Dysdera balearica Thorell, 1873

Hernández-Corral, Jesús, 2017, The spider family Dysderidae in the Balearic Islands, Zootaxa 4329 (4), pp. 375-391 : 380-382

Dysdera balearica Thorell, 1873

Figs 17–24 , 27–28

Dysdera balearica Thorell, 1873: 581 (descr. ♂); Simon 1914: 112.

Dysdera mordax L. Koch, 1882: 640 , pl. 20, fig. 20 (descr. ♂); Bosmans & Van Keer, 2012: 6 , fig. 1. New synonymy.

Type material. Neotype ♂, by present designation from Spain, Majorca , Pollença, Cala Boquer, 12.III.1971, D. J. Clark leg.; deposited in BMNH .

Holotype ♂ (with both palps missing) of Dysdera mordax from Spain, Majorca, Palma de Mallorca , Schaufuss leg., MNB 7905; examined.

Diagnosis. The species can be confused with D. crocata because it has the same colour and size, but differs clearly because of the more spinous metatarsi IV, the much smaller posterior apophysis of the male bulbus, the tapering and terminally pointed distal part of the bulbus (with parallel margins and terminally obtuse in D. crocata ), the less wide spermathecae (2–3 times as wide as it is long in D. balearica , up to 5 times in D. crocata ), and the oblique lateral margin of the dorsal arch (rounded in D. crocata ).

Description. Measurements: Male: Total length 10.4; prosoma 2.08 long, 1.63 wide; head 2.03 wide; chelicerae 0.88 long. Female (n=6): Total length 10.2–13.0; prosoma 3.44–4.28 long, 3.01–3.28 wide; head 1.81– 2.01 wide.

Eyes: All eyes equal, on common, small tubercle; AM separated by 2/3 their diameter, from anterior margin by their diameter; PM touching, separated from PL by 1/3 diameter.

Chelicerae with 3 teeth, distal tooth well separated from the two basal teeth; cheliceral fang much shorter than basal part (ratio 0.7).

Spination. A comparative spination of leg IV in Dysdera crocata and D. balearica is given in table 4.

Male palp (figs 20–24): Tegulum shorter than distal division; posterior apophysis well developed, hooked, situated in upper half of distal division; distal division with strong median concavity, distal part bent at an angle of 30°; external sclerite narrow, gently curved, internal sclerite with broad base, slightly curved, on both sides with a crest at the pointed tip.

Epigastric fold region: Spermatheca visible in transparency as a transverse darker area.

Vulva (figs 27–28): Spermathecae three times as wide as it is long, but not as wide as in D. crocata . Dorsal arch with oblique margin. Transversal bar wide, twice as wide as spermatheca.

Comments. Dysdera balearica was described from Majorca by Thorell (1873). In the description, Thorell claims the species is “…very closely allied to D. maurusia Thorell, 1873 and D. crocata , especially the latter, but different from both”. The male palp is described in words, but no figures were given. The distal part of the bulbus is described “…the upper part or basis of the shaft tapers downwards…“, and this is one of the important diagnostic characters to distinguish D. balearica from D. crocata (see diagnosis). Later, Dysdera balearica was never cited again, except for a small footnote ( Simon 1914, page 112: “ D. balearica est aussi un synonyme probable de D. crocata ”). Although no proof was given for this synonymy, it was generally accepted. According to Řezáč et al. (2008) however, the synonymy of Dysdera balearica and D. crocata is doubtful. The type material of Dysdera balearica could not be found in any collection, including at the Swedish Museum of Natural History (T. Kronestedt, pers. comm.).

In a revision study, a neotype can be correctly designated if no holotype, lectotype, syntype or prior neotype is believed to exist. As first reviewers, here, we have selected an unidentified specimen from the BMNH, collected by D. J. Clark in 1971 in Majorca, as a neotype for Dysdera balearica .

Dysdera mordax L. Koch, 1882 was described from Majorca and only the male is known. Bosmans & Van Keer (2012) examined the holotype, but both palps were absent. Koch’s fig. 20 of the palp shows a bulbus with a tapering distal part, corresponding to the male neotype of D. balearica . No other epigean Dysdera species than D. crocata was found in Majorca. Based on these arguments, we consider Dysdera mordax L. Koch, 1882 a junior synonym of D. balearica Thorell, 1873 . From the shape of the bulbus, D. balearica does not resemble any other Dysdera from Spain, except perhaps D. flavitarsis Simon, 1882 as it has a tapering, pointed distal part of the bulbus, as shown in Simon’s sketch 161 of D. flavitarsa , the only figure available. This species needs redescription, but according to Arnedo (pers. comm.), the two species are clearly distinct.

New records. Majorca: Cala San Vicente (39°55’10’’N 13°3’16’’E), 1 ♀, 3–9.III.1971, D. J. Clark leg. ( BMNH); Parc natural de s’Albufera, 10m, 2 ♀♀, litter at border of salt marsh, 3.IV.2003 ( CRB); Pollença, Cala Boquer, 3 ♀♀, 10.III.1971, 5♀♀, 12.III.1971, D. J. Clark leg. ( BMNH, CRB); Valldemosa S., Torrent d’Avall, 1 ♂ 1♀, stones in Quercus forest, 4.IV.2003 ( CRB).

Distribution. Only known from Majorca.

Figures

FIGURES 17 – 24. Dysdera balearica Thorell, 1873; 17. Male, dorsal view; 18. Female, dorsal view; 19. Male prosoma, dorsal view; 20 – 21. Male palp, retrolateral view; 22. Idem, prolateral view; 23. Distal part of male palp, retrolateral view; 24. Idem, prolateral view.

FIGURES 27 – 30. Figs 27 – 28. Dysdera balearica Thorell, 1873; 27. VUlva, ventral view; 28. Idem, dorsal view. Fig. 29. Dysdera lata ReUss, 1834. VUlva, dorsal view. Figs 30 – 32. Dysdera arnedoi new species. 30. VUlva, dorsal view with transversal bar still in place; 31. Idem, ventral view; 32. Idem, dorsal view. Scale bars 0.2 mm.