Since it’s Darwin Day, I’ve featured only evolution-related issues, and let’s finish with some amazing pictures by photographer and entomologist Gil Wizen, taken from his eponymous website (with permission; note that he also has a Twitter page and a Facebook page). (N.b.: the photos are used with permission and cannot be reproduced further.)
In a post called “Petrophilia“, Wizen shows a moth in that genus, trapped in Belize, with some weird markings on its hindwings (captions are from Wizen):
Why are they there? We’re not sure, but one clue is how the moth rests:
Many moths rest with their hindwings concealed by the forewings, however these moths, belonging to genus Petrophila, had a unique body posture at rest, exposing only the dotted part of their hindwings. This pattern looked very familiar to me, but I could not pinpoint from where exactly. Then a few nights later one of these moths decided to rest pointing sideways with its head rather than upwards like most moths. And it finally hit me: this moth has an image of a jumping spider on its wings looking straight at you. The mimicry is so convincing that the moth wings even have hair-like scales where supposedly the spider’s head is.
Here’s the moth and its putative “model” (remember, this is a case of Batesian mimicry, in which a palatable mimic apes an unpleasant or dangerous model). Wizen is careful to hedge his explanation:
What I mean to say is that the color pattern on the wings of Petrophila species reminds me of a salticid spider, and perhaps it works the same for other animals as well. There is also a behavioral display that makes the mimicry even more deceiving: the moth moves its wings to mimic the movements of a jumping spider. In search for a second opinion, I turned to someone who breathes and sleeps jumping spiders. Thomas Shahan, who fortunately was around for BugShot, confirmed my suspicion and even came up with an ID for a possible model spider: a female Thiodina sp. And so we went on to find a jumping spider that looked like the one shown on the moths’ wings. In any case, to my untrained eyes it seems that this pattern is common in several moth genera, and in other insects as well.
You can see another moth with a similar pattern at his site, as well as a caddisfly with a salticid-like pattern.