what's eating my basil?

Asked October 11, 2020, 7:57 PM EDT

Hello, this has been going on since I planted it in June. I'm outside a lot, and never see swarms of insects around it, don't see any insects on or around it when I harvest some of it. Do you have any idea what it is, and what I can do to prevent it? Thanks! Nanette

Multnomah County Oregon

1 Response

There are a number of pests that feed on basil. The following are some of the common ones. Aphids, small soft bodied insects, like to feed on tender new growth making it look malformed or puckered. Although they are small you can see aphids on the plant. You may also notice that the plant is sticky from excretions left by the insect. You may be able to wash the insect off with water, or aphids can be controlled by insecticidal soap.
Japanese beetles are about ½ inch long and appear metallic. They chew holes in the leaves. These beetles are easy to see in early morning and in the evening. You can hand pick them and throw them in a bucket of soapy water or spray with a product called Sevin.
Leafhoppers range in length from about 1/8 to ¼ inch and are wedge shaped. Leafhoppers stipple the foliage. The tops of the foliage will appear spotted. Seven can be used to control these insects.
Slugs can chew holes in leaves and will leave behind a slime trail. You can see the slugs on the plant in the evening or very early morning. Hand-pick them and put them in a bucket of soapy water. Products containing iron phosphate will control slugs. Check to be sure they are safe for edibles.
Whiteflies are usually a pest in greenhouses, but could be a problem outdoors. You will find these small white insects on the underside of the leaves. Whiteflies can be controlled with insecticidal soap.
You must determine the pest that is doing the damage before applying controls. If you decide to use a chemical (this includes insecticidal soap) to control the pest, it is very import to carefully read and follow all of the directions on the product label. Make sure the product is labeled for edibles.