INSECT PESTS OF OHIO SHADE AND FOREST TREES 325 



utility either as an ornament or for commercial purposes is nearly 

 destroyed. (See Plate LXIX, Figs. 1, 2 and 3.) 



Food plants. The white pine is the preferred host, and is 

 injured more severely than any other, but all of our native pines 

 are subject to attack as are also some of the spruces. 



Distribution. The white pine weevil occupies practically the 

 entire range of the white pine which extends northward from South 

 Carolina to New Brunswick and Canada and westward to include 

 Wisconsin and part of Minnesota. 



Natural enemies. The white pine weevil is preyed upon in the 

 larval and pupal stages by a number of birds which tear open the 

 sides of the cells and destroy the occupant, and the emerged beetles 

 also are picked up. The young of beetles belonging to the family 

 Tenebrionidae are said also to destroy the larvae. 



Bracon pissodis Ashm. and Spathius brachyrus Ashm. have 

 been bred by others from the white pine weevil and the writer has 

 reared two parasites of which the first, Epialtes comstockii Cress, 

 was determined by Mr. R. A. Cushman, and the second, Eurotyma 

 sp., was determined by Mr. A. B. Gahan, of the Bureau of Ento- 

 mology of the United States Department of Agriculture. 



Control. Efforts on the part of entomologists to devise a sim- 

 ple and effective control measure have met with but partial success. 

 Two give some promise. The first consists in collecting the beetles 

 when they collect upon the tip of the central branch in early spring. 

 As described in a previous paragraph, the beetles leave their hiber- 

 nating quarters in early May and collect upon the tip of the leader. 

 When disturbed they have a tendency to drop, hence they may be 

 collected with considerable facility if the branch be bent over the 

 top of a collecting net at least 15 inches in diameter and sharply 

 jarred. A good method of procedure consists in holding the handle 

 of the net in one hand and a lath in the other. By means of the 

 lath the leader is bent over the mouth of the net and lightly tapped. 

 It has been found that if the collecting is repeated at intervals of 

 3 or 4 days for three or four periods, the injury by the insect may 

 be considerably decreased. Moreover, the four collections should 

 be done for something in the neighborhood of $1.50 to $2 per acre. 



The second control method consists in spraying the tip of the 

 central leader with a solution of arsenate of lead, using the material 

 at the rate of 6 pounds of paste or 3 pounds of powder to 50 gallons 

 of water. This application should be made not later than May 1. 



