It may be mentioned here that a very closely allied, and on the Continent common, species—C. xeranthemi, Boisduval—might easily be mistaken for C. gnaphalii.
The Wormwood (Cucullia absinthii).
This moth is shown on Plate [16], Fig. 4. The fore wings are usually tinged with purplish over the greyish ground colour; black dots on the stigmata give to each of these marks some resemblance to the figure 8.
The caterpillar, which feeds on the flowers and seeds of wormwood (Artemisia absinthium) and will eat mugwort (A. vulgaris), is best found on sunny days. It is yellowish green, suffused with purplish grey on the back of each ring; there are three pale green lines along the back, and an ochreous grey plate on ring 1. To be found in August and early September, but on dull days it must be sought for among the lower leaves, or on the ground. When resting among the flowers it so closely harmonises with them that it might easily escape detection.
The moth is out in July.
The species is perhaps most abundant on the South Devonshire coast, but its range extends into Cornwall, and eastward to the Isle of Portland and the Isle of Wight; it is not uncommon along the coasts of North Devon (Lee and Croyde), Somerset (Minehead), and South Wales. It has also been recorded from North Wales, and from parts of the Suffolk coast. In Ireland, a specimen was taken in a garden at Cromlyn, Westmeath, in 1873, and more recently two specimens of the moth, and also some caterpillars, were obtained at Timoleague, Cork.
Cucullia artemisiæ (abrotani).
This species, of which a Continental example is represented on Plate [16], Fig. 3, is apparently exceedingly rare in this country, and most probably is not a native.
In the collection of the late Dr. Mason, which was dispersed at Stevens' in 1905, there were three specimens, each of which had seemingly been included among series of C. absinthii purchased at three separate sales. A fourth specimen, also mixed with C. absinthii, was in the collection of the late Rev. H. Burney. Two other specimens have been reported from Devonshire, where, it is said, they were found sitting on a fence.