Which of the following are natural insecticides?
(a) Rotenone
(b) Pyethrum
(c ) Nicotine
(d) Azadirachtin

Options

A. (a), (b) and & (c ) only
B. (a), (c ) & (d) only
C. (a) & (b) only
D. (a), (b), (c ) & (d)

Answer

To determine which of the following options are natural insecticides, we will analyze each option one by one:

1. **Rotenone**:
- Rotenone is a natural insecticide that is derived from the seeds and stems of certain plants.
- It works by damaging the DNA of the mitochondria in insects, leading to their death.
- Therefore, Rotenone is a natural insecticide.

2. **Pyrethrum**:
- Pyrethrum is obtained from the dried flower heads of the chrysanthemum plant (specifically, Chrysanthemum cinerariifolium).
- The active compounds in pyrethrum are known as pyrethrins, which are esters that target the nervous system of insects, causing paralysis and death.
- Hence, Pyrethrum is also a natural insecticide.

3. **Nicotine**:
- Nicotine is well-known as a natural insecticide that disrupts the neurotransmitters in insects, affecting their nervous system and leading to their demise.
- It is derived from the tobacco plant and is considered an anti-herbivore substance.
- Thus, Nicotine qualifies as a natural insecticide.

4. **Azadirachtin**:
- Azadirachtin is extracted from the seeds of the neem tree (Azadirachta indica).
- It is effective against a wide range of insect pests, destroying around 200 species of insects, including aphids.
- Therefore, Azadirachtin is also a natural insecticide.

After analyzing all four options, we conclude that all of them (Rotenone, Pyrethrum, Nicotine, and Azadirachtin) are natural insecticides.

**Final Answer**: All of the options (a) Rotenone, (b) Pyrethrum, (c) Nicotine, and (d) Azadirachtin are natural insecticides.

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