Mosquitoes (Culicidae) are identified by which combination of features?

• A. Piercing-sucking proboscis; scales on wing veins
• B. Wings reduced to halteres; clubbed antennae
• C. Mouthparts for chewing; stout bodies
• D. They are primarily aquatic as adults

Answer: (A)

The key trait used to identify mosquitoes is their combination of a long piercing-sucking proboscis and scales on the wings. The proboscis is specialized for piercing skin and drawing blood, a distinctive feeding adaptation of Culicidae. The scales on the wing veins give mosquitoes their recognizable wing appearance and help distinguish them from other flies. The other statements misrepresent mosquito biology: halteres are a feature of many flies, not wing-reduced insects here; chewing mouthparts and stout bodies describe different insect groups; and adults are not primarily aquatic, since only the larvae are aquatic.