Aphid Damage

Arright. So I don't know if this damage was really caused by aphids (or the suspicious little worms I've recently spotted), but there is some damage towards the bottom of the plants. I can't figure out which of the following scenarios could have been the cause:
A> Aphid and other pests
B> My various sprays, home-made and other
C> It might just be natural
I'm hoping for scenario C. I know that part of the process here is that the whole plant will die in Autumn. If this browning is just an early signal that that's what happening, then that would be excellent. If it's my spraying that's caused it, then as a precaution I've put a hold on all spraying for the time being until the source can be found. However, if it truly is aphids/pests I'm screwed and I fear there's not much more I can do against the aphids.

Here is a wilted birdhouse gourd.

Here is the ball of a large dipper. You can see some aphids, but also the dimples and pock marks the aphids have created. Luckily, this gourd has a twin right next to it that is virtually untouched.