Beetle larva

Beetle larva

Observation - Beetle larva . Description: I found 4 of these larvae in some wet but rotten wood today while splitting wood .I think wood is alder or willow . any ideas as to species .It was 27-29mm long and about 8-9mm in diameter.

I found 4 of these larvae in some wet but rotten wood today while splitting wood .I think wood is alder or willow . any ideas as to species .It was 27-29mm long and about 8-9mm in diameter.