It sounds like a grub - the larva of some type of beetle. I believe all grubs feed on roots. In the adult stage, the beetles range from destructive through benign to beneficial ... being unable to differentiate one from the other, I toss any that I find (because of their size, I think they're mostly June bug larvae) out to the street where they are usually snatched up by birds before traffic gets them. Friend or foe, I know there are more where they came from, but as long as the plants are looking good, they can't have reached intolerable levels ... and the birds benefit.

Diane

I've come across alot of grubs in my beds, and I normally squash the smaller ones. I did come across some huge mutants, in an old pile of mulch. I freaked out when I saw them, but since they weren't feeding on any roots, I left them alone. They were probably the larvae of these large green beetles (aka: 747's) I've rarely seen. I had never seen one of the mutants in any of my flowerbeds...

i use grub killer. why wait to see that they've destroyed the lawn?

I just assume all the grubs will become Japanese beetles and I kill them with glee.

Many beetles are actually beneficial - the Calosoma Beetle being the best-known to me. Large and black with iridescent green and blue coloring, these predators will climb trees in search of their favorite food: caterpillars, particularly tent and gypsy moth caterpillars. (This info confirmed by Clemson Univ.) From an orgnization in the UK, I read that "...the vast majority of ground beetles are extremely beneficial and important predators which help in the natural control of many garden and crop pests, such as grasshoppers, crickets, termites, aphids, plant bugs, leaf beetles, weevils, wireworms, chafer grubs, butterfly and moth caterpillars, sawfly caterpillars, crane flies (leatherjackets), fruit flies, gall midges, many other fly pests, as well as slugs and snails."

Therefore, I make no special attempt to rid my yard of beetle grubs, but do watch for harmful adults and eliminate them.

Diane

I do not know much about grubs, but I do know that the ones in the mulch pile are the good guys. I rarely kill any insects, since I try to keep the balance of good/bad nature intended. I will occasionally knock down the aphids with a hard spray of water, but I usually have sufficient patience to let the lady bugs find them. Lawns are overrated, and take up time and resources which could be better spent otherwise, IMHO.