It cant fly and it will die...
not much all that happens is cressilia becomes a running Pokemon
The wing span of a Luna moth is 3'' to 5'' inches;3
hummingbird moth
The atlas moth is the largest saturniid moth which originated in Indonesia. The average wing span of the moth is 262 millimeters.
5
You don't get Ho-Oh's lunar wing, you get Cresselia's Lunar wing when you go to the island when the child of the sailor in canalave city falls sick...
After getting the Lunar Wing in Pokemon Diamond, Pearl or Platinum you can take it to Canalave City. In Canalave city is a NPC called Eldritch who is the same one who took you to Fullmoon Island. Giving Eldritch the Lunar Wing will wake his son from his nightmares.
in canalave city, go to sailor eldritch's house post hall of fame. his son is sick and he needs the lunar wing to make him better. he takes you there where you will meet cresselia. it runs off and leaves the lunar wing. sadly you have to relinquish the lunar wing now because the sailor needs it. now cresselia is flying around sinnoh like mesprit, awaiting capture.
you need to go to canalve city talk to the guy who takes you to iron island he will take you to a new island the follow the path to the Pokemon standing there he will fly away after you talk to it it will drop the lunar wing the go back you canalve and go to his house and use the lunar wing on his son in bed
go to canalave city talk to the sailor he'll take you to fullmoon island and there you'll meet cresselia and she'll flee and leave the lunar wing behind
they have diffrent cools for there wing and body
That HawkFrost put the moth's wing beside MudFur's den.