The young caterpillars feed in companies between leaves which they have spun together, but when nearly full grown they cease to be gregarious. They are also very different in appearance at different ages. When fully fed, the larva is of a reddish-grey colour, spotted with black, with a double row of orange-coloured warts on each side. There is also a little black hump on each of the fifth and twelfth segments. The food plants of this species are sallows (_Salix caprea_ and _S. cinerea_), poplar (_Populus nigra_), and aspen (_P. tremula_). Family--CYMATOPHORIDAE This, the last family of the _Bombyces_, contains seven species of moderate size, the larvae of which are either quite smooth or have small warty prominences. The seven species are grouped into three genera, from two of which we shall select a representative. _The Peach Blossom_ (_Thyatira Batis_) The popular name of this pretty little moth is given on account of the resemblance of the pink patches of its olive-brown fore wings to the petals of the peach flower. It is a moderately common moth, widely distributed in England and Ireland, and flies during June and July. [Illustration: FIG. 136.--THE PEACH BLOSSOM.] The caterpillar is marbled with reddish grey and brown, and has a hump on the third segment, and a smaller prominence on each of the segments six to ten inclusive. It feeds on the bramble (_Rubus fruticosus_) during August and September, and spends the winter in the chrysalis state, inclosed in a loose cocoon among the dead leaves at the root of its food plant. _The Yellow-horned_ (_Asphalia flavicornis_) This is one of the earliest of our moths, appearing on the wing in March, when it may be attracted by means of sugar placed on the bark of the birch (_Betula alba_). [Illustration: FIG. 137.--THE YELLOW-HORNED.] The wings are grey, with a decidedly greenish tinge, crossed by three dark lines near the base, and two others, which are zigzag, just outside the centre. Between these two sets of lines is a conspicuous round pale spot. The hind wings are greyish brown, darker along the hind margin. The larva, which feeds on the above-named tree, is pale greenish, with both white and black dots. It rolls itself up in a leaf, and seldom ventures out of the retreat thus formed. It is fully fed in July or August. CHAPTER XIX _THE NOCTUAE_ We have already noticed that several of our moths fly by day; that some come out of their hiding places at dusk, and settle down again to rest before the deepest shadows of night fall; and that others prefer the darkest hours of the night. The tribe of moths we are next to consider includes the greater number (about three hundred) of our truly nocturnal species, hence the name that heads this chapter.