The caterpillar is short and stout, and in form very like that of the winter moth; the back and a central dorsal stripe are black, the latter bordered with white, the sides are yellow; the spiracular line is black, broken, and unconnected; the spiracles are black; the head is black, and the edge of the first ring of the body is yellow. (Crewe.) It feeds, in May and June, on purging buckthorn (Rhamnus catharticus), and is to be found between two or more leaves, which it spins together as a hiding place.
In June and July the moth may sometimes be obtained by beating bushes of buckthorn, or the herbage below and around; this plan works best when operated just before dusk. As a British insect it is only found in England, and is most frequent in the southern and eastern counties, but widely distributed in the west to Worcester, and has been found in Lancashire, Westmorland, and Yorks. In the last-named county, caterpillars were obtained freely at Askham Bogs in 1900.
When Stephens wrote of this insect in 1831 he noted its occurrence "in a lane near Fulham." Even so recently as 1906 I obtained specimens on the Putney side of Wimbledon Common.
The range abroad extends to Eastern Siberia.
The Dark Umber (Scotosia rhamnata).
The blackish oblique band on the fore wings of this ochreous brown species (Plate [60], Fig. 7 ♂, 8 ♀) is sometimes indicated only by the blackish lines, the space between them being hardly darker than the general colour. Sometimes all the wings are suffused with blackish brown, and in such specimens the only distinct marking is the whitish submarginal line.
The caterpillar is green, with three lines along the back, the central one dark green, and the others yellow; the hind wings are marked with purple, and a stripe of the same colour runs along under the spiracles. In another form the general colour is greyish with a reddish-brown stripe along the back, and series of spots of the same colour along the sides. It may be found in May and June, concealed between leaves that it has fastened together to form a retreat.
The moth flies in late June and in July, and may be disturbed in the daytime from buckthorn bushes. It is widely distributed, and often common in the South of England, but is rare in the north; and has also been recorded from South Wales.
Note.—This species has been referred to transversata, Hufnagel, and as this is an earlier name it may have to be adopted. According to Prout, both this and the preceding species should be placed in the genus Philereme, Hübner.