The overuse of any pesticide will make the pest develop immunity to it, by adapting to it.
Step-by-step explanation:
Any insect pest that infects a cop is controlled by pesticides. These insect species show variation in the DNA of different forms that attack different crops but in general one crop has the same pest and is affected on by the pesticide much the same.
The overuse of the same pesticide however is detrimental for the humans. The pests eventually are able to adapt to the pesticide and develop an immunity against it for the survival of their species.
Then during reproduction they pass on this immunity to the offspring, making that particular pesticide useless.