N. J. Mosquito Extermination Association 99 



The Mill Pond and Leeds Lake, Manhasset ; Mill Pond, Ros- 

 lyn; Large Pond, North Shore Country Club Pond, and Mill 

 Pond, Oyster Bay, were lowered every two weeks. More ditches 

 were installed in the Public Swamp, Great Neck, thereby draining 

 a larger area. 



The following table shows the breeding percentage in the 

 upland districts : 



South Shore. North Shore- 



Culex, 18% 43% 



Aedes, 70% 10% 



Anopheles, 12% 47% 



Notwithstanding the high percentage of Anopheles breeding on 

 the North Shore, no cases of malaria were reported from that 

 section of the county. Three cases, without blood tests, were 

 reported — one from Freeport, one from Rockville Centre and 

 one from Garden City. As these cases were not positive, the 

 record established since 19 16 has not been broken. 



WINTER operations. 



The system of installing ditches on the salt marsh, inaugurated 

 last year, was continued. The work began on October 5th; 

 246,566 feet of main ditches and 79,216 feet of spur ditches were 

 installed at a cost of $5,723.48, plus $1,657.66 for measuring, 

 staking and supervision. 



This year three inspectors, instead of two, were employed in 

 each upland district during the winter months. On the South 

 Shore the inspectors cleaned ditches and streams. Most of the 

 cleaning consisted of removing leaves and cat tails, and cutting 

 the thick growth of bushes on the sides of the streams. As a 

 result many \yet areas along the streams dried up. A chain 

 survey of 26 miles of streams was made, and many new viola- 

 tions located and listed for inspection. 



Similar work was done on the North Shore. A culvert was 

 installed to drain a swamp at Port Washington which has always 

 been a heavy breeder. In the future considerable oil will be 

 saved on this violation. 



By employing the inspectors throughout the year much time 

 and labor are saved in the spring. During inclement winter 

 weather the district inspectors worked on maps and charts, and 

 prepared schedules for the ensuing year, while the inspectors en- 

 closed the interior of the garage, and assisted the mechanic in 

 overhauling and painting the cars and boats. 



