The Mosquitoes of New Jersey i"]"] 



Lysol. (A commercial product manufactured by Leber and Fink.) 

 The resistance of 2 to 4-mm. C. pipicns larvae to lysol in tap-water 

 in strengths varying from i cc. to 8,000 cc. to i cc. to 50,000 cc. was 

 tested. In i day all were dead in the i to 40,000 solution. 



Phenol. (100 per cent crude carbolic acid furnished by Eimer and 

 Amend.) The resistance of C. pipiens larvae 2 to 4 mm. long to 

 phenol was tested in tap-water at strengths varying from i cc. to 

 1,000 cc. to I cc. to 40,000 cc. In 2 days all were dead in the i to 

 30,000 solution. 



Mixture of 10 cc. pyridine, 10 cc. xylol, and resin to make 25 cc. 

 The resistance of 2 to 4-mm. larvae of C. pipiens to this mixture 

 in tap-water in strengths varying from i cc. to 20,000 cc. to i cc. to 

 50,000 cc. was tested. In i day all were dead in the i to 40,000 so- 

 lution. This experiment was repeated under the same conditions 

 with the same species of larvae, and in 2 days all were dead in the i 

 to 50,000 solution. 



Standard Oil samples. During the winter of 191 5 the writer re- 

 quested the Standard Oil Company to prepare an oil which would 

 give good spreading power with strong staying ability. The com- 

 pany responded with three samples ; no. i and no. 2 were black in 

 color, while no. 3 was a straw yellow. On February 24, 191 5, the 

 writer selected three glass dishes, filled to the same height with 

 distilled water. Each dish had about 70 square inches of water sur- 

 face. Each was treated with 5 cc. of oil. The first received its 

 supply from sample i, the second from sample 2, and the third from 

 sample 3. Thirty-one days later the oil film of no. 3 was complete, 

 while on both no. i and 2 it was broken. Three large glass dishes 

 were then prepared., filled to the same height with water, and each 

 made the recipient of 50 or more 2-mm. larvae of C. pipiens. Oil 

 was introduced at the rate of 3 cc. to the square foot. The first 

 was treated with sample i, the second with no. 2, and the third with 

 no. 3. One day later 8 larvae were alive in no. i, 10 in no. 2 and 

 none in no. 3. 



A test of the lasting power of some of the more promising sub- 

 stances was arranged. Nine wooden wash-tubs were arranged in 

 4 pairs and a check. One series was filled about half-full of red 

 shale soil. 



It is easy to find substances that will kill mosquito larvae very 

 quickly but to get one that will remain effective over a long period 

 seems attended with difficulties. All tubs were filled to the same 

 height with water and were allowed to stand until larvae of C. pipiens 

 appeared in each. 



