a) Insect population :
1. Insect develop immunity to the insecticide used.
2. And it has any effect on the insect it targets. Hence the number of insects increases,
b) Soil ecosystem :
1. A large percentage of insecticide chemicals remain in the soil.
2. These chemicals kill the worms in the soil which are useful to soil.
3. Hence soil ecosystem destroys by increasing the concentration of salts in the soil.
