16 Circular 111 



eliminate mosquito breeding in a district composed of South 

 Philadelphia and the northeastern part of Delaware Counties. 

 The work is to be continued and breeding permanently elimina- 

 ted by drainage operations now in progress. 



New York considered it a good investment to expend 

 $372,606 in eliminating the breeding of mosquitoes on its 25,450 

 acres of salt marsh. Says Mr. Eugene Winship, Sanitary En- 

 gineer, New York City Department of Health : "The work is com- 

 pleted with a few exceptions and New York is satisfied with the 

 results obtained. Without any doubt the money expended (on 

 salt-marsh mosquito extermination) has been a good investment. 

 In my opinion it is the best investment the city has ever made, 

 not only from a health and comfort, but also from a financial 

 point of view." 



Compared with these expenditures in New York City and 

 Philadelphia, the sum required to complete the eradication of 

 salt-marsh mosquito breeding in the entire State of New Jersey 

 seems small indeed. 



Nature of The Problem, Its Solution and The Cost 



All states have mosquitoes, but only the ones having coastal 

 marshes or lying in reach of them have the salt-marsh species. 

 Those that breed on the immense salt marshes emerge at times 

 in such numbers as to form an atmosphere and to give human 

 beings no peace either day or night. Furthermore, those that 

 breed on the salt-marsh fly and are wind-carried for as far as 40 

 miles over adjacent country. Local efforts to control the mos- 

 quito pest anywhere within a radius of 30 miles of a salt marsh 

 may be annulled by invasions of broods of salt-marsh mosquitoes. 

 Before any effort was made to prevent it, these species covered 

 at times during the summer more than one-half the entire area 

 of the state, and afflicted more than three-fourths of the popu- 

 lation. 



Lest someone should gain a false impression, it should be 

 pointed out that while salt-marsh mosquitoes when aided by fav- 

 orable winds, do unquestionably migrate, a distance of 40 miles, 

 they do not by any means always do so. Only the larger broods 

 cover such distances and then only when aided by favorable 

 winds. High winds, cold winds, and dry winds do not carry 

 mosquitoes, but rather cause them to cling to grass and bushes. 

 Winds that are warm ("about 80 ° F.), that are moist (70 per cent 

 to 90 per cent relative humidity), and that have low velocity (5 

 miles or less per hour) are the ones that favor migration. 



Salt-marsh mosquitoes may breed abundantly only a mile 



