Borer identification help

[BigJim2185]

Looking for some help identifying a wood borer in central Maine. Emerging from pine sawn roughly 4 years ago. Adults are aprox 1" long and a metallic dark blue color. They leave an exit hole about 1/4" in diameter and create a fine powdery frass. It appears larvae were active under some bark that was left on, and adults are emerging from sawn edges of bark or sapwood very close to the bark. 

There should be a picture attached; I believe this is the culprit. 
Thank you for your time and any help. 




 

[Doomsday]

Sounds like something from the Buprestidae family, also known as "metallic bark beetles" or "flat-headed borers."

Couple questions:
-What is the shape of the exit holes, circular or more oval?
-Were you able to see the galleries (tunnels chewed by the beetles) in the heartwood and sapwood, or just the bark/cambium?

I have seen these before in a cabin built of lodgepole pine. 30 years after construction they started emerging. The eggs can stay dormant all that time.

Do not let logs sit on the landing any longer then necessary, and be sure to kiln-dry as soon as possible. They are very attracted to disturbances in the forest such as harvesting, wind events, wildfires, etc. and may travel miles if they pick up a scent of stress pinenes/turpenes (sent out by the tree).

Also, they are secondary bark beetles. Unlike primary borers they require the tree's defenses to be down before attacking. This could be damage to the roots cause by equipment, it could come from drought, or the trees could have been attacked by a primary boring species. They alone should not infest healthy trees or cause mortality.

Hope that helps. Sadly the damage is already done, and I don't know of any treatments once they begin to emerge.

[BigJim2185]

Thank you for the help. I also suspect it is a buprestidae beetle, but I have not had luck narrowing it down any further.

Exit holes are ovicular.

Unfortunately, this lumber is in a structure, and I do not have much visibility. I can tell you that the cambium layer was clearly the focus of feeding at some stage, and the adults are emerging from galleries that head for deeper wood.

I am trying to determine whether I am dealing with something that will reinfest after this generation.

Also, these beetles emerged from a thin strip of exposed window header visible because there is not yet trim. There is very little bark in the structure - I would estimate less than 2sqft spread over a few thin strips on a couple members - but what is left on is behind Sheetrock or sheathing. It is possible there is another little pocket of these beetles in an inaccessible area of the structure, and I am wondering if there is any chance of spread if they emerge into a stud bay, etc. It is a heated and dry home, and all lumber was air dried for years if that is relevant re: possibility of reproduction.

Thanks again.

[Doomsday]

There are only two families of boring beetles it could be: Buprestidae or Cerambycidae. There are countless species within those families, not all of which have even been classified or named. The oval shaped exit holes are a sure sign of buprestidae. They are the only two families which will bore deep into the wood. Most bark beetles stick to the cambium layer and only engravers (Scolytidae, I believe) will make exposed galleries in the very outside of the sapwood.

The infestation should be limited to one generation. They will desperately seek a green tree, which should be necessary for reproduction. So they may chew through whatever they can find in an attempt to get outside, but they should not reproduce.

[BigJim2185]

Thanks for the reply. I appreciate the info.

[LarchMan]

I'm a little late to the party on this thread but it is definitely a Cerambycid of some kind, not a Buprestid, tough to ID from a picture for most species.  Doomsday is right that it won't re-infest wood that is dried and bark-free.

[SwampDonkey]

Agree with you Larchman, I would rule out buprestids. The antenna is too long.