422 THE GYPSY MOTH. 



No. 12 (field experiment). June 28, 1893. A branch 

 of hop-hornbeam was sprayed with Paris green, in the pro- 

 portion of Ib. to 150 gal. of water, and ten fifth-molt 

 caterpillars placed upon it. July 5, the foliage was so badly 

 burned that the caterpillars were removed to another branch 

 of hop-hornbeam which was not sprayed. July 11, the 

 foliage having been entirely stripped from the branch, they 

 were again removed to another unsprayed branch. Of these 

 caterpillars, none died before pupating, and four of them 

 completed the process of pupation and emerged. Foliage 

 very badly burned. 



f Ib. Paris Green to 150 gal Water. 



No. 13. April 26, 1894. Ten caterpillars, three days 

 old, were placed on lettuce leaves which had been treated 

 with Paris green, in the proportion of } Ib. to 150 gal. of 

 Avater. Four died the second, five the third and one the 

 fourth day. 



Check experiment : none dead. 



No. 14. May 9,, 1894. Ten caterpillars, six days old, 

 were placed on lettuce leaves which had been treated with 

 Paris green, in the proportion of f Ib. to 150 gal. of water. 

 Three died the second, four the third, two the fifth and one 

 the sixth day. 



Check experiment : none dead. 



No. 15. May 28, 1894. Ten caterpillars, of the first 

 molt, were placed on lettuce leaves which had been treated 

 with Paris green, in the proportion of ^ Ib. to 150 gal. of 

 water. One died the fourth, one the fifth, one the sixth, 

 one the seventh, three the eighth and three the ninth day. 



Check experiment : none dead. 



No. 16. June 10, 1894. Ten caterpillars, of the second 

 molt, were placed on elm leaves which had been sprayed 

 with Paris green, in the proportion of f 11). to 150 gal. of 

 water. One died the fifth, one the seventh, three the ejghth, 

 two the ninth and three the eleventh day. 



Check experiment : none dead. 



No. 17. June 21, 1894. Ten caterpillars, of the third 

 molt, were placed on elm leaves which had been sprayed 



