Impacts Of Native And Invasive Triadica Sebifera Volatiles On Olfactometer And Oviposition Experiments Of Different Feeding Habits Insects

Plants and insects are important components of terrestrial ecosystems. They formed many defense and adaptation mechanisms during the process of long-term coevolution. The pressure of insect feeding for Invasive plants in the places invaded may be reduced since the lack of specific feeding insects. This will lead to shift of insect defense strategy of invasive plants by reducing the resources for defense and allocating more resources for growth and reproduction.Triadica sebifera originates from China. It is a kind of perennial woody plants widely distributed in the Yangtze River basin and southern provinces. In recent years it has long been used as landscaping trees and considered to be an important source of plants biomass. Triadica sebifera reached the United States in the18th century. In the past30years it has become an important invasive plants in the United States. It posed a serious threat to local biodiversity. The existing studies have shown that the Triadica sebifera in invasion place has escaped the feeding insects and reduced chemical defense investment. And the invasion history and transmission of Triadica sebifera is relatively clear. It is easy to obtain the origin and evolution of plant material has invaded the relationship. The results are comparable. So Triadica sebifera is the ideal invasive species to research evolution of resistance.We select25Triadica sebifera populations including origin populations (China) and invaded populations (U.S.) with different evolutionary history, using dynamic headspace volatiles to collect the gas production from the plants and GC-MS to analysis material collected. Oviposition preferences experiments that can be controlled with different sizes sunshelter were carried out to study preference of specialist herbivore and generalist herbivore between Chinese tallow and America tallow which have various evolutionary histories. Insect adults were used to compare olfactory sensations between Chinese populations and American populations of Triadica sebifera experiments.Experiments show that the composition and content of volatiles from original and invasive Triadica sebifera populations were significant differences. The invasive populations have four times3-hexanol than native populations. Specialists prefer to select invaded populations, and lay more eggs in the invaded populations. But generalists prefer to lay eggs on the original populations. It means that invasive populations of Triadica sebifera has a significant repellent effect on general herbivores.This study reveals the direction and trend of geographic populations of plant chemical defense strategies and adaptive evolution under different selective pressures and the mechanism of interactions between invasive plants and insect relationships from the perspective of volatile substances.