The Three Humped (Notodonta phœbe = tritophus).
Very little is known in Britain of this Central European moth (Plate [31], Fig. 3). The first specimen of which we have any
knowledge was reared on August 10, 1842 from a caterpillar found in Essex on aspen. This example was included, with two others, one of which was captured in Suffolk, in the collection of the late Dr. Mason, which was dispersed at Stevens' Auction Rooms in March, 1905.
Besides the specimens mentioned above, a caterpillar, which subsequently died, was beaten from alder in the Exeter district in 1870; another was obtained from hazel in Gloucestershire, but this was "ichneumoned." Then there is a record of a moth or caterpillar, presumably the former, occurring in the neighbourhood of Paisley; and there is a report that a caterpillar was once found at the base of an aspen growing on Clapham Common. A specimen was taken at electric light at Bedford, May, 1907.
The caterpillar is green, with three reddish humps on the back, and an interrupted reddish line along the sides. It feeds on poplar in July and August.
The Large Dark Prominent (Notodonta tritophus = torva).
Another Central European species, of which only one specimen is known to have occurred in Britain. This was reared from an egg, or from a caterpillar, obtained in Norfolk in the latter part of the summer of 1882. The moth might be mistaken for a small dark coloured specimen of the next species (N. trepida), but the dark hindwings readily distinguish it (Plate [31], Fig. 4).
The caterpillar, although darker, bears considerable resemblance to that of the Pebble Prominent; it feeds in June and July, and also in September, on aspen.
According to Staudinger this species is the tritophus of Esper, an earlier name than torva, Hübn.; whilst the preceding species, that has so long been referred to tritophus, Fabricius (or trilophus), is found to be phœbe, Siebert, which name has seventeen years' priority.