S HA DE T REE IN 8S £ CTs 
prevent the beetles from emerging and spreading to healthy 
trees. 
121. The small, bronze green or violet beetles are about one- 
half inch long, with parallel sides, but conspicuously tapering 
wing covers with a blunt tip and a notch where they meet. They 
emerge through peculiar bean-shaped holes in the bark during May 
and June. The eggs are laid during these months in cracks in the 
bark. 
122. The larve on hatching penetrate the bark with zig-zag 
burrows, and work just under the bark, making tortuous burrows 
that frequently intersect, and soon girdle the tree if abundant. 
When the larve are full grown, the burrows are about one-eighth 
inch in diameter. Professor Slingerland has demonstrated that 
from June Ist to October Ist a larva is capable of making a burrow 
over five feet long. 
123. When full grown the larva is about three-quarters of an 
inch long, with the characteristic of the flat-headed borer, but 
with a peculiar brown, horny, forcepslike appendage at the caudal 
end of the body, with two teeth 
upon the inner side of each of the 
two prongs. This pest seems to 
prefer the European white birch, 
but will also attack and kill some of our 
native species, including the black and 
vellow birch. It has been known to 
also attack the paper, or canoe birch. 
125. As stated above, when a tree 
begins to die at the top the only rem- 
edy is to cut and burn the tree before the 
beetles emerge and spread to other trees. 
If all badly infested trees are promptly 
destroyed, the number of beetles that 
emerge can probably be reduced to the 
point where their natural enemies will 
control them. The secrecy of their 
Courtesy Illinois State Entomologist. attack, and the habit of starting upon 
Fis: ii. the upper limbs, puts this pest practi- 
Bvdhoe iiss Bese: cally beyond the reach of the oo 
After S. A. Forbes. insecticides. 
Page 26 
