Question

Given below are two statements:
Statement (I): Methoprene, Hydroprene and Fenoxycarb are juvenile hormone analogue
Statement (II): Juvenile hormone analogue do not kill the insect but prevent the development of the larval stages
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:

JHAs are categorized as third-generation insecticides. They are highly selective because they target physiological pathways unique to arthropods, making them safe for non-target vertebrates.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Insect Growth Regulators (IGRs) are biorational insecticides that mimic or disrupt naturally occurring hormones.
The main insect development hormones are juvenile hormone (JH) and ecdysone.
Juvenile Hormone Analogues (JHAs) copy the action of natural JH, which keeps the insect in its immature (larval/nymphal) state.

Step 2: Detailed Explanation:
Let us analyze both statements:
Statement (I):
Methoprene, hydroprene, and fenoxycarb are chemically synthesized molecules designed to bind to the juvenile hormone receptors of insects.
They are widely used in pest control programs to target domestic and public health pests.
Methoprene is commonly used against mosquito larvae and fleas, hydroprene is utilized against cockroaches, and fenoxycarb acts against ants and scale insects.
Thus, Statement I is factually correct.
Statement (II):
JHAs have low acute toxicity and generally do not kill the targeted insect immediately upon contact.
Instead, they disrupt metamorphosis and development.
By maintaining high levels of juvenile hormone activity when the insect should naturally transition to pupation or adulthood, JHAs prevent successful molting, pupation, or sexual maturation.
This results in malformed, sterile adults or individuals that die during developmental transitions.
Because they prevent normal larval development and disrupt reproduction rather than acting as fast-acting poisons, Statement II is also correct.

Step 3: Final Answer:
Both Statement I and Statement II are correct, making Option 1 (or A) the correct choice.