physical control of insect pests

1. PHYSICAL CONTROL
IN
IPM
Submitted To :- Submitted By :-
Dr O. P. Chaudhary Vaibhav
Prof. of Entomology

2. PHYSICAL CONTROL -
Methods which aim to reduce the
pest population by using devices
which affects them physically or
alter their physical environment.

3. USE OF :
 Temperature
 Moisture
 Light (radiations)
 Sound
PHYSICALCONTROL

4. Temperature :
Artificial heating or cooling of stored products,
grains etc. is a good method of pest control.
Low Temperature
High Temperature

5. Low temperature :
• Generally low temp. does not kill the insects, but slower down
the insect activities
• Nearly all insects become inactive at 60-40°F.
• Insects undergoes hibernation at 20 to 30°F.
• Practically no damage occur from insects at temperature
below 40°F.
• Low temp. is not as effective as high temp. in killing insects
but storage of food products and clothing, the temp. below or
near the freezing point will prevent insect damage.

7. High Temperature :
• It is very efficient method to control insects.
• No insect can survive longer when exposed to
temperature of 140-150°F.
• Most of the insects (stored grains pests) can
be killed within 2-3 hours exposure to temp.
from 125-130°F.

8. • In India and other tropical countries where
the SUN is strongly radiant, solar radiation can
be used for infected material like cotton seed,
grains, pulses, woolen goods etc.
• Super heating with burning charcoal can also
be used to raise temperature to destroy
stored pest in godowns.

11. Steam sterilization
• Steam sterilization of soil is very effective
against soil insects.
• Soil is covered with polythene sheet and
steam is throwed on the soil.

12. Vapour Heat Treatment (VHT)
• When exporting tropical fresh fruit, such as mango
and papaya, the fruit needs to go through strict plant
quarantine inspections to ensure that quarantine
pests such as eggs and larvae of Melon flies and
oriental fruit flies are not present in fruits.
• The Vapour Heat Treatment System achieves this
objective with the use of hot saturated water vapour,
and without the use of any chemicals.

13. • During the process, the temperature and
humidity are controlled so that the fruit is not
damaged and freshness is naturally preserved.
• The Vapour Heat Treatment System is a safe way
to treat fruit so that it passes the quarantine
inspection, enabling the fruit to be exported.
• Heated air is saturated with water (>RH 90%) for
specified period of 6-8 hrs. for raising pulp temp.
to 43-44.5°C in case of mango against fruit flies.

15. OXYGEN STRESS
• In air tight containers small volume of air is
enclosed, the available oxygen is quickly
utilized by insects and raise concentration of
carbon dioxide.
• High concentration of carbon dioxide leads to
death of stored products insects.

17. LIGHT
• Light affects insect behavior and development in a
variety of ways that can be divided into several
categories.
• One of the most typical responses to light is
PHOTOTAXIS
• Insects exhibit the following phototactic behaviors:
 Attraction
 Repulsion
• There are a wide range of responses to light beyond
phototaxis
 Light adaptation
 Circadian rhythms

19.  Attraction
• Positive phototaxis, moving toward a light source.
This response can be used to trap pests, but the effective wavelengths and
intensities vary among species.
 Repulsion
• negative phototaxis, moving away from light this can be used to prevent pests
from entering a cultivation area by presenting light at wavelengths and intensities
that repel them.
 Light adaptation
• when nocturnal insect species become light-adapted within several minutes of
exposure to and exhibit typical daytime behaviors such as cessation of movement
and settling down.
• Behaviors such as flight and mating are inhibited in nocturnal insects that are
exposed to bright light at night.
 Circadian rhythms
• are daily behavioral rhythms including flight, locomotion, feeding, courtship,
mating etc.
• Artificial lighting for a certain duration during the night can
• shift the timing of the diurnal/nocturnal behaviors of This response is called a
• ‘‘PHASE SHIFT’’

20. A - Attraction B - Repulsion
C - light adaptation D - Disturbance of circadian rhythm

21. Light traps
• Light traps are arranged for attracting the
insects, which are trapped by keeping water or
oil in a container or a killing bottle below the
light trap. Light traps are useful for monitoring
the population of important insect pests in an
area. Eg: Most of the moths and beetles.

23. RADIATION
• Male insects can be made sterile by exposing them to GAMMA
RADIATION or by using chemicals.
• When sterile males are released in normal population they
compete with normal males in copulation and to that extent
reductive capacity of the population are reduced.
• By sterilizing the pupae of screwworm, livestock pest (Cochliomyia
hominivorax) with radiations, sterile males were obtained.
• They were released @ 400/sq mile for 7 weeks. By this method
total eradication was achieved in South East parts of America and
in the Curacao islands in case of screwworm.

25. Flame thrower
• It is compressed air sprayer with kerosene oil
for producing flames.
• There is a lance, which is fitted with a burner.
When the burner is heated, the kerosene oil is
released and it turns into flames.
• Used for burning locust populations,
congregation of caterpillars, patches of weeds
etc.

28. Kaolinic Clay (China clay)
• is a clay mineral,
• Chemical composition Al2Si2O5(OH)4.
• It is a layered silicate mineral.
• Used after successive activation with acid and heat can be
mixed with stored grains.
• The clay minerals absorb the lipoid layer of the insect cuticle
by which the insects lose their body moisture and die due to
desiccation.

29. DRIE-DIE
Consists of highly porous, finely divided silica
gel.
It abrades the insect cuticle.
Loss of moisture from insect cuticle, causing
death of insect.
Mainly used against stored product pests.