Phaseolus vulgaris Fine Webbing - Causes & Fixes

Jump to cause: Two-Spotted Spider Mite Infestation Bean Leafroller (Phytometra sp.) Low Humidity/Drought Stress

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Two-Spotted Spider Mite Infestation

Tetranychus urticae are common pests on bean crops that feed on the underside of leaves, secreting silk as they move and feed. The fine webbing is a hallmark sign of an established colony draining the plant's nutrients.

Very Common

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How to confirm: Hold a white piece of paper underneath a leaf and tap the leaf to see if tiny crawling dots fall onto it.

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1 Immediately spray the plant, especially the undersides of leaves, with an organic insecticide to eliminate the spider mite colony and their webbing.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

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2 Prune and dispose of heavily infested or dead leaves to reduce the pest population and prevent further spread to healthy foliage.

3 Increase humidity around the plant and ensure proper airflow, as spider mites thrive in hot, dry conditions.

Flora Premium Plant Mister

Spray Bottles

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Bean Leafroller (Phytometra sp.)

The larvae of certain moth species roll the edges of Phaseolus vulgaris leaves into tubes using silk webbing to create a protected microhabitat. This results in visible silken 'tunnels' or rolled leaf structures.

Common

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How to confirm: Gently unroll any folded leaves to look for small green caterpillars inside the folds.

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1 Manually remove and destroy any visible rolled leaves or silk tubes to disrupt the larvae's habitat and prevent further egg laying.

2 Apply an organic insecticide spray to the plant to target any remaining larvae or eggs.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

3 Monitor the plant regularly using a moisture meter to ensure the plant remains healthy and resilient against pest stress.

GROWIT Soil Moisture Meter - Blue

Water Meters

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Low Humidity/Drought Stress

While not a direct cause of silk production, extremely dry conditions accelerate the lifecycle of spider mites and can cause fine, desiccated leaf fragments to stick together via residual plant exudates.

Common

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How to confirm: Check the soil moisture levels and use a hygrometer to determine if the ambient humidity is below 40%.

build How to fix it

shopping_cart Recommended Products

1 Inspect the undersides of leaves for tiny moving dots or webs to confirm if spider mites are present; if found, treat with an organic insecticide.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

2 Increase ambient humidity around the plant to prevent further desiccation and slow the mite lifecycle.

Flora Premium Plant Mister