American Pomology. Apples

by J. A. Warder

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.

Preventives are sometimes better than cures, and in this case they have been very successfully used. They all consist in means to keep the moth from depositing her eggs in the part of the tree where, alone, the borers can be harmful. Some raise a little mound of earth about the tree in the spring, and allow it to remain there all summer. The first application of this principle consisted in placing a chimney crock about the base of the young tree when planted; into this coal ashes, cinders, or even gravel was placed, which protected the base of the tree. In the autumn the crock was lifted, and the materials scattered. An open box, made of four bits of board, tacked together, answered the same purpose. A cone of coarse brown paper, tied about the tree with grocers' string, or pasted upon the tree itself, when applied, will answer a very good purpose in keeping off the fly.

A small portion of sulphur thrown about the tree is said to have the desired effect, but the statement has not been confirmed by trial. It has been recommended to plant Tansy with every peach tree, but doubt attaches itself to this suggestion also.

In the American Agriculturist, for February, 1865, is a notice of a peach tree protector made of sheet-iron, like a stove-pipe; and in the April number, Mr. Bouthorpe, of Massachusetts, says, he had used a similar apparatus made of zinc, eight inches long, and twice the size of the tree, which was of easy application; the contained space next the tree was to be filled with loose dirt. They were found to be a perfect protection.

Ægeria tipuliformis, (Linn.), or the Currant Borer, has been imported from Europe. The eggs are laid near a bud; when hatched, the worms penetrate the pith of young shoots, killing them.

Ægeria pyri is mentioned by Dr. Harris[43] as having done a good deal of damage to pear trees, by boring under the bark. The perfect insect resembles that of the Currant Borer, and makes its appearance near the end of summer, leaving its chrysalis skin projecting from the hole in the bark, whence it had escaped.

Ægeria polistæformis, or Grape Vine Borer, is mentioned by Mr. Glover in the Patent Office Report for 1854, p. 80. He had received it from North Carolina, where it was very destructive to all vines, except the Scuppernong. This insect has become rather common in the vineyards about Cincinnati, and its depredations, in consequence of the large size of the caterpillar, are very serious. The eggs are laid near the roots of the vine, and the larvæ bore into the bark and wood during the summer, consuming them so completely, that the vine sickens and dies, and often breaks off at the ground, or just below the surface. When fully grown, they measure from an inch to an inch and three-quarters in length, are thick and whitish, and they form a pod-like chrysalis, similar to that of the Peach Tree Borer, but within or beside the injured roots.