Cyclamen Mites

Cyclamen mites are tiny, translucent pests scarcely visible to the naked eye. Native to the Mediterranean, they have become a widespread problem in many parts of the world, especially greenhouses.

Host Plants

Cyclamen mites (Stenotarsonemus pallidus) are known to infest a variety of plants. Some of the notable host plants for cyclamen mites include:

• Cyclamen – The name ‘cyclamen mite’ derives from this plant being one of their primary hosts.
• Strawberry – Especially problematic for commercial growers, leading to deformed berries and flowers.
• African violet – Infestations can cause distorted and discolored growth.
• Delphinium – Flower buds turn brown and do not open. Young leaves may show stunted or twisted growth.
• Geranium – Leads to stunted and twisted growth.
• Gerbera – Leaves become twisted, curled, or crinkled. The flowers can become discolored or may not open at all.
• Dahlia – Affected plants can display curled and distorted new growth.
• Chrysanthemum – The mites can hinder bud development and flowering.
• Ivy – Both English and other varieties can host cyclamen mites.
• Snapdragon – Mites can cause the leaves to curl and the flowers to become discolored.
• Begonia – Infested plants often show stunted growth with curled and distorted leaves.
• Pepper plants
• Tomato plants

Many other ornamental and vegetable plants can be affected by cyclamen mites. The actual list is quite extensive, and the severity of the infestation can vary depending on the plant type, growing conditions, and presence of natural predators.

Regions impacted

While they originated in the Mediterranean, cyclamen mites are now found in many parts of North America, Europe, and other temperate regions, especially in greenhouses or indoor growing environments.

Description

Cyclamen mites are minute arachnids, barely visible to the naked eye, measuring a mere 0.2 mm to 0.3 mm in length. Due to their minuscule size, a magnifying lens is typically required to spot them. They are semi-transparent, orange-pink and shiny, with an elliptical shape, and four pairs of legs. Their tiny size often makes their presence in plants go unnoticed until the damage is evident.

These mites prefer high humidity and cooler temperatures, often thriving in the concealed areas of plants such as buds, leaf axils, and under the leaves. They avoid direct sunlight, making the shaded and protected parts of the plant their prime habitat.

Cyclamen mites feed by piercing the plant’s cells and sucking out their contents, leading to significant cellular damage. Their saliva is toxic to plants, which intensifies the harm and results in the characteristic twisted, stunted, and deformed growth patterns on infested plants.

Regular inspection of susceptible plants, especially during cooler and humid conditions, is crucial to detect and manage these mites early.

Life Cycle

The life cycle of cyclamen mites is relatively short, allowing for rapid population growth under favorable conditions. Understanding this life cycle can aid in effective management and control measures. Here’s an overview:

• Eggs: Adult female mites lay their eggs in concealed plant parts, especially in young, tender tissues like the undersides of leaves or within buds. The eggs are translucent and oval-shaped.
• Larval Stage: After a few days (typically 3-5 days, depending on conditions), the eggs hatch into six-legged larvae. This larval stage is brief, lasting for just a couple of days. During this period, the larvae begin to feed on the plant.
• Nymphal Stages: Post the larval stage, the mites move into two nymphal stages: the protonymph and deutonymph. In each of these stages, the mites resemble miniature adults, possessing eight legs. Like the larval stage, nymphs feed voraciously on plant tissues. The combined duration of these nymphal stages can range from several days to a week.
• Adults: Once the mites pass through their nymphal stages, they become mature adults. Adult mites continue to feed, mate, and lay eggs, perpetuating the cycle. The adult lifespan typically lasts for 10-30 days, during which females can lay up to 50 eggs.

The entire life cycle—from egg to adult—can be completed in as little as 10-14 days under optimal conditions, which include cooler temperatures (60°F to 70°F or 15°C to 21°C) and high relative humidity. Such a quick turnaround means that infestations can arise swiftly and get out of hand if not detected and managed in time.

Regular monitoring of susceptible plants, especially during conditions favorable to mite development, is crucial. When populations are high, the lifecycle can be even more rapid, leading to quick and substantial damage to plants.

Damage and Detection

Damage:

Cyclamen mites can cause severe damage, primarily to herbaceous plants. The damage they inflict is due to their feeding behavior. They pierce plant cells and suck out the contents, leading to cellular disruption. The symptoms include:

• Distorted Growth: This is one of the most noticeable damages. New growth, especially at the tips of plants, may look twisted, stunted, or swollen.
• Leaf Curling: The leaves of infested plants can curl inward or downward.
• Bronzing: The leaves or affected parts might take on a bronze or russet hue, especially on the underside of leaves.
• Bud Damage: Flower buds can become discolored, remain closed, or drop prematurely. When they do open, the flowers might appear deformed.

Detection:

Given their minuscule size, cyclamen mites are challenging to detect with the naked eye. Here are some techniques and signs to aid in detection:

• Magnification: Use a hand lens or microscope to inspect suspected plant parts, especially young growth and buds.
• Symptoms Observation: Look for the characteristic damages mentioned above, such as distorted growth, bronzed leaves, and bud malformation.
• Tissue Discoloration: Sometimes, an infestation may cause plant tissues to darken. This is especially noticeable in buds that turn black and don’t open.
• Environmental Conditions: Cyclamen mites thrive in cool, humid environments. Plants situated in such conditions should be monitored closely.
• Isolate New Plants: When introducing new plants to a garden or greenhouse, isolate them initially and check for signs of mite damage to prevent introducing an infestation.

Early detection is vital in managing cyclamen mite infestations. Due to their quick lifecycle and potential to cause significant harm, gardeners and growers should be proactive in monitoring and employing preventive measures.

Prevention and Control

Effective prevention and control of cyclamen mites require a combination of cultural, biological, and chemical methods. Here’s how you can manage and prevent cyclamen mite infestations:

Prevention:

• Regular Monitoring: Frequently inspect plants, particularly the new growth and flower buds, for signs of cyclamen mite damage. Early detection can help mitigate the spread of mites.
• Quarantine: When introducing new plants to a garden, greenhouse, or indoor space, quarantine them for a few weeks to ensure they aren’t harboring cyclamen mites.
• Optimal Growing Conditions: Cyclamen mites thrive in cool, humid conditions. Ensure good air circulation and avoid overcrowding of plants to reduce humidity.
• Sanitation: Remove and destroy infested plant parts. Regularly clean greenhouses and indoor growing spaces.
• Resistant Varieties: If available, choose plant varieties that are resistant to cyclamen mites.

Control:

• Biological Control:
  • Predatory Mites: Several mite species, like Typhlodromus bellinus and T.reticulatus, feed on cyclamen mites and can be introduced to affected areas as a biological control measure.
• Chemical Control:
  • Miticides: If an infestation is severe, specific miticides labeled for cyclamen mite control can be used. It’s crucial to rotate products with different modes of action to prevent mite resistance.
  • Insecticidal Soaps and Horticultural Oils: These can be effective against cyclamen mites when applied thoroughly and directly onto the mites. They work by smothering the mites or disrupting their cell membranes.
• Cultural Control:
  • Pruning: Remove and dispose of infested plant parts, especially when the infestation is localized.
  • Water Spray: A forceful spray of water (4 parts water to 1 part rubbing alcohol) can dislodge some of the mites from the plants, especially in the early stages of infestation.
• Temperature: Cyclamen mites are sensitive to high temperatures. Immersing infested plants in water held at a temperature of approximately 111°F (44°C) for about 15 minutes can effectively kill cyclamen mites without causing harm to most plants.
• Integrated Pest Management (IPM): Use a combination of practices – cultural, biological, and chemical – to manage cyclamen mite populations effectively. This approach minimizes harm to beneficial insects and reduces the chance of mites developing resistance.

Remember, always read and follow label instructions when using chemical treatments, and consider the potential impact on beneficial insects. Regular monitoring and proactive practices are the keys to keeping cyclamen mite populations in check.