New records of Protura (Entognatha, Arthropoda) from Romania, with an identification key to the Romanian species

Abstract The Romanian Protura were studied based on 175 specimens collected from Romania, along with bibliographic data. The main publication on the Romanian proturans was written by M.A. Ionescu (1951), who described 13 species mainly from soil and forest litter from 15 collecting points. The current paper represents the first study at a national level. Faunal data on Protura were obtained from 22 sites, mostly from forests of the Romanian Carpathians and also from a peri-urban area of Bucharest, which had not been studied before. As a result, the Romanian Protura fauna now consists of 27 known taxa in 6 genera and 4 families. Of the 27 taxa, 15 species are new records for Romanian fauna. An identification key to the Romanian Protura species is provided.


Introduction
Proturans are found world-wide except in the Arctic and Antarctic regions (Szeptycki 2007) and primarily live in soil, leaf litter, mosses, and decaying wood. These minute soil-inhabiting hexapods also can be collected from animal burrows, meadows, and agriculture soils or urban areas.
The aim of this study is to improve the study of this little known taxon in Romania by providing new records and distributional data on proturan species.

Materials and methods
Protura were extracted from samples of leaf litter, soil and mosses in Berlese funnels. The material has been deposited in the Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Kraków (ISEA). Specimens were mounted on slides in Marc Andre medium and were observed and identified with a phase-contrast microscope. In total 175 specimens from 22 sampling sites were examined. In our analysis we also considered the data taken from 17 Romanian collecting sites mentioned in the literature. Species were identified based on a key to European Protura (Nosek 1973) and other papers (Shrubovych et al. 2012, 2014, Szeptycki 1980, 1985, 1986, 1991. The taxonomic system of Protura presented by Szeptycki (2007) was followed in this paper. Species distributions were taken from Szeptycki (2005Szeptycki ( , 2007, Shrubovych (2010) for Ukraine, Galli et al. (2011) for Italy and Blesić and Mitrovski-Bogdanović (2012) for Serbia. All collecting sites are shown in Fig. 1.

Abbreviations
The following abbreviations are used throughout the paper: pi -preimago, mj -maturus junior, LII -larva II, LI -larva I.

Results
Twenty-two species of Protura were identified in this study based on our sampling material and 15 new records for Romanian proturan fauna were established. In total, 27 species belonging to 6 genera and 4 families (Hesperentomidae, Protentomidae, Acerentomidae and Eosentomidae) are now recorded from Romania. Some data about ecology, distribution in Europe and in Romania are given for each species and, where appropriate, remarks are provided. An identification key to the Romanian Protura species follows the species accounts.
Distribution in Romania. This species is known only from Periş forest (Ilfov County) (this study).
Remarks. New record for the Romanian fauna.
Remarks. New record for the Romanian fauna.
Remarks. Probably a new species or an intrapopulation variation. Our species differs from A. confinis (Berlese, 1908) in the absence of setae P3a on tergite VII and in a longer foretarsus (135 µm versus 100 µm in A. confinis).
Remarks. New record for the Romanian fauna. Szeptycki, 1997 Material examined. Site 6, one female, one male. Ecology. Xerophilous species; the species was found in plant debris in meadowsteppes (Shrubovych 2010).

Acerentulus halae
Distribution in Romania. This species was reported only from Adam Peak (this study).
Distribution in Europe. Known only from Ukraine (Szeptycki 2007). Remarks. New record for the Romanian fauna. Ionescu, 1937 Material examined. Site 6, one male. Ecology. Xerophilous species; abundant in soil and litter of forests, meadowsteppes and green patches inside cities squares (Szeptycki 1991, Shrubovych 2010.
Remarks. new record for the Romanian fauna.

Acerentulus sp. cunhai-group
Material examined. Site 20, one female. Remarks. The Romanian specimen belongs to the cunhai-group according to Nosek's criteria (1973). It differs from other members of the group in absence of seta P1a on tergites II-III and possession of this seta on tergites IV-V. This specimen probably represents a new species, but more material is necessary.
Distribution in Romania. Malaia (Olt Valley) (this study). Remarks. New record for the Romanian fauna.
Remarks. These specimens probably represent an undescribed species. Acerentomon cf. quercinum differs from A. quercinum Ionescu 1932 in having foretarsal sensillum a shorter, and maxillary and labial sensilla with a different shape; in our opinion these characters are not sufficient for description of a new species. Molecular analysis could clarify their status. Ionescu, 1951 Material examined. Site 18, 2 females, 4 males, 1 LII, 1 LI.
Remarks. New record for the Romanian fauna.
Distribution in Romania. This species is known only from Valea Largă (Prahova County) (this study).
Distribution in Europe. Poland and Luxembourg (Szeptycki 2007). Remarks. New record for the Romanian fauna.
Remarks. New record for the Romanian fauna. Distribution in Europe. Austria, Luxembourg, Poland, Slovakia and Ukraine (Szeptycki 2007).