Howdy, neighbor! Hey, I had this exact same thing happen to me last year, only it was in some seeds I got from a lady at work ~ and yes, they were hibiscus too. Like you, I didn't want to store the seeds with bugs in them in the house or even in my workshop. So, I just planted them out in the fall (now) bugs and all. I figured the seeds would naturally fall to the ground at this time of year anyway, and overwintering outdoors should put paid to the bugs.
I don't know what kind of bugs they are, but I think they are attracted to the hibiscus seeds as I had the exact same ones you describe.