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速生桉大害虫--油桐尺蠖 总被引:1,自引:0,他引:1
油桐尺蠖又名桉尺蠖、量步虫,属鳞翅目尺蛾科的一种食叶性害虫。幼虫食性较广,主要危害油桐,亦危害油茶、肉桂、板栗、柿、杨梅等经济林。随着速生桉大面积纯林的出现,油桐尺蠖在一些地区已成为速生桉主要害虫。1990年在维都林场首次大面积发生,受害桉林面积1.3万亩,其中受害严重达6500余亩; 2005年宜州、柳江等地相继大发 相似文献
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春尺蠖属鳞翅目、尺蛾科,是一种重要的阔叶树食叶害虫。除危害杨、柳、榆、胡杨等常用树种外,还大量危害杏、苹果等经济林树种。一般在早春时发生,幼虫危害树木幼芽、幼叶、花蕾,常暴食成灾,严重时可将树叶全部吃光。危害暴发后,轻则影响寄主生长;重则枝梢干枯,树势衰弱,导致林木大面积死亡。 相似文献
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大叶黄杨尺蠖(Abraxas miranda Butler)危害大叶黄杨,大发生时常将大叶黄杨叶片咀食光秃,影响树势生长或造成死亡。为寻求有效防治办法,自1984年起,对此虫进行了生物学特性观察和防治试验。 一、形态特征 (一)卵 近圆形,长0.72--0.77毫米,宽0.58—0.63毫米。初产时淡黄,后渐变为淡绿,孵化时为褐色。 相似文献
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近几年来,礼县苹果病害频繁发生,主要原因在于果园的管理和防治不够。经过全面地监测,掌握病害发生的规律,并在发病期进行有效地综合防治,降低了病虫害的发生,增加了农民的经济收入。 相似文献
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针对南方红豆杉苗木病害,通过大田育苗对比试验,研究探索有效的防治方法,以减轻其危害程度,达到提高苗木保存率的目的。 相似文献
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Javed Iqbal David A. MacLeanJohn A. Kershaw Jr. 《Forest Ecology and Management》2011,261(6):1106-1114
Hemlock looper (Lambdina fiscellaria fiscellaria (Guen.)) is an economically damaging defoliator that undergoes periodic outbreaks in Newfoundland, Canada. It defoliates and causes extensive tree mortality to its primary host, balsam fir (Abies balsamea [L.] Mill.). We quantified tree survival using data from permanent sample plots (PSPs) and growth reduction or release using dendrochronology, and related these impacts to defoliation severity determined from annual aerial defoliation survey data. Such impact relationships are necessary as a fundamental input to a Decision Support System. Growth and survival of balsam fir, black spruce (Picea mariana (Mill.) B.S.P.) and white birch (Betula papyrifera Marsh.) were assessed from 1996 to 2008 in 48 Newfoundland Forest Service PSPs, selected based on four classes of defoliation severity. Two years of severe (71-100%) defoliation resulted in almost complete mortality for balsam fir, 10 years after defoliation, whereas survival was 70-80% for black spruce and white birch. Lower defoliation severity (1-2 years of moderate (31-70%) or 1 year of severe) resulted in approximately 60% survival for balsam fir and no reduction in survival for black spruce and white birch. Maximum growth reduction of balsam fir was 10-15% with 1 year of moderate-severe defoliation, 35-40% with 2 years of moderate defoliation, and about 50% with 2 years of severe defoliation. Growth recovered to pre-defoliation rates 5 years after defoliation ceased in all severity classes. Growth reduction and recovery of black spruce were more variable and lower than for balsam fir, and white birch exhibited only minor (<10%) growth reduction during the defoliation year or 1 year after defoliation. Control measures should focus on avoiding severe defoliation for two consecutive years. 相似文献