Romaleosyrphus villosus

The name Romaleosyrphus villosus was published by Jacques-Marie-Frangile Bigot in 1882, in reference to a species of hoverfly from Mexico.

Unfortunately, its name has been confused with the name of a related species described from the United States, which was originally described as Merapioidus villosus, published in 1879 by the same author. These two species are now both placed in the same genus, Criorhina, and only the older of the two names (the one from 1879) can remain as Criorhina villosa, so the 1882 name will need to be replaced, and as of 2023 this has not yet occurred, so the species is effectively nameless, other than its original (but nomenclaturally invalid) name.