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梨大食心虫是果树生产中主要害虫之一,以幼虫为害梨芽、花序、叶序和果实。在发生区若不加防治,减产50—60％。一、防治指标依据梨大食心虫幼虫冬后活虫数和健芽数之百分率做为防治指标。入冬前在梨园中选样,从每树不同方位调查足够的梨芽,凑足30—50个有虫被害芽,依有虫被害芽数和全部被查梨芽中健芽总数求得其百分率,即越冬基数。翌春梨大食心虫幼虫转芽以前做幼虫越冬存活率调查,从越冬基数中扣除死亡率,为冬后基数,即为防治指标。在生产中,也可于早春梨大食心虫
Pear boreal worm is one of the main pests in the production of fruit trees, larvae damage pear buds, inflorescences, leaf order and fruit. In case of no prevention and treatment area, cut 50-60%. First, the prevention and control indicators based on pear large borer larvae live after winter and the number of germs as a percentage of control indicators. Pear in the sample before the winter, from each tree to investigate the location of adequate pear buds, gathered enough 30-50 insects buds, according to the number of victims of pests and pear buds were all check the total number of buds get the percentage , That is, overwintering base. Next spring pear heartworm larvae turn buds to do before larvae overwintering survival survey, deducted from the overwintering base mortality rate for the winter after the base, is the prevention and treatment targets. In production, but also in the early spring pear heart worm