How to treat cottony cushion scales on yard trees?

How to treat cottony cushion scales on yard trees?

Controlling cottony cushion scales on yard trees requires a combination of winter sanitation and spring control.

Winter and early spring (dormant season) control

This is the critical prevention period, the most work but the most effective:

1. Scrape old bark, use a scraper or wire brush to remove loose, cracked bark on trunks where scales overwinter.
2. Remove egg sacs, find white, cottony egg sacs on trunks, scrape them off, and burn them or drop them into boiling water.
3. Clean the ground, remove all fallen leaves, weeds, and pruned branches from under the tree.
4. Whitewash trunks, apply limewash to the lower trunk (lime:water:salt ≈ 1:5:0.1) to protect against both pests and frost.
5. Sticky barrier bands, wrap sticky insect tape around the trunk 30-50 cm above ground to prevent nymphs from climbing up.

Spring nymph emergence (critical control period)

• When nymphs begin hatching and moving in March-April, spray dinotefuran-containing household insecticide on trunks and main branches.
• Focus on bark crevices and branch crotches.
• For tall trees, concentrate on the inner canopy and lower branches.
• Spray every 10-14 days, 2-3 times consecutively.

Growing season management

• When a few insects are found, wipe them off with a damp cloth or brush.
• Prune dense branches to improve light and air circulation.
• Spray dinotefuran-containing insecticide on the ground under trees to prevent fallen nymphs from climbing back up.

Precautions

• If trees are very tall and household sprayers cannot reach, hire a professional tree care company.
• Wear gloves and a mask when spraying.