A Parasitic Wasp Unmasked: One Species Is Actually 16 Species

The tiny, iridescent parasitoid wasp is the latest insect shown to be a cryptic complex of genetically distinct species.

The tiny, iridescent Ormyrus labotus always seemed suspicious for a parasitoid wasp. It wasn’t the wasp’s striking beauty — wasps can be conventionally attractive, too — but its life strategy. Parasitoid wasps lay their eggs on or inside other insects and arthropods, and the larvae eat their way out when they hatch. Each parasitoid wasp species tends to prefer one or a few hosts. But Ormyrus labotus had been observed laying its eggs in more than 65 different species of insects — far more than one or a few.

Ormyrus labotus parasitizes gall wasps, which lay their eggs on plants and induce them to form protective, swollen structures called galls around the larvae (a parasite, in a parasite!). When galls from different wasp species form, they take on a variety of sizes and shapes. Some are much tougher than others, some have unusual defensive strategies. There are galls that are chambered, secrete nectar or bristle with fibers. Parasitoid wasps often have specialized adaptations that allow them to broach certain kinds of gall.

But Ormyrus labotus, it seemed, had no problem penetrating an assortment of galls: lime-green and polka-dot round galls, spiky yellow galls on the blade of a leaf and stubbly galls on a twig. “It seemed weird that one species could be sort of effectively attacking all of these different galls,” said Sofia Sheikh, a doctoral student at the University of Chicago who did research on the wasps when she was at the University of Iowa.