The EAG response and behavior of the Saperda populnea L. to volatiles from poplar branches

In order to investigate the effect of organic volatiles from poplar species on the host plants orientation of Saperda populnea, the essential oil in the 2–3 years old branches from the sapling or mature trees of Populus simonii Carr. and P. simonii Carr. × P. nigra L. were extracted using the steam distillation method. The chemical composition and relative content in essential oil from those branches was analyzed by GC–MS. The main components contained in those volatiles from the four kinds of branches are mainly aromatic compounds such as 1,2-cyclohexanedione, 2-cyclohexene-1-one, p-xylene and 1,2,3-trimethylbenzene and so on. The relative content of aromatic compounds contained in branches from saplings was higher than that contained in branches from old tress. EAG response and behavioral reaction of S. populnea L. to those four kinds of distillated essential oil were tested. The results shown that male and female adults of S. populnea L. shown significant choice behavior and strong olfactory response to those essential oil distillated from branches of P. simonii Carr. and P. simonii Carr. × P. nigra L.. The EAG bioassay of S. populnea L. to 10 kinds of monomers compounds which had relative higher contents was tested. The results shown that the EAG response of female adults of S. populnea L. to 1 mol L⁻¹ p-xylene was intensest and reached 1.027 mV, the strength of their EAG response to 0.1 mol L⁻¹ phenol took the second place. The EAG response of male adult of S. populnea L. to 1 mol L⁻¹ p-xylene was strongest and reached to 0.824 mV, the strength of their EAG response to 1 mol L⁻¹ salicylaldehyde took the second place. In the choice behavior test of S. populnea L. adult to monomeric compound carried out in ‘Y’ type olfactometer have found that female and male adult of S. populnea L. all appeared obvious positive taxis to 0.1 mol L⁻¹ p-xylene. The selection rate of female and male adults ware (76.7 ± 4.1)% and (71.7 ± 2.6)%, respectively. The selective reaction to 0.1 mol L⁻¹ 1,2-cyclohexanedione and 2-cyclohexene-1-one were not obviously than that to 0.1 mol L⁻¹ p-xylene. The male and female adult of S. populnea L. appeared repelling behavior to 0.1 mol L⁻¹ salicylaldehyde.