464 THE GYPSY MOTH. 



two the eighth day; one died the fourteenth day; one 

 pupated the twenty-fifth and one the twenty-eighth day. 



No. 87 (field experiment). June 30, 1893. A branch 

 of oak was sprayed with arsenate of lead, in the proportion 

 of 3 Ibs. to 150 gal. of water, and ten caterpillars of the fifth 

 molt placed upon it. All died within three weeks, and six 

 of the ten in less than one week after the branch was sprayed. 

 Foliage uninjured. 



No. 88 (field experiment) . June 30, 1893. A branch 

 of oak was sprayed with arsenate of lead, in the proportion 

 of 3 Ibs. to 150 gal. of water, and ten caterpillars of the fifth 

 molt placed upon it. July 20, the branch was resprayed on 

 account of rain. Only two of these caterpillars pupated and 

 but one emerged. Foliage uninjured. 



4 Ibs. Arsenate of Lead to 150 gal. Water. 



No. 89. March 7, 1894. Ten caterpillars, three days 

 old, were placed on lettuce leaves which had been treated 

 with arsenate of lead, in the proportion of 4 Ibs. to 150 gal. 

 of water. Three died the third, two the fourth and five the 

 fifth day. 



No. 90. May 9, 1895. Ten caterpillars, six days old, 

 were placed on lettuce leaves which had been treated with 

 arsenate of lead, in the proportion of 4 Ibs. to 150 gal. of 

 water. One died the third, two the fourth, five the fifth and 

 two the sixth day. 



Check experiment : none dead. 



No. 91. May 28, 1894. Ten caterpillars, of the first 

 molt, were placed on lettuce leaves which had been treated 

 with arsenate of lead, in the proportion of 4 Ibs. to 150 gal. 

 of water. Two died the third, three the fourth, two the 

 fifth and three the seventh day. 



Check experiment : none dead. 



No. 92. June 10, 1894. Ten caterpillars, of the second 

 molt, were placed on elm leaves which had been sprayed 

 with arsenate of lead, in the proportion of 4 Ibs. to 150 gal. 

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

 fourth, two the fifth, one the sixth, two the seventh and two 

 the eighth day. 



Check experiment : none dead. 



