A useful insect which no longer occurs in wild is

Options

A. Laccifera indica
B. Drosophila melanogaster
C. Musca nebulo
D. Bombyx mori

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a useful insect that no longer occurs in the wild. This means we need to identify an insect that has been completely domesticated and is not found in its natural habitat anymore.

2. **Analyzing the Options**:
- **Lassifera indica**: This insect is not widely recognized and does not fit the criteria of being a useful insect that is no longer found in the wild.
- **Drosophila melanogaster**: Known as the fruit fly, this insect is commonly found in wild conditions and is used in genetic studies. Therefore, it does not meet the criteria.
- **Musca nibullo**: This option refers to a type of fly that can be found both in domestic and wild conditions, making it an incorrect choice.
- **Bombix mori**: This is the scientific name for the silkworm. It was originally a wild insect but has been completely domesticated for silk production and is no longer found in the wild.

3. **Conclusion**: After analyzing all the options, the only insect that fits the description of being useful and no longer occurring in the wild is **Bombix mori** (the silkworm).

**Final Answer**: The useful insect which no longer occurs in the wild is **Bombix mori**.

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