Went to donate my final bug to Blathers, and...

[michealsmells]

I did something similar! I didn't manage to catch a horned hercules before they went outta season

 

[Skandranon]

I messed up to, found out when i donated the cicada shell I hadnt donated a flea, was so relieved when I checked my inventory and found one. I know the yellows are currently on my second island, looks like someone else helped, if not let me know.

 

[Xara]

ah,, that’s super frustrating but i’m glad that you were able to catch one! i’m sure your son will be super excited to donate it tomorrow.

 

[Purities]

I have the yellow butterfly spawning on my island currently, if you'd like, shoot me a PM and hopefully we can catch eachother be happy to let you come and catch one I'm in the Southern Hemisphere and see them very often

If you already found help, no worries just leaving this here incase it falls through