Aim: The genus Stasimopus is endemic to South Africa but has never undergone a phylogeographic review. This study aims to unravel the phylogeographic patterns and history of the many Stasimopus species which occur in the greater Karoo region. Location: The Karoo region, South Africa Time period: 2017-2018 Major taxa studied: Cork-lid trapdoor spider, Stasimopus (15 species). Methods: A fossil-calibrated phylogeny was produced based on three gene regions (CO1, 16S and EF-1ɣ) for Stasimopus specimens collected in the Karoo region, to infer dates of origin and diversification. Demographic analyses were performed on species with sufficient sample sizes (>4). Haplotype networks were constructed for each gene region and plotted on a map to infer phylogeographic patterns. Lastly, Mantel tests were performed to test for isolation by distance. Results: It was found that 15 species occur in the Karoo and that the genus radiation in the area is in the early Paleocene. Most diversification occurred between the late Eocene and the Miocene. Several species show signals of demographic expansions. Isolation by distance was detected, but only with a slight correlation. Main conclusions: It is apparent that aridification has played a vital role in the diversification of the genus in the Karoo region. This is a shared biogeographic influence between the mygalomorph fauna of the Karoo and arid region of western Australia. Stasimopus has radiated from the late Eocene and through the Miocene resulting in 15 extant species in the region. The Tankwa Karoo has been identified as a possible Pleistocene glacial cycle refugia for the species S. leipoldti. Many of the species in the Karoo are short range endemics, making them of high conservation concern. This study provided vital information as the Karoo is undergoing further desertification due to factors such as climate change, which may affect the future of short-range endemic spiders.

An important consequence of the discontinuous distribution of insect populations within their geographic range is phenotypic divergence. Detection of this divergence can be challenging when it occurs through subtle shifts in morphological traits with complex geometries, such as insect wing venation. Here, we used landmark-based wing geometric morphometrics to investigate the population-level phenotypic variation of the two subspecies of Glossina morsitans, G. m. centralis Machado and G. m. morsitans Westwood that occur in Zambia. Twelve homologous landmarks digitized on the right wings of 720 specimens collected from four and five sites (80 per site with 1:1 sex ratio) within the G. m. centralis and G. m. morsitans range respectively, were subjected to generalised Procrustes analysis to obtain wing centroid size (CS) and wing shape variable. Linear permutation models were then used to compare CS and wing shape between male and female G. morsitans, the two subspecies G. m. centralis and G. m. morsitans, and between sample locations within each subspecies range. Significant differences in CS and wing shape were observed between G. morsitans sexes, subspecies and sample locations within each subspecies range. Neighbour-joining trees derived from the analysis of Procrustes distances showed that tsetse within each subspecies range were highly divergent. We conclude that G. morsitans populations in Zambia exhibit significant population-level variation in fly size and wing shape which suggests high levels of population structuring. The main drivers of this structuring could be adaptation to local climatic condition, especially temperature and random genetic drift. We therefore recommend molecular studies to estimate the levels of gene flow between these populations and determine their levels of genetic isolation.