Xie, Y.P., Xue, J., Yang, X., Zhao, Y., He, J., Zhang, Y.F., Chang, X., & Du, X. 2008 Japanese wax scale inducing persimmon trees to change their volatiles so as to attract the natural enemies.. Proceedings of the XI International Symposium on Scale Insect Studies, Oeiras, Portugal, 24-27 September 2007. ISA Press Lisbon, Portugal 322 pp.
Notes: Abstract: Japanese wax scale, Ceroplastes japonicus Green (Hemiptera: Coccoidea: Coccidae), is an important pest of persimmon, Diospyros kaki, in north China. In this paper, the effect of damage by C. japonicus on the emission of volatiles from the persimmon canopy and its effect on the attraction of three predators, namely the two lady-beetle, Chilocorus kuwanae Silvestri and Harmonia axyridis Pallas and a green lacewing, Chrysopa sinica Tiedet, were evaluated. The volatiles were collected from twigs and leaves on sample trees 111 the forest by using a headspace volatile trarping instrument. Twigs and leaves were sampled from 3 classes of damage by the Japanese wax scale: i) severe damage, ii) light damage and iii) almost no damage. Volatile compounds were analyzed by using TCT-GC-MS equipment. A glass Y-tube olfactometer was used to test the attractive activity of the volatiles emitted from the damaged twigs and leaves to the natural enemies. The results showed that the damaged twigs and leaves attracted significantly greater numbers of individuals of the three predators than the undamaged leaves in a proportion of 7-±.17%, 66.67% and 66.67% for Chilocorus kuwanae, Harmonia axyridis and Chrysopa sinica respectively. The attraction strength varied with season; the most significant attraction effect bein8 displayed in the autumn. The diurnal rhythm also effected the attraction effect, the most significant attraction being detected at midnight and at noon. In total, 60 compounds were detected from the volatile samples from the damaged persimmon trees, including 17 terpenoids (62.68%) and 6 alcoholic compounds (7.52%). Six compounds were selected for bioassay trials, of which two, a-pinene and Iinalool, showed a remarkable attractive effect to the predator Harmonia axyridis,