208 EXPERIMENTAL FARMS 



8-9 EDWARD VII., A. 1909 



considerable injury is done every year to apple and other fruit trees by the Eusty 

 Tussock Moth, not only in eating the leaves of the trees but by gnawing cavities in 

 the sides of the growing apples. Both the Rusty Tussock Moth and the White-marked 

 Tussock Moth occur in Nova Scotia, and the work of both is very similar, but the 

 latter is the more serious pest of the two because it generally occurs in large colonies 

 and not in the scattered way that the former does. The two insects are quite different 

 and easily recognized in all their stages. The caterpillar of the Rusty Tussock Moth 

 is a much less showy insect than its near relative. The general appearance of the 

 body is gray with four short thick tufts of whitish hairs on segments 5, 6, 7 and 8 

 with red spots along the sides and a yellow line beneath the spiracles. The most con- 

 spicuous difference is that the head is black instead of coral red as in the caterpillar 

 of the White-marked Tussock Moth aud there is an extra pair of long tufts of barbed 

 bristles on each side of the 6th segment (counting the head as the 1st), which are 

 entirely lacking in the allied species. The yellow stripes down the back so conspicuous 

 in the White-marked Tussock Moth caterpillar are almost obliterated in that of the 

 Rusty Tussock Moth. The food habits of the Rusty Tussock Moth are very much less 

 restricted than those of the White-marked species, which is almost confined to the 

 foliage of trees, while the caterpillars of the Rusty Tussock Moth may be found upon 

 almost any kind of tree, shrub or herbaceous plant. They seem to be particularly 

 partial to the foliage of geraniums and some other garden flowers. The moths are 

 also different. In the Rusty Tussock Moth the male is of a rust-brown colour, the 

 front wings crosssed by two wavy streaks and there is a conspicuous white crescent 

 near the hind angle of each. The wings expand a little over an inch. The female is 

 gray and practically wingless, in this respect resembling the female of the White- 

 marked Tussock Moth. The male of the White-marked Tussock Moth is gray and 

 the wings are crossed by wavy bands. The base of the front wings bears a dark patch 

 and there is another of smaller size towards the tip. There is also a small whits spot 

 near the outer hind angle of the front wings. In both species the v/ingless females on 

 emerging from their cocoons remain there at rest for their whole moth existence. The 

 males seek tliem out and after pairing, the eggs are laid on or close to the cocoon. 

 Those of the Rusty Tussock Moth are bare and easily distinguishable but in the 

 White-marked Tussock Moth they are covered with a frothy white deposit so that 

 their shape cannot be seen without brealcing up the egg mass. 



Both of these insects are sometimes the cause of considerable injury and neither 

 should be allowed to increase with impunity. In many of our Canadian cities the 

 beautiful shade trees are year after year rendered unsightly by these caterpillars and 

 little is done to check them except an occasional spasmodic effort when they have 

 become so bad that the municipal authorities are compelled to do something. 



The remedies are the spraying of the trees as soon as possible after the young 

 caterpillars have made their appearance, and the collection of the egg-masses during 

 the winter. 



The Hickory Tussock Moth^ Halisidota caryce, TIarr. — Throughout the whole of 

 eastern Canada considerable damage was done to forest trees of several kinds, such as 

 hickory, elm, birch, ash and basswood by the black and white hairy caterpillars of the 

 Hickory Tussock Moth. These caterpillars occurred in unusual abundance in 1907. 

 When young the caterpillars are very gregarious and frequently strip whole branches 

 of a tree. They have a habit of collecting together in dense clusters beneath the leaves 

 at night, but when feeding spreading out all over the tree making silken paths as they 

 travel along the branches. This caterpillar is particularly objectionable as an orchard 

 and shade tree pest because when falling on the bare skin the barbed hairs produce a 

 painful and persistent irritation. 



The caterpillar of the Hickory Tussock Moth when full grown is described as 

 follows by Mr. Arthur Gibson in an article written for the report of the Entomological 

 Society of Ontario for 1907, at page 84. ' The body is clothed with dense tufts of 

 white hairs with a ridge of black hairs down the centre of the back, and two pairs of 



