Twig Borers-Bostrichidae

The Bostrichidae, the branch borers and twig borers, are long, cylindrical beetles often bristling with a thick spiny growth. The pronotum is well developed and often completely covers the head like a hood. The last three or four segments of the antennae are fanned to form a flattened claw.

The larvae have very small heads. The enlarged thorax bears well-developed legs.

Sinoxylon sexdenfafum is typical of this family. In the spring these beetles tunnel through tender branches, feeding on wood around leaf buds. The female then digs a deep groove in the tree and lays her eggs in it. When the larvae emerge they burrow still deeper in the wood, sometimes seriously damaging or even killing the tree.

Amphicerus bicaudatus, the apple twig borer, is a common species that can cause considerable damage. The adults feed on the tender branches and twigs of fruit trees.

Scoblus decliva, which occurs in the western United States, is sometimes called the short circuit beetle. It is remarkable in that it sometimes bores through lead cable such as that used in telephone systems. Moisture then enters the cable through the hole left by S. decliva, often resulting in short circuits. This species normally eats wood.