A gravity model for the spread of a pollinator-borne plant pathogen

Area of Science:

• Ecology
• Plant Pathology
• Epidemiology

Background:

• Plant pathogens are often transmitted by arthropod vectors.
• Vector movement and host selection are influenced by host quality and spatial distribution.
• Understanding these factors is key to predicting disease spread.

Purpose of the Study:

• To develop a "gravity" model for plant pathogen spatial spread.
• To investigate the role of insect foraging behavior in disease transmission.
• To model the spread of the smut fungus *Microbotryum violaceum* in *Silene latifolia*.

Main Methods:

• Developed a gravity model incorporating insect foraging behavior.
• Modeled pathogen spread based on host plant quality and vector movement.
• Fitted the model to time-series data of *M. violaceum* transmission in experimental plots.

Main Results:

• The gravity model provided a superior fit compared to mean field or distance-dependent models.
• Vector foraging behavior was shown to be a significant driver of spatial disease patterns.
• Demonstrated predictable variation in pathogen exposure due to foraging patterns.

Conclusions:

• Active vector foraging is critical for generating spatial patterns of plant disease incidence.
• Foraging behavior influences pathogen-mediated selection on floral traits.
• The gravity model offers a valuable tool for studying vector-borne plant diseases.