Use the EIL simulator below to see how EILs work. This EIL simulator allows you to adjust the parameters discussed on the previous in order to see how they affect the Economic Injury Level. You can use the arrow buttons to adjust the values up and down. When you have set the EIL at the desired level, press play. When (or if) the pest population reaches the EIL level, press the spray button to knock the population back below economically damaging levels.
To see the effects of the pests on your harvest, you can adjust the number of pests to zero in the population bar and run the simulation. This will give you an idea of how much crop you can harvest in a completely pest-free environment. You may also want to test the effect of numerous or particularly damaging pests. Setting the initial pest population to a high number (e.g. 50) or setting the injury per pest or damage per injury levels high will certainly reduce harvests.