Curly grub

[65muzzy]

Discovered last week that 2 of my elms had curly grubs in the soil. So today I repotted them both after I removed all the soil. My question is where do these curly grubs come from as I have always kept the pots off the ground. Is it possible that I bought them with the grubs already in the pots. The first elm that I re potted had about 10 grubs. What can I do so that the grubs do not return. Thanks in advance.

[shibui]

Curl grubs come from curl grub eggs. The eggs are laid by the adult beetles. The adult beetles can walk and fly so they can lay eggs wherever they like, including your pots.
It is possible that they were in the pots but they still get into my pots that I have not bought so just as likely they are home grown grubs.
Several Ausbonsai members have found that potting mix with diatomite seems to stop them coming back. You will find plenty of posts about curl grubs here on ausbonsai - use the search facility upper right

Personally i keep an eye out for the telltale signs of loose soil on the surface and just pick them out when i find them. Insecticide will also work.

[raewynk]

Curly grubs do what I have learnt feed a couple of magpies a little bit of thinly sliced beef, put a couple of pieces close to where you want them to find the grubs and they will eat the little blitters very quick.

I have seen them hone in on the the loose thick pieces of soil, their becks go straight down and up they come with the curly grub.

Stop laughing it actually works try it

My two Magpie's are called Roger and Dodger just in case they get a bit slack on the job.

Regards
Rae

[Aquaman]

Curl grubs are a serious problem in my garden and I have found them very hard to get rid of unless you change your soil to something more gritty.

I repotted most of my trees to a gritty soil and I haven't seen a single curl grub since.

However my vegetable patch has loads of curl grubs. I have now treated it with a pesticide 5 times and they still keep coming back. I dug the top few inches of the vegie patch at the weekend and found 6 of them. Gritty soil in my vegie patch is not an option unfortunately.

So in my experience gritty soil works, pesticides don't work (or at least they don't work in the longer term).

[Boics]

Curl grubs are a serious problem in my garden and I have found them very hard to get rid of unless you change your soil to something more gritty.

I repotted most of my trees to a gritty soil and I haven't seen a single curl grub since.

However my vegetable patch has loads of curl grubs. I have now treated it with a pesticide 5 times and they still keep coming back. I dug the top few inches of the vegie patch at the weekend and found 6 of them. Gritty soil in my vegie patch is not an option unfortunately.

So in my experience gritty soil works, pesticides don't work (or at least they don't work in the longer term).

Sounds like you need to call in Roger and Dodger!

There is lots of evidence in the forums that gritty substrate (Diatomite, Zeolite etc) works as a great deterrent to Curl Grubs.

[Aquaman]

Maybe I could hire Roger and Dodger to come and feast in my vegetable patch for the weekend.

I'll even help do a bit of digging for them. Some of those grubs are buried deeper than a magpies beak.

[Gerard]

I have used a soil mix rich in diatomite for many years and never seen a curl grub until last year.
A group of 3 cedars had one die, I decided to replace it and repot when I found 8 grubs in the soil. The group was purchased a year earlier potted in a commercial potting mix.

[shibui]

I have used a soil mix rich in diatomite for many years and never seen a curl grub until last year.
A group of 3 cedars had one die, I decided to replace it and repot when I found 8 grubs in the soil. The group was purchased a year earlier potted in a commercial potting mix.

Does this mean that diatomite is not the panacea against all curl grubs that we have been led to believe?

[dansai]

I think Gerard may have meant it was in the pot because it was potting mix and not his usual mix rich in Diatomite.

Lucky this fella wasn't in my bonsai pots...... That's a full sized Bic fur reference (It actually looked a lot bigger in the flesh)

Curl Grub.jpg

[bamboos]

Diatomite doesn't kill curl grubs!!
About six months ago I bought a gum which had been raised in a diatomite zeolite mix -- when I repotted it after I bought it( same day)it had six curl grubs munching on the roots.
Steven also had a curl grub in one of his casuarinas ( was posted on Ausbonsai) and he uses a diatomite mix.
I have found if you have a problem with curl grubs then confidor tablets ( or the cheaper bulk version) will fix them.
Sorry to be the bearer of bad news
Steve

[kcpoole]

Diatomite doesn't kill curl grubs!!
About six months ago I bought a gum which had been raised in a diatomite zeolite mix -- when I repotted it after I bought it( same day)it had six curl grubs munching on the roots.
Steven also had a curl grub in one of his casuarinas ( was posted on Ausbonsai) and he uses a diatomite mix.
I have found if you have a problem with curl grubs then confidor tablets ( or the cheaper bulk version) will fix them.
Sorry to be the bearer of bad news
Steve

Interesting find
I moved to Diatomite mix about 6 -7 years ago now because of constant infestation of curl grub, and have only ever seen 1 in or near a pot of mine with this mix. That one was in amongst the surface mulch of leaves and moss and had not gone down into the substrate at all so no root damage.

Can you find the post from Steven you refer to? I have not noticed that at all.
did the Euc have a small percentage of Diatomite in it? to me it would have to be more than 25 - 30% to ensure no grubs will grow. The eggs will get deposited in the mix regardless of what is there, but if the concentration of Diatomite, zeolite, pumice is not high enough, they will survive.

Diatomite does not kill the grubs, but they cannot survive and develop if it is in high enough content

I think Gerard may have meant it was in the pot because it was potting mix and not his usual mix rich in Diatomite.

I read that the same way too

Ken

[65muzzy]

I pot up my bonsai in a commercial mix. What should I do to keep the grubs away? Is a spray or similar available so that I can kelp this under control.

[Aquaman]

Let's be clear diatomite doesn't kill curl grubs. I wasn't suggesting it does.

What diatomite and other more gritty soil mixes do is discourage curl grubs from living in the soil.

Curl grubs have soft skin and like to travel through soft mud-like soils. If your soil mix is gritty because it contains diatomite and other sharper ingredients (like grit or gravel) the curl grub can't dig through the soil.

A friend of mine suggested a good test. Imagine your finger is a curl grub and try to work it deep into your soil. If this is a bit painful and difficult to do the curl grub will probably have the same experience and go somewhere else.

My bonsai soil mix is very painful to stick my finger in and I have no curl grubs. My vegetable patch full of soft mud and there are loads of curl grubs in there.

This is speculation but many people who use diatomite also include some sharp gravel and I think that probably does more to prevent the curl grubs than the diatomite. Most diatomite is quite soft with round edges which won't bother a curl grub unless you have a high percentage of it in your soil.

[bamboos]

Hi Ken
The euc was potted in about 80% diatomite and 20% zeolite ( with a bit of fert)
Steven's casuarina was under the heading of casuarina cunninghamii from ledanta I think it's on the third page --- it's in casuarinas and alocasuarinas sorry I don't know how to post a link to it
Steve

[kcpoole]

Most diatomite is quite soft with round edges which won't bother a curl grub unless you have a high percentage of it in your soil.

All of mine is Very sharp and hard edges no rounded Diatomite in my mix. From what I have heard is that the grubs cannot survive in it because the dust and fine particles created when the try to wiggle and dig thru it affects them rather than sharp edges.
Whatever the actual cause to me is not relevant as I know that a mix with 30% or more Diatomite will most likely have no curl grub in it ever, and a mix with more than 50% I could probably guarantee there is none surviving in the substrate or around the roots within the pot.
I have 100+ pots on my benches and sitting on the ground, and for 7 years I have never seen a Grub within the substrate itself. The ones on the ground will have curl grub under them but not in them

Bamboos, I think you are referring to this post of stevens here
viewtopic.php?f=56&t=6215&p=181090&hili ... ta#p181090
he clearly states that the grubs were living in the Dead wood of the tree ( which they like to do), and not in the soil mix itself. Stands to reason that if the grubs are not in contact with the sharp mix / dust, then it will not affect them

Ken