I have a schefflera which is about 10 years old. it has been a very healthy indoor plant for most of this time. last year it had a bad case of scale which I seem to have beaten. something else seems to be disturbing its young leaves: several have failed to grow beyond a little "nub" on the stem which turns brown-black. others have grown out with severe wrinkles and deformations. I originally thought this might be the scale, but now I'm unsure. there are no insects visible to the eye. any thoughts?
You might want to look "very" closely at the deformed leaves for tiny spidermites. If you have an eye-loop, or a magnifying glass that could help id what pest, if any, it might be.
For inspecting spidermites, it might be easier to slowly lift or look under the leaves. Look for fine webs under direct sunlight or bright light - easier to see. I might have suggested burning from fertilizer with the black/brown new growth, but the deformations sound a bit more hostile.
I have never seen any webs on this plant. and I can't see anything with a magnifying glass. Aside from liquid plant food during the growing season, I have only fertilized it once, quite recently, with an organic bat guano based product. the problem pre-dates the fertilizer. its almost every second leaf that gets hit. here are some snaps. thanks!