I have had "thrips" on my cacti before and have successfully controlled them in the past spraying spinosad. This year I noticed a different kind of thrip like insect ive never seen before and applied the spinosad spray. These were much more stubborn and seemed to be hatching in much larger numbers. I could have gotten on top of the situation earlier but had always had great success with the spinosad spray so was not in a great hurry.

I decided to try a different approach and bought some insecticidal soap. This was definitely effective in eliminating the pests but also seems to have irritated the outer skin of my beautiful plants. They will be ok but I wanted to make a public service announcement that potassium salts at 1% concentration is too strong for some cactus species to not have visible reaction to the chemical.

Thanks for the heads up. I haven't tried the stuff. I've had problems with thrips in the past, and the last few years have been getting some damage from tiny green grasshoppers. In the past I used to set off a bug bomb and that was it for the thrips. The last few years I've tolerated a bit of damage, not wanting to use insecticide again. This year I dusted the tops with diatomaceous earth. Remains to be seen how effective that will be.