There's a reason Hawaii's micromoths have long been challenging to find and study—some can be roughly the size of your eyelash.

But National Geographic explorer Chris A. Johns is up to the challenge. He's discovered, for instance, that these moths' caterpillars dine exclusively on a few Hawaiian plant species. These voracious insects burrow within leaves and "mine" their way out.

While the 40-plus known species of Philodoria micromoths native to Hawaii are closely related, the plants they eat—many of which are highly endangered—are spread across 12 very different families. (Related: "The Race to Save the World's Rarest Plants")

“It’s not typical that you find an organism where each species is so specific but all of the relatives as