Population genetics prior to biological control: Ceutorhynchus weevils proposed for managing garlic mustard

I studied the population genetic structure of three weevil species, Ceutorhynchus alliariae, C. roberti, and C. scrobicollis, being considered for the biological control of garlic mustard, Alliaria petiolata, in North America. My first objective was to develop a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay which could be used to identify the morphologically indistinguishable larvae. This assay was developed for use in the analysis of population genetic structure of the three species and to aid scientists in evaluating host-specificity test results where larval development was incomplete or adults failed to emerge. The resulting assay provides a fast and inexpensive means of identifying otherwise indistinguishable larvae. My second objective was to study the population genetic structure of C. scrobicollis, to evaluate whether the areas where individuals were being collected for host-specificity testing consisted of one or more populations, to estimate the numbers of individuals needed during host-specificity testing and later introduction to adequately represent the diversity of the population, and to evaluate dispersal potential. Results suggest that C. scrobicollis in the area of Berlin, Germany constitute a network of subpopulations with low but significant differentiation among sites and movement of individuals between sites. I estimated that the number of individuals that would need to be sampled to capture 90% or 99% of the genetic diversity in the Berlin area was 10 and 27, respectively. The estimated average dispersal distance based on assignment tests for C. scrobicollis was 28 km. My third objective was to compare the differences in population genetic structure between C. alliariae and C. roberti to determine whether differences in genetic diversity or dispersal potential might aid in prioritizing one species over the other. These two species have similar life histories, distributions, and effects on garlic mustard. Results showed that, over a comparable region in central Europe, total gene diversity was significantly higher in C. roberti, though the difference between the two species was relatively small. Assignment tests suggest there is substantial gene flow among sites for both species. Overall, the results were similar for both species, and I recommend prioritizing based on biological or methodological attributes.

Name thesis:degree_name

Doctor of Philosophy (Ph.D.)

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Bioagricultural Sciences and Pest Management

Grantor dc:publisher

Colorado State University. Libraries

Year dc:date.issued

2009

Authors dc:creator

• Rauth, Steven J., author
• Hufbauer, Ruth, advisor

• Alliaria petiolata
• biological control
• Ceutorhynchus
• garlic mustard
• invasive species
• weevils
• entomology
• genetics

Statement dc:rights

• Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.

Language dc:language.iso

eng, English

Identifier URI

https://doi.org/10.25675/3.018289

OAI identifier oai:identifier

oai:mountainscholar.org:10217/237919