A species threshold was used to assign unidentified Hymenoptera into DNA barcode Operational Taxa (DbOT) for both an assessment of species richness in rose gall communities and as part of a broad scale survey of genome size diversity. The species threshold of 2.2% was calculated from minimum interspecific divergence of DNA barcode (COI, mtDNA) and internal transcribed spacer region 1 (ITS1, rDNA) sequences from both identified and unidentified Hymenoptera associated with rose galls induced by Diplolepis (Cynipidae). Analysis of both DNA barcodes and ITS1 sequences suggested that several described species of Diplolepis (Cynipidae), Periclistus (Cynipidae), and Torymus (Torymidae) require re-examination to define species boundaries. It was also determined that the total number of DbOTs is higher than previous estimates of species richness of Hymenoptera associated with rose galls induced by Diplolepis. Additionally, genome size estimations were determined for 51 DbOTs from all eight families of Hymenoptera associated with rose galls induced by Diplolepis, five of which did not have any previous genome size estimates. A subsequent large-scale survey of Hymenoptera enabled by the use of the DbOT approach produced genome size estimations for 309 DbOTs from 36 families in 13 superfamilies. It was shown that Hymenoptera do not have smaller genome sizes than other holometabolous orders, and that a parasitoid lifestyle does not appear to constrain genome size. The suggested positive relationship between genome size and development time was investigated by comparing mean genome size of taxa with known or apparent differences in development rate. It was concluded that statistical comparisons between taxa that are grouped in broad categories would be unlikely to detect significant differences in mean genome size because the range of biological features within such categories is highly variable. However, comparisons between interacting groups with narrowly defined development strategies determined that mean genome size was statistically smaller in taxa that obtained resources within a narrow window of opportunity. This result suggests that rapid development in relation to competitors may be important in species of Hymenoptera with higher mortality risk.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OGU.10214/3962 |
| Date | 11 September 2012 |
| Creators | Lima, João |
| Contributors | Gregory, T. R., Hanner, R. H., Shorthouse, J. D. |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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