The Mosquito Must Go 



19 



Man Has Perfected Efficient Methods for Suppressing the 

 Salt-Marsh Mosquito 



Alan is unable to modify the weather, but he can so open 

 the salt marsh 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. 



C D 



Fig. 6. Draining the Salt-Marsh 



A — Half depth plow for shallow ditching 

 B — One-man ditching spade used in spurring 

 C — Full depth — two-man spade 

 D — Filling holes instead of draining 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 

 great percentage of mosquito wrigglers by drying them up. 



In a few limited localities, already referred to, it has been 

 found more practicable to fence the tide out than to cut the 

 large outlets necessary to get rid of the tide water. .But even in 

 such cases, unless the drainage systems are pumped dry, it has 



