Purdue University Graduate School
Wirth Dissertation.pdf (35.15 MB)


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posted on 2022-04-28, 01:17 authored by Christopher Charles WirthChristopher Charles Wirth

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

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. 

And in Chapter 3, I revise the genus Edrotes 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 E. rotundus (Say) is designated. The synonymic position of five species is amended. An illustrated key to Edrotes 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 Edrotes is dated to the late Miocene or early Pliocene and inferred to have inhabited the Sonoran Desert. 


Degree Type

  • Doctor of Philosophy


  • Entomology

Campus location

  • West Lafayette

Advisor/Supervisor/Committee Chair

Aaron D. Smith

Additional Committee Member 2

Ximena Bernal

Additional Committee Member 3

Stephen Cameron

Additional Committee Member 4

Brock Harpur