2018 Structural Organisation in AnimalsCockroach – sexual dimorphism Medium Question 45 of 92 in Structural Organisation in Animals

Which of the following features is used to identify a male cockroach from a female cockroach?

A Forewings with darker tegmina
B Presence of caudal styles
C Presence of a boat shaped sternum on the $9^{th}$ abdominal segment
D Presence of anal cerci

The answer is B.

Solution

Only male cockroaches have anal (caudal) styles.

Males bear a pair of short, thread-like anal styles which are absent in females. Anal/caudal styles arise from the $9^{th}$ abdominal segment in the male cockroach.

Concept cockroach-anal-styles

Structural Organisation in Animals in past papers

92 questions from this chapter have appeared across 26 exam years.