Answer:
To balance the food chain.
Step-by-step explanation:
Mosquitoes actually play a big part in the food chain.. Animals such as frogs eat them, and what if other foods that frogs eat go out(Not saying it's gonna happen, its just a what-if)? They will have to resort to the mosquitoes. And if those were gone, the frogs would go out. Then a certain number of animals maybe maybe not would have to develop a new diet due to the extinction of frogs.