This document summarizes a seminar presentation on insect growth regulators (IGRs). It defines IGRs as compounds that interfere with insect growth and development, preventing reproduction. The presentation covers the natural hormones that regulate insect growth, including juvenile hormone, ecdysone, and brain hormone. It then discusses classes of IGRs like chitin synthesis inhibitors, juvenile hormone analogs, and moulting hormone analogs. Examples are given of both natural and synthetic IGR products. The advantages of IGRs in integrated pest management are their specificity, safety, and slower development of resistance.

1. Presented by,
Seminar – I (ENT-649) Date : 07/03/19
MRINMOY MAHANTY
M.Sc.(Ag.)Entomology,3rd Semester
Department of Agricultural Entomology
Faculty of Agriculture
Bidhan Chandra Krishi Viswavidyalaya
Mohanpur, Nadia, West Bengal, Pin: 741252
Chairman,
Dr. Sudarshan Chakraborty
Seminar Leaders
Prof. Santanu Jha &
Dr. Kushal Roy

2. INTRODUCTION
 Insect growth regulators are the compounds which
interfere with the growth and development,
 Insect cannot reach adulthood, and can’t reproduce.
The insect or the whole insect population may die
eventually.
They act on insects, compared with most conventional
insecticides.
IGR is a short form of “birth control” for pests.

3. Growth Regulation of Insects?
 Growth regulation is a natural and normal process of
insects which controlled by certain natural hormone
viz., Brain hormone, Molting hormone, Juvenile
hormone.
1. Brain hormone:
 Also called activation hormone(AH).
 It is secreted by neuro secretory cells (NSC).
 It’s activate the corpora allata to produce juvenile
hormone(JH).

4. 2. Juvenile hormone (JH):
 Also called neotinin.
 It is secreted by corpora allata .
 keep the larva in juvenile condition & development of
genitalia in adults.
3. Ecdysone :
 Also called Moulting hormone (MH).
 It is secreted by Prothoracic Glands (PTG).
 Its main function is moulting in insects.
(http://eagri.org/eagri50)
Contd…..

5. IGR ?
Insect growth regulator is a chemical (natural or
synthetic) which affect the growth and
development of insects.

6. Role of IGRs
IGRs typically work by mimicking or inhibiting
the juvenile hormone (JH).
These can also act on eggs, causing sterility, disrupting
behavior or diapause, the process that causes an insect
to become dormant before winter.
IGRs that inhibit JH production can cause insects to
prematurely molt into a nonfunctional adult.
IGRs that inhibit ecdysone can cause pupal mortality
by interrupting the transformation of larval tissues into
adult tissues during the pupal stage. (Krysan et al.,2010.)

7. Brief History And Development Of Insect
Growth Regulators
 1956 - The first account of the potential use of IGRs in
insect control. (Hasan and Nedim, 2004.)
 1968 - Discovery of methoprene, hydroprene and
kinoprene.
 1970 - Develop and produce new IGR products for flea
control (Precor ).
 1975 - Methoprene was first registered by EPA as a
conventional, chemical pesticide.
 1979 - The first ever application of an IGR (Diacon)as a
crop protectant, against cigarette beetles in stored
tobacco. (https://www.ncbi.nlm.nih.gov/books.)
 1980 - IGRs first appeared on the market.
(Robert and Frederick 2010.)

8. Contd…….
 1982 - “EPA” issued a Registration Standard for
Methoprene.
 1983 - The “ZRD” helped for lead to the development
of the hydroprene (Gentrol). (https://www.ncbi.nlm.nih.gov/books)

9. Principle Of IGRs Control
Aim at studying the growth & development
(metamorphosis) and reproduction regulating
chemicals and exploiting them for preventing pest
population.

10. Classification of IGRs
Insect growth Regulators
Natural Synthetic
Anti- juvenile hormone agents
Juvenile hormone analoges
Chitin synthesis inhibitors
Moulting hormone analoges

11. Natural Insect Growth Regulators
 Commonly used natutal IGRs are – Azadirachtin,
Plumbagin etc.
• Leaf and seed extract of Azadirachta indica.
• The mode of action of azadirachtin at the
cellular level.
• It is effect on behaviors through
chemoreceptory mechanisms.
• Its involved in the control of yolk
deposition in the eggs, moult disruption,
moulting defects and sterility effects.
• Chemical formula : C35H44O16
Azadirachtin

12. Contd…..
• Target Order : Lepidoptera,
Hemiptera, Thysanoptera,
Diptera, Orthoptera, Coleoptera
etc.
• Successful Example : Gypsy
moths, Fall armyworms, Cabbage
butterfly, Desert locust,
Helicoverpa armigera, khapra
beetle, Flea beetle, Oriental
fruitfly, Mediterranean fruitfly,
Rice gall midge, House mosquito,
Whitefly, Mealybug etc.
(Mordue and Blackwell, 1993)

13. Market Available Products
Neemoz Gold, Neemoz
platinum, Mahaneem,
MargoSom 0.03%, Azatin,
Azardin, NeemixOG etc.
Contd…..

14. • Roots extract of the plant
genus Plumbago.
• Effects in moulting process,
ecdysial failure and blockage of
adult emergence.
• Chemical Formula :- C11H8O3
•Successful example :- Pericallia
ricini , Dysdercus koenigii etc.
Plumbagin
(Gnanamani and Dhanasekaran., 2013)

15. List of some other Natural IGRs
Chemical Name Source Successul Example
Limonoid (sendanin) Trichilia roka (Fruits) Heliothis virescens ,
Spodoptera frugiperda,
H. zea etc.
Simple ketone, 5-ocimenone Tagetes minuta (Leaves) Dysdercus koenigii
Echinacein Echinacea angustifolia
(Roots)
Tenebrio molitor ,
Onchopeltus fasciatus etc.
Ethanolic extract Custard apple, Annona
reticulata , A. glabra (Fruit)
Diabrotica sp. etc.
Clerodane Ocimum basilicum (Leaves) Culex mosquitoes,
Oncopeltus fasciatus etc.
Ajugarin Ajuga reptans L . A. remota Mexican bean beetle, two-
spotted spider mite, beet
armyworm,
Contd…..
(Jacobson,M.,1986)

16. Synthetic Insect Growth Regulators
Chitin synthesis inhibitors
• CSIs prevent the formation of chitin.
• During moulting there is improper
attachment of new cuticle, that lacks
some of the layers normally occur.
• BPU analogues block the terminal
polimerization step catalyzed by chitin
synthase.
• Thiadizine compound (buprofezin)
inhibit incorporation of glucose and N-
acetyl- glucosamine.

17. Glucose
N- Acetyl Glucosamine – 1p
UDP – N – Acetyl
Glucosamine Phosphorylase
UDP – N – Acetyl Glucosamine
(GLcNAc)n Chitin synthase
Chitin (GLcNAc)n+1
Chitin (GLcNAc)n-1
Chitinase
+ Chitobiose (GLcNAc)2
Chitobiase
2GLcNAc
Fig : Biosynthetic Pathway of chitin synthesis
Contd…..

18. Market Available Product
Name of
the IGRs
Molecular
Formula
Target Order Successful
Example
Product
available in
market
Diflubenzuron C14H9CIF2N2O2 Lepidoptera,
Coleoptera, Diptera etc.
Gypsy moths, Housefly,
Boll weevil etc.
Larvakil, Dimilin,
Difluron, Astonex
etc.
Lufenuron C17H8Cl2F8N2O
3
Lapidoptera,
Coleopteratc.
Armyworm, Codling
moth, vegetable beetles
etc.
Lunox, Match etc
Novaluron C17H9ClF8N2O4 Lepidoptera, Diptera,
Hemiptera etc.
Helicoverpa armiera ,
Spodoptera litura ,
Liriomyza trifoli etc.
Rimon, Biltora,
Rimostar, etc
Teflubenzuron C14H6Cl2F4N2O
2
Lepidoptera,
Hemiptera, Coleoptera,
Diptera etc.
Whitefly, jumping plant
lice, Codling moth etc.
Nemolt, Nomolt,
Tefluron, Dart etc.
Chlorfluazuron C20H9Cl3F5N3O
3
Coleoptera, Hemiptera,
Thysenoptera,
Lepidoptera etc.
Rhyzopertha dominica,
Sitophilus oryzae,
Whitefly, Thrips etc.
Atabron, Helix,
Aim, Jupiter etc.
Buprofezin C16H23N3OS Hemiptera BPH, Whitefly etc. Himbupro, Bullet,
Banzo, Apollo etc.
Contd….

19. Juvenile Hormone Analogues
 “Carrol Williams “(1967) proposed that, the insect juvenile
hormone (JH) as an insecticide.
 JHAs cause wide range of developmental derangement in
susceptible species.
 It affect embryogenesis, laval development, metamorphosis and
reproduction.
 The exogenous appication of JHAs to insects results in the
formation of supernumerary nymphal/larval inster, larval- pupal,
pupal- adult intermediates.
 JHAs application to adult females or eggs results in ovicidal and/ or
chemosterilizing effects.

20. Market Available JHAs Products
Name of
the IGRS
Molecular
Formula
Target Order Successful Example Market
Available
Products
Methoprene C19H34O3 Siphonaptera,
Hymenoptera,
Coleoptera,
Lepidoptera,
Diptera etc.
Flea, Mosquitoes and several
types of Ants, Lice, Moths,
Beetles etc.
Altosid, Precor,
Apex, Diacon,
Dianex, Kabat,
Minex, etc.
Pyriproxyfen C20H19NO3 Hemiptera,
Diptera,
Dictyopotera,
Lepidoptera, etc.
Houseflies, Mosquitoes,
Cockroaches ,Whitefly,
Jassids, Aphids, Bollworm,
Cutworms etc.
Daita
Fenoxycarb C17H19NO4 Diptera,
Siphonaptera,
Dictyoptera,
Hymenoptera,
Lepidoptera, etc.
Mediterranean fruit flies,
Mosquitoes, Fire ants, Fleas,
Cockroaches etc.
Award, Logic,
Insegar, Pictyl,
Comply, Torus etc.
Diofenolan C18H20O4 Lepidotera,
Hemiptera etc.
Citrus butterfly ,
Spodoptera litura, Scale
insects etc.
Aware.
Contd…..

21. Market Available JHAs
Name of
the IGRS
Molecular
Formula
Target
Order
Successful Example Market
Available
Products
Hydroprene C17H30O2 Lepidoptera,
Coleoptera,
Dictyoptera,
etc.
Cockroaches, Beetles, moths
etc.
Gencor, Gentrol,
Discs, Sterilizer
etc.
Kinoprene C18H28O2 Hemiptera Aphids, Mealybugs, Whiteflies,
Armoured scales etc.
Enstar
Triprene C18H32O2S Hemiptera,
Lepidoptera,
Orthoptera etc.
Soft scale insects, Aphids,
Cotton leafworm, Pink
bollworm, Dessert
locust etc.
Altorick
Epofenonane
C20H32O2
Lepidoptera,
Hemiptera etc.
Fruit tree leafrollers; Aphids,
Psyllids, Whitefly , Scale
insects etc.
Contd…..

22. Anti-juvenile hormone agents
 It is also known as Precocenes.
 Anti-juvenile hormone agents act by destroying
corpora allata and preventing JH synthesis.
 When treated on immature stages of insect, they skip
one or two larval instars and turn into tiny precocious
adults. They(adults) can neither mate, nor oviposit
and die soon.
 Eg. – EMD (ethyl (E)-3-methyl-2-dodecenoate),
Fmev (Fluoromevalonate), and PB (Piperonyl
Butoxide) etc.

23. Moulting hormone analogues
 MHAs blocking the biosynthesis of moulting hormone
and disrupt moulting process.
When applied in insects, kill them by formation of
defective cuticle. The development processes are
accelerated bypassing several normal events resulting in
integument lacking scales or wax layer.
 It also affect in egg production and spermatogenesis
in adults.

24. Market Available MHAs Products
Name of the
IGRS
Molecular
Formula
Target
Order
Successful Example Market
Available
Products
Tebufenozoid C22H28N2O2 Lepidoptera Codling moth, Gypsy
moth, Fruit tree leaf
folder etc.
Mimic,
Confirm etc.
Halofenozoid C18H19ClN2O
2
Coleoptera,
Lepidoptera
etc.
Scarabaeiid beetle,
Oriental beetle,
Japanese beetle,
Cutworm, Webworm
etc.
MACH 2,
GrubEx etc.
Methoxyfenozoid C22H28N2O3 Lapidopteran
pest of fruits
& vegetable
Lesser appleworm,
Oriental fruit moth,
Loopers, Armyworm,
Bud moths
Intrepid
Runner
Prodigy
Falcon
Contd…..

25. Advantage of IGRs
 Effective in minute quantities and so are economical.
 Target specific and so safe to natural enemies.
 Bio-degradable, non-persistent and non-polluting.
 Non-toxic to humans, animals and plants.
 Well fitted into IPM programme.
 Less chance to resistance.
(http://eagri.org/eagri50)

26. Disadvantage of IGRs
 Kills only certain stages of pest.
 Slow mode of action.
 Not easily available.
 High Cost.
 Unstable in the environment. (http://eagri.org/eagri50)

27. Conclusion
 At present IGRs play a limited role in overall pest
managemet.
 There is a need for fundamental research on
controlled release system, which are cheaf,
non toxic and biodegradable and developed the
suitable application technology.
 The IGRs are becoming more reliable and look set
for a promising future in IPM programme.

28. Reference
• http://eagri.org/eagri50/ENTO232/lec23.pdf
• Krysan, James; Dunley, John. "Insect Growth Regulators". Retrieved 20
November 2010.
• Hasan T, Nedim U, Turk J Agric For, 2004, 28, 377.
• https://www.ncbi.nlm.nih.gov/books/NBK234642/#NBK234642_footnotes
• Robert H. Poppenga, Frederick W. Oehme, in Hayes' Handbook of
Pesticide Toxicology (Third Edition), 2010.
• Mordue (Luntz), A.J. & A. Blackwell., 1993. Azadirachtin: An update. J.
Insect Physol. 39: 903-924.
• Gnanamani.R. and Dhanasekaran.S. 2013, Insect Growth Regulator
Plumbagin from Plumbago indica Against Pericallia ricini (Lepidoptera:
Aractidae), Asian Journal of Plant Sciences Volume 12 (5): 219-223.
• Srivastava, K.P. and Dhaliwal G.S., “A Textbook Of Applied Entomology”
(Third Edition), 2010.