Climate-based guidance for tobacco thrips (Frankliniella fusca) and tomato spotted wilt virus in North Carolina

Tobacco thrips, Frankliniella fusca, are vectors of tomato spotted wilt virus (TSWV) which causes heavy tobacco crop losses in North Carolina. A risk based decision guide was created to assess the need for NC tobacco growers to implement specific TSWV management practices. Tobacco thrips are most dangerous during their third generation flight and tobacco plants are most susceptible to TSWV in the first few weeks following transplant into the field. Being able to predict when the third generation flight will occur and its relation to a grower's anticipated transplant date can aid growers in deciding when to transplant and what treatment practices to use when transplanting, protecting their crops and reducing over-use of pesticides. The decision guide is web-based and asks users for their location, the types of greenhouse insecticides they use, their anticipated planting date, and the historic TSWV incidence for their field or area. Past weather data, climate data, and forecasted temperatures and precipitation amounts are used to determine the thrips flight dates and relative numbers of dispersing thrips. These are contextualized by also showing these values for the previous year, a year with a low incidence of TSWV (2003), and a year with a high incidence of TSWV (2002). The decision guide has been introduced to a small group of tobacco growers and county extension agents for testing and the guide has received positive feedback. In the future this will be introduced to a wider audience of tobacco growers across North Carolina.