论文部分内容阅读
杨木蠹蛾是杨树的主要蛀干害虫,广泛分布于青海省东部河谷地区,为害性很大。 据观察,其在西宁地区三年一代,但需跨经四个年度。幼虫计有16个龄期,于树干内生活约25个月,老龄幼虫脱孔入土栖居约10个月,共历期35个月左右,其间要越冬三次。蛀害阶段分作三大龄群,即新产群、第二年群和第三年群,各龄群逐年演替。其蛀害活动也可大致区别为:边材期、心材期和脱蛀期。成虫夜间活动,趋光性弱,喜择树皮裂伤处产卵,树干1—1.5米的高度内着卵较集中,因而蛀害指数也较大。 药剂防治主要应“卡—关(侵蛀),堵—头(蛀害)”。试验证明,用以下剂量的农药作适期防治,可获较好的防效:(1)5—10月间,幼虫蛀害活动时,用40％乐果乳剂25—50倍液,注孔一次,熏杀中老龄幼虫。(2)6月中下旬至7月下旬,成虫产卵期间,用50％可湿性DDT粉剂25—50倍液或50％倍硫磷乳剂400—500倍液,喷布树干胸段2—3次,触杀初孵幼虫。
Populus woodworm moth is the main stem borer poplar, widely distributed in the eastern valley of Qinghai Province, highly harmful. It is observed that its three-generation generation in Xining, but to cross the four annual. There are 16 stages of larvae, living in the trunk for about 25 months, aging larvae into the soil dwelling about 10 months, a total of 35 months or so, during which three winters. The stage of calamity is divided into three major age groups, that is, new-producing group, second-year group and third-year group. The calamity activities can also be roughly divided into: sapwood, heartwood and decadent period. Adult activity at night, phototaxis weak, like to bark laceration spawning, 1-1.5 m height of the trunk within the eggs more concentrated, so moth damage index is also larger. Pharmacy should be mainly controlled “card - off (moth-eaten), plug - head (moth damage).” Experiments show that the following doses of pesticides for proper control, can be a better control effect: (1) May-October, larvae damage activity, with 40% dimethoate emulsion 25-50 times, perforated Once, fumigation of middle-aged larvae. (2) From mid-late June to late July, during the spawning period of adult worms, the thoracic trunk section 2-3 was sprayed with 25-50 times of 50% wettable DDT powder or 400-500 times of 50% fenthion emulsion Times, touch newly hatched larvae.