I bought new plants (water lettuce) a couple of months ago, and like a month ago I noticed a couple of bugs in my fry net. I killed them, but they keep coming back. I couldn’t find anything online and I don’t know if they are harmless or not. It’s hard to kill them one by one, and they didn’t go away after I removed most of my lettuce. Is it okay to just leave them be or is there something I can do to get rid of them?