Within Europe, there are still countries or regions where the pseudoscorpion fauna has not been studied at all, or for which only scarce data on pseudoscorpion diversity and distribution have been published (Harvey 2013). This is true for Moldova, a small country located in the eastern part of Europe between Romania and Ukraine. Knowledge about the pseudoscorpion fauna of Moldova is limited, despite progress in research on pseudoscorpions in the eastern and southern part of Europe and the relatively well-known diversity of pseudoscorpions in countries surrounding Moldova (26 species from Ukraine and 74 from Romania) (Harvey 2013, Ćurčić et al. 2014, Gardini 2014, Novák 2014, 2017, Novák & Harvey 2015, Novák & Hörweg 2017, Novák et al. 2019). The first and only records of pseudoscorpions from Moldova were by Schawaller (1989) over 30 years ago, who documented Ephippiochthonius tetrachelatus (Preyssler, 1790), Neobisium sylvaticum (C. L. Koch, 1835), Neobisium validum (L. Koch, 1873) and Chernes hahnii (C. L. Koch, 1839). No research on Moldovan pseudoscorpions was done subsequently (Harvey 2013). The aim of this study is to present new findings of pseudoscorpions and summarize knowledge about the pseudoscorpion fauna of Moldova.

Material and methods

During a field trip in 2019, the third author collected 74 pseudoscorpions at five localities in Moldova (Tab. 1, Fig. 1). Specimens were collected in natural biotopes as well as in biotopes with anthropic intervention, and from three microhabitats: tree bark, a tree hollow and under stones. Pseudoscorpions under tree bark and stones were collected individually using forceps.The sample of wood-mould from a tree hollow was sifted first and the specimens were then collected individually. This collecting method was similar to that described in Bedoya Roqueme & Tizo-Pedroso (2020).

Pseudoscorpions were preserved in 95% ethanol and studied as temporary slide mounts using lactic acid for clearing. After the study, they were first rinsed in tap water and after that returned to 75% ethanol. Some specimens remained in 95% ethanol without mounting. All specimens were examined using a Zeiss Stemi 2000 stereomicroscope. Digital photographs were taken using a Canon EOS 5D Mark II camera attached to a Zeiss Axio Zoom V16 stereomicroscope. Image stacks were produced manually, combined using the Zerene Stacker software, and subsequently edited in Adobe Photo-shop CC. For identification, the keys in Beier (1963a), Christophoryová et al. (2011) and Kolesnikov et al. (2019) were used. The order of families is according to Benavides et al. (2019) while the species in each family are ordered alphabetically. Nomenclature for all species follows Harvey (2013) and Zaragoza (2017). Specimens are deposited in the zoological collection of the Department of Zoology, Comenius University in Bratislava, Slovakia.

A list of Moldavian pseudoscorpions given below is compiled from available published records (Schawaller 1989) and newly collected material. The new records for Moldova are marked with a black circle (•). The following information is provided for each new record: locality code (listed in Tab. 1), habitat, sampling method, sampling date and number of developmental stages. The same information (if available) is provided for published records with the addition of collector name and reference, together with approximate geographic coordinates.

Results

In the present study, 74 specimens from four species, four genera and four families were collected. The species Ephippiochthonius sarmaticus, Chelifer cancroides and Withius hispanus as well as the families Cheliferidae and Withiidae, were recorded for the first time in Moldova (Fig. 2). Moldova represents the second known country for the distribution of E. sarmaticus within Europe. All specimens were collected under tree bark and in a tree hollow, except for two chthoniid specimens which were found under stones. Up to 88% of specimens were collected from plane tree bark. Withius hispanus, with more than 75% of the total specimen number, was the most common species in the whole material. Together with the published data, there are seven pseudoscorpion species belonging to five genera and five families in Moldova.

Tab. 1:

List of the studied localities in Moldova. An asterisk (*) indicates new localities; unmarked locality is from Schawaller (1989). Abbreviations: E – longitude, N – latitude, a.s.l. – above sea level (m)

Fig. 1:

Map of the studied localities in Moldova. White stars indicate new data, black circle indicates published data (Schawaller 1989). For locality codes see Tab. 1. The map was created using the QGIS Geographic Information System

Fig. 2:

Pseudoscorpions collected in Moldova. a. Ephippiochthonius sarmaticus, male; b. Chelifer cancroides, male; c. Chernes hahnii, male; d. Withius hispanus, female. Scale bars: 1 mm

Discussion

The pseudoscorpion fauna of Moldova is mostly represented by species widely distributed across Europe and in several Asian countries. Moreover, the species C. cancroides and E. tetrachelatus could be considered as cosmopolitan (Harvey 2013). Of the three newly recorded species, the discovery of E. sarmaticus is the most interesting because it was recently described from the Krasnodar region in Russia by Kolesnikov et al. (2019) based on three males collected on bunds between drained rice paddies. The two males from Moldova share the main morphological and morphometric characters reported in the original description of E. sarmaticus, i.e. carapace without epistome, with one or two preocular microsetae and two posterior macrosetae (all macrosetae thick); movable cheliceral finger with an isolated subapical tooth (di) and with prominent spinneret; cheliceral palm with two lateral microsetae; palpal chela (length/depth) 0.66/0.11, hand (length) 0.29, movable finger (length) 0.38 mm. With respect to the geographic distribution of this species, there are 750 km between the type locality of E. sarmaticus and the locality of the new find from Moldova. It should be noted that the area in question has been glacialized in the Quaternary past and is currently flat and homogeneous (with the exception of Crimea), with low specific diversity, so nothing prevents the two populations from being conspecific.

Another species newly recorded for Moldova, W. hispanus, lives mainly under the bark and on stumps of different trees (Beier 1963a, 1967, Ducháč 1999, Zaragoza 2007). Occasionally, the species was collected under stones (Dashdamirov 1999), with pitfall traps (Christophoryová et al. 2012) or Malaise traps (Iorio 2018). The present findings of W. hispanus correspond with the previous findings from tree microhabitats.

Chelifer cancroides is most frequently found in human dwellings, outbuildings, bird nests, and tree hollows (Beier 1963a, Legg & Jones 1988, Turienzo et al. 2010, Harvey 2014, Krajčovičová & Christophoryová 2014, Christophoryová et al. 2017). In this study, it was collected under pear tree bark, which is uncommon for this species, as C. cancroides was collected only occasionally under tree bark (e.g. Beier 1963b, von Helversen 1966, Krajčovičová & Christophoryová 2014). The species shows low abundance in tree microhabitats and its occurrence there is probably only accidental (Šťáhlavský 2001, Krajčovičová & Christophoryová 2014).

Based on two newly discovered localities presented in this work, the presence of C. hahnii in Moldova (Schawaller 1989) is confirmed. Chernes hahnii is a typical inhabitant of tree bark and tree hollows, which is also proved by the present study and many findings from other European countries (Beier 1963a, Drogla & Lippold 2004, Krajčovičová & Christophoryová 2014, Christophoryová et al. 2018, Novák et al. 2019).

Our research represents the first contribution to the knowledge of pseudoscorpion diversity in Moldova since the publication by Schawaller (1989), increasing the number of the known species and adding new localities.