《昆虫知识》2009年第46卷第3期要目预告

科技前沿 昆虫葡萄糖氧化酶及其功能…胡永红等 蜜蜂及熊蜂微孢子虫rRNA基因研究进展…陈文锋等     

Calcofluor White M2R与Sytox Green双重染色法鉴别蜜蜂微孢子虫

东方蜜蜂微孢子虫(Nosema ceranae)是一种广泛寄生于东方蜜蜂Apis cerana,西方蜜蜂Apis mellifera和熊蜂Bombus Latreille上的寄生虫,对蜜蜂和熊蜂的危害较大,进而影响养蜂业的发展。本实验采用荧光染色试剂Calcofluor White M2R与核酸染料Sytox Green双重染法来鉴别蜜蜂或熊蜂体内的N.ceranae及孢子的存活状态。结果得出,在荧光显微镜下可见死孢子被染上黄绿色荧光,活的呈现蓝白色荧光,而寄主细胞、细菌、病毒等不被染色。这是一种快速有效鉴别N.ceranae及其死活的方法,从而判定蜜蜂或熊蜂体内的微孢子虫在是否具有侵染活性,对微孢子虫的研究及药物防治具有重要作用。     

微孢子虫的进化起源与系统分类现状

系统回顾了微孢子虫起源进化的研究进展及其系统分类现状。近30年来,一些依据SSU r DNA序列、翻译延伸因子1α序列、直系同源蛋白基因树及真菌蛋白质组生命树等的研究支持微孢子虫起源于原生生物。但同时大量的单基因或多基因系统发育研究又支持微孢子虫起源于真菌。最近一系列独立的系统基因组学研究结果,加上在罗兹菌门中发现了介于真菌和微孢子虫中间类型的近微孢虫菌属(Paramicrosporidium)、线孢虫菌属(Mitosporidium)和噬核菌属(Nucleophaga),进一步支持微孢子虫起源于罗兹菌门的噬核菌属谱系。     

东方蜜蜂微孢子虫侵染意大利蜜蜂工蜂过程中nce-miR-10660及其靶基因表达谱

【目的】本研究旨在为探究nce-miR-10660调控东方蜜蜂微孢子虫Nosema ceranae侵染的作用机制提供理论和实验依据。【方法】采用Stem-loop RT-PCR对前期鉴定到的东方蜜蜂微孢子虫nce-miR-10660进行表达验证，再通过Sanger测序验证nce-miR-10660的序列。利用相关生物信息学软件预测和分析nce-miR-10660的靶基因。通过RT-qPCR检测nce-miR-10660及其靶基因在东方蜜蜂微孢子虫侵染意大利蜜蜂Apis mellifera ligustica工蜂过程中中肠中的表达谱。【结果】Stem-loop RT-PCR和Sanger测序结果分别证实了nce-miR-10660在东方蜜蜂微孢子虫孢子中的表达和真实存在。靶向预测结果显示nce-miR-10660共靶向RRDRP和RCDP 42等9个基因；分别有2和6个靶基因可被分别注释到KEGG数据库中的4条通路和GO数据库中的23个条目。RT-qPCR结果显示，相较于东方蜜蜂微孢子虫侵染后1 d时意大利蜜蜂工蜂中肠中nce-miR-10660的表达量，东方蜜蜂微孢子虫侵染后2 d时意...     

蜜蜂微孢子虫在中国的自然种系构成初探

蜜蜂微孢子虫(Nosema apis及Nosema ceranae)是微孢子虫的典型代表之一,由它寄生蜜蜂所产生的疾病,称为蜜蜂微孢子虫病。通过目前国际上普遍使用的克隆16srRNA基因(16srDNA)的片段并测序的方法来进行蜜蜂微孢子虫在我国主要养蜂地区的分布情况。结果表明,在我国主要养蜂地区,造成大量西方蜜蜂患蜜蜂微孢子虫病的是东方蜜蜂微孢子虫Nosema ceranae,至今为止未发现过去我们广泛认定的西方蜜蜂微孢子虫Nosema apis。     

一株家蚕异型微孢子虫感染特征和分类地位

【背景】家蚕微粒子病是一种对蚕业生产危害巨大的蚕病,该病病原是蚕种生产唯一检疫对象,而家蚕病原性微孢子虫种类多、来源复杂,给蚕种生产微粒子病的防控增加了难度。【目的】研究一株从蚕种检疫样品中分离的微孢子虫(命名为GXM15)的致病性和分类地位,鉴定并分析其来源,完善家蚕病原性微孢子虫分类和数据库,为蚕种生产控制家蚕微粒子病提供参考依据。【方法】采用生物试验方法测定GXM15微孢子虫对家蚕的半数感染浓度(IC50)和胚种传染率;显微镜观察GXM15微孢子虫孢子形态,利用透射电子显微镜观察GXM15微孢子虫的超微结构;采用PCR扩增、T克隆和测序获得GXM15微孢子虫的SSU rRNA基因和ITS片段DNA序列,并利用MEGA 5.0和DNAstar软件构建GXM15微孢子虫的系统发育树和遗传距离分析。【结果】GXM15微孢子虫对家蚕的IC50为8.29×104个/mL,是家蚕微孢子虫(Nosema bombycis,Nb)的2.28倍;GXM15微孢子虫对家蚕的胚种传染率为3.6%,明显低于Nb;GXM15微孢子虫形态呈短卵圆形,大小为(2.05±0.20)× (3.25±0.30) μm,GXM15微孢子虫体积是Nb微孢子虫的2.19倍;GXM15微孢子虫超微结构具双核,极丝13圈,极丝倾斜角约45°,符合Nosema属的特征;GXM15微孢子虫SSU rRNA基因在系统发育树中位于Nosema属分支中,遗传距离分析表明GXM15微孢子虫与Nb同属异种,是一株新微孢子虫。【结论】GXM15微孢子虫是一株家蚕病原性微孢子虫,根据GXM15微孢子虫致病性和分类地位研究,可以为蚕种生产防控家蚕微粒子病提供参考依据。     

微孢子虫归类于真菌的评论

微孢子虫是一类专营寄生生活、无线粒体的单细胞真核生物,在分类学上一直归类于原生生物界,原生动物亚界。但最近对微孢子虫分子进化和系统发育的研究认为微孢子虫与真菌具有很近的亲缘关系,美国生物技术信息中心(NCBI)2002年将微孢子虫归类于真菌。本文予以综述和评论。     

东方蜜蜂微孢子虫N6-腺苷特异性甲基化转移酶基因的克隆、分子特性及表达模式北大核心

【目的】东方蜜蜂微孢子虫(Nosme ceranae)专性侵染成年蜜蜂导致微孢子虫病,给养蜂生产造成很大损失。目前,东方蜜蜂微孢子虫的N6-腺苷特异性甲基化转移酶(N6-adenine-specific methyltransferase,N6AMT)基因NcN6AMT的研究仍然缺失。本研究对NcN6AMT的编码序列(coding sequence,CDS)区进行克隆,并解析NcN6AMT蛋白的理化性质和分子特性,进而测定东方蜜蜂微孢子虫侵染意大利蜜蜂(Apis mellifera ligustica)和中华蜜蜂(Apis cerana cerana)工蜂过程中NcN6AMT的相对表达量,以期丰富NcN6AMT的信息,并为探究东方蜜蜂微孢子虫侵染过程NcN6AMT的功能及表观调控机制提供基础。【方法】采用Protparam和ProtScale软件对NcN6AMT进行等电点和亲水性分析。通过SignalP 5.0、NetPhos 3.1、TMHMM-2.0、SOPMA和SWISS-MODEL等软件分别预测NcN6AMT的信号肽、磷酸化位点、跨膜结构域、二级结构和三级结构。使用WoLF PSORT II软件预测NcN6AMT的亚细胞定位。根据N6AMT氨基酸序列,通过TBtools软件对智人(Homo sapiens)、小鼠(Mus musculus)、褐飞虱(Nilaparvata lugens)、兔脑炎微孢子虫(Encephalitozoon cuniculi)、肠脑炎微孢子虫(Encephalitozoon intestinalis ATCC 50506)、蚱蜢脑炎微孢子虫(Encephalitozoon romaleae SJ-2008)、美洲思普雷格孢虫(Spraguea lophii 42_110)、家蚕微孢子虫(Nosema bombycis CQ1)、隐生菱形藻(Nitzschia inconspicua)和东方蜜蜂微孢子虫(Nosema ceranae)的N6AMT进行结构域预测和分析。利用MEME软件和MEGA 11.0软件进行东方蜜蜂微孢子虫和其他物种N6AMT的保守基序预测及进化树构建。采用实时荧光定量聚合酶链式反应(real-time fluorescence quantitative polymerase chain reaction,RT-qPCR)检测NcN6AMT在东方蜜蜂微孢子虫侵染意大利蜜蜂和中华蜜蜂工蜂过程的相对表达量。【结果】通过PCR扩增出大小约500 bp的目的片段,克隆测序结果显示其与GenBank数据库收录的预测序列一致;NcN6AMT蛋白的分子量约为18.7 kDa,分子式为C845H1374N214O249S6,理论等电点为5.88,脂溶系数是119.76,不稳定系数为37.47,平均亲水系数为0.025,含166个氨基酸和15个磷酸化位点,不含典型的跨膜结构域和信号肽,可同时定位于细胞质、线粒体、细胞核和液泡膜;NcN6AMT含1个甲基转移酶小结构域(methyltransferase small domain,MTS),该结构域同样存在于家蚕微孢子虫和兔脑炎微孢子虫等8个其他物种的N6AMT;在东方蜜蜂微孢子虫、兔脑炎微孢子虫、肠脑炎微孢子虫和蚱蜢脑炎微孢子虫的N6AMT中均预测到5个相同的保守基序;NcN6AMT与家蚕微孢子虫、肠脑炎微孢子虫、兔脑炎微孢子虫和蚱蜢脑炎微孢子虫的N6AMT序列一致性达到70.92%;东方蜜蜂微孢子虫和家蚕微孢子虫的N6AMT在系统进化树上聚为一支;东方蜜蜂微孢子虫接种后1–4 d,NcN6AMT在意大利蜜蜂和中华蜜蜂工蜂中肠内均呈现先上升后下降的表达趋势。【结论】成功克隆到NcN6AMT基因的CDS区,明确了NcN6AMT蛋白的理化性质和分子特性,并揭示东方蜜蜂微孢子虫和家蚕微孢子虫的N6AMT蛋白具有较高的保守性,NcN6AMT在东方蜜蜂微孢子虫侵染意大利蜜蜂和中华蜜蜂工蜂的第一个增殖周期(1–4 dpi)内动态表达且均呈上升-下降的表达模式。     

东方蜜蜂微孢子虫N6-腺苷特异性甲基化转移酶基因的克隆、分子特性及表达模式

【目的】东方蜜蜂微孢子虫(Nosme ceranae)专性侵染成年蜜蜂导致微孢子虫病,给养蜂生产造成很大损失。目前,东方蜜蜂微孢子虫的N6-腺苷特异性甲基化转移酶(N6-adenine-specific methyltransferase,N6AMT)基因NcN6AMT的研究仍然缺失。本研究对NcN6AMT的编码序列(coding sequence,CDS)区进行克隆,并解析NcN6AMT蛋白的理化性质和分子特性,进而测定东方蜜蜂微孢子虫侵染意大利蜜蜂(Apis mellifera ligustica)和中华蜜蜂(Apis cerana cerana)工蜂过程中NcN6AMT的相对表达量,以期丰富NcN6AMT的信息,并为探究东方蜜蜂微孢子虫侵染过程NcN6AMT的功能及表观调控机制提供基础。【方法】采用Protparam和ProtScale软件对NcN6AMT进行等电点和亲水性分析。通过SignalP 5.0、NetPhos 3.1、TMHMM-2.0、SOPMA和SWISS-MODEL等软件分别预测NcN6AMT的信号肽、磷酸化位点、跨膜结构域、二级结构和三级结构。使用WoLF PSORT II软件预测NcN6AMT的亚细胞定位。根据N6AMT氨基酸序列,通过TBtools软件对智人(Homo sapiens)、小鼠(Mus musculus)、褐飞虱(Nilaparvata lugens)、兔脑炎微孢子虫(Encephalitozoon cuniculi)、肠脑炎微孢子虫(Encephalitozoon intestinalis ATCC 50506)、蚱蜢脑炎微孢子虫(Encephalitozoon romaleae SJ-2008)、美洲思普雷格孢虫(Spraguea lophii 42_110)、家蚕微孢子虫(Nosema bombycis CQ1)、隐生菱形藻(Nitzschia inconspicua)和东方蜜蜂微孢子虫(Nosema ceranae)的N6AMT进行结构域预测和分析。利用MEME软件和MEGA 11.0软件进行东方蜜蜂微孢子虫和其他物种N6AMT的保守基序预测及进化树构建。采用实时荧光定量聚合酶链式反应(real-time fluorescence quantitative polymerase chain reaction,RT-qPCR)检测NcN6AMT在东方蜜蜂微孢子虫侵染意大利蜜蜂和中华蜜蜂工蜂过程的相对表达量。【结果】通过PCR扩增出大小约500 bp的目的片段,克隆测序结果显示其与GenBank数据库收录的预测序列一致;NcN6AMT蛋白的分子量约为18.7 kDa,分子式为C845H1374N214O249S6,理论等电点为5.88,脂溶系数是119.76,不稳定系数为37.47,平均亲水系数为0.025,含166个氨基酸和15个磷酸化位点,不含典型的跨膜结构域和信号肽,可同时定位于细胞质、线粒体、细胞核和液泡膜;NcN6AMT含1个甲基转移酶小结构域(methyltransferase small domain,MTS),该结构域同样存在于家蚕微孢子虫和兔脑炎微孢子虫等8个其他物种的N6AMT;在东方蜜蜂微孢子虫、兔脑炎微孢子虫、肠脑炎微孢子虫和蚱蜢脑炎微孢子虫的N6AMT中均预测到5个相同的保守基序;NcN6AMT与家蚕微孢子虫、肠脑炎微孢子虫、兔脑炎微孢子虫和蚱蜢脑炎微孢子虫的N6AMT序列一致性达到70.92%;东方蜜蜂微孢子虫和家蚕微孢子虫的N6AMT在系统进化树上聚为一支;东方蜜蜂微孢子虫接种后1–4 d,NcN6AMT在意大利蜜蜂和中华蜜蜂工蜂中肠内均呈现先上升后下降的表达趋势。【结论】成功克隆到NcN6AMT基因的CDS区,明确了NcN6AMT蛋白的理化性质和分子特性,并揭示东方蜜蜂微孢子虫和家蚕微孢子虫的N6AMT蛋白具有较高的保守性,NcN6AMT在东方蜜蜂微孢子虫侵染意大利蜜蜂和中华蜜蜂工蜂的第一个增殖周期(1–4 dpi)内动态表达且均呈上升-下降的表达模式。     

柞蚕微孢子虫Nosema pernyi微管蛋白基因的克隆及系统发育分析

【目的】柞蚕微粒子病的病原为柞蚕微孢子虫Nosemapernyi,为解明柞蚕微孢子虫微管蛋白基因的序列信息,明确柞蚕微孢子虫的系统分类学地位。【方法】采用RT-.PCR、3′RACE(Rapid amplification ofcDNAends)等技术克隆得到了柞蚕微孢子虫的α、β和y-微管蛋白基因,并利用α、β-微管蛋白序列,分别采用NJ、ML法构建进化树。【结果】将克隆得到的基因序列提交NCBI(GenBank登录号:KF154086、KF023271、KF740389)。构建的系统发育树显示,微孢子虫类以一个独立群位于真菌群体中,与真菌的虫霉门关系较近,且与担子菌、球囊菌、壶菌、接合菌及部分子囊菌互为姐妹群。从部分微孢子虫的系统发育分析结果可以看出,20种微孢子虫分为2个分支,柞蚕微孢子虫与其他Nosema属聚为一类。【结论】本研究克隆得到了柞蚕微孢子虫α、β和y-微管蛋白基因,系统发育分析为更进一步了解柞蚕微孢子虫奠定了基础。     

Pollination efficiency and foraging behaviour of honey bees and non‐Apis bees to sweet cherry

1. Crop pollination generally increases with pollinator diversity and wild pollinator visitation. To optimize crop pollination, it is necessary to investigate the pollination contribution of different pollinator species. In the present study, we examined this contribution of honey bees and non‐Apis bees (bumble bees, mason bees and other solitary bees) in sweet cherry.
2. We assessed the pollination efficiency (fruit set of flowers receiving only one visit) and foraging behaviour (flower visitation rate, probability of tree change, probability of row change and contact with the stigma) of honey bees and different types of non‐Apis bees.
3. Single visit pollination efficiency on sweet cherry was higher for both mason bees and solitary bees compared with bumble bees and honey bees. The different measures of foraging behaviour were variable among non‐Apis bees and honey bees. Adding to their high single visit efficiency, mason bees also visited significantly more flower per minute, and they had a high probability of tree change and a high probability to contact the stigma.
4. The results of the present study highlight the higher pollination performance of solitary bees and especially mason bees compared with bumble bees and honey bees. Management to support species with high pollination efficiency and effective foraging behaviour will promote crop pollination.

     

Bacterium (Lactobacillus?) eurydice strains from bumble bees

Twenty cultures closely resembling Bacterium eurydice, a bacterium associated with honey bees, were isolated from healthy bumble bees and from flowers apparently visited by bees. Their properties suggested that Lactobacillus eurydice would be a more appropriate name for the organism.     

蜜蜂microRNA的研究进展

MicroRNA (miRNA)是一类长度为18~24 nt的内源性非编码小RNA分子,它能通过与靶标mRNA 分子互补结合抑制蛋白质翻译或导致 mRNA 降解,从而调控靶基因表达。蜜蜂是重要的社会性经济昆虫,一直是国际上热门的研究对象。迄今为止,通过各种生物技术在蜜蜂中发现已鉴定注册的miRNA共有218个,对蜜蜂miRNA的研究表明其在蜜蜂的胚胎发育、级型分化、劳动分工和免疫防御等方面可能具有重要的调控作用。本文就miRNA对蜜蜂蜂王和工蜂级型分化、哺育蜂和采集蜂劳动分工、舞蹈行为、脑部神经功能及免疫防御等方面调控作用的最新研究进展进行了综述,以期为进一步研究miRNA提供借鉴和参考。     

Managed bumble bees increase flower visitation but not fruit weight in polytunnel strawberry crops

Animal-mediated pollination is essential for the production and quality of fruits and seeds of many crops consumed by humans. However, crop pollination services might be compromised when wild pollinators are scarce. Managed pollinators are commonly used in crops to supplement such services with the assumption that they will enhance crop yield. However, information on the spatiotemporal pollinator-dependence of crops is still limited. We assessed the contribution of commercial bumble bee colonies compared to the available pollinator community on strawberry (‘Fortuna’ variety) flower visitation and strawberry quality across a landscape gradient of agricultural intensification (i.e. polytunnel berry crop cover). We used colonies of bumble bees in winter and in spring, i.e. when few and most wild pollinators are in their flight period, respectively. The placement of colonies increased visits of bumble bees to strawberry flowers, especially in winter. The use of bumble bee colonies did not affect flower visitation by other insects, mainly honey bees, hoverflies and other Diptera. Flower visitation by both honey bees and wild insects did not vary between seasons and was unrelated to the landscape gradient of berry crop cover. Strawberries were of the highest quality (i.e. weight) when insect-mediated pollination was allowed, and their quality was positively related to wild flower visitors in winter but not in spring. However, increased visits to strawberry flowers by managed bumble bees and honey bees had no effect on strawberry weight. Our results suggest that the pollination services producing high quality strawberry fruits are provided by the flower visitor community present in the study region without the need to use managed bumble bees.     

Specific and sensitive detection of Nosema bombi (Microsporidia: Nosematidae) in bumble bees (Bombus spp.; Hymenoptera: Apidae) by PCR of partial rRNA gene sequences

A polymerase chain reaction (PCR) based method was developed for the specific and sensitive diagnosis of the microsporidian parasite Nosema bombi in bumble bees (Bombus spp.). Four primer pairs, amplifying ribosomal RNA (rRNA) gene fragments, were tested on N. bombi and the related microsporidia Nosema apis and Nosema ceranae, both of which infect honey bees. Only primer pair Nbombi-SSU-Jf1/Jr1 could distinguish N. bombi (323bp amplicon) from these other bee parasites. Primer pairs Nbombi-SSU-Jf1/Jr1 and ITS-f2/r2 were then tested for their sensitivity with N. bombi spore concentrations from 10(7) down to 10 spores diluted in 100 microl of either (i) water or (ii) host bumble bee homogenate to simulate natural N. bombi infection (equivalent to the DNA from 10(6) spores down to 1 spore per PCR). Though the N. bombi-specific primer pair Nbombi-SSU-Jf1/Jr1 was relatively insensitive, as few as 10 spores per extract (equivalent to 1 spore per PCR) were detectable using the N. bombi-non-specific primer pair ITS-f2/r2, which amplifies a short fragment of approximately 120 bp. Testing 99 bumble bees for N. bombi infection by light microscopy versus PCR diagnosis with the highly sensitive primer pair ITS-f2/r2 showed the latter to be more accurate. PCR diagnosis of N. bombi using a combination of two primer pairs (Nbombi-SSU-Jf1/Jr1 and ITS-f2/r2) provides increased specificity, sensitivity, and detection of all developmental stages compared with light microscopy.     

Differential sensitivity of honey bees and bumble bees to a dietary insecticide (imidacloprid)

Currently, there is concern about declining bee populations and the sustainability of pollination services. One potential threat to bees is the unintended impact of systemic insecticides, which are ingested by bees in the nectar and pollen from flowers of treated crops. To establish whether imidacloprid, a systemic neonicotinoid and insect neurotoxin, harms individual bees when ingested at environmentally realistic levels, we exposed adult worker bumble bees, Bombus terrestris L. (Hymenoptera: Apidae), and honey bees, Apis mellifera L. (Hymenoptera: Apidae), to dietary imidacloprid in feeder syrup at dosages between 0.08 and 125 μg l^?1. Honey bees showed no response to dietary imidacloprid on any variable that we measured (feeding, locomotion and longevity). In contrast, bumble bees progressively developed over time a dose-dependent reduction in feeding rate with declines of 10–30% in the environmentally relevant range of up to 10 μg l^?1, but neither their locomotory activity nor longevity varied with diet. To explain their differential sensitivity, we speculate that honey bees are better pre-adapted than bumble bees to feed on nectars containing synthetic alkaloids, such as imidacloprid, by virtue of their ancestral adaptation to tropical nectars in which natural alkaloids are prevalent. We emphasise that our study does not suggest that honey bee colonies are invulnerable to dietary imidacloprid under field conditions, but our findings do raise new concern about the impact of agricultural neonicotinoids on wild bumble bee populations.     

A new threat to honey bees, the parasitic phorid fly Apocephalus borealis

Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pathogens and parasites is the proposed cause for Colony Collapse Disorder (CCD), a syndrome characterized by worker bees abandoning their hive. Here we provide the first documentation that the phorid fly Apocephalus borealis, previously known to parasitize bumble bees, also infects and eventually kills honey bees and may pose an emerging threat to North American apiculture. Parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, we confirmed that phorids that emerged from honey bees and bumble bees were the same species. Microarray analyses of honey bees from infected hives revealed that these bees are often infected with deformed wing virus and Nosema ceranae. Larvae and adult phorids also tested positive for these pathogens, implicating the fly as a potential vector or reservoir of these honey bee pathogens. Phorid parasitism may affect hive viability since 77% of sites sampled in the San Francisco Bay Area were infected by the fly and microarray analyses detected phorids in commercial hives in South Dakota and California's Central Valley. Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD.     

Effects of recent experience on foraging decisions by bumble bees

The temporal and spatial scales employed by foraging bees in sampling their environment and making foraging decisions should depend both on the limits of bumble bee memory and on the spatial and temporal pattern of rewards in the habitat. We analyzed data from previous experiments to determine how recent foraging experience by bumble bees affects their flight distances to subsequent flowers. A single visit to a flower as sufficient to affect the flight distance to the next flower. However, longer sequences of two or three visits had an additional effect on the subsequent flight distance of individual foragers. This suggests that bumble bees can integrate information from at least three flowers for making a subsequent foraging decision. The existence of memory for floral characteristics at least at this scale may have significance for floral selection in natural environments.     

Detection of Deformed wing virus, a honey bee viral pathogen, in bumble bees (Bombus terrestris and Bombus pascuorum) with wing deformities

Honey bees (Apis mellifera) productively infected with Deformed wing virus (DWV) through Varroa destructor (V. destructor) during pupal stages develop into adults showing wing and other morphological deformities. Here, we report for the first time the occurrence of bumble bees (Bombus terrestris, Bombus pascuorum) exhibiting wing deformities resembling those seen in clinically DWV-infected honey bees. Using specific RT-PCR protocols for the detection of DWV followed by sequencing of the PCR products we could demonstrate that the bumble bees were indeed infected with DWV. Since such deformed bumble bees are not viable DWV infection may pose a serious threat to bumble bee populations.     

A comprehensive phylogeny of the bumble bees (Bombus)

Bumble bees ( Bombus Latreille) occupy a wide diversity of habitats, from alpine meadows to lowland tropical forest, yet they appear to be similar in morphology throughout their range, suggesting that behavioural adaptations play a more important role in colonizing diverse habitats. Notwithstanding their structural homogeneity, bumble bees exhibit striking inter- and intraspecific variation in colour pattern, purportedly the outcome of mimetic evolution. A robust phylogeny of Bombus would provide the framework for elucidating the history of their wide biogeographical distribution and the evolution of behavioural and morphological adaptations, including colour pattern. However, morphological studies of bumble bees have discovered too few phylogenetically informative characters to reconstruct a robust phylogeny. Using DNA sequence data, we report the first nearly complete species phylogeny of bumble bees, including most of the 250 known species from the 38 currently recognized subgenera. Bayesian analysis of nuclear (opsin, EF-1α, arginine kinase, PEPCK) and mitochondrial (16S) sequences results in a highly resolved and strongly supported phylogeny from base to tips, with clear-cut support for monophyly of most of the conventional morphology-based subgenera. Most subgenera fall into two distinct clades ( short-faced and long-faced ) associated broadly with differences in head morphology. Within the short-faced clade is a diverse New World clade, which includes nearly one-quarter of the currently recognized subgenera, many of which are restricted to higher elevations of Central and South America. The comprehensive phylogeny provides a firm foundation for reclassification and for evaluating character evolution in the bumble bees.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 161–188.