Selymbriini Marshall & Moulds

Tribe Selymbriini Marshall & Moulds View in CoL (in Marshall et al. 2018), 2018

Selymbriini Marshall & Moulds View in CoL (in Marshall et al., 2018) 2018: 53.

Type genus. Selymbria Stål 1861: 615 View in CoL .

Remarks. The species of Selymbriini are distinguished from other tribes of Tibicininae by a the supra-antennal plate that almost reaches the eye, the absences of an accessory sound structure, exceedingly long, undivided uncus that is not retractable into the pygofer, the aedeagal basal plate of the male is undulated and is not right-angled distally, and a very short theca that is laterally expanded and ornamented distally ( Marshall et al. 2018). The tribe was erected by Marshall et al. (2018) only for Selymbria , but Prosotettix has been reassigned to the tribe since that time ( Sanborn 2021).

The new species possesses a postclypeus that is rounded in transverse cross-section, the lateral margins of the pronotal collar are moderately ampliated, rounded, and broadly U-shaped, there is no lateral tooth on the pronotal collar, in the fore wing a pterostigma is present, the costa and radius+subcostal vein are close together, the radius anterior 1 vein is closely aligned with the subcostal vein for its length, cubitus anterior 1 is divided so the distal section is longer, the hindwing median and radius posterior veins appear to be unfused at their bases, anal vein 3 is curved at the distal end and well separated from the wing margin, and there is a broad anal lobe, the primary spine on the foreleg femur is erect, hindcoxae lack a large, inner protuberance, the meracanthus is triangular and tapers to a point, male opercula do not meet medially, the male abdominal tergites are convex in cross-section, male abdominal tergites 4–7 are similar in size to tergites 2 and 3, the timbals extend below the wing base, there is an undeveloped pygofer distal shoulder, upper pygofer lobes are present, basal pygofer lobes are well developed, the dorsal beak is part of the chitinized pygofer, there is a large, long, non-retractable uncus, aedeagus curved in a gentle arc, without conjunctival claws and pseudoparameres. All of these structures are characteristic of the Selymbriini within the Tibicininae based on the features provided as representative of the taxon at its formation (Marshal et al. 2018).

However, the new genus represents a species possessing an accessory sound structure, the supra-antennal plate reaches only half the distance to the eye, the eyes are not as wide as the lateral angles of the pronotal collar, the postclypeal transverse ridges have grooves along their entire length, hindwing cubital cell 2 is wider than distal cubital cell 1, the male operculum does not cover the tympanal cavity and completely encapsulates the meracanthus, abdominal epipleurites are not reflexed to the ventral surface, the timbal cavity lacks a turned back rim, the aedeagus does not expand distally, and the distal lobes of the aedeagus are reduced in the only known species of the new genus. The monospecific Prosotettix also possesses a species with the eyes not as wide as the lateral angles of the pronotal collar, distal hindwing cubital cell 2 is wider than distal cubital cell 1, the timbal cavity lacks a turned back rim, and the upper pygofer lobes appear to be absent in the figure provided by Jacobi (1907). This is the first known member of the tribe to possess an accessory sound producing structure. Variable presentation of a stridulatory apparatus in specific species of genera or tribes is a condition found in other cicada tribes (e.g. Boulard 1986; Cole et al. 2023).

The original tribal concept was based on a single genus ( Marshall et al. 2018) but tribal characteristics became more variable with the revision of Selymbria and the addition of 11 new species ( Sanborn 2019; Ruschel & Paladini 2024), the inclusion of Prosotettix ( Sanborn 2021) , and the new genus proposed here. There are several divergent characters in the proposed genus from the original concept of Selymbriini , but a new tribe is not erected. The number of similar characters to Selymbriini possessed by the new genus suggests that a new tribe for the new taxon is not warranted at this time. No other tribe within the Tibicininae is suitable to include the proposed genus.