Group 3 INteractions Organisms-EnVironment : mechanisms and responses to global changes

Our team is motivated by its curiosity for Nature and living forms. The team covers a broad range of biological models that can be either conserved in the lab just for the time of an experiment or reared for a long time for large projects.

Thermal biology.

We study the thermal biology of arthropods in the context of environmental fluctuations both in the natural habitat and generated by the activities of the organism (eg, hematophagy). A comparative approach integrating organisms from thermally contrasting habitats allows us to comprehend the link between environmental variability and thermal adaptations. This topic includes two axis: (1) the thermal tolerance and thermoregulation of insects under environmental constraints, and (2) the physiological and biochemical basis of thermal tolerance. We work with both aquatic and terrestrial insects from temperate and (sub)tropical regions to determine which groups is more vulnerable to warming. Organisms can thermoregulate behaviorally or initiate repair processes at the molecular level when under heat stress. Hematophagous insects developed strategies to deal with thermal stress when feeding on hot-blood, and these strategies have direct impacts on the microorganisms transmitted to the host. Studying these processes can reveal the potential targets for the control of insect vectors.

Biological models: herbivore insects (aphids, leaf miners, spider mites etc.); hematophagous insects (mosquitoes and bugs); aquatic insects (dragonflies).

Physical ecology and bioinspiration.

The physical ecology of insects is studied along three main axis: (1) Locomotion in granular environments and at the surface of water, studied with a physical approach to understand the difficulty of most insects to move on granular surface such as sand, (2) The role of fluid dynamics in the detection of chemical signals, with studies at the interface between physics and chemistry looking at the micro-physics of olfaction in insects (eg, the trajectories of pheromone molecules around insect body, antennae and receptors) and the probabilities of capturing molecules, (3) The physics of vibration propagation across complex environments (eg, forest leaf litter) in the context of communication in arthropods, and (4) The transfer of knowledge to bioinspired microtechnologies in the context of artificial noise to search for explosive materials. Our approach is mostly experimental: our team has various tools for optical metrology including Laser Doppler Vibrometers and Tomographic Particle Image Velocimetry (TomoPIV). Finally, finely tuned prey-predator interactions involve fluid dynamics, trajectories of both interacting species and the structure of the environment. We have proposed the modeling basis to study these relationships using game theory.

Biological models: locomotion of ants, gerris and whirligig beetles; nocturnal moths; wolf spider.

Sensory biology and cognition.

Fluctuating and heterogeneous environments influence the transmission of stimuli and the ability of organisms to detect cues and signals. These cues and signals are essential for survival. Our integrative studies deal with processes from the propagation of stimuli, the structure of sensory organs, the use of these stimuli in behavioral responses (eg, spatial orientation), and the synchrony of biological rhythms or learning. We mainly focus on processes linked to sensory biology and cognition in arthropods that are vectors for human disease as models to study the evolution of hematophagous life-style. These studies integrate the biological responses to methods used to control disease transmission (eg, repulsive molecules)or to manipulate the behavior of vectors.

Biological models: various species of mosquitoes, the bug Rhodnius prolixus.

Global change ecology.

The three previous topics generate fundamental elements to a more implied research on

(1) The ecological impacts of climate change that we study with a biophysical approach considering the amplitude of micro-climate change in various ecosystems to estimate the vulnerability of ectotherms across biomes. These studies are also linked to biological conservation challenge.

(2) The dynamics of invasive species which represent a major treat for biodiversity in interaction with climate change. Our modeling approach allows to improve our understanding of the mechanisms at play during invasions and to develop decision-making tools to test various control strategies.

(3) Agroforestry is a promising agroecological strategy to solve dramatic environmental problems. Our studies on agroforestry allow us to enlarge the impact of our research on behavioral ecology and spatial ecology in structured environments. We initiated studies on biological control conservation by focusing on carabid beetles, their displacements and physiology.

Biological models: pest species on apple; several invasive species (termites, pine processionary moth, box tree moth); carabidae species in agricultural fields.