The Thripidae (Thysanoptera) of Sweden with special focus on wetland thrips fauna

Thrips (Thysanoptera) are a species-rich order of very small insects, of which only a small proportion are agricultural and horticultural pests. The majority live a hidden life in flowers, leaves, ferns or dead wood and have important ecological functions as pollinators, herbivores, fungivores and decomposers. The family Thripidae is the most diverse thrips family globally and Nordic knowledge has long been characterised by older collections and fragmentary faunistic work. This project aimed to fill central knowledge gaps through a coherent approach: targeted inventory in both traditional and understudied environments (especially wetlands), review of museum and private collections, morphological revision and development of modern identification tools, as well as DNA barcoding as support for species delimitation and future identification.

The work resulted in a comprehensive checklist for Swedish Thripidae and a detailed morphological identification key adapted to Swedish fauna. Material was collected in 2020–2025 using several complementary methods (sweeping, beating, traps and targeted collection on host plants), and was supplemented with historical material from the Swedish Museum of Natural History and Lund University's Zoological Museum, as well as donations from colleagues and the public. For most of the material, non-destructive DNA extraction and COI barcoding were used; a total of 567 COI sequences representing 49 species were generated and made available via BOLD and GenBank. Species-specific question marks were also tested using molecular species delimitation methods; the results support that Chirothrips ambulans and Thrips menyanthidis should be considered valid species, which is important for both identification and interpretation of distribution and habitat requirements.

Faunistically, ten species are reported as new to Sweden and 98 new landscape finds, with particularly many new records from northern Sweden – a pattern that primarily reflects historical undersampling. By compiling host plant associations and habitat annotations, including a special review of wetlandassociated species, it is made clear that wetlands (marshes, rich fens, coastal meadows, reed belts and brackish water-influenced coastal environments) are home to a hitherto underestimated part of Swedish thrips diversity. The project's results – updated species lists, revised taxonomy, images and interactive identification keys – provide practical tools for research, environmental monitoring and conservation decisions, and strengthen the building of expertise within Swedish insect taxonomy.

Text: Emma Wahlberg

To read the full summary, please go to the Swedish version of this page.