It was from the pyrethrum that done this not the bugs.
I wouldn't give up on it. I had a plant that looked hopeless. I nursed it along and got some of the best bud ever. It was also a great way to learn things.
To me it looks like a ph or nute (lockout or overfeeding, or imbalance) problem. But, if you're absolutely positive those spots didn't exist prior to your use of pyrethium, then that's actually good news. If it's one-time damage due to burning from insecticide, that means your environment's ok and new growth should be ok.
But, to me it looks like your soil might be slow-draining (not enough perlite, if any.). Keeping soil too wet can look like nute lockout because ph rises as the soil dries. If the soil doesn't drain well and stays too wet, that would limit the ph range the roots will experience (along with other problems).
For plants in early veg I use a Hot Shot No Pest strip if I have a bug problem. I keep it in a heavy ziplock bag. I'll pull it out for 6-8 hours a day, for about a week and that kills anything. (I wouldn't use it in a flowering tent. Not sure if flowers would absorb the poison. I won't use it in mid veg either. Just the first 3 weeks if there were bugs in the soil when I started.).
