Invited lecture to MPKV trainees

Dr. Babasaheb B. Fand Scientist (Agril. Entomology)

Abiotic stresses affecting crop-insect pest interactions in the context of global climate

change

राष्ट्रीय अजैवि�क स्ट्रैैस प्रबंधन संस्थानNational Institute of Abiotic Stresses Management


Every life in nature is dependent on some another life


Agro-ecosystem environment


Abiotic

Biotic

राष्ट्रीय अजैवि�क स्टै्रस प्रबंधन संस्थानNational Institute of Abiotic Stresses Management

(Source: Buchanan, Gruissem & Jones, 2000: Biochemistry and Molecular Biology of Plants; American Society of Plant Physiologists,)

Agricultural yield losses due to abiotic and biotic stresses

Corn Wheat Soybean Sorghum Oat Barley

020406080

100120140160180200

Series4Abiotic stressesBiotic stresses

Crops

Yie

lds

(Qtls

/ha) Record yield

Influencing crop growth and productivity to the extent of 80%

These yield losses are likely to be aggravated with impending climate change

• An issue of global concern• Increasing levels of Global atmospheric

Temperature : 0.80CCO2 : 370 ppm

• Alarming signals about rapid environmental change • Profound effects on many biological systems • Serious effects on agricultural production & livelihood of farmers• Climate sensitive sectors : Agriculture

Forestry Livestock Fisheries

Climate change and global warming



• 0.56°C rise in annual mean temperature over last 100 yrs• Worst droughts yrs: 1971-72, 1999-2000 & 2000-2002 • Increased intensity of rainfall• Decrease in number of rainy days • Prolonged dry spells

(IMD, 2006, 2007, 2009)

• Phenomenal effect on incidence of major crop pests

Climate change and India

Contribution of different sectors in India to climate change


Industrial processes

8%

Wastes2%

Land use changes

1%

Agriculture28%

Energy61%

Source: India’s Initial National Communication on Climate Change, 2004


Contribution of Agricultural sectors to Climate change

Rice cultivation23%

Manure management

5%

Emission from soils12%

Enteric fermentation

59%

Crop residues1%

Source: India’s Initial National Communication on Climate Change, 2004

• Increased urbanization• Deforestation• Industrialization


Major drivers of Climate change

Overexploitation and misuse of natural resources for various anthropogenic developmental activities

Yield Productivity

Area


Excessive pesticide Use

Habitat alteration

Changes in cropping practices : Bt cotton

Suppression of Competitor

species

Outbreaks

Extinction of many insect species

Major pestsMinor pests

Destruction of natural enemies


Impact negatively the diversity and abundance of insect pests

Increasing the extent of crop losses

Upsetting ecological balance

Unpredictable changes in the abundance of insect-pests and their existing and potential natural enemies

(Ball, 1997; Rao et al., 2006; IPCC, 2007)

Climate change and Insects

• Loss of ecological biodiversity• Expansion of geographic ranges• Increased overwintering survival• Increase in number of generations per season• Impact on pest population dynamics and outbreaks• Breakdown of host plant resistance to insects• Impact of increased CO2• Reduced effectiveness of biocontrol agents• Disruption of plant-pollinator interactions


Insect-pests in the era of climate change


1. Loss of ecological Biodiversity

• Biological wealth of habitat

• Species richness in an ecosystem

India: - One of the 12 mega-biodiversity centres - Three out of 34 biodiversity hotspots

• Plays a major role in climate regulation

• Human pressure on ecosystem accelerating the rate of extinction of life on earth

• Climate change- dominant direct driver of biodiversity loss by the end of century

(Myers et al., 2000; UN-HABITAT, 2004; Millennium Ecosystem Assessment report, 2005; Murugan, 2006)


Insect Biodiversity

Most diverse group of animals (80%) Integral component of ecological cycles Very good indicators of environmental change Play an important role in food chains Excellent pollinators for many of the economically important crops

राष्ट्रीय अजैवि�क स्ट्रैसै प्रबंधन संस्थानNational Institute of Abiotic Stresses Management

Indian Insect fauna

Western Ghats in IndiaThe only habitat to many rare, endemic and exotic species of colourful butterflies in the worldMany butterfly species are under a real threat due to depletion of the natural vegetation for various anthropogenic developmental activities

About 6.83% of world insect species are inhabitant in India


More than one-third of species in the world are at the risk of extinction

Up to 50% of the Asia’s total biodiversity is at risk due to climate change

Many other species could also be extricated as a result of the climate change and habitat fragmentation

Number of threatened animal species per group(Source: IUCN threat categories, 1994)

(Insects, nematodes, earthworms, crustaceans, spiders etc)


What are the implications ????Loss of biodiversity

Ecosystem

Structure Composition Function

Wildlife habitat

Outbreaks of destructive insect-pests and diseases

-ve impacts


2. Expansion of geographic ranges

Geographic distribution and abundance of

organisms

Regional/ local

climate

Growth, survival

Reproduction

Altered temperature and rainfall regimes with the predictable changes in climate will determine the future distribution, survival and reproduction of the species


Increased temperature

Altitude wise shift in cultivation areas of crop plants

Increased abundance of tropical insect species

Expansion of geographic range of insect-pests

Local extinctions

Inhospitable conditions

Sudden pest outbreak

Heavy losses in crop yield


Predicted range expansions with Global warming

The rise in temperature due to global warming has shifted apple cultivation in Himachal Pradesh from Lower areas of Kullu & Mandi districts to higher altitude in Lahaul & Spitti

Rana et al., 2008

The associated insect-pests may also extend their geographic range along with the host plants


Predicted range expansions with Global warming

Corn earworms in USAHeliothis zea (Boddie)

Helicoverpa armigera (Hubner) (EPA, 1989; Diffenbaugh et al., 2008)

Helicoverpa armigera (Hubner) A major pest of cotton, pulses and vegetables in North India

(Sharma et al., 2005; Sharma, 2010)


3. Increased overwintering survival

Insects (Poikilotherms)

Behavioural avoidance through migration

Limited ability of homeostasis

Adaptation strategies to support life under thermally stressful environments

Diapause (Physiological)

-- Seasonal regulation of insect life cycles -- Survival under environmental adversities

राष्ट्रीय अजवैि�क स्ट्रैसै प्रबंधन संस्थानNational Institute of Abiotic Stresses Management


Accelerated metabolic activities

Early resumption of active growth

Early termination of diapause

Winter

Faster nutrient depletion

Increased population built-up

Heavy losses in crop yield

Delay in onset of diapause

Summer

low winter mortality

Increased insect survival

Early infestations


4. Increase in number of generations per season

Capacity to complete more number of generations per year / season


Accelerated rates of development, reproduction and survival

More crop damage


5. Impact on pest population dynamics and outbreaks

Changes in climatic variables have led to increased frequency & intensity of outbreaks of insect-pests • Wooly aphid in Sugarcane

• Brown plant hopper in Rice• Cotton mealybug• Papaya mealybug• Coconut mite


Sugarcane wooly aphid, Ceratovacuna lanigera Zehntner (2002-03)

• Sugarcane belt of Maharashtra and Karnataka• Resulted in 30 % yield losses

(Joshi and Viraktamath, 2004; Srikanth, 2004; 2007; Tripathi et al, 2008; Rafee, 2010)


Brown plant hopper, Nilaparvata lugens in Rice (2008-09)

Hopper Burn symptoms

• Northern rice growing region of India• Significant damage to high value Basmati rice• Affected rice crop over 33,000 ha

IARI News, 2008. Brown plant hopper outbreak in rice. 24(Oct-Dec): 1-2.

Major havoc to the cotton crop in India: 2006-07(Dhawan et al., 2007; Gautam, 2007, 2008; Tanwar et al., 2007, Jhala et al., 2008; Bhosle et al., 2009)

Economic impact of P. solenopsis flare up on Indian Agriculture30-40 % yield loss in cotton

Pesticide sale over Rs 500 crores in Punjab

Cost of plant protection increased by Rs 2500/ acre

Mealybug took away the glory of Bt cotton

Made another big hole in the pocket of the already distressed farmers (Dhawan et al., 2007; Gautam, 2007, 2008; Jhala et al., 2008)

Cotton mealybug Phenacoccus solenopsis Tinsley



Papaya mealybug, Paracoccus marginatus (2009-10)

Major havoc to papaya growers in Tamil Nadu, Karnataka & Maharashtra

NCIPM, 2009, 2010; NBAII, 2010


6. Breakdown of host plant resistance to insects

Weakening of plants’ own defensive system

Environmental factors Temperature Sunlight Soil moisture Air pollution

Host Plant Resistance

Increased susceptibility to attack by insect pests

Pest outbreaks and more crop damage

Impact on secondary metabolic pathways(SA, JA)


Breakdown of resistance (Midge Stenodiplosis sorghicola (Coq.) &

Spotted stem borer Chilo partellus Swinhoe)

Severe yield loss in sorghum

(Sharma et al., 1999; 2005)

Transgene expression in Bt cotton

Reduced production of Bt toxins

Enhanced susceptibility of the cotton to Bollworm Helicoverpa armigera (Hubner)

(Kaiser, 1996; Hilder and Boulter, 1999)

Temperature and water stress


7. Impact of increased CO2

(Lincoln, 1984; 1993; Bazzaz and Fajer, 1992; Coviella and Trumble 1999, Hunter 2001)

CO2 enriched environment

Reduced nitrogen content of plant tissue

Widening of C: N ratio.

Enhanced feeding by insects

Slows down the insect development

Increases the length of life stages

More crop damage than the normal


8. Reduced effectiveness of biological control agents

Hosts escape at higher temperaturesReduced window of opportunity for parasitism Great set back to the survival and multiplication of parasitoids

Natural enemies of crop pests : predators, parasitoids & pathogensDensity responsive subjected to the action of abiotic components

Tiny and delicateMore sensitive to the climatic extremes like heat, cold, wind & rains

Host - NEsDifferential response to changing climate


9. Disruption of plant-pollinator interactions

Entomophilies pollination:A fundamental process essential for the production of about one-third of the world human food

Important insect pollinatorsBees, flies, butterflies, moths, beetles, etc.

Insect pollination, mostly by bees, is necessary for reproduction and formation of fruits and seeds in about 75% of crops

(Ingram et al., 1996; Klein et al., 2007; Ricketts et al., 2008)


-ve impacts of climate change on pollinatorsDeclining population abundanceShift of geographic rangeDeclining pollination activities

(Klusser et al., 2007; FAO, 2008)

Pollination is one of the major ecosystem services currently under threat from mounting pressures exerted by growing population, depleting natural resource base and global climate change (Costanza et al., 1987; MEA, 2005; Sachs, 2008)


Temperature and water availability

Impact on critical events in the life cycle of plants (flowering, pollination, fruiting & seed set)

Disruption of the synchrony between plant-pollinator relationships

Impact on extent, quality & quantity of pollination

Multiple implications for food security, species diversity, ecosystem stability and resilience to

climate change

Changing climate regimes

(Cleland et al., 2007; (Kudo et al., 2004; Deustch et al., 2008; FAO, 2008)


Socio-economic impacts

Implications for food security


(Patterson et al., 1999; Gutierrez, 2000; Klein et al., 2007; FAO, 2008; IPCC, 2007; Chahal et al., 2008).

Aggravating pest problems

Intensification of the agricultural yield losses

Threat to the food & nutritional security

Disruption of the plant-pollinator interactions

Changing climate regimes

Reduced crop pollination

Reduction in food production


Implications for farming community

• Need to take care of more types and more number of insects• Reduced effectiveness of pest management strategies/ pesticides• Frequent pesticide applications• Increased cost of plant protection• Impact on livelihood of the rural poor • Increased food prices resulting from declining food production


Breeding climate-resilient varieties

• To breed new varieties for improved resistance to biotic and biotic stresses

• Considering late onset and shorter duration of winter, there is chance of delaying and shortening the growing seasons for Rabi/ cold season crops like wheat

• Breeding varieties suitable for late planting and those can sustain adverse climatic conditions

Challenges ahead


Rescheduling of crop calendars

• Certain effective cultural practices like crop rotation will be less or no effective with changed climate

• Global temperature increase may result in shrinking of crop growing seasons, hence there is need to change the crop calendar according to the changing crop environment

• The growers of the crops have to change insect management strategies in accordance with the projected changes in pest incidence and extent of crop losses in view of the changing climate


Developing temperature based phenology models for pests & diseasesThe forewarning models for predicting insect arrival/ infestations based on earlier climate profiles need to be revised in accordance with location specific changes in climate in order to provide precise and accurate forecast of the pest incidence

GIS based risk mapping of crop pests• Agro-ecological hot spot zonation• Delineation of future areas of pest risk

Weather-based Apple fire blight risk mapping in GIS


Adaptation/ mitigation of agriculture to changing pest scenario due to climate

Strengthen research for enhancing adaptive capacity:• Pest surveillance for improved assessments in advance of outbreaks• Research focus on the search for more general forms of resistance against various classes of insects or diseases• Developing mechanisms for collection and disseminating information on insect- pest data in different environmental situations


Sensitization of stakeholders about climate change and its impacts• Training and capacity-building of extension worker, farmers & other stakeholders involved in supply chain management• Development of learning material and support guides for different risk scenarios in the contexts of pest outbreaks in agriculture sector• Assist farmers in coping with current climatic risks through weather services, agro- advisories, insurance, community banks, etc


Promotion of resource conservation technologies • Incentives to farmers for resource conservation and use efficiency (Bio- control, Integrated Pest Management)• Subsidies for adaptation of environmental conserving pest controlling technologies, pest based Agri-Insurance• Strategies for adaptation and coping could benefit from combining scientific and indigenous knowledge, especially in developing countries where technology is least developed• Further more study towards integrating indigenous adaptation measures in global adaptation strategies and scientific research


Is it possible to stop climate change ?????

Most of the researchers agree that the current warming trend can’t be stopped or reversed but that it can be slowed down to allow the biological systems and human society to adapt

Conclusions


• Being a tropical country, more challenged with impacts of looming climate change

• Differential impacts of abiotic factors such as temperature, humidity &rainfall• Varied pest damage in different agro-climatic regions across the country

• Intensification of yield losses due to potential changes in crop diversity and increased incidence of insect-pests• Serious environmental and socioeconomic impacts on rural farmers whose livelihoods depend directly on the agriculture• Urgent need to modify crop protection measures with changed climate in order to attain the goal of food security of the nation • Need for careful attention in planning and devising adaptation and mitigation strategies for future pest management strategies

Implications for India


Education

Invited lecture to MPKV trainees