Climate change embraces a range of natural and anthropogenic environmental changes. According to Inter governmental Panel on Climate Change • “Change in climate over time, either due to natural variability or as a result of human activity”. • “A change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels.”

1. Seminar incharge
Dr. Hem Singh
Dr. D.V. Singh
Speaker
Sushant Kumar
Ph.D. Entomology
Id. No. - PG / A 3935/19

2. Global Warming Climate Change
Broader term that refers to
long term changes in climate,
including average temperature
and precipitation
Increase of the earth’s average
surface temperature due to a
build-up of greenhouse gases
in the atmosphere
Introduction
➢ Long-term change in the statistical distribution of weather
pattern over periods of time that range from decades to millions
of years.
➢ Can be limited to a specific region, or may occur across the
whole world

3. Change of climate that is attributed directly or indirectly by human activity
Alters the composition of the global atmosphere and climate variability observed
over comparable time periods.
Past some decades, the gaseous composition of earth’s atmosphere is
undergoing a significant change, largely through increased emissions from -
Energy sector
Industry sector
Agriculture sectors
Widespread deforestation.
Fast changes in land use.
Land management
practices

4. Insects are the numerous form of animal on the planet with one
million insect species described.
Close to 80% of all animal species, human have described are
insects.
Insects are the most important from the point of
1.ecosystem functioning(energy recycling)
2. economically important
crop pests
vectors
pollinators
productive

5. Natural Causes
Continental drift
Volcanoes
The earth's tilt
Ocean currents
Anthropogenic Causes
 large-scale use of fossil fuels
for industrial activities
 Greenhouse gases and their
sources
 our daily lives contribute
our bit to this change in the
climate

6. Possible impact of climate change
Unprecedented heat waves
Cyclone- Intensity of Storm would
increase by at least 10%
Flood- Precipitation may increase
Draught
Decreased snow cover
Erratic monsoon

8. Increased Temperature
Habitat Damage and
Species Affected
Changes in Water Supply

9. Global climatic changes can affect agriculture through their direct and
indirect effects on the crops, soils, livestock and pests.
The increase in temperature can
 Reduce crop duration.
 Increase crop respiration rates.
 Alter photosynthate partitioning to economic products.
 Affect the survival and distribution of pest populations.
 Hasten nutrient mineralization in soils.
 Decrease fertilizer-use efficiencies.
 Increase evapo-transpiration rate.
 Insect-pests will become more abundant through a number of inter- related
processes, including range extensions and phenological changes, as well as
increased rates of population development, growth, migration and over-wintering.

11. An annual loss of about Rs 8,63,884 million due to insect pests in India.
(Dhaliwal et. al., 2010).
Impact of climate change on agriculture has been the most important
research topic and intensively debated in recent times.
 Shift in species distribution
 Change in Phenology
 Increase in population growth rate
 Increase number of generations
 Change in migratory behavior
 Emergence of new pests or
biotypes
 Change in bionomics of insect
Change in feeding habits
 Change in community structure

12. Disease
Triangle
Environment
Climate change
CO2
Precipitation
Temperature
Pathogen change
Genetic shift
Movement
Host change
Variety
Cultural practice
Chemical practice

14. CO2 Effect on Insect-Pests
Increasing Food consumption by caterpillars
Reproduction of aphids
Effect of foliar application of Bacillus thuringiensis
Consumption and N utilization efficiency in pine saw fly and Gypsy
moth
Larval growth in pine saw fly
Pupal weight in blue butterfly
Feeding and growth rate in tobacco caterpillar
Fecundity of aphids on cotton
Decreasing Insect development rates
Development and pupal weight in Chrysanthemum leaf miner
Response to alarm pheromones by aphids
Lipid concentration in small heath Parasitism
Effect of transgenics to Bacillus thuringiensis
Nitrogen based plant defence
Control of grain aphids with sticky traps

15.  There was an outbreak of S. litura on soybean in Kota region of Rajasthan
and a loss of Rs 300 crore was estimated.
 The pest also struck in epidemic form on soybean in Vidarbha region
of Maharashtra in August 2008 and caused severe losses in yields to the tune
of 1392 crores.
 As Bt cotton (BG-1) does not provide protection against the pest, it inflicts
heavy losses in cotton. The intensity of S.litura is likely to further increase
under the potential climate change, as it has been found to consume more
than 30 per cent cotton leaves at elevated CO2 levels (Kranthi et al., 2009).
Tobacco caterpillar (Spodoptera litura)

16. Under CO2 soybean lose their ability to
produce jasmonic acid, and that whole
defence pathway is shut down.
Attract many more adult Japanese
beetles than plants grown under
ambient level.
The beetles lived longer, and produced
more offspring, than those living
outside
Evan Delucia, 2008

17. Pea plants had reduced nitrogen content when
grown under higher levels of CO2 and this in turn
influenced the size of the cotton bollworm larvae
Predatory bugs were more effective under higher
CO2 levels because they appeared to be better at
subduing the smaller bollworm larvae.
Result indicating that elevated CO2 may benefit generalist predators through
increased prey vulnerability.
Within the parasititoids the specialists which are host specific are likely to be more
adversely affected than generalist.
Coll and Hughes,2008

18. Common
name
Host plant
CO2 Conc.
(ppm)
Effect on Host
plant
Impact on
Insect
References
Gypsy moth Sessile Oak 530
42% increase in
Starch. Decrease
N , increase in
condensed tannins
RGR reduced
by 30%
Schafeltner et
al., 2004
Gypsy moth Red maple Amb.+300
Decreased N and
Increased C:N
ratio
Reduced larval
growth
Williams et
al., 2000
Gypsy moth White oak Amb.+300
Decreased N and
higher TNC
Growth
reduction in
early instar
Williams et
al., 1998
Gypsy moth Gray birch 700
Decrease N ,
increase in
condensed tannins
38% decrease
in pupal mass
and decline in
RGR
Traw et al.,
1996
Beet
armyworm
Upland
cotton
900 Decreased N,
Increased C:N
25% increased
in consumption
longer dev.
time
Coviella and
Trumble,200
0

19. Tobacco
Caterpiller
Mung bean 600
Decreased N,
increase in
Starch and TSS
Increased
feeding and
reduced
growth rate
Srivastava et
al., 2002
Western
flower thrips
Common
milk weed
700
Decreased N and
C:N, higher above
ground biomass
Density
decreased,
and leaf area
damaged
increased by
33%
Hughes and
Bezzaz, 1997
CottonAphid Bt cotton 800
Increase C:N ,
plant height ,
Biomass and leaf
area
Increased
fecundity
Chen et al.,
2005
GrainAphid Spring wheat 750
Decreased N,
Increased starch,
sucrose, glucose,
TNC , Free AA
and soluble protein
Population
increased
Chen et al.,
2004

20. Ambient CO2 Elevated CO2
Parameter G1 G2 G3 G1 G2 G3
Larval
period(days)
10.7 aB 11.4 aB 15.5 aA 13.0 aB 14.6 aB 16.1 aA
Pupal period
(days)
9.50 aA 9.46 aA 10 aA 9.92 aA 9.80 aA 9.93 aA
Adult period
(days)
7.80 aB 7.33 aB 8.92 aA 7.85 aA 7.31 aA 8.23 aA
Mortality 0.40 aA 0.34 bA 0.32 aA 0.44 aA 0.48 aA 0.41 aA
Fecundity 661aA 586aA 565aA 702aA 386aA 589aA
Fed onArtificial diet
Yin et al. (2010)

21. Fed onArtificial Fed on Maize grains
Result: Population consumption by cotton bollworm on maize will be
significantly increased under elevated CO2 in the future
Yin et al. (2010)
0
0.2
0.4
0.6
0.8
1
G1 G2
Individual
consumption
on
Maize
grains
(g)
Generation
0
0.2
0.4
0.6
0.8
1
1.2
G1 G3
Individual
consumption
on
artificial
diet
(g)
G2
Generation
Ambient CO2 Elevated CO2

22. Effect of Precipitation

23. Distribution and frequency of rainfall may also affect the incidence of
pests directly as well as through changes in humidity levels.
Armyworm, Mythimna separata,
reaches outbreak proportions after
heavy rains and floods.
Lever (1969) had analysed the
outbreaks of
relationship
armyworm
Spodoptera
between
and to
mauritia
a lesser extent
(Boisd.) and
rainfall from 1938 to 1965 and observed
that all but three outbreaks occurred
when rainfall exceeded the average 89
cm.

24. Aphid population on wheat and other
crops was adversely affected by rainfall
and sprinkler irrigation (Daebeler and
Hinz, 1977; Chander, 1998).
In Sub-Saharan Africa, changes in
rainfall patterns are driving migratory
desert locust
patterns of the
(Schistocerca gregaria).
Helicoverpa armigera
severity showed higher
damage
November
rainfall favoured higher infestation.

25. •Unpredictable rains might disrupt the parasitoids ability to track their
caterpillar hosts.
•Too much water will be devastating for some pests especially soil dwelling
insects.
•Rain drops can physically dislodge insects from their host plant and
behavior patterns can be disrupted in small insects such as thrip.
•Some pest species are suppressed by periods of rainfall , by outbreak of
fungal diseases as observed among aphids on lettuce and Brassica crops.
•It is anticipated that the cut worm outbreaks may become more frequent
due to effect of summer rains .
•Pesticide application and efficiency is also affected.

27. Years (Jan-Dec) °C °F
2016 0.99 1.78
2019 0.95 1.71
2015 0.93 1.67
2017 0.91 1.64
2018 0.83 1.49
2014 0.74 1.33
2010 0.72 1.30
2005 0.67 1.21
2013 0.67 1.21
2001 0.52 0.94
National Climatic Data Centre, NOAA, December 2020

28. Temperature Effect on Insect-Pests
Increasing Northward migration
Migration up elevation gradient
Insect development rate and oviposition
Potential for insect outbreaks
Invasive species introductions
Insect extinctions
Decreasing Effectiveness of insect bio-control by fungi
Reliability of economic threshold levels
Insect diversity in ecosystems
Parasitism
(Source: Das et al., 2011; Parmesan, 2006; Bale et al., 2002; Thomas et al., 2004

30. 1. Extension of geographical range
2. Increased over wintering
3. Changes in population growth rate
4. Increased number of generations
5. Extension of development season
6. Changes in crop pest synchrony
7. Changes in inter specific interaction
8. Introduction of alternative hosts
Bale et al. (2002)

31.  Insects are cold-blooded, sensitive to temperature
 Higher temperature increase rates of development and with less time between
generations
 20C temperature increase insects experience one to five additional life cycles
per season
 Eg. Cabbage maggot, Onion maggot, European corn borer, Colorado
potato beetle
 Warmer winters -
 Reduce winterkill and consequently induce increased insect populations
 It cause delay in onset and early summer may lead to faster termination of
diapauses in insects
 Reproductive rate-
 Rising temperatures will lengthen the breeding season and increase the
reproductive rate
 raise the total number of insects attacking a crop and subsequently
increase crop losses

32.  10C rise would enable species to spread 200km Northwards or 140
m upwards in altitude.
 Earilar infestation by Helicoverpa zea in N. America (EPA,1989) and
Helicoverpa armigera (Hub.) in North India and exploitation to new
areas.
 20C temperature increase insects might experience one to five additional
life cycles per season.
 Population of rice stem borer & green leaf
hopper increases with increasing winter temp. not by
summer temp.
 Mountain pine beetle, has extended its range northward by 300 km with
temp. increase of 1.9oC (Logan and Powell, 2001).

33. Of 46 species of butterflies that approached their northern climatic range in
Britain three-quarters of them declined , dual factors of habitat modification
and climate change are likely to cause specialists to decline, leaving biological
communities with reduced number of species and dominated by mobile and
widespread habitat generalists.
Warren et al. (2001)
Some species may be able to complete more generations in a year. This may be
most noticeable in insects with short lifecycle such as aphids and diamond
back moth.
•In aphids a increase of 2oC temperature causes one to five additional life
cycles per season.
•Warm temperature have halved the time required to reproduce in Spruce
beetle, Dentroctonus rufipennis.

34. temperatures during the period 2025-50
Trnka et al. (2007)
Larval development and adult fecundity of
winter moth was adversely affected by increased
temperature on Q. robur
Dury et al. (1998)
kms with an
An increase in 1-30C in temp. will cause northwards shifts in potential
distribution of Eoropean cornborer Ostrinia nubalis (Hub.) upto1,220
additional generation in all known areas currently occuring. Portal et al.1991.

35. At higher temperatures, aphids have
been shown to be less responsive to
alarm pheromone resulting in
potential for greater predation.
Awmack et al.2007
Temp. influcened the fecundity and sex ratio of Compoletis chloridae
larval parasitoid of Helicoverpa armigera.
(Dhillon and Sharma,2009)
Oriental armyworm, Mythimna separata populations increases during
extended period of drought ,which is detrimental to natural enemies.
(Sharma et al.2002).

36. OPC has increased steadily
over the years, moving in
north-eastern direction
Observed 1°C
temperature
corresponding
increase in
and the
increase in
growing season length in the
recent decades have
stimulated the spreading
Alexander et al.,2008
1991/1993 2006/2007
OPC distribution maps

37. Temperature response of the parasitoids determines their success in controlling
the pest population.
The egg predator Cyrtorhinus lividipennis of BPH had increased instantaneous
attack rates with increasing temperatures until 32°C.
At 35°C the attack rate and handling time decreased drastically.
Natural selection will tend to increase synchrony between hosts and parasitoids.
Asynchrony may occur if host and parasitoid respond differentially to changes
in weather patterns.

38. • Climate change affect the phonology, local
abundance and large scale distribution on plants
and pollination. Insect pollinated plants react more
strongly to increased warming than wind pollinated
plants.
 Quantum of pollination decrease as there is
disruption of natural synchronization between the
flower opening and visit of the pollinators like
honey bees, wasps and butterflies.

39. Increasing spring temperatures may decrease
flower abundance and affect the relative
abundance of pollinator species. . Recent study
says that for every one degree Celsius rise in
temperature there will be 14% loss in butterfly
population.

40. In Britain, Hill et al. (2002)
reported that four butterfly
species had gone extinct at the
southern margins of their
distributions from low
elevation and colonized high
elevation areas, leading to a
mean increase in elevation of
41 m between pre-1970s and
1999.

41. Fine resolution survey in 1km x 1km grid survey in Britain have shown that four
northen/montane butterfly Species had retreated uphill since 1970 (Franco et.
al.,2006).
Erebia epiphron retreated uphill by 130-150 m
without any effect of habitat loss on its distribution.
E.aethiops and Aricia
artaxerxes rettreated
nothward by 70-100 km
and showed combined
impact of climate change
and habitat loss.
Coenonympha tullia declined
through habitat loss but no latiudinal
or elevational shift.

42. Effect of climate change on insect migration can also be analyzed
through light trap data and field observation.
Sparks et.al.,(2007) analyzed the impact of climate on migration of
lepidopteron insect into England from south-west Europe.
The number migratory species was positively related to
temperature anomalies averaged over March to July and it was
suggested that every 1°C increase temperature additional migration
of 14.4±2.4 species to England.

43. Migration of Dragon fly from South India
Millions of dragonflies are flying thousands of miles from India to Africa in the insect
world's longest migration

44. Desert Locust are always present somewhere in the deserts
between Mauritania and India.
If good rains fall and green vegetation develop, Desert
Locust can rapidly increase in number and within a month or two,
start to concentrate, gregarize which, unless checked, can lead to
the formation of small groups or bands of wingless hoppers and
small groups or swarms winged adults.
This is called an outbreak and usually occurs with an area of
about 5,000 sq. km (100 km by 50 km) in
one part of a country.

46. Kiriti (1971) had examined the winter
mortality of adults of Nezara viridula in the
late March at 16 fixed over wintering sites
from 1962 to 1967 in Wakayama.
He suggested that every 1°C rise
in temperature decrease in winter mortality
by about 16.5%

47.  M. Vitrata is becoming predominant insect pest in recent years in all pigeon
pea growing areas of India.
 Maruca has emerged as one of the major constraint because of the
coincidence of high humidity and moderate temperature in September –
October coinciding with the flowering of the crop in India.

48.  Outbreak of S. litura were notice in major sunflower growing areas of
Central and Southern India. During 2005, the outbreak of S. litura led to
more than 90 percent defoliation of sunflower cultivar germplasm.

49.  Invasion of sugarcane woolly aphid, Ceratovacuna lanigera Zehntner in
Maharashtra in 2002 is another example of pest’s reaction to climate change and
getting mostly naturally regulated.
 The aphid appeared in epidemic form in July, 2002 in Sangli Province
of Maharashtra. It spread to other parts of Maharashtra covering an area of 1.43 lakh
ha by March, 2003 and caused upto 30% losses in sugar yield.

52.  Increase in CO2 to 550 ppm increases yields of rice, wheat,
legumes and oilseeds by 10-20%.
10C increase in temperature may reduce yields of wheat,
soybean, mustard, groundnut, and potato by 3-7%. Much
higher losses at higher temperatures.
 Productivity of most crops to decrease only marginally by 2020 but
by 10-40% by 2100.
 Possibly some improvement in yields of chickpea, rabi maize,
sorghum and millets; and coconut in west coast.
 Less loss in potato, mustard and vegetables in north-western
India due to reduced frost damage.

53. Many of the IPM programmes need to be modified greatly or to some extent to
address several important effects of increasing temperatures.
Each new technique recommended has to be evaluated whether and how it suits to
changed pest dynamics due to climate change .
Effects of climate change Revision in IPM recommended
Insect development is more rapid at
higher temperature and population
develops faster and crop damage occurs
more rapidly .
Treatment thresholds based on insects
per plant need to be reduced to prevent
unacceptable loses.
Even modest increase in temperature can
reduce effectiveness of insect
pathogens.(Sharce et al., 2007).
Timing of use of biological control
agents and their amount may need
revision.
Increased winter temperatures and
elimination of frost may allow insect
expansion into new areas.
Such changes should be predicted earlier
and suitable management practices be
introduced.

54. Climate
element
Expected change by 2050 Confidence in
prediction
Effect on agriculture
CO2 Increase from 360 PPM to
450 – 600 PPM
V
ery high Good for crops
Increased photosynthesis
Reduced water use
Sea level rise Rise by 10-15cm V
ery high Loss of land
Coastal erosion
Flooding
Salinization of ground water.
Temperature Rise by 1-2 OC
Increased frequency of heat
waves
High  shorter growing seasons
Heat stress risk
Increased Evapotranspiration
Precipitation Seasonal changes by + or – Low
10%
•Drought
•Soil problem
•Water logging
Storminess Increased wind speeds,
more intense rainfall events
V
ery high Lodging
Soil erosion
Reduced infiltration of
rainfall

55.  New pest outbreak.
 Emergence of new races or biotypes.
 Increase in pest population density .
 More damage by insect pest.
 Secondary pests emerges as major pest and cause more damage.
 Sap sucking pests like aphids, jassids, thrips and whiteflies are major pests and
economically important.
 There is a decline in the pest status of bollworms; the sap feeders, viz. aphids, jassids, mirids
and mealy bugs are emerging as serious pests (Vennila, 2008).
 There are indications of shift of insect pests of plantation crops to new crops and new areas.
 Tea mosquito bug, Helopeltis antonii Signoret is a serious constraint
in cashew (west coast-Kerala, Karnataka, and east coast-Tamil Nadu).

56. •Responses of organisms to climate changes will be species-specific
and might occur at different rates, potentially altering community
structure and the ecological roles of several species in maintaining
ecosystem processes and services.
• Insects have great potential to develop physiological and behavioral
adaptations, which may improve their fitness under new conditions.
•This may ultimately lead to the formation of genetically
differentiated population and possibly new species, especially when
climatic change is associated with range expansion and host switch.
•Biology and life cycles of several arthopods will keep altering under
changes in climate that ultimately could affect many sucessful pest
management practices .

57. •Remote sensing , and GIS system can be helpful in developing
forecasting systems of insect pest. To achieve these goals
entomologist, agro-meteorologist, agronomist and statistician have
to work as a team, only then some workable prediction models can
be developed.
• Best use of the basics of IPM such as field monitoring, pest
forecasting, recordkeeping, and choosing economically and
environmentally sound control measures will be most successful
in dealing with the effects of climate change.
• On the whole, there are still many unknowns in the climate change
equation.