Simulation of the effects of natural enemies on an insect population

This page is the starting point for a computer simulation model for insect population studies. In the form below you can enter sets of data that are used to start the simulation program. Initially the form will show default values, which can be replaced by your own values. For most parameters you can enter a low and a high value (see notes below). Then click the Start Simulation button to see the results. Read the introduction to learn more about this simulation program.

	Low	High
Population development
Eggs per female				Eggs
Sex ratio				% females
Eggs days to hatch				Days
Larva days to pupa				Days
Pupa days to adult				Days
Adult days to egg				Days
Egg mortality factors
Egg parasitoids				%
Egg predators				%
Egg other (weather, diseases)				%
Larva mortality factors
Larva parasitoids				%
Larva predators				%
Larva other (weather, diseases)				%
Pupa mortality factors
Pupa parasitoids				%
Pupa predators				%
Pupa other (weather, diseases)				%
Adult mortality factors (before egg laying)
Adult predators				%
Adult other (weather, diseases)				%
Other settings
Start population size (eggs)				Number of eggs to start the simulation
Number of generations				Number of generations to simulate (maximum 40)
Maximum population size (larvae)				Simulation stops when the number of larvae exceeds this number
Variability				Variability factor (0-100)
				Click this button to run the simulation

Notes

For most parameters you have entered a "low" and a "high" value.

• For density dependent factors (e.g. mortality caused by parasitoids or predators) the program will use an algorithm to select a value which is near the "low" when the population density is low, and near the "high" when population density is high.
• For factors that are not density dependent (e.g. other mortality factors such as bad weather conditions) the program will in each cycle (generation) at random select a value between the "low" and the "high".

This variability factor (0-100%) makes the simulation more unpredictable by introducing at random some variation on top of the data that you entered. It varies the "low" and "high" values of density dependent factors, simulating an additional effect of good or bad weather conditions. A higher value will create more variation of the numbers that you entered (different values in each cycle). 0% means no variability, so the program will exactly use the low and high values that you entered. 100% means maximum variability.

The program will first verify the data you entered and if necessary make some corrections. For example, if you set a "low" value higher than the "high" value, the program will use the lowest one for both "low" and "high".