[Illustration: Fig. 11.—Larva of the twig girdler. Enlarged.]

[Illustration: Fig. 12.—Adult of the flatheaded apple tree borer.
Enlarged.]

[Illustration: Fig. 13.—Larvae of the flatheaded apple tree borer.]

[Illustration: Fig. 14.—Scars on trunk of pecan tree caused by cutting out flatheaded apple tree borers from their tunnels.]

[Illustration: Fig. 15.—Adult of the buffalo treehopper. Enlarged.]

[Illustration: Fig. 16.—Twig scarred as a result of egg laying by the buffalo treehopper.]

Insects Attacking the Trunk and Branches

A number of insects cause important damage to the trunk and branches of nut trees.

~Obscure scale and others.~ The obscure scale[23] infests a variety of nut trees. On pecan the chief injury results from attacks on branches under three inches in diameter.

[23] ~Chrysomphalus obscurus~ (Comst.).