Anastasia Ashley Naked and Attacked by Sandflies!

Anastasia Ashley lasted 6 of 21 days in the jungle ... but called it quits after a nasty ambush by a swarm of sandflies ... while she was naked.

The pro-surfer/bikini model is currently in Belize after competing on season 7 of Discovery's, "Naked and Afraid." The new season kicks off Sunday on Discovery, but Anastasia's episode will be airing later.

She described the nighttime ambush that cut her stay short. Don't worry, the bites are healing and Anastasia expects to be bikini-ready ASAP.