Answer: The author introduces his idea by:
D. Contrasting his experience with the statement of another expert.
Step-by-step explanation: In the opening paragraph of the excerpt, the author refers to Dr. L. 0. Howard and his statement that the mosquito rarely goes far from its birthplace. However, the author disagrees with Dr. L. 0. Howard's statement and refers to his own experience with mosquitoes in New Jersey, which offer endless evidence of power to travel as well as to resist cold and wind. Therefore, the author's idea is introduced by contrasting his experience with the statement of another expert.