A facilitated introduction? A new specialist herbivore on Chinese tallow

The Chinese Tallow tree, Triadica sebifera is a high-priority invasive from Asia that out competes native trees and can often establish monocultures in areas prone to disturbance. A new species of leaf mining moth, in the genus Caloptilia has been reported on T. sebifera in its invasive range in the southeastern U.S. with increasing frequency over the past 3-4 years. Caloptilia damage on T. sebifera can reach high levels, at which over 50% of the leaves are either mined or rolled by the larvae. Given the following evidence, many hypothesize that this herbivore is native to Asia:

1) This species of Caloptilia has been reported to be abundant and highly specialized on populations of T. sebifera in the U.S. which are known to originate from two regions of China. 2) T. sebifera is reported to be less resistant and more tolerant to herbivore damage in its invasive range, explaining how this leaf miner could have been previously undetected in Asia, yet is so prevalent in the U.S.

In the summer of 2010, field surveys were conducted in several provinces of Mainland China to test this Asian origin hypothesis. Here, we will report the results of that field season and discuss the implications in terms of multitrophic invasion ecology.