Viral Severity: CRITICAL ⚠️ Contagious

Tomato Spotted Wilt Virus (TSWV): How to Identify & Treat Fast

Tomato Spotted Wilt Virus (TSWV) is one of the most devastating viral diseases affecting over 1,000 plant species across 85 families. It is transmitted by thrips and cannot be cured once a plant is infected. The virus causes severe stunting, bronzing of leaves, necrotic spots, and significant yield losses. Early detection and removal of infected plants is critical to prevent spread.

Spread speed

Fast

Recovery time

90 days

🔍 Symptoms

Main Symptoms

! Bronze appearance on upper leaves
! Small brown necrotic spots and lesions
! Chlorotic yellow ring spots on foliage
! Wilting or drooping despite adequate water
! Severe stunting and reduced plant growth
! Yellow ringspots and brown necrotic sunken areas on fruit
! Shepherd's crook appearance in young seedlings (leading to death)
! Concentric rings and spot patterns on leaves and fruit
! Cupping and curling of leaves
! Death of leaf petioles and growing tips
! Line patterns and spots on flower petals

Visual Signs

Bronze appearance on leavesSmall brown necrotic spots on foliageChlorotic ring spotsWilting or drooping of infected plantsStunting and reduced growthYellow ringspots on fruitBrown necrotic sunken areas on fruitShepherd's crook appearance in infected seedlingsConcentric rings and spots on leavesCupping of leavesDeath of petioles and growing tips

Affected parts: LEAVESStemFruitsWhole plant

❓ Possible Causes

→ Transmission by thrips (at least 10 species) during larval feeding
→ Thrips acquire virus only during larval stage by feeding on infected plants
→ Infected thrips transmit virus throughout their lifetime
→ Virus reservoirs in weeds and alternate host plants
→ Movement of infected transplants
→ Spread accelerated by high thrips populations

💊 Treatment

⚡

Quick Fixes

~45 days

Step 1

Immediately remove and destroy all plants showing symptoms

Step 2

Apply systemic insecticide (imidacloprid) as soil drench to remaining plants

Step 3

Spray foliar insecticide (spinetoram or abamectin) targeting thrips

Step 4

Install physical barriers: fine mesh screens if in greenhouse

Step 5

Double scouting frequency to daily inspections for 2 weeks

Step 6

Remove all weeds and potential virus reservoirs within 50 feet

Step 7

Mark affected area and avoid planting susceptible crops for 60 days

Materials needed:

Thrips insecticidePruning shearsDisposal bagsFoliar fertilizer

🌿

Organic Treatment

~90 days

Step 1

Scout plants daily and immediately remove any showing bronze leaves or ring spots

Step 2

Destroy removed plants by burning or sealed plastic bags (never compost)

Step 3

Apply neem oil spray (0.5-1%) weekly to suppress thrips populations

Step 4

Install yellow sticky traps every 10 feet to monitor and trap thrips

Step 5

Introduce beneficial predatory mites (Amblyseius cucumeris) weekly for 4 weeks

Step 6

Apply diatomaceous earth around plant bases and refresh after rain

Step 7

Eliminate all weeds within 100 feet of planting area

Step 8

Remove old crop debris and volunteer plants immediately

Step 9

Apply reflective mulch or aluminum foil strips to repel thrips

Materials needed:

Blue sticky trapsNeem oilReflective mulchGarlic extractTrap crops

🔬

Expert Treatment

~135 days

Step 1

Conduct immediate field survey and map all infected plants with GPS/markers

Step 2

Establish 3-zone management: hot zone (infected), buffer zone (high-risk), safe zone

Step 3

Remove and destroy all infected plants in hot zone plus 5-foot buffer

Step 4

Implement dual-mode insecticide program: systemic (imidacloprid soil drench) + foliar rotation (spinetoram week 1, abamectin week 2, repeat)

Step 5

Deploy intensive thrips monitoring: yellow sticky traps every 8-10 feet, count weekly

Step 6

Release biological control agents: predatory mites (Amblyseius) and minute pirate bugs biweekly

Step 7

Execute radical weed suppression protocol within 200 feet using mulch and targeted herbicides

Step 8

Install UV-reflective mulch in buffer and safe zones

Step 9

Conduct molecular testing (ELISA or PCR) on asymptomatic high-risk plants in buffer zone

Step 10

Implement post-harvest sanitation: remove all plant material, deep till, 60-day fallow period

Step 11

Replant only with resistant varieties (Sw-5 tomatoes or Tsw peppers)

Step 12

Establish preventive thrips management for next crop: pre-transplant imidacloprid, weekly scouting, trap monitoring

Step by Step

1
Immediately isolate and remove all symptomatic plants
2
Destroy infected plants by burning or sealed disposal (never compost)
3
Apply thrips control measures to remaining healthy plants
4
Increase scouting frequency to twice weekly
5
Intensify weed management within 100 feet of affected area
6
Consider replanting with resistant varieties if losses exceed 30%

🧪 Solutions

🌱 Natural Solutions

✓ Remove and destroy infected plants immediately (do not compost)
✓ Apply neem oil spray to reduce thrips populations
✓ Use insecticidal soap targeting thrips adults and larvae
✓ Introduce beneficial insects like predatory mites (Amblyseius species) and minute pirate bugs
✓ Apply diatomaceous earth around plant bases
✓ Use garlic or hot pepper spray as thrips repellent
✓ Maintain high biodiversity to support natural predators
✓ Spray spinosad (organic insecticide) for thrips control

💉 Chemical Solutions

✓ Apply systemic insecticides like imidacloprid for thrips control (pre-transplant soil drench)
✓ Use foliar insecticides: spinetoram, abamectin, or acephate
✓ Treat with neonicotinoids for seedling protection
✓ Apply contact insecticides targeting adult thrips
✓ Note: No chemical can cure the virus; focus is on vector control

🛡️ Prevention

✓ Use certified virus-free and thrips-free transplants from reputable sources
✓ Implement strict weed management in and around planting areas
✓ Avoid planting near older fields or known TSWV-infected areas
✓ Use resistant varieties with Sw-5 gene (tomatoes) or Tsw gene (peppers)
✓ Apply UV-reflective mulch to repel thrips
✓ Install yellow sticky traps to monitor and reduce thrips populations
✓ Practice crop rotation with non-host plants
✓ Remove crop debris and volunteer plants immediately after harvest
✓ Establish physical barriers like fine mesh screens in greenhouses
✓ Inspect plants weekly for early symptoms and remove infected plants immediately

🌿 Common in These Plants

Amaryllis

African Milk Tree

Moon Orchid

Sky Plant