New Insight Into the Evolutionary Arms Race Between Spider Egg Sac Pseudoparasitoids and Active Maternal Care by the Spiders

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  New Insight Into the Evolutionary Arms Race Between Spider Egg Sac Pseudoparasitoids and Active Maternal Care by the Spiders ABSTRACT Pseudoparasitoids can lead to high mortality in spider egg sacs, and in some cases, they reduce the reproductive success of a spider female to zero. On the other hand, a species that develops within the spider's egg sac uses a limited resource derived from a single egg sac for its larval development. Therefore, the most crucial behaviour that increases the fitness of free-living pseudoparasitoid females is choosing the best host for their offspring. We analysed various points of the counter-adaptations of the spider egg sac pseudoparasitoid and spiders exhibiting active maternal care, utilising the ichneumonid  Hidryta fusiventris  (Thomson, 1873) and the wolf spider  Pardosa lugubris  (Walckenaer, 1802). We showed that the oviposition decision of  H. fusiventris  is based on the spider's egg sac size and that the fema...

The faunistic diversity of spiders (Arachnida: Araneae) of the South African Cape Floristic Kingdom

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The faunistic diversity of spiders (Arachnida: Araneae) of the South African Cape Floristic Kingdom


Abstract

Spider species distribution in the Cape Floristic Kingdom (CFK) was compiled as part of the South African National Survey of Arachnida (SANSA), whose main aim was to create a relational database for the country’s arachnid fauna. Data from the CFK was extracted from taxonomic and faunistic published papers, as well as unpublished faunistic survey data in national collections. A total of 11 500 records from 130 localities were recorded in the CFK until the end of 2023, representing 62 families, 334 genera and 960 species, with two further families (Synotaxidae and Theridiosomatidae) only known from undescribed species. This represents 42.4% of the total spider fauna of South Africa. For each species, the global and CFK distribution, as well as the level of endemicity and a conservation assessment using the IUCN Red List criteria, are provided. A total of 269 spp. (28.0%) are endemic to the CFK, 49 spp. (5.1%) are of special concern, and 229 spp. (23.9%) are Data Deficient. However, most of the species (682 spp., 71.0%) have a wide distribution with no known threats and are categorised as Least Concern. Salticidae is the most species-rich family (128 spp.), with 30 spp. endemic to the CFK, followed by the Gnaphosidae (107 spp.), Thomisidae (86 spp.) and Lycosidae (49 spp.), while six families are represented by a single species. The last decade has seen an exponential growth in the knowledge of spiders in South Africa, and there are certainly many more species that must still be discovered and described.

A. S. Dippenaar-Schoeman, C. R. Haddad, S. H. Foord & L. N. Lotz (2024) The faunistic diversity of spiders (Arachnida: Araneae) of the South African Cape Floristic Kingdom, Transactions of the Royal Society of South Africa, DOI: 10.1080/0035919X.2024.2324912