Transgenerational Fecundity Compensation And Post-Parasitism Reproduction By Aphids In Response To Their Parasitoids
2017-03
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
Transgenerational Fecundity Compensation And Post-Parasitism Reproduction By Aphids In Response To Their Parasitoids
Authors
Published Date
2017-03
Publisher
Type
Thesis or Dissertation
Abstract
Increased reproductive effort by organisms in response to attack by consumers (‘fecundity compensation’) is well documented in both plants and animals, though most examples only involve direct compensation by the individuals exposed to consumers. In Chapter 1, I used the parasitoid wasp Lysiphlebus orientalis Starý & Rakhshani (Hymenoptera: Braconidae) and the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), to determine whether reproduction by parasitized aphids can lead to fecundity compensation. Although parasitism by L. orientalis strongly decreased fecundity for parasitized aphids, offspring of parasitized aphids reproduced at a greater rate at maturity than did the offspring of non-parasitized aphids. Also, parasitized aphids contained fewer but larger embryos developing within them. The presence of these larger embryos may explain how the offspring of parasitized aphids can produce more progeny with no apparent reduction in progeny quality. Mature and nearly mature A. glycines successfully reproduced after parasitism, a prerequisite for transgenerational fecundity compensation, and L. orientalis showed a preference for these age classes of aphids as hosts when foraging. This work is the first known demonstration of transgenerational fecundity compensation in an animal. In Chapter 2, I demonstrated that L. orientalis is able to suppress caged populations of A. glycines in spite of transgenerational fecundity compensation by parasitized aphids. Aphid populations exposed to parasitoids were driven to extinction within, on average, 8 or 11 weeks depending on the starting density of parasitoids. I also showed that transgenerational fecundity compensation has a relatively minor impact on modeled A. glycines populations. Instead, direct reproduction by parasitized aphids, as well as parasitoid host-stage preference, had stronger impacts. Finally, in Chapter 3, I showed that transgenerational fecundity compensation is not limited to the A. glycines – L. orientalis association, as it also occurs when Aphis craccivora Koch (Hemiptera: Aphididae) is attacked by both L. orientalis and Lysiphlebus fabarum (Marshall) (Hympenoptera: Braconidae). I also found that L. orientalis may prefer slightly older A. craccivora hosts than L. fabarum. These results indicate that while transgenerational fecundity compensation may be an interesting and novel physiological phenomenon present in multiple aphid-parasitoid associations, it may be relatively inconsequential for populations of aphids and their parasitoids.
Description
University of Minnesota Ph.D. dissertation. March 2017. Major: Ecology, Evolution and Behavior. Advisor: George Heimpel. 1 computer file (PDF); vii, 81 pages.
Related to
Replaces
License
Collections
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Kaiser, Matthew. (2017). Transgenerational Fecundity Compensation And Post-Parasitism Reproduction By Aphids In Response To Their Parasitoids. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/188956.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.