Diversity of Thrips Species Associated with Soybean Grown in Different Plant Arrangements at Various Phenological Stages

Changes in crop seeding density may affect the presence of phytophagous organisms, whose development is closely associated with host plants. The main objective of this study was to evaluate the abundance and species composition of thrips (Thysanoptera) collected in soybean plants of two different varieties cultivated in different plant arrangements (row spacing, seed density) at different phenological stages. The research was carried out at two locations in southwest Poland between 2015 and 2018. The herbivores that inhabited the plants were caught using an entomological net. The experiments were conducted using a complete block design with four replications. A total of 20 species of thrips were identified and their dietary specialization was determined with an emphasis on the possibility of feeding on Fabaceae plants. Thrips tabaci, Aeolothrips intermedius, and T. fuscipes were the dominant species within the collected material. The general linear model revealed no significant changes in the number of thrips caused by the row spacing, seed density or soybean variety. The significant factor was the phenological stage. The number of thrips increased significantly during the flowering period and shortly after flowering, making them an important threat to the plants. Therefore, it is crucial to develop innovative pest management strategies tailored to effective soybean cultivation to mitigate potential pest-related challenges.