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一、透翅蛾危害。(一)发生规律。该虫1年发生1代,以两龄幼虫在被害处皮下越冬,幼虫一生只危害树皮的新生组织。10年生以上的栗树,在干高1米以下有虫10头时,树冠一般无明显被害症状:有虫30头时,则新梢停止生长,叶片枯黄早落,部分大枝枯死;若有虫50头时,当年秋季即有整株枯死现象,即使以后不再遭受危害,2～3年后板栗树也会死亡。越冬幼虫翌年3月中下旬至4月上旬开始活动危害,随后上下蛀食韧皮部,虫道内充满木屑和虫屎(不排出虫道外)。7月
First, through the moth harm. (A) the law. The worm occurs 1 generation a year to two instar larvae in the victims of subcutaneous winter, the larval life only harm the new tissue of the bark. The chestnut trees above 10 years of age had no symptoms when the insect was below 1 meter in dry height. When there were 30 beetles, the shoots stopped growing and the leaves were yellowish and early fall, and some large branches died. 50, when the fall that year withered whole plant phenomenon, even if no longer suffer from harm, 2 to 3 years after the chestnut trees will die. Overwintering larvae in late March the following year to early April activities begin to harm, then eaten phloem up and down, the worm is filled with sawdust and insects (not exterminated). July