中国大蓟马属一新种：缨翅目：蓟马科

本文中国大蓟马属Ｍｅｇａｌｕｒｏｔｈｒｉｐｓ１新种－灰褐大蓟马Ｍ．ｇｒｉｓｂｒｕｎｎｅｕｓ，模式标本保存于西北浓业大学昆虫博物馆。     

陕西太白山大蓟马属二新种（缨翅目：蓟马科）

记述中国大蓟马属Megalurothrips2新种,等大蓟马Megalurothrips equaletae sp.nov,和嵩坪大蓟马Megalurothrips haopingensis,sp.nov.,模式标本保存于西北农业大学昆虫博物馆。     

土壤含水量和土壤类型对豆大蓟马蛹期发育和羽化的影响

豆大蓟马Megalurothrips usitatus(Bagrall)是近年来严重制约海南豇豆生产的重要害虫。针对该蓟马在土壤中化蛹的习性,本文研究了在室内条件下不同土壤含水量和土壤类型对豆大蓟马化蛹的影响。结果表明,土壤含水量和土壤类型显著影响豆大蓟马蛹的发育历期和羽化率,土壤含水量为15%且土壤类型为砂壤土时,豆大蓟马的发育历期最短为3.62±0.15 d,羽化率最高为52.08%±0.07%,低含水量(5%)和高含水量(25%)均不利于豆大蓟马化蛹。土壤类型以砂壤土最适宜豆大蓟马化蛹,粘土最不适合豆大蓟马化蛹,其羽化率最低为19.17%±0.02%。     

中国新记录属--大蓟马属分类研究(缨翅目:管蓟马科)

报道中国新记录属大蓟马属Megathrips Targioni—Tozzetti及新记录种宽腹大蓟马Megathrips lativentris（Heeger,1852）,并记述1新种——黑角大蓟马Megathrips antennatus．sp．nov．。     

豆大蓟马对寄主植物及挥发性化合物的趋性

为明确不同寄主和不同信息化合物对豆大蓟马的行为影响,本文应用"Y"型嗅觉仪测定了豆大蓟马雌成虫对两种寄主植物花和不同浓度(v/v)下11种化合物的趋向性反应,结果表明:豆大蓟马对豇豆花、10-4烟酸乙酯、10-6烟酸乙酯、10-2橙花醇、10-2芳樟醇、10-6邻茴香醛和10-23-苯丙醛、10-43-苯丙醛具有极显著的趋向反应;对四季豆花和10-4橙花醇具有显著的趋向反应;10-4β-香茅醇、10-6β-香茅醇和10-6苯甲醛对豆大蓟马具有显著的驱避反应。不同浓度同一化合物对豆大蓟马的吸引作用也存在显著差异。实验结果可为进一步开发利用信息化合物田间防治豆大蓟马提供参考。     

普通大蓟马聚集信息素的分离和鉴定

【目的】普通大蓟马Megalurothrips usitatus是我国华南地区重要的豆科害虫,给我国豇豆种植产业带来巨大损失。开发利用基于聚集信息素的引诱剂是普通大蓟马的绿色防控措施之一,对于普通大蓟马生物防治具有重要意义。【方法】采用Y型嗅觉仪测定普通大蓟马雌雄成虫对其雌虫和雄虫气味源的嗅觉反应;用顶空固相微萃取法(head space solid-phase microextraction, HS-SPME)和溶液浸提法提取普通大蓟马雌雄成虫挥发物;应用气质联用仪(gas chromatography-mass spectrometry, GC-MS)对收集的气体挥发物和正己烷提取物进行活性成分分离鉴定;应用Y型嗅觉仪测定人工合成聚集信息素组分对雌雄成虫的引诱效果。【结果】行为学试验结果表明,普通大蓟马雄成虫气味源对其雌雄成虫均具有显著的引诱作用,而雌成虫气味源则没有。顶空固相微萃取法和溶液浸提法均可提取雄成虫挥发物主要组分,但顶空固相微萃取法获得的TIC图基线平稳,杂峰少,提取效果优于溶剂浸提法。GC-MS分析结果表明,普通大蓟马雄成虫挥发物中主要含有 1种化合物,为反式,反式-金合欢醇乙酸酯［(E,E)-farnesyl acetate］,该化合物在雌成虫挥发物中不存在。室内行为学实验结果表明,特定剂量的人工合成的(E,E)-farnesyl acetate对普通大蓟马雌雄成虫均具有显著的引诱作用。【结论】本研究证明了普通大蓟马雄成虫可以释放聚集信息素,并鉴定了其主要组分(E,E)-farnesyl acetate,为应用聚集信息素开展普通大蓟马的监测和诱杀提供了基础。     

普通大蓟马对寄主植物及其挥发物的行为反应

普通大蓟马Megalurothrips usitatus(Bagnall)是我国华南地区豆科植物上的重要害虫,并已对多种农药产生严重的抗药性,为减少化学农药的使用,探寻基于寄主植物挥发物的化学生态调控技术,针对不同寄主植物及其挥发性信息化合物对普通大蓟马的行为影响进行研究和探讨.本研究采用"Y"型嗅觉仪测定了普通大蓟马对豇豆花和四季豆花的选择行为,在此基础上再利用"Y"型嗅觉仪和四臂嗅觉仪测定了普通大蓟马对不同生理期及不同为害程度的豇豆花的选择行为,筛选该虫的嗜好寄主及其生理状态.分别以正己烷和甲醇作为溶剂,应用顶空动态吸附法和溶剂浸取法提取寄主植物挥发物,利用气相色谱-质谱联用仪(GC-MS)对其成分进行分析和鉴定.通过"Y"型嗅觉仪测定普通大蓟马对上述挥发物的不同浓度的标样及其混配物的行为反应,结果表明豇豆花对普通大蓟马的引诱活性显著高于四季豆花,后续试验进一步表明健康豇豆花对普通大蓟马的引诱效果好于花蕾、虫蕾和虫花.利用GC-MS从普通大蓟马嗜好寄主健康豇豆花中初步鉴定出42个挥发性信息化合物主要化学成分,购买标样对普通大蓟马进行不同浓度的行为活性测定,发现10-4β-石竹烯、10-2植物醇、10-6棕榈酸乙酯和10-6邻二甲苯具极显著的引诱作用,10-4罗勒烯、10-4亚油酸甲酯、10-4棕榈酸甲酯、10-4甲酯、10-62-甲基-3-羟基-4-吡喃酮具极显著的驱避作用,而棕榈酸乙酯在高浓度时表现出驱避作用,低浓度时表现出引诱作用.此外,当邻二甲苯和β-石竹烯、邻二甲苯和棕榈酸乙酯浓度为10-6时,其混配物对普通大蓟马表现出极显著的驱避作用,本试验尚未发现可增强引诱活性的配方.健康豇豆花为普通大蓟马的嗜好寄主,从其挥发性信息化合物中鉴定筛选出一批对普通大蓟马具显著引诱或驱避活性的化合物,为探明普通大蓟马对寄主植物的反应机制提供了信息基础,亦为今后研发高活性引诱剂或驱避剂提供理论基础.     

普通大蓟马对不同颜色的趋性及日节律调查

【目的】探明普通大蓟马Megalurothrips usittus(Bagrall)的嗜好颜色及其田间日活动节律。【方法】分别在室内和田间对10种不同颜色色板(白色、黑色、灰色、红色、绿色、黄色、蓝色、紫色、粉色和浅蓝色,佳多~?进行了非选择性试验,并通过将RGB颜色值转换为虚拟波长进行最嗜颜色量化非选择性试验,然后选择引诱效果最好的色板对普通大蓟马进行日活动节律调查。【结果】室内和田间选择试验表明蓝色对普通大蓟马的吸引率显著高于其它颜色,其次是浅蓝色和紫色;由RGB颜色值转换虚拟波长得到普通大蓟马最嗜颜色对应的波长为470 n(RGB值为0,193,255,蓝色);通过蓝板调察普通大蓟马日活动节律发现,普通大蓟马成虫种群活动节律明显,活动规律呈单峰型,活动最高峰为8:00-10:00,夜间(20:00—次日6:00)几乎不活动。【结论】研究结果为基于颜色趋性的普通大蓟马田间监测和综合治理提供了理论基础和科学依据。     

马立克氏病病毒强毒GA株基因组BamH Ⅰ-L片段的序列分析

马立克氏病病毒（Ｍａｒｅｋ’ｓｄｉｓｅａｓｅｖｉｒｕｓ,ＭＤＶ）是一种能诱导鸡淋巴组织增生或淋巴肿瘤的细胞结合性疱疹病毒,由此而引起的马立克氏病（Ｍａｒｅｋ’ｓｄｉｓｅａｓｅ,ＭＤ）也是迄今为止唯一可以利用疫苗进行有效控制的肿瘤性疾病。鉴于此,作为研...     

南亚大眼长蝽和西沙大眼长蝽的捕食功能研究

【目的】研究海南本土长蝽类天敌昆虫对三亚瓜菜上主要害虫的捕食潜力,为天敌昆虫的田间应用提供基础依据。【方法】在室内不同温度条件下,当南亚大眼长蝽Geocoris ochropterus Fieber和西沙大眼长蝽Geocoris xishaensis与不同害虫共存时,统计2种长蝽分别对普通大蓟马Megalurothrips usitatus Bagrall、豆蚜Aphis craccivora Koch、叶蝉Cicadellidae和露尾甲Haptonchus luteolus的取食偏好性,评估2种天敌对主要猎物普通大蓟马的捕食能力。【结果】与蚜虫、叶蝉和露尾甲相比,2种长蝽对普通大蓟马具有较强的捕食偏好性,且对普通大蓟马成虫捕食偏好性高于蓟马若虫。在不同温度的条件下比较2种长蝽对普通大蓟马的捕食量,结果表明28℃是2种长蝽的最佳捕食温度,南亚大眼长蝽雌虫、雄虫、4-5龄若虫和2-3龄若虫对普通大蓟马的最高日捕食量分别为（49.18±8.71）、（47.23±7.81）、（43.60±10.29）和（30.10±4.65）头/d;西沙大眼长蝽雌虫、雄虫、4-5龄若虫和2-3龄若虫对普通大蓟马的日捕食量分别达到（33.37±3.89）、（32.65±5.12）、（23.87±2.37）和（27.36±3.19）头/d。【结论】南亚大眼长蝽和西沙大眼长蝽成虫和若虫对瓜菜上主要害虫均具有一定的捕食潜力,无论成虫还是若虫对普通大蓟马具有最高的捕食倾向性,且雌成虫对普通大蓟马成虫的捕食能力最强。研究结果为将来2种海南本地长蝽的田间防控应用奠定基础。     

Developing Methods for Testing Host Specificity of Phymastichus coffea LaSalle (Hym.: Tetrastichinae), a Potential Biological Control Agent of Hypothenemus hampei (Ferrari) (Col.: Scolytidae) in Colombia

In line with the United Nations Food and Agriculture Organization Code of Conduct for the import and release of biological control agents, and taking into consideration the recommendations in the draft IUCN (International Union for Conservation of Nature and Natural Resources) Guidelines for the Prevention of Biodiversity Loss Due to Biological Invasion, a procedure was developed to assess the host range of Phymastichus coffea , an endoparasitoid of coffee berry borer, Hypothenemus hampei . Host specificity was tested by exposing a Kenyan biotype of P. coffea to a selection of Scolytidae under quarantine conditions. The results demonstrated that P. coffea can be considered as oligophagous, attacking and developing on other species of the genus of the target borer. In no-choice tests, three species, H. obscurus , H. seriatus and Araptus sp. yielded parasitism. The risk of attack to potential alternative hosts if P. coffea were to be released as a potential biological control agent of coffee berry borer in Colombia is discussed. A quarantine procedure was developed for the importation of P. coffea to Colombia to deal with specific problems of hyperparasitoids and fungal contamination.     

A new genus of filicalean fern from the Lower Permian of China

Recent investigation on the Cathaysian flora of the Lower Permian Taiyuan Formation in Hebei Province, North China has led to the discovery of a new type of fern, Rastropteris pingquanensis gen. et sp. nov. Preserved as a permineralization, the stem, with a mantle of petiole bases and roots, shows a unique combination of anatomical characters. The vascular strand consists of a solid protostele with uniformly elongated tracheids and mesarch maturation of the xylem. In transverse section, the configuration of leaf trace xylem changes from reniform endarch to a tangentially elongated strand adaxially recurved at each end with several adaxial ridges. Stem and petiole cortex contains abundant sclerotic tissue with an interstitial tissue developed within the mantle of petiole bases and roots. A reinvestigation of Grammatopteris rigollotii , from the Permian of France, the type species of the genus allows interpretation of the latter as closer to Rastropteris than any other fern. Both taxa are provisionally reported to an incertae sedis group of filicalean ferns possibly involved in the origin of Osmundaceae.     

Next‐generation DNA barcoding: using next‐generation sequencing to enhance and accelerate DNA barcode capture from single specimens

DNA barcoding is an efficient method to identify specimens and to detect undescribed/cryptic species. Sanger sequencing of individual specimens is the standard approach in generating large‐scale DNA barcode libraries and identifying unknowns. However, the Sanger sequencing technology is, in some respects, inferior to next‐generation sequencers, which are capable of producing millions of sequence reads simultaneously. Additionally, direct Sanger sequencing of DNA barcode amplicons, as practiced in most DNA barcoding procedures, is hampered by the need for relatively high‐target amplicon yield, coamplification of nuclear mitochondrial pseudogenes, confusion with sequences from intracellular endosymbiotic bacteria (e.g. Wolbachia) and instances of intraindividual variability (i.e. heteroplasmy). Any of these situations can lead to failed Sanger sequencing attempts or ambiguity of the generated DNA barcodes. Here, we demonstrate the potential application of next‐generation sequencing platforms for parallel acquisition of DNA barcode sequences from hundreds of specimens simultaneously. To facilitate retrieval of sequences obtained from individual specimens, we tag individual specimens during PCR amplification using unique 10‐mer oligonucleotides attached to DNA barcoding PCR primers. We employ 454 pyrosequencing to recover full‐length DNA barcodes of 190 specimens using 12.5% capacity of a 454 sequencing run (i.e. two lanes of a 16 lane run). We obtained an average of 143 sequence reads for each individual specimen. The sequences produced are full‐length DNA barcodes for all but one of the included specimens. In a subset of samples, we also detected Wolbachia, nontarget species, and heteroplasmic sequences. Next‐generation sequencing is of great value because of its protocol simplicity, greatly reduced cost per barcode read, faster throughout and added information content.     

Modelling the patterns of dispersion of length at age in teleost fishes

The patterns of dispersion of length at age were analysed in 142 samples representing 115 stocks, 72 species and seven orders of teleost fishes. The coefficients of variation i.e. the ratios of the standard deviations to the mean lengths, declined with age in 85 samples, did not vary significantly with age in 50 samples and increased with age in seven samples. A rapid exponential decline in the coefficients of variation of length with age was a dominant characteristic of most short-lived stocks. Conversely, in most long-lived stocks, the coefficients of variation of length remained relatively constant, declined gradually, or increased slightly with age. It is proposed that the patterns of dispersion of length at age can be modelled empirically as a function of longevity. The probable sources of the observed patterns, including the intrinsic variability of life-history parameters between individuals and the impact of social interactions, are discussed.     

A review of studies on Pichavaram mangrove, southeast India

We studied a tropical mangrove ecosystem, situated at Pichavaram, southeast India. We found 13 species of mangrove trees, with Avicennia marinaand Rhizophora species predominant, besides 73 spp. of other plants, 52 spp. of bacteria, 23 spp. of fungi, 82 spp. of phytoplankton, 22 spp. of seaweeds, 3 spp. of seagrass, 95 spp. of zooplankton, 40 spp. of meiobenthos, 52 spp. of macrobenthos, 177 spp. of fish and 200 spp. of birds. The bacteria performed activities like photosynthesis, methanogenesis, magnetic behaviour, human pathogens and production of antibiotics and enzymes (arysulphatase, L-glutaminase, chitinase, L-asparaginase, cellulase, protease, phosphatase). The microzooplankton included tintinnids, rotifers, nauplius stages of copepods and veliger larvae of molluscs, with a predominance of tintinnids. Tintinopsis spp. alone accounted for 90% of abundance. The macrozooplankton consisted of 95% of copepods and coelenterates. The meiofauna was rich with nematodes (50–70% of the component), followed by foramifera. The macrofauna included polychaetes, bivalves, gastropods, tanaids, isopods, amphipods, cirripedes, crabs, hermit crabs and shrimps. The mangrove harboured a large number of juvenile fishes, especially during summer and post-monsoon. The water was fertile and productive in having several fold-higher levels of nutrients, microbes, plankton and other biological resources, than the adjoining estuarine, backwater and neritic environments. The gross primary production was 8 g cm^-3 d^-1; about 21% of which was contributed by phytoplankton of 5–10 m size. Unfortunately, 90% of the mangrove cover in the study area was degraded. Possible factors that cause degradation of the ecosystem are detailed and remedial measures suggested. Techniques for regeneration of the degraded areas are proposed.     

Potential denitrification in submerged natural and impacted sediments of Lake Batata,an Amazonian lake

Lake Batata is one of many clear water lakes located on the floodplain of the Trombetas River in the northern Brazilian Amazon. Lake Batata is distinctly different from other lakes of this region because, for a period of 10 years, its waters received tremendous amounts of aluminum ore tailings from a bauxite mining operation. Approximately 30% of the sediments of the upper basin of the 2100 hectare lake were covered by tailings before dumping was curtailed. The goal of this research was to identify factors controlling denitrification in the natural and impacted sediments of Lake Batata. Rates of denitrification in sediments were estimated in the laboratory by the acetylene blockage method. Denitrification was measured under four conditions: without amendment; amended with glucose; amended with nitrate; and amended with glucose and nitrate. Denitrification was observed only in assays amended with nitrate suggesting that availability of nitrate is a principle factor for controlling denitrification in the sediments of Lake Batata. Effects of nitrate amendments are most pronounced when the water level is low, i.e. during the hydroperiods of draw-down and low-water.     

Multiple Parasitism by Cotesia sesamiae and Cotesia flavipes (Hymenoptera: Braconidae) on Busseola fusca (Lepidoptera: Noctuidae)

Busseola fusca (Fuller) is one of the most important pest of cereals in sub-Saharan Africa. Cotesia sesamiae (Cameron) is the predominant parasitoid attacking B. fusca larvae in many parts of Africa. An exotic parasitoid, Cotesia flavipes Cameron, was introduced into Kenya in 1993 for the control of Chilo partellus (Swinhoe). Laboratory studies indicated that although C. flavipes would search for, and attack B. fusca , it was not able to complete its development in this host. The aim of the present study was to investigate the outcome of multiple parasitism of B. fusca by the two Cotesia species. The study showed that when both parasitoid species stung a B. fusca larva at the same time, both parasitoids emerged from more than half of the host larvae, C. flavipes alone emerged from 17%, and C. sesamiae alone emerged from 9%. When the larvae were parasitized by C. sesamiae first, and then 2 h later by C. flavipes , and vice versa, most of the progeny were C. flavipes . However, when B. fusca larvae were stung by C. sesamiae three days before oviposition by C. flavipes , significantly more C. sesamiae emerged from the larvae. When C. flavipes oviposited first, no larvae produced C. flavipes only. The interaction of parasitoids and the host immune system, and the implications of these results for the biological control of stem borers in East Africa are discussed.     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.