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我们养植的桂花在夏秋季经常会出现这样的现象:浓绿的叶片失去了光泽,出现失绿小点,长势衰弱没有生机,严重时一片苍白(如图),而后便出现大量落叶和枝条干枯。这是由红蜘蛛为害所致的。为害桂花的红蜘蛛主要有柑桔全爪螨和长全爪螨。柑桔全爪螨在华南一年发生20多代,长江流域15～19代。每代经历卵、幼螨、若螨、成螨4个阶段,以卵和成螨在枝条裂缝及叶背越冬。发育历期随温度升高而缩短,气温20℃时完成1代需29天,35℃时为10.2天。一般29℃～30℃间为发育和繁殖的适温范围,25℃为最适温度。雌虫一
The sweet-scented osmanthus we cultivate often shows such phenomena in summer and autumn: the leaf of green leaves loses its luster, the point of loss of green appears, the weakness of life is weak, and pale (pictured) in severe cases, then a large number of fallen leaves and branches Dry. This is caused by the spider mite. Osmanthus spider damage mainly citrus red mite and long full-mite. Citrus red mite mites in South China occurred more than 20 generations a year, the Yangtze River Basin 15 to 19 generations. Each generation experiences eggs, young mites, nymphs and adult mites in four stages. The eggs and adult mites winters through branches and leaves. Developmental period shortened with increasing temperature, when the temperature was 20 ℃, it took 29 days to complete the first generation and 10.2 days at 35 ℃. General 29 ℃ ~ 30 ℃ for the development and breeding of the suitable temperature range, 25 ℃ for the optimum temperature. Female one