Group Menzel

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
  • Behavioural responses to chemical footprints in ants
  • Interactions of insect surfaces with capture threads of cribellate spiders
  • Evolution and phylogenetic signal of cuticular hydrocarbon profiles in ants
  • CHC diversification in mutualistic ant-ant associations (parabioses) in tropical South America
  • Relations between ecological niches and body morphology in tropical and temperate ants
  • Antipredator behaviour and non-consumptive effects of spider predators on arthropod prey: behavioural interactions, chemical cues, and ecological consequences

At the moment, I offer three master theses. Starting date is flexible, January 2022 or later. Check them out:

Learning and orientation in ants – how do chemical cues affect ant behaviour?

Agent-based model of foraging behaviour in ants

Physico-chemical properties of communication signals in mutualistic ants (including a research stay in Paris)

There may also be master theses on tropical ant ecology, with field work in French Guiana, starting in 2022.

 

Further topics for research practicals, bachelor, diploma or master theses include:

  • Niche differentiation in Central European ants
  • What do ants eat? Dietary niche partitioning within and across ant species
  • How do different ant species respond to chemical footprints of other insects?
  • Can ants learn to respond to certain footprints?
  • How does individual personality influence ant behaviour?
  • How does gene expression change when an ant acclimates to different temperatures?
  • Fungal communities in ant nests and on individual ant workers
  • How do cuticular hydrocarbons CHCs influence the resistance of insects against pathogens?
  • Physico-chemical properties of communication signals in ants and other insects
  • How is the chemical CHC composition linked to its physical properties?
  • Interactions of spiders with their insect prey
  • Mutualism or not? Costs and benefits in ant-aphid symbioses
  • Chemical diversification in ant species of tropical South America
  • How are chemical profiles and drought tolerance related across arthropod taxa?
  • Which factors determine the temperature niche and the drought tolerance of an insect?
  • How is CHC composition linked to the waterproofing ability of the CHC layer?

 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

Please drop me an email if interested.

 

GROUP MEMBERS

The 'ant crew' during our field season in French Guiana, October 2018

Group leader

Post-doctorals

PhD students:

  • 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)

Master students:

  • Ronja Krüsemer (Insect cuticular hydrocarbons as barriers against fungal infection)

Bachelor students:

  • Raúl Rojas Feilke (Interspecific behavioral differences of the three ant species Lasius niger, Tetramorium caespitum, and Formica rufibarbis)
  • Merle Rohovsky (Repeatability and behavioural syndromes in the ant species Lasius niger, Tetramorium caespitum, and Formica rufibarbis)
  • Dominik Heidt (Wirkung der temperaturabhängigen Interaktionen von Fangfäden cribellater Spinnen und kutikulärer Kohlenwasserstoffen von Insekten)

Former PhD students: