SUSCEPTIBILITY OF ECHINACEA TO ONION THRIPS DAMAGE: A CASE STUDY IN VYTAUTAS MAGNUS UNIVERSITY BOTANICAL GARDEN

Abstract

Onion thrips (Thrips tabaci Lind.) are increasingly recognized as economically significant pests of Echinacea species cultivated for ornamental and medicinal purposes. This study assessed the susceptibility of Echinacea accessions maintained at the Vytautas Magnus University Botanical Garden during the 2024-2025 growing seasons. A total of 108 accessions, including wild species and horticultural cultivars, were evaluated under open-field conditions using standardized morphological assessment and damage scoring methods. Results demonstrated substantial inter- and intra-specific variation in susceptibility to T. tabaci. The most resistant accessions across both seasons were Echinacea paradoxa and its derived cultivars, which exhibited ≤20% damage and retained high ornamental quality. In contrast, E. purpurea and many of its hybrids consistently belonged to the highly susceptible group (70-100% damage), showing extensive leaf deformation, discoloration, and reduced aesthetic value. Yearly climatic differences influenced pest intensity: warmer and drier conditions in 2024 coincided with more severe thrips damage, whereas cooler and wetter periods in 2025 corresponded with a larger proportion of resistant responses. Overall, the findings confirm that susceptibility to onion thrips in Echinacea is genotype-dependent and environmentally modulated. Resistant accessions, particularly those with E. paradoxa lineage, represent valuable material for breeding programs aimed at enhancing pest tolerance in ornamental and medicinal cultivation systems.