I'd like to know a bit more please. Would sub-freezing temperature kill the larvae? I have some in a new picture frame which is now in my garage, and we've had sub zero (celsius) for a few nights now. I removed the painting and kept it indoors. Also may some have left the frame to fall to the cabinet below, or flown into the room to land elsewhere?
Both adults and larvae are easy to kill. Freezing temps will affect the larvae faster as they're not so resistant to the cold. But adults can go "dormant" for awhile and come back to life when it warms. Just how long they can endure the cold before they die depends on a lot of things including the species. But the real question is whether or not any of this matters.
You see, the real way to measure any wood with an active beetle problem is to measure how many eggs it has and not how many larvae. You see, eggs will not be killed by cold. And so when it warms they'll hatch to larvae and the process of the larvae feeding on the wood will continue until it's been treated. So if you want to keep the frame, you'll need to treat it with the JECTA GEL or BORACARE we have featured in our article.
As for the cabinet below; adult beetles that may have released from the frame could be anywhere because they fly. And since they're mostly drawn to light, once they release in any home they usually end up around window frames or light fixtures unless it's the middle of the night when they emerge. If that happens, they tend to rely more on their sense of smell and end up crawling into some kind of wood crack close to where they came from.
Here are direct links to the information and products listed above:
Powderpost Beetle Article: http://www.powderpostbeetles.com/powderpost-beetle-control