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六星吉丁虫在柑桔上的发生规律及其防治 总被引：1，自引：0，他引：1
通过对危害柑桔的吉丁虫进行发生规律和防治对策的研究，结果表明：在街州柑桔上为害的吉丁虫与山杜英上为害的吉丁虫为同一种。该虫在衙州1a发生1～2代，以老熟幼虫侵入木质部筑蛹室休眠越冬或以低龄幼虫在韧皮部越冬。木质部休眠越冬幼虫4月底至5月化蛹，1代成虫主要集中在6月上旬至中旬，是主高峰；8月底、9月出现2代成虫，是次高峰。7月是1代幼虫为害高峰，9月后多有生活史重叠。该虫危害柑桔枝干，蛀食其韧皮部，初为害时部分枝干会出现流胶，后期造成树皮爆裂，皮层缺损或枝枯。提出了采取营林措施、检疫措施、人工、生物、化学防治等防治措施。 相似文献
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筛胸梳爪叩甲生物学特性研究 总被引：7，自引：0，他引：7
筛胸梳爪叩甲是目前笋用竹林主要的地下害虫.采用室内饲养与室外调查相结合的办法对该虫的形态特征、生活史及各虫态的生活习性进行研究.该虫4～5 a发生1代,以成虫及各龄幼虫越冬;4月下旬至6月底为成虫羽化期,5月中旬为羽化盛期;2-3月越冬幼虫开始活动,4月中下旬为幼虫活动盛期,6-8月幼虫进入越夏期,活动量减少,9月气温下降,幼虫又开始活动,11月进入越冬期;7月底至8月上甸,4年生幼虫老熟结土茧化蛹,蛹约经25 d羽化成虫越冬.防治建议幼虫期活动盛期(4月)用BT可湿性粉剂800～1000倍泼浇林地,或在垦复时用750 kg/hm2茶籽饼拌土施入.成虫期可用黑光灯诱杀,均有一定防治效果. 相似文献
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在乐陵县青刺蛾是枣树的主要食叶害虫。据我们观察,青刺蛾一年1代,以老熟幼虫在枣树根颈周围0—10厘米深的土层中结茧越冬。翌年6月中旬(14—18日)为成虫羽化出土始期,6月下旬(22—27日)为高峰初期;7月上旬(2—6日)为羽化高峰期;卵历期6—10天,平均8天;幼虫一生共9龄,历期40.3天。 幼虫在5龄前仅食枣叶上表皮和叶肉,呈米粒大小的透明斑;从6龄进入暴食期,将枣叶咬成缺刻状。自幼虫孵化至暴食期历时15天左右。防治此害虫应在其暴食期前进行。 据我们试验,防治4—6龄幼虫:(1)喷撒20％杀灭菊脂5000倍液,杀虫率为96.7％;(2)喷撒晶体敌百虫800倍液和50％1605乳油1000倍液,杀虫率为100％ 相似文献
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云杉梢斑螟生物学特性与防治 总被引：5，自引：0，他引：5
云杉梢斑螟以幼虫危害青海云杉新梢嫩叶，在甘肃省寿鹿山林区一年发生1代，以1龄幼虫在当年新梢基部和针叶中越冬，翌年5月中旬开始活动并危害新梢，6月中旬化蛹，6月底始见成虫，7月上旬末，中旬初达羽化高峰。7月中旬为产卵盛期，7月下旬幼虫孵化，幼虫轻微危害后于9月中，下旬进入越冬状态，6月中旬，用2.5%敌杀死乳油5000倍液或2.5%功夫乳油3000倍液喷雾，防治效果均在95%以上，用25%灭幼脲Ⅲ号悬浮液3000倍液喷雾，防治效果90%左右；羽化期可利用黑光灯诱杀成虫。 相似文献
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通过对无公害栽培苹果园山楂红蜘蛛发生分布规律及防治措施的研究发现，无公害栽培苹果园越冬态山楂红蜘蛛种群数量为平地园〉阳坡园〉阴坡园；越冬态山楂红蜘蛛在树体上集中分布在主干及第一层主枝的翘皮、环剥缝隙、剪锯口及气生根等处。从山楂红蜘蛛发生动态看，1a中有2次发生高峰，分别为3月底至4月初、6月底至7月初。早春彻底刮皮后，每株树上越冬态山楂红蜘蛛数量仅为未刮老翘皮树的3．77％；萌芽前喷5波美度石硫合剂防治越冬态山楂红蜘蛛，喷药7d后防效达90％以上；生长季应用1．8％阿维菌素3000倍液或24．5％绿维虫螨2000倍液控制山楂红蜘蛛危害的校正防效均在97％以上。 相似文献
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橄榄锄须丛螟在广东汕头1a4代，林间世代重叠现象严重。10月中旬至12月中旬，老熟幼虫陆续下树入土在表土层1～3cm处或枯枝落叶层结茧越冬。翌年3月上旬至4月中旬化蛹，3月中旬至4月下旬成虫羽化。4月上旬出现第1代幼虫，6月上旬出现第2代幼虫，7月下旬出现第3代幼虫，9月中旬出现第4代幼虫。11—12月可结合清园进行林地除草、松土，将表土及杂草堆成堆焚烧，消灭幼虫和蛹。在成虫羽化高峰时，采用DU一Ⅱ黑光诱虫灯可诱杀大量成虫。在幼虫为害高峰时，可采用90％敌百虫原药1500倍液、2．5％溴氰菊酯乳油2000倍液、2．5％功夫乳油2000倍液、90％万灵2000倍液进行防治以及保护天敌等综合措施，达到控制害虫为害的目的。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
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本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):472-479
Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken. 相似文献
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Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic
or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts
(stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea
(Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content
as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest
N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized
to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea,
largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for
N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant
components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N
released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures
were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality
components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in
the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols.
Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest
age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its
components are mixed. 相似文献
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A. Rigueiro-Rodríguez M. R. Mosquera-Losada E. Gatica-Trabanini 《Agroforestry Systems》2000,48(3):245-256
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste
disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization,
(2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two
pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea
(Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect
on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage
sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but
affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral
systems.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):166-178
This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes. 相似文献