Ladybird is useful to get rid of

Options

A. Bollworms
B. Aphids
C. Mosquitoes
D. Nematodes

Answer

### Step-by-Step Solution

1. **Identify the Subject**: The question asks about the usefulness of ladybirds in controlling pests.

2. **Understand What Ladybirds Are**: Ladybirds, also known as lady beetles or ladybugs, are beneficial insects that play a role in agriculture.

3. **Identify the Pests**: The options given are:
- A) Ballworms
- B) Aphids
- C) Mosquitoes
- D) Nematodes

4. **Research the Pests**:
- **Ballworms**: These are caterpillars that can damage crops but are not primarily targeted by ladybirds.
- **Aphids**: These are small insects that suck nutrient-rich liquids from plants, leading to crop damage.
- **Mosquitoes**: These are not typically associated with crop damage and are not controlled by ladybirds.
- **Nematodes**: These are microscopic worms that can affect plants but are not the primary target of ladybirds.

5. **Determine the Correct Answer**: Since ladybirds are known to feed on aphids, which are harmful to plants, the correct answer is **B) Aphids**.

6. **Conclusion**: Ladybirds are beneficial insects that help control aphid populations, thereby protecting crops from damage.