Economic injury level for sequential sampling plan of Frankliniella schultzei in bell pepper crops

Abstract

Sampling plans and economic injury level are essential parts of integrated pest management programs. The economic injury level is the pest control threshold most widely used whereas sequential sampling plans enable fast decision-making. The common blossom thrips, Frankliniella schultzei, is an important worldwide pest in bell pepper crops. However, a decision-making system has not yet been determined for this pest in this crop. Here, we determined an economic injury level and a sequential sampling plan for F. schultzei in bell pepper crops. The cost of control of F. schultzei was 2% of the production value, while this pest caused losses up to 49%. The yield curve of the crops according to F. schultzei attacks indicated that the bell pepper tolerated low pest densities (up to 1 thrips per sample unit), and this pest caused mainly the direct damage to bell pepper plants by sucking cellular contents and injecting toxins. The economic injury level determined was of 1 thrips per sample. In the sequential sampling plan, up to 44 sample units per field were evaluated. In addition, this sequential sampling plan resulted in a correct decision in 100% of the situations saving 70% of the time. Therefore, the decision-making system proposed by this study can be incorporated into bell pepper integrated pest management programs because provides an option of optimizing and reducing the pest sampling effort in this crop.