Which order includes flies and mosquitoes?

• A. Lepidoptera
• B. Hemiptera
• C. Orthoptera
• D. Diptera

Answer: (D)

Flies and mosquitoes are in the order Diptera. The name means two wings, and these insects actually have a single pair of functional wings for flight, while the other pair is reduced to small balancing organs called halteres. That combination—one pair of wings plus halteres—defines this group and differentiates it from others. For example, Lepidoptera (butterflies and moths) have two pairs of scaled wings, Hemiptera (true bugs) have a different wing and mouthpart arrangement, and Orthoptera (grasshoppers and crickets) feature large hind legs for jumping along with their own wing types. So the order that includes flies and mosquitoes is the one characterized by a single pair of wings and halteres.