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, including biological, cultural, and chemical control methods. Understanding these pests is essential for sustainable tomato production and minimizing crop losses. Key academic terms include Helicoverpa armigera, Tuta absoluta, integrated pest management, vector, and biological control.
Introduction to Tomato Pests
- Tomato is affected by several major insect pests worldwide.
- Pests cause direct damage and act as vectors for viral diseases.
- Effective management is crucial for yield and quality.
Tomato Fruit Borer (Helicoverpa armigera)
Scientific Name: Helicoverpa armigera
Family: Noctuidae
Order: Lepidoptera
Distribution: Tropics, subtropics, and warmer temperate regions
Economic Importance:
- Major pest of tomato and other crops (e.g., pigeon pea, chickpea).
Tomato Fruit Borer – Identification and Life Cycle
Identification:
- Caterpillar: Varies in color, radiating hairs, brown to greenish with dark lines.
- Moth: Medium-sized, light yellowish-brown, forewings with dark spot, hindwings pale with black border.
Life Cycle:
- Eggs laid on tender plant parts.
- Larval stage: 18–25 days.
- Pupates in soil.
- Total life cycle: 30–40 days.
Tomato Fruit Borer – Nature of Damage
- Young larvae feed on foliage; older larvae bore into fruits.
- Creates circular holes in fruits, feeds on inner contents.
- Damaged fruits often infected by secondary pathogens.
- One larva can destroy 2–8 fruits.
Tomato Fruit Borer – Management
Cultural Control:
- Collect and destroy infested fruits and larvae.
- Deep ploughing after harvest to expose pupae.
- Intercrop tomato with marigold (1:16 rows).
Biological Control:
- Release Trichogramma spp. and Chrysoperla carnea.
- Spray Bacillus thuringiensis (2g/lit).
- Use Helicoverpa NPV (HaNPV) @ 250 LE/ha.
Chemical Control:
- Use pheromone traps (Helilure) @ 12/ha.
- Spray recommended insecticides: Azadirachtin, Indoxacarb, Flubendiamide, Novaluron, Phosalone, Quinalphos.
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 upper 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 trails.
- Severe infestation causes leaf drying and drop.
Management:
- Collect and destroy mined leaves.
- Spray neem seed kernel extract (NSKE) 5%.
Tomato Leaf Miner (Tuta absoluta)
Scientific Name: Tuta absoluta
Family: Gelechiidae
Order: Lepidoptera
Nature of Damage:
- Larvae mine leaves, stems, and fruits.
- Causes leaf necrosis, fruit damage, and yield loss.
Management:
- Use pheromone traps, biological control agents, and selective insecticides.
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 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, causing yellowing and deformation.
- Honeydew secretion leads to sooty mould, reducing photosynthesis.
Management:
- Seed treatment with imidacloprid or thiamethoxam.
- Use yellow sticky traps.
Thrips (Thrips tabaci)
Scientific Name: Thrips tabaci
Family: Thripidae
Order: Thysanoptera
Identification:
- Nymphs: Yellowish.
- Adults: Dark, fringed wings.
Nature of Damage:
- Silvery streaks on leaves, bud necrosis, 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 25 EC or dimethoate 30 EC @ 1 L/ha.
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; reduced flower and fruit formation.
Red Spider Mite – Management
- Spray wettable sulphur 50 WP @ 2g/lit.
- Spray dicofol 18.5 EC @ 2.5 ml/lit.
Summary: Integrated Pest Management in Tomato
- Combine cultural, biological, and chemical methods for effective pest control.
- Monitor pest populations regularly.
- Use resistant varieties and crop rotation.
- Minimize pesticide use to prevent resistance and protect beneficial organisms.
Objective Questions
Q1. Which family does the tomato fruit borer, 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 seedlings 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 20 WG
B. Indoxacarb 14.5% SC
C. Novaluron 10% EC
D. Quinalphos 25% EC
Answer: B
Q4. Which pest is a vector of tomato leaf curl disease?
A. Thrips tabaci
B. Bemisia tabaci
C. Aphis gossypii
D. Tuta absoluta
Answer: B
Q5. What is the order of the serpentine leaf miner, Liriomyza trifolii?
A. Lepidoptera
B. Hemiptera
C. Diptera
D. Thysonoptera
Answer: C
Q6. Which biological control agent is released at 1 lakh/ha for tomato fruit borer management?
A. Trichogramma chilonis
B. Trichogramma pretiosum
C. Chrysoperla carnea
D. Bacillus thuringiensis
Answer: B
Q7. Which chemical is applied at 2g/lit for red spider mite management?
A. Dicofol 18.5 EC
B. Wettable sulphur 50 WP
C. Carbofuran 3% G
D. NSKE 5%
Answer: B
Q8. Which pest causes silvery streaks on tomato leaves and is a vector of tomato spotted wilt virus?
A. Aphis gossypii
B. Thrips tabaci
C. Tetranychus spp
D. Liriomyza trifolii
Answer: B
Q9. Which of the following is NOT a recommended insecticide for whitefly control on tomato?
A. Dimethoate 30% EC
B. Malathion 50% EC
C. Thiamethoxam 25% WG
D. Flubendiamide 20 WG
Answer: D
Q10. What is the color of the adult red spider mite?
A. Yellow
B. Green
C. Red
D. Brown
Answer: C
