CLIMATE CHANGE AND ITSCLIMATE CHANGE AND ITS
IMPLICATIONS ON CROPIMPLICATIONS ON CROP
PEST SCENARIOPEST SCENARIO
ByBy
Dr.L.N.MohapatraDr.L.N.Mohapatra
Associate Director of ResearchAssociate Director of Research
Regional Research and Technology Transfer StationRegional Research and Technology Transfer Station
BhawanipatnaBhawanipatna

Climate changeClimate change
Climate Change is one of the mostClimate Change is one of the most
important global environmental problems today.important global environmental problems today.
 It is a term used to describe a gradual increase in theIt is a term used to describe a gradual increase in the
average temperature of earth atmosphere and itsaverage temperature of earth atmosphere and its
oceans, a change that is believed to be changing theoceans, a change that is believed to be changing the
earth’s climate for ever.earth’s climate for ever.
 It is a long-term change in the statistical distribution ofIt is a long-term change in the statistical distribution of
weather pattern over periods of time that range fromweather pattern over periods of time that range from
decades to millions of years.decades to millions of years.
 It may be limited to a specific region, or may occurIt may be limited to a specific region, or may occur
across the whole world.across the whole world.

Reasons for climate changeReasons for climate change
• Planet Earth comprises of several layers. It starts withPlanet Earth comprises of several layers. It starts with
the three layers of the earth called as Crust , Mantle andthe three layers of the earth called as Crust , Mantle and
Core and then five layers of atmosphere namely,Core and then five layers of atmosphere namely,
Troposphere, Stratosphere, Mesosphere, ThermosphereTroposphere, Stratosphere, Mesosphere, Thermosphere
and Exosphere.and Exosphere.
• Now, the atmosphere provides air, water, warmth andNow, the atmosphere provides air, water, warmth and
protects the earth from the harmful rays (UV) of the sun.protects the earth from the harmful rays (UV) of the sun.
• The earth partially absorbs energy from the sun andThe earth partially absorbs energy from the sun and
simultaneously releases it in the form of infra red wavessimultaneously releases it in the form of infra red waves
(as heat we feel). This heat is not completely lost to(as heat we feel). This heat is not completely lost to
space, but is partially absorbed by some gases presentspace, but is partially absorbed by some gases present
in very small quantities in the atmosphere called asin very small quantities in the atmosphere called as
green house gases(GHGs) and they remit some of thisgreen house gases(GHGs) and they remit some of this
heat to the earth surface.heat to the earth surface.

Reasons for climateReasons for climate
change:change:
Man made activities :Man made activities :
• Burning of coal and oil for homes, factories andBurning of coal and oil for homes, factories and
transportation has increased the concentrationtransportation has increased the concentration
of Greenhouse Gases (carbon dioxide,of Greenhouse Gases (carbon dioxide,
methane,nitrous oxide,ozone andmethane,nitrous oxide,ozone and
chlorofluorocarbons) in the atmosphere, that ischlorofluorocarbons) in the atmosphere, that is
making the earth warmer day by day.making the earth warmer day by day.
This again causesThis again causes
• the mountain glaciers and frozen ice-capped seathe mountain glaciers and frozen ice-capped sea
and land masses to melt, leading to the increaseand land masses to melt, leading to the increase
in the amount of water in rivers, thus leading toin the amount of water in rivers, thus leading to
the rise of amount of water in oceans, whichthe rise of amount of water in oceans, which
exert pressure on continental and oceanic platesexert pressure on continental and oceanic plates
and leads to their movement inside, thus leadingand leads to their movement inside, thus leading
to earthquakes, tsunamis, volcanic activities,to earthquakes, tsunamis, volcanic activities,
etc.etc.

Reasons for climateReasons for climate
change:change:•
• Global atmospheric carbon oxide has increased appxly by 30%Global atmospheric carbon oxide has increased appxly by 30%
which is responsible for an increase of 0.6which is responsible for an increase of 0.6oo
C in mean annualC in mean annual
global surface temperatureglobal surface temperature
• There will be an increase in the atmospheric temperature toThere will be an increase in the atmospheric temperature to
the tune of about 1.8 to 4.0the tune of about 1.8 to 4.000
C by the end of 2100.C by the end of 2100.
• Burning fossil fuels alone accounts for 83% of India’s carbonBurning fossil fuels alone accounts for 83% of India’s carbon
dioxide emission.dioxide emission.
• India will become the 3India will become the 3rdrd
largest emitter of green house gaseslargest emitter of green house gases
by 2015.by 2015.
• If no climate policy interventions are made the concn. OfIf no climate policy interventions are made the concn. Of
atmos. carbon dioxide may increaseatmos. carbon dioxide may increase
upto- 405-460ppm by 2025upto- 405-460ppm by 2025
445-640ppm by 2050445-640ppm by 2050
540-970 ppm by 2100.540-970 ppm by 2100.

• Indian Agriculture (ruminants, riceIndian Agriculture (ruminants, rice
cultivation,manure management,cropcultivation,manure management,crop
residues etc.,) contributed 17.7 mresidues etc.,) contributed 17.7 m
tonnes of methane and 0.14 m tonnestonnes of methane and 0.14 m tonnes
of nitrous oxide with global warmingof nitrous oxide with global warming
potential (GWP) of 386.1 m tonnespotential (GWP) of 386.1 m tonnes
carbon dioxide equivalent .carbon dioxide equivalent .
• Ruminants are found largestRuminants are found largest
contributer of GWP (85%)followed bycontributer of GWP (85%)followed by
rice cultivation (23%) and soil(10%)rice cultivation (23%) and soil(10%)
Reasons for climate change:Reasons for climate change:

Possible impact of climate changePossible impact of climate change
• Unprecedented heat waves:Unprecedented heat waves:
• Cyclone- Intensity of Storm wouldCyclone- Intensity of Storm would
increase by at least 10%increase by at least 10%
• Flood- Precipitation may increase by 5-Flood- Precipitation may increase by 5-
10% due to intensification of the10% due to intensification of the
hydrological cyclehydrological cycle
• DraughtDraught
• Decreased snow coverDecreased snow cover
• Erratic monsoonErratic monsoon

Possible impact of climate changePossible impact of climate change
o Rising sea level causing displacement alongRising sea level causing displacement along
coast linecoast line
• Hot summer and warmer winterHot summer and warmer winter
• Increased water salinityIncreased water salinity
• More soil salination- decreased soil fertilityMore soil salination- decreased soil fertility
• Less cultivated land- Less crop productivityLess cultivated land- Less crop productivity
with low quality agricultural producewith low quality agricultural produce
• Increased incidence of insect pest and insectIncreased incidence of insect pest and insect
borne diseases in human being and effect onborne diseases in human being and effect on
rainfed agriculture , fisheries,livestock,healthrainfed agriculture , fisheries,livestock,health

Threats due to climate change inThreats due to climate change in
AgricultureAgriculture
• Increased temperatureIncreased temperature
drastically affected the ricedrastically affected the rice
production due to decrease inproduction due to decrease in
crop duration in Philippinescrop duration in Philippines
(10% reduction in yield in rice(10% reduction in yield in rice
per 1per 100
C rise in temperature.C rise in temperature.
• Reduction in yield due toReduction in yield due to
warm days and nights: leadswarm days and nights: leads
to less elongation of riceto less elongation of rice
grain and lower quality of ricegrain and lower quality of rice
,higher chaffyness,higher chaffyness

Threats due to climate change inThreats due to climate change in
AgricultureAgriculture
• An increase of 6An increase of 600
C in temperatureC in temperature
and precipitation deficit of 300mmand precipitation deficit of 300mm
reduced the maize yield by 36% inreduced the maize yield by 36% in
European UnionEuropean Union
• It will lead to a shift in cultivationIt will lead to a shift in cultivation
of crops in non traditional areaof crops in non traditional area
and change in cultural practicesand change in cultural practices
• Increase in temp. and carbonIncrease in temp. and carbon
dioxide cause availability of lessdioxide cause availability of less
irrigated water and more pest andirrigated water and more pest and
diseases of crop.diseases of crop.

Threats due to climate change in IndianThreats due to climate change in Indian
AgricultureAgriculture
• IARI study “ Vulnerability ofIARI study “ Vulnerability of
Indian Agriculture to climateIndian Agriculture to climate
change” reveals :change” reveals :
- an increase in temperature- an increase in temperature
by 1by 100
C may reduce the yield ofC may reduce the yield of
wheat ,soyabean, mustard,wheat ,soyabean, mustard,
ground nut and patato by 3-ground nut and patato by 3-
10%.10%.
• If the trend of climate changeIf the trend of climate change
continue in the same pace,continue in the same pace,
the losses will be 10-40% bythe losses will be 10-40% by
21002100..

Threats due to climate change in IndianThreats due to climate change in Indian
AgricultureAgriculture
• For one degree rise inFor one degree rise in
temperature in areas liketemperature in areas like
Uttar Pradesh, PunjabUttar Pradesh, Punjab
and Haryana couldand Haryana could
amount to a loss of aboutamount to a loss of about
6 million tonnes of wheat6 million tonnes of wheat
annuallyannually
• 0.5 degree rise in winter0.5 degree rise in winter
Temperature would reduceTemperature would reduce
wheat yield by 0.45t/ha.wheat yield by 0.45t/ha.

Effect of climate change on cropEffect of climate change on crop
pestspests
 Increased level of temperature andIncreased level of temperature and
carbon dioxide due to climate changecarbon dioxide due to climate change
have a profound influence on crop pestshave a profound influence on crop pests
(arthropods)(arthropods)
 Insects are poikilothermic(coldInsects are poikilothermic(cold
blooded organism), the temperature ofblooded organism), the temperature of
their body is proximately the same astheir body is proximately the same as
that of the environment.that of the environment.
 Temperature increase associated withTemperature increase associated with
climate change affect theirclimate change affect their
reproduction,development and survivalreproduction,development and survival

Effect of climate change on crop pestsEffect of climate change on crop pests
• UV radiation weakens the health of plants which leaves themUV radiation weakens the health of plants which leaves them
more vulnerable to pests and diseases which are earlier minor.more vulnerable to pests and diseases which are earlier minor.
• A rise in the carbon dioxide conc. increases the C:N ratio ofA rise in the carbon dioxide conc. increases the C:N ratio of
plants reducing the nutritional quality for the protein limitedplants reducing the nutritional quality for the protein limited
insects which increases their food intake (compensatoryinsects which increases their food intake (compensatory
feeding).feeding).
• Study says there is dilution of N by 10-30% and it cause 40%Study says there is dilution of N by 10-30% and it cause 40%
increase in food consumption by herbivores.increase in food consumption by herbivores.
• Increased carbon dioxide may cause a slight decrease in NIncreased carbon dioxide may cause a slight decrease in N
based defenses (alkaloid) and slight increase in carbon basedbased defenses (alkaloid) and slight increase in carbon based
defenses (tanins) in plants which breaks down of resistance ofdefenses (tanins) in plants which breaks down of resistance of
plants to insects .plants to insects .
Example: Sorghum midgeExample: Sorghum midge Stenodiploisis sorghicolaStenodiploisis sorghicola ..
Pest out breaks are more likely to occur with stressed plants as aPest out breaks are more likely to occur with stressed plants as a
result of weakening of plants defensive system, and thusresult of weakening of plants defensive system, and thus
increasing the level of susceptibility to insect pests.increasing the level of susceptibility to insect pests.

Impact of climate change on insectImpact of climate change on insect
pests populationpests population
• Extension of geographical rangeExtension of geographical range
It has been noted that insect population under increasing
temperature is under move towards higher latitudes and elevation.
• Increasing over winteringIncreasing over wintering
• Change in population growth rateChange in population growth rate
It has been estimated that with a 2o C temperature increase insects
might experience one to five additional life cycles per season
• Increased number of generationsIncreased number of generations
• Extension of development seasonExtension of development season

Impact of climate change on insectImpact of climate change on insect
pests populationpests population
• Change in crop pest synchronyChange in crop pest synchrony
• Change in inter specific interactionChange in inter specific interaction
• Increased risks of invasion by migrantIncreased risks of invasion by migrant
pestspests
• Introduction of alternative hosts and overIntroduction of alternative hosts and over
hostshosts

Examples of change in pest behaviour dueExamples of change in pest behaviour due
to climate changeto climate change

Unusually severe draughtUnusually severe draught
increases the damage byincreases the damage by
spotted stem borer in sorghumspotted stem borer in sorghum
 Boll worm incidence in cottonBoll worm incidence in cotton
may increase by 4.17% with anmay increase by 4.17% with an
increase of maximumincrease of maximum
temperature by 1temperature by 100
CC
 Aphid abundance increasesAphid abundance increases
with an increase of carbonwith an increase of carbon
dioxide and temperaturedioxide and temperature

Examples of change in pest behaviour dueExamples of change in pest behaviour due
to climate changeto climate change
• More occurrence of Cabbage maggot,More occurrence of Cabbage maggot,
onion maggot , European corn boreronion maggot , European corn borer
and Colorado potato beetleand Colorado potato beetle
• High temperature with humidity areHigh temperature with humidity are
subjected to severe cut worm damagesubjected to severe cut worm damage
• It will lead to earlier infestation byIt will lead to earlier infestation by
Helicoverpa zeaHelicoverpa zea inin North AmericaNorth America andand
H.armigeraH.armigera in North Indiain North India
• Shorter dry spell lead to more mites,Shorter dry spell lead to more mites,
mealy bug infestationmealy bug infestation

Examples of change in pest behaviour dueExamples of change in pest behaviour due
to climate changeto climate change
 Longer growing seasons with warmer climate will enable
insect pests such as grasshoppers to complete a greater
number of reproductive cycles during spring,summer and
autumn.
 Increase in rainfall will largely affect the species
particularly the beetle with poor dispersal capabilities,
which will limit their ability to expand their home.
Lower winter mortality of insects due to warmer winter
temperatures could be important in increasing insect
populations

Examples of change in pest behaviour dueExamples of change in pest behaviour due
to climate changeto climate change
 Changes in climatic variables have led to
increased frequency and intensity of
outbreaks of insect-pests. Outbreak of
sugarcane woolly aphid Ceratovacuna
lanigera Zehntner in sugarcane belt of
Karnataka and Maharashtra states during
2002-03 resulted in 30% yield losses

Examples of change in pest behaviour dueExamples of change in pest behaviour due
to climate changeto climate change
 Changes in climatic variables have led to
increased frequency and intensity of
outbreaks of fruitfly in cucurbits
particularly due to high temperature and
high RH
 Increasing infestation of rice crop by
swarming caterpillar,hispa,stem borer and
bacterial blight

Recent pest problem in different crop due toRecent pest problem in different crop due to
change in climate and cropping season inchange in climate and cropping season in
IndiaIndia
•
• Paddy: Pink stem borer, White stem borer, panicle mite,Paddy: Pink stem borer, White stem borer, panicle mite,
blue beetle in Kerala, white grub inblue beetle in Kerala, white grub in
Uttaranchal ,Uttaranchal ,
root aphid in upland riceroot aphid in upland rice
• Maize: Corn borerMaize: Corn borer Helicoverpa armigeraHelicoverpa armigera in Andhrain Andhra
PradeshPradesh
• Cotton: Tobacco caterpillarCotton: Tobacco caterpillar Spodoptera armigeraSpodoptera armigera
• Sugar cane: Wooly aphid, Yellow mite, cane flySugar cane: Wooly aphid, Yellow mite, cane fly

Recent pest problem in different crop due toRecent pest problem in different crop due to
change in climate and cropping season inchange in climate and cropping season in
IndiaIndia
• Red gram: Spotted pod borer, LeafRed gram: Spotted pod borer, Leaf
webberwebber
• Chilli: Blossom midgeChilli: Blossom midge
• Ground nut: Leaf minerGround nut: Leaf miner
• Castor: Tobacco caterpillarCastor: Tobacco caterpillar SpodopteraSpodoptera
armigeraarmigera

Impact of Climate change on naturalImpact of Climate change on natural
enemiesenemies
• Climate change can have diverse effects onClimate change can have diverse effects on
natural enemies of pests species, likenatural enemies of pests species, like
enhanced mortality with increasingenhanced mortality with increasing
temperatures, their decreased effectiveness intemperatures, their decreased effectiveness in
controlling pests when pest distribution shiftcontrolling pests when pest distribution shift
into regions outside the distribution of theirinto regions outside the distribution of their
natural enemies, affected by climate.natural enemies, affected by climate.
• Changes in temperature will also alter theChanges in temperature will also alter the
timing of diurnal activity patterns of differenttiming of diurnal activity patterns of different
groups of insects and change in interspecificgroups of insects and change in interspecific
interactions could also alter the effectivenessinteractions could also alter the effectiveness
of natural enemies for pest management.of natural enemies for pest management.
• Temperature not only affects the rate of insectTemperature not only affects the rate of insect
development, but also has profound effect ondevelopment, but also has profound effect on
fecundity and sex ratio of parasitoids.fecundity and sex ratio of parasitoids.

Impact of Climate change on naturalImpact of Climate change on natural
enemiesenemies
• Natural enemies of the insect-pests
are more sensitive to the climatic
extremes like heat, cold, wind and
rains.
• Precipitation changes can also
affect predators, parasites and
pathogens of insect-pests resulting
in a complex dynamics.
• With changing climate, incidence of
entomopathogenic fungi might be
favoured by prolonged humidity
conditions and obstinately be
reduced by drier conditions

Impact of Climate change onImpact of Climate change on
pollinators:pollinators:
• Climate change affect the phonology,Climate change affect the phonology,
local abundance and large scalelocal abundance and large scale
distribution on plants and pollination.distribution on plants and pollination.
Insect pollinated plants react moreInsect pollinated plants react more
strongly to increased warming thanstrongly to increased warming than
wind pollinated plants.wind pollinated plants.
• Quantum of pollination decrease asQuantum of pollination decrease as
there is disruption of naturalthere is disruption of natural
synchronization between the flowersynchronization between the flower
opening and visit of the pollinators likeopening and visit of the pollinators like
honey bees, wasps and butterflies.honey bees, wasps and butterflies.
• Increasing spring temperatures mayIncreasing spring temperatures may
decrease flower abundance and affectdecrease flower abundance and affect
the relative abundance of pollinatorthe relative abundance of pollinator
species. . Recent study says that forspecies. . Recent study says that for
every one degree celsius rise inevery one degree celsius rise in
temperature there will be 14% loss intemperature there will be 14% loss in
butterfly population.butterfly population.

Effect of Climate change on cropEffect of Climate change on crop
protection technologiesprotection technologies
• Increase in temperature and precipitation lead to rapidIncrease in temperature and precipitation lead to rapid
dissipation of insecticide residues for which moredissipation of insecticide residues for which more
frequent application is needed.frequent application is needed.
• Increase in temperature, U.V. radiation and decrease inIncrease in temperature, U.V. radiation and decrease in
R.H. may render natural plant products, entomoR.H. may render natural plant products, entomo
pathogenic virus, fungus, bacteria, nematode to be lesspathogenic virus, fungus, bacteria, nematode to be less
effective.effective.
• Due to high temperature the synthetic pyrethroids andDue to high temperature the synthetic pyrethroids and
biopesticide show less efficacy due to degradation.biopesticide show less efficacy due to degradation.
• Break down of natural resistance in crop plants to insectBreak down of natural resistance in crop plants to insect
pests.pests.

Effect of Climate change on cropEffect of Climate change on crop
protection technologiesprotection technologies
• Activity and effectiveness of natural enemiesActivity and effectiveness of natural enemies
( parasites and predators ) is also affected.( parasites and predators ) is also affected.
• Effect of Climate change on transgenic cropEffect of Climate change on transgenic crop
Soil moisture, soil fertility and temperatureSoil moisture, soil fertility and temperature
have strong influence of expression ofhave strong influence of expression of
Bacillus thuringiensisBacillus thuringiensis toxin diploid intoxin diploid in
transgenic plants.transgenic plants.
Ex- Cotton bollworm (Ex- Cotton bollworm (Helicoverpa virescensHelicoverpa virescens))
destroys the Bt transgenic cotton due todestroys the Bt transgenic cotton due to
high temperature in Texas. Possible reasonhigh temperature in Texas. Possible reason
is inadequate production of toxin protein andis inadequate production of toxin protein and
effect of environment on transgenic crop.effect of environment on transgenic crop.

Climate change and pestClimate change and pest
management: Challenges Aheadmanagement: Challenges Ahead
• Emission of greenhouse gases can beEmission of greenhouse gases can be
minimized through adoption of conservationminimized through adoption of conservation
agriculture like direct seeded rice, aerobic rice,agriculture like direct seeded rice, aerobic rice,
SRI(System of Rice Intensification), cropSRI(System of Rice Intensification), crop
diversification, organic farming, bio-organicdiversification, organic farming, bio-organic
fertilisers and biological pest control, etc.fertilisers and biological pest control, etc.
• Development of crop growth simulation modelsDevelopment of crop growth simulation models
will be of greater relevance in new emergingwill be of greater relevance in new emerging
research areas such as climate change impactsresearch areas such as climate change impacts
on pests and crop yield.on pests and crop yield.

Climate change and pestClimate change and pest
management: Challenges Aheadmanagement: Challenges Ahead
For effective pest management there is need to :For effective pest management there is need to :
• Predict and map trends of potential changes inPredict and map trends of potential changes in
geographical distribution and study how climaticgeographical distribution and study how climatic
changes will affect development, incidence andchanges will affect development, incidence and
population dynamics of insect pests.population dynamics of insect pests.
• Understand the influence of climate change on speciesUnderstand the influence of climate change on species
diversity and cropping patterns and their influence on thediversity and cropping patterns and their influence on the
abundance of insect pests and their natural enemies.abundance of insect pests and their natural enemies.
• Understand the changes in expression of resistance toUnderstand the changes in expression of resistance to
insect pests and identify stable sources of resistanceinsect pests and identify stable sources of resistance
and pyramid the resistance genes in commercialand pyramid the resistance genes in commercial
cultivars.cultivars.

Climate change and pestClimate change and pest
management: Challenges Aheadmanagement: Challenges Ahead
For effective pest management there is need to :For effective pest management there is need to :
• Exhaustive studies on the effect of climateExhaustive studies on the effect of climate
change on the efficacy of transgenic crops inchange on the efficacy of transgenic crops in
pest management.pest management.
• Assess the efficacy of various pest managementAssess the efficacy of various pest management
tools under variable environmental conditionstools under variable environmental conditions
and develop viable pest management strategiesand develop viable pest management strategies
to mitigate the effects of climate change on foodto mitigate the effects of climate change on food
security.security.