REPORT ON MOSQUITOES. 35 



vations made by others to the same effect ; but it would add noth- 

 ing to the force of the statements already made. Further 

 evidence on the point comes under the heading of "Migrations." 



MOSQUITO MIGRATIONS. 



There is no point of greater importance established by this 

 investigation than that certain species of mosquitoes migrate : 

 i. e., they leave the places where they were bom and come to 

 maturity and fly long distances. Prior tO' 1902 the belief was that 

 only in isolated instances, under exceptional conditions, did mos- 

 quitoes fly more than a short distance from the place where they 

 became adult. Their radius of flight was expressed sometimes 

 in feet, more rarely in yards, and almost never in fractions of a 

 mile. Based upon that belief was the conclusion that mosquito 

 control was purely a local matter and that almost any community 

 could rid itself of trouble no matter what the surroundings might 

 be; provided, of course, they were a reasonable distance away. 

 No one fact in mosquito history impressed itself quite so' firmly 

 upon the mind of the public that looked into the matter at all, and 

 the result was, in New Jersey, a series of local efforts in the most 

 progressive communities. These communities did not take kindly 

 to the suggestion when first made, that the bulk of their mos- 

 quito supply was not a local product, and some of them continued 

 their hopeless task until the overwhelming swarms of 1903 and 

 early 1904 seemed to prove all their previous efforts worthless 

 and made them a laughing stock. 



Yet the very earliest systematic collections demonstrated that 

 certain species might be present in overwhelming numbers where 

 no' trace of their larvae could be found. Culex sollicitans was the 

 species that first attracted attention, partly because in my cran- 

 berry investigations in the pine regions it swarmed so numer- 

 ously; partly because it was that year also the dominant species 

 at New Brunswick. I have elsewhere spoken of my efforts to 

 obtain eggs and larvae of this species and my failure to find them 

 inland, while at the shore every pool swarmed with them. My 

 first shore collections were made at Anglesea, where sollicitans 

 was at that time the dominant species. For that reason I did not 

 find cantator and believed sollicitans the sole migrant. In 1902 

 Mr. Brehme took the field, Mr. Dickerson was detailed as oppor- 

 tunity served, and I devoted all available time to the same end. 

 Never were marshes more thoroughly explored, and the result 

 was that instead of one, we found four species breeding on them. 

 Furthermore, we failed absolutely to find any of these larvae 



