THE DAVEY INSTITUTE OF TREE SURGERY 
its European cousin. It confines its work more to the trunk and 
the larger limbs, and consequently its burrow can be more easily 
located, and the larve destroyed with a wire or with carbon bi- 
sulphide. 
52. Repellents for preventing egg laying would be a more 
effective means of fighting this insect, inasmuch as only the trunk 
and larger limbs have to be protected instead of the whole tree, as 
with the leopard moth. The moths fly only during the month of 
June and part of July, so the protection would also be required 
for a much shorter time. Where the trees are badly enough in- 
jured to require it, the affected heart-wood should be removed and 
the cavity filled, as explained in a subsequent lesson. 
3. MAPLE SESIAN 
Family SESHD/. Species Sesia acerni Clem. 
53. This moth is much smaller than the preceding species, 
and represents another family of boring lepidopterous larve. It 
isa small, wasp-like moth, with transparent wings and black mark- 
ings. The head and a tuft on the tip of the abdomen are a bright 
red. 
54. The red-headed larve of these moths burrow in the newly 
forming callus around wounds, thus preventing healing. At times 
they cause quite serious injury to both hard and soft maples. 
They have the same habit as other boring Lepidoptera of leaving 
the cast pupa skin in 
the exit hole after the 
moth emerges. 
COLEOPTERA 
55. The greater part 
of the insects that bore 
into the woody tissues 
of plants belong to this 
order. Most of them 
belong to three fam- 
ilies, and are included 
7 i Courtesy Illinois State Entomologist. 
in the three following Fin. 3 
groups: Maple Sesian. After S. A. Forbes. 
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