Simulation

Simulation 2: A reproduction factor based on birth and mortality The size of an insect population fluctuates from day to day. Every day some new insects are born and every day some insects die. We have already seen that the population size for one generation depends on the size of the previous generation, and that […]

Simulation 3: Limiting population growth In simulation 2 we started using a reproduction factor (r) which depends on birth (b) and mortality (m) factors. But we have also seen that when birth and mortality are fixed values the simulation is not realistic. The population either explodes (r is positive) or it dies out (r is

Simulation 4: Simulating the use of pesticide to control an insect population We have already a model to simulate the development of an insect pest population (see Simulation 3). Now let’s see how we can simulate what happens if a farmer sprays pesticides to control the pest. We will have to decide when to spray,

Simulation 5: Simulating the use of pesticide at a threshold level The calendar spraying we saw in simulation 4 is simple, but it is not a good farming practice because the farmer would spray even when population densities are very low. It makes more sense to spray only when it is needed to keep the

Simulation 6: Introducing biological pest control: a predator In simulations 4 and 5 we have seen how to keep a pest population under a certain level by repeated pesticide applications. We will now see that pest populations can also be controlled by introducing natural enemies of the pest, for example spiders or egg parasitoids. When

Simulation 7: Introducing biological pest control: a parasitoid In simulation 6 we simulated the effect of a predator. The predator helps keeping the pest population at a lower level, but the population size of the predator does not depend on the pest population. Now we will introduce a different kind of natural enemy: a very

Simulation 8: Biological pest control with predator and parasitoid In simulations 6 and 7 we simulated the effect of a predator and a parasitoid. Now we will combine the two into one model. We will end up with a model where we have three insect populations (pest, predator and parasitoid) developing side by side. You

Simulation 9: Combination of biological and chemical control In simulation 8 we had already developed a rather complex model with three species (a pest, a predator and a parasitoid) interacting with each other. We have seen that the predator and parasitoid manage to keep pest populations at levels below the maximum capacity (K1). Now let’s

On these pages I will show step by step how to create a computer model to simulate pest control. We will start by creating a model to simulate the population growth of an insect population (the pest). Then we will make models to control this pest population. First we will simulate pest control using pesticides

Simulation 1: The development of an insect population Insect populations can multiply rapidly because female insects lay many eggs, often several hundred eggs per female. Let’s see what happens if one female insect lays 250 eggs. If all 250 eggs survive, and if 50% of the eggs is male and 50% female, this female would