Insect identification > Coleoptera > True Coleoptera > Grape rootworm

Grape rootworm


The grape rootworm (Fidia viticida Walsh). - The grape rootworm appears to be a native of this country and is found from New York to North Carolina (and Florida?) and west to Dakota, Missouri and Texas.

There is also a California record for it but it appears to be largely replaced there by the California grape rootworm (Bromius obscurus L.). The insect passes the winter as the nearly grown or full-grown larva a number of inches deep in the ground, but in spring it comes nearer the surface and feeds on the roots of the grape until full grown.

Pupation usually occurs two or three inches below the surface and the adult beetles begin to emerge about the time blossoming of the grape ends, most of them appearing during a period of 4 or 5 weeks. The beetles are brown, covered with whitish hairs, are rather stout, about 0.25 in. long, and have long legs.

They feed on the grape leaves, making irregular holes, often so connected as to form narrow crooked slits. The eggs are laid, several hundred in all, placed in clusters of about 30 or 40, mainly under loose strips of bark. These hatch in about 10 days and the tiny grubs drop to the ground and work down to the roots, consuming the smaller ones entirely and burrowing in the larger ones, until winter, when they are full grown or nearly so.

When these insects are abundant, the grape vines may be killed in a year or two but the usual result of their presence is so to check the growth of the plants that little or no crop is obtained. The grape-raising territory of western New York, Pennsylvania and Ohio appears to suffer most from the attacks of this pest.