Wikipedia
Issidae is a family of planthoppers described by Spinola in 1839, belonging to the order Hemiptera, suborder Auchenorrhyncha superfamily Fulgoroidea.
Species of this family are present throughout the Northern Hemisphere.
Issidae are small insects generally with a stocky body, as the wings mainly develop in width. Basic body coloration is not striking, usually shows brownish colors. The head has two ocelli. The forewings have strong pronounced ribs. They wrap the abdomen when the insect is at rest. The family includes approximately 1000 species with 215 genera, but the systematics of Issidae remains uncertain, with some of the subfamilies having been recently removed to a separate family, Caliscelidae.
In 2013, scientists described a biologically unique set of mechanical gears in an Issus nymph, though identical structures are known in most planthoppers, and were known for decades before the function of the gears was discovered