Scale. You can remove the scale with a q-tip and rubbing alcohol, or spray with horticultural oil. Scale is difficult to eradicate, so several treatments will be in order. There is most likely more scale elsewhere, such as the branches, so treat the entire plant if you need to. And, if your tree is outside, be sure to keep it in the shade if temps are over 85 degrees, as the hort oil can burn the leaves if temps are over 85 and the tree is in the sun.

Patty S.

What are the little black things? I thought the black things might be baby bugs that turned into the larger yellowish/white thing.

And you're right, I am seeing some of it on the branches leading to the leaf.

I can scrape the 'scale' off the leaf with my finger nail - it comes right off. But perhaps scraping it off doesn't alleviate the underlying problem - is that right?

Where do I find horticultural oil? Can I just use vegetable oil?

Thanks!

No, you cannot use vegetable oil. You can find horticultural oils any place where gardening supplies and chemicals are sold. In the meantime, do some googling about 'hortucultural oils' and why they are so useful for the control of scale insects and the suppression of other pests.

Scale insects can be a challenge to control. Whomever gave you this particular plant needs his/her glasses adjusted, lol. If these pests are on the leaves and stems......I'm just sayin.

Most citrus growers treat plants for pests. BUT pests are constantly on the attack.

Many times as the treatment wears off, there may be residual eggs that hatch, or pests get a foothold at the retail store, so they can become a problem again.

It's not always the grower's fault.