9 



While oiling is cheap and efficient in some cases, it is expen- 

 sive and impractical in large areas like the salt marshes of New 

 Jersey, from which come nearly all of the mosquitoes in that 

 State. 



The control of the house mosquito, the malaria carrying mos- 

 quito, and the other species which breed in stagnant water in 

 the uplands, means detective work, on the part of inspectors, to 

 locate the breeding places. The finding of the breeding place is 

 the difficult part of the upland work; once found, the larvae are 

 easily killed. 



On the tidewater meadows it is just the reverse; the whole 

 area of salt marsh must be drained and kept dry, and this is 

 a work of far greater magnitude than is generally realized. 



in New Jersey, within the five counties of Bergen, Hudson, 

 Essex, Union and Middlesex, that is, from the New York State 

 line on the north down to the vicinity of the Raritan, there are 

 over 35,000 acres of these meadows to be made mosquito-proof, 

 an area equal to 55 square miles, or two and one-half times as 

 large as Manhattan Island. 



For a dozen years past efforts have been made to drain these 

 meadows by systems of ditches, the standard ditch being ten 

 inches wide and thirty inches deep. These ten-inch ditches being 

 connected with wider ones, and so on until they reach the creeks, 

 rivers or bays. Dr. Thomas J. Headlee, the New Jersey State 

 Entomologist, says that it takes an average of 300 lineal feet of 

 ten-inch ditching to the acre for proper drainage which means 

 over 10,600,000 feet for the five counties ; so far about 3,700,000 

 feet have been dug, leaving some 6,900,000 feet yet to be dug to 

 complete this part of the work. 



These ditches have been dug at a cost of from 1% cents to 

 2}< cents per lineal foot, and they must be cleaned every two or 

 three years at a cost of about one-half a cent 1 per foot. 



"The cost of cleaning is too great. None but the ditches with unsatisfac- 

 tory tidal outlets or of great length require yearly cleaning. iWhen not over 

 one-quarter of a mile long, and furnished with strong tidal outlets, they 

 require merely the removal of blockages and do not require reshaping more 

 frequently than once in three years. This year (1916) over one and one-half 

 million linear feet have had the blockages removed for about $600.00. 



