The long caterpillar is variable, but is usually some shade of green above, inclining to whitish beneath, and yellowish between the rings; the lines along the back are paler green, reddish, and olive green. It feeds on low-growing plants, such as knotgrass and dock, and has been reared from the egg in August and September. If eggs were obtained in May it would be possible to raise two generations of moths, or, perhaps, even three, during the year.
The species is an inhabitant of Southern Europe and North Africa, and its range extends to India, Madeira, and the Canaries. In Central Europe, including the British Isles, its occurrence is always a more or less casual event.
Note.—It is possibly incorrect to assign this species to Sterrha, Hübner, which is adopted by some authors for the Acidaliid ochraria. There is, however, considerable doubt among authorities about accepting the Hübnerian genus, but Herrich-Schäffer's genus Sterrha appears to be valid and is here employed. If it has to give way, Pseudosterrha, Warren, or Rhodometra, Meyrick, may have to be used.
Lythria purpuraria has long been reported as a British species, but there does not appear to be any very convincing record of its capture in the British Isles. It is widely distributed in Europe, and generally common. As it is a sun-loving insect, it could hardly escape detection if it occurred in any part of our isles. A note by Mr. V. R. Perkins, in The Zoologist for 1861, p. 7449, should, however, not be overlooked. This refers to the capture, on June 18th, of two male specimens that were disturbed from broom, "not far from the city of Perth, by Mr. D. P. Morrison."
Lead Belle (Ortholitha plumbaria).
Two ordinary examples of this species are shown on Plate [54], Figs. 4, 5. The ground colour is greyish, ranging in one direction to whitish, and in the other to brownish; on the fore wings there are three cross lines, usually reddish-brown in colour, but sometimes dark brown inclining to blackish; the first of these lines is always slender and sometimes very indistinct; the second is often shaded on its outer edge, and the third on its inner edge, with brownish; occasionally the space between the second and third is more or less dusky, especially on the lower half; sometimes these two lines approach each other very closely on the inner margin; the short oblique streak from the tip of the wing to the wavy submarginal line, and also the blackish central dot, are far more distinct in some specimens than in others.
The long stick-like caterpillar is pale ochreous brown, often striped with darker brown or blackish. It feeds on furze (Ulex) and broom (Cytisus), from August to April. The moth is out in May and June, earlier or later according to the season, and is to be found almost everywhere that its food plants flourish.
The Mallow (Ortholitha cervinata).
The fore wings of this species are normally ochreous brown, inclining to reddish, but sometimes the general colour is of a light chocolate tint, and in such specimens the slender white lines edging the dark markings, and the white wavy submarginal line, are more distinct; the central band-like marking occasionally tapers towards the inner margin. (Plate [54], Figs. 6, 7.)