2/2 ENTOMOLOGICAL NEWS. [June, 'l6 



The Influence of Various Concentrations of Sea 



Water on the Viability of the Salt Marsh 



Mosquitoes Aedes sollicitans and Aedes 



cantator (Dip.). 



By F. E. CHIDESTER, PH.D., and RAYMOND PATTERSON, B.S. 



(From the Entomological Department of the New Jersey Agricul- 

 tural Experiment Station, T. J. Headlee, Entomologist.) 



In the course of an extensive study of the activity of the 

 killifishes of the New Jersey coast, which was undertaken by 

 the senior author at the request of the State Entomologist, it 

 was deemed desirable to obtain records of the salinity, spe- 

 cific gravity and temperature of the water from which each 

 collection was made. In the course of such record taking, it 

 was noted that considerable difference in salinity existed in 

 pools which contained mosquito larvae. 



On April 18, two series of experimental jars were set up 

 in one of the laboratories of the Entomology building. The 

 first series of jars began with 100 cc. of sea water from Rari- 

 tan Bay, with a salinity of 13 per cent, and ran down by steps 

 of 10 cc. dilution with distilled water to pure distilled water 

 in the eleventh jar. The object of this experiment was to de- 

 termine what changes would take change in the larvae of salt 

 marsh mosquitoes taken from pools with a degree of salinity 

 of about 7 per cent, or 8 per cent, and forced to develop in 

 water of a low salinity. The intention was to also subject 

 Culex pipiens to a saline medium and try to change it into a 

 salt water species. 



The second series consisted of boiled down sea water, grad- 

 uated in series by eight steps from 16 per cent, to 35 per cent, 

 salinity. In this experiment the object was to determine what 

 was the lowest toxic strength of salinity for the species used. 

 The two series were supplemented by controls and by two 

 jars of a 50-50 mixture of 13 per cent, sea water and redis- 

 tilled water, placed at different temperatures, one kept low by 

 running water (53 F.), the other placed in a greenhouse 

 where the temperature ran up to 75 F. at times. The jars 

 were covered with cheese cloth after having been supplied 



