In 2009 and in 2013, we were hit with all of our maple containing "Cambium Miner" or "flek". These are caused by an insect in the tree and the tree fills in the voids left by the insects, resulting in these blemishes. I literally had to dump a few thousand dollars of wood several times due to this. I went through every maple neck blank supplier I know, both in the US and Canada in search of cleaner maple. At the time, this was the best wood we could get.....fortunately, we have been "Cambium Miner" free for the last three years. Next up is the ash beetle, which is devastating ash throughout the US.
When grading lumber, this is NOT considered a defect. I then had to change my standard from top grade to "billiard grade" with my suppliers, with more than a 100% price increase.
Cambium miner's effect on lumber grade
Emerald ash borer - Wikipedia