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杨白潜叶蛾是为害杨树幼苗、幼树的一种较严重的害虫。幼虫在表皮下潜食叶肉,形成黑色虫斑。在河北易县为害多种杨树,其中毛白杨、唐柳虫斑面积占全株叶片面积达20％以上,严重影响光合作用的进行,树势衰弱,往往提早落叶。 此虫在易县一年发生四代,9月中旬至10月上旬相继以蛹作“工”字形茧在树干树皮缝内、落叶上越冬。同时有一小部分蛹羽化,成虫交配后产卵并孵化,但小幼虫在10月下旬全部冻死在潜叶上。成虫在4月中旬开始出现。有趋光性。产卵在叶片正面贴近主脉或侧脉,通常5—7粒卵排列成行。每头雌虫平均产卵量为49粒。幼虫孵化后从卵壳底面(与叶正面表皮接触处),咬破卵壳潜入叶组织内取食叶肉。 防治方法:秋冬季节在苗圃、幼林内大量扫集落叶,可消灭一定数量的越冬茧;根据室内和苗圃大面积防治幼虫试验,用40％的乐果乳剂1:1,000倍液喷洒叶面,毒杀潜叶内的幼虫效果很好。
Yang white leaf moth damage poplar seedlings, saplings of a more serious pests. The larvae lay on the epidermis to eat the mesophyll, forming a black bug. A variety of poplar damage in Yixian County, including Populus tomentosa, Tang Willow plaque area accounted for more than 20% of the total leaf area, seriously affecting the conduct of photosynthesis, tree weakness, often early leaves. This insect occurred in Yixian four generations a year, from mid-September to early October have to pupa for “workers” shaped cocoon in the trunk bark stalks, falling leaves on the winter. At the same time, there is a small part of pupa eclosion. The adults lay eggs and hatch after mating, but the small larvae all freeze dead on the leaves in late October. Adults began to appear in mid-April. A phototaxis. Spawning close to the main vein or lateral veins on the front of the blade, usually 5-7 eggs arranged in rows. The average fecundity per female is 49 grains. Larvae hatch from the bottom of the egg shell (contact with the front of the leaf epidermis), bite the eggshell into the leaf tissue to eat mesophyll. Prevention and treatment methods: autumn and winter in the nursery, young forest sweeping large numbers of deciduous trees, can eliminate a certain number of wintering cocoon; indoor and nursery large area control larvae test, with 40% dimethoate 1: 1,000 times spraying foliar, toxic Killing the larvae within the leaf is effective.