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一、桑天牛的发生规律桑天牛,俗称“蛤虫”。属鞘翅目、天牛科。2—3年发生一代,以幼虫在被害枝干中越冬。第三年夏天,老熟幼虫羽化后钻出枝干,啃食嫩芽、叶片和枝干的皮层。半月后,开始产卵。卵产于小枝伤口中,每头天牛一生可产卵百余粒,成虫寿命30—40天左右。卵孵化后的幼虫先向枝条上方蛀食几毫米,然后调头向下危害,每蛀食5毫米左右向外蛀一排粪孔,以排出粪便。每个幼虫一生可蛀隧道达2米以上。在滦南县桑天牛6—7月份和9—10月份是两个危害高峰。
First, the law of mulberry days Mulberry, commonly known as “clams”. Coleoptera, Cerambycidae. A generation of 2-3 years to larvae wintering branches in the winter. In the third year of summer, mature larvae drilled branches after emergence, grazing on the cortex of shoots, leaves and branches. Half a month later, start spawning. Eggs produced in the branchlet wound, each head of life can spawn more than 100 tablets, adult life of about 30-40 days. Egg larvae hatch first to the top of the branches a few milliliters, and then turn down the hazards of about 5 milliliters per bore eaten a row of manure holes to excretion. Each larvae can erode tunnel life of 2 meters or more. Mulberry in Luannan County in June-July and September-October are two dangerous peaks.