Cacti and Succulent Mealy bug

Hi,

Yesterday brought a tray of Succulents into the greenhouse that had been outside all summer and decided to split a few up, only to find loads of Root mealy bugs on all of them, so the tray was quickly put back out!

Decided to dump most of them but wanted to try and save three individual pots by treating them with a drench of Bug Clear Ultra Vine Weevil (Acetamiprid).

Today we bought three wee cactus from the garden center, good looking healthy plants but when home checked their roots only to find, with the help of a magnifier, faint traces of the root mealy bugs

Have seen various posts on the web and using Acetamiprid as a drench seems common in the UK, though the US folk seem to favour Peroxides and some Neem Oil which is rather messay and sticky as a drench as we found last year.

Also found this method, below, in the British Cactus Society forum which feel sure would kill the bugs but not sure how badly it would affect the plants with such root disturbance and the use of Hot water , gather up to 46c is needed to be effective.

Wonder how folk here treat there plants for RMBs ?

 

I've used the drench, I'm trying it not only for root mealy bugs but the ones on the stems as well, if it works I will be happy.

The Cactus society looks to be information from the 1950s, it would work for a while I have no doubt, but only really possible in spring or summer and on small plants IMO.

I have a healthy dislike of neem oil, probably better used as a fence treatment, but that is just my view.

 

I can't say I've had trouble with root mealy bugs. The stem ones yes, and I dab them with methylated spirits. I'm wondering if that would work on the root mb's too.

 

Yes, have used Meths on Stem mealy bugs using cotton buds or fine paint/artist brushes on both the Cactus in the house and on Phal Orchids.
Some in that British Cactus forum mention drenching the roots in Meths , though not sure if its effective against their eggs ? where the systemic action of Acetamiprid will catch any hatchlings.

Just wondering about what to do with all the spent plants and soil from the tray of succulents, would all the Root MB survive a typical garden compost heap ? or another bag for the council tip ?

 

I'd not drench roots in meths, sounds a bit dodgy to me.

I think it would be ok to put the old compost on the heap, but obviously it depends on what you use the heap for and how long you leave it.

 

The compost only goes back onto the garden, not into the greenhouse or any pot plants, though gather RMB can affect plants in the garden as well, so think we will bag any infected compost and plants ready for the council tip.

 

I've found it in pots of hardy perennials I have outside so it probably lives in the ground too. It devastated a nice Coreopsis in a pot outside for me last year.

 

Probably the difference is a plant in the ground can over come it, whereas one contained in a pot is going to struggle.

 

Thats the catch when bringing tender perennials like Fuchsias and Pelargoniums back into the greenhouse to overwinter.
Will have to be extra careful and remove all their compost and give them a drench with that BugClear Vine Weevil, though its quiet expensive at around £15 a bottle which does go very far when you are talking of drenching.

Don't know of anything else that will touch those Root Mealy Bugs ?

Have tried Neem Oil but agree with Pete, its so messy and sticky, also tried the hot water dips , 46c, though again not really sure if typical greenhouse plants will withstand such treatment, the ones we tried it on took all summer to recover.

 

I have lots of plants that spend summer outside and I bring in during the winter, i don't do anything special to them before bringing in.
I've had vine weevil in a few plants over the years but not to any great extent, obviously some plants seem more susceptible than others.

 

It's only ths Coreopsis that had the RMB, and I didn't bring it in for the winter, it's a hardy plant so I left it outside.
I kept it in a pot because it always rots in the ground here, and now it gets RMB in the pots so I don't think I'll be buying any more of them.