Host plant resistance in Japanese chrysanthemums against Frankliniella occidentalis (Thysanoptera: Thripidae) during the non-flowering stage

Abstract

Leaf damage caused by Frankliniella occidentalis and its population growth were investigated with the vegetative plants of two Japanese chrysanthemum cultivars, Yuki-no-izumi and Kan-komichi in greenhouses. Significant differences were found in the levels of leaf damage and thrips population growth between the two cultivars. On Kan-komichi, which had significantly less damage to leaves, the size of the thrips population was smaller than that on Yuki-no-izumi, indicating a clear difference in host plant resistance to F. occidentalis between the two cultivars. Life history characters of the thrips were individually determined on the two cultivars in a laboratory. Most thrips larvae that fed on the leaves of Kan-komichi died before prepupation. This high mortality can contribute to a higher resistance demonstrated by that cultivar in the greenhouse experiment.