this topic was probably discussed in the past, but i'm a new member and I have never sent a post before. not anywhere! I just discovered the scale creatures on my peace lily. yuck gross! it was bad. I bought some schultz garden safe spray and saturated the plant. my peace lily is enourmous. it took the whole bottle. then I ran my fingers over all the stems and leaves. the nasty things came off. all my plants are in excellent shape. even my peace lily. it has a ton of flowers. i have a bird nest fern. on the underside of the leaves there are these long brown patches in the ridges that are powdery like pollen almost. do you think they also are some kind of critter? what would i look for on my many other plants? i'm going crazy with a magnifying glass. I love all my plants and would do anything to help them! i cannot believe they have yucky things on the and i did not know!! sorry for being long winded. PLEASE help me!
Welcome! It could be powdery mildew. I've never got it on a indoor plant so I don't know how common it is. On my outdoor plants I just cut off the effected leaves.
And the patches on the underside of the fern could be simply the plant trying to reproduce. A photo would help to determine for certain. Ferns produce sori on the undersides of their leaves. It is the fern equivalent of seeds. Look up a couple of good websites on fern sori and you'll likely find photos. I'm including a photo of the sori of Campyloneurum phyllitidis which is considered a Birds Nest fern for your comparison. However, if your plant is a diffent species, it won't look the same. The scale can be a bigger problem. The things lay microscopic eggs that are difficult to eradicate. Plant oil sprays, which I assume is what you used, will often get rid of them But if the eggs are not killed as well they will come back. There are natural predators that will eat them, but they are very costly. One order can cost $100. And in your case, you're likely doing all you can. But keep your eyes out for more. Pick them off and retreat until you are satisfied they are gone.