We want to inform you that the Tobacco Thrips Flight and TSWV Intensity Predictor tool is currently experiencing technical issues. We apologize for any inconvenience this may cause. At this time, we recommend that growers do not use the tool until further notice. We will provide an update as soon as the tool is fully functional again. Thank you for your understanding and patience.

Additionally, please note that the predictive models published last week are incorrect due to these technical issues and should be disregarded. For the time being, the tobacco thrips estimated dispersal can be calculated using the Thrips Infestation Predictor for Cotton. Beware that the Thrips Infestation Predictor for Cotton is fully functional at the moment and the information regarding thrips dispersal is accurate, but unlike the Tobacco Thrips and TSWV Predictor tool, it will only provide a reference of thrips dispersal and Degree Day Accumulation graphs useful for tobacco growers, as shown below. It will NOT provide suggestions on when or what to apply, estimated TSWV risk, or comparisons of TSWV incidence during the last years. 

Using the prediction tool for cotton, models were created for:

• Kenly is a relatively low TSWV risk site (typically less than 8%), situated within large acreage production areas in Johnston and Wilson Counties.
• Kinston is a moderate TSWV risk site (typically less than 10%) 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 8% or above 10%) in Columbus County and also houses the NCDA & CS Border Belt Tobacco Research Station where tobacco research is conducted.

Based on these models, currently, only thrips populations from the 2nd generation are dispersing. The third generation of tobacco thrips is the one that typically transmits the most TSWV. The 3rd generation is estimated to begin dispersing as late as May 17 for Kenly (Fig. 1), May 10-11 for Kinston and New Bern, and as early as May 5 for Whiteville (Fig 2). The 4th generation usually begin dispersing 2 to 2.5 weeks after the 3rd generations began to disperse.

If tobacco was treated with imidacloprid or a mix of imidacloprid and Actigard® in the greenhouse or at transplant, they should be protected against thripsfor an average period of 21-27 days (depending on environmental conditions).If foliar applications of Actigard® are being considered post-transplant, to protect the plants after that period, beware that it can take 10-14 days for Actigard® to be effective, so plan accordingly.See the NC Agricultural chemicals Manual and the NC Flue Cured and Burley Tobacco Guide for details on TSWV management practices.

Historically, 3rd generation thrips flights were reported in the second week of May in most tobacco production areas in NC. This year thrips began to disperse earlier (~1 week earlier in some areas east of the state) and this trend may continue to be the case in upcoming years. This means the populations are maturing faster than expected due to multiple factors (climatic conditions such as less rain in the winter and early spring, more winter weed survival, warmer springs, among others). We need to accommodate to these populations changes and start scouting and using the prediction tool earlier every year to protect tobacco transplants. Additionally, tobacco transplants in the field can have fewer risk of TSWV infection if planted in mid-April or early April (assuming no late freezes are forecasted).

More Information

NC Agricultural chemicals Manual

NC Flue Cured and Burley Tobacco Guide

Thrips Infestation Predictor for Cotton

Insect - Tobacco Thrips

Scouting for Tobacco Thrips and Tomato Spotted Wilt Virus