Cantharidin content in two Mediterranean species of blister beetles,Lydus trimaculatus and Mylabris variabilis (Coleoptera: Meloidae)

Cantharidin (CA), a toxic terpene produced by blister beetles (Coleoptera: Meloidae), attracts the interest of many researchers for its renowned medical properties. The CA content in blister beetles has been mainly quantified in some Oriental species, due to their use in traditional Chinese medicine, or in few other species of toxicological importance. As CA quantification has been largely ignored in many other members of this family, we aimed at estimating CA content in natural populations of two of the most abundant species in central Italy, Mylabris variabilis and Lydus trimaculatus. Nearly 100 individuals for each species were collected in the field, identified and reared in fauna‐boxes until CA collection. Available protocols were optimized for CA extraction from both dried‐body tissues and exuded hemolymph collected from leg joints using capillary tubes. The CA content was quantified in a gas chromatography system coupled to a mass spectrometer using a calibration curve with diethyl‐ester of norcantharidin as the internal standard. We observed: (i) high variability in CA content among specimens, which was positively related to individual dry‐weight; and (ii) slightly larger (though non‐significant) amount of CA in males than in females for both species. Our data are consistent with the available published reports about CA content, transfer and distribution in blister beetles and suggest a conserved biological role of this terpene in Meloidae.     

中国北方常见芫菁分子物种界定(鞘翅目: 芫菁科)

【目的】应用线粒体COI和核CAD基因片段探讨自动条形码间隔探索(automatic barcode gapdiscovery, ABGD)、广义混合Yule溯祖模型(generalized mixed Yule coalescent, GMYC)、贝叶斯泊松树进程(Bayesian Poisson tree processes, bPTP)和贝叶斯系统发育和系统地理分析(Bayesianphylogenetics and phylogeography, BPP) 4种分析方法在芫菁科(Meloidae)昆虫分子物种界定中的适用性。【方法】分别基于COI, CAD和COI+CAD串联序列数据集,应用ABGD, GMYC, bPTP和BPP 4种方法对中国北方芫菁科常见的6属(沟芫菁属Hycleus、斑芫菁属Mylabris、豆芫菁属Epicauta、绿芫菁属Lytta、星芫菁属Megatrachelus和短翅芫菁属Meloe)18个形态种进行分子物种界定,并与形态学鉴定结果进行比较。【结果】利用COI+CAD串联序列数据集所得物种界定结果与形态鉴定结果一致;COI数据集使用ABGD和GMYC方法的界定结果与形态鉴定结果一致,而bPTP划分的物种数较形态鉴定结果多;基于CAD序列在3种单基因物种界定方法的结果中,除GMYC与形态划分一致外,其余均显示部分结果与形态划分不同。【结论】在芫菁科分子物种界定中,多基因联合序列、多种界定方法分析所得结果优于单一基因片段和界定方法的分析结果。本研究的结果为芫菁科昆虫的分子物种界定和整合分类提供了数据支持和参考。     

Phylogeny and evolutionary history of the blister beetles (Coleoptera, Meloidae)

Meloid beetles are well characterised by both morphological and biological features. Previous phylogenetic hypotheses based on morphological characters assumed the repeated parallel evolution of complex biological novelties. In this work relationships among several taxa of the four subfamilies and almost all tribes representing meloid diversity are examined by using mitochondrial (16S) and nuclear (ITS2) DNA sequences, in 25 genera (using Anthicidae as outgroup). Secondary structure of 16S and ITS2 rRNAs were modelled. ITS2 structure represents a synapomorphic condition for the family and informative characters at the tribal level. Phylogenetic hypotheses based on separate and combined analysis of the 16S and ITS2 rDNA sequences, and morpho-biological characters were tested, and compared with previous morphological classifications. Molecular dating allowed an outline of the main steps of the evolutionary history of Meloidae, which evolved during Early Cretaceous and then radiated considerably with the adoption of hypermetaboly and parasitic behaviour, and with repeated, parallel evolution of larval phoresy on its hosts.     

芫菁体内斑蟊素的合成、 转移和生物学功能

斑蟊素是芫菁科昆虫合成的一种防御物质, 已经被证实对多种癌症和其他疾病有着特殊的疗效。芫菁体内存在不同结合态的斑蟊素或斑蟊素衍生物, 包括斑蟊素酸镁、斑蟊素酸钙、羟基斑蟊素、甲基斑蟊胺和脱甲斑蟊素等。不同芫菁种类、不同发育阶段其斑蝥素合成量有显著的差异, 并且有着典型的性二型现象, 性成熟的雄成虫斑蝥素含量最高可达10%。关于斑蝥素的生物合成途径以及斑蝥素在虫体内的分布, 尽管有一些研究, 但仍然没有定论。本文从斑蟊素在芫菁体内的含量、分布、生物合成、代谢及生物学功能等方面对国内外的研究进行概括, 以期为充分发掘芫菁科昆虫资源、指导芫菁的人工养殖、合理的利用资源以及人工合成斑蟊素提供参考。     

Cladistic and phenetic estimates of relationship among genera of eupomphine blister beetles (Coleoptera: Meloidae)

Abstract. The Eupomphina includes seven distinctive genera of Meloidae from the arid and semiarid zones of North America. Cladistic and phenetic estimates of relationship among genera are analysed and discussed. Both adult and larval characters are used, and the relative contribution of each to the classification of the subtribe is examined. Generic keys to adults and first instar larvae are included.     

中国斑芫菁后翅形态比较

选取中国斑芫菁属11个代表种,对比分析了它们的后翅形态特征; 以苹斑芫菁Mylabris calida Pallas, 1782为模式,探讨了斑芫菁属后翅的翅脉名称,并对其性状进行了描述。研究结果将斑芫菁属翅脉归纳为3种类型：1）南方型：东洋种,翅深褐色,各脉粗大,骨化程度高,皱褶多而明显;2）高原型：青藏高原特有种,翅乳白色,半透明,仅前缘和MP_1＋2形成明显的大翅室,余脉淡而不显,骨化程度低;3）北方型：为以上两种类型的中间过渡,古北种,翅褐色,各脉清晰,中度骨化。根据研究结果,初步探讨了斑芫菁属翅脉的形态进化。     

Contributions to molecular systematics of water scavenger beetles (Hydrophilidae,Coleoptera)

Phylogenetic relationships within Hydrophilidae were examined by analyses of separate and combined nuclear and mitochondrial markers (28S rRNA, 18S rRNA, 16S rRNA, 12S rRNA, COI and COII genes). The preferred (Bayesian) tree topology suggests a sister group relationship between Spercheidae and Hydrophilidae, supporting the ‘hydrophilid lineage’; Epimetopidae are placed on the base of the ‘helophorid branch’, the monophyly of Sphaeridiinae is highly supported, nested deeply within Hydrophilidae closest to Enochrus, making Hydrophilinae and Acidocerini paraphyletic; Hydrobius appears as sister taxon to (Hydrochara + Hydrophilus) without a closer relationship to Acidocerini; the hydrophiloid–histeroid sister group relationship is confirmed. The topology of several taxa remains contradictory, and requires further investigations with a larger taxon sampling and additional molecular markers.     

A new Mylabris species from south-eastern Iran and a key to the Iranian species of the nominate subgenus (Coleoptera, Meloidae)

A new species of Mylabris of the nominate subgenus is described and figured. This species is apparently endemic to the south-eastern Iranian province of Kerman and seems to be phenetically very distinct from all other species of this subgenus, primarily because of the unique elytral pattern. A key to the species of the nominate subgenus distributed in Iran is also presented.     

Isolation and identification of AKH/RPCH family peptides in blister beetles (Meloidae)

Abstract. Two peptides were isolated from methanolic extracts of corpora cardiaca of the blister beetle, Decupotoma lunata , by a single-step purification procedure, utilizing C-18 reversed-phase high-performance liquid chromatography (RP-HPLC) for separation, and the increase of haemolymph lipids in Locusta migratoria for bioassay. The native peptides were analysed by matrix-assisted laser-desorption ionization mass spectrometry revealing main ions at m/z 1180 and 1009 respectively which were attributed to the [M + Na]⁺ form of the respective peptides. After deblocking of the N-terminal pyroglutamate residue of each peptide, the structures of the deblocked peptides were determined by pulsed-liquid phase sequencing employing Edman chemistry. The sequences of the two peptides, (1) pGlu-Leu-Asn-Phe-Ser-Pro-Am-Trp-Gly-AsnNH₂ and (2) pGlu-Leu-Asn-Phe-Ser-Pro-Asn-TrpNH₂, characterize them as deca- and octapeptide members of the AKH/RPCH family. Whereas the decapeptide is a novel member of this family and is given the acronym Del-CC ( Decupotoma lunata corpus cardiacum peptide), the octapeptide has previously been found in tenebrionid beetles and has the acronym Tem-HrTH. The corpora cardiaca of two other species of blister beetles ( Cyaneolytta pectoralis and Mylabris coeca ) contain the same two peptides as D. lunata , as judged by RP-HPLC and biological activity. Neither a corpus cardiacum extract of Decupotoma lunata nor the synthetic peptides Del-CC and Tem-HrTH were active in mobilizing carbohydrates or lipids in the blister beetle.     

Phylogenetic systematics of the colorful, cyanide-producing millipedes of Appalachia (Polydesmida, Xystodesmidae, Apheloriini) using a total evidence Bayesian approach

Here, we provide an exemplar-approach phylogeny of the xystodesmid millipede tribe Apheloriini with a focus on genus-group relationships-particularly of the genus Brachoria. Exemplars for the phylogenetic analysis were chosen to represent the maximum breadth of morphological diversity within all nominal genera in the tribe Apheloriini, and to broadly sample the genus Brachoria. In addition, three closely related tribes were used (Rhysodesmini, Nannariini, and Pachydesmini). Morphological and DNA sequence data were scored for Bayesian inference of phylogeny. Phylogenetic analysis resulted in polyphyletic genera Brachoria and Sigmoria, a monophyletic Apheloriini, and a "southern clade" that contains most of the tribal species diversity. We used this phylogeny to track morphological character histories and reconstruct ancestral states using stochastic character mapping. Based on the findings from the character mapping study, the diagnostic feature of the genus Brachoria, the cingulum, evolved independently in two lineages. We compared our phylogeny against prior classifications using Bayes factor hypothesis-testing and found that our phylogenetic hypothesis is inconsistent with the previous hypotheses underlying the most recent classification. With our preferred total-evidence phylogeny as a framework for taxonomic modifications, we describe a new genus, Appalachioria; supply phylogenetic diagnoses of monophyletic taxa; and provide a phylogeny-based classification for the tribe Apheloriini.     

Phylogenetic relationships of Dalyat mirabilis Mateu, 2002, with a revised molecular phylogeny of ground beetles (Coleoptera, Carabidae)

Dalyat mirabilis Mateu 2002 (Coleoptera: Carabidae) is a cave species recently described from SE Spain, which, based on morphological analyses, has been related to the Promecognathinae (with one genus in western North America and four genera in South Africa). In this paper, we investigated the phylogenetic relationships of the main lineages of family Carabidae, and the placement of Dalyat among them, with the 18S rRNA full sequence and a fragment of wingless with the use of parsimony, a fast maximum likelihood algorithm (implemented in the program phyml ), and Bayesian posterior probabilities. Although with wingless alone the relationships of Dalyat were not robustly supported, both with 18S rRNA and in a combined analysis there was a strong support for a sister relationship between Promecognathus and Dalyat with the three methods used. Using a molecular-clock approach the two lineages were estimated to have diverged at a similar (or slightly earlier) age than the origin of Harpalinae, known to have radiated in the Cretaceous. This is compatible with a vicariant origin of the lineage leading to Dalyat because of the isolation of the Iberian plate from Pangea in the late Jurassic to early Cretaceous. Other robust relationships within the Carabidae are the monophyly of Harpalinae (including Morionini, Peleciini and Pseudomorphini), its sister relationship with Brachininae, and the inclusion of these two subfamilies together with Scaritini and the austral Psydrinae in a strongly supported clade (the 'higher' Carabidae).     

人工饲养条件下眼斑芫菁不同发育阶段斑蝥素含量的变化

【目的】分析人工饲养条件下眼斑芫菁Mylabris cichorii Linnaeus不同发育阶段体内斑蝥素含量的变化。【方法】收集不同发育阶段的眼斑芫菁,通过热碱浸提法提取斑蝥素,而后以气相色谱法检测含量。【结果】在幼虫期,1龄幼虫斑蝥素相对含量最高,2龄幼虫斑蝥素相对含量降到最低点;以后随着虫体的发育,幼虫体重和斑蝥素含量都逐渐增加。羽化后的成虫经隔离饲养,雄虫在羽化后5～30天大量合成斑蝥素,而雌虫体内斑蝥素含量则极低,具有典型的性二型现象;雌雄混合饲养组中,20～30天雌虫体内可以检测到大量斑蝥素,而同期雄虫斑蝥素含量远低于隔离饲养组。【结论】幼虫期斑蝥素含量随虫体发育而增加;成虫期主要由雄虫合成斑蝥素。混合饲养组成虫平均单头斑蝥素含量高于隔离饲养组雌雄虫平均斑蝥素含量。成虫身体各部位的斑蝥素含量以腹部最高,胸部次之。     

Phylogenetic systematics of Erythronium (Liliaceae): morphological and molecular analyses

For a nearly complete set of species of Erythronium (Liliaceae), we examined two plastid loci (the rps16 intron and the 5′ trnK intron, excluding the matK exon), one nuclear locus (nrITS) and morphology to evaluate species relationships and that of Erythronium to Amana, the putatively most closely allied genus. A matrix of morphological characters was developed through observation of around 900 living and herbarium specimens; evolution of these was examined using character optimization on the combined (total‐evidence) tree. Parsimony methods were used to examine the morphological and molecular data sets produced, both separately and in combination, with Bayesian methods also used on the molecular data sets. These established that the genus is probably sister to Amana (although most analyses placed Amana inside Erythronium) and that Tulipa is sister to the pair of Erythronium and Amana. Within Erythronium, there are three strongly supported geographically distinct clades: (1) Eurasian and (2) eastern and (3) western North American. Separation of species in these three clades is less clear, particularly among the western North American taxa. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ●●, ●●–●●.     

大斑芫菁和棉蝗间的发育同步性研究

寄生物和寄主的发育关联研究已有很多报道,而人们对捕食者与猎物的同步发育关系却知之甚少。本文研究了大斑芫菁Mylabris phalerata及其猎物棉蝗Chondracris rosea rosea在18℃、22℃、25％、28℃、31℃和34℃恒温下的发育特性及发育同步性。大斑芫菁幼虫（除5龄外）发育起点温度均低于10℃,而棉蝗每个阶段的发育起点温度都高于10℃。大斑芫菁5龄幼虫的有效积温为440．53日度,低于棉蝗卵的462．96日度,并且大斑芫菁1～4龄幼虫的有效积温均少于1—4龄蝗蝻。大斑芫菁成虫出现、卵孵化和幼虫滞育解除日期与棉蝗产卵和卵孵化日期,显示大斑芫菁的发育和棉蝗的发育具有季节同步性,而且大斑芫菁的滞育同步化了大斑芫菁和棉蝗的发育。     

大斑芫菁滞育幼虫在滞育不同阶段体内糖类和醇类含量的变化

在以卵滞育的昆虫中昆虫滞育时的生理代谢特点已经得到了大量研究。本文对以末龄幼虫（5龄）滞育的大斑芫菁Mylabris phalerate（Pallas）在不同滞育阶段体内糖类和醇类代谢的特征进行了研究。结果表明： 滞育个体血淋巴中的海藻糖含量高于非滞育个体,且随滞育时间的加大逐渐升高,滞育5个月时达到最大值,为5.61 μmol/mL。糖原的含量随滞育的进程逐渐减少,滞育初期（0.5个月）为0.72 mg/mL,到滞育末期（5个月）时仅为0.1 mg/mL。滞育个体脂肪体中的海藻糖含量都高于非滞育个体,滞育1个月时为非滞育个体的3倍,至滞育末期时达非滞育个体的5倍,为2.5 μmol/g脂肪体。糖原含量总体变化趋势是随滞育时间的加大逐渐减少,滞育早期和中期都高于非滞育个体。在滞育过程中血淋巴积累的小分子多元醇主要为甘油,其次是山梨醇;而在脂肪体中主要为甘油,其次是甘露醇,少量积累山梨醇：表明大斑芫菁滞育幼虫主要积累的是海藻糖和一些小分子多元醇。滞育幼虫在准备滞育时储备了大量糖原,这些糖原可能为滞育期间海藻糖、山梨醇和甘油的代谢提供了原料。     

New species of leaf beetles (Coleoptera, Chrysomelidae) from China: VI

Smaragdina schereri sp. n., Chrysolina jiangi sp. n., Ch. geae sp. n., Ch. gansuica sp. n., Sclerophaedon daccordii sp. n., Neophaedon sichuanicus sp. n., Oreomela inflata sp. n., Xingeina nigrolucens sp. n., Shaira hemipteroides sp. n. and Calomicrus atroviridis sp. n. from Sichuan, Gansu, and Yunnan provinces of China are described. Types of the new species are deposited in the Zoological Institute, Russian Academy of Sciences, St. Petersburg.