Pokémon : S3 | E12 – The Whistle Stop

Team Rocket watches as Ash and his friends travel approach the bridge they are on, and plot to drop them into a cage under the bridge and lock them in it. However, the bridge suddenly collapses prematurely, and Team Rocket falls into the river below. The gang arrives at the bridge and notices the gap in the middle, not knowing that Team Rocket caused it. They think of how to get across, with the nearest bridge being ten miles away. They then notice a woman traveling aboard a Ledyba and ask her help across the river. She introduces herself as Arielle and says that she can fly them across using her Ledyba, which she controls with a Whistle. She takes them across, one at a time.

Afterwards, Arielle tells the group about her job, which involves picking apples using her Ledyba in order to pollinate them. Intrigued, Ash sends out his Heracross to help the Ledyba, though it decides to suck maple out of the tree instead. Team Rocket spies on the gang and realize that Arielle's control over the Ledyba would be a good present for the boss. They manage to steal the whistle after pretending to be TV hosts. Team Rocket recites their motto and takes off in their Meowth balloon. In the air, Jessie blows the whistle, but the Ledyba do not obey her because she hasn't trained with them. Jessie sends out Lickitung, which uses Supersonic, leaving them confused and unable to listen to Arielle. Pikachu, unaffected by the attack, uses Thunderbolt on the balloon, sending Team Rocket blasting off. However, the Ledyba follow Team Rocket, since Jessie is still in possession of the whistle.
(Source: Bulbapedia)