Quote Originally Posted by Ron-NY View Post
I doubt if fungus gnat larvae ate that leaf. They primarily feed on fungi, algae and decaying plant matter. However, the larvae will feed on plant roots and leaves resting on the growing medium surface but that leaf edge does not sit on the medium.
I have similar damage on leaves of my plants... they're all indoor plants... I've never seen any other pest appear besides the odd stink bug (and we ruled him out), but after running the gamut of everything that could POSSIBLY be chewing on my leaves, I had to conclude it was the fungus gnats. (The adult ones, that is... at one point I had a full-blown infestation, and my plants' leaves started looking particularly beaten and battered at that point.)

I think the larvae eat the decaying bark, but I've seen adult ones landing on my leaves, and I'm pretty sure that after some nibbling they can inflict the type of damage we're seeing here in this thread. The damage to my leaves has been cut down CONSIDERABLY since I started using the traps, and I suspect it will stop altogether once I start with the gnat treatment stuff.

I think fungus gnats can inflict more damage than they are originally given credit for. When the edges of your leaves are getting slowly nibbled on, over time you wonder what the heck is going on, especially when you've confirmed there are absolutely NO other pests present.

Anyway, I'm not ruling out that it could be something else... I just happened to notice that she said she thought she had a gnat problem... which would suggest she'd seen gnats... which would suggest she has fungus gnats... which is a problem that should probably be treated anyway, so it might be best to start there and see if it does any good. Then, if the damage continues, she can pursue other possibilities... but at least the gnats will be gone!

That's just my humble opinion. But from what I've seen fungus gnats do, over time and in groups they can really mess up those leaves, especially around the edges where they're easiest to chew.

I have damage from my gnats that looks just like what I see here. So if that pest has already been identified, why not go after it first?

Just my two cents...