176 N. J. Agricultural Experiment Station, Bulletin 348 



50 gm. of quassia chips in 50 cc. of distilled water. The resistance 

 of 2 to 4-mm. larvae of C. pipicns to quassia, in tap-water varying 

 from I cc. to 1,000 cc. to 50 cc. to 1,000 cc. was tested. In 2 days al! 

 were dead in the 50 to 1,000 solution. In 3 days no further killing was 

 visible. 



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

 hellebore, in strengths ranging from 6 to 40 gm. to 1,000 cc. of tap- 

 water, was tested. Eight hours before the larvae were introduced 

 the hellebore was placed in the water and thoroughly mixed with it. 

 In 2 days all were dead in the 40 to 1,000 solution. In 3 days a few 

 were dead in the 30 to 1,000 solution. In 8 days all were dead. 



Ginger. The resistance of 2 to 4-mm larvae of C. pipiens to gin- 

 ger, in strengths ranging from 0.5 to 5 gm. per 1,000 cc. of tap-water, 

 was tested. In i day all were dead in the 5 to 1,000 solution, and 

 most of the specimens were dead in the 2 to 1,000 solution. In 2 

 days all were dead. 



Pyroligneous acid. (The purified product made by the Mallin- 

 kodt Chemical Works.) The resistance of 2 to 4-mm. larvae of C. 

 pipiens to pyroligneous acid in tap-water at strengths varying from i 

 cc. to 1,000 cc. to I cc. to 40,000 cc. was tested. At the end of 6 

 days all were alive. 



Carbo-sul. This is a commercial preparation. It is an emulsified 

 carbon disulfide. The resistance of fully-grown larvae and some 

 pupae of A. caiitator and A. soUicitans to carbo-sul was tested in 

 tap-water at strengths varying from 3 cc. to 100 cc. to i cc. to 1,000 

 cc. In one day all larvae in the 3 to 100 solution were killed. The 

 pupae gave up adults which died before they could take wing. The 

 weakest strength killed a few larvae in 36 hours. 



Pyridine. (Technical, from Eimer and Amend.) The resistance 

 of fully-grown larvae and some pupae oi A. cantator, A. soUicitans 

 and C. salinarius to pyridine in tap-water was tested, at strengths 

 varying from o.ooooi cc. to 1,000 cc. to 0.2 cc. to 1,000 cc. In i 

 day all were dead in the 0.2 to 1,000 solution. In 2 days some were 

 dead in the o.i to 1,000 solution. In the latter strength some of the 

 pupae gave up adults which, however, perished before they could take 

 wing. 



Cresol. (U. S. P., from Eimer and Amend.) The resistance of 

 2 to 4-mm. C. pipiens larvae to cresol in tap-water at strengths vary- 

 ing 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 30,000 and stronger solutions. In 2 days 

 all were dead in the i to 50,000 solution. 



