One of the staple events from Gold & Silver makes a return in HeartGold & SoulSilver; The Bug Catching Contest. The Bug Catching Contest is a special contest that takes place on Tuesdays, Thursdays & Saturdays and has you sent out into the National Park to capture Bug Pokémon.
You get sent in with 20 Competition Balls and you have to capture the best Pokémon. However, unlike the Safari Zone, you get to choose 1 of your Pokémon to go in with and you have to battle the Pokémon with that Pokémon.
After you have defeated the Elite Four and obtained the National Pokédex, more Pokémon are added to be captured such as Wurmple.