Trabea

General description: 

"Definition. Small to large spiders ranging from 3.1 to 7.8mm in length. Sexes alike with slight colour dimorphism in some species. Carapace: Normally high with a markedly square-fronted appearance due to enlargement of second row eyes. Most species with two longitudinal brown bands extending from behind posterior eyes but a few without distinct markings. Eyes: Anterior row strongly procurved, laterals 1.1- 1.75 x diameter of medians and the eyes either equidistant or laterals further from medians than distance between medians. Second row  eyes much enlarged and 1.7-2.0 x width of anterior row. Width of posterior row greater than second row, eyes 0.6-0.8 x diameter of those of second row. The region of all eyes blackened. Chelicerae: Short (0.87-1.27 x depth of face) and relatively broad. Normally with three teeth on both margins but without obvious teeth on theanterior margin in T. heteroculata. Some species with characteristic dark markings. Maxillae and labium: Both relatively short and broad; labium 0.4-0.6 x length of maxilla. Sternum: Oval or scutate, usually somewhat produced between coxae IV. Legs: Of moderate length, either without markings or with vague rings and blotches of darker pigment. Spines long, stout and tapering, with sharp points. Ventral spines ofleg I: normally three pairs on metatarsus (exceptionally two) and three pairs on tibia (exceptionally four). Trabaea paradoxa and T, unicolor with a fringe of dark hairs beneath tibia I. Tarsi normally scopulate, claws of moderate length with three to six teeth. Patella and tibia IV 1.13-1.45 x metatarsus length. Abdomen: Most species with two dorsal longitudinal bands continuous with those on carapace, absent in a few species. Ranging from short and oval in T. rubriceps to long and narrow in T. ornutipalpis. Male palp: Fig. 1A-C. With a long, strapshaped 'terminal apophysis' the tip of which lies adjacent to the tip of the short, spike-like tegular apophysis. In the unexpanded palp the embolus lies beneath a transparent membranous portion of the tegulum which forms an extension stretching behind the 'terminal apophysis'. In some species the cymbium bears specialized flattened setae. Female epigyne: Fig. 2D. With a simple median plate, normally smoothly rounded posteriorly but pointed in T. ornutipalpis. Outline of spermathecae usually clearly visible through integument. Vulva: Fig. 1 1A-F. Both the size and position of the two sets of spermathecae show considerable variation between species." Russell-Smith, 1982

Biology: 

"Biology. Very little has been reported on the biology of Trabaea species. Trabaea paradoxa has been recorded from marshy ground and from dry, sandy areas in pine woods (Tongiorgi, 1968) and occurs along the Mediterranean littoral from Spain to Yugoslavia. I have observed the South African species 1. nigriceps runningactively in open grassland on a dry-hillside at Grahamstown. The raised carapace and black palps give this species a strong superficial resemblance to some of the southern African species of Pardosa such as P. crassipalpis Purcell. By ontrast T. ornutipalpis and T. rubriceps I have only found in shady places in tussocky plants and under stones. Trabaea heteroculata from East Africa and T. ornutipalpis appear at present to be restricted to montane areas where they have been found between 2000 and 3000m."  Russell-Smith, 1982

Phylogeny: 

"Af3’inities. Trabaea is very closely related to Chaleposa from which it may be distinguished by the raised and square-fronted carapace and markedly enlarged eyes of the seond row. Both the male palp and the female epigyne are extremely similar in the two genera and provide no clear-cut distinguishing features. The only other related genus in Africa known to me is Pterartoria Purcell. This genus also has a much enlarged ‘terminal apophysis’ which is, however, more complex in form and lies in close association with the tegular apophysis. It is probable that
these three genera, with a centre of distribution in southern Africa, form an isolated group not closely related to other lycosid genera." Russell-Smith, 1982

Distribution: 

"ZOOGEOGRAPHY

The genus Trabea seems to reach its highest diversity in South Africa with seven species occurring there. Besides this, two species are quite widespread in the Mediterranean area, north of the Sahara. Both these regions are amongst the better surveyed areas in Africa, and this might bias certain zoogeographical interpretations. In central and eastern Africa, four species are now known, two of which seem restricted to Malawi. Although extensive collections exist for instance from Congo (Zaire), only one Trabea species is known from that country. The diversity observed in Malawi is striking but not new. In several other spider families and other arthropod groups, the mountain forest relicts seem to contain a special fauna. The new T. setula found in Malawi, Nyika plateau is clearly closely related to T. purcelli known from the Cape. This again might be an indication of the historical connection between forested areas of both regions. However, there seems to be no reason why the genus should not be present in other geographically intermediate countries such as Zimbabwe, Botswana or Mozambique. As far as can be judged from the very poor biological data, most species are in no way restricted to forests (cf. Russell-Smith 1982). Both new species from Malawi are so far restricted to montane areas, as is the case for T. ornatipalpis from South Africa and T. heteroculata from Ruanda, Malawi and Tanzania. 

CHECKLIST OF PALAEARCTIC AND AFROTROPICAL TRABEA SPECIES 

The following valid species of Trabea are now known from the African continent andthe Mediterranean region: cazorla Snazell 1983 (Spain and north Africa, ? & / known), heteroculata Strand 1913 (Ruanda, Tanzania and Kenya, ? & / known), natalensis Russell-Smith 1982 (Natal, South Africa, only ? known), nigriceps Purcell 1903 (Cape, South Africa, ? & / known), nigristernis new species (Malawi, ? & / known), ornatipalpis Russell-Smith 1982 (Natal and Cape, South Africa, ? & / known), paradoxa Simon 1876 (Mediterranean Europe and north Africa, ? & / known), purcelli Roewer 1951 (Cape, South Africa, ? & / known), rubriceps Lawrence 1952 (Natal and Cape, South Africa, only / known), setula new species (Malawi, ? & / known), straeleni Roewer 1960 (Congo (Zaire), Ruanda, Malawi and Ethiopia, ? & / known), unicolor Purcell 1903 (Cape, South Africa, only ? known) and varia Purcell 1903 (Cape, South Africa, ? & / known)." Alderweireldt, 1999

Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith