Which one of the following species of earthworm is not recommended for vermicomposting

Options

A. Eudrilus eugeniae
B. Eisenia fetidae
C. Pyronyx excavatus
D. Pheretima posthuma

Answer

To determine which species of earthworm is not recommended for vermicomposting, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Vermicomposting**: Vermicomposting is a process that uses earthworms to convert organic waste into nutrient-rich compost. Not all earthworm species are suitable for this process.

2. **Classify Earthworms**: Earthworms can be classified into two main categories:
- **Humus Formers**: These species are effective in vermicomposting as they can convert organic waste into humus.
- **Humus Feeders**: These species do not convert organic waste into humus and are therefore not suitable for vermicomposting.

3. **Identify the Species**: The question provides four species of earthworms:
- Eudrilus eugenii
- Eudrillus eugeniae
- Pheretima posthuma
- Perionyx excavatus

4. **Determine Their Classification**:
- **Eudrilus eugenii**: This species is a humus former and is suitable for vermicomposting.
- **Eudrillus eugeniae**: This species is also a humus former and suitable for vermicomposting.
- **Pheretima posthuma**: This species is classified as a humus feeder and is not suitable for vermicomposting.
- **Perionyx excavatus**: This species is a humus former and is suitable for vermicomposting.

5. **Conclusion**: Since Pheretima posthuma is the only species classified as a humus feeder, it is the one that is not recommended for vermicomposting.

### Final Answer:
The species of earthworm that is not recommended for vermicomposting is **Pheretima posthuma**.

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