On the island of Raivavae, one of the Austral Islands in the middle of the Pacific Ocean, buried deep beneath the surface of a swamp in mud accumulated at the foot of a stream for thousands of years, scientists have found all that remains of a unique new species of Black Fly (Simuliidae): larval head cases left behind when the flies molted into pupae. These subfossils, not yet hard and mineralized like conventional fossils yet still preserved in near-perfect condition by the mud, not only raise the question of how a tiny little fly found its way to an island in the middle of nowhere, but also provide the only evidence of a murder mystery 2 million years in the making.
The missing species on Raivavae is Simulium Inseliellum raivavaense, recently described by Douglas Craig of the University of Alberta and Nick Porch of Deakin University in Australia, from material collected in 2010. Despite the subfossil larval head capsules being the only “specimens”, Craig & Porch were able to determine S. I. raivavaense was a new species based on the shape, position, and number of teeth on the hypostoma, essentially the lower lip of a black fly larva’s mouth.
