Phylogeny, evolution and speciation of Choristoneura and Tortricidae (Lepidoptera)

  • Author / Creator
    Fagua Gonzalez, Giovanny
  • Leafrollers moths are one of the most ecologically and economically important groups of herbivorous insects. These Lepidoptera are an ideal model for exploring the drivers that modulate the processes of diversification over time. This thesis analyzes the evolution of Choristoneura Lederer, a well known genus because of its pest species, in the general context of the evolution of Tortricidae. It takes an inductive view, starting with analysis of phylogenetic, biogeographic and diversification processes in the family Tortricidae, which gives context for studying these processes in the genus Choristoneura. Tectonic dynamics and niche availability play intertwined roles in determining patterns of diversification; such drivers explain the current distribution of many clades, whereas events like the rise of angiosperms can have more specific impacts, such as on the diversification rates of herbivores. Tortricidae are a diverse group suited for testing the effects of these determinants on the diversification of herbivorous clades. To estimate ancestral areas and diversification patterns in Tortricidae, a complete tribal-level dated tree was inferred using molecular markers and calibrated using fossil constraints. The time-calibrated phylogeny estimated that Tortricidae diverged ca. 120 million years ago (Mya) and diversified ca. 97 Mya, a timeframe synchronous with the rise of angiosperms in the Early-Mid Cretaceous. Ancestral areas analysis supports a Gondwanan origin of Tortricidae in the South American plate. Analysis detected an increase in speciation rate that coincided with the peak of angiosperm diversification in the Cretaceous, which was probably further heightened by continental colonization of the Paleotropics near the end of the Late Cretaceous. Taking advantage of the usefulness of mitogenomes as markers for phylogenetic studies across a range of taxonomic levels, a second part of the thesis focused on mitogenome variation across Choristoneura and particularly the spruce budworm Choristoneura fumiferana (Clemens) species complex, a notorious pest group of North American conifer forests. Phylogenetic relationships of Tortricidae were analyzed using 21 mitogenomes, including six newly-sequenced haplotypes in the spruce budworm complex, mitogenomes for three additional Choristoneura species, and 12 published mitogenomes. Phylogenetic informativeness of the mitogenome was evaluated by comparing its accuracy for recovering clades reconstructed in the previous chapter using different markers (nuclear genes) and the barcode fragment, and a time-calibrated tree was reconstructed using mitochondrial genes and fossil calibrations. Analysis of all protein-coding plus ribosomal genes together provided an efficient marker for reconstructing phylogenies at any taxonomic rank. The time-calibrated phylogeny showed evolutionary convergence of conifer feeding within Choristoneura, with the Nearctic spruce budworm complex and the Palearctic species Choristoneura murinana (Hübner) shifting onto conifers during the late Miocene from angiosperms after the expansion of boreal forest. Haplotype diversification within the spruce budworm complex was estimated at 3.5 Mya, and may be linked to the initial cooling cycles of the Northern Hemisphere in the Pliocene. Using the ages estimated in the previous chapters, I then focused on the genus Choristoneura, which is part of the species-rich tribe Archipini. Delimitation of Choristoneura has remained unresolved and taxonomic confusion has been generated by the transfer of Archips occidentalis (Walsingham) to Choristoneura, creating a homonym with Choristoneura occidentalis Freeman, an important defoliator of Nearctic forests. To define the limits of the genus, I reconstructed a phylogeny using published and new gene sequences of mitochondrial COI and ribosomal 28S for 23 species of Choristoneura, complemented by a large sample of outgroups. I also generated a time-calibrated tree using fossil and secondary calibrations to infer biogeographic and diversification processes in Choristoneura. The analysis recovered the genus as paraphyletic, with the tropical and subtropical species Archips occidentalis and Choristoneura simonyi (Rebel) and the Palearctic species Choristoneura evanidana (Kennel) excluded from the stem of genus. Consequently, Choristoneura is restricted primarily to species with a northern hemisphere distribution. An analysis of ancestral areas supported a Holarctic origin of Choristoneura about 23 Mya, followed by early colonization of the Palearctic. The main diversification occurred at the crown (16 Ma) when two clades diverged, one Nearctic and another mostly Palearctic. Cladogenesis was almost synchronous and related to herbivorous specialization, with each clade divided into coniferophagous or polyphagous lineages. The analyses support nomenclatural changes including transfers of Cudonigera houstonana Grote to Choristoneura; Archips occidentalis Walsingham to Cacoecimorpha Obraztsov; Choristoneura evanidana to Archips Hübner; and Choristoneura simonyi to Xenotemna Powell.

  • Subjects / Keywords
  • Graduation date
    Fall 2017
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
  • Specialization
    • Systematics and Evolution
  • Supervisor / co-supervisor and their department(s)
  • Examining committee members and their departments
    • Marcus, Jeffrey M. (Department of Biological Sciences, Faculty of Science, University of Manitoba)
    • Stothard, Paul (Department of Agricultural, Food and Nutritional Science)
    • Hall, Jocelyn (Department of Biological Sciences)
    • Evenden, Maya (Department of Biological Sciences)
    • Paszkowski, Cindy (Department of Biological Sciences)