Leafhopper

The prominent leaf defoliators, as the rose-chafer and flea-beetle, frequently destroy or vastly injure the crop over large districts, and the little leaf-hopper, though rarely preventing a partial crop, is so uniformly present and widely distributed as to probably levy a heavier tribute on the grape in this country than any other insect.

Source: wiktionary

1907, Altus Lacy Quaintance, Cornelius Lott Shear, Insect and Fungous Enemies of the Grape East of the Rocky Mountains, Farmers' Bulletin 284, US Department of Agriculture, page 19, Throughout the United States and Canada, wherever the grape is grown, this small leaf-hopper (Typhlocyba comes Say) will almost invariably be found in greater or less numbers infesting the lower surface of the leaf, where it feeds and breeds, increasing in numbers as the season progresses, until by late summer and fall the vines are often literally swarming with it.

Source: wiktionary

1933, Eubanks Carsner, Curly-top resistance in sugar beets and tests of the resistant variety U. S. No. 1, Technical Bulletin 360, US Department of Agriculture, page 3, Attacks on the leaf hoppers with insecticides and mechanical means have, in the past, been conducted mainly in sugar-beet fields.

Source: wiktionary

One of the chief failings of this species is the susceptibility of the leaves to the attack of the leaf-hopper.

Source: wiktionary