I don't know much about them but I have some too - I don't know if they cause any damage to plants. Birds love them!

If you find out what they are and what to do, please tell me too! I had some like them that I was told were lawn grubs. I watered with lawn-grub poison and it had no effect whatever!

There's lots of information about them on the internet. Try a google search ...

I've been doing more reading, and think this is what I found in my manure delivery on the weekend. Can they get as big as 10cm? Do I have to spray poison, or could I just try going through the heap and picking them out (the manure is currently in 2 black compost bins sitting on clay - I doubt they'd be able to bury into the clay, and the only plants around are some bean and corn seedlings I planted out - the compost bins are sitting in the 'next' area of garden to be made, if that makes sense) so I don't think they have much to live on (except the compost). A friend suggested trying to drown them out - hosing the compost till it is really wet, and they will come to the surface where I could pick them off easily - does anyone have any idea if this would work?

g'day wishful,

i would just pick them out as i find them, they will bury into the clay they ae a pretty tuff grub, i have them in my gardens and as plants aren't suffering i can only guess they do no harm, in my reply to your other post they seem to be interested in eating organic matter in line with earth worms and other things. in plant pots where the organic matter can be depleted fairly quickly like earth worms these grubs are going to be a nuisance. you may find that as the material they desire to eat in the horse poo diminishes they will move down into the ground and seek out another source.

len

I notice that this thread started in July last year but has some current discussion. I think that curl grubs can do a lot of damage; more than many people suspect. The grubs are underground, out of sight and probably responsible for a lot of fatalaties that are blamed on other causes. Right now I have veronicas and penstemons that I can just lift off the ground because they have no roots; all eaten away by curl grubs. A little dig in the soil underneath will usually find a few fat grubs that can be chucked to the birds. A biologically safe and efficient way of getting rid of them is to use nematodes that you can buy through some nurseries. On a larger scale, councils spray nematodes on sports grounds, garden parks, etc. Black flower wasps also hunt them; they are fairly big wasps, with black bodies and metallic-blue wings. I have seen them burrowing into the soil, using some kind of natural ability to home in on the grubs.

not sure if you are all talking about the same grub here, the one that eats grass roots is called cockchaffer. One stage in it's life cycle is a bettle, black about 1/2 inch long, flies inside as well if given the chance. Hard shell. The only solution I have heard mentioned by an agronomist is a pretty heavy poison treatment. It doesn't always work either. Seasonal bug. Ruins pasture for farmers.

Curl grubs eat the roots off the plant, hence retard growth or kill the plant. They especially like veg/edible plants. Very hard to get rid off. The only thing I have found is munns(brand) for curl grubs. It also keeps away ants and kills a few other things. I dig it through the garden bed and pot soil. It seems to keep them under control. If you touch the soil in your pot and it is all spongy and soft, you will have curl grubs. I use on veg plants but try to avoid when fruit or veg is nearly ready to eat.
Hope this is of some help.