Taxonomy of the Proisotoma complex. Redefinition of genera and description of new species of Scutisotoma and Weberacantha(Collembola, Isotomidae)

Abstract

The paper provides new information on morphological characters which are useful in generic diagnostics of the Proisotoma complex of Isotomidae. Based on this information, a number of known species are excluded from the redefined Proisotoma s. str. and moved to the genus Scutisotoma Bagnall, 1949, which is again given generic status. The following genera are given more precise definitions: Subisotoma Stach, 1947, Ballistura Börner, 1906, Proisotoma Börner, 1901 and Weberacantha Christiansen, 1951. A new genus, Strenzketoma, is erected for the species “Proisotoma” buddenbrocki Strenzke. Scutisotoma titusi (Folsom), S. muriphila (Grinbergs), and S. ladaki (Denis) are redescribed. Fourteen new species of the genus Scutisotoma (S. acorrelata sp.n., S. baica sp.n., S. dodecocellata sp.n., S. indigirka sp.n., S. karadagi sp.n., S. kolymica sp.n., S. longisensilla sp.n., S. matalini sp.n., S. millimetrica sp.n., S. montana sp.n., S. nicksmeti sp.n., S. schisti sp.n., S. stachanoremi sp.n., S. tenuidentifera sp.n.) and two new species of Weberacantha (W. echinodermata sp.n., W. magnomucrella sp.n.) are described. Types of S. ananevae (Babenko & Bulavintsev), S. armeriae (Fjellberg), S. christianseni (Stach), S. oirota (Vilkamaa), S. stepposa (Martynova), S. tianshanica (Martynova), and S. tolerans (Babenko) have been studied. Keys to genera and to the known Holarctic species of Scutisotoma Bagnall and Weberacantha Christiansen are given.

Bellisotoma, a new genus of Isotomidae from North America (Hexapoda, Collembola)

“…Bellisotoma joycei keys out to Ballistura in Potapov (2001), but the two genera are clearly distinguished by maxillary palp structure, sensillar and microsensillar formulae, absence of tibiotarsal seta B4/5 and dens sculpturing. Additional differences between the new genus and other genera in the Proisotoma complex (Potapov 2001, Fjellberg 2007, Potapov et al 2006, 2009) are listed in Table 1. One other North American species, Ballistura ewingi (see below), belongs in the new genus.…”

Las especies neotropicales de Proisotoma (Collembola: Isotomidae), con descripción de dos especies nuevas cavernícolas de América

“…Proisotoma Börner, 1901 Diagnosis. Las especies tradicionalmente incluidas en Proisotoma pertenecen a varias líneas evolutivas diferentes y actualmente son objeto de estudio por Potapov et al (2006). Proisotoma s. str.…”

“…P. minuta y una especie inédita fueron citadas recientemente por Cutz-Pool et al (2007). Según los criterios de Potapov et al (2006), algunas de estas especies pertenecen a géneros diferentes: Folsomides Stach, 1922, Ballistura Börner, 1906, Scutisotoma Bagnall, 1949 y otros más, aún por defi nir (véase discusión al fi nal del trabajo).…”

Three new species of Oligaphorurini (Collembola: Onychiuridae) without anal spinesfrom European Part of Russia

“…First they were formally identified as the members of the genus Archaphorura Bagnall, 1949. So far this small taxon was readily identified by the absence of anal spines and its taxonomical position remained the least disputable [Weiner, 1996;Pomorski, 1998;]. One of the new species under study, however, shared several significant characters with Micraphorura Bagnall, 1949, while the other two taxonomy of family Isotomidae anal spines get recently less value in the definitions of genera [Fjellberg & Potapov, 1998;Potapov et al, 2006Potapov et al, , 2010.…”