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. The TSWV Predictor was recently undergoing model validation and will be publicly available soon. Thank you for your patience!

Weather conditions were notably colder and drier than normal this past winter and early spring. From December 2025 through February 2026, average temperatures were roughly 5°F below the 1991–2020 historical average of 47.5°F, and total precipitation was 7.50 inches, well short of the typical 10.23 inches for the same period. Early spring (March 1–April 23, 2026) brought a reversal in temperatures, with a mean of 61.8°F running about 4°F above normal, but rainfall remained scarce at only 1.86 inches compared to an expected 6.55 inches for that period. This combination of a cold, dry winter followed by a warm, dry early spring may have influenced thrips development and indicates a higher TSWV risk forecast for the 2026 season.

Predictive models for the locations below showed higher estimated TSWV risk in 2026 than in 2025. Kenly and New Bern had a similar estimated risk of 13.4% and 13.2%, respectively. These locations showed an increase in risk estimates, from historical averages of 5% and 8%. In contrast, prediction models estimated substantially higher risk for Kinston (62.2%) and Whiteville (49.1%). The most pronounced increase was at Kinston, where the estimated risk increased from approximately 11% in 2025 to 62.2% in 2026, followed by Whiteville, where the 2026 estimate reached 49.1% from a historical average of 10-15%.

The timing of the 3rd and 4th tobacco thrips generations is especially important because these flights occur near the tobacco transplant period and are the most relevant for early-season TSWV transmission. The 3rd generation was expected to begin around April 7 in Whiteville, April 17 in Kinston, April 19 in New Bern, and April 20 in Kenly. Most tobacco areas are already seeing some thrips numbers in the field. Our research plots located in Rocky Mount showed an average of 0.2 thrips per plant, while our research plot in Kinston showed 0.52 thrips per plant. No TSW symptoms have been observed in either field yet. Be aware that it takes approximately 2-4 weeks from infection with TSWV to symptom appearance. The 4th generation was predicted to begin around April 26 in Whiteville, May 8 in Kinston, May 11 in New Bern, and May 12 in Kenly.

Last year, the predictive models estimated that the 3rd and 4th tobacco thrips generations would occur during the last week of April or the first week of May. In 2026, however, the warm early-spring conditions may have accelerated tobacco thrips development, resulting in earlier predicted flight activity. These 3rd and 4th generation flights are especially important because they typically contribute the most to TSWV transmission. Under normal timing, seedlings transplanted in late April are often at greater risk than those transplanted before mid-April; however, with earlier thrips flights predicted this year, risk is elevated whenever the 3rd and 4th generation flights overlap with recently transplanted, small tobacco plants that are still highly susceptible to infection.

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. This year, early-season monitoring for TSWV and 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, especially fields planted in late April.

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). 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.

Weather conditions were analyzed and discussed based on data from the NC State Climate Office.