How to Get Rid of Lerps on Cup Plant

Cup plant, also known as Silphium perfoliatum, is a native North American perennial that belongs to the sunflower family. It is a popular landscaping plant due to its tall stature, yellow flowers, and ability to attract pollinators. However, cup plants are susceptible to infestations by tiny insects known as lerps. These pests can cause unsightly damage to the plant and reduce its overall health. In this article, we will discuss how to get rid of lerps on cup plants.

What are Lerps?

Lerps are small insects that belong to the family Psyllidae. They are often mistaken for scales or mealybugs due to their similar appearance. Lerps feed on the sap of plants using their piercing-sucking mouthparts. They create a protective covering over themselves made of honeydew and wax, which is commonly called a “lerp”. These coverings not only protect them from predators but also make it difficult for pesticides to reach them.

Signs of Lerp Infestation

The first sign of lerp infestation is the appearance of small white or brown bumps on the leaves and stems of the plant. These bumps are actually the lerps’ protective coverings. As the infestation progresses, the plant may exhibit stunted growth, yellowing leaves, and wilting.

How to Get Rid of Lerps on Cup Plant

1. Prune Infested Branches

The first step in getting rid of lerps on cup plants is to prune any infested branches or leaves. This will help to remove a significant portion of the lerps from the plant and prevent them from spreading to other parts.

2. Use Insecticidal Soap

Insecticidal soap is an effective method for controlling lerps on cup plants. It works by suffocating the insects and breaking down their protective covering. To use insecticidal soap, mix one tablespoon of soap per gallon of water and spray it directly onto the affected areas of the plant. Repeat the process every seven to ten days until the infestation is under control.

3. Apply Neem Oil

Neem oil is another natural insecticide that can be used to control lerps on cup plants. It works by disrupting the insect’s hormonal balance and preventing them from feeding and reproducing. To use neem oil, mix two tablespoons of oil with one gallon of water and spray it onto the affected areas of the plant. Repeat the process every seven to ten days until the infestation is under control.

4. Introduce Natural Predators

Introducing natural predators such as ladybugs or lacewings can be an effective method for controlling lerp infestations. These insects feed on lerps and can help to reduce their population. You can purchase these predators from a garden supply store or order them online.

FAQ

Are lerps harmful to humans?

No, lerps are not harmful to humans. They only feed on plants and do not bite or sting.

Can I use chemical pesticides to control lerp infestations?

Yes, chemical pesticides can be used to control lerp infestations, but they should be used as a last resort. Chemical pesticides can harm beneficial insects and pollinators, and they can also contribute to pesticide resistance.

How can I prevent lerp infestations?

To prevent lerp infestations, make sure to keep your cup plants healthy by providing them with adequate water and nutrients. Prune any dead or damaged branches, and avoid overcrowding your plants. You can also introduce natural predators such as ladybugs or lacewings to your garden.

In conclusion, lerps can be a frustrating pest for cup plant owners. But with the right treatment methods and preventative measures, you can get rid of them and keep your plants healthy and thriving. Remember to always use natural methods first, and only resort to chemical pesticides if necessary.