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1.
栗山天牛幼虫和蛹在辽东栎树干上的分布规律 总被引：1，自引：0，他引：1
通过解剖受害辽东栎,结合林间调查,研究栗山天牛幼虫和蛹在栎树树干上的分布规律。结果表明:受害后表现为全部枯梢症状的栎树,栗山天牛幼虫主要分布在树干4m以下,蛹主要分布在1～4m;部分出现枯梢症状的栎树,栗山天牛幼虫主要分布在树干6m以下,蛹主要分布在3～7m。天牛数量与树皮厚度和树干直径均呈正相关关系。调查发现,当辽东栎树皮厚度大于0.47cm、树干直径大于9.02cm时,开始出现栗山天牛危害。在林间,栗山天牛低龄幼虫主要分布在树干阳面的韧皮部中,而蛹主要分布在木质部,越靠近树干中心分布越多。产卵当年和翌年6月前幼虫主要在韧皮部取食危害。从翌年6月开始,天牛幼虫逐渐蛀入木质部为害,7—8月为蛀入木质部的高峰期,9月绝大多数幼虫蛀入木质部取食,直至化蛹。树干2m以下的幼虫排粪孔数与树木胸径成正相关,而与最高活枝高度成负相关关系。当最高活枝高度在4～7m时,幼虫数量最多。 相似文献
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芳香木蠹蛾属鳞翅目木蠹科 ,在河北主要为害柳树、榆树 ,其次为害杨树、国槐等 ,以幼虫钻蛀树木枝干 ,常造成枯梢或整株死亡。1 生活史芳香木蠹蛾 2a发生 1代 ,第 1年以幼虫在树干内越冬 ,第 2年幼虫离开树干在土壤内越冬 ,第 3年春天化蛹 ,4月下旬至 6月中旬为成虫羽化期 ,5月上中旬为羽化盛期。成虫将卵产于树干分叉处 ,树干基部的树皮裂缝、伤口及旧蛀孔处。卵单产或堆产 ,卵期 15～ 2 0d。初孵幼虫群集蛀食韧皮部和形成层 ,随后蛀入木质部 ,被害处排出白色或赤色木屑。一直为害到 9月下旬 ,开始在虫道的末端越冬。第 2年 4月上旬幼虫常… 相似文献
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沙棘蛀士害虫柳蝙蛾的生物学特性及防治 总被引：3，自引：1，他引：2
柳蝙蛾是一种新的沙棘蚊干害虫,属鳞翅目,蝙蝠蛾科。在黑龙江省绥棱地区一般２年发生１代,少数１年发生１代,以孵和幼虫越冬,越冬幼虫从４月下旬开始危害至７月下旬;越冬卵孵化后,幼虫７月中旬至８月上旬开始钻蛀危害至１０月,然后以幼虫在树干基部越冬。采用２０％的速灭杀丁乳油,８０％敌敌畏乳油,在幼虫钻蛀前进行地面喷药防治,结合虫道“注液法”防治,防效可达９３．３％－１００．０％。 相似文献
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赣林1号树干注射防治杨小舟蛾试验 总被引：5，自引：0，他引：5
报道了利用树干注射赣林１号农药，对杨树食叶害虫杨小舟蛾幼虫的防治效果１００％，同时兼有抑制蛀干害虫星天牛的侵害，又能促进杨树胸高直径的生长 相似文献
6.
桃红颈天牛在果区以幼虫在树干蛀道内越冬,翌春恢复活动,在枝干基部皮层下和木质部钻蛀成不规则隧道,并向蛀孔外排出大量红褐色虫粪及碎屑,造成树干中空,皮层脱离,树势衰弱,常引起断折和整株死亡。防治方法： 相似文献
7.
云斑天牛Ｂａｔｏｃｅｒａｈｏｒｓｆｉｅｌｄｉ（Ｈｏｐｅ），在山东省２年发生１代，以幼虫或成虫在树干蛀道内越冬。成虫多将卵产于距地面１～１．３ｍ的主干弯曲处（成虫产卵前先咬刻槽，后将卵产于刻槽上方皮层和木质部之间），卵经１０～１５天后孵化幼虫，在韧皮部... 相似文献
8.
五个杨树品种对杨锦纹吉丁虫抗性的研究 总被引：1，自引：0，他引：1
杨锦纹吉丁虫(Poecilonota variolosa)是杨树主要钻蛀性害虫之一,分布于辽宁、吉林、黑龙江,内蒙古等省区.该虫的幼虫为害树干皮 相似文献
9.
蛀干害虫综合防治措施 总被引：1，自引：1，他引：0
危害林木钻蛀枝干的害虫主要包括天牛科的光肩星天牛、双条杉天牛,小蠹科小蠹虫类,象甲科杨干象甲,螟蛾科松梢螟,透翅蛾科白杨透翅蛾和木蠹蛾科芳香木蠹蛾等。其主要危害杨、柳、榆、槐、油松、樟子松、苹果树和梨树。这类害虫的幼虫钻蛀树干,被害处组织增生形成瘤状虫瘿,易造成树干枯萎,秋冬季节常引起风折,同时影响林木正常生长,树木畸形,影响成材、降低木材的商品价值。蛀食顶芽和枝梢,顶芽停长、徒生侧枝。此类害虫常以幼虫在枝、干里的隧道内越冬,幼虫在韧皮部、木质部内蛀成坑道,成虫羽化期分散, 相似文献
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冰冻雪压对杉木人工林近成熟林分危害调查 总被引：13，自引：0，他引：13
以受冰冻雪灾较为严莺的江西省大岗山林区杉木近成熟林分为研究对象,探讨杉木林分结构和立地条件与杉木受损类型及灾害发生程度的关系,得到几点主要结论:1)冰冻雪压造成大岗山林区杉木受害株数比例达66.84%,受灾相当严重,杉木林分受害类型可分为弯梢、断梢、斜干、断干、倒地及翻蔸等6种,其中断干和断梢为最主要的2种受害类型.2)杉木林分结构对冰冻雪压危害具有明显的调节作用,灾害主要发生于径阶相对较小的林木,林分内径阶越大的林木其受害程度明显越轻;林分密度与受害强度具极显著正相关,密度越高,林分受损株数愈多,且密度主要影响断干、翻蔸这2种不可逆的受损类型,合理的密度调控至关重要.3)杉木林分的立地条件与受害程度紧密相关,高海拔、高坡位、陡坡处的林分更易受到冰冻雪压的危害,较高的立地指数有利于杉木在遭受冰冻雪压灾害时减轻损失. 相似文献
12.
Kari KELIVAARA 《中国林学(英文版)》2008,10(1):9-13
After the outbreak of Dendrolimus superans Buter in 2002, many insect borers quickly invaded larch （Larix gmelinii Rupr.） forests in the Aershan of Inner Mongolia. Methods involved included setting sample plots, collecting adults in iron traps and measuring areas of galleries to study the invasive sequence, their ecological niche and the extent of the different effects by the main insect borers to their hosts. The results showed that the damage of D. superans weakened L. gmelinii, first Ips subelongatus Motschulsky invaded, followed by Acanthocinus carinulatus Gebler, Monochamus urussovi Fisher and M. sutor L. After the outbreak of D. superans, the average density of longhorn beetles per L. gmelinii tree increased. The ecological niche of Ips subelongatus stretches almost from the base to the top of the trunk. The number of insects in older stands of L. gmelinii is larger than those in middle aged stands. They do not damage healthy trees of L. gmelinii. The ecological niche of A. carinulatus is higher in dead L. gmelinii trees than in weak ones. The degree of damage is directly proportional with age and depth of bark. M. urussovi mainly damages trunks below 4 m in weak trees; in dead trees they can do damage up to 6 m in height. M. sutor mainly damages trunks below 5 m in weak L. gmelinii trees; in dead trees they cause damage up to 7 m. Again, the degree of damage is directly proportional with age. None of the three species of longhorn beetles damage healthy L. gmelinii and younger trees. Among the main insect borers, the degree of damage caused by I. subelongatus is more serious than that of other insects. 相似文献
13.
We examined the water status of Hinoki cypress, Chamaecyparis obtusa (Siebold & Zucc.) Endl., trees after a severe typhoon to determine possible causes of the decline and dieback that can occur in what appear, at first, to be healthy trees in typhoon-damaged forest stands. We found that in apparently healthy trees in a storm-damaged stand, the water conducting area of the trunk cross section was greatly reduced compared with that of similarly sized trees in a nearby undamaged stand. Although leaf specific hydraulic resistance (Wl) from soil to leaf and from trunk to leaf was higher in trees from the storm-damaged than the undamaged stand, Wl values from soil to root were similar. Diurnal patterns in the rates of change in trunk diameter differed between trees in the damaged and the undamaged stand. We conclude that increased aboveground hydraulic resistance caused by a reduction in trunk water conducting area could be a major reason for the decline and dieback of apparently healthy trees in typhoon-damaged stands. 相似文献
14.
Until recently, growth stress studies have been made only on coniferous and dicotyledonous trees. Growth stress of trees is thought to be initiated in newly formed secondary xylem cells. This stress can accumulate for years and is distributed inside the trunk. Major characteristics of the trunk of monocotyledonous trees include numerous vascular bundles scattered inside the ground tissue and the lack of secondary growth for enlarging the diameter of the trunk. We used the strain gauge method to measure the released growth strain of the monocotyledonous woody palm, coconut (Cocos nucifera L.), and to investigate the surface growth strain of the trunk and central cylinder at different trunk heights. The internal strains of both vertical and leaning trunks were measured and compared with those of coniferous and dicotyledonous trees. We found that tensile stress existed longitudinally on the surface of vertically growing trunks, whereas compression stress was found at the bending position of leaning trunks. Compression stress was found in the outer part of the central cylinder, whereas tensile stress is generally found in the outer part of the trunk in coniferous and dicotyledonous trees. The distribution of strain in the palm trunk is similar to that of compression wood of the leaning trunk of a conifer. Specific gravity was greater in the outer part of the trunk than in the inner part of the trunk. This difference may be related to the distribution of growth stress. 相似文献
15.
为了解Y形架不同整形方式对梨树生长结果的影响,研究了龙干式和二主枝2种Y形架整形方式下‘中梨1号’梨品种幼树树干直径、主枝直径、早期结果性能、果实品质等方面的差异。结果表明,龙干式整形的‘中梨1号’树干直径、主枝直径、40%以上节位结果枝条数、单株平均结果数等均显著高于二主枝整形的‘中梨1号’,表现出良好的幼树早期丰产性。但龙干式整形的树势相对中庸,果实平均单果质量略小于二主枝整形的‘中梨1号’。除了龙干式的果心占比稍大于二主枝‘中梨1号’,2种整形方式的‘中梨1号’果实在果形指数、果肉硬度和可溶性固形物含量等品质指标上并无显著差异。总体上,龙干式较二主枝式更容易整形,树势更中庸,幼树早期丰产性强,但需要强化水肥管理。 相似文献
16.
Li Wen-bin Sun Ren-shan Liu Xu-hua Liu Yong 《中国林学(英文版)》2006,8(1):46-49
For the demands of automatic pruning, an effective discrimination rule of the forked and non-forked larch trees is established. First, information of trunk and branch diameters of a larch plantations was collected from the west mountain of Beijing. The growth characteristics of the forked and non-forked trees were studied. Given the statistical characteristics of the trunk and branch diameters, a discriminant function of the forked branch and non-forked larch trees was established statistically. Excellent discrimination results were obtained by the function and the rule. The study presents an effective discrimination rule to separate forked trees from straight trees for automatic pruning. 相似文献
17.
We estimated the water status of six 31-year-old hinoki cypress (Chamaecyparis obtusa) trees that were struck by a large typhoon. Measurements were made of the trunk water-conduction area of xylem, leaf water potentials, and diurnal changes in trunk diameters. The secondary woodboring insects, Callidiellum rufipenne and Ovalisia vivata, on the trees were captured by the sticky-trap banding method. In trees on which these wood borers were captured, water conduction areas were reduced, leaf water potentials were lower, and trunk diameter changes (R) fluctuated during the day, suggesting that the trees had been damaged by the typhoon and were under water stress. The secondary woodboring insects attacked the water-stressed trees. 相似文献
18.
美洲黑杨优良无性系NL-80351推广初报 总被引：2，自引：0，他引：2
通过选择,引进了杨树NL-80351优良无性系,分别在应城市、大悟县、孝南区等地育苗试验和造林试验,以原有本地主栽品种I-69无性系作对照,经过连续6a的生长表现测定和统计分析表明NL-803514a生林分年平均高生长4.0m以上,年平均径生长4cm以上,而作对照的I-694a生林分年平均高生长2.6m,年平均径生长3cm左右。NL-80351干形园满通直、尖削度小、分枝角度小、冠幅窄、抗性强,未发现发生病虫危害,一般经营措施下林木生长旺盛,已成为孝感市主栽品种。 相似文献
19.
We compared seasonal changes in maximum diurnal trunk shrinkage (MDS) with seasonal changes in midday stem water potential (Psi(s)) over three years in plum trees grown in differing drip-irrigated regimes. In well-irrigated trees, day-to-day variations in Psi(s) and MDS were related to evaporative demand. Reference equations were obtained to predict MDS and Psi(s) values for well-irrigated trees as functions of environmental conditions. A decrease in plant water status toward the end of the growing season occurred even in the well-irrigated trees, probably reflecting a reduced volume of soil wetted by the drip irrigation system. Thus, for the prediction of Psi(s), different reference equations are required for the fruit-growth and after-harvest phenological periods. A seasonal change in the relationship between MDS and Psi(s) was observed, which compensated for the decrease in plant water status such that well-irrigated trees had similar MDS values during both the fruit-growth and after-harvest periods. The influence of tree size on the relationship between MDS and Psi(s) was also investigated. For tree trunk diameters ranging between 8 and 13 cm, MDS increased 13% for each cm of increase in trunk diameter, as a result of the thicker phloem tissues of the larger trees. This finding may allow extrapolation of Psi(s) predictions based on empirical relationships with MDS to plum trees of different sizes. 相似文献
20.
In a mature beech stand located in north-eastern Germany, xylem sap flux measurements were continuously performed during the 2002–2004 growing seasons. Ten representative trunks were studied using heated thermal dissipation probes. The measurements aimed at identifying principles governing radial profiles of xylem flux in beech trunks. The measurements were taken up to a trunk depth of 132 mm. The sap flow density in the pericambial xylem was found to vary among trees of different diameters, but was not considerably smaller in suppressed trees. A model for the radial distribution of sap flux density was formulated relating trunk radius and sap flow density. The model takes into account different trunk diameter. About 90% of the sap flux was found to occur in the outer two fifths of the trunk. Using this model, an adequate estimate of transpiration can be achieved at tree and stand level, even when the sap flux measurements are restricted to the outer trunk sectors. 相似文献