Master of Science / Division of Biology / David A. Haukos / The regal fritillary (Speyeria idalia) was once an abundant butterfly species of North American prairie communities. Despite its once broad geographic distribution, populations have declined by ~99% in the prairie region for reasons that are poorly understood. The rapid, range-wide declines and persistent threats to extant populations from habitat loss and mismanagement prompted the U.S. Fish and Wildlife Service to initiate a species status review of the regal fritillary as a potential candidate for listing under the endangered species act in September 2015. Due to the uncertain status and contention regarding the effects of management practices (i.e., burning, grazing, and haying) on regal fritillary, my research objectives were to assess the effects of management practices and habitat features on the distribution and density of regal fritillary and their preferred larval host plant for the Midwest, prairie violet (Viola pedatifida). I generated species distribution models (SDM) of prairie violet to readily identify potential areas across the landscape containing patches of host plants and subsequently facilitate the location of regal fritillary larvae. The SDM produced maps of the probabilistic occurrence distribution of prairie violet throughout my study area and highlighted habitat features and management practices important to the occurrence of prairie violet. The seven final variables used to create the SDM and identified as important to the occurrence of prairie violet were elevation, slope, hillshade, slope position, land cover type, soil type, and average fire frequency. Using the SDM for prairie violet, I located eight areas to conduct surveys for regal fritillary larvae that were managed using various management (grazing and haying) regimes and fire-return intervals (low ≥ 10 years, moderate 3-5 years, and high 1-2 years). I used a binomial generalized linear model to determine the effects of management, host plant density, months since burn, and the interaction between months since burn and management on the occurrence distribution of regal fritillary larvae. My results indicate that greater host plant density and short fire-return intervals are important to the occurrence of regal fritillary larvae and, despite current management recommendations, larvae may be negatively impacted by a lack of fire. Finally, I surveyed tracts of prairie with my study area using a distance sampling approach along line transects stratified by overall management (burned, grazed, and hayed) and fire-return interval (low ≥10 years, moderate 3-5 years, and high 1-2 years) for adult regal fritillary. My results indicated that adult density was at least 84% greater in areas that received moderate fire-return intervals and greatest in areas that were grazed and burned on a moderate fire-return interval. However, density estimates of adult regal fritillary did not differ among overall management practices (i.e., burned grazed, hayed). Additionally, adult density increased as percent cover of grass, litter, and prairie violets increased. In contrast, adult density decreased as percent cover of woody vegetation and forbs increased. These results support the use of prescribed fire in a shifting mosaic or patch-burning practice as a viable management strategy for maintaining and conserving regal fritillary populations within the Flint Hills region.

North American Speyeria butterflies are a group whose species hypotheses are confounded by shared wing color patterns between sympatric populations of closely related recognized species due to a putatively recent origin in evolutionary time. Previous studies of this group and the closely related Palearctic genus Argynnis , suggest that Speyeria is monophyletic but derived from within Argynnis . Sampling in these studies has either involved few basal Speyeria species, or too few Argynnis species (Simonsen 2006, Simonsen et al. 2006). Thus, no comprehensive phylogenetic analysis exists for all members that answers the question of monophyly of Speyeria , or other subgeneric taxa,and their relationship to Argynnis species. A phylogenetic analysis was completed of all North American Speyeria species and nearly all species within Argynnis , using one mitochondrial (CO1) and four nuclear genes (EF1?, WG, GAPDH, and RPS5). The results indicate that North American Speyeria is a monophyletic group, but that Palearctic Argynnis is paraphyletic. Three major lineages are identified within Argynnis sensu lato : two Palearctic and one containing both Palearctic and Nearctic species. Argynnis species representing the subgenera Argyreus , Argyronome , Childrena , Damora , Pandoriana , and Nephargynnis , belong to a well-supported lineage that split early in the evolution of the group and is comprised of species with long branches. Fabriciana and Mesoacidalia were both recovered as strongly supported lineages, except for A. clara which was recovered as sister to Speyeria . In summary, the phylogenetic analyses suggest the need for reorganization into three genera: Argynnis , Fabriciana , and Speyeria . The results have implications for the conservation of these butterflies across the temperate zone by providing a framework for understanding potential gene flow between sympatric species complexes, proper taxonomic validity, and the natural history of threatened populations of Speyeria and Argynnis butterflies.

Traditionally, methods for phylogenetic and phylogeographic inference have relied heavily on morphological data. Molecular data can provide an independent assessment of patterns and are particularly desirable when morphology may be under natural selection. Herein we present a phylogeographic analysis of the highly polytypic butterfly, Speyeria callippe. Samples were drawn from 71 populations across western North America. Phylogeographic trends are inferred from analysis of the gene Cytochrome oxidase subunit I ( CoI ). Patterns of mtDNA diversity imply historical panmixia and Mid-to-late Pliocene divergence from other Speyeria approximately xx mya. Diversification within the species appears to have occurred primarily during the Pleistocene. The data partially support a hypothesis of multiple waves of diversification following the climatic fluctuations of glacial and interglacial periods. Speyeria callippe was found to be paraphyletic containing both Speyeria egleis and Speyeria edwardsii. The genetic variation observed within S. callippe was highly structured reflecting local geography. However, this did not extend to larger scales as subspecies and major color pattern groups were not recovered as monophyletic, consistent with the large amount of overlapping morphological variation. Overall, intraspecies differentiation in morphology and mtDNA observed here indicate S. callippe is a young species complex with potentially adaptive color pattern variation that is in a relatively early stage of sorting into geographically separate entities.