Scale or mealybugs

Sticky residue with small brown shell-like bumps or white cottony tufts means scale or mealybugs.

Diagnosis

Scale or mealybugs

What's happening

Scale insects look like small, flat brown bumps clinging to the branches and trunk, while mealybugs appear as white, cottony tufts tucked into the branch joints. Both pierce the plant to feed on its sap and excrete a sticky residue called honeydew, which coats the needles and nearby surfaces and can turn black with sooty mold. They weaken the plant and cause needles to yellow and drop.

How to fix it

Isolate the plant. Dab the visible scale and mealybugs directly with a cotton swab dipped in rubbing alcohol to kill them on contact, then wipe the residue away. Follow up by coating the whole plant — branches, joints, and needle undersides — with neem oil, and repeat the neem treatment weekly for several weeks until no new bumps appear. Check nearby plants, since both pests crawl to neighbors.

What fixes it

  • Neem oil for pests — Neem oil disrupts scale and mealybug feeding and breeding; reapply weekly until the bumps stop returning.

This is general guidance based on common symptoms; individual plants vary.

Reviewed June 2026 · how we check this