally feeds. Pet caged birds, in regions of mosquito 

 abundance, are reared with difficult}^ and young birds are often killed by mos- 

 quitoes. 



There is reason to believe that many of the species of Aedes prefer mammalian 

 blood. The females of the species breeding upon the salt marshes of our coasts 

 migrate inland in large swarms and these journeys are very probably under- 

 taken in search of mammalian blood. The ferocity of the mosquitoes in northern 

 regions is remarked upon by all who have visited such regions. Linnaus early 

 testified to it from his Lapland experience. Many other authors could be cited. 

 One of us (Knab) experienced it on the prairies of Saskatchewan. 



In the opinion of Knab the blood-sucking instinct is so strong and so pre- 

 cisely adjusted to circumstances that it must be looked upon as a function of the 

 greatest importance to the mosquito. In the case of Aedes spencerii, the most 

 abundant species of the prairies of the northwest, Knab has observed that it has 

 the habit of flying towards prominent objects. Under natural conditions upon 

 the open prairies such prominent objects would always be some warm-blooded 

 animal and this habit demonstrates a very fine adjustment on the part of the 

 mosquito. 



Some writers have held that but few of the mosquitoes which are so numerous 

 in far northern regions could obtain a meal of blood and therefore the blood- 

 sucking habit could not be considered normal or important in the economy of the 

 insect. This idea is based upon an erroneous conception of the fauna of these 

 regions. In fact the northern countries in former times teemed with warm- 

 blooded animals ; it is only necessary to mention the great herds of bison, elk, 

 deer and antelope. Today, where the former inhabitants have disappeared 

 before the settler, they are replaced by horses and cattle, and there is sufficient 

 testimony as to how viciously these are attacked. 



Galli-Yalerio and Eochaz de Jongh, in their investigations upon European 

 mosquitoes, noted that certain mosquitoes showed a preference to animals over 

 man. One of them noted that in a locality in which he had always been bitten 

 by many Aedes nemorosus when there alone, when another person and a white 

 dog were also present these mosquitoes attacked and greatly worried the dog 

 while the persons sitting near were spared. This was the more remarkable as 

 the persons should have been preferred on account of the dark color of their 

 clothing. 



