This might be a pest called the common stalk borer (Papaipema nebris). Eggs are laid on grasses and weeds in late summer and fall by a moth; in spring, the eggs hatch and larvae feed on grasses and weeds and other plants, sometimes moving over to rhubarb patches, as well as corn etc. Larvae are very active and move about between plants. They pupate in the soil around July and emerge as moths around August. Clear out any weeds surrounding your patch, and keep borders neat and lawn trimmed nearby to discourage them. To be sure of the pest ID, you might take a sample of the larva and photo of damage to your county’s Cooperative Extension service. For contact information, see http://www.almanac.com/content/cooperative-extension-services
This might be a pest called the common stalk borer (Papaipema nebris). Eggs are laid on grasses and weeds in late summer and fall by a moth; in spring, the eggs hatch and larvae feed on grasses and weeds and other plants, sometimes moving over to rhubarb patches, as well as corn etc. Larvae are very active and move about between plants. They pupate in the soil around July and emerge as moths around August. Clear out any weeds surrounding your patch, and keep borders neat and lawn trimmed nearby to discourage them. To be sure of the pest ID, you might take a sample of the larva and photo of damage to your county’s Cooperative Extension service. For contact information, see http://www.almanac.com/content/cooperative-extension-services