NOTES ON THE NATURAL CONTROL OF OYSTER-SHELL SCALE. 185 



Predators. 



Although, egg parasites play no part in the control of the insect, egg predators 

 play an important one. 



Birds. The eggs of this scale are devoured by birds to a limited extent. Forbush 

 in his " Useful Birds and their Protection " says that " bark lice are . . . on the 

 bill of fare " of cedar warwings. As these birds go south soon after the eggs of the 

 scale are laid, they cannot be of great importance here. Porbush also speaks of 

 Weed rinding in the stomachs of chickadees " remains of what appeared to be the 

 oyster-shell bark-louse." These birds are, of course, welcome members of the 

 Canadian fauna in winter as well as summer. Four years ago in Millville, New 



Fig. 2. Semisareoptes malus, Shimer, ventral 

 view ; in Eastern Canada this mite is the most 

 important factor in controlling the oyster-shell 

 scale. (Original.) 



Brunswick, I had an opportunity of watching a flock of about twenty red-polls making 

 a meal of oyster-shell eggs from a heavily infested apple tree. Afterwards it was 

 found that the snow beneath the tree was darkened by what must have been thousands 

 of scales dropped by the birds, and the tree was found to be covered with little 

 whitish scars where scales had been. It was estimated that about three-fourths of 

 the scales had been taken. In the same district other trees were found with similar 

 scars. As a factor in control, however, even the red-poll is not abundant enough to 

 be of much importance. An interesting note was given me by the late F. M. 

 McKenzie, who wrote " I remember watching under a field-glass a flock of 



