Question

Third generation pesticides are
A) Pheromones
B) Juvenile hormone analogues
C) Insect repellents
D) Pathogens

Answer 1

Hint:Pesticides are any chemical substance or material, including insects, rodents, fungi and unwanted weeds, able to prevent pests. It is also used in public health to kill disease vectors, such as mosquitoes, and in agriculture, to kill crop-damaging pests.

Complete answer
To answer this question, we should know details about pesticides. Pesticides can be classified into four generations viz. first, second, third, and fourth.

Pesticides of the third generation are essentially altered insect hormone types that aim to provide the insecticides that are not only more effective, but also evidence against the creation of resistance. Mimics of juvenile hormones such as methoprene and hydroprene do not directly kill the bee, but prevent its larvae from developing.

Carroll M. Williams (1956) was perhaps the first to identify the capacity for the use of insect hormones in the management of insects, and hailed them as third-generation pesticides in 1967; the first generation is evidenced by lead arsenate; the second by DDT.

WiIIiams and Amos (1974) alluded to them as "insect development regulators" while they are now more widely pointed to as "insect growth regulators (IGRs) because it disrupts the normal activity of insects' endocrine or hormone system, affecting the target insect's progress, propagation, or metamorphosis. They slowly reduce the insect's population as the adult insects can never be produced.

Hence the correct answer is option ‘C’.

Note:Terpenoid ethers, epoxidized aromatic ethers, bans, dienoate ethers and non-poxidized dienoates were naturally present juvenile hormones extracted from the tobacco hornworm, Manduca sexta.