EIL and ET in each country for each pest is different, because each country has different economic basis. Generally, to calculate EIL and ET of pests you must consider to pest control costs and benefits from control actions. For this purpose Pedigo et al. developed a simple model of the EIL:

EIL = C/VDIK

Where C = management cost per production unit, V = market value per production unit, D = damage per unit injury, I = injury per pest equivalent, and K = proportional reduction in injury with management.

To calculate ET, you should do pest control action before pest population density reach to EIL.

In the field, infest caged maize plants with known numbers of larvae (or moths). Controls should not have larvae. Replicate several times. Estimate yield parameters at harvest. Replicate in other localities several years.

Hello,

completely, agreed with Dr Vincent

First, u should identifies Key pest.

Effective factors on EIL and ET determination:

1- Pest density

2- Plant phonology

3- Climatic conditions

4- Soil conditions

5- Plant compensation

6- Pest-Natural Enemies reaction

7- Scio-Economic conditions

Also, There r models for calculate on EIL determination:

1- Pedingo et al., 2002

2- Southwood and Norton, 1976

Best wishes

Samaneh Mahmoudvand

We may put the model of EIL and ET in a simulation using excel and it will be calculated automatically.

Thank you all for your great responses.