Hypochilus is a relictual lineage of Nearctic spiders distributed disjunctly across the United States in three montane regions (California, southern Rocky Mountains, southern Appalachia). Phylogenetic resolution of species relationships in Hypochilus has been challenging, and conserved morphology coupled with extreme genetic divergence has led to uncertain species limits in some complexes. Here, Hypochilus interspecies relationships have been reconstructed and cryptic speciation more critically evaluated using a combination of ultraconserved elements, mitochondrial CO1 by-catch, and morphology. Phylogenomic data strongly support the monophyly of regional clades and support a ((California, Appalachia), southern Rocky Mountains) topology. In Appalachia, five species are resolved as four lineages (H. thorelli Marx, 1888 and H. coylei Platnick, 1987 are clearly sister taxa), but the interrelationships of these four lineages remain unresolved. The Appalachian species H. pococki Platnick, 1987 is recovered as monophyletic but is highly genetically structured at the nuclear level. While algorithmic analyses of nuclear data indicate many species (e.g., all H. pococki populations as species), male morphology instead reveals striking stasis. Within the California clade, nuclear and mitochondrial lineages of H. petrunkevitchi Gertsch, 1958 correspond directly to drainage basins of the southern Sierra Nevada, with H. bernardino Catley, 1994 nested within H. petrunkevitchi and sister to the southernmost basin populations. Combining nuclear, mitochondrial, geographical, and morphological evidence a new species from the Tule River and Cedar Creek drainages is described, Hypochilus xomotesp. nov. We also emphasize the conservation issues that face several microendemic, habitat-specialized species in this remarkable genus.

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Charaxes mtuiae Collins Congdon and Bampton, 2017 was discovered in 2005 in the Udzungwa Mountains of Tanzania, where the caterpillars feed exclusively on Diospyros natalensis. This study was aimed at determining the abundance and spatial distribution of C. mtuiae and its host plant, as well as its evolutionary history. Field surveys were conducted between April 2017 and December 2018. Stems of the host plant were counted in sampling plots and their diameter at breast height measured, and categorised as mature if the diameter was ≥ 12 cm, otherwise as recruits. Charaxes mtuiae was sampled by searching for immatures on the leaves of the host plant and capturing adults using traps. DNA material of C. mtuiae was extracted, sequenced, and aligned with 63 other species of Charaxes. A total of 1,173 stems of the host plant including 1,064 recruits and 102 mature stems were recorded. One specimen of C. mtuiae found at caterpillar stage was raised to adulthood, and three empty pupa cases of C. mtuiae were recorded. The phylogenetic relationship of C. mtuiae and its sister lineages was concordant with previous descriptions, based on morphology. Our results indicate that C. mtuiae is rare, despite the high abundance of its host plant. Continued research and monitoring of C. mtuiae population to understand its ecological requirements; and expansion of surveys into other parts of the country where the host plant occurs to establish its distribution country-wide are recommended.

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