Pl. 74.
White Ermine Moth.
Caterpillar, chrysalis and cocoon.

Pl. 75.
1, 2, 3.White Ermine Moth.
4, 5.Muslin Moth, females; 6 male.
7.Water Ermine, male; 8 female.

The White Ermine (Spilosoma menthastri).

Older English names for this generally distributed and often common species are The Great Ermine Moth of Wilkes (1773), Harris (1778), and The Large Ermine of Haworth.

On Plate [75] will be found three colour-forms of the moth. Fig. 1 has the typical whitish colour, Fig. 2 is creamy on the fore wings, and Fig. 3 has the fore wings buff. The last represents a specimen from Scotland, where, especially in the western parts of the country, and also in the north of Ireland, and the north-west of England, buff forms, both paler and much darker than the one figured, are not uncommon. Sometimes the Scottish specimens have smoky hind wings. As regards the black spots on the wings, the species is subject to considerable variation. In some examples almost all the markings are entirely absent; in others they are very small and numerous, or large in size and number; the central spots on the fore wings are often united, forming irregular designs. Again, there may be an unusual amount of black spotting on the outer margins, and all other parts of the wings free of spots. All these aberrations in marking, except, perhaps, the central cluster, seem to occur in the various colour forms. An uncommon form, known as var. walkeri, Curtis (Plate [78], Fig. 5), has the black scales gathered together into streaks along the nervures of the fore wings; modifications of this variety have also been found, or reared. Possibly by the careful selection of parent moths showing tendency to the streaked aberration it might happen in a generation or two that var. walkeri would turn up in the breeding cage to reward the rearer for trouble taken in the experiment.

The caterpillar, which is often not uncommon in gardens in August and September, or even later, is brown, with long hairs, and a reddish stripe along the middle of the back. It feeds on

the foliage of low-growing plants, and does not appear to be specially attached to any particular kind. The chrysalis is dark brown, in a close-fitting cocoon of silk and hair from the caterpillar, spun up in odd corners on the ground or at the base of a wall or fence, sometimes between the pales (Plate [74]).