248 NEW YORK STATE MUSEUM 



the restricted sense, rarely attacks men or animals, while Sayomyia 

 and Corethra feed exclusively on vegetation. These latter two are 

 said to inhabit the open country and do not enter human habita- 

 tions. Certain species pass the winter as adults, and all as a rule, 

 fly relatively short distances. Xotable exceptions to this are 

 Culex sollicitans and C. cantator. Very few mosqui- 

 tos are met with in the daytime because they are usually hiding in 

 dark crevices about houses and other shelters, or have taken refuge 

 among foliage or near the base of grasses. These insects are very 

 susceptible to climatic changes, though we believe that the fre- 

 quently noted appearance of large numbers just after rains is due 

 more to the multiplicity of favorable breeding places, than the 

 necessity of moisture for the welfai-e of the adult. Heat favors 

 rapid transformations, and this may hasten the disclosure of 

 unusually large numbers of the pests. 



Migration of flight. The migratory habits of mosquitos have a 

 very important bearing on repressive measures, because if the in- 

 sects are capable of flying long distances it means that consider- 

 able areas must be treated in order to secure immunity from the 

 pests. Extended exi)erience and observation, not only in this but 

 other countries, have shown that the malarial mosquitos. Anophe- 

 les, are very restricted in their habits, flying only 200 to 300 yards, 

 and consequently that local work is exceedingly effective in reduc- 

 ing their numbers. The same is probably true of our house 

 mosquito, Culex pipiens, and to a less extent of a number of 

 other species. This is not the case with the salt marsh mosquito, 

 Culex sollicitans and its associate, C. cantator, both 

 of which, as demonstrated by Dr Smith, are capable of flying or 

 drifting with the wind to a distance of 40 miles or thereabouts. 

 His observations were limited to New Jersey, and we have yet to 

 learn of equally prolonged flights in Xew York State, though data 

 at hand and observations indicate that this species may easily 

 fly or drift several miles. The practical work conducted in the 

 vicinity of Xew York city indicates that a large amount of free- 

 dom, even from these two species, may be secured by work 

 restricted to comparatively limited areas, and as a rule local 



