应用性诱剂测报与防治桑蛀虫的研究

性诱剂防治桑蛀虫试验结果表明，诱杀防治区的株受害率下降60.90％，枝受害率下降66.83％；迷向防治区的株受害率下降54.67％，枝受害率下降62.15％。性诱剂引诱蛾量高峰日可以代表发蛾高峰日,作出虫情预报。     

Effects of application rate and interval on the efficacy of sprayable pheromone for mating disruption of the oriental fruit mothGrapholita molesta

The efficacy of microencapsulated sprayable pheromone was evaluated at different application rates and intervals for mating disruption of the oriental fruit moth,Grapholita molesta (Busck), in apple orchards during 2002. The following treatments were arranged in a randomized complete block design with three replications: (i) a low rate of pheromone (6.2 g a.i. ha⁻¹) applied at 14-day intervals, (ii) a medium rate of pheromone (12.4 g a.i. ha⁻¹) applied at 28-day intervals, (iii) a high rate of pheromone (24.7 g a.i. ha⁻¹) applied at 28- day intervals, and (iv) a non-pheromone control (insecticides only). The combination of a single insecticide application against first generationG. molesta at petal fall with one pheromone application each for the second, third and fourth generations at 12.4–24.7 g a.i. ha⁻¹ successfully controlled low populations. Pheromone-treated blocks. had significantly lower trap catches than those in the insecticide-treated control blocks. Among pheromone treatments, significantly more moths were caught in the 6.2 g compared with the 12.4 and 24.7 g rates. Fruit damage was <1% at harvest and there were no significant differences among treatments. Low rate frequent applications of sprayable formulation appeared to be effective under low pest pressure but efficacy declined with increasing populations. Further studies are needed to demonstrate the effectiveness of this approach under higher pest pressure. http://www.phytoparasitica.org posting July 13, 2005.     

斜纹夜蛾性诱剂诱杀成虫的效果

进行了斜纹夜蛾性诱剂和诱捕器诱杀斜纹夜蛾成虫效果对比试验。试验结果表明,从诱杀斜纹夜蛾效果来看,以放置宁波斜纹夜蛾性诱剂和UMT-B诱捕器诱蛾效果最好;从放置斜纹夜蛾性诱剂诱芯的个数来看,则以UMT-B诱捕器放置诱芯3枚的效果最好,其次是2枚、1枚。     

烟草甲性信息素及其异构体的简易合成法

从2,4-二甲基戊二酸出发,经酯化、还原、格氏反应、选择性保护分子中的一个羟基后,再经氧化及脱保护反应,以61%的总收率合成了烟草甲性信息素及其异构体——4,6-二甲基-7-羟基-3-壬酮(7);7经脱水环化反应,得到另一种烟草甲性信息素及其异构体——2,6-二乙基-3,5-二甲基-3,4-二氢呋喃(8)。各产物结构均经核磁共振氢谱、碳谱及质谱分析确证。     

几种因素对斜纹夜蛾性信息素诱捕效果的影响

采用田间诱集效果测定,就不同来源诱芯、诱捕器不同置放高度、不同类型诱捕器、诱芯不同储藏期等因素对信息素诱集斜纹夜蛾数量以及时序动态的影响进行了研究,以探讨蔬菜害虫斜纹夜蛾性信息素应用的关键技术。结果表明:3种不同来源的斜纹夜蛾性诱剂诱捕效果无显著差异;斜纹夜蛾性信息素置放高度依据不同寄主田间生长高度,以1～1.5m效果较好;3种诱捕器诱集效果相当,诱集代次清晰、峰谷明显,均可作为斜纹夜蛾性信息素配套的诱捕器;斜纹夜蛾橡皮塞诱芯置放冰箱贮藏1年或2年,诱蛾活性显著下降,诱蛾量下降60%以上。     

云杉八齿小蠹化学生态的研究进展(鞘翅目,小蠹科)

本文对云杉八齿小蠹化学生态的研究进展进行了综述。云杉八齿小蠹在中欧的大面积爆发激发了广大林业科学工作者对其化学生态学的广泛研究。在寻找寄主的过程中,雄性找到寄主后释放化学信息物质吸引雄性和雌性的聚集。开始发起进攻的小蠹在找寻寄主的过程中能利用寄主树脂作为利己素,并能够在体内解毒后合成可被利用的化学信息物质。在云杉八齿小蠹雄性的中肠中,我们发现9种单萜类化合物,主要是反式马鞭草烯醇和2-甲基3-己烯2-醇,这两种物质被认为是云杉八齿小蠹聚集信息素的主要成分。小蠹二烯醇的含量虽然很低但是能显著提高马鞭草烯醇和2-甲基3-己烯2-醇的野外诱集作用。马鞭草烯酮和小蠹烯醇是反聚集信息素,在调节攻击密度和树皮下的种群密度的过程中起着重要的作用。本文主要综述了寄主抗性、信息素成分和小蠹虫行为之间的关系。野外生测的结果证明利用信息素防治云杉八齿小蠹是行之有效的防治方法。     

基于水土保持的宜宾市土地利用空间重组

该文在GIS技术支持下分析了宜宾市水土流失与土地利用间的相互关系,以期为宜宾市土地利用空间重组提供战略思路。结果表明,水土流失多发生在自然因素与人类活动强度吻合较好的地方。因此,土地利用空间重组的目标即是通过土地利用的调整,规避生态敏感区或以能够逆向调节区域生态敏感性的方式利用土地,以有效的减缓水土流失。该文还提出了宜宾市土地利用空间重组的基本模式,即“结构调整+空间集聚”。     

Aggregate breakdown during tillage in a Mediterranean loamy soil

Long-term tillage negatively affects soil aggregation, but little is known about the short-term effects of tillage. We investigated the effects of intensive tillage (moldboard plowing) and conservation tillage (chisel plowing) on aggregate breakage during tillage in a long-term study located in the semiarid Ebro river valley (NE Spain). The type of tillage resulted in different soil aggregate distributions. In the 0–5-cm and 5–10-cm soil layers, chisel plowing decreased dry mean weight diameter (DMWD) 29% and 35%, respectively, while moldboard plowing decreased DMWD by only 2% and 16%, respectively. The decrease in DMWD was mainly due to breaking of large aggregates ranging (2–8 mm) into small aggregates (<0.5 mm). Tillage method had no effect on water stability of 1–2 mm aggregates. The differences in DMWD demonstrate that the choice of the tillage implement can be a key factor in improving soil management and productivity. The surprising result that aggregate breakdown was greater with chisel than moldboard plowing needs further research to determine the mechanisms controlling aggregate breaking during tillage.     

A review： chemical ecology of Ips typographus （Coleoptera, Scolytidae）

Chemical ecology of the spruce bark beetle lps typographus （L.） was reviewed. The outbreak of 1.typographus in central Europe triggered extensive research on chemical ecology, Males initiate host location and produce semiochemicals which attract both males and females, A successful mass attack must first overcome the resistance of the host tree. Pioneer I. typographus evolved to use the resin flow of host trees as kairomones in host location, and synthesized semiochemicals initially to detoxify the resin. If small bark beetle populations infest healthy trees, mass attack is prevented by host resistance, Nine monoterpene alcohols were found in male hind-guts, including cis-verbenol （cV） and 2-methyl-3-buten-2-ol （MB） which are regarded as primary aggregation pheromones, and a low proportion of lpsdienol （ld） which increases attractiveness of cV and MB, Verbenone （Vn） and Ipsenol （le） are anti-aggregation pheromones, that play important roles in adjusting attack density and insect density under the bark. Non-host volatiles are repellent to L typographus, so that beetles do not waste energy boring into non-host trees. The relationship between host resistance, pheromone compounds and behavior, non-host volatiles, bioassays and mass trapping are reviewed, Results of field bioassays stressed that traps baited with specific pheromones could be used as a reasonable protection measure.     

生态学实习中植物种群空间格局研究内容的改进

以1 hm2马尾松次生林为试验样地,调查全部植株不同维度的生物学参数,采用相邻格子法对比分析了多维度下种群属性参数的空间格局类型、聚集强度及其复杂性。结果表明,马尾松单株属性参数的变异系数表现为三维参数(植冠体积、地上生物量、叶生物量和枝生物量)二维参数(冠幅面积)一维参数(株高、胸径、冠幅直径)的趋势。株数的空间格局具有强烈的尺度依赖性,即随尺度增大其格局类型由均匀分布变为聚集分布;其他属性参数始终为聚集分布,但聚集强度均随尺度增加而增大。各参数的变异系数随尺度增大均显著减小,但变异复杂程度不完全相同,其中植冠体积变异复杂性最高,而地上生物量最低。可见,仅株数一个参数并不能全面反映种群空间格局特征,需结合其他属性参数来共同表征。