132 THE OREST TENT CATERPILLAR 



much tramped upon by people or animals, scatter over this- 

 the cocoons as they are collected, not making the layer more 

 than an inch deep; leave the cocoons in this position until 

 the moths begin to emerge ; then rake the cocoons up and, 

 burn them. During the week or ten days that the cocoons- 

 remain here most of the parasites will have left them and 

 found shelter in the turf, where they will complete their devel- 

 opment. By keeping two or three hundred cocoons in a box_ 

 under observation, the time when the first moths come out can. 

 be readily determined. 



