A little background info:
First year bee keeper, I have 2 hives that I set up about 6 weeks ago, they were both started from 5 frame nucs. THey were installed in basic 10 frame hives. I've been feeding sugar syrup from day one. I've also noticed beetles from the first inspection, but not over whelming, maybe 10 or 15 each time. One hive was stronger than the other from the get go but not enough to be a concern.

SHB invades:
Last week I walked to my hive to have a look at what was going on. I wasn't planning on opening them up, just look from a nice, safe, 10ish feet away. I noticed small maggots on the entrance of the weaker hive. Grabbed the suit and lit the smoker. It was awful. So I acted quickly, removed all the frames, 4 were still in great shape with no sign of damage, I threw them in a nuc box I had. About half of the bees were left behind so I put new frames with new foundation hoping to save them. Checked the other hive, no damage, pulled one frame with capped brood and put it in the nuc box with the 4 frames from the other hive.

Today:
Nuc box was toast, pictures below. Turns out my queen went with the nuc, it was the first time I had seen her. She was deformed, her abdomen was pushed in on one side. I assume I squished her at some point.

There were still plenty of bees left in the first hive, but they hadn't drawn out any comb and had no chance of surviving with no queen and no brood, eggs, ect. So I very carefully combined what was left of the first hive, with the stronger second hive. I made sure no beetles, eggs, or maggots went with them.

I first hive seemed to ignore the beetles. Interestingly, the stronger hive always seemed to have bees just chasing them around. Not sure if they were actually able to catch them, but they would constantly chase.

Anyways, I nuked the nuc and all the beetles and disgusting little creatures are dead now.