In the United States of America, where it is known as the "Cotton Boll worm," "Corn-ear worm," and "Tomato fruit worm," this caterpillar is chiefly destructive to corn crops, as of the five generations stated to occur during the year in the States three occur in cornfields. It also attacks beans, tobacco, pumpkins, melons, oranges, garden flowering-plants, and many kinds of wild plants. The British nurserymen and farmers are perhaps to be congratulated on the fact that this moth is only an accidental visitor and not a native.
The Pale Shoulder (Acontia (Tarache) lucida, var. albicollis).
Only eight specimens of this species seem to have been noted in Britain, and all these are apparently referable to the summer form, var. albicollis, Fabricius. (Plate [19], Fig. 9.) Stephens, who figured it as solaris, Wien Verz. (Haustellata iii., Plate 29, Fig. 3), states that the specimen was in Marsham's collection, but that nothing farther was known about it. He, however, mentions two other specimens "taken within the Metropolitan area about ten years ago [that would be 1820] and four others near Dover above six years ago." Dale fixes the date of Dover captures as June, 1825. On August 25, 1859, a specimen was taken in a clover field at Brighton.
The species has an extensive range abroad, being found in Southern Europe and North-west Africa to Madeira and the Canaries; also in Central Europe, through Western and Central Asia to North India and East Siberia.
The Four-spotted (Acontia (Tarache) luctuosa).
The fore wings of this species (Plate [19], Fig. 10) are sometimes finely powdered with white, but more often the outer marginal area is distinctly flecked with white. The conspicuous central spot is usually white, but occasionally it has a pinkish ochreous tinge; very rarely it is reduced to a narrow streak with a short spur from its outer edge. The white band on the hind wings is sometimes narrowed and contracted below the middle.
The eggs are shown on Plate [23], Fig. 2. They were, when laid on June 17, whity brown marked with reddish brown.
The caterpillar is ochreous greyish inclining to reddish or brownish; three dark-edged stripes along the back, a dark-brown line along the black spiracles, with two finer wavy lines above it; lower down there is a broad stripe of reddish brown; head marked with four lines of black dots. It feeds, at night, during June, July, and August (later in some seasons), on the small bindweed (Convolvulus arvensis), and although it will eat the leaves when nearly full grown it prefers the flowers and seeds in its infancy.
The moth appears in May and June, and a second generation in August and September. In the sunshine it is active on the wing, but in dull weather it hides under herbage, in clover fields, chalky slopes, and rough places where its food plant occurs.