Three main objectives...
Prevention
— keeping a pest to become a problem
Suppression
— reducing pest numbers or damage to an
acceptable level
Eradication
— destroying an entire pest population
Pest control methods...
Legislative control
Cultural
Physical
Biological
Reproductive
Chemical etc.
Legislative control
Control of insect pests by enacting
and enforcing insect laws by the Govt.
Prevent the pest entry from foreign countries
Prevent spread of pests within the country
To enforce control and eradicative measures
Chemicals neither adulterated no r misbranded
Legislative control...
In Pakistan 3 types of legislations to
control either pests or pesticides
Pakistan plant quarantine act 1976
Punjab agricultural pests ordinance 1959
Agricultural pesticides ordinance 1971
Legislative control...
Import of plant or plant material
a. medium of infestation b. pests destrucive to agri-
Plant material with special permit required
a. new varieties b. propagating stock
Penalty
a. Rs. 500/-
b. subsequent offence Rs. 2000/-
or 6 months prision
Salient features of Pakistan plant
quarantine act 1976
Govt. may prohibit
a. cultivation methods b. sale or transport of infested crop
Preventive measures
a. removal of stubbles b. proper sowing time
c. removal of weeds d. avoid ratooning
Penalty
a. Rs. 25,000 to 50,000/-
b. subsequent offence Rs. 50,000 to
100,000/- or 3-6 months prision
Inspection (DGA, DDA and Distt. Agri. Ext. Officers)
Salient features of Punjab agricultural pests
ordinance 1959 and rules 1960
Import and registration of pesticide and distributor
Adulterated importation may be prohibited
Prescribed labelling
Safe storage and use of pesticides
Pesticide labs. for sample analysis
Approved pesticide advertisement
Safety precautions
Penalties for substandard and adulterated pesticides
(5 to 10 lac with 6 months to 3 years imprisonment)
Salient features of Agricultural pesticides
ordinance 1971
Cultural control
Control of Insect pests by performing the regular
agricultural practices
Tillage
Irrigation
Clean seed
Clean culture
Manuring
Pruning and thinning
Trap crops
Resistant varieties
Timing of sowing
Crop rotation
Destruction of
crop residues
Cultural control...
Tillage
The proper stirring and management
of soil can suppress pest population
e.g. surface grasshoppers, field crickets,
beetles and mealy bugs lay eggs in
the upper 5-10 cm of soil
•Seed bed preparation and weed control
•Timing and depth
Cultural control...
Clean seed
Number of insect pests carried from
one crop to next through seeds, cuttings
or other infested plant parts
e.g. hibernating larvae of the pink bollworms
in seeds of cotton (can be killed by
fumigation), fumigation of nursery plants
to protect new orchards from infestation
Cultural control...
Irrigation
By flooding a large number of insects
present in the soil can be drowned or
exposed to natural enemies,
Sprinkler irrigation effective against foliage feeding insects
e.g. lucerne caterpillars can be killed by drowning. sugarcane
and wheat crops can be saved from attack of white-ants
Primarly plant culture activity and
little emphasis given to control
insects by irrigation, except
chemigation
Cultural control...
Manuring
By putting fertilizers in right proportions
make plants healthy and vigorous
e.g. after sugarcane shoots attacked by top-
borer; application of ammonium
sulphate induces tillering.
early sown cucurbits in well manured fields
withstand the attack of red pumpkin beetle
Cultural control...
Clean culture
Removal of all undesired plants,
plant debris and other material from
the field
e.g. undesirable plants in gardens
give protection and provide food
to the newly emerged nymphs of
mango mealy bug
Cultural control...
Time of sowing
By adjusting time of sowing and
harvesting crop can be saved from
infestation
e.g. rice nursery should not sow before 20
May to avoid attack of rice borers.
sugarcane should be harvested before
mid-February to avoid egg-laying of
top borer
Cultural control...
Pruning and thinning
Some pests are carried from old to
new crops, in case of perennial
plants, fruit trees
e.g. proper pruning of undesirable portions
of citrus useful to check the citrus leaf-
miner, citrus red scale etc.
Cultural control...
Trap crops
Sowing of early or parallel in narrow
strips around a major crop; serve as a
trap for pests that might common
e.g. okra is a good trap crop to cotton to
attract jassid and spotted bollworms,
sesame around cotton attract red hairy
caterpillar
Cultural control...
Sowing of resistant
varieties
Certain varieties of crops are tolerant and
less attacked by insect pests than other
varieties
e.g. Gossypium arboreum due to hairiness
character is more resistant to attack of
jassid, whitefly and bollworms. hard
rinded varieties of sugarcane are less
attacked by borers than soft rinded
Cultural control...
Crop rotation
Growing a single crop year after year in the same
field provide continuous supply of food and breeding
facilities; results increase in pest population,
Pest has narrow host range, eggs are laid before the
new crop is planted, the feeding stage is not very
mobile
e.g. okra following a cotton crop increase infestation;
therefore cotton should be rotated with maize, rice,
groundnut etc.
Cultural control...
Destruction of crop
residues
Stubbles of various crops, rice,
sugarcane, maize etc. should be
uprooted and destroyed thoroughly
e.g. sugarcane ratooning provides
protection to root borers, cotton sticks
should be cut below the ground level
to remove stem borers
Physical control...
Reduce of pest population by the
involvement or special manipulation
of physical factors i.e. temperature
and humidity
Hot or cold treatment
Moisture
Light traps
Physical control...
Hot or Cold treatment
Application of heat including exposure to
sun rays during summer helps in killing
pests in seeds and stored commodities
e.g. exposure of cotton seeds to heat helps in
killing diapausing larvae of pink bollworm
treatment of sugarcane setts with heat or
hot water kills scale insects.
cold storage of fruits and vegetables
escape fruit fly, pathogens
Physical control...
Moisture
Insects are highly sensitive to
reduction in moisture
Manipulation of humidity in field
conditions not feasible
e.g. stored grain pests (moisture < 8%)
and greenhouse conditions
Physical control...
Light traps
Light had been used to control many
insects in the form of light traps. Traps
can be used for monitoring pest
population in the area
e.g. several species of moths and beetles
can be attracted to light and killed
Biological control...
Method of controlling pests
using other living organisms
Parasites
Parasitoids
Predators
Pathogens
Parasitoids vs Parasites:
What`s the difference ?
Parasitoids kill their hosts;
Parasites do not;
Parasitoids Parasites
Parasites
An organism that lives in a symbiotic
relationship with a phylogenetically
unrelated organism over a prolonged
period of time
A Parasite lives in or on its host
It obtains nourishment from its host
Parasites cannot live independently
Relationship lasts the lifetime of the
host
e.g. Epipyrop spp. (Lepidoptera) parasite of
sugarcane leafhopper, Trichogramma chilonis egg
parasite of ABW
Parasitoids vs Parasites:
A parasitoid is an organism that spends a
significant portion of its life history attached
to or within a single host organism
A parasitoid ultimately kills and often
consumes its host in the process
Parasitoids obtain nourishment from host,
but is not needed to survive
Relationship lasts the life cycle of its host
Parasitoids
Parasitoids
Parasitoids either lay eggs inside
the host or attach eggs to the
outside of host body
e.g. Insects from Coleoptera, Diptera,
Hymenoptera, Lepidoptera and
Neuroptera
Parasitoids with respect to host stage
Parasitise their host
Parasitoids with respect to effect on host
Idiobionts:
host development arrested or
terminated upon parasitization (e.g.
egg parasitoids)
Koinobionts:
host continues to develop following
parasitization (e.g. larval-pupal
parasitoids)
Parasitism may be:
Hyperparasitism (secondary parasitoids)
It is common for a parasitoid to itself serve
as the host for another parasitoid's offspring
Superparasitism
In which host is attacked by more than once
by a single species of parasitoid
Multiple parasitism
When host has been parasitized by more
than one species
Biological control...
Merits of parasitoids
They possess good survival
Require one host to complete life history
Sustain their population at low host levels
Mostly have a narrow host range
Biological control...
Dmerits of parasitoids
Host searching capacity strongly
reduced by weather conditions
Only female search host for egg laying
Even best female searcher lay few
eggs
Synchronization is difficult problem
with most parasitoids
Biological control...
Predators
Are free living organisms that feed
throughout their life on other
animals and kill their prey
Larger than prey and require more than
one to complete their development
Both immature and adult of many species
are predacious but some only on
immature stage
Predators
Biological control...
Pathogens
The pest population management
through disease causing microorganisms
Bacteria
Nematodes Viruses
Fungi
Biological control...
Bacteria
Primary prey:
Caterpillars, beetles and flies
Key characters:
larvae stop feeding, become limp and
shrunken
Key characters:
lethargy, swollen, reduce
feeding and fungus
covered
Biological control...
Nematodes
Steinernema spp.
Heterorhabditis spp.
Primary prey:
Soil dwelling insects of beetles and lepidoptera
Key characters:
flaccid and discolored
Biological control...
Techniques
in biological
control
Classical
biological
control
Augmentative
biological
control
Coservation
biological
control
Techniques in
biological control
Biological control...
Classical biological control
Involves the introduction of a pest's natural
enemies to a new location where they do not
occur naturally
Biological control...
Augmentative biological control
Mass rearing and production
The handicap natural enemies can be
removed in the field by releasing in desired
numbers and time periods
Inoculative releases
Inundative releases
Inoculative releases
Involves the releases of small numbers
and may be made infrequently as once a
year to re-establish a species of natural
enemies killed out periodically due to
unfavourable environmental conditions
Biological control...
Inundative releases
Involves the mass-releases of natural
enemies at frequent intervals to suppress
the pest population
Biological control...
Biological control...
Conservation biological control
Involves the avoidance of measures that
destroy natural enemies and providing
resources that enhancing their population
protection from pesticides
avoidance of harmful cultural practices
maintenance of biodiversity
supply of food and shelter resources
Reproductive control...
Control of insect pests by lowering their
reproductive potentials
Pest insects are used against members of
their own species to reduce population level;
may also called Autocidal or Sterile insect
technique (SIT)
Methods of sterilization
radiation
chemosterilization
other genetic tactics
Reproductive control...
In this method male insect population
exposed to high energy radiations like X-
rays and gamma rays cause mutation in
DNA, zygote formed but die early
e.g. mutation of drosophila melanogaster
pupae of screwworm produce sterile
adults
Radiation
Reproductive control...
In this method certain chemicals are
used to sterile insects, chemicals are
used to prevent gamete production
e.g. Alkylating agents, phosphorus
amides, Triazines, anti-metabolites
Chemosterilization