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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Phylogenetic Relationships of Genera in the Caddisfly Family Limnephilidae Using Anchored Hybrid Enrichment-based Phylogenomic Analysis (Insecta:Trichoptera)

Rawlinson, Kyle Charles 23 November 2021 (has links)
Limnephilidae is a large family within Trichoptera, consisting of 4 subfamilies (Dicosmoecinae, Ecclisomyiinae, Limnephilinae, and Philocascinae), 98 genera, and 1178 species. It is among the most diverse families within Trichoptera. It is also ecologically diverse, occupying more habitats than any other family in the order. There are currently no published generic phylogenies of Limnephilidae based on molecular data. Here we used anchored hybrid enrichment to capture and sequence 922 loci for 57 species taken from what have been considered the full range of genera in the family. We expanded the taxon sampling by adding supplementary species with DNA barcodes, 28S sequences, or containing both from other sources. We present a favored tree from the collected data. We examine the evolutionary patterns associated with larval habitat transitions and highlight instances where our preferred evolutionary tree is incongruent with current limnephilid classification.
2

Evolutionary Studies of Fruit-Piercing Moths in the Genus Eudocima Billberg (Lepidoptera: Erebidae)

Crystal Klem (7053191) 16 October 2019 (has links)
<p>The prevalence of monoculture and landscape simplification is correlated with diminished biodiversity and increased presence of harmful pest species in crop environments. Lepidoptera is the largest clade of herbivorous insects, with many agriculturally significant species. The pest status of insects in agricultural settings is human-defined based on behaviors that may negatively impact the yield of susceptible crops. As such, both the insect behavior and the affected crop play a part in determining pest status. One helpful means of understanding pest status involves using pest injury guilds, which distinguish different pest groups based on similar kinds of injury to comparable plant tissues. Pest injury guilds defined in the literature are reviewed and then applied to agriculturally-significant Lepidoptera. Specialized Lepidoptera behaviors are reviewed within their respective injury guilds, and the systematics, ecology, and control options for fruit-piercing moths are discussed within the context of pest Lepidoptera behaviors. To address the need for distribution information for economically relevant Lepidoptera, the first annotated checklist of pest Lepidoptera is also provided for the United States and Canada. This checklist includes 80 agriculturally significant Lepidoptera species and complexes, and incorporates notes on distribution, species delimitation, natural history, and establishment.<br></p> <p><b> </b></p> <p>Fruit-piercing moths in the genus <i>Eudocima</i> Billberg, 1820 have significant pest status as adults rather than as larvae, and directly injure fruits using a specially-adapted proboscis. There are at least 48 <i>Eudocima</i> species which are found in the world’s tropics, but confusion persists in the classification of this genus and there are several suspected complexes. Additionally, the area of origin for this group is uncertain, although the Oriental region has been postulated. A comprehensive phylogenetic analysis of <i>Eudocima</i> is conducted using 82 morphological characters, which are each described and figured, and analyzed using parsimony. Results suggest that <i>Eudocima</i> is not monophyletic. Strongly-resolved relationships were recovered, although these did not correspond with previous generic concepts. The Australian region is recovered as the most parsimonious area of origin for <i>Eudocima</i>, and patterns of dispersal, particularly between the Oriental and Australian regions along the Indo-Australian Archipelago, are discussed.</p> <p> </p> <p>The <i>Eudocima phalonia</i>-complex is distributed throughout the Old World and has been the subject of increasing interest and research due to its economic impact in the tropics and status as a potential invasive species. The recent description of closely-related sister species, as well as morphological variation documented within <i>E. phalonia</i> itself, suggests possible speciation occurring within <i>E. phalonia</i> populations across its wide geographic range. To test species boundaries for this taxon, a molecular phylogeny is constructed using anchored hybrid enrichment and a next-generation sequencing approach. Sampling for this phylogeny was informed using a global range map for <i>E. phalonia</i>, which was developed using georeferenced specimen data from natural history collections. Biogeographic analyses are also conducted to investigate the area of origin and dispersal patterns of <i>E. phalonia</i>, and to examine possible speciation modes and gene flow. Georeferenced range information is also utilized along with environmental variables in constructing a correlative environmental niche model using MaxEnt, which is used to evaluate a previous mini risk assessment for environmental suitability in the continental United States for <i>E. phalonia</i> establishment. Results suggest that <i>E. phalonia</i> is monophyletic, with gene flow still occurring between populations. The area of origin for <i>E. phalonia</i> is postulated to be the Oriental region, although further investigation is needed. Range predictions for <i>E. phalonia</i> from environmental modelling were performed for both the Old World, which concurred well with occurrence data, and for the New World. Assessment of environmental suitability for <i>E. phalonia</i> in the continental United States suggests areas in Florida and along the Gulf Coast are most favorable for establishment.</p>
3

<b>Phylogenomics and species distribution models to infer evolutionary relationships, delimit species, and better understand lichen-host interactions in tiger moths</b>

Makani L Fisher (17656290) 16 December 2023 (has links)
<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>

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