Analysis of Plant Trait Data of Host Plants of Lycorma delicatula in the US Suggests Evidence for Ecological Fitting

Abstract

Plant traits, used by the invasive insect herbivores to find and select suitable hosts, can play an important role in insect host range expansion. With regard to invasive Lycorma delicatula, it is not well explored, however, how the plant origin affects insect host selection, and whether native and introduced host plants differ in their morphology, lifespan, as well as environmental requirements for growth. We addressed this issue in our study through the comprehensive assessment of 25 relevant plant traits (a total of 27,601 records retrieved from the TRY database), as well as the origin and phylogenetic relationships of 37 host plants of L. delicatula in the U.S. Our results showed that only leaf area, leaf chlorophyll content, and canopy size were significantly greater in the introduced hosts than that in native plants. We did not detect a significant effect of the plant origin on other characteristics. Additionally, no significant differences between native and introduced hosts of L. delicatula in genetic distances from introduced Ailanthus altissima (the most preferred host) were detected. These results, for the first time, suggest strong evidence for ecological fitting which might drive the host plant selection of L. delicatula and its rapid spread in the U.S.