Pest identification
What's eating my spaghetti squash?
Squash vine borer (Melittia cucurbitae)
Signs: Sudden wilting of main vine; entry hole and sawdust frass at stem base; internal caterpillar destroys vascular tissue.
Control: Protective foil collar at stem base; plant in late June to partially dodge peak moth flight; row cover until flowering; Bt or beneficial nematodes injected into entry holes.
Squash bug (Anasa tristis)
Signs: Egg masses hatch into gray nymphs that feed in crowds; leaves develop yellow patches, wilt, and go crispy; fruit may be deformed.
Control: Scout and crush egg masses every few days; hand-pick adults in the morning when sluggish; lay boards as traps and destroy sheltering bugs.
Cucumber beetles (Acalymma vittatum / Diabrotica undecimpunctata)
Signs: Feeding on blossoms and leaves; vectoring bacterial wilt causes rapid irreversible plant collapse.
Control: Row covers to flowering; yellow sticky traps; pyrethrin or spinosad for heavy populations; remove and bag wilted plants.
Deer and groundhogs
Signs: Fruits gnawed open or whole vines browsed; large distinctive tooth marks on spaghetti squash skin.
Control: Tall deer fence (6–8 ft); live trap or exclusion fencing buried at an L-angle for groundhogs; harvest fruit promptly once mature.
Keep spaghetti squash pest-free
Healthy plants resist pests best. Get the basics right:
- What eats squash — the species this cultivar belongs to
- What eats spaghetti squash — our other guide for the same plant
- What's wrong with my plant? — the diagnosis apps compared
- Common spaghetti squash problems & fixes
- Spaghetti Squash watering schedule
- Spaghetti Squash light requirements
- Full spaghetti squash care guide
Spaghetti Squash pests — FAQ
What is eating my spaghetti squash?
Spaghetti squash faces the classic cucurbit pest lineup. Squash vine borers are the number-one threat in eastern North America, collapsing vines before fruit matures. Squash bugs form destructive colonies on stems and undersides. Cucumber beetles spread bacterial wilt. Deer and groundhogs target the large fruit as it ripens in late summer.
How do I get rid of squash vine borer (melittia cucurbitae) on spaghetti squash?
Sudden wilting of main vine; entry hole and sawdust frass at stem base; internal caterpillar destroys vascular tissue. Protective foil collar at stem base; plant in late June to partially dodge peak moth flight; row cover until flowering; Bt or beneficial nematodes injected into entry holes.
How do I get rid of squash bug (anasa tristis) on spaghetti squash?
Egg masses hatch into gray nymphs that feed in crowds; leaves develop yellow patches, wilt, and go crispy; fruit may be deformed. Scout and crush egg masses every few days; hand-pick adults in the morning when sluggish; lay boards as traps and destroy sheltering bugs.
How do I get rid of cucumber beetles (acalymma vittatum / diabrotica undecimpunctata) on spaghetti squash?
Feeding on blossoms and leaves; vectoring bacterial wilt causes rapid irreversible plant collapse. Row covers to flowering; yellow sticky traps; pyrethrin or spinosad for heavy populations; remove and bag wilted plants.
How do I get rid of deer and groundhogs on spaghetti squash?
Fruits gnawed open or whole vines browsed; large distinctive tooth marks on spaghetti squash skin. Tall deer fence (6–8 ft); live trap or exclusion fencing buried at an L-angle for groundhogs; harvest fruit promptly once mature.