Marion Javal

Ongoing climate change, combined with the ever-increasing worldwide movement of goods and people, is driving plant and animal species out of their native range. These species can have major repercussions on biodiversity, ecosystem balance and human activities. Insects are the most diverse group in terms of both species numbers and ecosystem functions. They are also the group most represented among invasive animal species. Faced with the current challenges posed by global change, it is essential to characterize and understand how these invasive phenomena work, in order to anticipate their consequences on ecosystems in the short, medium and long term.

​

All my research experience has led me to question the response of insect populations to changes in their environment in a context of invasion. My work has been structured around two main axes :

​

• Axis 1: Role of Environmental Tolerance in Invasion Success – Focus on Temperature
  Understanding insect tolerance to abiotic stress is critical for assessing their invasion potential, especially in the context of rapid environmental changes. Temperature is a pivotal factor for ectotherms, influencing life-history traits and population dynamics. The thermal tolerance of insects is a highly plastic trait shaped by stress intensity, duration, and frequency, as well as microclimatic conditions. However, most existing studies fail to capture ecologically relevant stress conditions. My work aims to understand the impact of thermal regimes on population dynamics.
   

• Axis 2: Microbiome Influence on Invasion Success
  Microbial symbiosis plays a critical role in insect physiology, particularly for herbivorous species dependent on gut microbiota for essential nutrients. My work examines how the gut microbiome of insects adapts during invasion events and interacts with environmental stresses, such as sub-optimal temperatures. Preliminary evidence suggests microbiome composition varies with host plant and genotype; I try to investigate whether microbiome variations influence insect fitness (especially tolerance to abiotic stresses such as temperature or pesticides) and invasion dynamics. I also explore how environmental stressors drive microbiome changes, assessing their functional implications on the invasive success of insects pests.
  
   

Most of my current work focuses on the fall armyworm (Spodoptera frugiperda), an invasive insect native to the Americas. This species, known for its high adaptability and devastating effects on staple crops like maize, has rapidly spread across Africa, yet some regions show unexplained resistance to its establishment. However, I apply my approaches to a wide range of biological models.

​

​

​

Examples of previous projects :