Hygropetric and litter-inhabiting spiders ( Araneae ) from the Abruzzo Apennines ( Central Italy )

We present the results of a study of spider material extracted by means of Berlese apparatus from wet mosses and by litter sieving in broadleaf woods within several natural reserves of the Abruzzo region (Central Italy). The main aim of the work is to contribute to the knowledge of the spider fauna of the Apennines; currently one of the lesser known in Italy. In total, 520 spiders, belonging to 49 species and 14 families were collected. The most abundant and diverse family was Linyphiidae, with 278 individuals belonging to 22 species. Altogether we provide 28 new records for the Abruzzo region, including two species of Theridiidae, twenty of Linyphiidae, four of Hahniidae and two of Thomisidae. We also present additional unpublished records of several rare, litter-inhabiting species collected by litter sieving in the same area. Data on habitat preferences and details on the Italian distribution of the rarest species are presented.

published records of several rare, litter-inhabiting species collected by litter sieving in the same area, including details on their Italian distribution and habitat preference.

Material and Methods
We performed 50 samplings of wet mosses over an area that encompasses the Gran Sasso and Monti della Laga National Park (27 sites), Abruzzo, Lazio and Molise National Park of (2 sites), Sirente-Ve- lino Regional Park (3 sites), springs of the Pescara river Natural Reserve (1 site), Zompo Lo Schioppo Natural Reserve (1 site), springs of the Vera river Natural Reserve (2 sites), Simbruini Mountains SCI (1 site) and Pantano Zittola SCI (2 sites).The remaining 11 samples were performed in similar habitats close to the natural reserves.Most of the sites (47) are located in Abruzzo, only three of them are located outside the border of the region, in Molise (two sites at Pantano Zittola SCI) and one in Lazio (Alvito, Valle di Rio).Details on sampling sites are listed in Tab. 2. Samplings were done mostly in winter or spring between 1993 and 2002, however most samples were performed in the same seasons in 2003 and 2004.On the basis of the most distinctive features of the habitat, we sorted the sampling sites into two groups: limi- madicolous (13) and petrimadicolous (37).In the case of limimadicolous habitats, mosses develop directly on the soil.They are generally shaded by riparian vegetation and kept humid by spray from small waterfalls.According to Vaillant's definition (VAILLANT 1956) petrimadicolous habitats deve- lops on rocky substrates, with a subtle film ofwater running on the rock surface.
For the limimadicolous habitat we identified: Bryum
Pardosa, Pirata and Xysticus were found in both habitats.By litter sieving in the same area we col- lected 26 more spiders, belonging to 11 species 10 genera and 5 families.
A few comments on the most representative species are drawn below.Nomenclature and family order follows PLATNICK (2008).

Dysderidae
Two females of Parachtes siculus (Fig. 1) have been extracted from wet mosses at petrimadicolous sites.
The identification of females in Dysderidae requires care and experience and in some cases remains doubtful.Two females have been identified thanks to the collecting activities, approximately in the same area, of several males of P siculus (Fig. 2    The Italian endemic Pallidu- phantes conradini was collected by litter sieving in a mixed broadleaf wood.This species, apparently endemic to the Abruzzo Apennine, was previously recorded in three caves in Abruzzo and in mountainous areas of the provinces of L'Aquila, Teramo and Pescara (BriGNOLI 1971(BriGNOLI , 1979)).According to our record, the species seems to also show a general preference for moist epigean habitats.Palliduphantes conradini (Brignoli, 1971): Abruzzo, Valle Castellana (TE), National Park of Gran Sasso and Monti della Laga, litter sieving in mixed broad- leaf wood, 850 m, 42°45'N 13°36'E, 11.VIL2007 leg.Marotta: Id.

Conclusions
The present study highlights the potential of hy- Tab.3: Species list of spiders extracted from wet mosses by means of Berlese apparatus, with reference to sampling sites and number of specimens (males, females and immatures).See Tab. 2 for sampling sites codes.COR: corotype according to ViGNA Taglianti et al. (1 992,1 999) -APR: Appeninic, EUR: European, OLA: Holarctic, PAL: Palaearctic, SEU: S-European, SIE: Sibero-European, WEU: W-European, L: limimadicolous sites, P: petrimadicolous, n: number of samples.* indicates new record for Abruzzo region.Alphanumerical code for Parachtessiculus refers to cryo-collection facility at the Centre de Recursos de Biodiversitat Animal, Universität de Barcelona.Nomenclature and order of families according to Platnick (2008).
Taxa COR
sites were characterized by Barbula sp., Brachythecium sp., Didymodon sp., Hymenostilium sp., Orthothecium rufesceju, Pellia endiviaefolia, Plagiomnium ellipticum, P undulatum, Rhynchostegium megapolitanum, R. mumle and R. riparioides.Cratoneuron commutatum, C. filicinum, Eucladium verticillatum and Brachythecium sp. were present in both habitats.Spiders were extracted from wet mosses, both limimadicolous and petrimadicolous, by means of Berlese apparatus.For sample collection we used jute bags.Furthermore, in order to improve the study and provide additional data on litter-inhabiting spiders, we performed several more samplings by litter sieving in the same area.Details on litter sieving samplings are listed in the text.
petrimadicolous the exception of juveniles, which we identified at genus or family level whenever possible.Material is stored in ethanol 70% in Isaia's collection, at the Dipartimento di Biologia Animale e dell'Uomo, Universita di Torino.Two legs of each Parachtes specimens have been stored at the cryo-collection facility at the CRBA (Centre de Recursos de families and 29 species (Tab. 2 and 3).Since they were earliest instars, 94 spiders (24%) from petrimadicolous sites, were not identifiable, even at family level.Four species {Robertus lividus, , Loc.Macchia da Sole, National Park of Gran Sasso and Monti della Laga, litter sieving under stones or in wood litter.Together with R. lividus, a frequent species in damp situations that was extracted both from petrimadicolous and limimadicolous mosses (see Tab. 2 and 3), both species were recorded for the first time in the Abruzzo, Campli (TE), Campo volanoin mixed broadleaf wood, 800 m, 42°40'N-13°36'E,24.IX.2002 leg.Osella:19 (CRBALB000321), Id (CRBALB000322); Abruzzo, Isola del Gran Sasso (A(2), Loc.Pretara, National Park of Gran Sasso and Monti della Laga, ^F.vernaeI Fig. 3: Distribution of Parachtes species in Italy.Black symbols refer to literature data, transparent symbols to new records.Theridiidae By litter sieving in a mixed broadleaf wood we collected a female of Robertus ungulatus, a Palae- arctic widespread species found preferably in moist habitats Robertus ungulatus Vogelsanger, 1944: Abruzzo, Valle Castellana (TE), National Park of Gran Sasso and Monti della Laga, litter sieving in mixed broadleaf wood, 850 m, 42°45'N 13°38'E 11.VII.2007,leg.Marotta: 1 9 .Linyphiidae Linyphiidae were the most abundant and species-rich spiders, especially in petrimadicolous habi- lected by Berlese apparatus extraction of wet petrimadicolous mosses.The original description of this species (MiLLIDGE 1978) is based on material sampled by Prof PM.Brignoli in Toscana and Lazio, but lacks data on the habitat preference.SimilarlyVAN HELSDINGEN (1982)reported the collection of this species by DI CAPORIACCO(1936,sub M. st/us) in Toscana, without any details on the habitat.Data on litter of moist woods (HEIMER &NENTWIG 1991).