What Is Eating My Basil? The 10 Most Common Culprits

basil plant diseases and pests

Have you noticed holes in a basil leaf here or there, or are the leaves of your plant completely eaten away? You probably asked the question, “what is eating my basil?”

Your basil plant is being attacked by pests. Basil has a pleasant smell that tends to attract a wide range of insects and bugs. In this article, we will answer your question of what is eating my basil, identify the 10 most common culprits, and measures to get rid of them.

What Is Eating My Basil: 10 Known Basil Killers

1. Japanese Beetle

A Japanese beetle eating a leaf
Photo by Chris F from Pexels

What is eating my basil, you ask? Probably it’s the Japanese beetles. Japanese beetles are chunky bugs with a metallic green color. They tend to feed on a plant’s leaves from the top downwards. They can eat up all the leaves but leave the leaf veins untouched. They leave the leaves looking lacy.

Usually, they infest in later spring and early summer. Japanese beetles are not picky eaters as they feed on a wide range of plants, so if you have other plants nearby, you may notice that they have been eaten too.

You can get rid of them by picking them off or using beetle traps. You can also place a bowl of soapy water beneath the basil plant and then vigorously shake it to let the beetles drop off.

The most challenging part of controlling a Japanese beetle infestation is getting rid of their larvae from the soil. Use nematodes in the spring season to prevent Japanese beetles. Otherwise, if they have infested the basil plant and soil already, apply Paenibacillus popilliae. It is a bacterium that causes a milky spore disease in the Japanese beetle so they will die off.

2. Slugs

Photo by PhotoMIX Company from Pexels

Slugs like to feed on basil plants. It is crucial to mulch basil plants to retain water, which also creates a moist environment suitable for slugs.

The likelihood of seeing slugs on your growing basil plants during the day is quite low, as they feed at night. However, you may notice a slime trail on the basil leaves. Also, you might find holes on the lower side of the leaves, as slugs hardly feed on the upper parts of leaves.

To ascertain that you have a slug infestation on your basil, inspect the plants at night with a flashlight. Pay attention to the bottom side of the leaves where you are most likely to find them.

If you confirm their presence, you can handpick them. You can also set a beer trap by placing a bowl containing beer under the basil plant. It helps not to water your basil plant in the evening. Instead, water in the morning. Slugs prefer wet environments therefore watering the plant in the evening creates a conducive setting for them to feed at night.

Alternatively, apply diatomaceous earth on the soil beneath the plant. It contains coarse grains that scrape the slug’s skin causing it to dehydrate and die. The scraping effect also discourages the slugs from climbing up the basil plant.

3. Aphids

small aphid on a green leaf in the open air
Source: Shutterstock

If the question “what is eating my basil” lingered inside your head for weeks or months now, then it is likely that Aphids have invaded your basil garden. Aphids are small, soft-bodied insects that feed on a wide range of plants. They can be difficult to spot as you may mistake them for harmless dots on the leaves. If there is an aphid infestation, you will notice the leaves looking deformed or turning yellow and the dots tend to move.

They also excrete honeydew, a sweet shiny substance that attracts ants. Therefore, if you can trace shiny substances and ants on your basil plants there is likely an aphid infestation. Aphids aren’t harmful in small numbers, but in large numbers, they cause significant damage to the basil leaves.

Dishwashing soap, neem oil, and insecticidal soaps are quite effective at battling aphids. Mix 2-3 tablespoons of either with a gallon of water and spray on the basil leaves. The aphids will die within half an hour. Then, rinse off the soap or neem oil and dead aphids with warm water. You may also introduce ladybugs to your herb garden as they eat the aphids.

4. Leafhoppers

Image by Егор Камелев from Pixabay

There is a wide range of leafhoppers that feed on basil leaves and other plants. They are typically wedge-shaped and slender. They are good jumpers, move rapidly when dispersed, and run sideways. Their specific body features vary from one species to another. Their color range include green, brown, and yellow with some colorful markings on the body.

Both adult and nymph leafhoppers feed by puncturing the leaves of a plant to suck out its juices. They have toxic saliva that leaves behind white spots on the leaves and can transmit disease-causing viruses on the plant. It also causes the leaves to curl and yellow.

You can get rid of them by spraying your basil plant with neem oil or other horticultural oils.

5. Caterpillars

Image by 631372 from Pixabay

There are different species of caterpillars in several colors, shapes, and sizes. Typically, caterpillars are the larvae of various moths and butterflies. The most common types of caterpillars on basil plants include cutworms, armyworms, and cabbage loppers.

If there is a caterpillar infestation, you will notice holes on the leaves or chewed edges. The leaves may also appear rolled up and fastened with silk.

To get rid of them, pick them off of the basil leaves and dispose of them in a bucket or bowl with soapy water. Look out for caterpillar eggs and flush them with water. You may also spray the leaves with insecticidal soap, neem oil, and insecticides. It helps to keep away debris on the ground below the plant as it provides a conducive ground for the caterpillars to lay their eggs.

6. Spider Mites

close up of a small spider mite on a dying leaf
Source: Shutterstock

Spider mites look like a crossbreed of spiders and ticks. They are tiny bugs that live on the bottom side of the leaves. They suck the sap out of the leaves causing them to curl. You may also notice small, brown, or yellow spots on the leaves. They also form a spider-like web that provides them with protection as they feed.

Unlike other bugs, they do not respond to insecticides or pesticide, which makes them difficult to control especially if detected later in the season. You should inspect your basil plants for spider mite webs weekly. This way you can catch an infestation early and have a chance at controlling them.

Some gardeners swear by isopropyl alcohol solution for controlling spider mites. Mix the alcohol and water by a 1:4 ratio and spray the leaves, paying special attention to the bottom of the leaves, every week. It is a preventative measure and also controls the early manifestation of spider mites.

7. Whitefly

These are small bugs that fly. Their body is yellowish while the wings are whitish. They cause the basil leaves to yellow, dry up, and fall off. They may also leave a sooty mold on the basil leaves.

There are several methods you can employ to prevent and control whiteflies. Apply a reflective mulch to deter the insects. You can also spray the leaves with insecticidal soap or neem oil spray. Running a stream of water over the basil leaves effectively washes away the whiteflies.

Furthermore, you can vacuum the whiteflies off of basil leaves using a battery-operated vacuum. You could also introduce predatory insects such as lacewings, big-eyed bugs, and a scymnus species to eat up the whiteflies.

8. Leaf Miners

Photo by Christian Krumbholz from Pexels

The term “leaf miners” refers to different species of bugs, including moths, beetles, and flies that eat basil leaves by digging a tunnel inside the leaves. Their infestation is known by observing squiggly lines and patterns on the leaves. They may also cause the leaves to turn yellow or brown.

Leaf miners can be difficult to control as they hide inside the leaves. This protects them from coming into contact with insecticides or predatory insects. The best way to control them is to prevent them in the first place. Neem oil deters them and kills any larvae. If the infestation has already occurred, cut off the affected leaves and burn them to prevent further spread.

9. Bush Crickets

Image by Emphyrio from Pixabay

Also known as katydids. They look like grasshoppers but are smaller. The adults and the nymphs eat the leaves. In some cases, they eat aphids. They are nocturnal and feed at night. They produce a chirping sound, mostly in the summer. Although their infestation is rare, it can be severe when it happens. Apply neem oil on the basil leaves to deter them away.

10. Pets and Amall Animals

Wild birds, chickens, rats, and cats. If you have a cat that loves to nibble on plant leaves, it is best to place the plant out of its reach on windowsills or on tall surfaces. Use netting or wire mesh to fence off your garden. Neem oil, homemade hot pepper, or garlic spray help to keep them away.

Conclusion

Just as you like eating basil, many other animals enjoy its taste and flavor too. If pest infestation is not caught early, it can leave you with no leaves to harvest from your basil plant or cause the plant to die. Therefore, it is important to take the necessary measures to keep these pests from infesting. Keep a close eye on your basil plants to identify any insects and pests and use the measures recommended above to control and get rid of them.

Blogger, Gardener | + posts

I'm Jad, a biologist, blogger, and experienced indoor gardener. I am knowledgeable in plant biology, particularly in plant cultivation and propagation. I founded HerbsWithin.com in 2019 to share my knowledge in indoor gardening with passionate home growers.

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