10 



N. J. Mosquito Extermination Association 



TABLE 3 



Salt-Marsh Drainage Work Done by the State Experiment Station and the 

 County Mosquito Extermination Commissions, October 31, 1919 



Experiment Station 

 Ditching 

 Number Number 



County Commission 

 Ditching 

 Number Number 



County 

 Up to and including 1912. 



1913 



1914 



1915 



1916 



1917 



1918 



1919 



of feet 

 cut 



* 1, 036, 1 80 

 689,842 

 321,601 

 713,823 



of feet 

 cleaned 



221,492 

 275,862 

 230,074 



Totals - 3,488,874 



of feet 



cut 

 239,800 

 879,365 

 1,057,167 

 1,971,248 



2,542,713 

 2,176,492 

 912,390 

 1,137,117 



10,916,292 



of feet 

 cleaned 

 470,000 

 1,300,000 

 919,000 



10,099,170 



Total Experiment Station Ditching 3,488,874 feet 



Total County Commission Ditching 10,916,292 feet 



Total Ditching 14,405,166 feet 



♦Maximum figures, probably 25 per cent too high. 



IV. WORK REMAINING TO BE DONE 



The fresh-water mosquito-control problem in New Jersey is of 

 secondary importance compared with the salt-marsh problem. The 

 fresh-water problem, with a few noteworthy exceptions, as in the 

 upper Passaic Valley, is too largely local in character. The fresh- 

 water species, as a rule, do not travel more than a mile or so from 

 their breeding pools. Even the occasional five or six mile migrations 

 of the fresh-water syhestris are scarcely comparable to the thirty- 

 mile migration of the huge broods of mosquitoes periodically thrown 

 of¥ by our coastal marshes. It can be shown, too, that elimination 

 of the breeding of salt-marsh mosquitoes will result directly in a large 

 increase in seashore, agricultural and industrial ratables in the met- 

 ropolitan district of northern New Jersey, in the coastal region and 

 in the farm lands adjacent to these districts. It has been estimated 

 that the suppression of the salt-marsh mosquitoes within five years 

 will, within a period of twenty years, result in an increase of more 

 than 500 million dollars in the taxable values of the state. 



