Revision, molecular phylogeny and biology of the spider genus Micaria Westring, 1851 (Araneae: Gnaphosidae) in the Afrotropical Region
The genus Micaria Westring, 1851 (Araneae, Gnaphosidae) is a group of small (1.85 - 5 mm) ant-like spiders that can be distinguished from other gnaphosids by their piriform gland spigots that are similar in size to the major ampullate gland spigots. According to the World Spider Catalog, there are 105 species of Micaria in the world, of which only four species are known from the Afrotropical Region, namely M. chrysis (Simon, 1910), M. tersissima Simon, 1910,M. beaufortia (Tucker, 1923) and M. ignea (O. PickardCambridge, 1872). The objectives of this study were to revise Micaria in the Afrotropical Region, providing new and updated records for each of the species, evaluating the relationships between them using COI barcoding data, and providing information on their biology, mimetic relationships and feeding ecology. These objectives were met by collecting fresh material from the KwaZulu-Natal, Western Cape, Northern Cape, and Free State provinces in South Africa. Fresh material of M. tersissima and M. chrysis were collected from their type localities, Komaggas and Port Nolloth (Northern Cape Province), respectively, for identification and DNA analyses. Material from eight collections yielded a variety of species of Micaria from countries throughout the Afrotropical Region. Male and female genitalia were dissected and cleaned using a pancreatin solution. The left leg II of male and female representatives of each species was preserved in absolute ethanol and sent to the Canadian Centre for DNA Barcoding (CCDB) for DNA barcoding (COI gene). The data were aligned using Mega X software and molecular analyses were performed using MrBayes for Bayesian Inference (BI) and RaxML for maximum likelihood (ML) analyses. Morphological analysis of the collected and voucher material yielded 17 new species for the Afrotropical Region, namely M. basaliducta sp. nov., M. bimaculata sp. nov., M. bispicula sp. nov., M. durbana sp. nov., M. felix sp. nov., M. gagnoa sp. nov., M. koingaas sp. nov., M. latia sp. nov., M. laxa sp. nov., M. medispina sp. nov., M. parvotibialis sp. nov., M. plana sp. nov., M. quadrata sp. nov., M. quinquemaculosa sp. nov., M. rivo sp. nov., M. salta sp. nov. and M. scutellata sp. nov. The maximum likelihood analysis recovered Micaria (sensu lato) as monophyletic and the subopaca group as paraphyletic, sharing a clade with M. aenea Thorell, 1871, M. longipes Emerton, 1890 and M. alpina (L. Koch, 1872). The pulicaria species group was recovered as polyphyletic in both the BI and ML analyses. Four Afrotropical species were recovered sister to M. formicaria (Sundevall, 1831) and may possibly form a new clade with the M. rossica / M. foxi group. Twenty feeding trials using Collembola, Hemiptera, Blattodea and Hymenoptera on a combination of sub-adult and adult M. beaufortia individuals show that 40% (n=8) and 45% (n=9) of Collembola and Hemiptera prey items were accepted. The results were considerably lower for Blattodea (5%, n=1) and Hymenoptera (0%, n=0) prey items. The potential ant (Hymenoptera: Formicidae) models of four Micaria species were identified and are as follows: M. beaufortia is a mimic of Anoplolepis custodiens F. Smith, 1858 (Formicinae) ants; Lepisiota (Formicinae) ants could potentially be the model of M. quinquemaculosa sp. nov. and M. chrysis; M. felix sp. nov. is potentially a mimic of Monomorium spp. (Myrmecinae) ants. In conclusion, this study was the first to revise the genus Micaria for the Afrotropical Region and resulted in the description of 17 new species, bringing the total for the region to 20 species. Nine of these species now have COI barcoding data uploaded to the Barcode of Life Data Systems (BOLD).