This presentation covers the major insect pests of tomato, focusing on their identification, biology, nature of damage, and management strategies. Emphasis is placed on integrated pest management (IPM), including biological, cultural, and chemical control methods. Key pests discussed include the tomato fruit borer, serpentine leaf miner, whitefly, aphids, thrips, and red spider mite. Understanding pest life cycles and damage symptoms is essential for effective control and sustainable tomato production. Important academic keywords include Helicoverpa armigera, integrated pest management, biological control, vector, and resistant varieties.
Introduction to Tomato Pests
- Tomato is affected by several major insect pests causing significant yield loss.
- Pests attack various plant parts: leaves, stems, flowers, and fruits.
- Effective management requires knowledge of pest biology and damage symptoms.
- Integrated pest management (IPM) combines cultural, biological, and chemical methods.
Tomato Fruit Borer (Helicoverpa armigera)
Scientific Name: Helicoverpa armigera
Family: Noctuidae
Order: Lepidoptera
Distribution: Tropics, subtropics, and warmer temperate regions.
Identification:
- Caterpillars: Varying color, radiating hairs, brown to greenish with dark lines.
- Moth: Medium-sized, light yellowish brown, forewings with dark spot, hindwings pale with black border.
Tomato Fruit Borer – Biology and Damage
Life Cycle:
- Eggs laid on tender plant parts.
- Larval period: 18–25 days; pupates in soil.
- Complete life cycle: ~30–40 days.
Nature of Damage:
- Young larvae feed on foliage; older larvae bore into fruits.
- Bores circular holes, feeds on fruit contents.
- Damaged fruits often invaded by secondary pathogens.
- One larva can damage 2–8 fruits.
Tomato Fruit Borer – Management
Cultural and Mechanical Control:
- Collect and destroy infested fruits and larvae.
- Deep ploughing after harvest to expose pupae.
- Intercrop with marigold (1:16 rows) to attract egg-laying adults.
Biological Control:
- Release Trichogramma pretiosum or T. chilonis (egg parasitoids).
- Release Chrysoperla carnea (predator) at 30 days after planting.
- Spray Bacillus thuringiensis or Helicoverpa NPV.
Chemical Control:
- Use pheromone traps (Helilure) at 12/ha.
- Spray recommended insecticides: Azadirachtin, Indoxacarb, Flubendiamide, Novaluron, Phosalone, Quinalphos (as per label rates).
- Grow resistant varieties: Rupali, Roma, Pusa Red Plume.
Serpentine Leaf Miner (Liriomyza trifolii)
Scientific Name: Liriomyza trifolii
Family: Agromyzidae
Order: Diptera
Identification:
- Larva: Minute, orange-yellow, apodous maggots.
- Adult: Small, pale yellow flies.
Life Cycle:
- Eggs laid singly on leaf surface.
- Larval period: 7–10 days; pupates in soil or leaves.
- Total life cycle: ~3 weeks.
Serpentine Leaf Miner – Damage and Management
Nature of Damage:
- Larvae mine between leaf epidermal layers, creating serpentine tunnels.
- Severe infestation causes leaf drying and drop.
Management:
- Collect and destroy mined leaves.
- Spray neem seed kernel extract (NSKE) 5%.
- Use yellow sticky traps for monitoring.
Whitefly (Bemisia tabaci)
Scientific Name: Bemisia tabaci
Family: Aleyrodidae
Order: Hemiptera
Identification:
- Eggs: Pear-shaped, light yellow.
- Nymphs: Oval, scale-like, greenish-white.
- Adults: Tiny, white, scale-like.
Whitefly – Damage and Management
Nature of Damage:
- Nymphs and adults suck sap, causing chlorosis and leaf curling.
- Vector of tomato leaf curl virus.
Management:
- Uproot and destroy infected plants.
- Remove alternate weed hosts (e.g., Abutilon indicum).
- Use yellow sticky traps (12/ha).
- Apply carbofuran 3G or recommended insecticides: Dimethoate, Malathion, Oxydemeton-methyl, Thiamethoxam.
Aphids (Aphis gossypii, Myzus persicae)
Scientific Names: Aphis gossypii, Myzus persicae
Family: Aphididae
Order: Hemiptera
Nature of Damage:
- Nymphs and adults suck sap from leaves and shoots.
- Plants turn yellow, become deformed, and may dry up.
- Honeydew secretion leads to sooty mould, reducing photosynthesis.
Aphids – Management
- Seed treatment with imidacloprid or thiamethoxam.
- Use yellow sticky traps for monitoring and control.
- Spray recommended systemic insecticides if needed.
Thrips (Thrips tabaci)
Scientific Name: Thrips tabaci
Family: Thripidae
Order: Thysanoptera
Identification:
- Nymphs: Yellowish.
- Adults: Dark, slender, fringed wings.
Nature of Damage:
- Silvery streaks on leaves, bud necrosis, premature flower drop.
- Vector of tomato spotted wilt virus.
Thrips – Management
- Uproot and destroy diseased plants.
- Use yellow sticky traps (15/ha).
- Release Chrysoperla carnea larvae (10,000/ha).
- Spray methyl demeton or dimethoate as per recommendations.
Red Spider Mite (Tetranychus spp.)
Scientific Name: Tetranychus spp.
Family: Tetranychidae
Order: Acarina
Identification:
- Eggs: Hyaline, globular, laid in masses.
- Nymphs: Yellowish.
- Adults: Small, red.
Nature of Damage:
- Leaves turn reddish-brown, bronzed, and dry.
- Webbing on leaves; severe infestation affects flowering and fruiting.
Red Spider Mite – Management
- Spray wettable sulphur 50 WP (2 g/litre).
- Spray dicofol 18.5 EC (2.5 ml/litre) if needed.
- Maintain field sanitation and avoid dust accumulation.
Summary: Integrated Pest Management in Tomato
- Monitor pest populations regularly using traps and field scouting.
- Adopt resistant varieties and crop rotation.
- Promote natural enemies and use biopesticides.
- Apply chemical pesticides judiciously, following recommended doses and intervals.
- Combine cultural, biological, and chemical methods for sustainable pest management.
Objective Questions
Q1. Which family does Helicoverpa armigera belong to?
A. Noctuidae
B. Gelechidae
C. Agromyzidae
D. Aleurodidae
Answer: A
Q2. What is the recommended ratio of American tall marigold to tomato rows for managing tomato fruit borer?
A. 1:10
B. 1:16
C. 1:20
D. 1:25
Answer: B
Q3. Which insecticide is recommended at a dose of 8 ml/10 lit for tomato fruit borer control?
A. Flubendiamide
B. Indoxacarb
C. Novaluron
D. Phosalone
Answer: B
Q4. Which pest is introduced into India through chrysanthemum cuttings?
A. Tuta absoluta
B. Liriomyza trifolii
C. Bemisia tabaci
D. Aphis gossypii
Answer: B
Q5. Which order does the whitefly, Bemisia tabaci, belong to?
A. Lepidoptera
B. Diptera
C. Hemiptera
D. Thysonoptera
Answer: C
Q6. Which pest is a vector of tomato spotted wilt virus?
A. Aphids
B. Thrips tabaci
C. Red spider mite
D. Tuta absoluta
Answer: B
Q7. What is the recommended dose of wettable sulphur for red spider mite control?
A. 2g/lit
B. 5g/lit
C. 8g/lit
D. 10g/lit
Answer: A
Q8. Which pest's larvae are described as minute orange yellowish apodous maggots?
A. Helicoverpa armigera
B. Thrips tabaci
C. Liriomyza trifolii
D. Tetranychus spp
Answer: C
Q9. Which chemical is recommended for seed treatment against aphids?
A. Imidachloprid
B. Dimethoate
C. Dicofol
D. Azadirachtin
Answer: A
Q10. Which pest's adult is described as red colored and small sized?
A. Bemisia tabaci
B. Thrips tabaci
C. Tetranychus spp
D. Liriomyza trifolii
Answer: C