Root mealybug control

[mistyhiss]

Hi,

Unfortunately it looks like a number of my succulents have root mealybug.I've binned the infested plants and salvaged the plants which don't appear to have the mealybugs in the soil but to be on the safe side I'm going to wash the roots and repot into fresh potting mix and pots. I understand that if I leave the roots soaking in water for 10 minutes then this should remove most of the mealybugs themselves but that the eggs might linger. Is there a treatment I can apply to the soil once they're repotted to kill off any root mealybugs which might later hatch? Plus aside from improved hygiene and quarantining new plants is there a deterrent to root mealybug which I can apply as part of a maintenance schedule?

Thanks in advance.

[rodsmith]

I usually drench the roots in methylated spirits after washing off all the soil. Leave for a few minutes then rinse the roots in water and leave to dry thoroughly before repotting.

I haven't found a foolproof way to prevent a recurrence of mealy bug, root or surface. As I have only about 120 plants it is easy for me to inspect them regularly and destroy any MBs or eggs that I find. Not so easy with root MB though and I have to remember to lift the pots and look underneath, where you can usually see signs of an infestation.

[Terry S.]

Give the soil a drench with acetamiprid. Once per year should be enough.

[Paul D]

This stuff seems to work as a deterent. I mix some of it in with all my potting mix.
https://www.uhlig-kakteen.de/en/celaflo ... nulat.html

Mealy bugs won't be affected by just water alone. Soapy water or meths will kill them, but not the eggs. You'll need to repeat in about a week's time, then again a week later to get new hatchlings. Spraying with Bug Clear can work https://www.amazon.co.uk/Bug-Clear-Ultr ... B0071QND28. It has a systemic component (acetamiprid) which will stay in the plant for a while. But mealy bugs have become resistant to this in some places.

[gerald]

They can be persistent and almost impossible to spot until it's too late.

The only thing I found to work was Compo Bi 58 and I now use it 2-3 times a season, as a preventative

Good luck

[ralphrmartin]

For some plants, especially leafy succulents like Echeverias, Aeoniums, etc, and even small cacti in genera like Rebutia, the best bet might be just to cut all the roots off, and treat it as a cutting.

[mistyhiss]

Thank you very much to you all for your advice (a few months on from the original post - sorry!) I've thrown away all plants with bad infestations and have treated the remainder with a root drench of Compo Bi 58. All my plants are kept in a conservatory so no harm to insects outside. From what I gather it's pretty strong stuff, so hopefully it will do the trick. Obviously it's tricky to tell how it's working with the root mealybugs, however I haven't seen any thrip crawlers since applying it, which is wonderful as they were becoming a nuisance.

[Terry S.]

I didn't know what this was, so I had to Google it. It is our old friend the neurotoxin Dimethoate in a different guise that still seems to be available in Germany, although withdrawn long ago in the UK.

[Eric Williams]

All the above is exellent advice and it works. Every new plant I get is removed from pot and compost removed. If required I use meths on any pests.So far this particular pest is very low down on my "kill list". Hope it stays like that lol. Cheers