Bonsai set back #1

[Rubberbandman]

Morning all.
I had two mugo pines that were home depot 75% off buys last fall.....got them into training pots before october with no root trimmings and only removed dead branches....alll went well over the winter and spring, but heres where it got ugly...both have had some sort of bug that has drilled a hole about 2 inches above soil level and i suspect has bored its way into the heart of the trunk.
1 mugo made its way to the firepit the other is on life support, I have tried to inject some pyretherin liquid into hole...only time will tell.
What bug does this?
Thoughts?
B.

 

[Vance Wood]

That would be a bore and probably fatal. Congratulations for spotting it most people would blame their location for their failure claiming that it was where they lived not what got into the tree. See if you can find out the culprit and find a defense against it.

 

[Bonsai Beech]

Probably bark beetles; they leave holes like shot. Not sure what the treatment is to kill them.

 

[GGB]

The set backs never stop. It's freaking brutal out there. sometimes I'm amazed anyone can even keep a finished tree with the way my stuff gets tagged up by finches, squirrels, beetles, mites and wet cold springs. Keep marching soldier

 

[Bonsai Beech]

It's a jungle out there man!