Centromerus cf. paradoxus ( Simon, 1884 )

Ballarin, Francesco & Pantini, Paolo, 2020, Three new species and new records of the genus Centromerus (Araneae, Linyphiidae) from Italy, European Journal of Taxonomy 660 (660), pp. 1-23 : 15-17

Centromerus cf. paradoxus ( Simon, 1884)

Figs 7 A–B, 8, 10

For a complete list of references, see WSC (2020).

Material examined

ITALY – Liguria Region • 1 ♀; La Spezia, Portovenere , Isola Palmaria ; 170 m a.s.l.; 24–28 Apr. 2003; S. Ciocca leg.; MSNB. – Umbria Region • 2 ♂♂; Perugia, Nocera Umbra, Colle Aprico, Pendici Monte Pennino ; 700 m a.s.l.; Jan.–Jun. 1992; pitfall traps; P. Pantini and M. Valle leg.; MSNB • 5 ♂♂, 2 ♀♀; Perugia, San Giustino , near Lama village; 400 m a.s.l.; Jan.–Jun. 1992; pitfall traps; P. Pantini and M. Valle leg.; MSNB • 1 ♂, 1 ♀; Perugia, Sigillo , near the village; 500–550 m a.s.l.; Jan.–Jun. 1991; pitfall traps; P. Pantini and M. Valle leg.; MSNB • 1 ♂, 1 ♀; same locality as for preceding; Jun.–Dec. 1991; P. Pantini and M. Valle leg.; MSNB. – Lazio Region • 1 ♂; Roma, Canale Monterano , Regional Natural Reserve of Monterano , Diosilla ; 42.1313° N, 12.0902° E; 255 m a.s.l.; 15 Jan.–15 Feb. 2008; deciduous forest with black alder ( Alnus glutinosa ) and hornbeam ( Carpinus betulus ); pitfall traps; V. Rizzo and A. Vigna leg.; MSNV • 1 ♂; same locality as for preceding; 15 Feb.–14 Mar. 2008; V. Rizzo and A. Vigna leg.; MSNV. – Basilicata Region • 2 ♂♂; Potenza, Viggianello ; 550 m a.s.l.; Jun. 1990 – Jun. 1991; pitfall traps; G. Buttarelli, E. Ghilardi, P. Pantini and M. Valle leg.; MSNB.

Other material ( Centromerus paradoxus ( Simon, 1884))

SPAIN – Tarragona Province • 1 ♂, 1 ♀; Ulldecona, Avenc de les Canals ; 28 May 2014; EGA-MZB leg.; MCNB • 1 ♀; Torre Español , Mina Horts nº 1; 24 Jun. 1998; F. Fadrique leg.; MCNB • 1 ♀; Vallclara (Conca de Barberà), Cv. del Mas de la Llana ; 11 Mar. 2012; R.S. and J.P. leg.; MCNB . – Castellón Province • 3 ♀♀; Xert, Av. Comanegra ; 9 Apr. 1993; O. Escolà leg.; MCNB • 1 ♀; Tirig (Alt Maestrat), Cv. de Mas Abad ; 15 Dec. 1996; F. Fadrique leg.; MCNB .

Comparative material

SERBIA • ♂, holotype of C. acutidentatus Deltshev, 2002 , 1 ♀, paratype; vili. Selacka near Minicevo, Monastery Cave I, at the entrance ; 15 Nov. 1997; in leaf litter; RND, OSK, VTT, SBĆ and NBĆ leg.; MHNG .

Distribution

Western Mediterranean. In Italy widespread along the entire Apennine mountain chain. See Fig. 10 .

Remarks

Records of C. paradoxus have long been considered doubtful for the Italian fauna since Brignoli (1972), thus being omitted in the recent Catalog of the Italian Spiders by Pantini & Isaia (2019). New records from Italy herein reported confirm the presence of a member of the paradoxus species group in the Italian peninsula. The paradoxus species group currently covers a wide distributional area across Europe, with species recorded in the Western Mediterranean ( C. paradoxus ( Simon, 1884)) , Balearic Islands ( C. ponsi Lissner, 2016 ), Carpathian Mountains ( C. gentilis Dumitrescu & Georgescu, 1980 ) and the Balkans ( C. acutidentatus Deltshev, 2002 and C. obenbergeri Kratochvil & Miller, 1938 ) ( Nentwig et al. 2020). However, among such species, only minor differences in the diagnostic characters of palp and epigyne can be observed, making their morphological separation tricky. Such interspecific similarities suggest the presence of cryptic species or potential misidentification of one or a few species with a wide distribution and high local intraspecific variability. In light of these facts, a general revision of this species group, possibly including both morphological and molecular analysis, seems necessary to confirm the validity of the current taxonomy.

Our specimens from Italy show few morphological differences with congeners such as C. paradoxus and C. acutidentatus , making a specific diagnosis difficult. In our opinion, the differences observed are insufficient to establish a new species. In order to avoid further problems in the already confusing taxonomy of this group, we temporarily attribute the Italian specimens to C. cf. paradoxus , the species which, geographically, is most likely to be present in Italy. Further studies, involving a precise morphological and molecular comparison of all the species of this group, will allow a better identification of the Italian samples.

Figures

Fig. 7. A–B. Centromerus cf. paradoxus (Simon, 1884), from Canale Monterano. A. Male palp, retrolateral view. B. Ditto, prolateral view. C–D. Centromerus desmeti Bosmans, 1986, from Serra Juncari. C. Male palp, retrolateral view. D. Ditto, prolateral view.

Fig. 10. Distribution in the Italian peninsula of the species C. tongiorgii sp. nov. (= red dots); C. hanseni sp. nov. (= azuretriangles); C. gatoi sp. nov. (= yellow diamonds); C. cf. paradoxus (Simon, 1884) (= green pentagons); C. desmetiBosmans, 1986 (= violetstar); C. succinus (Simon, 1884) (= dark bluesquares).