Last summer, while working on my square meter photography project, I made a lot of discoveries, including quite a few species I’d never seen before. Only one made me briefly question my understanding of life and death.
I was peering into my little square meter plot one morning in August when I spotted something light-colored sitting motionless on top of a dewy leaf of grass. It was small enough that I had to train my macro lens on it to get a better look. What I saw through the lens appeared to be the exoskeleton of a small fly. It was pale and appeared to be just an empty shell.
Now, tt’s been long enough ago that I don’t remember exactly WHY I thought it might be the exoskeleton of a fly; it seems pretty far fetched in hindsight. There are two ways I could have been right. First, the “fly” could have been dead. Maybe it was killed and eaten by a spider or assassin bug, both of which feed by liquefying and then sucking the insides out of their prey. I might have been looking at a discarded husk of something a creature like that had eaten. However, the fact that the insect was perched upright on a piece of grass makes that seem pretty unlikely.
The second possibility is that the “fly” had molted out of its previous exoskeleton after outgrowing it. This happens with the nymphs of various species that go through incomplete metamorphosis. However, flies don’t go through incomplete metamorphosis – they transform from larva to adult via a pupal stage. Because of that, there’s no way I could have been looking at the shed skin of a fly. I’m such a chucklehead.
Nevertheless, at that particular moment, my brain was telling me that I was looking through a macro lens at a fly’s exoskeleton. Even if it wasn’t an empty fly, it sure looked like the dried and hollowed out body of SOMETHING. Picture my shocked face, then, when that dead empty shell started to slowly walk up the leaf…
Now, I want you to study the above photo. That’s a dead creature, right? Of course it is. Except that it wasn’t. I’m not the brightest bulb, but even I know that zombie flies, or any kind of zombie insect, aren’t a real thing. (Don’t you dare steal my movie idea, though – it’s MINE!) Clearly, I was looking at some kind of living creature. I just couldn’t imagine what it might be.
Later, I discovered that my “zombie fly” was really a derbid plant hopper. According to bugguide.com, “Derbids generally can be recognized by having the row of spines on the second hind tarsal segment and having the apical segment of the beak short.” Oh. Well, now I feel silly… I completely missed that row of spines on the second hind tarsal segment, and I didn’t even think to look for the apical segment of the beak!
Derbid planthoppers are a very diverse group of insects with almost 1,700 species found around the world. According to a couple online sources, derbid nymphs feed on fungi. Adults feed on plants, and at least some are host-specific, meaning that they feed only on a single plant species or group of species. I would love to know if the derbid I photographed was a specialist feeder on one of the plants in my little plot. I would also love to know if the derbids I found in the plot in September and October were actually the same individual as the one from August. It seems unlikely – but probably more likely than a zombie fly.
The Prairie Ecologist 