INSECTICIDES. 



483 



molt, were dipped in electric insecticide and then placed on 

 a fresh leaf. Nine died on the second and one on the third 

 day. The leaf was burned by contact with the caterpillars. 



*'Elphona." 



No. 1. — May 15, 1894. Ten caterpillars, before the 

 first molt, were placed upon a leaf which had been sprayed 

 with Elphona. On the third day all were dead. 



No. 2. — May 15, 1894. Ten caterpillars, before the 

 first molt, were placed on a leaf and sprayed with Elphona. 

 Four died on the third, three on the fourth and three on the 

 fifth day. 



No. 3. — May 15, 1894. Ten caterpillars, before the 

 first molt, were placed in a dish and sprayed with Elphona. 

 Nine died on the first and one on the second day. Foliage 

 badly burned. 



These three insecticides, " Chloro-naptholeum," ''Elec- 

 tric" and " Elphona," were sent to the department by their 

 manufacturers with the claim that they would kill the gypsy 

 moth, but experiments with them proved that when used in 

 proportion sufficiently large to destroy the caterpillars they 

 burned the foliage very seriously. 



*'HYANms Tobacco Mixture" (a Contact Insecticide 

 WITH Tobacco as a Basis). 



No. 1. — May 15, 1894. Ten caterpillars, before the 

 first molt, were placed on a leaf which had been sprayed 

 with Hyannis tobacco mixture. One died on the fourth 

 and one on the sixth day. 



No. 2. — May 15, 1894. Ten caterpillars, before the 

 first molt, were placed on a leaf and both sprayed with 

 Hyannis tobacco mixture. One died on the third, three on 

 the fifth, one on the sixth and two on the seventh day. 



No. 3. — May 15, 1894. Ten caterpillars, before the 

 first molt, were placed in a dish and sprayed with Hyannis 

 tobacco mixture. One died on the third, three on the 

 fourth and two on the sixth day. The strength of the 

 Hyannis tobacco mixture used in this trial was in the pro- 

 portion of 1 part to 100 parts of water. 



