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. 

Predictive models for the locations below continue to suggest elevated TSWV risk for the 2026 tobacco season, especially in the Kinston and Whiteville areas. The estimated end-of-season TSWV risk was 61.9% for Kinston and 49.2% for Whiteville, while the estimated risk was lower but still higher than historical averages at 13.4% for Kenly and 13.3% for New Bern.

Based on our scouting efforts over the last few weeks, we observed a steady increase in TSWV incidence on commercial farms and research trials (Table 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. 

Table 1. 2026 TSWV incidence in four commercial tobacco fields and two research fields (at Kinston and Rocky Mount) monitored weekly in NC. TSW-diseased and dead plants due to TSWV were counted together.

At this point in the season, the 3rd generation thrips flight has already occurred at all four example locations. The 4th generation was estimated around April 25 in Whiteville, May 9 in Kinston, May 13 in New Bern, and May 14 in Kenly. The 4th generation has completely dispersed in the Whiteville and Kinston areas, while more than 50% of the flight is ongoing in Kenly and New Bern areas. This is important because tobacco plants are most susceptible to TSWV during the first six weeks after transplanting, and the infection risk period overlapped with the early post-transplant window for an April 15 planting date in the predicted high-risk areas of Kinston and Whiteville. Therefore, fields transplanted in mid-April likely overlapped with one or both of the 3rd and 4th generations, particularly in Kinston and Whiteville, where estimated risk remains high. Earlier thrips flights lead to early seedling infections and rapid seedling death, which we are seeing in various fields during our monitoring efforts.

Because TSWV symptoms can take 2–4 weeks after infection to become visible, the infections and plant death we are seeing this week are likely the result of infections from 1-3 weeks ago. Also, lack of symptoms immediately after thrips flights does not necessarily mean that infection did not occur.

Fields transplanted in mid- to late April may be at greater risk this year in areas like Kenly and Kinston, compared to previous years when there was a few days' gap between early planting (April 10-15) and 3rd generation flights. Because TSWV symptoms may take 2–4 weeks after infection to become visible, the absence of symptoms immediately after thrips flights does not necessarily indicate that infection has not occurred.

It is likely that areas with a high incidence of TSWV in 2025 will experience high disease incidence this year. Tobacco growers in these areas may want to consider foliar applications 2–3 weeks after transplant to protect their crop. Well-timed applications in high-risk areas (>10% risk areas) are vital to protect the crop. Treatment in addition to standard insecticides is typically not required for low-risk areas with a history of <10% TSWV incidence. However, if TSWV incidence reached 10% or higher in any of these low-risk areas in 2025, additional applications may need to be considered in 2026 to protect the crop, even if planted early (around April 15).

A greenhouse or transplant water application of imidacloprid, alone or combined with Actigard® foliar applications, is recommended to minimize potential losses from TSW disease if you have yet to plant your tobacco. If imidacloprid was not applied in the greenhouse or at transplant, foliar applications of imidacloprid can be conducted to protect against TSWV. More than one application of imidacloprid products within a season is not recommended due to insecticide resistance concerns. If foliar applications of Actigard® are being considered, the sooner plants are treated, the better, since it takes a few days for the product to become effective, and it can provide protection for ~2 weeks (depending on environmental conditions). Once the 4th generation of thrips has dispersed completely, additional insecticide applications are not recommended, as most of the TSW infections have already occurred.

For any late-planted fields or fields still within the early susceptible window, risk remains greatest where small plants overlapped with current 4th generation flights.

See the NC Agricultural Chemicals Manual and the NC Flue Cured and Burley Tobacco Guide for details on TSWV management practices.

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.