Systematic revision of the Savignia genus group (Araneae: Linyphiidae: Erigoninae) with notes on their cephalic lobe evolution

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  Systematic revision of the Savignia genus group (Araneae: Linyphiidae: Erigoninae) with notes on their cephalic lobe evolution Abstract The Savignia genus group includes nine morphologically complex yet similar genera where species were assigned based mainly on the cephalic lobes. Among these genera, males of Diplocephalus Bertkau, 1883, Savignia Blackwall, 1833 and Araeoncus Simon, 1884 show some of the most extraordinary cephalic lobes among dwarf spiders (Linyphiidae, Erigoninae). In this study we undertake the first phylogenetic analysis of the Savignia genus group. We use 269 morphological characters (175 newly defined) and 70 taxa (59 ingroup taxa) to reconstruct the relationships and evolutionary trends of cephalic lobes in this lineage. Our findings show that cephalic lobes with varying shapes and sizes appear in several Savignia genus group lineages, highlighting that it is not a good diagnostic character. The high support in several clades allows the redefinition of t...

FIRST RECORD OF RED-BACK SPIDER FAMILY THERIDIIDAE AND SPECIES LATRODECTUS HASSELTI (THORELL, 1870) (ARANEAE: ARACHNIDA) FROM DISTRICT GWADAR BALOCHISTAN, PAKISTAN

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FIRST RECORD OF RED-BACK SPIDER FAMILY THERIDIIDAE AND SPECIES LATRODECTUS HASSELTI (THORELL, 1870) (ARANEAE: ARACHNIDA) FROM DISTRICT GWADAR BALOCHISTAN, PAKISTAN

Abstract

Latrodectus hasselti (red back spiders) species belong to family theridiidae this was first reported by Thorell, 1870 from tropical and sub-tropical regions. The red back spider (Latrodectus hasselti), is a very poisonous species of spider. This species is well designated by their distinctive morphological structures and their male and female distinguish morphology. Morphometric features support vital discernments to its physical features, for identifications of the particular species, their behavioral and environmental analysis. Females of this species are significantly bigger than their males, usual body measurements of 25-17 mm, paralleled to 12-10 mm of males. Female of this species are described by the spherical abdomen, having protruding red stripes on dorsal part, whereas males frequently show bright color stripes. Leg sizes expose a distinctive leg formula which is IV > I > II > III, imitating for their prey capturing and web production. The Pedi palps of the males are extremely focused for their mating purpose and are divergent structurally in their structure from the females. Their morphometric qualities sustenance spider’s for reproductive process and their predatory approaches. Advance studies participating morphometric approaches which can boost up our understanding about the red back spider's compliance and population dynamics through various habitations. This species also first time recorded from district Gwadar Balochistan, Pakistan. This research work is based on ecology and morphometric of Latrodectus hasselti species (Thorell 1870) from Gwadar Balochistan Pakistan.

Insaf Ali Proffesor, Dr Tahira Jabeen Ursani and Jawaid A Khokhar (2024) “FIRST RECORD OF RED-BACK SPIDER FAMILY THERIDIIDAE AND SPECIES LATRODECTUS HASSELTI (THORELL, 1870) (ARANEAE: ARACHNIDA) FROM DISTRICT GWADAR BALOCHISTAN, PAKISTAN”, Policy Research Journal, 2(4), pp. 1359–1365. 

Available at: https://policyresearchjournal.com/index.php/1/article/view/180 (Accessed: 9 December 2024).