What is the primary morphological difference between Anopheles and Culex mosquitoes?

What is the primary morphological difference between Anopheles and Culex mosquitoes?

• A. Anopheles rests horizontally with a humped thorax; Culex rests at an angle with the body and proboscis in a straight line.
• B. Anopheles rests with curved abdomen; Culex rests straight.
• C. Anopheles rests tip-down; Culex rests tip-up.
• D. Anopheles rests at an angle with the body and proboscis in a straight line; Culex rests horizontally with a humped thorax.

Answer: (D)

The key idea here is how these mosquitoes hold themselves at rest. Anopheles tends to sit with its body angled to the surface, giving a slanted, upright-looking profile. Its thorax is arched, producing a subtle hump that you can often notice from above, and the proboscis tends to align with the body along that line. Culex, on the other hand, rests more flat against the surface, with the body oriented horizontally and a relatively less pronounced thoracic arch. So the primary morphological difference is the resting posture (angled for Anopheles vs horizontal for Culex), reinforced by the stronger thorax curvature in Anopheles.

The key idea here is how these mosquitoes hold themselves at rest. Anopheles tends to sit with its body angled to the surface, giving a slanted, upright-looking profile. Its thorax is arched, producing a subtle hump that you can often notice from above, and the proboscis tends to align with the body along that line. Culex, on the other hand, rests more flat against the surface, with the body oriented horizontally and a relatively less pronounced thoracic arch. So the primary morphological difference is the resting posture (angled for Anopheles vs horizontal for Culex), reinforced by the stronger thorax curvature in Anopheles.