How much percentage of all insects are phytophagous which feeds on plant sap and other plant part ?

Answer

To solve the question regarding the percentage of phytophagous insects that feed on plant sap and other plant parts, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition**:
- Phytophagous insects are those that primarily feed on plants. This includes their sap and various parts such as roots, stems, leaves, and flowers.

2. **Identify the Total Insect Population**:
- To determine the percentage of phytophagous insects, we need to consider the total number of insect species.

3. **Determine the Percentage of Phytophagous Insects**:
- According to the information provided, it is stated that 25% of all known insects are phytophagous.

4. **Conclusion**:
- Therefore, the answer to the question is that 25% of all insects are phytophagous, meaning they feed on plant sap and other plant parts.

### Final Answer:
**25% of all insects are phytophagous.**

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