Lower Cambrian yolk-pyramid embryos from Southern Shaanxi, China

TheCambrianexplosioniswidelyacceptedasthesuddenappearanceofnumerousbilateriananimalphylaatornearthebeginningofCambriantime[1,2 ] .The 5 30 million year oldMaotianshanShalefaunacontainstheoldestgoodwhole bodyfossilsofbilateri ans,documentinganincreasingnumberofpresent dayanimalphyla[3,4 ] orsubphyla[5] (evenincludingvertebrates[6～ 8] aswell)knownfromLowerCambri an .ThebeginningoftheCambrianperiodisdatedat5 43millionyearsago ,whenthefirstlargeandelabo ratefossilburrowstogetherwiththemicrosco…     

Possible developmental mechanisms underlying the origin of the crown lineages of arthropods

The extraordinarily preserved, diverse arthropod fauna from the Lower Cambrian Maotianshan shale, central Yunnan (southwest China), represents different evolutionary stages stepping from stem lineages towards crown arthropods (also called euarthropods), which makes this fauna extremely significant for discussion of the origin and early diversification of the arthropods. Anatomical analyses of the Maotianshan shale arthropods strongly indicate that     

A venomous arthropod in the Early Cambrian Sea

A number of recently evolved animals possess poison glands for feeding and/or defense.However,examples of such animals are rare in the fossil record.We report a fossil arthropod Isoxys curvirostratus from the Early Cambrian Chengjiang biota of China.This species is regarded as the oldest known venomous arthropod based on the presence of venomous glands in its head region.The adult animal is 2-5 cm long and the body is covered entirely with a carapace.The presence of large stalk eyes and a pair of stout grasping appendages with a terminal spine suggest it was raptorial.Interestingly,the two pear-shaped,three-dimensionally preserved objects that are present in the head region and at the base of the grasping appendages closely resemble the venom glands of some living arthropods in size,shape,and position.These features indicate that the presence of venomous predators could date back 520 million years.Furthermore,our observations suggest that the feeding strategies and organs adapted for this purpose had already reached a high level of diversity and anatomical sophistication in the Early Cambrian ecosystems.     

板栗园节肢动物群落物种多样性研究

2001-2004 年采用系统调查与随机调查相结合的方法在重庆合川对板栗园节肢动物群落的物种多样性进行了研究.研究中共记录节肢动物12 目63 科136 种,其中鉴定到种的有120 种,占88%;制作了136 个种的名录;分析了节肢动物群落的构成,讨论了主要种的生态和经济意义;此外,分析了板栗园树冠主要类群的季节数量消长动态,整个群落和害虫及天敌亚群落个体数量和Shannon-Wiener 生物多样性指数的季节动态.本研究建立了板栗园节肢动物群落生物多样性的信息框架,对了解板栗园生态系统和板栗园害虫的综合治理具有一定科学和应用价值.     

淮南土壤甲螨资源调查研究

为了解淮南地区甲螨种群的分布 ,以合理应用该地区的甲螨生物资源。采用野外选点现场取土样 ,应用 Tullgren装置分离甲螨 ,并将所获甲螨分科列出名录。发现获取的甲螨种类相当复杂 ,现已鉴定的甲螨 33种 ,隶属 2 4科。因此 ,淮南地区土壤甲螨种类繁多 ,具有进一步研究和开发、应用价值     

稻田生态系统中杂草地捕食性节肢动物群落研究

采用吸虫器法采样，对稻田生态系统中杂草地捕食性节肢动物天敌群落物种多样性、结构动态等进行了系统的研究。在杂草地生境中采集到73种捕食性节肢动物，其中55种为捕食性蜘蛛，18种为捕食性昆虫。在冬春闲期，杂草地生境的捕食性节肢动物物种多样性和单位面积内的个体数量较高。水稻移栽后，杂草地中的捕食性节肢动物种群迁进稻田，为稻田提供天敌移居者，杂草地生境中的捕食性天敌物种数减少，单位面积内的个体数量降低；水稻成熟后、夏闲期始及冬闲期始，杂草地接纳从稻田中迁出的天敌种群，捕食性天敌物种数和单位面积内的个体数量呈上升趋势。杂草地为保护稻田捕食性天敌，提供了一个良好的庇难所。     

稻田与非稻田生境越冬节肢动物群落调查与分析

2008年11月至2009年3月,对清新县双季稻田的冬闲田WF、田埂FR、周围杂草WH以及黑麦草田LL等4种不同生境下的节肢动物越冬群落进行系统调查。结果如下:鉴定出包括昆虫纲8目22科和蛛形纲1目6科共33种节肢动物。其中,植食性昆虫16种,捕食性昆虫4种,寄生性昆虫3种,中性昆虫3种,蜘蛛类7种。闲田和杂草均以蜘蛛类为主要优势种类,而田埂和黑麦草田分别以半翅目和双翅目昆虫为最优势类群。Shannon-Wiener多样性指数(H)和Pielou均匀性指数(J)以田埂的最高,黑麦草田最低;优势度指数(C)以黑麦草田高,田埂最低。杂草地与黑麦草田Jaccard相似性指数(q)最高,而冬闲田与田埂的相似性指数最低。     

珠海荔枝园节肢动物群落动态及其主要益害虫相关性研究

于2010—2011年系统调查了珠海凤凰山区荔枝园内节肢动物群落,分析了群落的结构组成、时空动态及主要益害虫相互作用关系,结果如下:1)共采集到节肢动物2个纲、16个目、48个科、79个种,其中害虫35种,捕食性节肢动物29种,中性昆虫9种,寄生性节肢动物6种.荔枝园节肢动物群落较丰富,益害虫优势种明显.2)随着温度变化,群落总体及个各类群的物种在5—11月份丰富度最大.3)害虫优势种为荔枝蝽(Tessaratoma papillosa)与荔枝瘿螨(Aceria litchii).其主要天敌为锥腹肖蛸(Tetragnatha maxillosa)、草间小黑蛛(Erigonidium graminicolum)和异色瓢虫(Leis axyridis).     

一种节肢动物模板DNA的快速提取方法

简要介绍一种高效、快速提取节肢动物模板DNA的方法,提取的DNA无污染物产生,完全能满足 RAPD等研究的需要.     

Investigation of Volatile Iridoid Terpenes in Nepeta cataria L. (Catnip) Genotypes

Catnip (Nepeta cataria L.) is of scientific interest largely due to the production of nepetalactones, volatile iridoid terpenes with strong arthropod repellent activity. However, the plant can also produce other bioactive volatile iridoids, such as nepetalic acid (NA), nepetalactam (NT) and dihydronepetalactone (DHNL) that have not been studied extensively. Germplasm studies on plants that can produce such compounds are scarce. The present study evaluated the chemical diversity of catnip genotypes with a focus on NA, NT and DHNL. A total of 34 genotypes were harvested at different times over two years. The ethanolic extract of the plants was screened for iridoids by ultra-high-performance liquid chromatography/triple quadrupole mass spectrometry. CR9 × CR3 genotype had the highest value for biomass yield, while cultivar CR9 had the highest value for accumulated NA. Genotype UK.2 had the highest value for accumulated NT yield and CR5 had the highest value for accumulated DHNL. Overall, patented cultivars and elite selections performed better than other less studied genotypes. Harvest time influenced the accumulation of secondary metabolites differentially for the genotypes. This is the first germplasm study with a focus on these iridoid compounds, yet more studies are necessary as genotype characterization is essential for breeding and standardization of products for industry.