=Ægeria exitiosa=, (_Say_), or _Trochilium exitiosum_, is well known in its larval state as the Peach tree Borer, and is often so destructive as to kill the trees. The habits of the worm as a borer, and its situation at the base of the tree, are somewhat similar to those of the apple tree borer; but while that is the footless grub of a beetle, this is a true caterpillar, the larva of a butterfly or moth, with feet. The females deposit their eggs from June to October, placing them upon the bark at the surface of the ground, sometimes in the forks of the large limbs. The larva enters, and works downward; first consuming the bark, but afterwards eroding the wood also. Gum exudes from the wound, mixed with their castings, and indicates their presence. When ready to enter the pupa form, the worms come to the surface, excavate a hollow in the wood, and prepare a tough leathery follicle or pod, three-fourths of an inch long, in which they repose as pupæ. This, or an analagous insect, attacks the plum tree, and behaves in a similar manner. The double-flowering Almond of our shrubberies is also attacked by the borer. The perfect insect looks more like a wasp than a butterfly, for the wings of all this group are partially clear of feathers, and transparent. It varies in size from a half to three-quarters of an inch in length, and from eight-tenths to one and three-tenths of an inch across. The female varies more than the male, and her wings are larger in proportion to the body, which is heavier. The male is of a deep steel-blue color, with sulphur-yellow marks, and glossy luster. The wings are transparent and glossy; the veins margined and fringed steel-blue. REMEDIES will depend upon the habits of the insect, and must be directed to the pupa and larva, though valuable preventives are applicable to the perfect insect. The worms may be sought out by scraping away the gum and cutting the dead bark until we find them, often along the main roots; the follicles with the pupæ should also be sought. This work can be done in the autumn and spring; if at the former season, the removed earth should be left away from the stem, when coal tar may be applied to destroy any worms left in the tree and to act as a preventive against future attacks, but this substance should be used with great caution. If applied, the earth should be thrown back to the tree. Boiling soap-suds has been used with good effects.