Question

"Flacherie disease" of silkworm is caused by:

• A. Virus
• B. Bacterium
• C. Fungus
• D. Nematode

Hint:

Silkworm diseases:
- Flacherie: Bacterial.
- Grasserie: Viral (NPV).
- Muscardine: Fungal (Beauveria).
- Pebrine: Protozoan (Nosema).

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
This question tests knowledge of silkworm diseases.

Step 2: Detailed Explanation:
Flacherie disease of silkworm is caused by a bacterium (e.g., Bacillus thuringiensis, Streptococcus).
It is a bacterial disease that causes the silkworm to become flaccid and die.
The disease is also associated with viral infection (viral flacherie).
But the primary cause is bacterial.
Virus (A): Causes grasserie (nuclear polyhedrosis).
Fungus (C): Causes muscardine.
Nematode (D): Not a major disease of silkworm.
Thus, flacherie is caused by bacteria.

Step 3: Final Answer:
Thus, flacherie disease of silkworm is caused by a bacterium, which corresponds to option (B).
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