REPORT OF THE STATE ENTOMOLOGIST I905 



US 



nothing of the satisfaction accruing from the absence of these 

 dangerous and annoying pests. 



Considerable has been written and said about controlling salt 

 marsh mosquitos by a system of dikes designed to prevent the 

 daily ebb and flow of tides within the protected areas. The great 

 trouble with this system is that it is much more expensive than 

 the simple ditching outlined above, and the problem is further 

 complicated by the very slight fall obtainable. Diking supple- 

 mented by considerable filling will undoubtedly prevent breeding 

 over large areas, but the latter is costly and for a term of years 

 at least essential if one would control mosquitos. The Lawrence 

 authorities have experienced more difficulty in preventing breed- 

 ing in a diked and drained marsh where there was no filling than 

 in open marshes, because it was almost impossible to provide for 

 the prompt drainage of small hollows here and there. Further, 

 the slight fall made it impossible to put drain tile low enough, so 

 that it would be beyond the reach of the plow. The result is 

 that drainage systems behind dikes become almost useless in the 

 course of a few years unless there is a large amount of filling. 

 There is no doubt as to the ultimate value of diking and filling, but 

 this work should be charged to land development rather than to 

 mosquito control. 



Draining as outlined above is a comparatively cheap wav of 

 eliminating salt marsh mosquitos, and if it be supplemented by 

 judicious filling, oiling and the introduction of fish into breeding 

 pools which can not be drained, the problem is solved. This work 

 also results in a greatly improved crop of salt marsh hay. The 

 migratory habit of the salt marsh mosquito makes it desirable to 

 extend drainage operations over rather large areas, otherwise com- 

 munities undertaking this warfare may find their efforts partly 

 nullified by swarms coming from more or less distant undrained 

 marshes. We expect shortly that mosquitos originating from adja- 

 cent undrained marshes or other breeding places will be regarded 

 as nuisances which may be abated by prescribed legal measures. 



The control of fresh-water species including malarial mosquitos 

 is ordinarily less difficult than that of the salt marsh forms, because 

 breeding areas are usually very restricted, in many instances limited 

 to cisterns, water barrels or something of the kind. This fact is 

 well recognized at Lawrence, L. I., the authorities insisting that 

 individuals must look after their domestic mosquitos. As a rule 

 it is the small area and not the large one which causes trouble. 

 The presence of a fresh-water form may be regarded as conclu- 



