RECENT METHODS OF PEST CONTROL
Recent methods of pest control
includes following agents
B. Insect Attractants
C. Insect Repellants
D. Genetic Control/Autocidal Control
E. Insect Growth Regulators
These are the chemical substances that inhibit
feeding of insects when applied on the foliage
without impairing their appetite and gustatory
receptors or driving them away from the food.
They are also called Gustatory repellants/ Feeding
deterrents / Rejectants.
Since insects do not feed on treated surface, they
die due to starvation.
MODE OF ACTION
They inhibit gustatory (taste) receptors of the
GROUPS OF ANTIFEEDANTS
B. Organotins :- Compounds having tin
eg:-Triphenyl tin acetate
C. Carbamates :- Sub-lethal doses of
D. Botanicals :- Anti-feedants from non-host
∙Pyrethrum- From C. cinerarifolium
.Solanum alkaoids- Leptine, Tomatine & Solanine
Affects plant feeders
but safe to N.E.
Pests are not killed
immediately so N.E.
can feed on them
Not effective for
Not effective as sole
B. INSECTS REPELLENTS
Chemicals which cause insects to move away
from their source are referred to as repellents (or)
Chemically that prevent insect damage to plants
(or) animals by rendering them unattractive,
unpalatable (or) offensive are called repellents.
Mode of Action:- Influences both gustatory &
C. INSECTS ATTARACTANTS
Chemicals that cause insects to make oriented
movements towards their source are called insect
Mode of Action:- It influences both gustatory and
TYPES OF ATTARACTANTS
1. Pheromones:-Chemical that is secreted into the external
environment by an animal and that elicits a specific response
in a receiving individual of the same species.
2. Food Lures:-These are Chemicals present in plant and animal
hosts that attract (lure) insects for feeding. They stimulate
3. Oviposition Lures:-These are chemicals that govern the
selection of suitable sites for oviposition by the adult female
eg:-Corn attaractants for H. armigera
4. Poison Baits:-Poison baits are a mixture of food lures and
insecticides. The effort is made to make the bait more
attractive to insects than their natural food and also a smaller
quantity should be able to attract the largest number of
Doesn’t disrupt eco-
Can be used for
Do not cause
Insects can always
find untreated hosts
It is not a sole source
of insect control
Semiochemicals:- They are chemicals that mediate
communication between organisms.
It is classified into two groups:-
i. Pheromones:- Intra-specific
ii. Allelo-chemicals:- Inter-specific
--Pheromones are also called Ectohormones.
--The term “pheromone” was given by Karlson and
Butenandt in 1959 when they identified it in Silkworm
Primer pheromones:- A chain of physiological changes
is triggered off in the receiving animal. They act on
eg:-Caste discrimination & reproduction in social
Releaser pheromone:-An immediate and reversible
behavioural change is produced in the receiving
i. Sex Pheromone
ii. Aggregation Pheromones
iii. Trail Pheromones
Aphrodisiacs:- These are substances that aid in courtship
of the insects after two sexes are brought together. In many
cases, male produce aphrodisiacs.
Calling position:- The posture shown by the female during
the pheromone release.
Mono-component pheromone system:- If a pheromone
consists of only one chemical compound.
Multi-component pheromone system:- If a pheromone
consists of more than one chemical compounds.
Use of Sex pheromones in Pest management
ii. Mass trapping
iii. Confusion or Decoy method
D. GENETIC INSECT
A) Induced Sterility
i) Sterile male release technique: When a sterile male mates with
normal female there will be no progeny.
-This theory of Male Sterile Technique was conceived by
E.F. Knipling as early as 1937.
ii) Aspermia: Inactivation of sperms.
iii) Infecundity: Sterile eggs by dominant lethal mutation.
B) Cytoplasmic Incompatiblity: Sterility is due to a cytoplasmic
factor transmitted through the egg, which kills the sperm of
incompatible male after its entry into the egg.
C) Hybrid Sterility: In some insect cross-types or races which
produce fertile females but sterile males among progeny.
D) Population replacement: The ability of disease
of vectors i.e. replacement of specific vector populations
as well be changed by genetic methods.
E) Autosterilization: Sterilization of native insects in their
natural environment by using chemosterilants along with
the species specific attatractants / lures/ bait traps.
-Bonus effect: The sterile males mates with the normal
females thus reduces reproductivity.
METHODS OF STERILIZATION
i. Alkalyting agents: They inhibit nucleic acid
synthesis, inhibits gonad development & produce
Eg:- TEPA, Chloro ethylamine etc.
ii. Antimetabolites: Chemicals with structural
similarity with biological substances.
Eg:- 5-Fluororacil, Amethopterin etc.
B. Irradiations: It is done by exposing the insects to X-
rays or neutrons emitted from Cobalt.
E. INSECT GROWTH
IGRs are compounds which interfares with the
growth, development and metamorphosis of
1.Ecdysone or Moulting Hormone (MH):Synthetic
analogues of ecdysones are called ecdysoids
- It causes defective cuticle formation.
2. Juvenoids: The possibility that JH analogs may have
potential as insect control was first recognized by
Williams & Slama (1966). The compounds showing JH
-They found it in paper made of Balsam fir tree.
3.Anti JH or Precocenes: Precocenes are the compounds
which would antagonize the JH activity and de-arrange the
insect development. These compounds induce the
precocious metamorphosis of immature insects.
Precocenes affect insect diapause, reproduction and
behaviour. These compounds first extracted from the plant
4.Chitin synthesis inhibitors: Chitin synthesis inhibitors disrupt
molting by blocking the formation of chitin, the building block
of insect exoskeleton. Without the ability to synthesize chitin,
molting is incomplete, resulting in malformed insects that soon
die. It suppresses egg-laying and causes egg sterility in treated
adults through secondary hormonal activity
Eg:-Diflubenzuron, Flufenoxuron etc.