Thermite,
That's one of the least affected boards, just to illustrate the holes.
Overland, I am a miller and kiln operator located in NC, and I am a subject matter expert in this area.
For gooseneck trailer decking, I presume that your oak boards were milled at 1-5/8" green? IF so that is around a 2 month run in a conventional or DH kiln, and around 4 months in a solar kiln.
Your grubs will die off as the lumber dries naturally. They will not stay in dry lumber - only green, so they are not really a concern.
The small holes appear to be either lyctid or ambrosia powder post beetles. You can tell the difference by closely looking at the sides of the holes. If they are stained black, they are from ambrosia beetles. On the other hand, if there is no stain on the sides of the holes - ie just natural wood color - then they are from lyctid powder post beetles.
Like the grubs, ambrosia beetles will leave the lumber automatically as it dries. Lyctid, on the other hand - will stay in dry lumber for up to 7 years before boring out and laying their eggs - repeating the cycle. They are your biggest concern.
As others have mentioned, heat sterilization is the best way to kill any pests in lumber; however you don't want to heat sterilize green lumber. The reason why is that you will cause it to check internally and it will lose a lot of it's structural integrity. Unfortunately, it is not typically cost effective to kiln dry oak trailer decking boards. You can air dry them for 12 months or so and then put them in a kiln for a week to sterilize, but that's a lot of hassle.
For trailer decking, an inexpensive, effective preservative (and bug killer) is to saturate the boards with either used hydraulic oil or ATF. Neither one will contain the carcinogens of used motor oil, and they are also a lot cleaner to work off of.
White oak is water resistant, so you will be limited on how deep the treatment will penetrate, but it can still be effective. What I'd suggest is that you lay the boards down upside down and keep them saturated with the used hyd/atf fluid for a few days, then install them and treat the "show side" the same way. This should not only kill the powderpost beetles, but will help to preserve the oak for 7 - 10 years - more if you re-treat it every couple of years.
Borate treatments such as Timbor (we recommend a 15% solution) are also effective, but they will leach out of the lumber long term and not provide the residual rot protection that the hyd/atf will.
A great lumber treatment is concentrated copper napthenate (CuNap) thinned in diesel fuel. This will also kill any bugs in the lumber but with white oak the depth of penetration will still be limited. I've found that the used hyd/atf is the best compromise between cost and effectiveness.
Best of success to you.
Scott