_Gortyna nitela_ (Gruen.)
The perfect moth, Fig. 19, 1, expands from one to one and a half
inches. The fore wings are a mouse gray color, tinged with lilac and
sprinkled with fine yellow dots, and distinguished mainly by a white
band extending across the outer part. The moths hibernate in the
perfect state, and in April or May deposit their eggs singly on the
outside of the plant upon which the young are to feed. As soon as the
eggs hatch, which is in about a month, the young larvæ, or
caterpillars, gnaw their way from the outside into the pith.
[Illustration: FIG. 19.]
The plant does not show any sign of decay until the caterpillar is
fully grown, when it dies. The caterpillar, Fig. 19, 2, is about one
and one-fourth inches long, of a reddish brown color, with whitish
stripes along the body. The stripes on the sides are not continuous,
and the shading of the body varies, being darker on the anterior than
on the posterior portion. When fully grown, Fig. 20, the color is
lighter and the stripes are broader. At this stage of life it burrows
into the ground just beneath the surface, and changes into the pupa
state. The pupa is three-fourths of an inch long, and of a mahogany
brown color. The perfect moth appears about the first of September,
and there is only one brood in a season.
[Illustration: FIG. 20.]
The caterpillars feed in the stalks of corn, tomatoes, potatoes,
dahlias, asters, and also in young currant bushes, besides feeding on
many species of weeds. By a close inspection of the plants about the
beginning of July, the spot where the borer entered, which is
generally quite a distance from the ground, may be detected, and the
caterpillar cut out without injury to the plant. This plan is
impracticable for an extensive crop, but by destroying the borers
found in the vines that wilt suddenly, one can lessen the number
another year.