Taxonomic revision of 14 south-western European species of Isotomurus (Collembola, Isotomidae), with description of four new species and the designation of the neotype for I-palustris
A. Carapelli et al., Taxonomic revision of 14 south-western European species of Isotomurus (Collembola, Isotomidae), with description of four new species and the designation of the neotype for I-palustris, ZOOL SCR, 30(2), 2001, pp. 115-143
A detailed study of morphological characters in populations of the collembo
lan genus Isotomurus from southern Europe is presented. Isotomurus is a cos
mopolitan genus in which species diagnosis primarily relies on pigmentation
patterns and chaetotaxy. Correct diagnosis is often complicated by the hig
h variability of these characters. This has created confusion in the system
atics of the genus and has led to descriptions of several varieties, colour
forms and subspecies, the taxonomic value of which needs revision. Complet
e screening of pigmentation patterns and the study of sensorial chaetotaxy
in specimens collected in 37 localities across south-western France, Italy
and Switzerland have enabled 14 species to be distinguished; one taxon is e
levated to the rank of species (Isotomurus prasinus) and four new species a
re described: I. hadriaticus, I. aetnensis, I. gallicus and I. pseudopalust
ris. The neotype for I. palustris is designated in order to clarify the tax
onomic status and the type locality for this species whose topotypic materi
al is lost. A redescription of previously known species on the basis of the
newly introduced characters is also presented, together with a key to the
south-western European species of Isotomurus. Following this study, the two
species I. indipendente and I. italicus came to be junior synonyms of I. p
alustris and I. fucicolus, respectively. A cladistic analysis of 14 morphol
ogical characters provides a phylogenetic reconstruction which is largely c
oncordant with previous taxonomic works.