【摘要】 在北京地区君子兰上粉蚧全年均有发生,为害严重,7、8、9月是盛发期。自8月15日至10月24日,分8次释放隐唇瓢虫2～3龄幼虫,每盆累计释放63头;11月14日检查,结果释放区比对照区每叶蚧虫数减少87.9％,每株卵囊减少75％、“蚧堆”减少91.2％。释放瓢虫抑制虫口后再施敌敌畏的综合效果比单施敌敌畏好。每株卵囊减少72.7％,“蚧堆”减少86.1％。因此,在8～9月应用隐唇瓢虫压低粉蚧种群的基础上,辅以一次药剂防治,减少了用药次数,达到最大程度的控制粉蚧虫口。更多还原

【Abstract】 The ornamental plant scarlet kafirlily, Clivia miniata [Amaryllidaceae] is usually infested by the scale Pseudococcus comstocki all year round in Beijing. The heaviest infestation occurs during July to September. Jn studies conducted in Beijing in 1989, eight releases of the 2nd-3rd instar larvae, of Cryptolaemus montrouzieri, which was introduced from Australia and propagated in Beijing, were made on potted kafirlily plants during 15 Aug. to 24 Oct. at a total releasing rate of 63 predators per plant. Sampling on 14 Nov. of the same year showed that the number of scales, per leaf and numbers of the egg masses and larva-clusters of the scale per plant were reduced by 87.9%, 75% and 91.2%, respectively, compared with those on the control plants without the predator. Applying DDVP after the scale population was suppressed by releasing the predator reduced the number of the scale egg masses and larva-clusters per plant,by 72.7% and 86.1%, respectively, compared with that of the plants treated with DDVP atone. These results suggested that optimal control of the scale infestation during July-September can be achieved by releasing C. montrouzieri during August-September supplemented with one application of pesticides.更多还原