What's eating my acorn squash?

Acorn squash shares the same pest complex as all Cucurbita pepo: squash vine borers are the number-one killer, followed by cucumber beetles and squash bugs. Powdery mildew weakens plants late in the season. Row covers at transplanting and vigilant scouting keep crops productive.

Wilting vine with sawdust-like frass near the stem base; larvae tunnel through the main stalk Cover stems with row fabric until flowering; slit infested vines, remove larvae, re-cover wound with soil; time plantings to avoid adult moth flight

Stippled, wilting leaves that turn crispy brown; grey egg clusters on leaf undersides Scout leaf undersides daily; crush egg masses; apply neem oil or spinosad to nymphs; remove plant debris at season end

Chewed flowers and leaves; bacterial wilt infection causes sudden whole-plant collapse Row covers until first female flowers open; kaolin clay on foliage; pyrethrin as a last resort

White powdery coating on older leaves, reducing photosynthesis and accelerating senescence Improve air circulation; apply diluted neem oil or potassium bicarbonate spray; remove badly affected leaves