Table 1 List of model parameters, descriptions, and initial conditions for agent-based model of spotted lanternfly movement under differing scenarios.
From: Human-mediated dispersal drives the spread of the spotted lanternfly (Lycorma delicatula)
Model parameter | Description | Value(s) |
|---|---|---|
Number of years (t) | Number of years (i.e., model iterations or time steps) that simulations are run for. Each time step t equals a 1-year period | 13 |
Initial location (Lat/Long) | Spatial coordinates of a single cell where individuals are "introduced" into the landscape. This is the location where the spotted lanternfly was first detected in Berks County, Pennsylvania | 40.415240°N, − 75.675340°W |
Starting population size (N) | Number of individuals at model initialization | 1000 |
Carrying capacity (K) | A deliberately large population carrying capacity to coerce exponential population growth | 10^15 |
Intrinsic rate of growth (r) | Hypothetical population growth rate (i.e., births - deaths per generation period). This term was varied among four different values of r to tune our model among differing scenarios in comparison to observed spotted lanternfly population spread | (0.25, 0.5, 1.0, 1.5) |
Environmental stochasticity term (Var) | Logistic growth model term used to add variation into estimated population sizes representing environmental stochasticity within the modeled system | unif(− 0.5, 0.5) |
Mean adult survival probability (ϕ) | Survival probability for adults that is randomly drawn from a uniform distribution each time step, ranging between 0.5 and 0.9 | unif(0.5,0.9) |
Mean movement coefficient (q) | Parameter governing individual movement decisions: either best choice (0.99) or random (0.01) choice decisions | (0.01, 0.99) |
SD movement coefficient | Standard deviation of movement coefficient to provide additional variation in behavior decisions among individuals | 0.05 |
Human-mediated movements (h) | The maximum number of newly-established spotted lanternfly populations caused by human-mediated movement events per year (e.g., transport of egg cases or gravid adult females and subsequent successful establishment). We modeled different scenarios that consist of up to 0 (no human movement), or 3, 5, 7, and 10 new populations established at each time step drawn from a uniform distribution between 1 and either 3, 5, 7, or 10 per scenario | (0, unif(1, 3), unif(1, 5), unif(1, 7), unif(1, 10)) |
