They're tiny, largest was ~4mm long and <1mm wide. Any ideas what they are?
I ended up pulling the plants, didn't notice anything moving in their roots but I rinsed most of the soil out, set them in tupperware and soaked them in miticide/insecticide and am leaving them to dry out before replanting later this week.
Dumped all the soil, lava rock, and top dressing from the pot in to a garbage bag and sprayed the tray and pot down with the miticide/insecticide
Rinsed those off, and now I put the pot in the oven for a bit just to be extra-sure. Might be a bit much, and I know I damaged a bunch of spines on one of my favourites (The Oreocereus
), but I'd rather kill them myself than let the bugs do it and risk them spreading.