法桐草履蚧的发生规律及防治研究

草履蚧是法桐的重要害虫.在石家庄地区1 a发生1代,以卵在寄主附近的泥土中越冬,每年2月上旬至3月中旬孵化为1龄若虫,3月下旬至4月上旬蜕皮为2龄,4月下旬雄虫羽化和雌虫交配后死亡.雌虫5月下旬由树干爬到树根附近疏松的泥土中产卵,度夏越冬至翌年2、3月份孵化,依其发生规律在防治上主要抓住若虫期、末期,分别用50%辛硫磷500×10-6(体积分数)和25%溴氰菊酯10×10-6(体积分数)和50%乐果喷雾及灌根.防效在95%以上.抑制天敌有红环瓢虫,蚜茧蜂等.

STUDY ON THE OCCURENCE LAW OF GIANT MEALY BUG AND ITS CONTROL

Giant mealy bug [Drosicha corpulenta (Kuwana)]seriously damages Eastern plane (Platanus orientalis L.)in Shijiazhuang. It has one generation per year and overwinters in soil near the host plant with egg. This pest insect hatches to first instar nymph in the first ten days of Feb to the middle ten days of March, and then moults to second instar mymph in the last ten days of March to the first ten days of Apr The male adult of the insect emerges in the last ten days of Apr and dies after mating. The female insect creeps to the soil near the root of host tree from stem and oviposit in the soil, and the eggs overwinter to Feb or March next year. The key period of controlling the pest insect is nymph stage. 50% phoxim and 25% deltamethrin can be applied to control it by spraying and watering root. Ladybird and parasitic wasp are the natural enemies of the pest insect.