Best Ways to Identify, Control & Prevent Tomato Spotted Wilt Virus On Tomato Plants

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Quick Answer: How To Identify Tomato Spotted Wilt Virus And Control Them On Tomato Plants?

Tomato spotted wilt virus (TSWV) affects tomato plants and is spread by thrips. It causes brown ring spots on leaves, wilting of plants, and misshapen fruits. There is no cure for virus-infected plants and so, remove them to prevent the spread of the virus. Select healthy, virus-free plants, manage weeds, use silver reflective mulch, and practice good sanitation measures to control and prevent TSWV.

In this guide, I will discuss the identification, control, and prevention of tomato spotted wilt virus affecting tomato plants.

Read further to know more!

What Is Tomato Spotted Wilt Virus And How Does It Harms Tomato Plants?

Tomato spotted wilt virus (TSWV) affects tomato plants and is carried by various species of thrips.

If the plant is infected in the early growing season, the whole plant may wilt from top to bottom.

Tomato fruits also appear deformed and ripen unevenly.

How To Confirm That Tomato Spotted Wilt Virus Is Troubling Your Tomato Plants?

Check the tomato foliage. Young leaves appear bronze with small brown speckles that may later develop into distinct, necrotic spots. There will be numerous spots on the leaves.

The fruits formed will exhibit round, pale concentric blemishes with chlorotic spots and blotches.

The apex leaves tend to droop, making the plant look wilted. Also, the plants appear stunted and perform poorly.

Click here for the symptoms of TSWV:

Natural Ways To Control Tomato Spotted Wilt Virus On Tomato Plants

The integrative pest management strategy, including monitoring of TSWV symptoms and thrips, following excessive sanitation, and thrips management by releasing biological predators, may help in controlling and managing TSWV on tomato plants.

Method 1- Release Thrips Predator

Biological control can control the thrip population affecting tomato plants and prevent the spread of TSWV.

The beneficial predators include mites (Stratiolaelaps scimitus), predatory rove beetles (Dalotia coriaria), and entomopathogenic nematodes.

  • Spray neem oil– Neem oil spray can be used for controlling thrips followed by introducing beneficial predators.
  • Introduce beneficial predators– Purchase beneficial predators and release them near tomato plants following the manufacturer’s instructions. It will attack at the soil-dwelling stage of thrips.

Click this video on the biological control of thrips:

Physical Ways To Control Tomato Spotted Wilt Virus On Tomato Plants

The TSWV-infected tomato plants have to be removed and destroyed at the early infection stage to prevent the spread of infection. You may use silver reflective mulches to repel thrips from spreading the viral infection.

Method 1- Use Silver Reflective Mulch

Silver reflective mulches are used to repel invading thrips, reducing their numbers on tomato plants and thereby preventing TSWV.

It has to be removed when temperatures are high to avoid the burning of plants.

  • Purchase silver reflective mulch– Silver reflective mulch is available in the garden supply stores. You may also make it by spray painting black plastic sheets with silver paint.
  • Cover with reflective mulch– Remove the weeds and cover the beds with silver reflective mulch to reflect the thrips away.

Here is an informative video on using silver reflective mulches:

Chemical Ways To Control Tomato Spotted Wilt Virus On Tomato Plants

Controlling TSWV is difficult with insecticides. But, the thrips can be controlled with insecticides, including pyrethroids, carbamates, chlorinated hydrocarbons, organophosphates, and soaps.

Rotating the insecticides is the best approach to control thrips as it may build up resistance quickly.

Also, contacting the local county for insecticide approved for home use is preferable.

How To Prevent Tomato Spotted Wilt Virus In Tomato Plants?

TSWV can not be eliminated, but the incidence and severity can be prevented by using cultural practices, including planting virus-free crops, removing infected plants, controlling weeds, and practicing suitable sanitation measures.

Method 1- Remove The Infected Plants

Infected plants can’t be cured and may harbor the virus. Remove the infected parts immediately to prevent further infection.

Method 2- Plant Resistant Varieties

Many TSWV-resistant tomato varieties, including Crista, Plum Regal, Fletcher, Picus, and Bells Rosa can be grown to prevent the incidence of infection. Inspect the plant materials for TSWV symptoms and thrips infestation.

Method 3- Practice Sanitation Measures

Practice good hygienic techniques to prevent the spread of infection. Disinfect tools before and after each use.

Method 4- Manage Weeds

Manage weeds within and around the space as it can be infected by TSWV and become a source of the virus. Also, remove them both inside and outside the greenhouse settings to protect the plants.

Check out this video to prevent TSWV:

What Causes Tomato Spotted Wilt Virus Attacks In Tomato Plants?

TSWV is spread from infected plants to healthy plants by thrips in warm and hot weather with relatively high humidity.

The most critical thrips affecting the plant are western flower thrips, tobacco thrips, and onion thrips.  

It can be transmitted via weeds and winds from surrounding areas. It can also spread via unsanitized garden tools.

Frequently Asked Questions

What is the host of the tomato spotted wilt virus (TSWV)?

TSWV affects a wide range of plants, including tomatoes, peppers, lettuce, onions, spinach, watermelons, and tomatillos. It may also affect a few ornamental plants, including blanket flowers (Gaillardia sp.,), zinnia, and impatiens.

During which life stage do thrips acquire TSWV?

Thrips acquire TSWV during the larval stages after feeding for about 30 minutes on the infected plant. It will transmit the virus to the susceptible plant after 3-18 days. Adult thrips spread the virus and infect the plants.

What time of day are thrips most active?

The adult thrips are most active between 8-10 AM and again between 2-4 PM in greenhouses. Avoid using insecticide spray to control thrips during this active period as they may fly away. You may use sprays before 8, between 10-12 to maximize contact.


Hopefully, this guide has given you specific pointers in controlling and managing TSWV in tomato plants.

Please write me your experiences in controlling this viral infection.

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