Squash Plants Wilt Suddenly May be Squash Vine Borer
Squash plants that suddenly wilt may be infested with squash vine borers.
Check the base of the plant’s stem for damage. You may notice a pile of saw-dust-like material called frass produced by these insects. The adult is a black and orange day flying moth that lays its eggs near the base of the stems. The eggs hatch and the small worm-like larvae borers into, then continues eating inside the stem.
This prevents water and nutrients from moving between the roots and leaves, causing the plant to wilt and eventually die. But don’t give up just yet.
Leave the plants in place while carefully slicing the stem lengthwise. Remove or kill any borers you find. Then cover this portion of the stem with moist soil. This encourages roots to form along the stem so the plant can continue to grow and produce.
A bit more information: Reduce future problems by removing and destroying any borer infested vines this fall. Proper cleanup removes the borers that overwinter in the plant debris. Next spring start watching for this pest early in the season and implement preventative strategies to reduce the risk of this pest.