Songhaicinae, Sánchez-García & Engel, 2016

Wynne, J. Judson, 2017, Disparrhopalites naasaveqw n. sp. from caves at Wupatki National Monument, Arizona, synonymy of Dietersminthurus Palacios-Vargas, Cuéllar & Vázquez, 1998 with Disparrhopalites Stach, 1956 and composition of Songhaicinae (Collembola: Sminthuridae), Zootaxa 4319 (1), pp. 77-90 : 80-81

Subfamily Songhaicinae

Songhaicinae Sánchez-García & Engel, 2016: 12.

Type genus. Songhaica Lasebikan, Betsch & Dallai, 1980

Updated diagnosis of Songhaicinae . Small species less than 1 mm long. Eyes present, rarely absent. Ant. IV with 10‒26 subsegments. Tibiotarsus of all legs with six or fewer setae in apical whorl. Unguis usually with prominent cavity and tunica, sometimes free apically as filament; if cavity absent, filament present. Unguiculus typically truncated along inner edge, without or with very short terminal filament. Tenent hairs acuminate. Neosminthuroid setae present or absent. Anterior surface of dens with 5‒13 setae. Mucro without subapical notch. Subanal appendage tapering, smooth or with a few minute serrations near tip, pointing posteriorly.

Genera and species. See Table 1 for names and authorities.

Relationships within Songhaicinae . Recently, Songhaica was transferred to its own subfamily (Sánchez- García & Engel 2016) with the following diagnostic characteristics: “three pairs of sminthuroid [= neosminthuroid] setae, a few anterior setae on the dens, and the mucro lacking a subapical incision.” Only this last mucronal character fits all of the species listed in this paper; neosminthuroid setae are present only in Songhaica and most species have more than five anterior dental setae. Songhaica spp. have a cavity in the unguis ( Bretfeld 2005), which corresponds to the other 10 species of this group, except for D. tergestinus . However, the presence of a welldeveloped tunica occurs in all species of the group except Songhaica spp. In addition, all those species that have the apex of the tibiotarsus adequately illustrated have only six setae in the apical whorl. The combination of these characters (six apical tibiotarsal setae, ungual cavity, well-developed tunica) serves as a rationale to unite the 13 species in the same subfamily. The significance of neosminthuroid setae as a subfamily characteristic is difficult to estimate since the sminthurid subfamily Sphyrothecinae also possesses them ( Bretfeld 1999), as does Sminthurinus Borner, 1901 (Katiannidae) ( Bretfeld 1999) and Neelidae ( Richards 1968) . Therefore, the presence of no more than six setae in the apical tibiotarsal whorl and the combination of a filamentous tunica and/or ungual cavity serve better to characterise this subfamily within Sminthuridae .

Relationships with other sminthurid subfamilies. Betsch (1980) proposed two subfamilies for Sminthuridae ( Sphyrothecinae and Sminthurinae ), an arrangement followed by Bretfeld (1999). Songhaica was considered by Bretfeld (1999) to be intermediate in position between Sphyrothecinae and Sminthurinae , but primarily allied with Sminthurinae . Sánchez-García & Engel (2016) established Songhaicinae with a very brief diagnosis and without direct comparison to the other subfamilies. Sphyrothecinae and Songhaicinae are similar in usually having fewer than 20 subsegments in Abd. IV. However, species of Sphyrothecinae possess neosminthuroid setae and modified setae on the abdomen, lack a spine-like tunica and cavity on the unguis, and have tapering unguiculi with short or long terminal filaments. All songhaicine taxa except Songhaica spp. lack neosminthuroid setae, which are considered a diagnostic feature of Sphyrothecinae (Betsch 1980) . Songhaicinae and Sminthurinae have overlapping ranges for the number of anterior dental setae (5-13, 9‒15, respectively), but shapes of the unguis and unguiculus are distinctly different.

All of the species included here in Songhaicinae that are sufficiently illustrated have six or fewer setae in the apical whorl of the tibiotarsus. This character has not typically been included in sminthurid descriptions, but in those where they are illustrated (e.g., Betsch 1980; Delamare Deboutteville & Massoud 1964; Nayrolles 1995; Yosii 1959) tibiotarsi of Sminthurinae and Sphyrothecinae have more than six apical setae.