烟粉虱(Bemisia tabaci)的寄主选择性

通过田间系统调查、实验室嗅觉测定、笼内和培养皿内自由扩散观察,对烟粉虱的寄主选择性进行了研究.结果表明,在田间,烟粉虱对不同的寄主植物存在明显的寄主选择性,其中对茄子、花椰菜、黄瓜等植物具有较强的嗜性,而对蕹菜、芹菜、苋菜等植物的嗜性较差;烟粉虱对同一植物的不同品种也有明显的选择性.烟粉虱对寄主植物颜色有明显的选择性,选择结果与烟粉虱对这些寄主的嗜性趋势基本一致.烟粉虱对单株寄主植物的嗅觉反应不敏感,但对植物叶片的乙醇抽提物有明显的嗅觉反应,并表现出较强的寄主选择性.在养虫笼内,烟粉虱从虫源皿向寄主植物自由扩散的过程中,在不同寄主植物和同一植物的不同品种上着落的成虫数量不同,并且在一定的时间范围内,着落在寄主叶片上的虫量还会不断的发生变化.

Host plant selection of Bemisia tabaci (Gennadius)(Hemiptera: Aleyrodidae)

Through a systematic field survey, olfaction testing, and free diffusion observations in both of cages and petri dishes, the behavior and partial mechanisms of host selection of Bemisia tabaci Gennadius were investigated on different host plants. Our results showed that the whitefly was obviously characteristic in host selection. To different host species, the whitefly showed intensive preference for eggplant, cauliflower and cucumber, but non-preference for water spinach, celery and amaranth. The host selection was also observed among different cultivars. Moreover, we found that plant color was a factor determining host selection for B. tabaci. Although whiteflies did not make response to a single host plant placed to their vicinity, they could be attracted by ethanol extracts of host leaves, suggesting some chemicals in host leaves might also contribute the host selection. When the diffusion of B. tabaci from the source to host plants was observed in cages, we found that the numbers of B. tabaci landing on the surface of host leaves were greatly different among hosts and among cultivars during the period of free diffusion, and the population of B. tabaci on host leaves continuously changed within certain time range after this period.