Beautifly? Shedinja? Quiver Dance left and right? You make NU out to be a piece of cake. This Bug team would get ripped apart in NU. Do you have any idea what something like Camerupt or Emboar could do to this team? This team needs to focus less on desperate sweep attempts, and more on reliable team members that can actually take a hit.
Accelgor looks good. Have you considered Final Gambit on it? It's a REALLY good move for taking down the opposing lead,as anything with less base HP than it will be KO'd. Other than that, though, it looks good. I'd rather use Whirlipede for a NU Bug-type Spikes lead, as it has pretty mighty defenses, but the downside is that it has less offensive potential. Keep the Focus Sash on Accelgor, but if you lean toward Whirlipede, use Evolite.
Beedrill is about as good as it will get, but man, Beedrill is vile in NU; horrible. Not as bad as Butterfree, but it's pretty "down there". If you wanna use it, then use Poison Jab. It gets STAB, and would be stronger than a neutral hit from a powered-up Acrobatics, anyway. Both would have their perks, but it all comes down to that sash, which a simple change over to Leavanny could rid of, thanks to the superior stats and better sweeping ability. Maybe use a Life Orb for Beedrill, if you're feeling gutsy. For Leavanny, anything forextra power will do, from a Choice Band to a Muscle Band.
Get that abomination of a booster off of Masquerain! Jeez, Masquerain is far from the best user for it. It's hard to set up Quiver Dance on it,thanks to the minimal bulk and bad typing, so just put a Choice Specs / Scarf on it and go all-out. Replace Quiver Dance with Ice Beam; it still has its use against fellow Bug/Flying types. Maybe even think outside the box and use Hidden Power (Fire), which could also help against Steel, Bug, and Ice-types.
The only adjustment I'd make to Shuckle is to add Wrap or Sand Tomb to his moveset; take out Sandstorm. Power Split and Mud-Slap are useless if the foe simply switches (Which they can and WILL do, as soon as Power Split is used), so use Wrap right from the start. The only downfall is that Mud-Slap can't hit Flying-types or levitaters, and Wrap can't hit Ghost-types, so take your pick.
Shedinja only needs one little adjustment: Dig. Dig can fend off those pesky Fire-types or (If you think strategically) force a switch. Other than that, it's just a coin toss, so good luck. Personally I'd use Armaldo here, as it's a great bulky sweeper that can really pack a punch in NU. It's a beast if it switches in right, and compared to other NU bugs, it doesn't even need setup.
Beautifly. No. Easily the worst fully-evolved Bug-type in the game. If you need a good supporter, go with Illumise! It has priority support, thanks to Prankster. Protect and Encore could be a fun combo. Light Screen, Charm, Wish, Thunder Wave, Toxic, etc. There's quite a bit you can do with it! Plus: NO x4 ROCK WEAKNESS! A wide offensive movepool also leaves some gimmicky late-game sweeping possibilities with Fake Tears. Use Leftovers or Focus Sash for support sets, and Wise Glasses or Life Orb for sweepers.