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1.
变色夜蛾幼虫主要危害观赏树木合欢,其成虫颜色有浅有深,前翅有黑棕色斑点1~5个,同一数量的斑点有斑点分离型、斑点愈合型、斑点镶嵌型和白斑镶嵌型的变化。经研究发现有41种斑点排列,有的成虫左右翅斑点排列也不一样,这在鳞翅目昆虫中实属罕见。该虫在河北冀东地区一年发生两代。以蛹越冬,蛹期269d。翌年6月上旬为羽化盛期,6月~7月产第1代卵,6月中旬~7月下旬幼虫作害。幼虫经7龄,第1代蛹期15~17d,7月下旬出现成虫,7月下旬~9月上旬产卵,7月中旬~8月中旬幼虫作害,9月上旬陆续化蛹越冬。  相似文献   

2.
变色夜蛾幼虫主要危害观赏树木合欢,其成虫颜色有浅有深,前翅有黑棕色斑点1~5个,同一数量的斑点有斑点分离型、斑点愈合型、斑点镶嵌型和白斑镶嵌型的变化.经研究发现有41种斑点排列,有的成虫左右翅斑点排列也不一样,这在鳞翅目昆虫中实属罕见.该虫在河北冀东地区一年发生两代.以蛹越冬,蛹期269 d.翌年6月上旬为羽化盛期.6月~7月产第1代卵,6月中旬~7月下旬幼虫作害.幼虫经7龄,第1代蛹期15~17 d,7月下旬出现成虫,7月下旬~9月上旬产卵,7月中旬~8月中旬幼虫作害,9月上旬陆续化蛹越冬.  相似文献   

3.
蓝目天蛾在西宁地区每年发生2代,以蛹在寄主植物附近5—10cm深的土层中作土室越冬。翌年5月中旬开始,越冬代成虫陆续羽化出土,6月中旬达到高峰。当年第一代成虫7月下旬始见,8月下旬至9月上旬达到高峰。成虫具有较强的趋光性,平均寿命30d。每雌产卵量250粒左右,卵多散产于嫩枝或粗枝的隐面,卵期平均8d。幼虫5个龄期,完成发育平均历期37d,取食约160片柳叶。蛹期20d。7、8月份以第一代的幼虫危害较重。  相似文献   

4.
通过室内饲养结合野外定点观察,对西北槌缘叶蜂的形态特征、生物学特性进行研究.西北槌缘叶蜂在宁夏六盘山林区1 a发生1代,以老熟幼虫在落叶层或草丛中吐丝结茧、预蛹形式越冬.翌年5月上旬开始化蛹,5月中旬始见成虫,5月下旬为成虫羽化盛期.成虫羽化后需进行补充营养,成虫营孤雌生殖,产卵于针叶组织,产卵盛期为6月上旬.6月中旬幼虫大量孵出,啃食华北落叶松针叶,幼虫5龄.7月上旬大量停止取食,下树吐丝结茧越冬.  相似文献   

5.
稻水蝇在内蒙古东部地区年发生 4代 ,世代重叠 ,发育历期世代间存有极显著的差异 ,虫态间发育历期除幼虫与蛹外亦呈极显著差异 .成虫越冬 .4月下旬越冬成虫大量出现 .4月下旬见一代卵 ,5月 10日为一代幼虫盛发期 ,化蛹在 5月 2 5日始盛 ,一代成虫于 5月下旬可见 .第二代 5月下旬见卵 ,6月上旬至 7月上旬幼虫发生 ,6月中旬至 7月上旬化蛹 ,6月下旬至 7月中旬为二代成虫可见期 .第三、四代幼虫分别发生于 7月上旬及下旬 ,第四代成虫于 8月中旬羽化 ,8月下旬达到羽化高峰并越冬 .第 2代危害严重 ,发生数量极显著多于其它各代  相似文献   

6.
枇杷舟蛾是批杷的一种重要害虫.该虫在莆田一年发生3代.以蛹越冬.第一代成虫在8月出现,世代历期平均62.6天;第二代成虫出现在10月中下旬至11月上旬,世代历期平均65.1天;越冬代成虫翌年4月下旬至6月上旬出现,世代历期平均209.8天.卵期1~3天;幼虫5龄,历期22~45天;越冬代蛹期141~170天;每雌可产卵105~287粒;成虫寿命3~15天.  相似文献   

7.
戈壁琵甲(鞘翅目:拟步甲科)生物学特性的研究   总被引:2,自引:0,他引:2  
戈壁琵甲2年发生1代,世代不整齐,以成虫和不同龄期的幼虫越冬,成虫4月上旬至9月下旬产卵,卵期为8~12d.幼虫一般为12龄.幼虫期为1~1.5a.越冬幼虫于次年6月下旬至9月上旬化蛹.蛹前期为40~45d,蛹期为12~20d.羽化成虫后经280~300d性成熟,开始交配产卵,戈壁琵甲食性杂.不喜光.活动有明显的节律性.成虫具有利用防御腺进行自卫的特性,其防御腺分泌物可成为医学上的天然药物,该幼虫各项营养成分较高,是一种很有开发价值的昆虫资源。  相似文献   

8.
通过野外调查,观察记录食叶害虫绢粉蝶Aporia crataegi(Linnaeus)的生长发育过程和行为习性,明确绢粉蝶的形态及生物学特性.绢粉蝶在宁夏银川地区1 a发生1代,以2~3龄幼虫聚集在叶囊内越冬;3月下旬,越冬代幼虫开始出蛰活动;4月中下旬幼虫进入老熟期,在寄主枝干上或者杂草堆里化蛹,蛹期近14 d; 5月初开始羽化,成虫5月中旬开始产卵,下旬出现第一代幼虫,7月中旬后进入越夏.  相似文献   

9.
云南松梢木蠹象是鞘翅目、象虫科的一种蛀食云南松、华山松害虫。在盐源县一年发生一代,以幼虫在枝梢内越冬。3月上旬越冬后幼虫在受害枝梢内取食为害,4月中旬开始化蛹;4月下旬至5月上旬为成虫羽化始期,6月上旬为盛期,6月下旬交尾,7月上旬产卵,7月中旬幼虫开始孵出,7月下旬进入越冬状态。防治技术主要是4月下旬至6月下旬采用人工卫生伐除虫枝集中烧毁及掌握有利时机进行化学药剂防治。  相似文献   

10.
枸杞木虱的生物学特性及其防治   总被引:1,自引:0,他引:1  
枸杞木虱在西宁地区一年发生2代,以成虫在土缝及附近杂草枝杈处越冬.翌年3月下旬至4月上旬成虫开始活动,4月下旬在新发嫩叶上产卵.若虫孵化后营固定生活,取食芽梢汁液,导致新叶畸形,提早干枯落叶.在越冬代成虫发生期及第一代、第二代2~3龄若虫发生盛期用化学药剂进行防治,可有效地降低该虫的危害.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
19.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

20.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

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