While growing chili plants indoors and lately holes in the leaves and brown spots have started to appear. Images:
There are no bugs visible on the leaves. The plants are grown indoors, have ample sunlight and are grown with expanded clay pebbles below the layer of soil.
Related questions on gardening.SE, but doesn't look like my plants:
EDIT: On a much closer inspection I did indeed find small black critters - probably aphids, judging from other images on the web. I have sprayed the plants with a solution of dish soap and canola oil - now we wait! ;-)