Evolutionary Chemical Ecology and Biotic Interactions
Keywords: chemical ecology, evolution of cuticular hydrocarbon profiles, antipredator behaviour, interspecific interactions, ecosystem functions of ants, ant community ecology, division of labor, tropical rainforest, ants, spiders, aphids.
RESEARCH INTERESTS
Our group is interested in interspecific interactions between different ant species and between ants and other arthropods. Interactions between ant species can be competitive and aggressive, but also mutualistic, commensalistic or parasitic. We study these interactions from two perspectives: from a top-down perspective, we study community organization and ecosystem functions in ant communities in tropical rainforests. In this context we are also interested in biodiversity and ecosystem functions of ants and other arthropods in conventional agriculture and dynamic agroforestry.
From a bottom-up perspective, we investigate the mechanisms in specific interactions between few species. We study behavioural interactions and chemical cues that are involved in ant-ant and ant-aphid interactions, as well as predator-prey interactions between other arthropods.
These interactions are often driven by chemical cues – cues from the insects’ body surface (cuticular hydrocarbons) or indirect cues, such as chemical footprints. We recently showed that ants respond to chemical footprints of other colonies and species, which may have great effects on their foraging behaviour. In general, the most important intra- and interspecific communication signal in ants and other insects are cuticular hydrocarbons (CHC). Therefore, we do not only investigate their role in interactions, but also study the proximate and ultimate factors that shape their composition. CHC experience selection from multiple sides, since beside their communication function they also act as waterproofing agent. In our group, we study how CHC profiles evolve and diversify in response to selection pressures arising from their multiple functions. Furthermore, we study how individual ants can adjust their profiles in response to different climatic conditions. To understand the molecular basis of CHC biosynthesis and evolution, we analyse gene expression in ants from different climatic conditions and in closely related, but chemically different ants.
Current research questions include:
- Climatic impacts on the CHC profile of ants, and their consequences for drought resistance, nestmate recognition and CHC material properties
- Avoidance of competition: Behavioural responses to chemical footprints in ants
- Interactions of insect surfaces with capture threads of cribellate spiders
- CHC diversification in mutualistic ant-ant associations (parabioses) in tropical South America
Methods used:
- Field experiments
- Behavioural experiments in the lab
- Chemical analyses of cuticular hydrocarbons and fatty acids using GC-MS
- Microrheological measurements of viscosity (in collaboration with Bérengère Abou, Paris)
- Transcriptome analyses (RNAseq)
- microbial assays
- Agent-based modelling
From Summer semester 2024, I can offer a range of Master and Bachelor theses. Topics include:
- How do climate conditions influence the CHC profile and the drought resistance in Central European ant species?
- How do tropical rainforest ants differ in drought resistance, and how is this linked to their microhabitat and to their CHC profiles? (with field work in Peru)
- Fungus-ant interactions: Which fungal communities inhabit the body surface of ants, and how can they protect themselves against fungal infections?
- Temporal variation of pollinating insects on the JGU campus
- Diversity of epigaeic arthropods in the Ober-Olmer Wald
- How does cuticular hydrocarbon composition influence desiccation resistance? Studies on the chemical and physical aspects of CHC layers.
- Which genes are involved in acclimation to different constant and fluctuating conditions? (Master thesis only)
For the Peru project, I have an advertisement, which you can read here.
Please drop me an email if interested in writing a thesis in my group.
GROUP MEMBERS
Group leader
Post-doctorals
PhD students / scientific employees:
- Vanessa Menges: The role of chemical footprints for foraging and competitive interactions in ants
- Lucas Jäger: The impact of cuticular chemistry and surface morphology of arthropods on adhesion forces in cribellate and ecribellate spider threads (co-supervisor Anna-Christin Joel)
- Selina Huthmacher (Biophysical and functional consequences of cuticular hydrocarbon variation in ants)
- Shadi Karimifard (Genomic and gene regulatory basis of rapid evolutionary diversification of a multifunctional trait) (co-supervisor Barbara Feldmeyer)
- Sascha Schlüter (The role of lipid physical properties for the multifunctionality of insect cuticular hydrocarbons)
- Katharina Wittmann (Interaktiver Insekten-Campus) (Zusammenarbeit mit Daniel Dreesmann)
Master students:
- Gülsem Kara (Can ants learn responses to footprints?)
- David Ruchatz (Acclimatory CHC changes of ants from different climatic regions analysed through automated integration)
- Christine van Ooyen (Floral changes over time as revealed by pollen metabarcoding)
- Philippa Musiolik (Acclimation and survival of Myrmica ants)
Bachelor students:
- Morwen Liebscher (Cuticular hydrocarbon variation and desiccation resistance in North American desert ants)
- Daniel Burket (Cuticular hydrocarbons and sexual selection in Hawaiian crickets)
- Marieke Theiner (Insect Diversity and Abundance on the Johannes Gutenberg University Campus)
- Hannah Bauer (Nachtfalterdiversität auf dem Campus der Uni Mainz)
Former PhD students: