Vector-borne parasite invasion in communities across space and time

Area of Science:

• Ecology
• Epidemiology
• Parasitology

Background:

• Vector-borne parasite transmission is often facilitated by generalist vectors, enabling cross-species pathogen spread.
• Existing theory inadequately describes how host species diversity influences parasite invasion dynamics in these complex systems.

Purpose of the Study:

• To develop a model exploring how variations in host community composition and abundance affect parasite invasion potential.
• To quantify parasite invasion potential across diverse host communities using the community basic reproductive ratio.

Main Methods:

• A mathematical model was created for vector-borne parasite transmission dynamics within host communities of varying richness and species abundance.
• Community invasion potential was assessed by comparing parasite's community basic reproductive ratio across different host community compositions (subsets and novel species).
• Vector abundance was modeled to scale with or independently of community size, incorporating feeding opportunities and non-host factors.

Main Results:

• Host community composition and abundance significantly alter parasite invasion potential.
• An underappreciated mechanism was identified where simultaneous changes in average host competency and vector-to-host ratio profoundly influence invasion dynamics.
• The model demonstrated how species introduction or loss impacts overall invasion risk.

Conclusions:

• Host community structure is a critical determinant of vector-borne parasite invasion success.
• Understanding the interplay between host diversity, competency, and vector abundance is crucial for predicting and managing parasite transmission.
• The developed model provides a framework for assessing parasite invasion potential under varying ecological scenarios.