456 



THE GYPSY MOTH. 



of water. One died the second,' one the seventh, three the 

 ninth, four the tenth and one the eleventh day. 

 Check experiment : none dead. 



^o. 42.— 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 lb. to 150 gal. 

 of water. One died the fifth, two the sixth, three the seventh 

 and four the eighth day. 



Check experiment : one died the seventh and one the 

 eighth day. 



No. 43. — 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 lb. to 150 gal. 

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

 fourth and one the fifth, sixth, seventh, eighth, ninth and 

 tenth days. 



Check experiment : one lost and one dead the seventh day. 



No. 44 (field experiment). — June 26, 1893. An apple- 

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

 portion of 1 lb. to 150 gal. of water, and eigiit fourth-molt 

 caterpillars placed upon it. Of these, only one died before 

 pupating, and, of the seven which pupated, three emerged. 

 Foliage uninjured. 



No. 45 (field experiment). — June 26, 1893. A branch 

 of an apple tree was sprayed with arsenate of lead, in the 

 proportion of 1 lb. to 150 gal. of water, and eight fourth- 

 molt caterpillars placed upon it. Of these, six died before 

 pupating, and, of the two which pupated, one emerged. 

 Foliage uninjured. 



No^ 46.— 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 lb. to 150 gal. 

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

 died the third, one the fourth, two the fifth, one the seventh, 

 tenth, eleventh and sixteenth days. 



Check experiment : one pupated the third day ; one died 

 the seventh, eighth, ninth and eleventh days ; two pupated 

 the twelfth day ; one died the thirteenth and one the four- 

 teenth day ; and one was living at the close of the experi- 

 ment. 



