Curl grubs and diatomite

[Glenda]

Hi people,

Having read about using diatomite dust as an insecticide, I was wondering if anyone using diatomite(particularly at high ratios eg 100% or 80/20) has ever found curl grubs in it?

Glenda

[anttal63]

Usually my chinese elms in an organic mix were full of them. I will soon find out. Repot next weekend possibly.

[kcpoole]

Hi Glenda
My 2 favourite topics
After many years of suffering Curl Grub infestations in every tree I have ever had, I have moved to a mix of 2/3 Diatomite / 1/3 Zeolite
this is my 4th year using it, and have Never seen a curl grub in any pot with it yet!

Ken

[Grant Bowie]

i think in general; the grittier (whether diatomite or gravel etc)the mix the less curl grubs.

Grant

[Bretts]

I remember reading that the curlgrubs are eating the organic bark and such. The roots just get in the way. So if there is no bark the idea is there are no curl grubs.
I have hardly ever had a problem with them myself though.

[Taffy]

I remember reading that the curl grubs are eating the organic bark and such. The roots just get in the way.

Don't believe that's quite accurate Brett. I used to have quite a big problem with them here in Maryborough. The bark in the potting mix wasn't touched, but they would just about demolish a root system on a tree in a very short time. I'm not talking about the little ones some people have. The mongrels I was getting here were huge. Just imagine eight of these in a Bonsai pot:

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[Bretts]

Holy Crap

[Grant Bowie]

Holy Crap

What he said and more!

[Bretts]

Seems I was mistaken Tman

The beetles lay their eggs in the soil during late spring, summer and early autumn. The eggs hatch into larvae that feed on plant roots or decaying organic matter.

From this page
http://www.annettemcfarlane.com/pestID.htm
It also has a picture that looks the same as yours and states these large ones are rhinoceros beetle larvae. Cool beetle from such an ugly youngen

Edit: Guess the grit and diatomite or inorganic material in general makes it harder for them and not really worth the trouble.

[Taffy]

The beetles lay their eggs in the soil during late spring, summer and early autumn. The eggs hatch into larvae that feed on plant roots or decaying organic matter.

That may well be the case in the wild where there is quite a bit of decaying matter, but I guess we have to take into account that we are creating a micro-climate in a Bonsai pot with all those luscious tender feeder roots all bunched up together in a nice moist environment. Late spring, early summer here in Maryborough can be very dry, so obviously the Rhinoceros Beetles would be looking for a more ideal place to lay their eggs, so what better place than a well tended Bonsai pot?

[Bretts]

Thats a good point too Tman. I guess if they eat roots then that nice pad or roots at the bottom of a pot would seem very tempting

[Graeme]

i think in general; the grittier (whether diatomite or gravel etc)the mix the less curl grubs.

Grant

Grant, I use a mix pretty close to "Dot's Mix" and as TMan could tell you - I have been known to grow some pretty damn good Curl Grubs in the past.

[kcpoole]

Holy Crap

What he said and more!

Faaaarrrrrrkkkkkkkk!!!!!

Jesus what the hell do you feed them on! Steroids?

Ken

[Taffy]

This is Queensland - we do everything BIG up here.



Even the Magpies won't have a go at these monsters - but my dog loves them

[anttal63]

SHOTGUN!!! TMAN blast the - - - - - - -. Thats some serious arse grubs...