From Ecology to Biosecurity

Introduction

• Biological invasions are a consequence of human population growth and the development of worldwide trade. They show no sign of a decrease.
• The movement of goods and people relaxes the dispersal limitations but environmental constraints remain:
  • Presence of suitable trophic resources (hosts)
  • Suitable climate conditions
• Ecological niche models are used to assess the range of environmental conditions that prevail at site where a species is established
• They help mapping the potential distribution of species when it is introduced in new regions

Ecological Niche Models: principle

The example of Agrilus planipennis, the emerald ash borer

• Species native to East Asia accidentally introduced to North America and Eastern Europe
• Where could it be a biosecurity problem in Europe?

Agrilus planipennis - hosts distribution

Agrilus planipennis - climate suitability

Models contribute to invasion preparedness

• Anticipate possible introductions or evaluate future expansions
• Inform authorities and public
• Help managers to set up accurate surveillance plans
• Take preventive measures, launch research program
• Develop pre-emptive biological control i.e. prepare biocontrol before invasive species arrive
• Assess impacts of climate change upon biorisk

Taxonomic level

• Models are traditionally developped at the species level BUT
• Might not always capture the local adaptations
• Genetic information could be of great help !

The example of Xylosandrus crassiusculus

• Invasive ambrosia beetle recently introduced in Europe
• Species comprising two different genetic lineages (Urvois et al. 2023)
• These lineages have different geographical distributions
• Only lineage 2 is present in Europe

❓ Are the climatic niches equivalent?

❓ Is the associated biorisk similar?

Xylosandrus crassiusculus - climatic niches

Xylosandrus crassiusculus - Potential distribution

Climate changes, so does biorisk!

Areas currently suitable for lineage 2 (in blue)

Climate changes, so does biorisk!

Areas currently suitable for lineage 2 (blue) and in 2041-2070 (red)

Climate changes, so does biorisk!

Important commercial seaports will become climatically suitable in 2041-2070

Perspectives

• Ecological niche models are usually developped species by species

One interesting approach with xylophagous insects would be to:

• Identify together the species that are the most interesting/worrying
• Developp an ensemble approach to provide a multispecies risk analysis
• Evaluate how it would change with climate change