Two-lined Spittlebug, adult. Next time, start your very own new thread rather than hitchhiking on one that is 6 years old and of a different subject. You'll get more attention to your question PLUS we love to see new posts and new people.

I would say to coax some of these bugs onto a piece of paper and take pictures of them. I have never heard of any herbs like this or any other plants for that matter, dying in a few hours after looking great just hours earlier. The only time I have ever seen anything like that was a few hours after spraying Spectracide weed and grass control. I am talking about the non-selective weed control with diquat dibromide, and on certain weeds it will cause significant visible damage and discoloring within a few hours of its a hot day outside especially. Its possible they just dried out and began wilting.

There are hundreds of these here in Taiwan. They are cicadas. Here is a good video from David Attenborough: https://www.youtube.com/watch?v=tjLiWy2nT7U

Vaporvac; Often the sawfly larvae are UNDER the leaves. And yes, most of the time, it affects so few roses as not to be worth spraying or fussing over. Dogkitten, I'm pretty sure that's NOT a ladybug larvae. Your spots are mostly just random damage, nothing to worry about, but the yellowing is a little concerning. How often are you watering?...it could be a symptom of keeping the pot too moist or poor drainage.