Brigittea Lehtinen, 1967

Marusik, Yuri M., Esyunin, Sergei L. & Tuneva, Tatyana K., 2015, A survey of Palaearctic Dictynidae (Araneae). 1. Taxonomic notes on Dictynomorpha Spassky, 1939, Brigittea Lehtinen, 1967 and Lathys Simon, 1884, Zootaxa 3925 (1), pp. 129-144 : 135-136

Brigittea Lehtinen, 1967 , reinstated

Brigittea Lehtinen 1967: 219 , 360. Brigittea: Miller & Svatoň 1978: 9 . Dictyna: Wunderlich 1987: 224 .

Type species: Aranea latens Fabricius, 1775 [= B. latens ].

Diagnosis. Brigittea is the only genus among Dictyninae with ctenidia on the male palpal tibia and a bipartite cribellum.

Comments. The genus was created for eight species B. latens (Fabricius, 1775) (♂♀, West Palaearctic), B. civica (Lucas, 1850) (♂♀, West Palaearctic), B. denisi Lehtinen, 1967 (♂♀, Niger), B. innocens (O. Pickard- Cambridge, 1872) (♂♀, West Palaearctic), B. turbida ( Simon, 1905) (♀, India & Sri Lanka), B. tullgreni (Caporiacco, 1949) (♂, Kenya), B. vicina (Simon, 1873) (♂♀,West Palaearctic) and B. umai (Tikader, 1966) (♂♀, India). Lehtinen (1967) created a table with characters for 23 Dictynidae genera. According to this table, Brigittea , unlike Dictyna , has a bipartite cribellum, ventral boss and anterior teeth on the male chelicerae, and a spiraled structure of the vulva.

Miller & Svatoň (1978) revised European Brigittea and provided an additional character that separates this genus from Dictyna – widely separated receptacles [contiguous in the type species, D. arundinacea (Linnaeus, 1758) and related species].

Merrett et al. (1985), in a faunistic paper, doubted the validity of Brigittea stating that “ D. [ictyna] latens was included in the new genus Brigittea by Lehtinen (1967) on account of its bipartite cribellum and palpal characters; this was followed by Brignoli (1983), but since there seems to be some doubt about the validity of this genus we have decided to leave latens in Dictyna for the present”. Wunderlich (1987) used these arguments in favour of a formal synonymy of the two genera and suggested that this taxon be regarded as the “ Dictyna latens -Gruppe”. He extended this group to eight species by adding D. guanchae Schmidt, 1968 and D. agaetensis Wunderlich, 1987 (currently these names are considered as synonyms).

However, while studying Dictynidae from Kazakhstan, we found additional characters which support the validity of Brigittea . The male palp in all Dictyninae and partially in Tricholathysinae has a very similar conformation; therefore somatic characters play an important role in the recognition of these genera.

The bipartite cribellum is known in only five genera of Dictyninae and was not reported in Tricholathysinae. Brigittea is the only genus among Dictyninae with ctenidia on the male palpal tibia and a bipartite cribellum. The cribellum of Brigittea has only one anterior row of setae (As), whereas the remaining cribellate area is covered only with fine spigots (Fs). This contrasts with that in Dictyna in which the anterior two-thirds of the cribellum is covered with setae and one third with fine spigots.

The male chelicerae each have a distinct baso-lateral tooth (Bt) in Brigittea ( Fig 33 ) which is weakly developed in Dictyna . Such a tooth is found not only in the type species, but well documented for B. innocens ( IJland et al. 2012: fig. 4) and B. guanchae ( Wunderlich 1987: fig. 590) as well. Brigittea latens has also cheliceral teeth (Ct) lacking in Dictyna arundinacea (cf. Figs 28, 33 ). The cheliceral ridge (Cr) of the type species of Dictyna and Brigittea also differs in its length. Also, the profile of the chelicera in Dictyna is strongly concave ( Fig. 28 ), while in Brigittea it is almost straight ( Fig. 33 ) or convex (pl. IV, fig. 1 in Miller & Svatoň 1978).

The type species of both genera differ essentially in their structure of the ctenidia. In Dictyna , ctenidia are set in separate alveoli, while in Brigittea , they are located in the same alveolus. The ctenidia in D. arundinacea have distinct micro-ridges which are lacking in B. latens . The tip of the lower arm of the conductor is also different in D. arundinacea and B. latens , but this difference is not important as the shape of this tip in Dictyna is very variable. More important differences are found in the shape of embolus. In Dictyna , it is filamentous and the tip is gradually tapering, while in B. latens it is modified ( Fig. 36 ). This character was overlooked by Lehtinen (1967) and Miller & Svatoň (1978). A modified embolus might prove to be the “best” character that separates the two very similar genera Dictyna and Emblyna ( Lehtinen 1967) .

Equally, the epigynes of D. arundinacea and B. latens are entirely different in all respects. Brigittea latens has no epigynal sulci, which are present in all Dictyna sensu stricto. Brigittea civica and B. vicina have sulci, although they are much shorter than in Dictyna . The most significant differences lie in the shape of “receptacles”, which are contiguous in Dictyna and forming a V-shaped structure together with the ducts; in contrast, in Brigittea , the receptacles do not touch each other and together with ducts form a spiraled (coiled) structure.

Based on the reasons mentioned above, we decided to resurrect Brigittea as a valid genus with following species: B. latens , B. civica , B. innocens , B. vicina and B. guanchae (Schmidt, 1968) , comb. n. (ex Dictyna ) from the Canary Islands. The latter species was attributed to the Dictyna latens group by Wunderlich (1987).

Four species from Afrotropical and South Asian regions considered in Brigittea by Lehtinen (1967) ( D. denisi , D. turbida , D. tullgreni and D. umai ) remain in Dictyna . These species are not properly known and their descriptions lack information about a divided cribellum or modified chelicera.

Figures

FIGURES 26 – 36. Dictyna arundinacea (26 – 30), Brigittea latens (31 – 36). 26, 31 Male palp, ventral. 27, 32 Ctenidia, dorsoretrolateral. 28, 33 Chelicera, mesal. 29, 34 Tip of conductor, retrolateral. 30, 35 Same, ventral. 36 Tip of embolus. Abbreviations: Bt—retrobasal tooth of chelicera; Cr—cheliceral ridge; Ct—cheliceral teeth.