Red mite on orchids

Red mites on orchids are another serious threat to the health of your plant. These pests can cause significant damage, leading to weakened plants, reduced flowering, and even death. In this article, we will take a detailed look at red mites on orchids, their signs, control methods, and preventive measures to keep your orchids healthy and blooming.

What is a red mite?

Red mites are small arachnid pests that cause significant harm to orchids by feeding on their sap. They are typically reddish or brown in color and prefer to live on the underside of leaves, where they are less noticeable. These mites thrive in warm and dry conditions, and their presence can quickly lead to weakened plants and reduced ornamental value.

Life cycle of the red mite on orchids (brevipalpus spp.)

The red mite is a common pest that affects orchids and other ornamental plants. It belongs to the flat mite family (tenuipalpidae) and is characterized by its small size, orange-red body, and slow movement. Its life cycle consists of several stages, with development depending on temperature and humidity.

Egg stage

eggs are oval, smooth, and orange or reddish. They are laid on the underside of leaves, along leaf veins, or in bark crevices. The duration of this stage is 5-10 days, depending on temperature (faster at +25…+30°c). Eggs are resistant to most chemical treatments, complicating pest control efforts.

Larva stage

the larva emerges from the egg with three pairs of legs and a light orange color. It begins feeding on plant sap immediately after hatching. This stage lasts 3-5 days. Larvae feed mainly on young leaf cells, causing yellow spots to appear.

Protonymph stage

the larva transforms into a protonymph, gaining a fourth pair of legs. Its body becomes more elongated, with a bright orange or reddish color. This stage lasts 4-6 days. Protonymphs actively feed, causing significant damage to leaves and pseudobulbs.

Deutonymph stage

the protonymph molts into a deutonymph, resembling an adult but smaller in size. This stage lasts 4-7 days. Deutonymphs continue to extract sap from leaves and flowers, severely weakening the plant.

Adult stage (imago)

the adult mite has an oval, flattened body about 0.3-0.5 mm long, orange or reddish. It is relatively immobile and prefers the underside of leaves. Adult mites can live for up to 3-4 weeks under favorable conditions (humidity below 60%, temperature above +25°c). They feed on plant sap, leaving dry, discolored spots that eventually turn brown and crusty.

Factors affecting the life cycle

temperature: optimal development occurs at +25…+30°c. Development slows below +20°c.
Humidity: low humidity (below 60%) promotes rapid reproduction. Higher humidity (around 80%) slows mite development.

Signs of red mite infestation on orchids

Early detection of red mite infestation allows you to deal with the problem faster and more effectively. Here are the main signs of infestation:

• Formation of reddish or brown spots: reddish or brown spots may appear on orchid leaves and increase in size over time. This is a direct consequence of mite activity, as they pierce plant cells and suck out the sap.
• Yellowing of leaves: orchid leaves begin to turn yellow as mites suck nutrients out of them. Gradually, the yellowing can spread to the entire leaf, eventually leading to its death.
• Slow growth: infested plants begin to grow slowly, flowering may stop, and new leaves and roots develop with delays.
• Cracks on leaves: feeding by mites can lead to the formation of cracks and deformations on the leaves, which is a sign of severe damage.

How to get rid of red mites on orchids?

Getting rid of red mites requires a comprehensive approach to completely eliminate the pests and prevent re-infestation. Here are the main control methods:

1. Manual cleaning: at the initial stage of infestation, you can use a damp cloth or cotton swab soaked in soapy water to wipe the leaves and remove the mites. Pay special attention to the underside of the leaves, where mites usually hide.
2. Using acaricides: acaricides such as fitoverm or aktara can help effectively kill mites. These products target both the mites and their larvae. It is important to follow the application instructions and apply the product several times at intervals of 7-10 days for complete eradication of pests.
3. Neem oil: neem oil is an effective remedy against red mites. It can be used as a spray by mixing it with water and a few drops of soap. Spray all parts of the plant, including the underside of the leaves.
4. Increasing humidity: mites prefer a dry environment, so increasing humidity around the orchids can help in the fight against them. A humidifier or regular misting of orchids (without water stagnating in the leaf axils) can help create less favorable conditions for mite development.
5. Isolation of infested plants: if one plant is infested, isolate it from other orchids to prevent the spread of mites. These pests can easily move to neighboring plants, especially in crowded conditions.

Preventing red mite infestation on orchids

Prevention is the best way to protect your orchids from red mite infestations. Here are some recommendations to help prevent the appearance of pests:

• Regular plant inspection: regularly inspect your orchids for the presence of mites. It is especially important to check the underside of the leaves and axils where pests may be less noticeable.
• Maintain humidity levels: keep the air humidity at 60-70%. Red mites do not like humid conditions, so increasing humidity can prevent their appearance.
• Maintain cleanliness: regularly clean orchid leaves from dust and other contaminants that can contribute to the appearance of pests. Use a damp cloth to wipe the leaves so that they remain clean and healthy.
• Isolation of new plants: new plants brought into the home should be kept in quarantine for several weeks to ensure they are pest-free. This will help avoid infesting other orchids in the collection.

Conclusion

Red mites on orchids can cause serious harm to your plants if not addressed in time. Early detection of infestation signs—such as reddish spots on leaves, yellowing, and slowed growth—will allow you to take action quickly and save the orchid. Using acaricides, neem oil, increasing humidity, and isolating infested plants will help effectively deal with the pests. Adhering to preventive measures and regular inspections will ensure the health of your orchids and their beautiful blooms.