One day last week I was folding the laundry, which had been hanging out on the line all day. As I shook a t-shirt to fold it, up flew a tiny moth. When it landed again, I noticed that it looked odd. It sat with wings wrapped around it, a bit like a grass moth. But it held its spiky back legs high in the air, unlike any moth I’d seen. I took a couple of photos, none of which came out great—the iPhone just wasn’t made for macrophotography.
Still, even with a grainy photo, I was able to identify the moth to the genus Stathmopoda.
That’s where it started to get weird.
Everyone knows that butterflies and moths start off their lives as caterpillars, and that caterpillars eat plants, right?
Not so, in the genus Stathmopoda. Instead of munching leaves, the caterpillars of Stathmopoda eat other insects.
Yes, they’re carnivorous caterpillars.
They prey primarily on scale insects, so some species are actually used as biological control agents to help control these pests.
They are not the only carnivorous caterpillars. Though carnivory is rare among butterflies and moths, it has evolved separately several times in at least eight different lineages. Most carnivorous caterpillars eat small, slow-moving or sedentary insects, as you might expect from an animal that is neither speedy nor particularly formidable itself. As far as we know, there is only one moth that is carnivorous as an adult—the ‘vampire moth,’ Calyptra eustrigata, which feeds on the blood of ungulates.
I’m quite happy that this little Stathmopoda is carnivorous. Our currants suffered a bad case of scale insects this summer, so I hope there are lots more Stathmopoda out there. Here’s wishing it great reproductive success in the garden!