Abstract:

The olfactory response of Chinese tortrix (Cydia trasias) adults to volatiles of five plant species was tested with a wind tunnel. The volatiles were extracted from the branches of each plant species with HS (Head-space) , and then analyzed with GC-MS. Some substance contents of the five plant volatiles were also determined. The results showed that olfactory response of the Chinese tortrix adult to volatiles from the five species was different. The selectivity of Chinese tortrix to Sophora japonica and Sophora japonica cv. pendula was more than 80.0%, however, the selectivity to Robinia pseudoacacia and Robinia pseudoacacia cv. idaho was lower than 40%. Acetic acid, phenyl-3-hexenyl ester and cis-3,7-Dimethyl-1,3,6-Octatriene were the specific volatiles of Sophora, and they probably attracted C.trasias. 1-Octen-3-ol and 3,5,5-Trimethyl-2-hexene existed in Robinia pseudoacacia and Robinia pseudoacacia cv. idaho might have repellent effect to Chinese tortrix. The ratios of carbon to nitrogen were the lowest(1.09) in Sophora japonica and highest(3.36) in Robinia pseudoacacia. The preference feeding of C. trasias was probably related to the lowest carbon to nitrogen of Sophora japonica.

Key words: Cydia trasias, host-selection, volatiles