Question

Mouth of a cockroach are placed in a downward arrangement with a smaller upper lip and a larger lower lip. This arrangement is called .

• A. opisthognathous
• B. hypognathous
• C. prognathous

Answer 1

The correct option is B hypognathous

The arrangement of mouthparts in an insect is very dynamic and is dictated by the feeding habits of the particular insect.

1. Hypognathous: The long axis of the head is vertical i.e. at right angles to the long axis of the body. The mouthparts point downwards e.g. grasshopper, cockroach etc.

2. Prognathous: The long axis of the head is horizontal and in line with the long axis of the insect's body. The mouthparts are directed forward. e.g., stick insect, soldier caste of termites etc.

3. Opisthognathous: The head is reflexed ventrally so that the mouthparts are directed backwards between the coxae of the front legs. e.g., red cotton bug.