Tidarren scenicum ( Thorell, 1899 ) Knoflach & Harten, 2006

Knoflach, Barbara & Harten, Antonius Van, 2006, The one-palped spider genera Tidarren and Echinotheridion in the Old World (Araneae, Theridiidae), with comparative remarks on Tidarren from America, Journal of Natural History 40 (25 - 26), pp. 1483-1616 : 1567-1571

publication ID	https://doi.org/ 10.1080/00222930600940993
persistent identifier	https://treatment.plazi.org/id/DC30557E-B316-A73F-FEF8-FA0EFF1DFE3E
treatment provided by	Felipe
scientific name	Tidarren scenicum ( Thorell, 1899 )
status	comb. nov.

Treatment

Tidarren scenicum ( Thorell, 1899) View in CoL nov. comb.

( Figures 178–180 View Figures 172–180 , 216–221 View Figures 216–221 , 259c View Figure 259 ; Table XXI)

Theridium scenicum Thorell 1899, p 24 ; n. sp., ♀, type locality Cameroon.

Theridion turrigerum Simon 1899, p 417 ; n. sp., ♀, type locality Cavally, Cote d’Ivoire. Nov. syn. Theridion guineense Simon 1907, p 40 ; n. sp., ♀, type locality Guinea-Bissau. Nov. syn.

Type material examined

Cameroon: 1♀, RMS No. 384 (type of T. scenicum ), leg. Sjöstedt, 1891 ( Thorell 1899). Cote d’Ivoire: 1♀, MNHN AR 2606 (type of Theridion turrigerum ), at upper river Cavally ‘‘Haut Cavally’’ at frontier post Zo, leg. Ch. van Cassel, September 1899 (‘‘Soudan français, au poste du Zo’’ according to Simon 1899; Mali according to Platnick 2006). Guinea-Bissau (‘‘Guinée portugaise’’): 1♀, MNHN AR 2369 (type of Theridion guineense ), Bolama, 11 ° 359N, 15 ° 289W ( Simon 1907).

Other material examined

South Africa: 1♀, NMBS, Swaziland , Mlilwane, Mlilwane Game Reserve, 20 km S Mbabane, 31 March 2001, 26 ° 229500S 31 ° 039400E, near house, leg. P. Horak. 1♀ shrivelled, CTh, Drakensberge , Royal Natal National Park, Gorge Pad, 6 June 2005, leg. G. Alberti.

Diagnosis and differentiation

Tidarren scenicum is the largest species in the Old World, carapace 1.4–1.6 mm wide. The abdomen ends in a high tubercle ( Figures 178–180 View Figures 172–180 ). Epigynal protuberance small and rounded, barely sclerotized, receptacula rather large ( Figures 216–221 View Figures 216–221 ). Male unknown.

Measurements (mm)

[Female from Guinea-Bissau (type of T. guineense )/ Cote d’Ivoire (type of T. turrigerum )/ South Africa, respectively.] Total length 5.79/5.36/4.73, carapace length 1.76/1.88/1.72, width 1.45/1.60/1.49, length femur I 3.60/3.72/3.72, tibia I 2.15/2.23/2.27. Abdomen 4.70/5.67/4.81 high, 3.52/3.80/3.21 long, and 3.13/3.21/2.78 wide. Ventral side (distance petiolus to spinnerets) 2.74/2.78/2.50 long. Clypeus 0.43–0.45 high, chelicerae 0.57–0.66 long. Sternum 0.98–1.13 long and 0.86–0.88 wide. Gnathocoxae 0.53–0.55 long and 0.21– 0.25 wide, labium 0.18–0.20 long and 0.37–0.39 wide. Leg formula 1423, see Table XXI.

Somatic features, colouration ( Figures 178–180 View Figures 172–180 )

[Based on females from Cote d’Ivoire, Guinea-Bissau, and South Africa.] Sternum without posterior tubercle. Abdomen higher than long, forming a large dorsal hump ( Figures 178, 180 View Figures 172–180 ), so that the species name T. turrigerum chosen by Simon (1899) would be apposite. Carapace light yellow with broad dark margins and dark brown median band ( Figure 179 View Figures 172–180 ), which branches laterally at centre of carapace. Chelicerae light brown, labium and gnathocoxae light yellow. Sternum light yellow with dark patches at margins and some median spots. Legs and pedipalps light yellow with dark patches and annulations, especially femur, tibia, and metatarsus I covered with numerous fine dots. Abdomen brownish, with white guanin markings and some dark pigmentation; broad and light dorsal median area outlined by distinct white stripes, which branch laterally and end shortly before tip of abdomen; surrounding lateral area darker. Aboral field whitish, partially overlain by dark pigmentation, with distinct white median stripe from apex to spinnerets. Epigastric region light, book lung covers light yellow. Venter uniformly light brown or with a few white patches. Spinnerets light brown. The type of T. guineense is largely light yellow and perhaps partially faded ( Figure 180 View Figures 172–180 ), though Simon (1907) mentioned the light yellow colouration.

Epigynum, vulva ( Figures 216–221 View Figures 216–221 )

Epigynal protuberance rounded, short in comparison with body size ( Figures 178, 180 View Figures 172–180 , 216, 217 View Figures 216–221 ), ca 0.11–0.12 mm long, directed posteriorly; protuberance whitish, scarcely sclerotized, in contrast to surrounding sclerotized integument. In aboral view protuberance clearly delimited from surrounding integument ( Figure 221 View Figures 216–221 ). Copulatory ducts fused to tiny atrium at entrance ( Figures 218, 219 View Figures 216–221 ), short, 0.14 mm long. Copulatory orifice at anterior border of epigynal protuberance, in ventral view behind posterior end of receptacula. Copulatory ducts run foward for a short distance and abruptly diverge laterally. They enter receptacula posteriorly, at inner side ( Figure 220 View Figures 216–221 ). Receptacula seminis large, 0.27–0.32 mm long and 0.16–0.21 mm wide. Epigynal protuberance less than half length of receptacula ( Figures 218, 219 View Figures 216–221 ).

Distribution ( Figure 259c View Figure 259 )

Tidarren scenicum , although known from five females only, appears to be widespread in Africa.

Synonymy

Both Tidarren turrigerum Simon, 1899 and T. guineense Simon, 1907 correspond well with the type of T. scenicum Thorell, 1899 in body dimensions, shape of abdomen and of epigynum, and are therefore considered as synonyms. Tidarren fornicatum was described from a juvenile female from Sudan (sub Theridion fornicatum ; Simon 1884). General appearance, especially the large abdominal hump, agrees with the female of T. scenicum . Nevertheless, this species should not be proposed as a senior synonym without knowledge of the genitalia. Otherwise, T. fornicatum would have priority. Further material from the type region would probably clarify this problem.

Theridion turrigerum Simon and T. scenicum Thorell are clearly synonyms, but were both described in 1899. The exact date of publication should decide on the priority. Thorell’s paper was almost certainly printed in 1899. It is the first part of Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar, Volume 25, Section IV, Zoology. This volume contains six independently paginated papers, each with a separate title page, papers 1–3 having the printing year 1899 and papers 4–6 1900 (T. Kronestedt, in litt.). The ‘‘communicatum’’ date of the reprint, 8 February 1899, has nothing to do with the printing date but indicates that the paper was presented to the academy early in 1899 and thus was almost certainly printed in the same year (T. Kronestedt, in litt.). The footnote on the reprint of Simon’s work, ‘‘Imprimerie nationale— Janvier 1900 ’’ indicates that the actual date of publication was later. For this reason, T. scenicum has to be considered the valid name. Localization of the type locality of T. turrigerum appears to be arguable. According to Simon (1899) it was collected from ‘‘ Soudan français’’, which would be partially consistent with Mali ( Platnick 2006). Yet, when trying to locate the ‘‘frontier post’’ Zo at the river Cavally, it appears more likely to match Cote d’Ivoire.

Simon (1907) indicated a close relationship between T. turrigerum and T. scenicum , but his T. scenicum now turns out to be a female of T. cuneolatum (from Guinea-Bissau, MNHN AR 2370), see above. Therefore, it is not surprising that he distinguished T. turrigerum by its larger size, although being as large as the proper T. scenicum , and by the obtuse epigynal shape.