116 N. J. Mosquito Extermination Association 



FOURTH SESSION, FRIDAY EVENING, FEBRUARY 7 



President Engle: The subject this evening is "The Problem 

 of Finishing the Mosquito Drainage of the New Jersey Salt 

 Marshes/' The first paper is by Dr. Headlee. 



The Problem of Finishing the Mosquito Drainage of the New 

 Jersey Salt Marshes. The Work Involved, its Approximate 

 Cost and Maintenance. 



BY THOMAS J. HEADLEE, PH.D., ENTOMOLOGIST OF THE NEW 

 JERSEY AGRICULTURAL EXPERIMENT STATION. 



The eggs of the salt marsh mosquitoes are in the marsh mud, 

 and every time the meadows are covered with the warm water of 

 summer, either by tide or rain, a brood of wrigglers hatch and 

 soon are on the wing as adult mosquitoes. Two natural agencies 

 limit or entirely eliminate the broods thus started. If the weather 

 is bright, the shallow sheet water covering large areas of marsh 

 surface and filling the shallower pools, is quickly evaporated and 

 the wrigglers die. The deeper pools harbor small killifish, which 

 promptly eat all wrigglers that may appear. The result is that com- 

 paratively few mosquitoes get on the wing. If, however, the weather 

 be cloudy and the atmospheric moisture high, the sheet water dis- 

 appears very slowly and enormous broods may escape. 



If the covering tide is very hig'h — so high as to bury the 

 meadows deeply — killifish penetrate everywhere, and whether the 

 weather be bright or cloudy, prevent the emergence of a large 

 brood of mosquitoes by eating up the wrigglers. 



It is necessary, in order to rid New Jersey of the salt marsh 

 mosquito pest, so to treat the salt marshes that the breeding of 

 mosquitoes on them will be prevented. Man is unable to modify 

 the weather, but he can so open the salt miarsh with ditching that 

 all water upon it will rise and fall with the tide and afford the 

 killifish easy access to all parts of the marsh. Thus he helps the 

 mosquitoes' greatest natural enemy — ^the killifish — to reach and 

 destroy them. 



Furthermore, in view of the fact that the salt marsh surface is 

 normally about one foot above mean high tide, it is clear that this 

 trenching will ordinarily remove all sheet water from the surface 

 and empty all shallow pools, thus destroying the mosquito wrig- 

 glers by drying them up. 



