Discovering insect species based on photographs only: The case of a nameless species of the genus Scaria (Orthoptera: Tetrigidae)

Abstract
A heated debate on whether a new species should be described without a physical specimen, i.e., by designating a photographed specimen to serve as a holotype, has been ongoing for a long time. Herewith, without nomenclatural actions, a new species of the Batrachidein pygmy grasshoppers belonging to the genus Scaria Bolívar, 1887 is identified from the Andean rainforest in Peru. This species is clearly different from all its congeners by morphology and coloration. Two individuals of this peculiar species are known only from the photographs found on iNaturalist. The species has not been observed since 2008 when the photographs were taken. A short historical overview of the topic is given, illustrating the pros and cons of photograph-based species description. The concepts of names, holotypes, research effort, and conservation are discussed and related to the problem at hand. The current state of the taxonomic community’s beliefs regarding this issue is reflected by the authors’ three unsuccessful attempts to name this new species.