Match List I with List II, select the correct answer using the codes given in the options :

	List I		List II
(a)	First Generation Pesticides	1.	Pheromones
(b)	Second Generation Pesticides	2.	Juvenile Hormones
(c)	Third Generation Pesticides	3.	Pyrethrins
(d)	Fourth Generation Pesticides	4.	Organo phosphates

The correct answer is (a) - 3, (b) - 4, (c) - 1, (d) - 2.

Key Points

• Pyrethrins
  • They are a class of organic compounds.
  • It is normally derived from Chrysanthemum cinerariifolium, which targets the nervous systems of insects.
  • Pyrethrin occurs in chrysanthemum flowers naturally.
  • It is often considered an organic insecticide when it is not combined with piperonyl butoxide.
• Organo phosphates
  • They are a class of organophosphorus compounds with the general structure O=P (O double bond P).
  • It is considered an ester of phosphoric acid.
  • They are commonly used as flame retardants, plasticizers and additives to engine oil.
  • It is also used in industries such as textiles and furniture.
• Pheromones
  • It is an excreted chemical factor that triggers a social response in members of the same species.
  • They are chemicals that act like hormones outside the body of the secreting individual.
  • There are many types of pheromones, such as
    • alarm pheromones
    • food trail pheromones
    • sex pheromones
• Juvenile Hormones
  • They are a group of acyclic sesquiterpenoids.
  • It regulates many aspects of insect physiology.
  • Vincent Wigglesworth discovered Juvenile Hormones.
  • These hormones regulate development, reproduction, diapause, and polyphenisms.
  • Juvenile Hormones were formerly called neotenin.
  • These hormones are secreted by a pair of endocrine glands behind the brain known as corpora allata.

Additional Information