Scale is...disgusting.
To be fair, all infestations are, but there's something extra creepy and gross about scale. Maybe it's just my trypophobia acting up. Ugly little bumps where they shouldn't be *shudder*
Although it doesn't look like it, scale are insects. Tiny insects that steal the sap from plants (both indoor and outdoor), killing them slowly. Because of how they look, it's easy to mistake scale for a fungal disease or other infection.
How to Recognize Scale
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Scale doesn't have a definitive look. They're generally small. They can be white, black, orange, brown, or a variation that blends in with the plant. They can look rounded or not. They can be soft or hard-shelled.
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One way to identify them is by knowing you'll never see just one, and they usually appear in clusters.
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Scale don't move once they've settled into place and started feeding.
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Sticky leaves that are yellowing and falling off are a sure sign that something is wrong with your plant. If you notice this is an issue, look closer to identify whether scale is at the root of the problem.
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Sooty mold-- black patches on leaves-- can be a sign of scale:
Sooty mold on leaves
Tips on Dealing with Scale
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Scale is easiest to eradicate when in the nymph or "crawling" stage of their life cycle. Unfortunately, this stage is short and easy to miss. If you do catch them at this point, use insecticidal soap or other pesticides to get rid of them.
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Once the insects develop a hard coating, it's much more difficult to get rid of them. It might be easier to simply discard the plant (it sucks, but the scale will eventually kill your plant anyway).
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Scale can spread to other plants, so once you find it on a houseplant, get it away from other nearby plants.
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When you find scale on a plant, start by pruning infected branches, if possible. Dispose of pruned parts right away (don't compost them).
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Use cotton swabs or cotton pads dipped in rubbing alcohol to wipe down the plant, including under the leaves and all nooks. This kills the scale, and wiping the bugs off helps to spot any new ones that show up. Repeat as necessary. For a larger infestation, where applying alcohol by hand is impractical, try organic horticultural oil spray. Apply spray in the evening, every 7 to 10 days until the infestation is gone.
I have a small Greek Myrtle that came to me with scale. I didn't notice the problem for a while and I was really lucky that it didn't spread to any other plants. Since the myrtle was (and still is) small, I used the pruning and alcohol method, and it seems to have worked. I just checked over it again, this time with a magnifying glass, and couldn't find anything suspect (although the pruning led to some weird sideways growth, so I'll have to do something about that). I'm cautiously optimistic that the plant is now scale free.
My Greek Myrtle seems to have recovered from scale... 
Have you ever had to deal with scale on your plants? Feel free to share any tips in the comments!
Further Reading
How to Get Rid of Scale on Plants
How to Get Rid of Scale on Plants in Your Home and Garden
How to Get Rid of Scale Insects on Houseplants for Good!
Cheers,
Aspasia
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Greek Myrtle photos are by Whimsy Bower/Aspasia S. Bissas
