416 THE GYPSY MOTH. 



was dropped upon some egg-clusters, entirely destroying 

 the eggs. 



Pyroligenous Acid. February 10. Eight egg-clusters 

 were moistened with pyroligenous acid, but it would not 

 penetrate the clusters. 



Spruce Gum. Twenty per cent, of spruce gum, thirty- 

 five per cent, of rosin, thirty-five per cent, of cotton-seed 

 oil, five per cent, of turpentine and five per cent, of pine 

 tar were melted and mixed together, and some egg-clusters 

 saturated with the solution. None of the eggs hatched. 



Sulphur Di-oxide. January 25. Five egg-clusters 

 were placed in a tight box and submitted for ten minutes to 

 the fumes of burning sulphur. March 24, about three-fifths 

 of the eggs had hatched. January 25. Five egg-clusters, 

 placed in a tight wooden box, were submitted for twenty 

 minutes to the fumes of burning sulphur. March 24, nearly 

 all of the eggs had hatched. 



Turpentine. A quantity of turpentine was poured on 

 five egg-clusters. It readily penetrated, but apparently did 

 not affect the eggs, as nearly all of them hatched. 



During the month of October, 1893, Mr. C. W. Minott 

 experimented in the field with a number of mixtures having 

 creosote oil as a basis. All of these mixtures were effective 

 in destroying the eggs of the gypsy moth. The lowest per 

 cent, of creosote oil used was in a mixture composed of 

 eighty per cent, of turpentine and twenty per cent, of creo- 

 sote oil. Even when diluted to this degree, it was found to 

 be effective. 



The following experiments on the eggs of the gypsy moth 

 were conducted by Mr. Kirkland, in 1895 : 



Kerosene. January 5. Twelve egg-clusters were treated 

 with kerosene oil ; these hatched April 20. April 25. Five 

 egg-clusters treated with kerosene oil ; hatched May 1 . 



Turpentine. January 5. Ten egg-clusters treated with 

 turpentine; hatched April 18. 



Kerosene and Turpentine. May 2. Egg-clusters which 

 had commenced hatching were soaked in a mixture com- 

 posed of equal parts of kerosene and turpentine. May 6. 



