1,828 research outputs found

    On ant-like Synemosyna Hentz, 1846 spiders from Bolivia, with indirect evidence for polymorphic mimicry complexes (Araneae: Salticidae: Simonellini)

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    Three species of Synemosyna Hentz, 1846 were recorded during a survey in five Bolivian forest ecoregions: S. aurantiaca (Mello-Leitão, 1917), S. myrmeciaeformis (Taczanowski, 1871) and S. nicaraguaensis Cutler, 1993. Synemosyna aurantiaca and S. nicaraguaensis are recorded for Bolivia for the first time and the previously unknown male of S. nicaraguaensis is described and illustrated. The habitus and the genitalia of the female of S. myrmeciaeformis are illustrated for the first time. Synemosyna aurantiaca occurs in semi-deciduous forests south of 18° S and S. myrmeciaeformis in the Bolivian Yungas forest and ecoregions of the Amazon biome north of 16° S. Synemosyna nicaraguaensis is possibly an Andean species that enters into the moist Isthmian forests of Central America. Several potential mimicry complexes with two broad patterns were observed: sex-specific polychromatic mimicry (S. nicaraguaensis), and transformational mimicry involving smaller orange and larger brown to dark-brown forms (S. aurantiaca and S. myrmeciaeformis).Fil: Perger, Robert. Colección Boliviana de Fauna; BoliviaFil: Rubio, Gonzalo Daniel. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Misiones. Estacion Experimental Agropecuaria Cerro Azul.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Haddad, Charles R.. University of the Free State; Sudáfric

    A revision of the endemic South African spider genus Austrachelas, with its transfer to the Gallieniellidae (Arachnida: Araneae)

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    The endemic South African spider genus Austrachelas Lawrence, 1938 is revised. The type species, A. incertus Lawrence, 1938, and A. natalensis Lawrence, 1942, are redescribed, and their males described for the first time. Seven new species are described: A. bergi n. sp. (female only), A. kalaharinus n. sp. (male only), A. merwei n. sp. (both sexes), A. pondoensis n. sp. (both sexes), A. reavelli n. sp. (both sexes), A. sexoculata n. sp. (male only), and A. wassenaari n. sp. (both sexes). A cladistic analysis performed including Austrachelas and various species of the corinnid subfamilies Trachelinae, Castianeirinae, Corinninae and Phrurolithinae, and species from the Liocranidae, Gallieniellidae and Lamponidae, suggests that Austrachelas is currently misplaced. Its transfer to the Gallieniellidae is proposed.Fil: Haddad, Charles R.. University of the Free State; SudáfricaFil: Lyle, Robin. University of the Free State; SudáfricaFil: Bosselaers, Jan. Royal Museum for Central Africa; BélgicaFil: Ramirez, Martin Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

    Ground-dwelling spider assemblages in contrasting habitats in the central South African Grassland Biome

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    Background: Ground-dwelling spider assemblages in shrublands and cultivated pastures in the South African Grassland Biome have never been comprehensively studied. Objectives: Epigeic spiders were collected in eight different habitats in the Amanzi Private Game Reserve in the Free State to determine assemblages of different vegetation types. Methods: Three of the sampled habitats were contrasting low-lying shrublands; three were contrasting hill aspects (northern slope, southern slope and plateau) in the Buddleja saligna–Searsia burchellii–Olea europaea africana subcommunity; one habitat was cultivated Digitaria eriantha pastures, and the last habitat was an area in and around a freshwater dam. Spiders were sampled by pitfall trapping in early spring (Sept. 2012), mid-summer (Jan. 2013), mid-autumn (Apr. 2013) and mid-winter (July 2013). Results: A total of 2982 adult spiders were collected, representing 129 species and 33 families. Ammoxenidae was the most abundant family (40.85%), followed by Gnaphosidae (21.26%), Zodariidae (10.80%) and Salticidae (10.26%). Gnaphosidae was the most species-rich family (24.81%), followed by Salticidae (13.18%), Lycosidae (11.63%) and Zodariidae (6.20%). Spider activity densities and species richness did not differ significantly between habitats, although significant seasonal fluctuations were detected. The three hill aspects and cultivated D. eriantha pastures had the most distinct assemblages, while those of the three low-lying shrublands and freshwater dam showed considerable overlap. Conclusions: Our results indicate that the aspect of hills has a significant effect in shaping spider assemblages, while the vegetation composition of shrublands is not strongly influential. The unique spider assemblages of cultivated D. eriantha pastures can be attributed to the absence of woody plants. Conservation implications: This was the first study to investigate ground-dwelling spider assemblages in shrublands and cultivated pastures in the South African Grassland Biome. Our study confirms that hill aspects, shrublands and pastures harbour very different spider faunas. When identifying land for potential expansion or establishment of protected areas, conservation planners should ensure that the greatest diversity of vegetation units are included to optimise the conservation of biodiversity

    A new species of the spider genus Cangoderces (Araneae, Telemidae) from South Africa

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    A new species of the spider family Telemidae from South Africa, Cangoderces globosa sp. n., is diagnosed, described and illustrated. This is the second species of the family to be recorded from the country. Consistent with the habits of most Afrotropical telemids, C. globosa sp. n. was collected by sifting leaf litter in forests

    Diversity of non-acarine arachnids of the Ophathe Game Reserve, South Africa : testing a rapid sampling protocol

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    As part of the second phase of the South African National Survey of Arachnida (SANSA), field surveys were conducted in many degree-square grids throughout the country using a standardised rapid sampling protocol. This study reports on the arachnid diversity of the Ophathe Game Reserve (OGR) in northern KwaZulu-Natal, as found during a preliminary survey in June 2007 (mid winter) and a SANSA field survey in October 2008 (mid spring) in four representative habitats. The SANSA survey included seven sampling methods: pitfalls, beating, sweep-netting, litter sifting, hand collecting, night collecting and Winkler traps. A total of 282 species in six arachnid orders were collected during the two surveys, of which spiders were the most species-rich order (268 species in 47 families). The SANSA survey yielded 966 adult arachnids, representing six orders and 197 species, with a further 67 species represented only by immatures. Although adult arachnid abundance (n) differed considerably between the four habitats (range: 156–321), adult species richness (Sobs) was less variable (range: 65–85). These survey results are comparable with several longer-term surveys in the Savanna biome, and indicate that the SANSA sampling protocol can yield an impressive diversity of arachnids during a relatively short period of sampling, with a high level of coverage (> 0.8 for sites and most sampling methods) and moderate levels of sample completion for adults (> 0.55 for all sites), despite logistical and temporal challenges. Additional repetitions of the SANSA sampling protocol in other seasons will likely increase biodiversity knowledge of arachnids in OGR considerably. CONSERVATION IMPLICATIONS : The implementation of rapid sampling protocols in an atlas project is essential to generate a large volume of species-level data. The SANSA protocol is an efficient means for rapidly generating arachnid data, and in future will allow for an assessment of diversity patterns in degree-square grids across South Africa.http://www.koedoe.co.zaam201

    Spiders (Arachnida: Araneae) of the vegetation layer of the Mkambati Nature Reserve, Eastern Cape, South Africa

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    The Pondoland region of the Eastern Cape province, South Africa is very poorly studied with regard to invertebrate diversity, particularly in the case of arachnids. Accordingly, and in view of proposed infrastructural and mining developments in this ecologically sensitive area of high plant endemism, baseline data are provided on spiders (Araneae) of the vegetation layer (i.e. excluding the ground-dwelling fauna) of the Mkambati Nature Reserve (MNR). Spiders were collected at 26 sites (six forest and 20 grassland sites) in the MNR over an eight-day period, using sweep sampling and active searching of flowers in grassland and tree beating in forests, as part of a broader biodiversity survey. Additional specimens were collected with Malaise and pan traps. A total of 1275 specimens were sampled, representing 132 species (6.6% of the total number recorded in South Africa) in 103 genera and 29 families. Theridiidae and Araneidae were the most diverse spider families in the reserve, represented by 22 species each (16.7% of the total), followed by Thomisidae with 19 species (14.4%) and Salticidae with 18 species (13.6%). Grassland and forest had distinct spider faunas, with only 24.2% of species being recorded from both biomes. The average number of species sampled per site in grassland and forest was 26 species for both habitats, although values for the two biomes are not directly comparable because different sampling methods were used. All 132 species are new records for the reserve, of which 20 were new records for the Eastern Cape and at least eight spider species may be new to science. The spider diversity captured despite temporal and methodological limits indicates that many additional species are likely to occur in the reserve. CONSERVATION IMPLICATIONS: If the MNR is not adequately conserved at least five new species, which may be confined to the area, would be at high risk of extinction and 15 other species endemic to the Pondoland and KwaZulu-Natal region would have their risk of extinction increased.The Earthwatch Institute, Eastern Cape Nature Conservation and the National Research Foundation through a grant to M.H.http://www.koedoe.co.zaab201

    The future of the global food system

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    Although food prices in major world markets are at or near a historical low, there is increasing concern about food security—the ability of the world to provide healthy and environmentally sustainable diets for all its peoples. This article is an introduction to a collection of reviews whose authors were asked to explore the major drivers affecting the food system between now and 2050. A first set of papers explores the main factors affecting the demand for food (population growth, changes in consumption patterns, the effects on the food system of urbanization and the importance of understanding income distributions) with a second examining trends in future food supply (crops, livestock, fisheries and aquaculture, and ‘wild food’). A third set explores exogenous factors affecting the food system (climate change, competition for water, energy and land, and how agriculture depends on and provides ecosystem services), while the final set explores cross-cutting themes (food system economics, food wastage and links with health). Two of the clearest conclusions that emerge from the collected papers are that major advances in sustainable food production and availability can be achieved with the concerted application of current technologies (given sufficient political will), and the importance of investing in research sooner rather than later to enable the food system to cope with both known and unknown challenges in the coming decades

    Faunistic diversity of spiders (Arachinda: Araneae) of the Savanna Biome in South Africa

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    Invertebrates include more than 80% of all animals, yet they are severely under-represented in studies of southern African diversity. Site biodiversity estimates that ignore invertebrates, not only omit the greatest part of what they are attempting to measure, but also neglect major contributions 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 23 739 records from 1260 localities were recorded in the South African Savanna Biome until the end of 2010. This include 1230 species represented by 381 genera and 62 families. 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 summarised for all quarter-degree squares for 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 finer scales throughout the region, several areas have little information. The Salticidae is the most diverse family (162 spp.) and also has the most endemic savannah species (42 spp.). An 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. A rarity index for each species gives a preliminary indication of their conservation importance. Patterns of guild composition are summarised and species known to play a role as predators in agro-ecosystems found within the biome are also discussed.The Agricultural Research Council (ARC) and the South African National Biodiversity Institute (SANBI), Threatened Species Programme for funding the South African National Survey of Arachnida (SANSA) phase 2.http://www.tandfonline.com/loi/ttrs20ab201
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