Question

The main prey for the frogs in a certain pond are dragonflies. If the number of dragonflies is greatly reduced because of pesticide usage, how could the frogs adapt in order to survive?

Answer 1

Either finding a new prey or the population
would decrease another option is to move into a new pond 

Answer 2

Answer: Frogs would start eating some other kind of insect or else they would migrate to some other place.

Explanation: The population of frog is dependent on the dragonflies for their food and if the number of dragon flies are reduced due to the effect of pesticides then there are two options available for the frog.

First, the frogs can shift their preferences from dragon flies to some other insect.

Secondly, the frogs can migrate to some other place to fulfill the need of food.