292 THE MOSQUITOES OF NEW JERSEY 



6 pounds Gardinol W.A. concentrated 

 50 gallons of water 



The Gardinol is first mixed with the water and transferred to the 

 tank. The oil is run into the tank gradually Avith agitator and pump 

 working at full speed. After all the oil is in, the pumping is continued 

 until the entire mixture has passed through the hose and back into the 

 tank two or three times or until the mixture is homogeneous, showing no 

 free oil on the surface. Excessive foaming may be prevented when Gar- 

 dinol is used by dissolving two or three pounds of wool grease (Degras) 

 in the kerosene before adding to the water and Gardinol. The concen- 

 trated stock larvicide should contain a minimum of .07 per cent actual 

 pyrethrins. 



When it is ready to apply, ten parts of water are added to one part 

 of stock emulsion, and it is agitated thoroughly. This diluted larvicide 

 is then sprayed on a water surface the same as oil, a total of fifty to 

 seventy gallons being applied to an acre of water surface. The per 

 spray gallon cost of this material is about one-half the cost of the oil 

 larvicide specified above. If the spray material has to be carried any 

 considerable distance into a swamp or over a marsh, transportation 

 costs of the larvicide are much less, for only the stock solution has to be 

 transported, the necessary water for dilution being taken up at the 

 point of treatment. 



There are many permanent bodies of water, such as fire tanks, bar- 

 rels, tubs, buckets, and vats in which mosquito breeding takes place, so 

 located as to be difficult of access. Here a nonvolatile and long lasting 

 larvicide is called for. Many chemicals qualify for this purpose, but 

 iron sulphate or copper sulphate are most practical. The iron sulphate 

 should be used at the rate of fifty parts to 1,000 parts of water and the 

 copper sulphate at the rate of ten parts to 1,000 parts of water. 



The ideal larvicide, therefore, has been closely approached in killing 

 power, in cheapness, and in freedom from injury to aquatic plants, 

 fish and water fowl, but it still falls far short of desired persistence. 



NEW JERSEY LARVICIDE AS A PROTECTION FOR 

 OUTDOOR EVENING GATHERINGS 



From time to time for many years citizens of New Jersey have in- 

 quired for some method of protecting persons attending outdoor eve- 

 ning gatherings from the mosquito pest. These inquiries have come 

 mostly from individuals contemplating staging outdoor evening parties, 

 but also from associations and in one case from a "drive-in" movie 



