Cucumber Beetles: Identification, Control & Prevention

Cucumber beetles (striped or spotted) attack cucurbits: cucumbers, squash, pumpkins, beans. Found throughout US. Early season: feed on emerging seedlings, often killing them. Larvae feed roots; adults chew leaves, vines, fruit (deep rind scars). They vector bacterial wilt and mosaic virus—diseases often cause more damage than feeding.

Identification

Striped: 1/4", yellow-black abdomen, dark head/antennae. Spotted: same size, 12 black spots on yellow. Larvae: worm-like, white, dark-headed, 3 leg pairs on thorax.

Striped or spotted; blend well with yellow backgrounds.

Damage

Holes, yellowing, wilting leaves. Low yields; stunted, yellow fruit. Diseases overwinter in beetles and debris, reinfecting next spring.

Control

• Scout seedlings early.
• Yellow sticky traps.
• Knock beetles onto cardboard; handheld vacuum; yellow gloves + petroleum jelly for hand-picking.
• Row covers (remove for pollination).
• Few insecticides safe for sensitive cucurbits; apply at emergence. Consult extension.
• Old remedy: nasturtiums and wood ashes.

Keep striped cucumber beetle from wreaking havoc.

Prevention

• Late fall tilling exposes beetles to winter kill.
• Delayed planting—beetles leave when no seedlings found.
• Beneficial predators: braconid wasps, nematodes, soldier beetles.
• Companion planting: tansy repels.
• Bacterial wilt = rapid wilting/death; little cure; prevent next year.

Plants Affected

• Cucumbers
• Squash & Zucchini
• Pumpkins
• Beans