On all these plants I have visualized damage and actual thrips insects. To anyone with experience trying to remediate thrips, could you advise what I should just give up on because it's not going to make it? I'm extremely distraught to have this happen, but also don't want to waste time on something that may be beyond saving.

The spider plants (I've removed a lot of their leaves that were very loose and heavily infested) and the syngonium seem to have the most apparent insects.

The philodendrons are all recently rooted cuttings that had been in water immediately next to spiderettes from these infested parents that I didn't realize were dying.

Everything's been sprayed with insecticidal soap and Neem oil combo and placed outside.

Thanks!

My advice will not be popular. But, that is just the way of things I guess. I have a greenhouse full of rare and expensive plants, about 2000 at last count. I don;t fool around with pests, especially THRIPS. I use Orthene. Its an old school organophosphate pesticide that kills immediately. It kills all the adults, and with a follow up spray weekly every 7 days for a month, kills subsequent hatchlings. It gets rid of Thrips, Mealybugs and Scale. You have to be careful spraying it. Wear a mask. Take the plants outside and leave them out until dry. Spray all surfaces, stems, and the soil around the roots. Its a systemic, it gets absorbed by the plant tissue and keeps killing. When you have as many plants packed in as close as I have, you don;t waste time with stuff like alcohol on a Q tip, Neem, etc.

Thanks, Gina! I totally appreciate your need to use pesticides for a valuable collection like yours and I'll keep that in mind. I haven't heard of that specific chemical and wouldn't have known what to get.

None of your plants are to the point of death. You can save them.

I don't see any definitive evidence of thrips in any of the photos you posted. Perhaps you have already effectively eliminated them. The leaf discolorations may have other causes.

@WillC thanks for reaching out!

I based my diagnosis on Google images for thrips which looks and reads exactly as I see on the plants. I know it's difficult sometimes to convey in photos.

I see the yellowish/whitish larval, I guess, stage and occasionally a blackish adult-looking guy. Especially on the spider plants and the syngonium, I continue to see them obviously on the leaves even just after spraying with the insecticidal soap.

The other plants I didn't notice blatant damage, but I had moved those infected plants near them before I noticed the bugs, so I inspected them and saw insects.

It's definitely not aphids. I've had them before, too, and am familiar with observing them in the garden.