I have some osage orange that has clearly been infected with some bugs. I don't know what kind though. This surprises me as I have never had bugs get in my osage before. I cut and use a lot for bow staves. I have actually even heard people say that bugs can't even get to the stuff on account of its hardness.
So what are these bugs? They have fairly small holes, a little bigger than the point of a ballpoint pen. They got in mainly on portions where I didn't get the bark stripped off (I was in no hurry, as I have never had this problem before). Most of their holes are in the sapwood, but a few go quite deep into the heartwood, some maybe an inch or so. They also seem to have stopped now that the wood has sat around for about two years.
(Sawing and Drying Forum)
From contributor D:
If I remember correctly Gene has mentioned a certain type of beetle that leaves holes similar to a Powder Post Beetle (around the size you mentioned) but that prefers wetter wood (I can't recall the name right off). I know PPB's prefer dryer wood, so I doubt it would be them.
I have heard of other bowyers having what they call grubs (supposedly some kind of wasp larvae) to infest their osage while it’s drying. Typically they eat the sapwood and only go a couple of growth rings into the heartwood (which sucks for bowmaking of course), but I don't know of the size hole they leave. Have you seen any of the bugs?
I would still like to know just what these guys are though. Fortunately the trees I have are large enough that I can cut down far enough to avoid the holes and the wood is useful yet for bows. I was very worried at the first, because this tree is undoubtedly the best osage I have ever seen, three 8-10 foot sections of clear log on the trunk! That never happens – you’re lucky to get one section completely clear and rarely get two, at least around here.
So ID'd by a pHD in entomology - I first thought it was the Locust Borer and then we both thought it was the Mesquite Borer but microscopy and autopsy of the critter says it's Painted Hickory Borer (all three species look identical to the naked eye). It's the same bugs as get in the mesquite here and if it's possible the bois d'arc has a heavier infestation than mesquite. You can stand eight feet away from the logs and it sounds like a bowl of Rice Krispies with hundreds of little mounds of dust on the ground.