Biological control component is central to
advanced agricultural production. Which of the
following is used as a third generation pesticide?
(a) Insect repellants
(b) Pheromones
(c) Pathogens
(d) Insect hormone analogues
Answers
Answer:
d)insect hormone analogues
Explanation:
Insect hormones, i.e. pheromones, are third generation pesticides. Pheromones are the chemical substances which when released into an animal's surroundings, influence the behaviour or development of other individuals of the same species.
Answer:
The first-generation pesticides, which were used prior to 1940, consisted of compounds such as arsenic, mercury, and lead. These were soon abandoned because they were highly toxic and ineffective. The second-generation pesticides were composed of synthetic organic compounds.
Insect hormone analogues are used as a third generation pesticide. These are far superior to the lead arsenate and DDT that epitomize the two earlier generations. These chemicals, called as juvenile hormones, are made in two small glands in insect's heads. Juvenile hormone must be secreted at certain stages in an insect's life and not secreted at other times.
A pathogen is anything that causes a disease.
A pheromone is a chemical an animal produces which changes the behavior of another animal of the same species (animals include insects). Some describe pheromones as behavior-altering agents. Many people do not know that pheromones trigger other behaviors in the animal of the same species, apart from sexual behavior.
Insect repellant is a substance applied to skin, clothing, or other surfaces which discourages insects (and arthropods in general) from landing or climbing on that surface.
Therefore, the correct answer is option D.