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

Options

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

Explanation

To identify a male cockroach from a female cockroach, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Sexual Dimorphism**:
- Cockroaches exhibit sexual dimorphism, meaning that male and female cockroaches have distinct physical characteristics that allow us to differentiate between them.

2. **Examining the Body Structure**:
- A cockroach's body is segmented into three main parts: the head, thorax, and abdomen. Both male and female cockroaches have these segments, but they differ in some features.

3. **Analyzing the Options**:
- **Option A**: Four wings with darker tegmina.
- Both male and female cockroaches have two pairs of wings (forewings and hindwings), and these do not differ significantly between sexes. This option is not useful for differentiation.

- **Option B**: Presence of caudal style.
- The caudal style (or anal style) is a pair of thread-like structures found only on the male cockroach's 10th abdominal segment. This feature is absent in females, making it a distinguishing characteristic.

- **Option C**: Broad-shaped sternum on the 9th abdominal segment.
- The broad-shaped sternum is actually found on the 7th abdominal segment of females, forming a genital pouch. This feature is not useful for identifying males.

- **Option D**: Anal saccae.
- Anal saccae are present in both male and female cockroaches, so this option does not help in distinguishing between the sexes.

4. **Conclusion**:
- The only feature that can be used to identify a male cockroach from a female cockroach is the presence of the caudal style (anal style). Therefore, the correct answer is **Option B**.