烟粉虱成虫对黄瓜叶龄的喜好性及与后代发育适合度间的关系

在室内采用笼罩和发育测定方法,研究了烟粉虱成虫对黄瓜叶龄的喜好性及其与后代生长发育、存活之间的关系,同时调查了叶毛密度与成虫喜好性之间的相关关系。结果表明(1)烟粉虱成虫比较喜欢在黄瓜植株的中部叶片取食和产卵。(2)叶龄对烟粉虱的存活率没有显著影响,对烟粉虱的发育历期只在卵期和若虫四龄期表现出显著影响,对其他龄期或整个世代均没有显著影响。(3)叶毛密度随着叶龄的增大而顺次显著减小;在接虫初始阶段,烟粉虱成虫的叶片选择性与叶毛密度成显著负相关关系,但72h后具有中等叶毛密度的叶片上的成虫数量和着卵量均显著高于叶毛密度较大或较小的叶片。研究结果对培育抗烟粉虱的黄瓜品种和改进烟粉虱的防治措施具有一定指导意义。

Host leaf age preference of adult Bemisia tabaci (Homoptera: Aleyrodidae) and its relationship with offspring performance

Preference of Bemisia tabaci adults for cucumber leaf age and its relationship with offspring performance in terms of duration and survivorship were investigated in this experiment, and preference of whitefly adults was correlated to trichome density on leaves of different ages. Results show that (1) adult whiteflies preferred leaves in the middle stratum of cucumber plants for feeding and oviposition. (2) Leaf age had no significant effect on duration and survival of B. tabaci immatures, except durations of eggs and 4th instar nymphs. (3) Trichome density decreased significantly with increasing leaf age; and at the initial stage of exposure, B. tabaci adults preferred less-pubescent old leaves, but after 72 h, numbers of deposited eggs and adults were significantly higher on leaves with medium trichome density than those on leaves with high and low trichome density. Implications of the above results are discussed in relation with cucumber variety breeding for resistance to and improving control efficiency of B. tabaci.