Hi there. I've had this ficus elastica a couple of years now, and over the past few months the leaves have started developing a mottled, textured look that develops into brown spotting on most newer leaves near the midrib (oldest leaves are not affected) and sometimes near edges. There is no sign of pests on this plant or those around it, but I treated with diluted alcohol a few weeks in a row to be sure. I had thought things were getting better but the newest growth has started showing signs of this weird mottling/texturing/browning as well. I fear it might be a fungal infection. Otherwise the plant seems healthy and there's been lots of new growth recently. I don't feel that watering is the issue. What should I do? Thanks!

Check those white dots on the leaf on the right in the second picture. Can you scrap them away with a small knife?

I don't think it's a serious problem but need confirmation.

I think more likely Thrips. They move very fast. They rasp the surface of the leaf and suck up the sap that oozes out.

ElPolloDiablo said:Check those white dots on the leaf on the right in the second picture. Can you scrap them away with a small knife?

I don't think it's a serious problem but need confirmation.

I think just cystoliths? I could be wrong. They don't scrape away.

CPPgardener said:I think more likely Thrips. They move very fast. They rasp the surface of the leaf and suck up the sap that oozes out.

I think you're right. The alocasia that was beside this plant is now showing signs of an infestation. Thankfully the other plants on the same sill seem untouched. I've moved the alocasia to another room and have been treating both the alocasia and ficus elastica weekly with diluted alcohol for going on 3 weeks now. On the alocasia the thrips were very visible, and there are barely any anymore. On the ficus elastica the thrips haven't been visible but the damage definitely is. There are some new leaves on the way on the ficus, so I'm hoping if these remain untouched that means my alcohol treatment is working!

Do you have any additional tips for beating thrips? I've read conflicting advice online about them living in the soil...

They don't live in the soil, only on plants. They do, however, fly and move very fast so they can seem to come from out of nowhere. Also, being small and dirt colored they can hide almost anywhere. If you have a bad infestation and want to get rid of them for months, use a systemic insecticide with imidacloprid. The plants absorb it through their roots and translocate it throughout so it gets all of them even in those hidden places you can't reach.

Much delayed reply, but the diluted alcohol treatment ended up working super well and the ficus is thriving. No more pests!