<p>The tribe Edrotini is the largest component group of the largest tenebrionid subfamily, Pimeliinae, in the Americas, with 427 described species/subspecies in 55 genera. However, the group is taxonomically impeded, with the last comprehensive revision published nearly 115 years ago. This is particularly regrettable since members of this tribe are ubiquitous in arid regions throughout the Americas and are exceptionally diverse in their morphology and behaviors. To provide phylogenetic context and a foundation for taxonomic work, in Chapter 1 I sample a majority of genera and reconstruct the first phylogeny of the Edrotini, using targeted enrichment sequencing. My results indicate major changes are required to both edrotine tribal composition and generic concepts. In combination with a suite of eight morphological characters I use this phylogeny to reconstruct ancestral states and test for characters correlated with stridulation the tribe. I find stridulation is strongly correlated with two morphological characters and propose a defensive function for these structures</p> <p>In Chapter 2, I use the molecular phylogeny in combination with 100 morphological characters to evaluate all Edrotini genera and members of five related tribes with constrained parsimony analyses. Based on the results thirteen genera are transferred from the Edrotini and the tribal classification is revised, with 35 genera recognized and description of a further five recommended. One neotype and seven lectotypes are designated for type species. A dichotomous key to genera is provided. Thirty-one current genera are redescribed; two species described; and four genera described, including four species. One subgenus is elevated to genus and three genera are placed as subgenera pending a species-level revision of the clade. Six genera, four subgenera, and one species are synonymized. Eleven species are transferred to the correct genus and one replacement name proposed. </p> <p>And in Chapter 3, I revise the genus <em>Edrotes</em> LeConte to include eight species distributed across arid southwestern North America. All species are redescribed, of which three are brought out of synonymy. A neotype for <em>E. rotundus</em> (Say) is designated. The synonymic position of five species is amended. An illustrated key to <em>Edrotes</em> species is included. A molecular phylogeny of all species is generated and used to infer divergences dates and historical biogeography for the genus. The most recent common ancestor of <em>Edrotes</em> is dated to the late Miocene or early Pliocene and inferred to have inhabited the Sonoran Desert. </p>

<p dir="ltr">The lichen-feeding tiger moth tribe Lithosiini (Erebidae: Arctiinae) represent the largest radiation of invertebrate lichenivory. Caterpillars feed on lichen and as they feed, also sequester lichen polyphenolics, a behavior unique to these insects. The role of these compounds is believed to defend lithosiines against predators as larvae have been found to be protected against predators such as ants and moths to predators such as birds and bats. Experimental testing with controlled diets is necessary to fully make this connection, however little is known about host specifics for lithosiines. Furthermore, although lithosiines are monophyletic, the lack of a fully resolved phylogeny hampers investigation into many of the shallower level relationships, e.g. those among genera and species, within the group.</p><p dir="ltr">I addressed these knowledge gaps using the subtribe Cisthenina. Members of this group have been used to investigate predator-prey interactions and been included in morphological and molecular studies. Thus, while the group still needs attention, there is an ample amount of legacy loci data available for its members. I used these data to investigate the evolutionary relationships at the genus level, but to increase resolution in my analyses I additionally sampled taxa throughout the group with a recently developed anchored hybrid enrichment (AHE) probe set. I combined it with the legacy loci to both increase taxon sampling and resolution. I confirmed that trees made strictly from the legacy loci were unsuccessful and resulted in poorly supported relationships that made little sense. The addition of the AHE data greatly helped resolve relationships, however, there remained areas that were poorly supported and they appear to be genera with only a few loci. Thus, there is still room for improvement, but this offers a way for moving forward in lithosiine research, particularly to involve others who may have limited funding, equipment, and/or personnel and may only be able to afford legacy loci in diverse collaborations.</p><p dir="ltr">As the AHE probe set worked well with genus-level relationships I further attempted to use it in species delimitation of the notorious <i>Hypoprepia fucosa</i>-<i>miniata </i>species complex. Members of this group are varying shades of yellows, oranges and reds and have a convoluted taxonomic history. I gathered and organized over 4,000 specimens and using the AHE probe set found support for five distinct species. Interestingly, I used other morphological characters such as genitalia, but found no differences between species and a large amount of intraspecific variation. This suggests other courtship behaviors may be present and external morphology, i.e., color patterns, remain the best way to identify species. As part of this I am describing a new species and raising one from subspecies and as species are now readily distinguishable, they can be used for further investigations into lithosiines.</p><p dir="ltr">I used a member of this complex, <i>H</i>. <i>fucosa</i> to then evaluate the use of species distribution models (SDMs) to better understand their niche and how it relates to plausible lichen hosts. I evaluated 17 lichen species from two lichen genera, <i>Physcia </i>(13 species) and <i>Myelochro</i><i>a </i>(4 species)<i>. </i>These genera were selected based on previous feeding assays and the metabolites found in them have also been found in <i>H</i>. <i>fucosa </i>further suggesting caterpillars may feed on them. SDMs typically only use environmental factors to define and predict species niches. I compared the niches described by traditional SDMs to assess how similar they were, but I also investigated the use of lichens as biotic factors in the models. I assessed the influence each lichen had on the moth’s distribution found the niche of every lichen to be significantly different than that of the moth and their inclusion in SDMs of <i>H</i>. <i>fucosa </i>to improve model performance. This suggests <i>H</i>. <i>fucosa </i>caterpillars to be polyphagous, but to have some connection with these lichens. Further investigation with live specimens is needed, but these results support this as an effective way to describe lithosiine niches to better understand lichen feeding.</p>

<p>Eastern black walnut (<i>Juglans nigra</i> L.) ranks among the most highly valued timber species in the central hardwood forest and across the world. This valuable tree fills a critical role in native ecosystems as a mast bearing pioneer on mesic sites. Along with other <i>Juglans</i> spp. (Juglandaceae), <i>J. nigra</i> is threatened by thousand cankers disease (TCD), an insect-vectored disease first described in 2009. TCD is caused by the bark beetle <i>Pityophthorus juglandis</i> Blackman (Corthylini) and the phytopathogenic fungus <i>Geosmithia morbida</i> Kol. Free. Ut. & Tiss. (Bionectriaceae). Together, the <i>P. juglandis</i>-<i>G. morbida</i> complex has expanded from its historical range in southwest North America throughout the western United States (U.S.) and Europe. This range expansion has led to widespread mortality among naïve hosts <i>J. nigra</i> and <i>J. regia</i> planted outside their native distributions.</p> <p> The severity of TCD was previously observed to be highest in urban and plantation environments and outside of the host native range. Therefore, the objective of this work was to provide information on biotic and abiotic environmental factors that influence the severity and impact of TCD across the native and non-native range of <i>J. nigra</i> and across different climatic and management regimes. This knowledge would enable a better assessment of the risk posed by TCD and a basis for developing management activities that impart resilience to natural systems. Through a series of greenhouse-, laboratory- and field-based experiments, environmental factors that affect the pathogenicity and/or survival of <i>G. morbida</i> in <i>J. nigra</i> were identified, with a focus on the microbiome, climate, and opportunistic pathogens. A number of potentially important interactions among host, vector, pathogen and the rest of the holobiont of TCD were characterized. The <i>holobiont</i> is defined as the whole multitrophic community of organisms—including <i>J. nigra</i>, microinvertebrates, fungi and bacteria—that interact with one another and with the host.</p> <p>Our findings indicate that interactions among host, vector, pathogen, secondary pathogens, novel microbial communities, and novel abiotic environments modulate the severity of TCD in native, non-native, and managed and unmanaged contexts. Prevailing climatic conditions favor reproduction and spread of <i>G. morbida</i> in the western United States due to the effect of wood moisture content on fungal competition. The microbiome of soils, roots, and stems of trees and seedlings grown outside the host native range harbor distinct, lower-diversity communities of bacteria and fungi compared to the native range, including different communities of beneficial or pathogenic functional groups of fungi. The pathogen <i>G. morbida</i> was also associated with a distinct community of microbes in stems compared to <i>G. morbida</i>-negative trees. The soil microbiome from intensively-managed plantations facilitated positive feedback between <i>G. morbida</i> and a disease-promomting endophytic <i>Fusarium solani</i> species complex sp. in roots of <i>J. nigra</i> seedlings. Finally, the nematode species <i>Bursaphelenchus juglandis</i> associated with <i>P. juglandis</i> synergizes with <i>G. morbida</i> to cause foliar symptoms in seedlings in a shadehouse; conversely, experiments and observations indicated that the nematode species <i>Panagrolaimus</i> sp. and cf. <i>Ektaphelenchus</i> sp. could suppress WTB populations and/or TCD outbreaks.</p> <p>In conclusion, the composition, function, and interactions within the <i>P. juglandis</i> and <i>J. nigra</i> holobiont play important roles in the TCD pathosystem. Managers and conservationists should be aware that novel associations outside the host native range, or in monocultures, intensive nursery production, and urban and low-humidity environments may favor progression of the disease through the effects of associated phytobiomes, nematodes, and climatic conditions on disease etiology. Trees in higher diversity, less intensively managed growing environments within their native range may be more resilient to disease. Moreover, expatriated, susceptible host species (<i>i.e.</i>, <i>J. nigra</i>) growing in environments that are favorable to novel pests or pest complexes (<i>i.e.</i>, the western U.S.) may provide connectivity between emergent forest health threats (<i>i.e.</i>, TCD) and native host populations (<i>i.e.</i>, <i>J. nigra</i> in its native range).</p>