The labium in cockroach is formed by

Options

A. first maxillae
B. second maxillae
C. mentum
D. submentum

Answer

To answer the question "The labium in cockroach is formed by?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Labium**:
- The labium is a part of the mouth structure in cockroaches. It plays a crucial role in the feeding process, specifically in biting and chewing food.

2. **Identifying the Components of the Labium**:
- The labium is formed by the fusion of certain mouthparts. In insects, the mouthparts are typically categorized into various structures, including maxillae and labium itself.

3. **Analyzing the Options**:
- **Option A: 1st maxillae** - This is not correct as the labium is not formed by the first maxillae.
- **Option B: 2nd maxillae** - This is a strong contender since the labium is indeed formed by the fusion of the second maxillae.
- **Option C: Mentum** - The mentum is part of the labium but does not solely form it.
- **Option D: Submentum** - Similar to mentum, it is part of the labium structure but does not constitute its formation.

4. **Conclusion**:
- Based on the analysis, the labium in cockroaches is formed by the second maxillae. This fusion creates what is referred to as the "second lip" in cockroaches.

5. **Final Answer**:
- Therefore, the correct answer is **Option B: 2nd maxillae**.