Pest thrips do not set field margins aside: preferred wildflowers sustain pest Frankliniella spp. (Thysanoptera: Thripidae) and their migration in commercial strawberry

Abstract

Wildflowers in uncultivated field margin are important resources supporting both pest and non-pest thrips populations in agroecosystems. Environmental factors related to wildflowers have never been used as predictors to model pest thrips density in adjacent crops. Wild and cultivated flowers were sampled in strawberry field agroecosystem in Orléans Island, near Quebec City, Canada. Pest flower thrips Frankliniella intonsa and F. tritici had a wide wildflower host range, with preferences toward Leucanthemum vulgare, Trifolium pratense, Sonchus asper, and Cichorium intybus. Regression modeling revealed significant positive relationships between pest thrips density on specific wildflowers (Vicia cracca, Sinapis arvensis, S. asper, C. intybus, L. vulgare) and their density in strawberry flowers. Furthermore, thrips density within the crop decreased with distance from uncultivated field margin. Regarding crop management, knowing the associations between thrips pests and preferred wild flora as well as their spatial distribution in strawberry fields is an undeniable advantage.