Bombyx, a genus of moths, of which the following are injurious to the gardener.

Bombyx aesculi, the horse-chestnut, or wood leopard moth, the last being the most appropriate name, as descriptive of its spotted form. Its caterpillar injures the wood of the elm, apple, pear, horse-chestnut and walnut.

M. Kollar, in his valuable work on predatory insects, says: - "The caterpillar of this moth is smaller than that of the preceding species, its length being only one inch and a half or two inches. It is hatched in August, moults for the first time in September, and is full grown in June of the following year. From its existence till its transformation it is yellow, with raised shiny black dots, on each of which there is a fine short hair.

"It undergoes its transformation in a strong web under the bark, becoming a brownish-yellow pupa, capable of much extension, dark brown at both extremities, with short wingsheaths, a horn-like point bent forward on the head, and fine hooks on the back of the abdominal segments.

"The moth appears in August towards evening, and is a native of almost all Europe. It is very remarkable from its colour; the ground is white on various parts, on which steel blue dots are scattered. It measures, with extended wings, two inches and a half.

"The female introduces her round orange-coloured eggs, by means of her strong ovipositor, into the trees before named".

Bombyx Bucephala

Buff-tip moth, produces a caterpillar which feeds on the leaves of the lime, beech, birch, alder, oak, willow, and more rarely on those of the rose, apple and pear. M. Kollar says: - "This caterpillar does not appear till the latter end of June or the beginning of July, and feeds to the end of September; when fully grown it measures nearly two inches long, and is about as thick as a goosequill. It is thinly haired, dark brown, with interrupted slender yellow longitudinal stripes, which are intersected by a yellow cross, and between each segment.

"The moth appears in May and June, when it sits with its wings bent downwards, covering the whole body so that it resembles a scroll. When its wings are expanded, it measures from two and a half to three inches wide, the abdomen is pale yellow, spotted with black on the sides. The upper wings are notched, ash-grey, and silver-grey at the base and inner edge, a pale yellow, or silver grey kidney-shaped spot is placed in the middle between two yellow cross lines. The under wings are of a yellowish-white; and have near the inner angle a greyish-brown and often faint double stripe. As the caterpillars when they appear are gregarious, they can easily be destroyed by picking them off when young".

Bombyx Cossus, Goat-Moth

Its caterpillar is most destructive to the wood of fruit trees, though the elm, oak, willow, poplar, and walnut also, are liable to its attacks. M. Kollar says: - "It is one of the largest caterpillars known in Europe, measuring more than four inches in length. It is smooth and shining, beset only here and there with single short hairs. It is dark red on the back, and the spiracles situated at both sides are of the same colour. The sides and lower part of the body are flesh-coloured; the head is black, the first segment also marked with black above.

"After remaining more than two years in the larvae state, and casting its skin eight times, the caterpillar becomes of a light ochre yellow hue, shortly before pupation, which usually takes place in spring; when it makes a strong cocoon of chips of wood and small pieces of bark, which it has gnawed off. The abdomen of the pupa is yellow, and the segments are deeply indented and capable of much extension. The back is furnished with strong pointed spines, sometimes of a reddish-brown colour. The cocoon is situated immediately within the opening in the tree, so that the pupa when arrived at maturity can press itself half out of the hole when the shell bursts, and the moth comes forth usually in the month of June or July, after having reposed in the pupa state for an indefinite time. When at rest the wings are folded together over the back in the form of a roof; it sits quietly in the daytime on the stems of trees, and is difficult to be distinguished on account of its grey colour. It measures with extended wings, from one tip to the other, nearly three inches, and many specimens are more than this; the female is usually larger than the male.

"The female is provided with a strong ovipositor, with which she introduces her eggs in the bark of the tree, the young caterpillars living at first in and between the outer and inner bark, and afterwards, when they are stronger, penetrating into the wood.

"When we have actually ascertained the existence of one of these creatures in a trunk, by the extruded excrement, relief comes too late for the tree, even if we are able to kill the caterpillar, the mischief being already done. Notwithstanding this, the caterpillar should never be left undisturbed, and an attempt should be made to reach it, by enlarging the opening with a garden knife; or endeavouring to kill it by thrusting a piece of pointed wire up the hole of the tree".