As I was preparing my houseplants to come inside for the winter, I noticed a bad case of scale on my palm.
Crawlers & Female Scales
You are seeing a range of ages of scale in these photos, as scale can have one or two generations per season. The nymphs are hatched from under a female scale and ‘crawl’ to a new location. This is the only time the insect will ever move, so the nymphs are often called ‘crawlers’. Females will find a suitable location and honker-down. She will loose her legs and live under her shell. Male scale develop wings for to get around to all the women, however in most cases, he only lives for a few days.
Scale insects are divided into two categories:
• Soft scales (Cottony maple scale, for example) produce a soft, thin, cottony, powdery or waxy layer over themselves that cannot be separated from the insect body. These scale insects often produce copious amounts of honeydew.
• Armored scales (like these in the photos) have a hard, shield-like cover composed of shed skins and wax that conceals the body but is not attached to the body of the insect.
Treat with horticultural oil or organic insecticidal soap. If you’re going with soap, spray the plant down with water first, as the longer the soap spray stays liquid, the better job it will do smothering the pests.
Just for the record, using dish soap is not acceptable for a cheap substitute for horticultural soap. Now-a-days, the dish soap is not soap anymore, detergent is the main ingredient and modern soap lacks the fatty acids that are helpful in killing the insect. All you will do is dry out your plant!
Another few good tips to aid the recovery of your plant from scale:
- Don’t over-water.
- Don’t fertilize – forcing fresh growth is stressful on the plant and the pests like the new stuff better!
- Place in sunny location.
- Try to remove the honeydew, as sooty mold will grow on it.
- Don’t be afraid to prune when needed – I cut many branches down to just lessen the surface area.
- About once a week, spray off the plant and reapply the soap or oil.
Both new and old scales are seen in this photo
© Ilex – Midwestern Plant Girl