Reply by Nomad62

The beetles’ larvae are in the wood having bored in as newly hatched critters looking for a place to grow up. Their original holes require magnification to see; the larger hole which you saw is the one it used to chew its way back out having grown up. If others are indeed in there, they will chew their way out too. Sometimes they crawl back in, sometimes they fly away and look for a new home for their up-and-coming egg laying job…your wood supply being a happy prospect. Heat is the only reliable way to kill them. Poisons can work too, but no guarantee. The oven trick should work well, so long as the inner “core” of the wood got to 130 degrees f. Be careful of how you store the rest of the wood… it may be wise to burn it if more holes start to pop up.

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