A Study in Scarlet: Integrative Taxonomy of the Spider Genus Loureedia (Araneae: Eresidae)

Abstract

The eresid spider genus Loureedia (Miller et al., 2012) was described a decade ago, despite its type species being described in the mid-19th century, which illuminates the difficulties in obtaining specimens. The genus was initially described as monotypic. Ever since, four other species have been assigned to Loureedia, including three newly discovered ones. Primarily due to the extravagant appearance of the males, stories about the discovery of species of Loureedia have been the subject of relatively wide media coverage over the years, leading to numerous new populations and putative undescribed species being documented by naturalists and citizen scientists. These species, although bearing distinct differences in their coloration patterns, typically vary only slightly in the structure of their copulatory organs, the primary traits used in spider systematics. This highlights an important taxonomic problem: while it is easy to diagnose the genus or recognize the species that belong to it, it is challenging to differentiate the species from one another, particularly when using only a single line of evidence. In this paper, we have tackled this issue using an integrative approach, i.e., a combination of molecular markers (the mitochondrial COI) and traditional morphological characters. The effects of different observational angles on the perceived shape of the conductor are discussed. Except for one species, we obtained DNA data of all members of the genus. Based on these data, the first phylogeny for Loureedia is presented, and two North African species, Loureedia maroccana (Gál et al., 2017) and Loureedia jerbae (El-Hennawy, 2005), are revalidated from synonymy. The distribution records of all described species are mapped.