The moths emerge and fly early in June, and are quite small, measuring, when the wings are expanded, only two-fifths of an inch, Fig. 23, a, enlarged. The fore wings are purplish or slate brown from the base to the middle, the outer half being irregularly marked with dark and light brown.

The Grape Berry Moth Eudemis Botrana S V 803 3 fig23

These insects are two-brooded and the first brood feeds not only on the leaves of the grape, but on tulip, sassafras, vernonia and raspberry. The caterpillars of the second brood emerge when the grapes are nearly grown, and bore in them a winding channel to the pulp, continuing to eat the interior of the berry till the pulp is all consumed, Fig. 23, d, when, if not full grown, they draw one or two other berries close to the first and eat the inside of those.

The mature caterpillar, Fig. 23, b, measures about half an inch in length, is dull greenish, with head and thoracic shield somewhat darker; the internal organs give the body a reddish tinge. It then leaves the grape and forms its cocoon by cutting out a piece of a leaf, leaving it hinged on one side; then rolling the cut end over, fastens it to the leaf, thus making for itself a cocoon in which to pupate. The pupa is dark reddish brown.

The second generation passes the winter in the pupa state, attached to leaves which fall to the ground; therefore, if all the dead and dried leaves be gathered in the fall and burned, also all the decayed fruit, a great many of these insects would be destroyed. As the caterpillars feed inside of the berry, no spraying of the vines with poisons would reach them. The caterpillar makes a discolored spot where it enters the berry, Fig. 23, c. Therefore the infested fruit may be easily detected and destroyed.

There is a small parasite that attacks this insect and helps to keep it in check. The insect has been known in Europe over a hundred years. It is not certain when it was introduced into America, but it is now found from Canada to the Gulf of Mexico, and from the Atlantic to the Pacific Ocean.