Problems with dwarf dianthus

[daveyp1970]

maggie they sound like root aphids,i dont think theres any way of knowing your plant has them really, i suppose spray with a systemic if your are worried,its what i am going to do.Mine were in my normal soil as well not compost,these were seed grown by me.

[maggiepie]

Dave, I don't think you can buy any sort of systemic in Canada.
It seems that anything and everything that worked at killing pests has been banned.

[Lesley Cox]

Assuming we're talking about the same things, root aphis come in white or creamy/yellow colours, with a sort of powdery substance around them. That's the case here anyway. All the ones I find are the yellow sort and they are usually on potted plants and almost always on Primulaceae, sometimes on Saxifragaceae. I unpotted a plant of Primula clarkei last week and found dozens of them on the stronger roots. They come away easily - I used the tip of a thin metal label  - and seem to leave nothing behind though what their eggs might look like, I don't know. I always find them on the outside roots, where the roots are touching the pots, not within the root mass, which makes them easy enough to dispose off.

My course of action nowadays is to sprinkle a little suSCon green around the roots and either plant out or repot. I've never found them on a plant previously infested but treated in this way.

It surprises me that they would attack dandelions. Most nasties go for the most rare/difficult/treasured plants one has.

[maggiepie]

Lesley, the dandelions I pulled up mostly had very big roots, like small parsnips.
The critters were wall to wall around the roots, starting from the top with less towards the bottom.
So close together they were almost overlapping.
I just used my fingers and squished them.
The dandelions pulled up easily. Only time I have had weeds pull up so easily was in spring when the ground has just thawed.
We had had a great deal of rain during spring and early summer but the dandelions that were infested were in one small area, even the tiny ones had some of these things on them.
3 feet away, there was no sign of any on the dandelions I pulled up.
Haven't seen one since and hope I never do.

[Rick R.]

I also have had what seems to be root aphids (white) on one year old dandelion roots.  Only a couple dozen or so per plant, though.

[John85]

Lesley,
What is suscon green,please?What is the active substance?

[Lesley Cox]

John it's a rather nasty stuff in tiny green balls and with an unpleasant smell. I'll leave you to look up the active ingredient on the internet but it is dangerous if not used correctly and we are not permitted to purchase it now except with a qualified agricultural contractor's certificate. It is spelt suSCon green (I think) and I believe it is a german product. It is absolutely lethal against underground things like root aphis and vine weevil grubs and also against narcissus fly. I always put a pinch among new daff bulbs either in the ground or in pots of Narcissus or Galanthus. I also always wash my hands after using it.

[Gerry Webster]

To the best of my knowledge, 'suSCon green' is not available to amateur gardeners in the UK & probably also the EU.

[maggiepie]

In case anyone is interested in seeing what these things look like.
Just pulled up a couple of dandelions.
Not as many as there were on others but enough to see.
It seems that the dandelions that have these aphids come out of the ground easily when you pull.
A few fell off while I was taking pics and some tiny red ants scooped them up and carried them off.
I kid you not.

[Lesley Cox]

Those don't look like mine at all Helen. Mine have no visible legs or feelers, just a little yellow body covered in a powdery substance. I'll take a picture next time I see some. They are very squishable though.

I'm not surprised Gerry about suSCon Green in the UK. It's no longer available here either to amateur gardeners and I'm hoarding my remaining supply and only using it onthis susceptible to certain pests, like Narcissus fly. In 1993 when I was last in the UK and brought back plants, I had to have them dipped before they came home but the substances which our MAF required them to be dipped in, were no longer permitted under EU regulations. So they came home undipped and had to go through the process immediately I arrived in Auckland. Best not discuss the results of that exercise. My blood still boils.

[Rick R.]

Helen's aphids do look just like mine did.

[Lesley Cox]

So I wonder what mine are then? Maybe mealy bugs? I'll photograph ASAP but I don't want to go unpotting primulas to find some.

[John85]

Helen,
I wonder if the ants were taking the aphids away to eat them or to breed and "milk" them as they do with the foliage aphids to get the honey dew.

[maggiepie]

John, I am pretty sure the ants are farming the aphids.
Am now paranoid that the aphids might develop a liking for clematis roots.

[Stephen Vella]

With a lot of toxic chemicals going off the shelf I have been using more and more often organic sprays like the chillie and garlic sprays bought at most garden centres. It really works. I had drench some pots that had root aphids. I even tried it on some ants and it works!

Also neem oils are good as a contact insecticide Ive used it on lace bugs and great for killing mites.

cheers