Insects

Squash Vine Borers

Squash Vine Borers
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An eastern pest, the squash vine borer is a 1 inch long caterpillar with a white, accordion like body and a brown head. It tunnels inside plant stems, cutting off the flow of nutrients and water. Infested vines may contain just one borer or as many as a hundred.

Target: Primarily squash, but occasionally cucumbers and melons.

Damage: Stems suddenly wilt and die. Greenish, sawdust-like excrement is piled around small entry holes near stem bases and on the ground.

Life cycle: When cucurbits begin to flower, red and black moths lay shiny, mahogany brown eggs singly, usually on stems near plant bases. Caterpillars hatch in 1 to 2 weeks; they bore into stems and feed for about a month, then pupate in the soil. There are one or two generations a year. The pest overwinters underground as either a caterpillar or a pupa.

Notes: By planting early or late, you may manage to avoid peak midsummer damage. Chemical sprays, applied weekly when vines begin to run, kill caterpillars as they bore into stems. If only a few borers are infesting a stem, make lengthwise slits and ply the pests out; then heap soil to just above the highest slit so new roots will form. If stems are badly damaged though, cut them off and destroy them, since borers may be inside. Increase irrigation to affected plants.