Chain Breeding
Using chain breeding, you can teach Pokemon egg moves from other Pokemon's egg moves. In the case of Ledyba, you need to breed it with a Volbeat that knows Dizzy Punch as a egg move. To get a Volbeat with Dizzy Punch, you need to breed it with a Spinda or Buneary/Loppuny who knows Dizzy Punch, and they learn it from level up.
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