INSECT BEHAVIOUR & SYMBIOSIS

Our main research goal is to examine how ecological and evolutionary concepts affect forest insects and their biotic environment. We aim to develop methods for the long term protection of the ecological and economic ecoystemservices of native forests threatened by ongoing climate change and biodiversity loss.

A transdisciplinary approach, integrating subjects such as evolutionary biology, ecology, behavioral biology, microbiology and chemical ecology, allows us to gain a better understanding of the life of forest insects and their ecological relationships with other animals, plants and microorganisms, and to determine the role of these relationships for forest insect population dynamics. Wood-boring beetles are our model organism, in particular bark beetles, and their associations with bacterial and fungal symbionts. We explore these multipartite symbioses in all their microbiological, molecular and chemical details to gain an overarching understanding of how these associated organisms influence each other and either facilitate or hamper their insect hosts in colonizing trees.

Establishing a laboratory breeding system for various bark beetle species is one of our most important achievements to date. The system enables the consecutive rearing of beetles and experimental manipulation of normally inaccessible beetle nests usually hidden below the bark or inside the wood. By combining this technique with studying bark beetle population dynamics in the field we are able to study these insects at different scales.

Along these lines our core fields of research are: (1) studying the influence of macro- and microorganisms on forest insects in the field, (2) experimentally manipulating the relationship between these organisms (hosts and symbionts) in the lab and observing the physiological and ecological consequences, (3) the histological study of the transmission of microorganisms (especially symbionts) by insects, and (4) the chemical ecology and molecular genetic basis of insect-microorganism interactions.

Current projects

FOREST PROTECTION

Forest protection and pest management are crucial for successful and sustainable forestry. Research in these fields is multidimensional and encompasses biology, ecology, chemoecology, forest management and more. Forest practitioners need fast and economic solutions, while nature conservation calls for low impact solutions and scientists hope to understand insect communication and the ecological processes behind insect breakouts.

Through our research, we aim to understand the basics of insect behavior, communication and dynamics, while also providing forest practitioners with practical knowledge. Most of our studies are carried out in collaboration with the forestry sector, take place in the field and are supplemented by lab work and experiments conducted under semi-natural conditions.

We try to involve students in our research wherever possible, fusing research and teaching. Currently our main focus is to improve the insecticide-free management of bark beetle populations on spruce and fir as well as on early detection and monitoring.

Current Projects

HOST-MICROBIOME INTERACTIONS

Microbes are everywhere, in fact there is no organism that does not interact with them in some way. These interactions can be diverse and range from pathogenic to mutualistic. Specifically, host-associated symbionts (= microbiome) have been shown to affect diverse biological host traits such as nutrition, development, immunity and even behavior. Host-associated symbionts can be key drivers of an organism’s ecology and evolution.

Bark beetles are one of the most species rich herbivorous insect groups and are perfect for studying host-microbiome interactions: They have a highly diversified ecology and host-plant usage. While the importance of their symbioses with specific fungi for the completion of their life cycles is acknowledged, little is known about the role of the diverse bacteria and other fungi (such as yeasts and molds) in the various bark beetle galleries. This provides many opportunities for exploring microbe-beetle interactions, the symbiotic fungi, as well as the tree environment.

 

    Current Projects

    BIODIVERSITY – “GREEN WITTENTAL”

    With its 1.5 hectares of open fields, a forest stand, greenhouses and laboratories just east of Freiburg along the Dreisam Valley, the Chair of Forest Entomology and Forest Protection offers the perfect setting for entomological and ecological studies.

    The ongoing biodiversity crisis (keywords “insect decline”, “bird decline”) further highlights the lack of practical offers for teaching and further developing species knowledge. We plan to offer a variety of university courses at this unique location, and to create a freely accessible place for students to learn and practice outside of courses.

    We will also be working with students to promote biodiversity by restoring habitats and implementing insect-friendly management through relatively simple measures (modified mowing regimes of flowering meadows, ponds, stone walls, dead wood, nesting aids, etc.). These habitats will then be used for teaching, research and educational outreach regarding biodiversity and nature conservation.

    Completed projects and research includes:

    • An inventory of flora and fauna
    • An inventory of Carabidae and other ground-dwelling arthropods
    • An inventory of saproxylic coleoptera in the forest stand as well as research on their swarming behavior
    • The Malaise trap as a method for catching nocturnal flying insects
    • Monitoring wild bees
    • Do managed bees have effects on the abundance and species richness of wild bees?
    • Assessing the relationship between habitat characteristics and insect communities using the entomological umbrella method

     

    Current Projects