Population performance and detoxifying and protective enzyme activities of four thrips species feeding on flowers ofMagnolia grandiflora(Ranunculales: Magnolia)

Abstract

AbstractBACKGROUNDDifferent thrips species can co‐occur on the same flowers with different dominance degrees. To accurately evaluate the population performance on different thrips species onMagnolia grandifloraflowers, we investigated the diversity of thrips species and their population dynamics both in the field and laboratory. In addition, the activities of detoxifying and protective enzymes in thrips were also measured.RESULTSField investigations revealed that four thrips species (Thrips hawaiiensis,Thrips flavidulus,Frankliniella occidentalis, andThrips coloratus) coexisted onM. grandifloraflowers. They were ranked, from highest population density to lowest, as follows:T. hawaiiensis > T. flavidulus > F. occidentalis > T. coloratus. In laboratory investigations, the species were ranked, from fastest developmental rates to slowest, as follows:F. occidentalis > T. hawaiiensis > T. flavidulus > T. coloratus; and from largest population size to smallest, as follows:T. hawaiiensis > F. occidentalis > T. flavidulus > T. coloratus. Biochemistry assays showed that the four species differed in their activities of detoxifying enzymes (carboxylesterase, glutathione‐S‐transferase, and cytochrome P450) and protective enzymes (superoxide dismutase, peroxidase) in both laboratory and field strains.CONCLUSIONDifferences in population performance among these four thrips onM. grandifloramay be related to their activity levels of physiological enzymes. The variations in thrips population performance between the field and the laboratory could be due to differences in environmental conditions.T. hawaiiensisshowed a strong host preference forM. grandiflora, and thus it has the potential to be a dangerous pest in horticultural plants. © 2023 Society of Chemical Industry.