This document discusses the impacts of climate change on insect pests. It begins with definitions of climate change and its causes, including both natural factors and human activities that increase greenhouse gases. Sections then examine how rising temperatures, CO2 levels, and changes in precipitation patterns can indirectly and directly affect insect populations, ranges, development, and interactions with plants. Specifically, climate change may lead to faster insect growth, expanded ranges, altered life cycles, and increased outbreaks. The conclusion states that predicting climate change impacts is complex, as some factors may help or harm different insects, requiring further research on species' sensitivities.

1. WEL-COME

3. CONTENTS :-
1.Introduction
2.Causes of climate change
3.Impact of climate change on
insect pests
3.Global warming and climate
changes on insects
4.Effect of fluctuating temperature
on insects
5. Effect of elevated CO2 on insects
6.Precipitation and population
dynamics
7.Drought and insect population
dynamics
8. Conclusion

4. CLIMATE CHANGE
“Climate change refers to the
phenomenon that is causing the
earth to become warmer which
means that our climate and our
weather systems are changing”
(SEI Report, 2000)

5. Causes of Climate Change
• Planet Earth comprises of several layers. It starts
with the three layers of the earth called as Crust ,
Mantle and Core and then five layers of atmosphere
namely, Troposphere, Stratosphere, Mesosphere,
Thermosphere and Exosphere.
• Now, the atmosphere provides air, water, warmth
and protects the earth from the harmful rays (UV) of
the sun.

6. Causes of Climate Change
• The earth partially absorbs energy from the sun
and simultaneously releases it in the form of infra
red waves (as heat we feel).
• This heat is not completely lost to space, but is
partially absorbed by some gases present in very
small quantities in the atmosphere called as green
house gases(GHGs) and they remit some of this
heat to the earth surface.

7. Causes of Climate Change
• Man made activities :
• Burning of coal
• Industrilization
• Deforestation
• Natural environments to urban
environments
• Use of refrigerator and AC’s,
(CFC)
• Transportation has increased the
concentration of Greenhouse
Gases

8. Causes of Climate Change
• Natural causes
The mountain glaciers, frozen ice-capped sea and
land masses to melt, leading to the increase in the
amount of water in rivers, thus leading to the rise
of amount of water in oceans, which exert
pressure on continental and oceanic plates and
leads to their movement inside, thus leading to
earthquakes, tsunamis, volcanic activities, etc.

9. Causes of Climate Change
• Global atmospheric carbon oxide has increased appxly by
30% which is responsible for an increase of 0.6℃ in mean
annual global surface temperature
• There will be an increase in the atmospheric temperature to
the tune of about 1.8 to 4.0℃ by the end of 2100.
• Burning fossil fuels alone accounts for 83% of India’s carbon
dioxide emission.
• Now, India is the 3rd largest emitter of green house gases.
• If no climate policy interventions are made the concn. Of
atmos. carbon dioxide may increase upto-
405-460ppm by 2025
445-640ppm by 2050
540-970 ppm by 2100

10. Causes of Climate Change
• Indian Agriculture (ruminants, rice
cultivation,manure management, crop residues
etc.,) contributed 17.7 million tonnes of methane
and 0.14 million tonnes of nitrous oxide with
global warming potential (GWP) of 386.1 million
tonnes carbon dioxide equivalent .

11. Causes of Climate Change

12. Climate change caused by human activity
Anthropogenic factors

15. IEA/OECD, 2013
Review of World Energy report, 2014

16. Contribution of different sectors to
Greenhouse Gas Emission in India
Energy
Supply
67%
Agriculture 22%
Industrial
Processes
8%
Waste 2%
Land Use
Changes
1%
Energy supply
Agriculture
Industrial processes
Waste

17. Expected effects of climate change for India:
examples(INCCA 2010)
• Agriculture
– Up to 50% reduction in maize yields
– 4-35% reduction in rice yields
– Negative impacts on livestock in all regions
• Fresh water supply
– High variability predicted in water yields (from 50% increase to
40-50% fall)
– 10-30% increased risk of floods; increased risks of droughts
• Forests and natural ecosystems
– Shifting forest borders; negative impact on livelihoods and
biodiversity
• Human health
– Higher morbidity and mortality from heat stress and
vector/water-borne diseases
– Expanded transmission window for malaria

18. How might the climate change?
1. Temperature increases - An increase in global
mean annual temperatures of 1°C by 2025 and 3°C
by the end of the next century.
2. Sea Level Rises - Global mean sea level is estimated
– risen 10-25cm over the last 100 years.
In the next 100 years the average sea level is
projected to be about 50cm
3. Increased Variability of Weather Events
4. Carbon dioxide level increases – concentration of
Carbon dioxide have increased from 280 ppm to
400 ppm over the last 150 years

19. Projected Impacts Of Climate Change On
Agriculture
1. Increased crop and pasture yields in colder
environments and decreased yields in
warmer and seasonally dry environments
2. Increased insect outbreaks
3. Reduction in yields in warmer regions due to
heat stress
4. Increased heavy precipitation events, causing
damage to crops, soil erosion and difficulty in
land cultivation

20. Projected Impacts Of Climate Change On
Agriculture
5. Increased area affected by drought, leading
to land degradation, lower yields and more
livestock deaths
6. Storm intensity increased, leading to
damaged crops and uprooting of trees
7. Increased sea level, causing salinization of
irrigation water and freshwater systems
Mathew et al., 2011

22. Impact Of Climate Change On Insect Pests
Indirect effect Direct effect
Due to change in:
• Host physiology
• Host nutritional status
• Activities of man
(change in varieties,
cropping systems ,
inter cropping etc.)
Results of increased
- Temperature
- Carbon dioxide
- Precipitation

23. Possible Impacts on Insects under Climate
change…..
• Extension of geographical range of insect pests
• Increased over-wintering and rapid population growth
• Changes in insect – host plant interactions
• Increased risk of invasion by migrant pests
• extinction of species
• Changes in synchrony between insect pests and their
crop host
• Introduction of alternative hosts as green bridges
• Reduced effectiveness of crop protection technologies
Sharma, 2010

24. Climate change affect insect
populations by
• Extending the growing season
• Altering timing of emergence
• Rapid growth and development rates
• Shortening generation times
• Prolonged overwintering
• Shorten predation window
• Altering geographic distribution

25. Range Expansion Of Insect Pests Due
To Climate Change
(Fand et al., 2012)

26. Impact Of Climate Change On Insect Survival
And Population Build Up
(Fand et al., 2012)

27. Impact Of Climate Change On Future Geographic
Range And Distribution Of Insect Pests
Insect pests Order/Family Host plants Impact on
Insects/Behavioural
response
References
Corn
Helicoverpa zea,
H. armigera
Lepidoptera
/Noctuidae
Maize • Altitudes wise range
expansion and
increased
overwintering
Survival
Deffenbaugh
et al.,
2008
Cottony cushion
scale,
Icerya purchasi
Lepidoptera
/Monophleb
idae
Polyphagous Populations appear to
be spreading
northwards
Cannon, 1998
Cotton bollworm
/Pulse pod borer
Helicoverpa
armigera
Lepidoptera
/Noctuidae
Cotton, Pulses,
vegetables
• Expansion of
geographic range in
Northern India
•Adult flights/
migratory behaviour
Sharma et al.,
2005;
2010

28. Insect Outbreaks In Relation To Climate
Change

29. EFFECT OF FLUCTUATING
TEMPERATURE ON INSECTS

30. Effect of enhanced atmospheric
temperature on crop pest dynamics
INCREASING ATMOSPHERIC TEMPERATURE
LEADS TO……
REFERENCES
Increasing...
Northward migration Parmesan, 2006
Migration up elevation gradients Epstein et al., 1998
Insect developmental rates and oviposition Regniere, 1983
Potential for insect outbreaks Bale et al., 2002
Invasive species introductions Dukes and Mooney, 1999
Insect extinctions Thomas et al., 2004
Decreasing…
Effectiveness of insect biocontrol by fungi Stacy and Fellowes, 2002
Reliability of economic threshold levels Trumble, John and Butler, Casey, 2009
Insect diversity in ecosystems Erasmus et al., 2002
Parasitism Hance et al., 2007; Fleming and Volney,
1995

31. Temperature Influence On Insect
• Temperature influences insect
- Behaviour
- Distribution
- Development
- Survival
- Reproduction
• Every species has a particular threshold of
temperature
• Above which – development occurs
• Below which - development ceases

32. Effect of Fluctuating Temperature on
Insect Biology
Pest Zoological Name Temp. Biology Temp. Biology References
American
Cockroach
Periplaneta
americana
> 21°C Year round
activity
27°C Egg to
adult,
24weeks
Benson and
Zungoli,
1997
Bed Bugs Cimex lectularius 18°C 128 days,
egg
to adult
30°C 24 days,
egg to
adult
Usinger,196
6
Cat flea Ctenocephalides
felis
13°C Egg hatch,
6
days
35°C Egg hatch,
36
hours
Silverman
et al.,
1981

33. Pest Zoological
Name
Temp. Biology Temp. Biology References
House fly Musca
domestica
>20°C Larval stage,
6-
8 weeks
21-32°C Larval stage,
3-7 days
Ehmann,
1997
Indian meal
moth
Plodia
interpunctella
20°C Life cycle, 60
days
25°C Life cycle, 30
days
Cox and
Bell,
1991
Yellow fever
mosquito
Aedes aegypti 25-29°C Optimum
larval
development
26°C Optimum
adult
developmen
t
Fay, 1964

34. EFFECT OF ELEVATED CO2 ON
INSECTS

35. Predicted Effects Of Elevated CO2 Conditions
On Plants And Insect Herbivores
(Cornellisen, 2011)

36. Effect Of Increasing Atmospheric CO2 On Plant-
Insect Interaction
Increasing Atmospheric CO2 leads to References
Increasing……………
Food consumption by caterpillars Osbrink et al., 1987
Reproduction of aphids Bezemer et al., 1999
Predation by lady beetle Chen et al., 2005
Carbon based plant defenses Coviella and Trumble, 1999
Effect of foliar application and Bacillus thuringiensis Coviella and Trumble, 2000
Decreasing………….
Insect development rates Osbrink et al., 1987
Response to alarm pheromones by aphids Awmarck et al., 2000
Parasitism Roth and Lndroth, 1995
Effect of transgenic B. thuringiensis Coviella et al., 2000
Nitrogen-based plant defense Coviella and Trumble, 1999

37. Common
name
Scientific name Effect Reference
Elevated CO2 and insect pests
Colorado beetle Leptinotarsa
decemlineata
23.8% larger dry mass Vaccari et al .,2000
Aphids Myzus persicae Not be negatively affected by
increased CO2
Hughes and Bazzaz,
2001
Bollworm H.armigera Significant differences in growth
& development
Wu G et al.,2006
Elevated CO2 on transgenic plants and insect pests
Tobacco bud
worm
Spodoptera exigua Limited N produced less toxin Coviella et al., 2000
Spodoptera exigua N based toxin was affected Coviella et al., 2002
Boll worm H.armigera Decrease in Bt toxin level Ge Feng et al., 2005

38. Pest complex under elevated CO2
Insects Elevated CO2
(570 ppm) References
Japanese beetle
Potato leaf hopper
Western corn root worm
Mexican bean beetle
57% more damage (Trumble and Butler, 2009)
Thrips 90% more feeding (Heagle, 2003)
Cereal aphid Higher population (Newman , 2004)

39. INDIRECT EFFECTS OF CO2 ON INSECTS
• Increases in CO2 can
cause changes, chemical
composition of plant
tissues.
• Phytophagous insects are
indirectly affected by this
change in their host
plants.
• Decreases - protein
content
• Increases- C/N ratio in the
leaves reduction in food
quality results in poor
growth.
(Coviella et al., 1999)

40. Impact of Precipitation on Insects
• High humidity may favour some insects e.g. aphids
• Thrips and white flies are sensitive to precipitation
and are killed or removed from crops by heavy rains
• Out breaks of Amsacta moorei are directly related to
heavy and frequent rains
(Saini and Ram, 2000)
• Reductions in summer rainfall can alter the diversity
and abundance of plant communities and their
associated invertebrates
(Morecroft et al ., 2004 )

41. Drought and insect population dynamics
• Drought may result in
various physiological changes
in plants that can increase
their attractiveness and
susceptibility to herbivorous
insects
• Droughts increase pathogen
and insect survival and
growth due to change in
nutrient level particularly
nitrogen , decrease in plant
defense system and creates
more favorable conditions
for pest attack

42. CONCLUSION
Global warming and climate change virtually
affects all the possible changes in insects in one
way or other. Predicting the impact of climate
change on insects is a very complex exercise
and a one that involves a great deal of
modeling. The precise impacts of climate
change on insects is somewhat uncertain
because some climate changes may favors
insects while others may inhibit a few insects.
More work is required to identify the effects of
weather and climate on important agricultural
pests, and determine the climatic variables to
which different species are most sensitive.

43. Thanks……