8 Common Orchid Plant Bugs, Pests, and Diseases

Orchid plants are a popular choice to grow at home offering rich symbolic value and lots of uses and benefits. However, despite their relatively easy care needs, even orchids can be susceptible to pests and diseases. Knowing what these problems can look like and how to treat them is essential for ensuring this plant thrives. Continue reading to learn some of the most common orchid pests and diseases, as well as ways to prevent them.

Dealing With Common Orchid Plant Pests & Diseases – The Essentials

Orchids can develop infestations of pests like mites, whiteflies, aphids, and scale insects. Common diseases for this plant include botrytis, southern blight, and powdery mildew. Depending on the issue, you can use water, insecticidal soap, neem oil, rubbing alcohol, and similar treatments. 

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The Most Common Orchid Plant Pests and Diseases (and How to Identify Them)

Here are some of the most common pests and diseases that numerous types of orchids may develop (including popular Vanda orchids, Moth Orchids, Jewel Orchids, and Lady’s Slipper Orchids). We’ll cover everything from the causes and symptoms of each issue to the best ways to prevent and treat them.

Southern Blight

Southern blight, sometimes known as collar rot, is a fungal disease that can affect orchid plants. The fungus attacks the stem and roots and sometimes the plant’s leaves, causing the tissue to wilt and decay. You may notice symptoms like yellow leaves or yellow or white fungal growth around the base of the plant.

The main reasons southern blight develops in orchids are high humidity and poor air circulation. The fungus thrives in wet environments and can quickly spread from one plant to another.

If you suspect your orchid has southern blight, there are several things you can do to treat it. The most important thing is to remove all of the infected tissue from the plant. 

Additionally, you’ll want to ensure the affected plant doesn’t touch your other plants, as the infection can spread quickly. Then, you can treat the plant with a fungicide or a diluted bleach solution.

Powdery Mildew

Powdery mildew is a fungal infection that often affects orchids in the summer months. It appears as a white powder on the leaves or stem and can cause leaves to turn yellow or brown. It’s unlikely that powdery mildew will kill your orchids, but it can impact their health and growth.

Powdery mildew can develop due to excess humidity, poor air circulation, overwatering, or overly shaded conditions. It can also emerge due to weakness or injury or if your plants are too closely crowded together.

You can treat powdery mildew with a fungicide or a baking soda solution. Remember, following the directions on the product you use is crucial, as overuse can harm your orchid plant.

Botrytis

Botrytis, or orchid blight, is a common fungal issue in humid environments. The fungus appears as a gray or white mold on the flowers, leaves, and rhizomes of the orchid plant.

The most common reason botrytis may develop is if an orchid plant is over-watered or in an overly humid environment. Botrytis can also develop from wounds on an orchid plant or exposure to contaminated water or soil. If you notice botrytis growing on your orchid plant, you can treat it with a fungicide or a baking soda and water solution.

Aphids

Aphids are small, often green or black insects with antennae and soft bodies. They can damage orchids by sucking sap from their leaves and flowers. This weakens the plant and leads to yellowing or browning of the leaves, stunted growth, and even death.

You can remove aphids by squirting them with a strong stream of water. Additionally, you can kill them by using insecticidal soap or horticultural oil. 

Remember, aphids like to hide, so it’s essential to treat the entire orchid, including the undersides of its leaves. You should also repeat the process a few times, as aphids can be tricky to remove completely with one treatment.

Mealybugs, Scale Insects, and Whiteflies

Mealybugs, scale insects, and whiteflies are all common orchid pests. They can cause serious damage to the plant, resulting in weakness, reduced growth, or even death.

Mealybugs are tiny, soft-bodied insects that typically have a white or grey coating. You may find them feeding on the sap of orchid plants, causing leaves to wilt or die.

On the other hand, scale insects are small, hard-bodied insects that attach themselves to the stems or leaves of orchid plants. They often appear as small, round bumps on the plant and can cause wilting or death.

Finally, whiteflies are tiny insects that have a powdery white appearance. They reproduce rapidly and live on the underside of a plant’s leaves. 

Now, you can remove each of these pests from your orchid plants with a strong stream of water or a damp cloth. If the infestation is severe, you may want to use an insecticide to remedy the issue.

Spider Mites

Spider mites are another common pest in orchid plants. Despite their microscopic size, they can cause significant damage, stunted growth, or even death if left untreated. 

Now, spider mites can be difficult to see with the naked eye. However, you can identify them by the web-like patterns they create between leaves. They can also cause the underside of an orchid’s leaves to turn silver, and the tops of leaves to develop yellow or brown spots. 

This pest may develop in orchid plants if the environment is too dry or dimly lit. You can remove spider mites from orchid plants by spraying them with water or horticultural oil.

Leaf Miners

Leaf miners can include flies, beetles, moths, and grubs. These types of insects lay eggs on a plant’s leaves. Then, they feed on the tissue by creating tunnels, or mines, through the plant. These mines can warp or destroy an orchid’s leaves, flowers, and stem.

Now, if your orchid is infested with leaf miners, you should remove and dispose of the infected leaves. You can also use a pesticide to kill the larvae. Finally, you may need to install a physical barrier between the leaves and the flies, like a net or row of sticky tape.

Fungus Gnats

Fungus gnats are small, black insects with wings and antennae. They are attracted to warm, moist soil environments. 

Fungus gnats may fly around your orchids, leaving behind droppings that can cause the plant to deteriorate. They can also harm your orchids by spreading plant diseases.

You can remedy this issue by covering your orchid’s soil with a thin layer of sand or diatomaceous earth. Or, you can try pouring a small amount of vinegar or alcohol onto the top layer of soil. If necessary, you can find insecticides specifically formulated for fungus gnats.

Pesticide and Insecticide Options

Next, let’s take a look at some pesticide and insecticide options you can use for treating your orchid plant. We’ll cover both chemical and natural alternatives to make sure you find the right solution for your needs. 

Horticultural and Canola Oil 

Horticultural oil and canola oil can effectively treat various orchid plant pests. Plus, they are safer than chemical insecticides for both humans and the environment.

These oils work by smothering and killing the pests infesting your plants. They are most effective in removing tiny, young pests, but you can also use them to remove mature insects. 

Insecticidal Soap 

You can use insecticidal soap to control or prevent various orchid plant pests, including aphids, spider mites, whiteflies, mealybugs, and scale insects. This type of product is especially effective against soft-bodied pests.

Despite how the name may sound, insecticidal soap is chemical-free. So, it’s a great choice if you’re looking for a safe solution for your orchids. You can buy this product pre-mixed or make your own at home using a mixture of vegetable oil, water, and liquid soap. 

Pesticides

Pesticides can treat a variety of common orchid pests. However, it is important to read the label carefully to ensure you’re using the right product for the pest you are trying to control.

Now, you can use pesticides as either a soil drench or foliar spray. A soil drench is when you mix the pesticide with water and then pour it directly onto the soil around your plant. A foliar spray is when you combine the pesticide with water and then apply it to the plant’s leaves.

Sticky Traps

Sticky traps are a glue-based material with an insecticide and aroma designed to attract pests. You place them around the area so they can trap insects before they reach your plant.

These traps are suitable for treating mites and beetles or detecting the presence of other insects. Additionally, they’re an excellent choice for preventive care, as they won’t negatively affect your plant. 

Recommended Pest Removal Products

Here are some options to consider when looking for solutions for treating orchid issues.

• BioAdvanced Neem Oil
• Safer Brand Insect Killing Soap Concentrate
• Grower’s Ally Fungicide
• Stingmon Sticky Fruit Fly and Fungus Gnat Traps

How to Use Pesticides and Insecticides for Orchid Plants

It’s important to follow the packaging directions for any pesticides or insecticides you use on your orchid plants. Unfortunately, some products can do more harm than good if you don’t apply them properly. 

For example, you’ll want to use horticultural oils with caution, as they can also harm or kill beneficial insects. Apply these oils only when there is an infestation of pests, not as a preventative measure.

Managing Pests and Diseases 

Luckily, you can prevent many orchid pests and diseases by providing the right growing conditions.

Remember, orchids need bright, indirect light and regular watering (we generally recommend not watering orchids with ice cubes), around once or twice a week. However, good soil drainage (and a suitable orchid plant potting vessel) is essential to prevent excess moisture, as this can create an optimal environment for pests and diseases to develop.

You’ll also want to avoid exposing orchids to cold drafts or extreme temperatures and fertilize monthly during the active growing season to encourage reblooming. For more, see our essential guide to where to position orchid plants in the home.

Wrapping Up

Orchids are great plants to grow, but it’s essential to be aware of the pests and diseases that can affect them. With proper care, orchids can live for many years to come. By knowing what to look for and how to treat common issues, you’re sure to keep these plants healthy and happy. Use this information to guide your orchid care and enjoy beautiful blooms for years to come.

If you’re looking for your next orchid plant, see our in-depth guide to the best plant shops delivering orchid plants nationwide.

For more, see our essential guide to caring for orchids whilst you’re away or on vacation and everything you need to know about orchid plant care after they finish blooming.

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