Science Engineering and Agriculture

The Afrotropical representatives of the spider genus Simorcus Simon, 1895 are revised. The genus belongs to the subfamily Strophiinae and is known from the Afrotropical and the Oriental Regions. The genus Simorcus is redescribed and twelve species are keyed out, with six species known from one sex only. Nine species are described as new:

The male of Nesiergus insulanus Simon, 1903 is described for the first time, and both sexes are illustrated. The presence of the species on the two Seychelles islands of Frégate and L’Îlot Frégate is confirmed, and observation evidence suggests that its range extends to Cousine Island.

Elephant impacts on spider assemblages, and the potential use of spiders as indicators of habitat changes was assessed in central Maputaland, South Africa. Three habitats, namely undisturbed sand forest, elephant disturbed sand forest and mixed woodland, were sampled. To ensure a thorough representation of all spider guilds, spiders were collected by tree beating, sweep netting, active searching, leaf litter sifting and pitfall traps. In total, 2808 individual spiders, representing 36 families, 144 determined genera and 251 species were collected. Spider abundance was highest in the undisturbed sand forest (n = 1129, S = 179), followed by elephant disturbed sand forest (n = 1006, S = 165) and mixed woodland (n = 673, S = 171). Assemblages of the two sand forests were more similar than to the mixed woodland assemblage. Active hunting species were indicators of the more open vegetation of elephant disturbed sand forest (six active hunters, no web-builders) and mixed woodland (ten active hunters, one web-builder), whereas web-builders are indicators of the dense, complex vegetation structure of undisturbed sand forest (six web-builders, three active hunters). Elephant-induced changes to the vegetation structure in this high diversity, high endemism region result in changes in the composition of spider assemblages, and may need to be mitigated by management intervention.

A survey of ground-living spiders was conducted over a one-year period at Ngome State Forest, KwazulalNatal. Five different habitat types: grass, open forest, dense forest, ecotone and pine, were sampled with 180 pitfall traps. The grass, open forest and dense forest represented indigenous vegetation while the pine represented exotic vegetation. The ecotone consisted of a mixture of indigenous forest plants and pine trees. Pine had the lowest spider diversity while grass had the highest spider diversity. However, variation in spider diversity within habitat types was considerable and an analysis of variance found no significant difference in mean values of spider diversity between habitat types. Consequently, the results do not unambiguously support the hypothesis that exotic vegetation has lower ground-living spider diversity than indigenous vegetation.

The Orapa kimberlite pipe, situated in north-central Botswana, is well-known for its rich reserves of diamonds. It is indeed one of the largest and richest diamond mines in the world. The kimberlite magma transporting the diamonds from the upper mantle erupted through a sequence ofKaroo-aged rocks before the deposition ofthe Kalahari Sands. This eruption has been radiometrically dated at early Late Cretaceous (Cenomanian-Coniacian). When volcanism ceased, a succession of epiclastic crater lake sediments was deposited above the kimberlite plug. Analysis of these sediments, which mostly comprise the results of mudflows and debris flows and fmer sediments during quiescenttimes, suggests that most of the sediments within the crater were deposited rapidly as mass flows, and were therefore mobilised soon after the volcanic eruption. Buried within the fme-grained sediments is a unique assemblage of fossils including flowering plants and many whole-bodied insects. The fossils are commonly exquisitely preserved in extremely fme-grained mudstone. Interpretation of the sedimentary facies and fossils is that the mid-Cretaceous climate of central Botswana was temperate, seasonal and wet, and the area surrounding the crater was forested. The fossils represent the recovery of the biota of the area after the violent eruptions of Orapa and other nearby kimberlite fissures and pipes. The fossils have contributed considerably to our understanding of mid-Cretaceous insects and flowering plants and suggest intimate relationships between the two at an early stage in the radiation of flowering plants. It seems that southern Gondwana (including southern Africa) was a centre of diversification for both insects and angiosperms in the mid-Cretaceous.

The inclusion of spiders in conservation planning initiatives is confounded by several factors. Surrogates might provide a viable alternative for their inclusion. In this paper we investigate the performance of a number of surrogate measures, such as higher taxa (genus, family), cross-taxon surrogates that are subsets of the spider assemblages (certain spider families) or non-overlapping groups (woody vegetation and birds), and the use of morphospecies. Birds and woody vegetation were included because they often form the focus of conservation planning initiatives. We assessed the surrogate measures based on their predictive power for species richness and extent to which conservation planning that maximizes representation of the surrogate is effective in representing spider diversity. A measure for the latter is the species accumulation index (SAI). Generic richness as a higher taxon surrogate and the combined richness of the families Thomisidae and Salticidae were the best estimators of total species richness. Based on the surrogacy efficiency criterion, genera and the family Salticidae had species accumulation indices (SAI) that were significantly larger than 95 % confidence intervals of a random curve, while woody vegetation and birds turned out to be poor surrogates for spider diversity. The use of morphospecies as estimators is cautiously supported (adjusted R2 = 0.85, for species richness, SAI = 0.73). The surrogates identified here provide a viable alternative to whole assemblage analysis but should be used with caution. The use of genera is confounded by unstable taxonomy and the difficulty of identifying specimens up to genus level. Geographic location and varying sampling effort between surveys did not have an effect on the surrogate performance of the two spider families, viz. Salticidae and Thomisidae. The former family has seen a flood of recent systematic work, whereas the latter's taxonomy is fairly well developed. These two families comprise ca. 20% of spider species observed in the Savanna Biome of South Africa and could provide a viable handle on spider diversity in this region.

Two common South American species of lynx spiders, Peucetia rubrolineata and P. flava (Oxyopidae), were surveyed on three localities in southeastern Brazil to determine plant choice. Both species were found to be associated with plants bearing glandular trichomes. A literature review and complementary data show that ten Peucetia species are associated with up to 55 plant species bearing glandular trichomes in at least 20 distinct vegetation types (phytophysiognomies) in more than 36 localities in the Neotropical, Neartic, Afrotropical, and Paleartic regions. The main plant families used by the spiders were Solanaceae, Asteraceae, and Melastomataceae. The specialization of the Peucetia species for plants bearing glandular trichomes may have evolved because insects adhered to these sticky structures may be used as prey by the spiders.

Lycosidae (64.3%), Gnaphosidae (9.0%), Zodariidae (5.3%), Linyphiidae (4.7%) and Salticidae (3.1%). 4. Grazing intensity and fire frequency had no measurable effect on ground-dwelling spider abundance diversity or assemblage structure. Only when rare or single species occurrence was included, was there some form of association with sites. This study has provided for the first preliminary inventory of ground-dwelling spiders for this habitat.

Invasions by alien plants into unspoiled ecosystems are a cause for concern because the pristine systems are important stores of biodiversity. Indeed, the introduction of non-indigenous species into protected areas is a direct threat to conservation. Consequently, it is fundamental to document the impact that alien invasive plants have on native communities and to determine if, and at what rate, native communities re-establish following the removal of invasives. 2. Chromolaena odorata is one of the most important invader species in the savanna biome in South Africa. It reduces vegetation heterogeneity in grasslands, savannas and forests. 3. Spiders, as ecological indicators for change, were used to investigate the impact of (i) C. odorata invasions, (ii) C. odorata invasion durations, and (iii) the impact of clearing C. odorata on abundance, assemblage patterns, diversity and estimated species richness of spiders. 4. The progressive invasion of C. odorata with increasing invasion duration brings with it changes in native spider abundance, assemblage patterns, diversity and estimated species richness. Native spider assemblages do re-establish after clearing C. odorata without further management intervention. Small lingering differences are observed between the native and the cleared sites, suggesting that other features of the habitat may have been affected by the invasion and clearing. 5. Synthesis and applications. Alien clearance is an essential and invaluable management tool. There are a substantial number of programmes that aim to control alien invasive plants but very little is known about the way in which biodiversity recovers after alien plant removal. Our data show that the removal of alien invasive plants benefits biodiversity with immediate effects, highlighting that management should be carried out to control this invasive, even if the area has been invaded for a long period of time. These data are important for policy-forming and informing policy-makers that alien invasion and removal are critical for biodiversity conservation management.

Ground-dwelling arthropods are important in agroecosystems, with some species having the potential to reduce populations of both weed and insect pests (Thiele 1977; Cardina et al. 1996). These organisms also play an integral part in above-and below-ground food webs and can impact on litter decomposition

Members of genus Ammoxenus are known predators of harvester termites (Hodotermes mossambicus). An A. amphalodes female was observed catching and paralyzing a termite in the field. The paralyzed termite was deposited in a silk sac with other paralyzed termites. This confirms that Ammoxenus spp. use different methods of catching and utilizing prey. Termites are either killed and fed upon or paralyzed and stored for feeding at a later time.

Invertebrates include more than 80% of all animals, yet they are severely under-represented in studies of southern African diversity. Site biodiversity estimates that do not consider invertebrates, not only omit the greatest part of what they are attempting to measure, but also ignore major contributors to essential ecosystem processes. All available information on spider species distribution in the South African Savanna Biome was compiled. This is the largest biome in the country,occupying over one third of the surface area.A total of 1230 species represented by 381genera and 62 families are known from the biome. The last decade has seen an exponential growth in the knowledge of the group in South Africa, but there certainly are several more species that have to be discovered, and the distribution patterns of those listed are partly unknown. Information is summarized for all quarter degree squares of the biome and reveals considerable inequalities in knowledge. At a large scale the eastern region is much better surveyed than the western parts, but at smaller scales throughout the region, several areas have little information. A total of 928 spp. (75%) are free-living spiders with 571 spp. living on the soil surface, including those living in burrows (73 spp.), and 357 spp. that are associated with vegetation. The web dwellers are represented by 302 spp., with the largest number making orbwebs (123 spp.), followed by the retreat-web spiders (61 spp.) and the sheet-web spiders (39 spp.).The Salticidae is the most diverse family (159 spp.) and also has the most endemic savanna species (42 spp.), followed by Thomisidae (116 spp.). The Endemicity Index indicates that 366 species are endemic to the biome,with 322 species that are near endemics, i.e. also occurring in an adjacent biome. An abundance index (1-3) was also calculated for each species based on numbers sampled. The two indices were combined into a rarity index for each species, which gives a preliminary indication of the conservation importance of each savanna species. Information is also available on species presently protected in protected areas in the Savanna Biome and species known to playa role as predators in agro-ecosystems found within the biome.

Among other activities, the South African National Survey of Arachnida (SANSA) aims to survey the biodiversity of arachnids in protected areas of South Africa. The study presented here documents the diversity of spiders and scorpions collected from the Nylsvley Nature Reserve (NNR), South Africa over a 30-year period. The spider fauna of NNR contains 175 species (7.5% of the total recorded in South Africa), in 131 genera and 37 families. Thomisidae is the most diverse spider family in the reserve, with 33 species (18.9% of the total), followed by Salticidae, with 20 species (11.4%), and Araneidae, with 18 species (10.3%). The majority of species (125) are wandering spiders (71.4%), whereas 50 species (28.6%) build webs. Wandering grounddwelling spiders comprise 52 species, whereas 73 wandering species have been collected from the vegetation. A total of 158 species are new records for the reserve and Oxyopes tuberculatus Lessert, 1915 is newly recorded for South Africa. Six spider sp...

The Afrotropical species of the genus Tibellus Simon, 1875, are revised. Of the 10 previously recognised species of long-bodied grss spiders from this region, eight are redescribed and figured. Two species, T. punctifasciatus Strand, 1906, and T. robustus Simon, 1886, are considered nomina dubia. Five new species, T. cobusi, T. gerhardi, T. nimbaensis, T. somaliensis and T. sunetae, are described and three previously recognised subspecies of T. vossioni Simon, 1884, namely T. v. armatus Lessert, 1928, T. v. flavipes Caporiacco, 1941, and T. v. minor Lessert, 1919, are given species status. The genus Tibellinus Simon, 1910, is a junior synonym of Tibellus. Tibellinus australis is transferred to the genus Tibellus. The males of T. armatus stat. nov. and T. hollidayi Lawrence, 1952, are described for the first time. A key to 17 recognised species is given. Distributional data are provided for all species.

The African genus Ceratogyrus of the family Theraphosidae is revised, with notes of its natural history. Seven species are recognised and distinguished in a key. Six species, namely C. bechuanicus Pocock, C. brachycephalus Hewitt, C. darlingii Pocock, C. dolichocephalus Hewitt, C. marshalli Pocock and C. sanderi Strand are redescribed and figured, C. cornuatus is newly described and figured and C. schultzei Pocock is synonymized with C. bechuanicus. Lectotypes are designated for four species namely, C. brachycephalus, C. darlingii, C. dolichocephalus and C. marshalli. Distributional data is given for all seven species.

South Africa has a rich spider fauna with 66 families represented by more than 5 000 species. In the past two decades both specialists and laymen have shown considerable interest in spiders. Although scientific names of the different species are available, these are usually known only to specialists. For the layman the scientific name has little meaning. The main objective of this list is to link a specific vernacular name to a particular taxon to eliminate confusion and to assist the layman. All available publications and reports, both local and those from abroad were perused to compile the list. Most of the names were available in English but due to the need for common names in Afrikaans they were translated. Although this list is not exhaustive, it may serve as a basis for a more complete list to be compiled in future. The pre- liminary list was submitted to arachnid specialists throughout the Republic of South Africa for comment and emendation. The common name recommended for us...

Invertebrates constitute a substantial proportion of terrestrial and freshwater biodiversity and are critical to ecosystem function. However, their inclusion in biodiversity monitoring and conservation planning and management has lagged behind better-known, more widely appreciated taxa. Significant progress in invertebrate surveys, systematics and bioindication, both globally and locally, means that their use in biodiversity monitoring and conservation is becoming increasingly feasible. Here we outline challenges and solutions to the integration of invertebrates into biodiversity management objectives and monitoring in protected areas in South Africa. We show that such integration is relevant and possible, and assess the relative suitability of seven key taxa in this context. Finally, we outline a series of recommendations for mainstreaming invertebrates in conservation planning, surveys and monitoring in and around protected areas.Conservation implications: Invertebrates constitute...

The spider genera Mystaria Simon, 1895 and Paramystaria Lessert, 1919 are revised (Mystarini: Thomisidae). About 400 individuals were studied. The approach followed was classical taxonomy using illustrated sexual dimorphic copulatory characters and described morphological characters, photographed or measured. Paramystaria is considered a junior synonym of Mystaria, based on similarity to the type M. rufolimbata Simon, 1895 but with the exclusion of M. unicolor Simon, 1895, a species last studied in 1895. Mystaria unicolor is re-described and placed in a new genus, Leroya gen. n., together with L. silva sp. n. (♂♀, DRC) which is recognised as the type species. Mystaria now contains 13 well-defined species, four of which are in new generic combinations. Four males are described for the first time, and eight new species. Re-described species include M.