458 THE GYPSY MOTH. 



molt, were placed on lettuce leaves which had been treated 

 with arsenate of lead, in the proportion of 1J Ibs. to 150 

 gal. of water. One died the third, one the fourth, two the 

 fifth, three the sixth and two the ninth day ; the remainder 

 lived through the experiment. 



Check experiment : none dead. 



No. 54. June 10, 1894. Ten caterpillars, of the second 

 molt, were placed on lettuce leaves which had been treated 

 with arsenate of lead, in the proportion of 1 Ibs. to 150 

 gal. of water. One died the fifth, two the sixth, one the 

 seventh, two the eighth, three the ninth and one the eleventh 

 day. 



Check experiment : none dead. 



No. 55. June 21, 1894. Ten caterpillars, of the third 

 molt, were placed on elm leaves which had been sprayed with 

 arsenate of lead, in the proportion of 1 Ibs. to 150 gal. of 

 water. Two died the third, two the fifth and one the sixth 

 day ; one died and one pupated the seventh day ; two died 

 the eighth and one the ninth day. 



Check experiment : one died the ninth day. 



No. 56. June 29, 1894. Ten caterpillars, of the fourth 

 molt, were placed on elm leaves which had been sprayed with 

 arsenate of lead, in the proportion of 1 Ibs. to 150 gal. of 

 water. One died the first, one the second, two the third, 

 two the fourth, two the fifth and two the seventh day. 



Check experiment : one pupated the second day ; cine died 

 the fourth and one the sixth day. 



No. 57 (field experiment). June 24, 1893. An apple- 

 tree branch was sprayed with arsenate of lead, in the pro- 

 portion of 1 Ibs. to 150 gal. of water, and nine fourth-molt 

 caterpillars placed upon it. Two died before pupating, and, 

 of the seven that pupated, one died without emerging. 

 Foliage uninjured. 



No. 58. July 9, 1894. Ten caterpillars, of the fifth 

 molt, were placed on elm leaves which had been sprayed with 

 arsenate of lead, in the proportion of 1 Ibs. to 150 gal. 

 of water. One died and one pupated the fourth day ; one 

 died and one pupated the fifth day ; two died the sixth and 

 one the seventh day ; one pupated the ninth day ; two died 

 the eleventh day. 



