The range abroad extends to Amurland.
The Ni Moth (Plusia ni).
The present species (Plate [26], Fig. 3) bears a strong resemblance to a small pale specimen of P. gamma; but, as
will be noted, the silvery central Y-mark is differently formed. Here it is made up of a curve somewhat like the letter U, and an oval or round spot, the latter very close to and sometimes, as in the example figured, united with the former.
The caterpillar, which feeds on cabbage and other Cruciferæ, also on lettuce, tomato, etc., is green, inclining to yellowish green and dotted with white; three white lines along the back, and a white stripe along the sides. It is said to be more slender in form than the caterpillar of P. gamma. (Plate [28], Fig. 1.)
The earliest British specimen was taken at flowers of red valerian in a garden at Exeter, August, 1868. The next year a specimen occurred, also in a garden, at Penzance. Then followed captures in Dorset, one 1885, and one (Isle of Portland) 1888. Two caterpillars were found in the Isle of Portland in 1894, and these produced moths in September of that year. At least eight moths were secured at Penzance in 1894, and specimens were subsequently reared from caterpillars found on cabbages in the gardens around Lynwood. In May, 1896, one example of the moth was taken by Mr. Percy Richards at Norbiton, Surrey. The last recorded capture appears to be that by Mr. Finzi of a female specimen at Tenby, South Wales, on June 9, 1906. She deposited a few eggs in the collecting-box, and the caterpillars that hatched from them were reared on broccoli and lettuce, and produced moths, July 24-30.
Plusia ni ranges through south-east and southern Europe, to Asia Minor, North Africa, and the Canaries. In the Isle of Capri it is said to be almost as common as P. gamma. Brassicæ, Riley (1870), is a well-known Plusia in America, where it is classed among noxious insects. It is somewhat larger and browner in colour than European ni, but in every other respect it seems to agree so exactly that it can hardly be considered specifically distinct.
The Silver Y (Plusia gamma).
This species, represented by portraits of two specimens on Plate [26], Figs. 1 and 2, varies somewhat in the ground colour of the fore wings, which ranges from a whitish grey through various tints of grey and brown to velvety black. The melanic form last referred to is very rare, but I caught one example of it at Eastbourne in the late summer of 1888, and I saw, but did not secure, another near Esher in the autumn of 1906; one taken at Dartmoor in September, 1894, is in Mr. F. J. Hanbury's collection.