Question

The antennae are absent in:

• A. Mallophaga
• B. Diplura
• C. Anoplura
• D. Protura

Hint:

Proturans are primitive, soil-dwelling hexapods that lack both antennae and eyes, and use their sensory forelegs to navigate their environment.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Antennae are primary sensory structures in hexapods.
However, some primitive, soil-dwelling entognathous hexapods lack antennae and have developed alternative sensory adaptations.

Step 2: Detailed Explanation:
Let us review the presence of antennae in the groups listed:
1. Mallophaga (A): Biting lice possess reduced, short antennae that are often held in grooves on the head, but they are present.
2. Diplura (B): Primitive entognathous hexapods that possess long, segmented, moniliform antennae.
3. Anoplura (C): Sucking lice possess short, 3- to 5-segmented antennae used to navigate host hair or feathers.
4. Protura (D): These are primitive, soil-dwelling entognathous hexapods.
They are unique among hexapods in completely lacking antennae and compound eyes.
To compensate for the loss of antennae, proturans hold their modified forelegs forward while walking.
These forelegs contain numerous sensilla and function as sensory organs, effectively replacing the sensory role of antennae.

Step 3: Final Answer:
Therefore, antennae are absent in the order Protura.