elm tree grub

This morning a hokido princess elm of mine that rapidly died (or mostly died) last week for no apparent reason was being watered by my wife and a large branch fell off and within the trunk was a large white grub. The trunk diameter is about 1/2 inch and the grub is about a 1/4" in diameter. Does anyone have any idea what this could be?
thanks

Hi!

What's a "grub"?

regards,
jun


Got it. it's a beetle larva.

same things kills two branches of my flowering Lantana. Didn't know at first whats slowly killing the tree, then I found out after cutting the dead branches something (the larva) is eating it from the inside. No pesticide can kill it from the outside/bark.
I chopped off all the affected branches, then change my soil.

regards,
jun