黄缘阿扁叶蜂生物学特性及防治

黄缘阿扁叶蜂危害巴尾松针叶，在广西贺县一年发生１代，以老熟幼虫入筑室而以预蛹越夏，越冬，翌年１月中旬开始化蛹，２月上旬始见成虫羽化，３月初成虫开始产卵，３月中旬卵开始孵化，幼虫历期３０６天，应用９０％敌百虫或８０％敌敌畏４０００倍液喷杀３龄前幼虫效果好。     

黄缘阿扁叶蜂生物学特性及防治

黄缘阿扁叶蜂ＡｃａｎｔｈｏｌｙｄａｆｌａｖｏｍａｒｇｉｎａｔａＭａａ危害马尾松针叶，在广西贺县一年发生１代，以老熟幼虫入土筑室而以预蛹越夏、越冬，翌年１月中旬开始化蛹，２月上旬始见成虫羽化，３月初成虫开始产卵，３月中旬卵开始孵化，幼虫历期３０６天。应用９０％敌百虫或８０％敌敌畏４０００倍液喷杀３龄前幼虫效果好。     

樟子松木蠹象生物学特性的研究

樟子松木蠹象主要危害樟子松枝和主干。在长春地区，1a发生一代，以成虫在枯枝落叶层下浅土层内和树皮裂缝内越冬。第2年4月下旬越冬成虫开始活动，5月中旬开始产卵，高峰期5月下旬；孵化高峰期为6月上旬；6月下旬化蛹，高峰期为7月上旬；7月上旬羽化，高峰期为7月中旬。卵期平均14d，幼虫期平均34d，蛹期平均12d，成虫期长达300～330d；幼虫分6个龄期。     

柳乌蠹蛾的生物学特性及防治

柳乌蠹蛾是吉林省西部阔叶树的主要蛀干害虫之一，严重影响木材质量。该虫以幼虫越冬，在白城市区2al代，成虫羽化盛期为6月22日至7月15日，卵期14～24d，孵化率较低，成虫趋光性较强。可用黑光灯诱杀成虫；也可用40％乐果乳油加柴油(1：9)或50％杀螟松乳油点涂虫孔，杀虫率达100％。     

白杨叶甲生物学特性观察及防治

白杨叶甲在河北省平泉县1a发生2代,以成虫在枯枝落叶下和表土内越冬,4月中旬杨树发芽时开始上树取食危害,4月下旬开始产卵,5月上旬卵孵化为幼虫,6月初开始化蛹,6月10日左右出现第1代成虫。6月下旬出现第2代卵,7月上旬出现第2代幼虫,7月下旬出现第2代蛹,8月上旬出现第2代成虫,9月下旬成虫下树越冬。     

桃蛀螟对板栗为害及其防治

桃蛀螟(Dtchocrocis punctiferalisGuence)一般为害桃,李、苹果等果树及向日葵,玉米等农作物。近年来邳县板栗受该虫为害也十分严重,虫果率在10～15％左右,使板栗丰产不能丰收。 1 发生及危害 桃蛀螟成虫羽化期与温度有关。一般平均气温20℃,相对湿度75％～80％较适合蛹羽化。5月下旬成虫羽化3～4天左右开始产卵,5～7天卵孵化,其幼虫主要为害桃树果实。6月下旬幼虫老熟化蛹,7月上旬羽化,中旬成虫在板栗球苞上产卵,幼虫一孵化就钻入球苞,为害幼嫩的坚果。当幼虫2～3龄时,球苞很快变色干枯,有的脱落。7月下旬幼虫严重蛀果,蛀果率2.5％～3％,8月上旬幼虫老熟化蛹,下旬成虫大量发生并在球苞上产卵,卵孵化后,幼虫破坏球苞苞针外壳,钻进坚果,蛀食果肉,蛀果率达     

杨卷麦蛾的生活习性及其防治方法

杨卷麦蛾在白城地区一年一代、以卵在枯枝基部韧皮缝内越冬,翌年4月中旬孵化幼虫,5月下旬开始在被害的卷叶内化蛹;6月中旬成虫开始羽化;7月中旬开始产卵;8月中旬为产卵末期,在幼虫转移期,用50%的二溴磷乳油或50%的马拉硫磷乳剂1000倍液毒杀,效果可达90%以上。     

榆举肢透翅蛾生物学习性初步观察

榆举肢透翅蛾主要为害榆树,已知分布陕西、宁夏,两年1代,以幼虫在坑道内越冬。老熟幼虫于6月下旬开始化蛹,7月中旬成虫出现,7月底至8月上旬达盛期,初孵幼虫于7月下旬始见,10月下旬幼虫进入越冬,成虫白天羽化,交尾,产卵。卵单粒散产,卵期13—19天。成虫寿命1—8天,雌虫平均3.3—4.4天,雄虫平均2.3—3天,雌雄性比1∶0.77—1。     

灭幼脲防治黄地老虎的试验研究

灭幼脲可以同时杀死黄地老虎的卵，幼虫，亦可杀死部分成虫，并且要使未被杀死的雌成虫产卵和卵孵人受到极大的抑制。灭幼脲油剂杀死幼虫８４．０３％－１００％左右，胶悬剂杀死幼虫８２．６４－９８．６１％左右；灭幼脲油剂杀死卵８３．３３－９２．８６％左右，胶悬剂杀 卵５．５５－２２．２２％左右；灭幼脲油杀死成虫８．３３－９．０３％左右，胶悬剂可杀死成虫７．６４－９．７４＾左右。     

长白山露水河地区银杏大蚕蛾生活史及习性的初步研究

通过对银杏大蚕蛾的形态特征、生活史和生活习性的观察得出:长白山露水河地区银杏大蚕蛾1年发生1代,以卵在核桃楸树干上的树皮裂缝中越冬;翌年5月下旬卵开始孵化,幼虫大多为6龄,幼虫期约为60天;6月下旬至7月上旬,幼虫进入暴食期,7月中下旬开始在灌木丛上结茧化蛹,9月羽化成虫,中下旬产卵越冬。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

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.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

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.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

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.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

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.     

CAD与建筑设计的关系

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

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.     

Interactions in decomposition and N mineralization between tropical legume residue components

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.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

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.