Watch for Squash Bugs in Vegetable Gardens

Mild temperatures and generous spring moisture have Kansas vegetable gardens off to a great start—but don't let your guard down. Insect pests, especially this time of year, can quickly undo your hard work.

Two frequent culprits are the tomato hornworm and the squash bug. While the hornworm can quickly strip leaves from your tomatoes, squash bugs often do greater harm. These stealthy pests may already be damaging plants before you realize they’ve arrived—then move on just as fast.

Adult squash bugs appear in late May and early June, laying clusters of tiny eggs on the undersides of squash and pumpkin leaves. Once hatched, the nymphs scatter across your plants, feeding aggressively. Their saliva damages plant tissues and disrupts water flow, often leading to wilted vines. They can also transmit cucurbit yellow vine disease, which can kill plants outright. Their feeding on fruit may cause sunken spots or scarring.

To protect your garden, consider a layered approach:

· Prevention: Rotate crops each season, remove plant debris in the fall, and use row covers until flowering to block adult bugs.

· Physical removal: Hand-pick bugs and eggs and drop them in soapy water. Place boards or shingles near plants overnight; bugs hide beneath them, making for easy morning disposal. A strong hose spray can dislodge pests, exposing them for removal.

· Targeted treatments: Dust diatomaceous earth around plants, use insecticidal soap or neem oil directly on bugs, and try companion planting with marigolds, nasturtiums, or radishes to deter them.

· Biological control: Encourage natural predators like spiders, parasitic wasps, and tachinid flies by avoiding broad-spectrum insecticides.

With a little vigilance and a multi-pronged plan, you can outsmart squash bugs and keep your garden growing strong all season long. For more resources contact me at jlcarr@ksu.edu.