The grape has many enemies of this kind, but if they are closely watched from the beginning their ravages are easily kept within proper bounds.
The common gray cut-worm will often eat the young tender shoots of the vine, and draw them into the ground below. Wherever this is perceived the rascal can easily be found by digging for him under some of the loose clods of ground below the vine, and should be destroyed without mercy.
Fig. 20.
Delaware.—Berries ½ diameter.
Small worms, belonging to the family of leaf-folders, some of them whitish gray, some bluish green, will in spring make their webs among the young, downy leaves at the end of the shoots, eating the young bunches or buttons, and the leaves. These can be destroyed when summer pruning for the first time. Look close for them, as they are very small; yet very destructive if let alone.
A small, gray beetle, of about the size and color of a hemp-seed, will often eat a hole into the bud, when it is just swelling, and thus destroy it. He is very shy, and will drop from the vine as soon as you come near him. It is a good plan to spread a newspaper under the vine, and then shake it, when he will drop on the paper and can be caught.
Another bug, of about the size of a fly, gray, with round black specks, will sometimes pay us a visit. They will come in swarms, and eat the upper side of the leaves, leaving only the skeletons. They are very destructive, devouring every leaf, as far as they go; they can also be shaken off on a paper or sheet spread under the vine.
The thrip, a small, rather three-cornered, whitish-green insect, has of late been very troublesome, as they eat the under side of the leaves of some varieties, especially the Delaware and Norton's Virginia, when the leaf will show rusty specks on the surface, and finally drop off. It has been recommended to go through the vineyard at night, one man carrying a lighted torch, and the other beating the vines, when they will fly into the flame, and be burnt. They are a great annoyance, and have defoliated whole vineyards here last fall.
Another leaf-folder makes his appearance about mid-summer, making its web on the leaf, drawing it together, and then devouring his own house. It is a small, greenish, and very active worm, who, if he "smells a rat," will drop out of his web, and descend to the ground in double-quick time. I know of no other plan, than to catch him and crush his web between the finger and thumb.
The aphis, or plant louse, often covers the young shoots of the vine, sucking its juices. When a shoot is attacked by them, it will be best to take it off and crush them under your feet, as the shoot is apt to be sickly afterwards, any way.