58 N. J. Agricultural Experiment Station, Bulletin 348 



Once each month during the warm season the tides run high. The 

 first brood usually starts during late March or early April and reaches 

 maturity in the last part of April or early May. Another comes out 

 in June, another in July, another in August, and another in Sep- 

 tember. In South Jersey there may be another brood in October 

 and still another small one in November. 



While this regular succession of broods is the usual thing there 

 are many exceptions. Sometimes, as a result of a long continued 

 favoring wind, the tide will remain so high for ten days or two 

 weeks, that the escape of water from drained but shut-in marsh is 

 impossible and a brood of mosquitoes will mature and escape. Some- 

 times the weather will be so rainy and cloudy that the complete 

 removal of the surface water is impossible and a brood may mature and 

 escape. On the other hand, sometimes the tides will pass the full- 

 moon period without rising high enough to cover the marshes and 

 no brood will develop. Sometimes the weather will be so hot and 

 dry that the surface water on the marshes will evaporate before the 

 brood of mosquitoes can mature and none will escape. Sometimes 

 the tides will run so low that areas which are usually swept by high 

 tides with sufficient frequency to prevent breeding, may breed 

 heavily. 



Thus it appears that there are conditions during the mosquito sea- 

 son when almost no marsh will breed and still other conditions when 

 almost any marsh will produce mosquitoes. In every case, however, 

 study will show that to produce mosquitoes warm water free from 

 killifish must He on the marsh surface long enough for maturity to 

 be reached or mosquitoes will not be produced. 



actual work of control 

 Treatment of the open salt marsh 



Briefly stated, the control of the salt-marsh mosquito is a matter 

 of so draining the marsh that none of the water which remains upon 

 it will stagnate but all will rise and fall with the tide and be every- 

 where penetrated by large numbers of salt-marsh minnows com- 

 monly known as killifish. 



Some parts of the salt marsh ordinarily do not breed mosquitoes 

 and the work of eliminating breeding is reduced to the draining of 

 certain parts. The principal factor in determining where on the marsh 

 breeding shall occur when eggs exist under favorable conditions 

 of temperature (55° F. and upward), moisture (enough to cover), 



