Blood -sucking insects usually carry parasites in their

Options

A. lungs
B. blood
C. salivary glands
D. tentacles

Explanation

To solve the question "Blood-sucking insects usually carry parasites in their," we need to analyze the options and understand the relationship between blood-sucking insects and the parasites they carry.

### Step-by-Step Solution:

1. **Identify Blood-Sucking Insects**:
- Blood-sucking insects include various species, with the female Anopheles mosquito being a prominent example.

**Hint**: Think about common insects that feed on blood and their role in disease transmission.

2. **Understand the Parasites They Carry**:
- The female Anopheles mosquito is known to carry the parasite Plasmodium, which is responsible for causing malaria in humans.

**Hint**: Recall the diseases associated with blood-sucking insects and the specific parasites involved.

3. **Locate the Parasite's Infective Stage**:
- The infective stage of Plasmodium is known as the sporozoite stage. This stage is crucial for the transmission of malaria.

**Hint**: Consider how parasites are transmitted from insects to humans and where they are stored in the insect’s body.

4. **Identify Where the Parasite is Found in the Insect**:
- The sporozoites of Plasmodium are located in the salivary glands of the female Anopheles mosquito.

**Hint**: Think about the mechanism of transmission and the anatomical structures involved in the process.

5. **Conclusion**:
- When a female Anopheles mosquito bites a human, it injects saliva containing the sporozoites into the bloodstream, leading to infection. Therefore, the correct answer to the question is that blood-sucking insects usually carry parasites in their **salivary glands**.

**Final Answer**: The correct option is **salivary glands**.