Studies On The Chemical Mechanism Of Bemisia Tabaci (Gennadius) B-Biotype In Host Plant Orientation

Bemisia tabaci B-biotype (expressed by Bemisia tabaci as follows) is a devastating pest of vegetables, ornamentals and other agronomic crops throughout the tropical and subtropical regions of the world. As an alien invasive insect, B. tabaci occurred greatly and caused a serious economical loss in China in recent years, and the trend is becoming more and more serious. Because B. tabaci is a polyphagous herbivore, phytochemicals serves as important messengers in the interaction between plants and the pest. So it is important to study the mechanism of orientating behavior of B. tabaci by chemical ecology and behavioral ecology. The studies will also help understand the spreading and adoption of B. tabaci, and provide information for controlling it. The orientating behavior of B. tabaci to host plants and its chemical mechanism were studied. The main results are summarized as follows.1 The tendency of female adults of B. tabaci to different host plantsFeeding preference and egg-laying preference of adults of B. tabaci to five species of host plants were performed in Lab, the results showed the adult preferred to feed on tomato leaves, lay eggs on cabbage leave. The number of adult on tomato ranked No. one, followed by cabbage, cotton, tobacco and pepper, however, the number of laying-egg on cabbage leaves ranked No. one, followed by tomato, cotton, tobacco and pepper.2 Attractiveness of volatile infochemicals from host plants to the female adult of B. tabaciThe role of volatile cues from three species of host plants in the host-selection behavior of B. tabaci was investigated by Y-tube olfactometer. The result indicated tomato leaves and cabbage leaves can arise oriental flight, however the pepper leaves have no attractiveness (P = 0.6890). When odors from the three host plants were compared, the female adult shows the strongest host preference to tomato, followed by cabbage and pepper leaves.3 Orientating behavior of female adults of B. tabaci to the color of host plant leaves3.1 Orientating behavior to the green leaves of different host plantsThe green leaves of tomato, cabbage and pepper all showed the significant attractiveness to B. tabaci adult respectively, the orientating rate was about 70%. And there was no significant difference among three host plants.3.2 Orientating behavior to different color leaves of host plantsB. tabaci Adults were not attracted by the red color, but the green ones and the yellow ones. When B. tabaci were faced with both the green and the yellow at the same time,...