To help growers determine the potential of management practices for TSWV, we have created step-by-step guides on how to use the Tobacco Thrips Flight and TSWV Intensity Predictor to create Current Year TSWV Risk Assessments and Historical TSWV Predictions. Growers are strongly encouraged to create their own models using the information from their fields and season dates to plan for Tomato Spotted Wilt Virus (TSWV) management. 

This is the final TSWV risk assessment update for the 2026 tobacco season. These updates were intended to help growers evaluate TSWV risk and interpret how tobacco thrips dispersal timing aligns with transplant timing and the early post-transplant period, when tobacco plants are most susceptible to infection. When possible, transplant timing should avoid placing small plants in the field during the 3rd and 4th tobacco thrips flight periods, while also avoiding the risk of freeze injury from planting too early. However, in years with warm early-spring conditions, thrips development may advance more quickly, increasing the risk that early or mid-April transplants will overlap with 3rd and 4th generation flights. Early thrips dispersal in 2026 (even 3-5 days earlier than in previous years) increased the likelihood of TSWV infection in fields where small tobacco plants were present during the 3rd and 4th generation flights. The 2026 season reinforces the importance of using thrips flight predictions before and during the transplant window for upcoming seasons.

At this point in the season, the major tobacco thrips flights associated with most TSWV transmission (3rd and 4th generations) have already passed in all locations used for these reports: The 4th generation was expected to start around April 25 in Whiteville, May 9 in Kinston, May 13 in New Bern, and May 14 in Kenly. Therefore, new infections associated with the 3rd and 4th generation flights have likely already occurred. Symptoms and plant death observed now are likely the result of infections that took place 2-3 weeks earlier, when young plants overlapped with thrips movement.

Based on our scouting efforts over the last few weeks, we observed a steady increase in TSWV incidence on commercial farms and research fields (Figure 1). This aligns with the predictions of the Risk Assessment Tool, which indicated a higher-than-usual incidence and risk, especially in areas like Kinston and Whiteville.  Fortunately, we did not record any incidents close to or above 30% in our monitored locations or Extension reports. This highlights how monitoring efforts, early management, and preparedness can go a long way when high TSWV risk is expected.

At this point of the season, insecticides sprays solely focused on thrips management are not required as most thrips generations have already dispersed and plant growth has advance in most areas. Beyond six weeks after transplant, tobacco plants become less susceptible to infections. Additionally, symptoms observed in June are likely due to infections from a few weeks ago since it takes the plants 2-3 weeks or more to develop symptoms.

This and future updates are created based on reports generated with the Tobacco Thrips Flight and TSWV Intensity Predictor. Predictor settings include no insecticide treatment, desired planting date (April 15 used as standard planting date), and the average historical TSWV incidence for each location, as listed below:

• Kenly is a relatively low TSWV risk site (typically around 5%), situated within large acreage production areas in Johnston and Wilson Counties.
• Kinston is a moderate TSWV risk site (typically around 8%) in Lenoir County and also houses the NCDA&CS Cunningham Research Station, where extensive tobacco research is conducted.
• New Bern is a higher TSWV risk site (typically above 10%) in Craven County.
• Whiteville is a moderate to high TSWV risk site (around or above 10%) in Columbus County and also houses the NCDA & CS Border Belt Tobacco Research Station , where tobacco research is conducted.