You know that one butterfly?
Well, they are starting to die off, and it's not something as simple as “they need more food.” There are multiple things causing this. One is that they are losing their habitats. Two is that their food supply is running out. It is very unfortunate considering how iconic this particular butterfly is.
Here is a link with way more info than I can type.Source : http://monarchwatch.org/bring-back-the-monarchs/campaign/the-details/