Rhododendron argyrophyllum Fine Webbing - Causes & Fixes

Jump to cause: Two-spotted Spider Mite (Tetranychus urticae) Thrips Infestation Southern Yellow Pine Webworm

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Two-spotted Spider Mite (Tetranychus urticae)

These microscopic arachnids thrive in warm, dry conditions and feed on the undersides of Rhododendron leaves, injecting toxins that cause stippling and characteristic fine silk webbing. The silver-leafed foliage can lose its luster as the cells collapse due to feeding.

Very Common

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How to confirm: Hold a white piece of paper under a leaf and tap the leaf sharply to see if tiny moving dots fall onto the paper.

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1 Immediately spray the plant, especially the undersides of the leaves, with an organic miticide to kill existing mites and larvae.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

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2 Increase local humidity and avoid leaving the plant in hot, dry air to make the environment less hospitable for spider mite reproduction.

Flora Premium Plant Mister

Spray Bottles

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3 Check the soil moisture levels regularly to ensure the plant is not under drought stress, which can trigger mite outbreaks.

GROWIT Soil Moisture Meter - Blue

Water Meters

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Thrips Infestation

Thrips feed on the epidermal cells of Rhododendron leaves, causing silvery or necrotic scarring. While they do not produce large webs, their presence can sometimes be accompanied by very fine, almost invisible silken strands during certain life stages.

Common

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How to confirm: Inspect the undersides of the silvered leaves for tiny, slender, elongated insects moving rapidly.

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shopping_cart Recommended Products

1 Apply an organic insecticide spray to the plant to eliminate active thrips larvae and adults.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

2 Inspect the undersides of leaves and remove any heavily infested foliage to prevent further spread.

3 Use yellow sticky traps near the plant to capture flying adults and monitor the population levels.

Super Ninja Fungus Gnat Traps - 30 Pack

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Southern Yellow Pine Webworm

While more common on conifers, certain webworm species can create silk structures on woody shrubs like Rhododendron to protect their larvae. This webbing is typically thicker and more structured than spider mite webs and may contain visible caterpillar fragments.

Common

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How to confirm: Gently pull the webbing apart to check for small green caterpillars or silken cocoons inside.

build How to fix it

shopping_cart Recommended Products

1 Manually remove visible webbing and caterpillar fragments from the plant using gloves to reduce the immediate pest population.

2 Apply an organic insecticide spray to the affected areas to target any remaining larvae or eggs within the silk structures.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

3 Monitor the plant regularly for new silk structures or caterpillar presence, especially in the spring and summer months.