58 Journal New York Entomological Society. [Voi. xxi. 



In the colder and clearer parts of open swamps Culex restuans, 

 occasionally found with C. pipiens as above mentioned, and Uranotce- 

 nia sapphirina is often found ; but Uranotcenia together with Culex 

 perturbans is more often found in permanent swamps. Culex mela- 

 nurus occurs only in those places where the water is very cold and 

 spring-like. Just why these species confine themselves to these en- 

 vironments is not known, but the fact that most of the species are able 

 to maintain themselves well under other conditions would seem to 

 indicate that the preferred environment is not important to the well- 

 being of the species. 



Passing from open fields and swamps to the woodland a totally 

 different set of species are encountered. Most of these breed in the 

 temporary pools formed by spring rains and melting snows, and fre- 

 quently half a dozen or more species may be found in one pool. 

 Approximately in the order of their abundance these species are: 

 Culex canadensis, C. ahfitchii, C. subcantans, C. pretans, C. abserratus, 

 C. miisica, ^des fuscus, C. sylvicola, C. dupreei, C. fitchii, C. palli- 

 dohirta, C. nivitarsis and C. inconspicuus. Three others, Culex auri- 

 fer and C. dyari, so far found only in the woodland in the larger and 

 more permanent bodies of water, and C. saxatilis, which has been 

 found only once in a rock pool may be added. Three more are found 

 normally in the woodland in very restricted situations. These are 

 Culex triseriatus, C. signifer and Anopheles barberi which breed in 

 the water contained in tree hollows. And another species which may 

 be as much attributed to the woodland as to the more open swamps 

 and which is even more closely associated with a particular environ- 

 ment is Wyeomyia smithii, the pitcher plant mosquito which has 

 never been found breeding except in the leaves of the species of 

 Sarracenia and of some orchidaceous plants. 



The question that arises then is : What are the factors that more 

 or less closely limit the distribution of these various species to their 

 environment? We will briefly consider some of the conditions which 

 influence mosquito habits. 



It was at one time believed that all mosquitoes laid eggs in a 

 similar manner — namely, in a boat-shaped mass which floated on the 

 surface of the water. It is now known that eggs are laid in several 

 different ways and that the conditions suitable for oviposition for one 

 species is not suitable for another. Thus of the species around New 



