Scale insects guide image
Plant pest guide

Scale insects

Signs: Brown or tan bumps on stems and leaves, sticky residue, and slow decline.

Signs: Brown or tan bumps on stems and leaves, sticky residue, and slow decline.Organic control list: Prevention note: Inspect woody stems and leaf ribs.

Quick facts

Signs: Brown or tan bumps on stems and leaves, sticky residue, and slow decline.

Organic control list:

Prevention note: Inspect woody stems and leaf ribs.

  • Scrape small infestations gently.
  • Wipe with alcohol on a cotton swab.
  • Prune severe stems.
  • Use horticultural oil when temperatures are safe.

What to do next

  • Isolate the plant if it is indoors or in a crowded collection.
  • Inspect leaf undersides, stems, soil surface, and new growth.
  • Physically remove what you can with water, wiping, pruning, or hand-picking.
  • Use the lowest-risk organic control that matches the pest.
  • Repeat checks because eggs and hidden life stages often survive the first treatment.

Watch-outs

Do not spray first and identify later. The wrong treatment wastes time and may stress the plant.

FAQ

How do I use this plant pest guide?

Start with the light, soil, water, symptom, or purpose notes on this page, then make one careful change at a time.

What is the biggest mistake with Scale insects?

Do not spray first and identify later. The wrong treatment wastes time and may stress the plant.

When should I get more help?

Get local help if the plant is valuable, symptoms are spreading quickly, or outdoor disease and pest problems may affect nearby plants.