I had an outbreak and large spreading infestation in my outdoor collection of cactus. I hit them with a systemic, but, kinda expensive. So, I approached it like you did: repotting them.

I pulled them out of their pots and got as much old soil off with water jet and a stick. Then I sprayed them with permithrin til dripping, roots esp. Let them dry in the shade for a day. Rechecked bugs were all dead then repotted them. Don't reuse old soil - bug eggs. Permithrin gets them, but, if the other infected plants aren't addressed, the babies will float right back again. I had to spray the dracaena's nearby as the tops were full of mealies.

I'm not sure how well this works, but, I mixed diatom powder to the top half of the mix. It supposed to pierce the exoskeleton and dehydrate them. Use food grade if you opt for this.

They can be controlled, but , you have to be diligent for about 1-2 months to make sure you got all aduts and nymphs.
Hope you beat the invasion.

Rubbing alcohol and a cotton ball always worked for me.

Zackey, they are in they soil, so that method isn't working for me.

Aztcqn, thanks so much for the thorough explanation. I ended up buying a spray by Bayer and some diatomaceous earth as a back up. I wish I would have read your post before I went to the store. But it's definitely a lesson learned! I will from now on take every plant I buy out of their pots and inspect it's soil. I'm just glad I had all of them set to the side (because I was going to repot them) so the mealy bugs didn't spread to all my other plants! Thanks again! :)

Hey Sbgibbons,
You are welcome.

I learned alot about same on these boards, then gained wisdom through my own battle.

Glad my experience was helpful.

I've been fighting root mealybugs for over a year. The washing and repotting didn't end it, the spraying didn't end it.

Today I bought systemic. If this doesn't work I'm seriously considering starting over with new plants.

I'm sorry to hear that! Is it all of your plants? If it is, I'm sure that must be devastating. It's only 3 new plants of mine, which I had separated from the rest of my plants, thank goodness!

I'm just wondering what these look like? Do they look like mealies just in the soil? Or do they look different?

I'm pretty sure soil mealy bugs are the same thing as regular mealy bugs. It just means you have them in your soil and you can see a lot of eggs and they are just harder to get rid of (I'm pretty sure that's the difference). I'd post a picture of mine, but you can't really see anything because I'm already starting to see improvements. I may have jumped the gun when I switched to the Bayer spray.. Maybe the alcohol was working after all. But I'm still going to continue to spray for another month or so. :)

Google pictures! It's pretty interesting.

Thanks

Ugh, I just brought home a pot of succulents with mealybugs on the stems and leaves. I was planning on repotting them anyway. How did you know they were in the soil as well?

You can look at the drainage holes under the pot and see if there are tiny white balls (eggs) visible in the holes or pull the plant out of the pot and look at the roots and see if there are mealy bugs or eggs surrounding the roots. You can Google pictures of "soil mealy bugs" to get a better idea of what I'm talking about.

Thank you! Knock on wood, but it looks like the bugs were just on the upper parts of the plants.

carlyd73 , I understand the frustration. I found that the permithrin killed them on contact. I mean that stuff kills ticks! I would soak the roots and plant before you repot them the next time. I would leave them out of pot for almost a week to check if the critters were actually dead and if not spray one more time, wearing gloves keeps it from getting on your skin.
You have to catch all the cycles of adults and then nymphs which means one or two months of weekly spraying til they're gone.
Check other plants, non-cactus, are not infested as well and contributing to the re-infestation. I know how exhausting this battle is, believe me. I hope you do get the upper hand and not have to dump the plants.