What is an Economic Threshold Level (ETL) and why does it matter?

The Economic Threshold Level is the pest population density at which control measures should be initiated to prevent the pest from reaching the Economic Injury Level — the point where the cost of damage exceeds the cost of control. ICAR institutes such as ICAR-IIRR (Hyderabad) publish crop-and-pest specific ETLs (for example, around 10 brown planthoppers per hill in rice at the tillering stage). Spraying only after the ETL is crossed avoids unnecessary insecticide use, conserves natural enemies and slows the development of resistance.

How do pheromone traps work and where are they recommended?

Pheromone traps use a synthetic version of the species-specific sex pheromone released by female moths to lure male moths into a trap, allowing both monitoring of pest activity and, at higher densities, mass trapping. ICAR-NBAIR and NCIPM recommend pheromone traps as a core monitoring tool for Pink Bollworm in cotton (gossyplure), Fall Armyworm in maize, Yellow Stem Borer in rice (Scirpolure) and Tuta absoluta in tomato, with trap counts used to time scouting and need-based sprays.

Which biocontrol agents are widely used in Indian crop protection?

Egg parasitoids of the genus Trichogramma (T. chilonis, T. japonicum, T. pretiosum) are mass-reared and released in rice, sugarcane, cotton and maize against stem borers and lepidopteran caterpillars. Nucleopolyhedrovirus (NPV) formulations are available against Helicoverpa armigera and Spodoptera litura. Predators like Chrysoperla, parasitoids such as Bracon and microbial agents like Trichoderma (against soil-borne diseases) are produced at ICAR-NBAIR and at state biocontrol laboratories.

Why should farmers rotate pesticide chemistries?

Repeated use of insecticides or fungicides from the same mode-of-action group rapidly selects for resistant populations — already documented for Pink Bollworm against Bt cotton and for several Helicoverpa populations against pyrethroids. Rotating between distinct mode-of-action groups (as classified by IRAC for insecticides and FRAC for fungicides), combined with non-chemical IPM tactics, slows resistance evolution. All pesticide use must follow the latest CIBRC (Central Insecticides Board & Registration Committee) approved label, dose and pre-harvest interval.

Where should a farmer report a suspected new pest outbreak?

Farmers can call the Kisan Call Centre toll-free on 1800-180-1551 (operated by the Department of Agriculture & Farmers Welfare) for advisory support, contact their nearest Krishi Vigyan Kendra or state agriculture department, and use the Plant Pest Surveillance functionality on the National Pest Surveillance System operated by NCIPM. Suspected invasive species can also be reported to ICAR-NBAIR (nbair.res.in), which coordinates national insect biosystematics and biocontrol responses.

Pest & Disease Identification Quick Reference — Major Indian Crop Pests and Diseases

This page is a quick-reference field guide to some of the most economically important pests and diseases of Indian crops, with identifying symptoms and monitoring or management notes drawn from advisories of the Indian Council of Agricultural Research (ICAR) and its specialised institutes — ICAR-NBAIR (Bengaluru), ICAR-NCIPM (New Delhi), ICAR-IIRR (Hyderabad), ICAR-IIHR (Bengaluru), ICAR-IIWBR (Karnal) and ICAR-CPRI (Shimla) — together with information disseminated through the national network of Krishi Vigyan Kendras.

Pair scouting and trap-based monitoring with seasonal planning using our India crop calendar: knowing the sowing and critical-growth windows for each crop is essential for timing pest surveillance and for setting up pheromone traps before the egg-laying flush. Farmers should also be aware of the institutional support available through government schemes — soil-health-card based balanced nutrition, Kisan Credit Card-financed inputs and PMFBY crop insurance can together cushion both the cost and risk of pest and disease outbreaks. Where stubble harbours carry-over insect populations — most notably Pink Bollworm in cotton residue and Yellow Stem Borer in paddy stubble — read our crop residue management guide for non-burning sanitation alternatives. The government institute that trains state plant-protection officers and Farmer Field School facilitators on this IPM stack — and technically anchors the Central IPM Centres (CIPMCs) that produce and supply the biocontrol agents referenced below — is NIPHM at Rajendranagar, Hyderabad; the framework this page operationalises — five pillars, ETL discipline, biocontrol stack and Farmer Field School delivery — is covered in our Integrated Pest Management (IPM) guide. For deeper crop-specific agronomy, see our knowledge base.

Major pests & diseases

Pink Bollworm (Pectinophora gossypiella)

Host crop: Cotton

Identifying symptoms: Larvae bore into squares, flowers and bolls; affected bolls show characteristic exit holes, rosetted ("rosette") flowers and stained, locule-trapped lint with damaged seeds.

Monitoring & management: ICAR-CICR (Nagpur) and NCIPM advisories recommend pheromone-trap based monitoring (gossyplure traps at 5/ha), timely terminal-flowering surveys, destruction of crop residue and stubble, and need-based use of approved insecticides; field reports of resistance in Bt (Bollgard-II) cotton across central and southern India make trap-based scouting and crop sanitation especially critical.

Reference: ICAR-CICR

Fall Armyworm (Spodoptera frugiperda)

Host crop: Maize (also sorghum, sugarcane)

Identifying symptoms: Young larvae cause window-pane scraping on leaves; older larvae produce ragged, elongated holes and copious moist sawdust-like frass in the whorl, with characteristic four dark spots in a square on the second-last abdominal segment.

Monitoring & management: First reported in India from Shivamogga, Karnataka in May 2018; ICAR-NBAIR and NCIPM advisories recommend weekly egg-mass and whorl scouting, pheromone traps for monitoring, mass release of Trichogramma pretiosum egg parasitoids, conservation of native predators, and need-based application of approved insecticides as per the Directorate of Plant Protection advisory.

Reference: ICAR-NBAIR

Brown Planthopper (Nilaparvata lugens)

Host crop: Rice

Identifying symptoms: Dense colonies of brown sap-sucking hoppers at the base of tillers cause yellowing, stunting and circular patches of completely dried plants known as "hopper burn"; plants may also show sooty mould and a sticky honeydew layer.

Monitoring & management: ICAR-IIRR (Hyderabad) sets the economic threshold at around 10 hoppers per hill at the tillering stage and recommends avoiding indiscriminate early-season insecticide use, maintaining alleyways for monitoring, draining the field for 3–4 days, growing resistant varieties, and need-based use of recommended insecticides only when the threshold is crossed.

Reference: ICAR-IIRR

Yellow Stem Borer (Scirpophaga incertulas)

Host crop: Rice

Identifying symptoms: Larvae bore into the central shoot causing "deadheart" — the central whorl drying up and pulling out easily — during the vegetative stage; at panicle initiation and flowering the same damage produces empty, whitish "whitehead" panicles.

Monitoring & management: ICAR-IIRR and state advisories recommend pheromone-trap based monitoring (Scirpolure traps), light traps for moths, removal and destruction of stubble after harvest, mass release of Trichogramma japonicum at 1 lakh/ha/week from 30 days after transplanting, and need-based use of recommended granular or systemic insecticides.

Reference: ICAR-IIRR

South American Tomato Leafminer (Tomato Pinworm) (Tuta absoluta)

Host crop: Tomato

Identifying symptoms: Larvae mine within leaves producing irregular blotch-shaped, translucent mines that later turn brown and necrotic; they also bore into stems, flowers and developing fruits, leaving small entry holes and frass-filled galleries.

Monitoring & management: Invasive in India since first detection at Pune in 2014; ICAR-IIHR (Bengaluru) and NCIPM advisories recommend pheromone trap monitoring (TLM lure water traps at 25/ha as mass trapping or 4–5/ha as monitoring), removal and destruction of infested plant material, use of yellow sticky traps, and conservation of natural enemies along with need-based application of approved insecticides on rotation.

Reference: ICAR-IIHR

Mango Hopper (Idioscopus spp. (I. niveosparsus, I. clypealis, Amritodus atkinsoni))

Host crop: Mango

Identifying symptoms: Wedge-shaped adults and nymphs cluster on inflorescences and tender shoots; sap-sucking causes flower drop, blackened panicles and copious sticky honeydew on leaves and fruits, often followed by sooty mould development.

Monitoring & management: ICAR-IIHR advisories recommend pre-flowering pruning of dense canopies to reduce humidity and resting sites, monitoring panicles from bud-burst, and at most two need-based sprays — typically one at panicle emergence and another after fruit-set — with approved insecticides on rotation; routine calendar sprays are discouraged to conserve pollinators and natural enemies.

Reference: ICAR-IIHR

Wheat Yellow (Stripe) Rust (Puccinia striiformis f. sp. tritici)

Host crop: Wheat

Identifying symptoms: Lemon-yellow to bright yellow uredinial pustules arranged in linear stripes between veins on leaves, leaf sheaths and occasionally glumes; severely affected fields show a yellow-orange cast, premature drying and shrivelled grains.

Monitoring & management: ICAR-IIWBR (Karnal) operates a national wheat-rust surveillance programme tracking pathotype dynamics, particularly in the northern hill and north-western plains zones; advisories recommend timely sowing, growing notified rust-resistant varieties suited to the zone, regular field scouting from tillering onwards, and a need-based foliar spray of an approved triazole fungicide such as propiconazole 25 EC at first appearance of pustules.

Reference: ICAR-IIWBR

Late Blight (Phytophthora infestans)

Host crop: Potato (and tomato)

Identifying symptoms: Water-soaked, irregular pale-green to brown lesions begin on lower leaves and rapidly enlarge; in cool, humid weather a delicate white sporulating mould appears on the underside of lesions and tubers develop coppery-brown, granular dry rot beneath the skin.

Monitoring & management: ICAR-CPRI (Shimla) operates a national late-blight forecasting system (Indo-Blightcast / JHULSACAST) and issues regional advisories; risk peaks in cool (10–24 °C) humid weather. Recommended practice is the use of healthy, certified seed tubers, ridging to reduce tuber infection, prophylactic protectant fungicide sprays (e.g., mancozeb) in disease-conducive weather, and switching to systemic fungicides on rotation once the disease is detected.

Reference: ICAR-CPRI

FAQs

What is an Economic Threshold Level (ETL) and why does it matter?: The Economic Threshold Level is the pest population density at which control measures should be initiated to prevent the pest from reaching the Economic Injury Level — the point where the cost of damage exceeds the cost of control. ICAR institutes such as ICAR-IIRR (Hyderabad) publish crop-and-pest specific ETLs (for example, around 10 brown planthoppers per hill in rice at the tillering stage). Spraying only after the ETL is crossed avoids unnecessary insecticide use, conserves natural enemies and slows the development of resistance.
How do pheromone traps work and where are they recommended?: Pheromone traps use a synthetic version of the species-specific sex pheromone released by female moths to lure male moths into a trap, allowing both monitoring of pest activity and, at higher densities, mass trapping. ICAR-NBAIR and NCIPM recommend pheromone traps as a core monitoring tool for Pink Bollworm in cotton (gossyplure), Fall Armyworm in maize, Yellow Stem Borer in rice (Scirpolure) and Tuta absoluta in tomato, with trap counts used to time scouting and need-based sprays.
Which biocontrol agents are widely used in Indian crop protection?: Egg parasitoids of the genus Trichogramma (T. chilonis, T. japonicum, T. pretiosum) are mass-reared and released in rice, sugarcane, cotton and maize against stem borers and lepidopteran caterpillars. Nucleopolyhedrovirus (NPV) formulations are available against Helicoverpa armigera and Spodoptera litura. Predators like Chrysoperla, parasitoids such as Bracon and microbial agents like Trichoderma (against soil-borne diseases) are produced at ICAR-NBAIR and at state biocontrol laboratories.
Why should farmers rotate pesticide chemistries?: Repeated use of insecticides or fungicides from the same mode-of-action group rapidly selects for resistant populations — already documented for Pink Bollworm against Bt cotton and for several Helicoverpa populations against pyrethroids. Rotating between distinct mode-of-action groups (as classified by IRAC for insecticides and FRAC for fungicides), combined with non-chemical IPM tactics, slows resistance evolution. All pesticide use must follow the latest CIBRC (Central Insecticides Board & Registration Committee) approved label, dose and pre-harvest interval.
Where should a farmer report a suspected new pest outbreak?: Farmers can call the Kisan Call Centre toll-free on 1800-180-1551 (operated by the Department of Agriculture & Farmers Welfare) for advisory support, contact their nearest Krishi Vigyan Kendra or state agriculture department, and use the Plant Pest Surveillance functionality on the National Pest Surveillance System operated by NCIPM. Suspected invasive species can also be reported to ICAR-NBAIR (nbair.res.in), which coordinates national insect biosystematics and biocontrol responses.

Sources & further reading

ICAR-NBAIR — National Bureau of Agricultural Insect Resources, Bengaluru: insect biosystematics, biocontrol agents and invasive-species advisories.
ICAR-NCIPM — National Centre for Integrated Pest Management, New Delhi: crop-wise IPM packages and pest surveillance.
ICAR-IIRR — Indian Institute of Rice Research, Hyderabad: rice pests, diseases and economic threshold guidance.
ICAR-IIHR — Indian Institute of Horticultural Research, Bengaluru: horticultural pest and disease advisories.
ICAR-IIWBR — Indian Institute of Wheat and Barley Research, Karnal: wheat-rust surveillance and zonal recommendations.
ICAR-CPRI — Central Potato Research Institute, Shimla: late-blight forecasting and potato disease advisories.
ICAR Krishi Portal and the network of Krishi Vigyan Kendras.
Kisan Call Centre toll-free helpline: 1800-180-1551.

Disclaimer:this page is a quick reference and is not a substitute for local advice from a Krishi Vigyan Kendra or the state department of agriculture. Pest pressures, recommended varieties and approved chemistries vary by agro-ecological zone and season; pesticide use must follow the latest CIBRC (Central Insecticides Board & Registration Committee) approved label, dose and pre-harvest interval.