Mail Squash vine borers Squash vine borers are plump looking caterpillars, white in color with a brown head and short legs. They grow to about one inch in length. They tunnel their way into the stem and stalks of squash and cucumbers. The squash vine borer is a key pest of winter squash, gourds and pumpkins in Kentucky. Unfortunately, it is usually noticed only after it has done its damage.
Symptoms appear in mid-summer when a long runner or an entire plant wilts suddenly.
Infested vines usually die beyond the point of attack. Sawdust-like frass near the base of the plant is the best evidence of squash vine borer activity. Careful examination will uncover yellow-brown excrement pushed out through holes in the side of the stem at the point of wilting. If the stem is split open, one to several borers are usually present. The caterpillars reach a length of 1 inch and has a brown head and a cream-colored body.