This insect is a native of Europe. It reached this country at Ho-boken, N. J., about 1881, and since that time it has spread eastward, mainly along the coast, and is now found quite abundantly as far east as eastern Massachusetts. It attacks many kinds of shade trees and shrubs, and appears to be most injurious in and near the larger cities and towns.

The adult insect is a good sized moth with white wings bearing numerous blue-black spots. It appears during the latter part of May, from which time specimens may be found till late in September. The eggs are laid in sheltered places such as crevices of the bark, usually on the small branches, and on hatching, the young borers work through the bark to the wood. Here they feed, working downward. When the branch becomes too small for the rapidly growing borer, it leaves it and enters another. Sometimes the boring is along the centre of the branch; sometimes it takes the form of a large cavity, and sometimes it passes around the branch and girdles it. By winter the borer is usually about half grown, and has entered one of the larger branches, leaving weakened smaller ones behind.

The following spring, feeding is resumed in the larger branches, and by the end of this season the borers are full grown. Early the next spring, they work out to the surface and change to quiet pupae, from which the adult moths emerge during the summer.

Spraying for these insects is useless, as the moths do not feed and the borers work inside the branches almost entirely. Infested limbs are quite easily recognized by the woody, partly digested material thrown out of the openings of the tunnels, and these limbs can be cut off and burned, or if not too badly injured a little carbon disulphide (obtained from druggists) can be injected into the openings of the tunnels, which should then be immediately closed with putty or soap, so that the gas produced may not escape, but follow along the tunnel and kill the borer. Badly infested trees are usually too difficult to treat and should be destroyed. Careful watching during the summer, to discover parts attacked before it is too late, followed by the removal or treatment of the infested branches, as described, is the best treatment at present known.