SOCIAL INSECTS AS SOLITARY VEHICLES

Open Access
- Author:
- Sola Gracia, Emilia
- Graduate Program:
- Ecology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 05, 2017
- Committee Members:
- David Peter Hughes, Dissertation Advisor/Co-Advisor
David Peter Hughes, Committee Chair/Co-Chair
Nina Ellen Jenkins, Committee Member
Victoria Anne Braithwaite-Read, Committee Member
Ephraim Mont Hanks, Outside Member - Keywords:
- Ophiocordyceps unilateralis sensus lato
Beauveria bassiana
Camponotus castaneus
Camponotus pennsylvanicus
social dynamics
cadaver managment
disease dynamics
fungal morphology
group defense
movement
trophallaxis
semi-natural arenas - Abstract:
- Parasite-host interactions affect more than the two main characters. Organisms living in tight-knit communities depend on each other in order to survive. Individuals harboring a parasite can affect the delicate balance within these communities. While on the other hand the community could also have a strong effect on a parasite’s life cycle. I explore the effects infected individuals have on the within-nest dynamics of ant colonies. Additionally, I investigate the effects of infectious and non-infectious cadaver exposure have on worker behavior, as well as determine the effects workers have on the fungus protruding from the infectious cadavers. Using both a coevolved fungus, Ophiocordyceps unilateralis sensus lato, and a generalist fungus, Beauveria bassiana, I found infected workers do not strongly affect the within nest dynamics of Camponotus castaneus, the natural host of O. unilateralis s. l. Furthermore C. castaneus and C. pennsylvanicus manage infectious and non-infectious cadavers differently. Workers from C. castaneus colonies are adept in quickly removing cadavers with internal and external fungal development. While C. pennsylvanicus workers must come in contact with fungal tissue in order to recognize the disease threat. However, I found C. pennsylvanicus workers to be highly effective in reducing the infectivity of hazardous fungal conidia (i.e. asexual spores). Such findings could be caused by the wood nesting ecology this species has, as well as the higher aggression towards infectious cadavers. My research lays the foundation for future studies which focus on using semi-natural settings to study parasite-host and community dynamics.