Scale Insects
Risk near you, next 48h
See whether your local forecast favours this disease right now.
When it strikes
Treat, then re-check in 5–7 days
Pick off the worst material, apply the organic option below, and look again after five to seven days. If the spread continued, escalate rather than repeating the same treatment.
Carried by insects
An insect moves it plant to plant, so controlling the carrier matters as much as treating the symptom. Check for the vector before assuming the plants infected each other directly.
Safe to compost
No pathogen carries over on this material, so it can go on an ordinary heap with the rest of the garden waste.
When and where to look
Scout the planting while temperatures hold between 18°C and 34°C.
The signs that lead here
About
Scale insects are immobile sap-suckers that attach to stems and leaves of fruit trees, citrus, houseplants and shrubs under protective waxy shells, slowly draining vigour.
Symptoms
Small brown, tan or white bumps along stems and leaf veins that do not rub off easily; yellowing leaves, dieback, sticky honeydew and sooty mould.
Organic Treatment
Scrape off light infestations, dab with rubbing alcohol, and spray horticultural oil to smother crawlers and adults. Encourage parasitic wasps and ladybirds.
Chemical Treatment
Horticultural oil timed to the crawler stage, or systemic insecticide for severe woody-plant infestations.
Prevention
Inspect new plants, prune out heavily infested wood, apply dormant oil to fruit trees, and keep plants healthy and unstressed.
Related problems
Scale Insects risk by location
Each location has a month-by-month profile computed from the weather archive: how many hours a year actually meet this disease’s thresholds.