Category B – Mosquito Biology and Control Practice Test

Physical control solutions are about altering the environment to prevent mosquitoes from breeding or surviving without using chemical agents. Chemical spraying of larvicides clearly applies a chemical to kill larvae, so it’s a chemical control, not a physical one. The other options involve modifying water flow or land to reduce standing water and breeding sites—open circulation of tidewater and re-grading land are classic habitat/physical modifications. Stocking with mosquito fish is a biological approach, which uses predation rather than habitat change or chemicals. In the material's framing, the option that uses chemicals isn’t listed as a physical control, making it the best answer.