Question

Male and female cockroaches can be distinguished externally through
(a) Anal styles in male
(b) Anal corsi in female
(c) Anal style and antennae in females
(d) Both A and C

Answer 1

Hint: In cockroaches, males bear a pair of short, thread-like structures present at the posterior region, which are absent in females.

Complete answer: Male and female cockroaches can be distinguished externally through anal style, which is present only in males and absent in female Cockroaches. It is thin, paired with an unjointed outgrowth project backwardly from the sides of the 9th sternum of male cockroach. Anal styles is male sex structure which helps in intercourse. This is a thread-like structure found in arthropods. In contrast to this anal cerci is found in the females.

So, the correct answer is ‘Anal styles in male’.

Additional Information: Male and female cockroaches are generally distinguished externally by the dimensions.

Male Cockroach	Female Cockroach
A male cockroach is smaller in size	A female cockroach is larger in size compared to a male cockroach
The wings of the male cockroach are larger.	The wings of the female cockroach are smaller.
The antennae of male cockroaches are smaller than that of the females.	The antennae are relatively larger than that of the males.
In male, the sternum of mesothorax is not bifurcated	In females, the sternum of mesothorax is bifurcated.

Cockroaches are around for many years, evolving into a number of the foremost adaptable pests on Earth. There are around 4,000 living species of cockroaches present in the world.
Cockroaches are comparatively primitive, they have only three stages in their life cycle that is egg, nymph, and adult.
Note: A cockroach can survive for a week without its head this is because of their open cardiovascular system, and therefore the incontrovertible fact that they breathe through little holes in each of their body segments, they are not dependent on the mouth or head to breath. Cockroaches can live without food for one month. They prey on human food and they spread germs that cause disease.