Haplodiploid Hymenoptera females control the sex of their progeny, and their sex allocation is influenced by several factors. The impact of intra- and interspecific competition and of inbreeding and outbreeding on sex allocation has been studied in some species of the egg parasitoid Trichogramma. The pre-mating dispersion has also been studied. Impact of competition on sex allocation was observed for Trichogramma minutum Riley and Trichogramma pintoi Voegele. These species were chosen because of the ease with which than can be distinguish. Results show that females of both species lay more males under intraspecific competition than alone, following the Local Mate Competition theory, while only T. pintoi modifies its sex ratio under interspecific competition. Multiparasitism and natural habitat could explain this shift in the sex ratio. Trichogramma minutum, T. pintoi and Trichogramma evanescens Westwood pre-mating dispersion show that most matings occur at the emergence site. However, the three species have a potential for off-patch mating, allowing genetic exchange between sub-populations. These three species were chosen because they are classified in different groups in the genus. Finally, T. evanescens did not modify its sex ratio following inbreeding or outbreeding. The incapacity to discriminate between kin and non-kin, insufficient genetic distance in outbreeding, or the population structure could explain these results.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.19695 |
| Date | January 2003 |
| Creators | Martel, Véronique |
| Publisher | McGill University |
| 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 | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Natural Resource Sciences) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002022780, Theses scanned by McGill Library. |
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