Question

Given below are two statements
Statement I: Fumigants are used in gaseous form for killing insects
Statement II: Fumigants are liposoluble and mostly used against stored grain insects
In light of the above statements, choose the most appropriate answer from the options given below

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but Statement II is correct

Hint:

Fumigants must act in the gaseous phase to penetrate bulk commodities. Because they are lipophilic, they can easily cross insect cell membranes, making them highly effective against stored grain pests.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Fumigants are specialized chemical pesticides that act in the gaseous phase.
Because they are gases, they can penetrate bulk commodities, soil, and packaging materials to reach pests that are otherwise protected from contact sprays.

Step 2: Detailed Explanation:
Let us analyze each statement individually:
1. Statement I describes the physical state of fumigants.
Fumigants are formulated as liquids or solids that vaporize into gases at ambient temperatures and pressures.
They must be applied in sealed or airtight spaces (such as silos, shipping containers, or under gas-tight sheets) to maintain the required lethal concentration of gas.
Thus, Statement I is correct.
2. Statement II describes the chemical properties and applications of fumigants.
To enter the insect's body, the fumigant gas enters the respiratory system through the spiracles.
Once inside the tracheal tubes, the gas must cross the lipid-rich cellular membranes to reach its target site.
Because fumigants are highly liposoluble (lipophilic), they easily dissolve in and cross these lipid membranes, leading to rapid toxicity.
This high penetrative capacity makes them highly effective for treating stored grains, where pests often live inside the grain mass or within individual seeds.
Thus, Statement II is correct.
Therefore, both statements are correct.

Step 3: Final Answer
Both Statement I and Statement II are correct.