We lost 4 of 5 colonies this past Spring due to an "old" determined black bear (350 plus Boar). The warden who finally trapped him after four raids said he had likely done it before, especially since he went right through the electric fence all four times, including the one time I got a shot off.
I use a solar fencer rated for ten miles and enclose a 12 x 50 ft yard along w/ a 6' wood fence on N/W side
I think a lot depends on the BEAR. A young will be repelled, an old boar who's been around a bit may not care, after all, he's going to get stung. What's a little jolt compared to that? (w/ exception to Allen ;)
The latest Bee Culture has an add for a product called NITEGUARD Solar. A weather proof solar powered RED light flash that begins at dusk ending at dawn. Lasts three years for $19.99. May be worth 20 bucks. Claims to ward off all kinds of critters, including BEARS.
, and no I'm not selling them. I might buy one though :).