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...

Spiders (Arachnida: Araneae) of a wildlife and cattle savanna ranch in South-Western Zimbabwe

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Spiders (Arachnida: Araneae) of a wildlife and cattle savanna ranch in South-Western Zimbabwe

In order to contribute to spider diversity distribution records within Zimbabwe, spiders were sampled at a mixed wildlife and cattle ranch using pitfall traps and sweep-netting. Sampling was conducted from June 2017 to April 2018. A total of 2328 spiders representing 25 families, 94 genera, and 166 species were recorded. The most species-rich families were Salticidae (33 spp.), followed by the Gnaphosidae (28 spp.) and Lycosidae (20 spp.), while eight families were represented by a single species. Pitfall traps accounted for 1857 individuals overall, with the ground-dwelling fauna dominated by Stenaelurillus guttiger (37.86% of the total abundance). Sweep-nets accounted for 471 individuals overall, with the grass-dwelling fauna dominated by Thyene thyenioides (15.29% of the total abundance). The most abundant functional group was the free-living ground-dwellers (n = 1809, 77.71%), followed by free-living plant-dwellers (n = 266, 11.43%) and orb-web builders (n = 186,
7.98%). The current study contributes to the knowledge of a megadiverse group of predatory arthropods in the region.

Conservation implications: Sampling and monitoring of rangelands is essential, as the former aids in the identification of new species not previously recorded, as well as increasing knowledge on the distribution of spider species, which if not adequately conserved could face significant threats to their survival even before their documentation.

Sebata, Sicelo, Charles R. Haddad, Moira J. FitzPatrick, & Stefan H. Foord. "Spiders (Arachnida: Araneae) of a wildlife and cattle savanna ranch in South-Western Zimbabwe." Koedoe [Online], 65.1 (2023): 7 pages. Web. 12 Mar. 2024