Scale on Pothos Plants: 6 Ways to Eliminate & How to Prevent

Pothos plants (Epipremnum aureum) are popular houseplants, well-known for their hardiness, fast growth, and attractive foliage. However, like all plants, they can be susceptible to pests, particularly scale insects.

We will explore the world of scale insects, why Pothos are so attractive to them, and effective methods for eliminating them if you find scale on pothos plants. With some knowledge and diligent care, you can ensure that your Pothos plants thrive, free from these unwelcome invaders.

Understanding Scale Insects

Scale insects are small, sap-sucking houseplant pests that can cause severe damage to plants if left unchecked. They have oval, flat, or convex shapes, often resembling small bumps or scales on the plant’s surface.

These insects belong to the Hemiptera order, which includes over 7,000 species worldwide ¹.

Varieties Of Scale Insects Affecting Pothos Plants

Two primary categories of scale insects can infest Pothos:

Soft Scales (Coccidae)

These insects excrete a waxy substance, giving them a soft, cottony appearance. They are typically larger than armored scales and generate honeydew, which attracts ants and leads to sooty mold growth on the plant.

Brown Soft Scale (Coccus Hesperidum)

This soft scale is a prevalent pest for Pothos. They display a light brown to yellowish hue and are approximately 3-5mm long.

Cottony Cushion Scale (Icerya Purchasi)

These soft scales manifest as white, cotton-like clusters on the plant. They can inflict significant harm to the Pothos if left uncontrolled.

Armored Scales (Diaspididae)

Armored scales (hard scales) possess rigid, protective shells and do not generate honeydew. They are smaller than soft scales and more challenging to dislodge from the plant.

San Jose Scale (Quadraspidiotus Perniciosus)

This armored scale is a common pest of Pothos, looking like tiny, gray, circular casings on the leaves and stems.

Florida Red Scale (Chrysomphalus Aonidum)

These scales exhibit a red to reddish-brown coloration and can cause leaf drop and yellowing when found in large numbers.

Life Cycle Of Scale Insects

Understanding the life cycle of scale insects is crucial in determining the best course of action for their control. Scale insects have three stages in their life cycle: eggs, nymphs (crawlers), and adults.

Egg

Female scale insects lay eggs underneath their protective covering. They can lay up to a couple of hundred eggs.

Nymph (Crawler)

Once the eggs hatch, the tiny, mobile nymphs emerge. This is the most vulnerable stage of the scale insect’s life cycle, as they are susceptible to various control methods. Nymphs will crawl to a new location on the plant, where they will begin to feed and establish a protective covering.

Adult

After molting several times, the nymphs transform into immobile, wingless adults. At this stage, they continue to feed on the plant’s sap and reproduce, completing the life cycle.

Why Are Scale Insects Attracted To Pothos Plants

Pothos are particularly attractive to those insects for several reasons:

• Pothos plants have large, fleshy leaves that provide ample space for scale insects to attach and feed.

• The fast growth rate of Pothos plants ensures a constant supply of new foliage for the insects to infest.

• Pothos often grow indoors, where natural predators can’t reach them. They would otherwise help to control scale insect populations.

• The high humidity levels often found in indoor environments can be beneficial for insects. It allows them to grow and reproduce in large numbers.

• The lack of air circulation indoors can make it easier for scale insects to settle on Pothos plants.

How To Identify a Pothos Scale Infestation

You can identify a scale infestation on Pothos plants by the following signs:

• The presence of small, circular, or oval bumps on the leaves and stems may be hard or soft depending on the type of scale insect.

• Yellowing leaves or wilting of leaves results from the insects feeding on the plant’s sap.

• A sticky residue on the plant’s surface is honeydew secretion (in the case of soft-scale insects).

• The growth of sooty mold on leaves and stems as a result of honeydew accumulation.

• A decline in plant growth and health, due to the insects sapping vital nutrients.

• The presence of ants on or around the plant, as they are often attracted to the honeydew produced by insects.

6 Steps To Get Rid Of Scale on Pothos Plants

Several techniques exist for eradicating scale bugs from Pothos. These methods can also be applied to other pests like spider mites and mealybugs. It is crucial to recognize that using a combination of these approaches may be required to gain total control over an infestation.

1. Manual Extraction

For minor infestations, you can individually remove the insects from the plant. Use a soft cloth or cotton swab soaked in rubbing alcohol or a blend of water and gentle liquid soap.

Gently rub the impacted areas to displace and exterminate the insects. Repeat this procedure every few days until you successfully eliminate all visible insects.

You can also use your fingernails for this task. Be careful not to harm the plant’s leaves in the process.

2. Trimming

If pests have extensively infested the plant, cutting away the affected leaves and stems might be necessary. Be sure to sanitize your trimming tools between cuts to avoid spreading the infestation.

Clear away fallen leaves and debris from the nearby area, as these elements can attract scale insects and additional pests.

3. Insecticidal Soaps

Insecticidal soaps are a secure and efficient remedy for insects on plants. Mix a solution following the manufacturer’s guidelines and spray the impacted areas. Make sure to treat the undersides of leaves, where insects frequently conceal themselves.

Repeating applications may be necessary to eliminate the infestation completely. Don’t apply insecticidal soaps under direct sunlight or in high temperatures, as this could result in damage to the leaves.

4. Horticultural Oils

Horticultural oils, like neem or mineral oil, can suffocate insects, effectively blocking their access to air. Combine the oil with water according to the product’s instructions and use a spray bottle to apply it to the plant’s affected areas. 

Be cautious not to over-saturate the plant, as it may harm the foliage. Similar to insecticidal soap, several applications may be necessary for total control.

5. Biological Management

For those who prefer a more eco-friendly method, consider introducing helpful insects to your indoor garden. Natural predators such as ladybugs, lacewings, and parasitic wasps can assist in maintaining pest populations under control.

These insects can be purchased from gardening supply stores or online vendors. Ensure that you create a suitable environment for these predators, which includes a water source and supplementary food like pollen or nectar-producing plants.

6. Systemic Pesticides

In extreme situations, systemic pesticides can be used to treat scale infestations. However, use systemic insecticides only as a final option, as they can negatively impact beneficial insects and potentially lead to other unwanted side effects.

Stick to the manufacturer’s guidelines for correct application and dosage amounts.

Prevention Of Future Scale Infestations on Pothos Plants

Preventing scale insects from invading your Pothos plants is the most effective approach. Follow these suggestions to minimize future infestations:

Examine New Plants

Before introducing them to your indoor garden, thoroughly inspect new plants for any signs of insects. If you detect any unusual bumps or other signs of an infestation, treat the plant accordingly. Once treated, you can position it near your existing plants.

Maintain Plant Health

A healthy Pothos plant is less susceptible to scale infestations. Ensure your plants receive the proper care, including adequate light, water, and nutrients. 

Clean the leaves to remove dust and debris, which can attract pests. Keep an eye on humidity levels and ensure proper air circulation to create a less favorable environment for scale insects.

Check Your Plants

Often inspect your Devil’s Ivy for any signs of scale insects or other pests. Early detection is key to preventing a full-blown infestation.

Quarantine Affected Plants

If you discover insects on one of your plants, isolate it from the others to prevent the infestation from spreading. Treat the affected plant and check it for any signs of reinfestation before reintroducing it to the rest of your indoor garden.

Use Natural Predators

Introduce beneficial insects to your indoor garden, such as ladybugs or lacewings. That will help keep scale insect populations in check. Ensure that you maintain a suitable habitat for these predators to thrive.

Clean Your Indoor Garden

Keep the area around your Pothos plants clean and free of debris, which can harbor scale insects and other pests. Clean the surfaces of pots and planters and any decorative items in your indoor garden to reduce potential hiding spots for pests.

Rotate Treatments

If you have experienced scale infestations in the past, consider rotating the use of different treatments. That will prevent the pests from developing resistance to a specific control method.

This can help maintain your chosen treatments’ effectiveness in the long term.

References

1: http://cues.cfans.umn.edu/old/inter/inmine/Scale.html. (n.d.). http://cues.cfans.umn.edu/old/inter/inmine/Scale.html