Question

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 boat shaped sternum on the ninth abdominal segment
• D. Presence of anal cerci

Answer 1

The correct option is B Presence of caudal styles

Males bear a pair of short, thread-like anal/caudal styles which are absent in females and this is the feature which identifies the male from the female cockroach.

In females, the 7th sternum is boat-shaped and together with the 8th and 9th sterna forms a brood or genital pouch. This is the feature which identifies a female from a male cockroach.

In both sexes, the 10th segment bears a pair of jointed filamentous structures called anal cerci.

In both sexes, the forewings arising from the mesothorax are dark, opaque, leathery and are called tegmina.