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一、为害情况由于1975年推广使用 DDT 及1605两种农药,造成自1958年以来山楂红蜘蛛连年为害成灾,原因是一方面杀伤了大量的山楂红蜘蛛的天敌;另一方面是山楂红蜘蛛抗性种群的出现。山楂红蜘蛛在河北省果区作为主要害虫之一,每年至少防治1～2次。它主要为害仁果及核果类如苹果、梨、桃等的芽及叶片,严重时还可为害果实。芽受害严重时,不能萌发;叶片受害呈退绿小斑点,严重时变焦黄,一般不提前落叶,但如果早期受害严重时,会提前落叶形成二次花,影响树势。
First, the damage situation As the promotion of the use of DDT and 1975, two pesticides in 1975, resulting in hawthorn spider mites since 1958 years of damage, because on the one hand killed a large number of natural enemies of hawthorn spider mite; the other hand, hawthorn spider mite The emergence of resistant populations. Hawthorn spider mite in Hebei Province as one of the major pests, prevention and treatment of at least 1 or 2 times a year. It is mainly harmful pome fruit and stone fruits such as apples, pears, peaches and other buds and leaves, but also can be harmful in serious fruit. Bud serious damage, can not germination; leaf damage was green small spots, severe yellow, generally do not advance deciduous, but if the early serious damage, the formation of secondary flowers in advance deciduous, affecting the tree potential.