Zombie fungi in the tropics: Ecological insights into their impact on arthropod host communities
Background
Entomopathogenic fungi represent a fascinating and ecologically significant group of microorganisms, particularly in tropical ecosystems, where their prevalence and diversity have profound implications for arthropod populations and overall ecosystem dynamics. These fungi are adept pathogens, capable of infecting a wide range of arthropod hosts, making them vital components of natural pest control systems. The interplay between entomopathogenic fungi and their arthropod hosts in tropical ecosystems presents an intriguing area of scientific inquiry. These fungi often coevolve with their arthropod hosts, resulting in intricate and finely tuned interactions that can have cascading effects throughout the ecosystem. The study of these interactions not only deepens our understanding of the complexities of tropical biodiversity but could also shed light on the cryptic diversity concealed within these fungi.
Problems
However, despite the growing recognition of the vital roles played by zombie fungi in tropical ecosystems, significant gaps persist in our knowledge. The complex and often cryptic interactions between entomopathogenic fungi and their arthropod hosts challenge our ability to comprehensively understand their ecological dynamics. Moreover, the sheer diversity of entomopathogenic fungi in tropical regions suggests the presence of numerous undiscovered species and their specific ecological niches remain largely unexplored. Addressing these limitations in our understanding is essential for a more complete picture of the ecological intricacies involving zombie fungi and arthropod host communities in the tropics.
Goals
Arthropods infected with zombie fungi were collected from primary rainforests in Borneo, Malaysia. All samples originate from different altitudes on Mount Kinabalu, collected following a standardized framework. Using a morphological and molecular approach, we want to address the following questions: What are the entomopathogenic fungus–host associations in the sampled communities (i.e., determine fungus and host arthropod species)? What are the community parameters determining this associations network (i.e., identify whether fungi are specialists or generalists, identify resilience of the network to removal of members, identify host groups that are commonly vs. rarely infected by entomopathogenic fungi)? In addition, depending on the student’s interests, the research may incorporate a chapter that focuses on fungal cryptic diversity—a fungal name may hide multiple cryptic (morphologically similar) or near-cryptic species that are highly host specific.
The student will become familiar with a variety of research methods, including integrative fungal taxonomy, forest ecology, statistical analysis, community networks, regression analysis, and molecular laboratory techniques.
References
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Chaverri P, Liu M, Hodge KT. 2008. A monograph of the entomopathogenic genera Hypocrella, Moelleriella, and Samuelsia gen. nov.(Ascomycota, Hypocreales, Clavicipitaceae), and their aschersonia-like anamorphs in the Neotropics. Studies in Mycology 60: 1-66. https://doi.org/10.3114/sim.2008.60.01
de Bekker C, Beckerson WC, Elya C. 2021. Mechanisms behind the madness: How do zombie-making fungal entomopathogens affect host behavior to increase transmission? mBio 12(5): e01872-21. https://doi.org/10.1128/mbio.01872-21
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