72 MOTHS AND BUTTERFLIES. 
nocturnal feeder, as it may be found hiding in the daytime among 
the young leaves of the primrose. It is greenish-yellow in color. 
The cotton worm, Aletia agillacea, and the army worm, Hellophila 
unipuncta, both belong to this group of insects, and are well known 
where they occur in numbers on account of their destructiveness. 
The former lives on the leaves of the cotton plant, as its common 
name implies, and is the greatest enemy the cotton-growing industry 
has in the South. This caterpillar is nearly two inches long when 
fully grown, and is green in color with black stripes and black and 
yellow spots. The moth, which is very plain, expands an inch and a 
half, and is brownish-gray, the fore wings being crossed by faint 
wavy lines of a darker color. This insect is found mostly in the 
cotton-growing States, but has been taken in the North, where its 
occurrence is said to be from southern migration. 
The army worm has a wider distribution than the cotton worm, 
being found over the whole of the eastern half of the country as well 
as in Europe and Australia. The moth is plain in color, being 
yellowish-gray and brown with a white dot in the centre of each fore 
wing. These caterpillars feed on grasses, and are sometimes so 
Larva of Hellophila unipuncta, 
abundant as to devour almost every vegetable growth within their 
reach. At such times they commence their march for “ pastures 
new,” and are often seen in great numbers and all marching in one 
direction, which gives them their common name. The caterpillar is 
striped with dark gray or dark brown on a greenish-yellow or gray- 
ish-yellow ground, and is an inch and a half long when fully grown. 
The pupa state is passed in the ground. 
A genus of Noctuide having many American representatives, 
among which are some very beautiful species, is Plusta. The fore 
wings rather pointed, usually of different shades of brown, are fre- 
quently ornamented with a silvery or golden comma-shaped spot Gn 
some species several spots and patches), while the thorax and upper 
part of the abdomen is adorned with tufts of hair-like scales. The 
larvee, generally greenish in color, sometimes striped, are some of 
them injurious to garden vegetables, and spin their thin cocoons, 
through which the pup can be seen, among the leaves. 
