Of the many collectibles to find in The Legend of Zelda: Skyward Sword HD, Gratitude Crystals are among the most valuable. You'll receive these gems after helping the residents of Skyloft with their various problems, and you can trade them to Batreaux for special rewards like bigger wallets and pieces of heart, so you'll want to collect as many Gratitude Crystals as you can while adventuring around the skies.
One of the final Gratitude Crystal side quests you can undertake involves the merchant Beedle and his precious missing beetle. Here's what you need to do to recover the insect and earn more Gratitude Crystals. For more tips, be sure to check out our Skyward Sword HD guides roundup, which will also help you find every heart piece and Goddess Cube location in the game. Be sure to also read our Zelda: Skyward Sword HD review for our full thoughts on the game.
Prerequisites: Must defeat Bilocyte
Once Strich opens up Bug Rock in the thunderhead, this will open the final Gratitude Crystal-related task. Head for Beedle's airshop and sleep 'til night. Wake up, and talk to Beedle on his island. He needs to recover his precious Horned Colossus Beetle. Go back to sleep and awake in the morning. Go to Strich's island in the thunderhead. He will confess to taking Beedle's property unknowingly but will only return it to Link if you can beat his expert-level bug catching challenge. Catch the required number of bugs in less than three minutes, and he will return the cage to you. Sleep until nighttime in Beedle's shop once again and return the cage to him for your reward.
For details on the rest, be sure to read our Gratitude Crystal quest roundup, including walkthroughs for each one, locations for individual Gratitude Crystals, and the rewards you can get from exchanging them.