Modeling the within-plant distribution of Bemisia tabaci biotype B using patterns of aggregation and leaf selection as predictors

Most predator-prey models assume that distribution of prey patches and their size is irrespective to where the predator forages. However, the systematic distribution of toxins and nutrients within plants and the degree of vulnerability of insect herbivores to plant defenses results in close associations between plant architecture and herbivore distributions. For instance, generalist herbivores such as the Silverleaf whitefly (SLWF) (Bemisia tabaci biotype B) are vulnerable to plant toxins, and cluster in mid-aged leaves where they reduce their exposure to plant defenses. As part of an effort to construct a predator-prey model involving the SLWF, the objective of this research is to develop a model to simulate the spatial distribution of SLWF nymphs on virtual tomato plants. The model was developed using object-oriented programming and requires the plant size and the number of SLWF individuals to distribute as inputs. The output is a plant model made of architectural attributes and leaves containing leaflets with different numbers of SLWF individuals. The architectural attributes are simulated using a tomato plant model developed elsewhere, and the SLWF individuals are distributed based on the infestation probability per nodal position and the aggregation pattern of the SLWF within plants. Parameter estimation was performed using the number of nymphs per leaflet censused from 30 artificially infested tomato plants. The model was validated using datasets from the literature and our research. Use of this model could reduce time and costs needed to evaluate biocontrol agents by improving the precision of predator-prey models used for this purpose.