THE BEOWX-TAIL MOTH. 



69 



5. Paris green, 1 pound to 150 gallons of water: — 



6. Scheeles' green, 1 pound to 150 gallons of water : — 



In the fall of 1898, while the newly hatched caterpillars 

 were still feeding, a number of trees at Maiden were 

 sprayed with arsenate of lead at the rate of 12 pounds to 

 150 gallons of water. As the webs were nearl}^ formed at 

 this time, it seemed desirable to keep a certain number of 

 them, to determine whether the poison had killed all of the 

 caterpillars. Later, in April, 1899, the webs were placed 

 in a warm room and isolated, with the following results : — 



243 webs on j)ear : 



April 26, 

 April 27, 

 April 28, 

 April 29, 

 April 30, 



4 webs yielded larvje. 

 25 webs 3-ielded larva?. 



5 webs yielded larvae. 



- webs yielded larvjw. 



- webs yielded Iarva\ 



34, or 14 per cent. 



A number of webs had also been gathered under exactly 

 identical conditions from certain large elm trees that had 

 been sprayed as thoroughly as possible at the same time 

 and with the same strength of poison. These webs' yielded 

 many more larvfe as will be seen by the table below : — 



