3:10 PM PT -- 50 Cent threw another jab at Busta Rhyme's barber and given his latest edit, it's clear he's strumming up attention for his upcoming Las Vegas residency!!!

That's how you keep the people going!!!

50 Cent woke up today and couldn't bite his tongue any longer after seeing Busta Rhyme's spray-painted hairdo on his timeline for the umpteenth time -- but probably didn't count on Bus-A-Bus having a few scalping swipes of his own!!!

On Tuesday, 50 put the spotlight on Busta's suspicious hairpiece and called out his right-hand man Spliff Starr for allowing that dipped ice cream cone on his head ... it's a dirty job but somebody's gotta do it!!!

The G-Unit legend also gave Fat Joe's hair dye Rewind It 10 some backhanded promo -- ordering Joe, DJ Khaled and Tyson Beckford to get Busta a box pronto so he could knock off the bulletproof wig!!!

But, lo and behold, Busta's been playing the dozens before 50 made it out of Southside, and swung back by digging up that time 50 experimented with a Jheri-curl do back in 2011.

50 was slated to portray a Dominican in a film while growing his hair out ... Busta is under the impression he was simply stinking up the place for everyone around him!!!

The public roasting is all fun and games ... 50 and Busta have been friends for years but sometimes, you just gotta keep it real.