Thought to Be Extinct, but Still Alive Today: The Miocene Genus Primascena Klimaszewsi, 1997 (Hemiptera: Psyllidae) in the Light of Two Extant Species from Brazil.

Simple Summary: The psyllid genus Primascena was erected for a fossil species from Dominican amber, P. subita. As the single known specimen of this species is a partly damaged male, the description was quite incomplete. Recently, two undescribed species were discovered in Brazil (Mato Grosso do Sul) that are ascribed to this genus. The extant species allow the description of the previously unknown female and immature, and to complete information on the morphology of the male. A cladistic morphological analysis confirms the position of the genus in the subfamily Aphalaroidinae and supports the monophyly of the fossil and the two extant species. The extant Primascena species develop on plants of the Polygonaceae: Eriogonoideae, an unusual psyllid host, shared by only one other species of the same subfamily. Aphalaroidinae is most species-rich in the neotropics, with nine out of 13 genera being restricted to South America. Fossils can document the morphological diversification through time and date lineages, providing relevant characters are preserved. Primascena Klimaszewsi, 1997 was erected for P. subita Klimaszewsi, 1997 on the basis of a single, partly damaged male from Dominican amber. Originally assigned to Rhinocolidae: Paurocephalinae, the genus was subsequently transferred to Psyllidae: Aphalaroidinae. Recently, two undescribed species resembling the fossil species were discovered in Brazil (Mato Grosso do Sul), allowing a detailed morphological study of adults and immatures. Based on the morphological study, a revised diagnosis of the genus is provided, including the previously unknown female and fifth instar immatures. Primascena subita is redescribed and P. empsycha n. spec. and P. ruprechtiae n. spec. are formally described and illustrated. An identification key is provided for the species of Primascena. A cladistic morphological analysis supports the placement of the two new species in Primascena, and of this genus in the Aphalaroidinae. It is sister to all but Aphalaroida, though with little support. The two Brazilian species develop on Ruprechtia spp. (Polygonaceae: Eriogonoideae), an unusual psyllid host. Immatures of P. ruprechtiae are free-living on the lower leaf face and do not induce galls. [ABSTRACT FROM AUTHOR]