2. Scenario of Insect-pests Under
Climate Change Situation and Future
Challenges in India
Speaker
Ajay Kumar
Seminar In Charge
Dr. Veer Singh
(Prof. & Head)
Department of Entomology
College of Agriculture
Swami Keshwanand Rajasthan Agricultural University, Bikaner-334006
3. Introduction
What is climaticchange?
Impact of climate change on human health
Impact of climate change on agriculture
Impact of climate change on insect pests
Effects of rising temperatureon insectpests
Effects of climate changeon insect pests outbreak
Effects of climate changeon Insect migration & Dispersal
Effects of climate changeon Insect biology & population dynamics
Effects of environmental influence on diapause
Future challenges in India
Conclusion
Future thrust
Content
5. Climate is a measure of the average pattern of variation
in temperature, humidity, atmospheric pressure, wind, precipitation,
atmospheric particle count and other meteorological variables in a
given region over long periods of time.
Monthly global images from NASA Earth Observatory
6. GLOBAL WARMING
is the increase of the
Earth’s average surface
temperature due to a
build-up of greenhouse
gases in the atmosphere.
CLIMATE CHANGE
is a broader term that
refers to long-term
changes in climate,
including average
temperature and
precipitation.
What is the difference between “global
warming” and “climate change”?
7. Climate change refers to a change of climate that is attributed directly or indirectly
by human activity that alters the composition of the global atmosphere and climate
variability observed over comparable time periods.
Climate encompasses the long-run pattern of numerous meteorological factors (e.g.
Temperature, humidity, atmospheric pressure, wind, rainfall, sunshine etc.) in a
given location or larger region. (Gutierrez et al. 2010)
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.
What is Climate Change?
8. These anthropogenic activities are resulting in an
increased emission of active gases, viz. carbon dioxide
(CO₂), methane (CH₄) and nitrous oxide (N₂O),
popularly known as the ‘greenhouse gases’ (GHGs).
Temperature increase to be between 1.1 °C and 6.4 °C by
the end of the 21st Century (IPCC, 2007).
The global warming is expected to lead to other regional
and global changes in the climate-related parameters such
as rainfall, soil moisture, and sea level.
Snow cover is also reported to be gradually decreasing.
9.
10. Causes of climate change
Natural Causes Anthropogenic Causes
1) Continental drift
2) Volcanoes
3) The Earth’s Tilts
4) Ocean Currents
5) Intensity of Solar Radiation
1) Green Houses Gases
Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (NO2)
Chloro floro carbons (CFCs)
Ozone (O3)
Water Vapors (H2O)
2) Land Use Change
Deforestation
Urbanization
13. Monthly average surface temperatures from 1961–1990.
This is an example of how climate varies with location and season.
14.
15. 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.
An increase in atmospheric carbon dioxide level will have a fertilization effect on
crops with C3 photosynthetic pathway and thus will promote their growth and
productivity.
17. Methane emission from rice
cultivation could be alteration in
water management, particularly
promoting mid-season aeration
by short-term drainage;
improving organic matter
management use of rice cultivars
with few unproductive tillers,
high root oxidative activity and
high harvest index.
18. Most efficient management practice to reduce nitrous oxide emission is site-
specific, efficient nutrient management nitrification inhibitors such as
nitrapyrin and dicyandiamide (DCD).
Some plant-derived organics such as neem oil, neem cake and karanja seed
extract which can also act as nitrification inhibitors.
Mitigation of CO₂ emission from agriculture can be achieved by increasing
carbon sequestration in soil through manipulation of soil moisture and
temperature, setting aside surplus agricultural land, and restoration of soil
carbon on degraded lands.
Soil management practices such as reduced tillage, manuring, residue
incorporation, improving soil biodiversity, micro aggregation, and mulching
can play important roles in sequestering carbon in soil.
19. Adaptation Strategies to Climate Change
Developing cultivars tolerant to heat and salinity stress.
Resistant cultivars to flood and drought.
Modifying crop management practices.
Improving water management.
Adopting new farm techniques such as Resource Conserving
Technologies (RCTs).
Crop diversification.
Improving pest management.
Better weather forecasting.
Crop insurance and harnessing the indigenous technical
knowledge of farmers.
Developing Climate-ready Crops.
Diversification of crop and livestock varieties.
22. Insects are the most diverse group of animals on Earth.
An estimated 6-10 million.
An estimated 570,000 species may go extinct by year 2100.
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.
The possible effects of changing climate on insects:
Shift in species distribution range
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
Alterations in crop pest synchrony and natural enemy-pest
interaction (Sutherst,1991; Root et.al.,2003)
23. Change in community structure and extinction of some species are
also expected (Thomas et.al.,2004).
Methods including-
Surveys
Experimental approaches
Modelling approaches have been used to study the impact of climate
change on pest abundance and distribution.
Surveys have been used to delineate climate change impacts on
species distribution range, Phenology, migration and winter survival.
Experimental approaches are also done to check effect of
temperature,CO2 and other climatic factors under controlled
condition.
Modelling approaches allow investigating multiple scenarios and
interactions.
24. 1. Shift in Species Distribution Range
Based on a grid survey (10 km × 10
km) 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.
Regular survey in 11 km × 12 km grids have revealed that in the Czech Republic, the
average altitude for 15 butterfly species had increased significantly between 1950 and
2001 (Konvicka et. al.,2003).
25. 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.
26. 2. Change in Phenology
Recent climate change has led to an ecological shift in time, with changes in species
phenolgy.
Analysis of suction trap
data has revealed that
spring flights of peach
potato aphid(Myzus
persicae) started two
week earlier for every 1°c
rise in tem. Of jan-feb.
Suction traps are being
used to moniter aphids at
the Rothamsted Insect
Survey since 1964.
27. Increasing temperatures have also allowed a number of species to
remain active for a longer period during the year or to increase their
annual number of generation.
Under the AICRIP of ICAR collect light trap data round the year
provide important information on the impacts of climate change
impacts on rice pests.
28. 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.
3.Insect Migration
29. 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
30. 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.
Potential migration of Desert Locust
31.
32.
33. Winter Mortality
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%
34. B. Experimental approaches
Figure : Temperature ranges in relation to insect development (LL –
Lower lethal, LT- Lower threshold, UT- Upper threshold, UL- Upper lethal)
The potential impact of temperature rise on pest prevalence can be known
by comparing the current and projected temperature conditions at a
location with pest’s favourable temperature range
35. A pair of observations on temperature and the corresponding development
period can be used for determining the threshold of development or lower
threshold (LT) as follows:
LT = (T1×D1 – T2×D2) / D1–D2
where, T1 and T2 are two temperatures and D1 and D2 are the
corresponding development periods.
Thermal constant for a particular development stage can be calculated by
summing the effective temperatures for the entire duration of development
of a particular development stage and consequently, the whole life-cycle.
36. Potential Increase in Number of Generations
and Density of Insects
Information on threshold of development and thermal constant can also be
used to determine the impact of climate change on the number of generations
and density of an insect species.
The number of generations per year is one of the most important parameters
that affect the abundance of multivoltine species.
Yamamura and Kiritani (1998) have proposed an analytical method to estimate
the potential increase in the number of generations under global warming in
temperate zones.
dN = dT (206.7 + 12.46 (m–T₀))/K
where,
dN = Potential increase in the number of generations in a year under global
warming;
dT = Increase in the annual mean temperature due to global warming
m = Annual mean temperature (oC)
T₀ = Lower developmental threshold temperature
37. Direct Impact of Temperature on Insect-pest
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
38. Common
Name Scientific Name Temperature
Range
Biology Temperature Biology References
Argentine
ant
Lithepithema
humile
<18°C(64.4F) egg laying
ceases
6°C (42.8F) Activity
ceases
Ebeling 1975
Cat flea Ctenocephalides
felis
130C (55.4F) egg hatch
( 6days)
35°C (95F) egg hatch
(36 hours)
Silverman et al.
1981
House fly Musca domestica <200C (68F) larval stage
6-8 weeks
21-32°C (69.8-
89.6F)
larval stage
3-7 days
Ehmann 1997
Indian meal Plodia
interpunctella
200C (68F) moth life
cycle(60days)
25°C (77F) life cycle
(30 days)
Cox and Bell
1991
Yellow fever
mosquito
Aedes aegypti 25-29°C
(77-84.2F)
optimum larval
development
26°C (78.8F) optimal adult
temperature
Fay 1964
Effects of Temperature on Insect Biology
39.
40. Effect of elevated CO2 on insects
Impact of CO2 on insect population via host plants can be studied through
open top chambers (OTCs) and free air carbon dioxide enrichment (FACE).
OTCs are essentially plastic enclosures placed around a sample of an
ecosystem.
Air is drawn into a box by a fan, enriched with CO2, and blown through the
chamber.
Open-top chambers are relatively inexpensive to build because they consist
simply of an aluminium frame covered by panels of polyvinyl chloride
plastic film.
The FACE technology facilitates modification of the environment around
growing plants to future concentrations of atmospheric CO2 under natural
conditions of temperature, precipitation, pollination, wind, humidity, and
sunlight.
FACE field data represent plant responses to concentrations of atmospheric
CO2 in a natural setting
41.
42. Free air carbon dioxide enrichment (FACE) apparatus
used for pure CO2 injection in the field
43. Gao et al. (2008) used OTCs to examine interactions across three trophic
levels, cotton (Gossypium hirsutum), aphid (Aphis gossypii) and its
coccinellid predator (Propylaea japonica), as affected by elevated CO2
concentrations and crop cultivars.
Two levels of CO2, viz. ambient (375 ppm) and double the ambient (750
ppm) were used.
Plant carbon:nitrogen (C:N) ratios, condensed tannin, and gossypol
content were significantly higher while nitrogen-content was significantly
lower in the plants exposed to elevated CO2 levels compared to those
exposed to ambient CO2.
Cotton aphid survival significantly increased with increased CO2 conc.
A. gossypii may become a more serious pest under an environment with
elevated CO2 concentrations because of increased survivorship of aphid
and longer development time of lady beetle.
44. Hamilton et al. (2005) used the FACE technology to create an atmosphere with CO2
and O2 concentrations similar to those predicted for the middle of the 21st century.
During the early season, soybean grown under the elevated CO2 atmosphere had
57% more damage from the insects like Japanese beetle, potato leafhopper, western
corn rootworm and Mexican bean beetle.
Measured increases in the levels of simple sugars in the soybean leaves might have
stimulated the additional insect feeding.
Rao et al. (2009) have conducted feeding trials with two foliage feeding insect
species, Achaea janata and Spodoptera litura using foliage of castor plants grown
under four concentrations of CO2, viz. 700 ppm,550 ppm,350 ppm and ambient CO2
in the open.
Compared to the larvae feed on the ambient CO2 foliage, the larvae feed on 700 ppm
and 550 ppm CO2 foliage exhibited higher consumption.
The 700 ppm and 550 ppm CO2 foliage was more digestible with higher values of
approximate digestibility.
45. Effect of elevated CO2 on insects
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
47. Papaya mealy Bug
(Paracoccus marginatus)
Incidence and severity of papaya mealy bug, Paracoccus marginatus
on cotton with its expanding host range across crops of industrial
importance viz., cotton, mulberry, tapioca, papaya and jatropha was
found in Tamil Nadu.(Anonymous,2010)
The Papaya mealy bug has caused havoc in agricultural and
horticultural crops, ever since its first report from Coimbatore in 2007
.
In 2009 it caused severe damage to economically important crops and
huelosses to farmers in Coimbatore, Erode, Tirupurand Salem districts
of Tamil Nadu.
In the same year, standing mulberry crop over 1,500 hectares in
Tirupura was destroyed by the pest.
Recently noticed in Karnataka, certain parts of Andhra and
Mallapuram and Thrissurdistricts of Tamil Nadu.
48. 1
3
4
1 –Adults of papaya mealy bug
2 –on Congress grass
3 –on Papaya
4 –on Cotton
49. Tobacco caterpillar (Spodoptera litura)
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
than30 per cent cotton leaves at elevated CO2 levels (Kranthi et al., 2009).
50. 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.
51. 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.
Sugarcane wooly aphid
(Ceratovacuna lanigera)
52. Maruca vitrata (Geyer)
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.
53. Influence of photoperiod on egg
diapause in two moth speices.
Influence of food quality and day length
on diapause behavior in the Colorado
potato beetle.
from Chapman 1971
The diapause cue may be experienced by
the previous generation, so the mother
insect may be cued to lay eggs that will
diapause or not.
54.
55. Effect of Rainfall
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
relationship between outbreaks of
armyworm and to a lesser extent
Spodoptera mauritia (Boisd.) and
rainfall from 1938 to 1965 and observed
that all but three outbreaks occurred
when rainfall exceeded the average 89
cm.
56. 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
patterns of the desert locust
(Schistocerca gregaria).
Helicoverpa armigera damage
severity showed higher November
rainfall favoured higher infestation.
57. Effect of Climate on Pest Population via
Natural Enemies
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.
58. Agriculture
•Up to 50% reduction in maize yields
•4-35% reduction in rice yields (with some exceptions)
•Rise in coconut yields (with some exceptions); reduced apple production
•Negative impacts on livestock in all regions
Fresh water supply
•High variability predicted in water yields (from 50% increase to 40-50%
reduction)
•10-30% increased risk of floods; increased risks of droughts
Forests and natural ecosystems
•Increased net primary productivity
•Shifting forest borders, species mix, 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
Effects of climate change in India
59. Future challenges in India
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).
60. Adaptation Measure for Climate Change
Integrated pest management
Using available early warning system for insect pest.
Biological control measures.
Utilization of indigenous traditional knowledge base for
Pest control.
Soil solarization technique.
Breeding for pest, disease and drought resistance
varieties.
Careful tracking of geographical distribution of pest.
Phytosanitary regulations to prevent or limit the
introduction to risky insect pest.
61. Current strategies for management need to modified
accordingly.
Development and validation of weather based pest-
disease forecasting models for Indian condition to serve
as early warning systems.
Breeding for pest-disease tolerant cultivars needs to be
initiated.
Studies needs to be initiated on changes in host
physiology, pest life cycle and host pest interaction caused
by changing climatic parameters.
Future thrust
62. Conclusion
The greatest challenge facing humanity in the coming century will be
the necessity to double our global food using less land area, less
water, less soil nutrients, droughts from global warming.
The exact impacts of climate change on insects and pathogens are
rather uncertain.
Climate change being is a gradual process will give us opportunities to
modify our agricultural practices.
Basics of IPM practices such as field monitoring, pest forecasting,
record keeping, and choosing economically and environmentally
sound control measures would helps in dealing with the effects of
climate change.
Understanding how climate change will impact on various pests
especially crop pests helps agricultural scientist to orient their
research on various futuristic possibilities that can help in mitigating
and adapting to menace of anticipated climate change.
