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Design concepts

Emergence

The incidence of yellows disease on an agricultural landscape depending on its composition and configuration. Aphid population dynamics through time at different spatial scales (landscape, plot, cell) permits the identification of potential levers to reduce aphid population densities in the landscape.

Adaptation

Not applicable

Objectives

The agents display a deterministic behaviour, and do not make decisions based on a knowledge of the situation/world.

Learning

Not applicable

Prediction

Not applicable

Sensing

  • Aphids perceive the quality of the plant (depends on its development stage), that determines the proportion of aphids that will disperse out of the cell.
  • Aphids during migration perceive their host plants and will land only on cells covered with their host.
  • Aphid perceive the presence of natural enemies, and that triggers the production of winged progenies that will be able to disperse once their development into adult is complete.
  • Aphids perceive the temperatures in order to enter and end wintering, and survive during winter.
  • Aphid stocks perceive the arriving aphids and aphids that leave the cell, which triggers the increase or decrease of the number of individuals in the stock.
  • Crops in parcel cells perceive temperatures that impacts their development stage, and dates that impact sowing and harvesting.
  • Aphid stock and cell perceive the pesticide treatments, that triggers the decrease in aphid and natural enemies number of individuals.

Interaction

  • Aphids interact with their cells that provide resources (food, the type of crop influencing the aphid growth rate).
  • The development stage of the crop influences different processes: aphid growth, migration and disease spread through primary (migration) and secondary (walking) infections.

Stochasticity

During the dispersion process, the number of viruliferous aphids in flight that will land on each attractive cell is randomly sampled with weights that depend on the distance to the source cells.

Collectives

Not applicable

Observation

The proportion of sugar beet plants exhibiting yellowing symptoms are used to calibrate the model and assess the model by comparing it to data coming for real landscapes.