A check list of the spider fauna of the Western Soutpansberg , South Africa ( Arachnida : Araneae )

By virtue of its geological history and geographical location the Soutpansberg constitutes a refuge for a high diversity of organisms. The Western Soutpansberg forms part of the Savanna Biome and is presently the area with the highest concentration of Natural Heritage Sites in South Africa. A unique private initiative is under way to improve its national and international conservation status in a bid to conserve the mountain. A checklist of the spider species of the Western Soutpansberg collected over a five-year period is presented. Forty-six families, represented by 109 genera and 127 species have been collected. Of the species collected, 81 (64 %) were wandering spiders and 46 (36 %) web builders. The Thomisidae have the highest number of species (15) followed by the Araneidae and the Salticidae with 10 species each. Ninety-six genera are represented by a single species. Ninety six percent of the species collected are new records for the area. This survey is the first for the area and forms part of the South African National Survey of Arachnida (SANSA).


Introduction
In ratifying Agenda 21 at the Earth summit in Rio de Janeiro (1992) and the convention on biological diversity in 1995, South Africa is obliged to develop a strategic plan for the conservation and sustainable use of biodiversity.However, meaningful conservation cannot take place if the species involved are not known.Although Araneae constitutes an abundant and highly successful group of invertebrates, little is known about their diversity in large parts of South Africa.Compared with areas in the Northern Hemisphere ecological surveys of African spiders are sparse (Dippenaar-Schoeman & Jocqué 1997), This is also true for spider fauna in conserved areas with the only check lists compiled being those for the Mountain Zebra National Park (Dippenaar-Schoeman 1988), Roodeplaat Dam Nature Reserve (Dippe-naar- Schoeman et al. 1989), Karoo National Park (Dippenaar-Schoeman et al. 1999) and Makelali Nature Reserve in the Limpopo Province (Whitmore et al. 2001).In 1997, the South African National Survey (SANSA) was initiated.One of its aims is to make inventories of the arachnid fauna of South Africa (Dippenaar-Schoeman & Craemer 2000).As part of SANSA, various projects are in progress, such as inventories of the spider fauna in different floral biomes and to determine the number of species that are already protected in existing conservation areas.
The Limpopo Province is often perceived as savanna and bushveld, however, the Soutpansberg mistbelt has a totally unique composition of plants, animals, and invertebrates.By virtue of its geological history and geographical location the Soutpansberg moun-tain archipelago constitutes a refuge for a disproportionately high diversity of organisms.The floral environment is very diverse, with a higher generic diversity than that of the Cape Flora and include the following: savannah bushveld, indigenous forests with ancient yellowwood trees, very 'sensitive wetlands', and Soutpansberg fynbos similar to that found in the Western Cape (Hahn pers. comm.).The Western Soutpansberg is presently the area with the highest concentration of Natural Heritage Sites in South Africa and is part of a unique private initiative to improve its national and international conservation status in a bid to conserve the mountain (Rosmarin et al. 1998).This involves the establishment of various reserves and a conservancy.A process is also in motion to get the Soutpansberg recognized as a World Heritage Site and also to include it in UNESCO's man and biosphere program as a Biosphere Reserve.
The eastern part of the Soutpansberg, especially the area around the Hanglip Forest, has been fairy well sampled and numerous species described.However, very little is known about the western part.In this study an inventory was made of spider species present in the Western Soutpansberg.Spiders were collected from various habitats over a 5-year period.This is the first inventory of the spiders from the Western Soutpansberg.It is a contribution towards the Soutpansberg conservancy objectives and also forms part of the South African National Survey of Arachnida (SANSA) for the Limpopo Province and Savanna Biome.

Study area
The Soutpansberg is the northernmost mountain range in South Africa, situated within the Limpopo Province and stretches about 100 km in an east-west direction.The Western Soutpansberg, which this survey deals with, stretches from the Sand River, which is near Louis Trichardt to the town of Vivo about 70 km west (Fig. 1).

Materials and methods
Sporadic collecting was mainly undertaken from 1996-2000.Spiders were sampled by hand (plant and ground search, turning rocks, and sifting of leaf litter) or using a sweepnet or beating tray for grass and low shrubs.Pitfall trapping was undertaken for a 10-week period (from 3 May 1997-13 July 1997), with 50 pitfall traps in an old and secondary growth forest at the farm Lajuma.Since collecting for the current study was on an ad hoc basis for relatively short periods, the results may not reflect the true diversity and species richness of the area, but nevertheless, they give an indication of species present (minimum community).It is also important to note that most of the collecting took place on the farm Lajuma, restricting most of the collecting to an area < 500 ha.The material collected was identified by the second author and is housed in the National Collection of Arachnida (NCA) at the ARC-Plant Protection Research Institute in Pretoria.

Numbers present
During the five-year survey a total of 46 families represented by 109 genera and 127 species were collected (Table 3).Of the species collected 81 (64%) were wandering spiders and 46 (36%) web builders.All the species are new records for the Western Soutpansberg.The Thomisidae had the highest number of species (15) followed by the Araneidae and Salticidae each with 10 species, and the Gnaphosidae with eight.
Ninety-six genera are each represented by a single species.One new species, the miturgid, Cheiromiona lajuma, has been described, and some undetermined species might be new to science e.g.Poecilomigas sp. and Mimetus sp.However, only after revisionary studies could this be determined.

Ground layer
Twenty-eight families, represented by 53 species are associated with the ground layer (Tables 2 & 3).
Ground web dwellers: 15 species make their webs on or close to the ground surface.The following web dwellers were found: the funnel-webs of the Guilds: FGW = free living ground wanderers; BGW = burrow living ground wanderers; FPW = free living plant wanderers; BPW = burrow living plant wanderers.

Field layer
Plant web dwellers: from the field layer 42 % of the species collected were associated with webs (Table 2).The orb-web spiders were represented by five families (16 spp.) with the Araneidae the more abundant (10 species).Representatives of some rare families, such as Anapidae and Mysmenidae have also been collected.Little is known about these families in South Africa and both probably represent new species.Several of the orb webs constructed where large and made by members of the tetragnathids, the golden orb-web spiders (Nephila) and two silver vlei spider species of the genus Leucage.The physical structure of the habitat plays a role in the composition of the spider web dwellers (Wise 1993) as it not only provides the necessary support for anchoring webs but also increases the availability of retreat space and lead to the modifification of microclimate, which could have an effect on the spiders as well as their prey.
Plant burrow dwellers: the nemesid trapdoor spider Entypesa schoutedeni Benoit was collected from transparent webbing from under bark.The type locality of this species, is Soutpansberg, but no exact locality was indicated.This species seems to be endemic to the Soutpansberg.The migid also known as the tree trapdoor spider probably belongs to a new species of Poecilomigas (Griswold pers.comm.).The genus makes sac-like burrows beneath the bark with a wafer-lid trapdoor (Dippenaar-Schoeman 2002).This is the first record of the genus from the Limpopo Province.
Free-living plant wanderers: 55 % of all spiders collected from the field layer were freeliving spiders.1988) and it is accepted that eco-tourism will be one of the primary future land uses within the Soutpansberg Conservancy area.To this end an overall eco-tourism theme that retains and enhances the uniqueness of the area should be striven for.Spiders may play an important role here.

Table 3
Ecological and behavioural classification of spider taxa (Dippenaar-Schoeman et al. 1999) Check list of spiders of the Western Soutpansberg region collected from 1996 to 2000 Agelenidae and sheetwebs of the Hahniidae are made mainly in open grass areas; retreat-webs of the families Amaurobiidae (Pseudauximus), Eresidae (Penestomus), Hersiliidae (Tama), Oecobiidae (Uroecobius) and Phyxelididae (Vidole) are made on or below rocks; space-webs of the Pholcidae is made in old mammal-made holes and in dark crevices and the gum-foot web of a Steatoda sp. of the Theridiidae are made under stones.This is the first record of Penestomus (Eresidae) and Tama (Hersiliidae) collected outside the Cape Provinces ISSN 0075-6458 37 Koedoe 45/2 (2002)Table 1 idae, Idiopidae, and two baboon spiders of the family Theraphosidae.Homostola pardalina (Hewitt) (Cyrtaucheniidae) is the first record of this genus from the Limpopo ISSN 0075-6458Free-living ground wanderers: most ground dwellers (64 %) are free-living species that are not constructing webs to catch their prey (Table2).The families Gnaphosidae, with eight species, and Lycosidae with four, are

Table 3
Balmford et al. 1996) by nine families and 34 species.Most species were collected with sweepnets from grass.This is the first survey of the spiders of the Western Soutpansberg.About 96 % of the species collected are new records for the area with 10 possibly new species.The 127 species probably represents only a portion of the spider fauna present.However, it compares well with other more comprehensive surveys that have been undertaken in South Africa for example: Roodepaat Dam Nature Reserve (98 spp,), Rietondale Research Station (55 spp.), the Karoo National Park (116 spp.), and Kruger National Park (139 spp.).At family level, the spider fauna from the Western Soutpansberg is more diverse than any of the above surveys.A direct positive correlation between family and species diversity has been observed for other taxa (Andersen 1995;Balmford et al. 1996), pointing to a disproportionately high spider diversity for this area and higher biological diversity in terms of kinds and disparity of attributes of species.Although the Araneae are an abundant and highly successful group of invertebrate animals, little has been done to conserve them in South Africa.With this rich fauna of spiders present, it fulfils the objectives of the Western Soutpansberg Conservancy.An awareness of spiders present might stimulate additional collecting and more research.In the past two decades both specialists and laymen have shown considerable interest in spiders (Dippenaar-Schoeman & Van den Berg