Naruto Shippuden Episode 287 English Sub

"One Worth Betting On"
As she listens on to the events of A and his followers ambushed by a ninja group known as the Nokizaru, Tsunade realizes the nature of the insect as a bomb with another inside A. After explaining this and having A make a promise to her, Tsunade catches and destroys a bug which had been hovering near A for some time — unbeknownst to them that the Nokizaru had been using it