Assessing Abundance and Species Composition of Thrips (Thysanoptera) in Florida Lettuce Fields and Optimizing Monitoring Methods

Frankliniella occidentalis is a major threat to lettuce production due to its role in transmitting Impatiens necrotic spot virus (INSV). To better understand the potential risk of INSV outbreaks in Florida lettuce production areas, this study aimed to assess thrips population abundance and species composition. Five methods, whole plant sampling, yellow sticky traps, blue sticky traps, yellow pan traps, and blue pan traps, were evaluated for thrips collection. Traps were placed in one research and two commercial lettuce farms for two growth cycles, Fall 2023 and Spring 2024. Sticky traps collected the highest number of thrips followed by pan traps, and whole plant sampling. Although sticky traps collected the highest number of thrips, specimens were in poor condition and not easily identifiable to species, which is an important step in determining the risk of INSV outbreaks. In contrast, pan traps collected the second highest number of thrips, and preserved specimens well for later identification. Overall, at least eleven species were identified using these sampling methods, the abundant species were Frankliniella bispinosa, Microcephalothrips abdominalis, and Leucothrips piercei. Vectors of orthotospoviruses, F. occidentalis, F. fusca, and F. schultzei, were also detected, underscoring the importance of continued thrips surveillance to safeguard Florida lettuce from thrips and thrips-transmitted viruses.