>>1014061Some do. However, the act of spraying them off is normally enough for the survivors to move on. The ones that die, die because of water damage and things on the ground eating them. They are niche insects, remove them from their niche and they have a hard time getting back. Normally, aphids only relocate when carried by ants or when they have wings to fly. Thus, the long march back up to the top of a plant, where the tender new growth is, can be more than they can accomplish
>>1014064General flow chart: Once overwatering is ruled out, habitual underwatering needs to be ruled out (usually indicated not by yellowing or wilting [acute] but by reddening of the leaf tips). After that, you need to think about using fertilizer, as it can be a deficiency. I suggest taking new photos a couple days from now, of the same leaves. Then comparing them on your computer and seeing if the yellowing is getting worse. If it is, add some diluted coffee water the next time you water them (1 part coffee to 1 part water.) Once not enough fertilizer is ruled out, over fertilizing needs to be looked at
Check,
Underwatering: Acute sudden wilt for short term, purpling/reddening for long term (the latter is difficult to tell on purple/red leaf pepper varieties)
Overwatering: yellowing of bottom leaves
Too little fertilizer: growth is slow, yellow spots between leaf veins begin
Too much fertilizer: Acute sudden wilting, long term browning of tips
Disease: yellow/black/brown spots between leaf veins begin.
Pest: Acute wilting (root attack, fungus gnats, moles, grubs, etc), half the leaf tip wilts/browns and curls (leaf hopper egg sting), top wilting (aphid or sap sucking bugs)
Old leaf age: yellowing then browning or just browning then falling off
Since your soil is dry and you've already added fertilizer, I'd just water them and compare photos in a few days. If you think you've over fertilized, you can just flush the fertilizer out by flooding it with water for 5 minutes or so
