I recently noticed what looks like small beetles on our dwarf citrus tree. Can anyone identify this abnormality?
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Is this something harmful that I should attempt to treat?
That looks like the worst case of scale I've ever seen. Are the tops of the leaves sticky, and is there more of it on the central rib of each leaf (top and/or bottom)? If so, that pretty much clinches it.
Yes, you definitely need to treat it. You'll find some advice here, but maybe someone has better advice for such a horrible infestation. What I would do is start by wiping it all off with small cloths soaked in rubbing alcohol. When you've gotten rid of all the adults (the brown bumps in the picture) there will still be lots of eggs and larvae. Spray the plant with neem oil or similar to get rid of the kids.
Scale-poo can be hard to clean up from underneath the plant, depending on what it's on.
Make sure this isn't near any other plants that you care about! Frankly, I'm tempted to recommend discarding the plant. Keep an eye on anything that has been nearby - it will "jump" from plant to plant.
Scale for sure. Manual removal means wiping them off. Use a wet soapy cloth and rubber gloves as they will become a mushy slime. You might consider purchasing Lady bugs to do some of the work, especially their larvae. Adults will breed and the babies will be extra hungry. Water the foliage before releasing the ladybugs so they can have a drink after their long voyage. Weekly applications of a safer soap or horticultural oil may also help.