I was in our edible patch this afternoon when a flicker of crimson silently swooped past me. I was surprised and caught off guard to see a butterfly circling. At first glance I wondered if it was a Gulf Fritillary. However, it didn’t match my mental image of one, and it is winter.
It landed near the fence, and I went over to investigate. At one point, it sensed me. The frail creature played dead and closed its wings to reveal incredible camouflage! It looked just like the fallen leaves around it. I snapped some pictures and took some video to try to identify it before I helped it get airborne again. A quick google search revealed I had encountered a winter form of Goatweed Leafwing, a name that sounds more like random words shouted in charades than a gorgeous and fascinating butterfly. The summer form’s color is a bit more drab orange.
Amazing, eh?! Look at how the Goatweed Leafwing looks just like the oak leaves around it. Its pinnate and reticulate venation pattern game is strong.
Eventually, it landed in an eastern red cedar. And, I leaned over a barbed wire fence and held the camera high to try to get some good detail of the Goatweed Leafwing.
The name describes both its plant host and plant mimicry. Goatweed (aka Croton capitatum) is the larval food source along with Texas croton (Croton texensis) and prairie tea (Croton monanthogynus). That’s it for plant hosts, which made me ponder planting some weedy Croton in my yard. Only for a second, though; it is everywhere along the roadsides. The leafwing part alludes to the underside of the wing resembling fallen foliage.
I spent part of the rest of the afternoon thinking about how in the world does an insect that’s a host on one herbaceous plant evolve to look like a dead tree leaf? Research supports that it occurred step by step in Kallima, another butterfly that resembles a dead leaf. (Here’s the official paper or the National Geographic CliffsNotes version.) That’s likely the case with my new friend. These leafwing mimics evolve a bit to look like a leaf, which decreases the chance they’ll get eaten. And, over time, these changes accumulate. A line that looks like a vein here, a reticulate vein pattern there, and less and less adults get eaten.
Discovering this species today filled me with wonder and helped me better understand the ecological history of this area. It was a fun find for a gray day.