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1.
Abstract. Multivariate morphometric analysis (canonical variates) was used to discriminate between closely related taxa within the Myzus persicae group. It is demonstrated that dark green, anholocyclic populations with a 2n=13 or 2n=14 karyotype in Europe, hitherto treated as a form or biotype of M.persicae, all conform to a discrete morphometric grouping and should therefore be treated as a separate taxonomic entity, permanently isolated from the M.persicae gene pool. It is suggested that this taxon was first described as Siphonophora antirrhinii by Macchiati in 1883. A discriminant function is provided to separate most individual apterae of antirrhinii from those of persicae. Myzus icelandicus Blackman sp.n., on Caryophyllaceae and other plants in Iceland, is distinguished from M.polaris H.R.L. and M.certus (Walker), and a key is given to apterous virginoparae of the species of the M.persicae group in Europe.  相似文献   

2.
Twenty-seven morphological characters from 111 heteromorphic deutonymphs of the mite genus Chaetodactylus Rondani (Acari: Chaetodactylidae) were analyzed. The mites were collected from four species of bees of the genus Lithurgus Berthold (Hymenoptera: Megachilidae) in continental North America. Principal component and canonical variates analyses on Darroch and Mosimann shape and size-and-shape variables revealed the presence of three cryptic species. Chaetodactylus gibbosi sp. n. (Florida) is geographically isolated from C. lithurgi sp. n. distributed in Texas, New Mexico, Arizona, Colorado, and Idaho. Sympatric C. lithurgi and C. abditus sp. n. (USA: Arizona, Mexico: Socorro Is.) are seasonally isolated in Arizona. Chaetodactylus gibbosi is associated with a single bee species, Lithurgus gibbosus Smith in Florida. The host range of C. lithurgi includes bees flying predominantly in the spring: L. apicalis Cresson, L. littoralis Cockerell, and western L. gibbosus. Chaetodactylus abditus sp. n. is associated with L. planifrons Friese and L. echinocacti Cockerell, flying predominantly in the fall in Arizona. No distinct groups separated by geographic locality or size were detected in any species. A six-variable model developed by the canonical variates analysis and estimated using jackknife resampling and external validation (n=100) is capable of classifying the three species with 100% accuracy. Factors that influenced speciation of cryptic species of Chaetodactylus associated with Lithurgus are discussed. Based on morphological and geographical data and data on mite associates, the western and eastern populations of the bee L. gibbosus are distinct. Therefore, the taxonomic status of L. gibbosus s. lat. should be reevaluated.  相似文献   

3.
ABSTRACT. Analysis of host plant data for the seventy-one species of Diaphorina shows the genus to be unusually polyphagous, the species developing on eighteen families of dicotyledonous angiosperms. Apart from the common Asian citrus pest, Diaphorina citri , a second citrus-feeding species is described and discussed. This species belongs to the amoena species-group which is defined and a key to nine of the ten included species is given. Seven new species are described: flavipennis sp.n. and nigripennis sp.n. from East Africa on Strychnos usambarensis; huila sp.n. from Angola on Ptaeroxylon obliquum; turned sp.n., from South Africa (host unknown); orantimina sp.n. from Madagascar (host unknown); auberti sp.n. from Comoro Islands on citrus trees; and bispinulata sp.n. from Madagascar (host unknown).  相似文献   

4.
Multivariate analysis of variance (MANOVA) and canonical variates analysis (CVA) were used to examine differences in host plant resistance and pathogen behaviour in interactions between Altemaria linicola and three genotypes of Linum usitatissimum, previously identified as susceptible, moderately resistant and resistant to the pathogen. Significant differences in pathogen development were found among the Linum accessions at 18, 24, and 40 h after inoculation. At 18 h after inoculation attempted penetration by the pathogen was relatively rare on all three accessions and canonical variates analysis revealed that overall differences among accessions resulted from large differences with respect to a small number of variables associated with successful penetration on the most susceptible accession. At later times after inoculation, when attempted penetration was more common, overall differences among accessions were found to result from smaller absolute differences among a group of variables which characterised the early colonisation of the host tissue. The results from these investigations are discussed in relation to recent research on the ecology of the pathogen and the importance of the timing of host responses to infection in determining host plant resistance.  相似文献   

5.
A study of monogenean gill parasites from three species of the genus Clarias Scopoli, 1777 (Clariidae), namely Clarias camerunensis L?nnberg, 1895, C. jaensis Boulenger, 1909 and C. pachynema Boulenger, 1903, from the Nyong Basin (Cameroon) revealed the presence of three new monogenean species of the new genus Birgiellus, namely Birgiellus mutatus n. sp. from C. pachynema, B. calaris n. sp. from C. jaensis and B. kellensis n. sp. from C. camerunensis. The genus Birgiellus differs from the genus Quadriacanthus by the morphology of the ventral bar composed of a single piece (two distinct in Quadriacanthus) and the size of the uncinuli IV, which are not much different from the others (longest in Quadriacanthus). Birgiellus calaris differs from B. mutatus by its ventral anchors longer and larger, the morphology of the ventral bar with a short incision between the two branches, and a long and trapezoid handle, the size of the sclerotised structures of the male and female copulatory organs, the larger thickness of the hook in the male accessory piece, the latter having also a heel. Birgiellus kellensis is closer to B. calaris but can be distinguished by the small size of its dorsal and ventral anchors, its transverse bars, male copulatory organ, and the accessory piece, which also has not a heel but a secondary blade. According to the clause 8.5.2 of the International Zoological Code of Nomenclature (1999) the genus Birgiellus and the species B. mutatus and B. calaris, respectively, replace Claridectes, C. clarisa and C. alacris previously described by Birgi (1987), but whose specimens were not deposited in a museum. All the three taxa described exhibit a strict (oioxenous) host specificity.  相似文献   

6.

Background  

We generalized penalized canonical correlation analysis for analyzing microarray gene-expression measurements for checking completeness of known metabolic pathways and identifying candidate genes for incorporation in the pathway. We used Wold's method for calculation of the canonical variates, and we applied ridge penalization to the regression of pathway genes on canonical variates of the non-pathway genes, and the elastic net to the regression of non-pathway genes on the canonical variates of the pathway genes.  相似文献   

7.
The endemic Australian genus Bonjeania Irwin & Lyneborg is revised. Seven species are described as new: B. angelikae sp.n., B. clamosis sp.n., B. dynastis sp.n., B. flavofemoralis sp.n., B. irwinae sp.n., B. orphne sp.n. and B. trilineata sp.n. Three species, B. actuosa (White), B. nitidifrons (Macquart) and B. segnis (White), are redescribed. All species of Bonjeania were compared in a cladistic analysis with Agapophytus albobasalis Mann and five exemplars of the speciose sister genus Parapsilocephala Kröber, and the phylogenetic relationships of Bonjeania discussed. The male genitalic musculature of B. clamosis sp.n. is described and figured, and discussed with respect to previous studies on other Therevidae.  相似文献   

8.
The New World genus Bezzimyia Townsend, 1919 is revised and the following 15 new species are described: B. barbarista sp. n., B. bisecta sp. n., B. bulbosa sp. n., B. floridensis sp. n., B. hansoni sp. n., B. jamaica sp. n., B. lapidicina sp. n., B. orestes sp. n., B. pittieri sp. n., B. platina sp. n., B. ramicornis sp. n., B. setifax sp. n., B. sternothrix sp. n., B. thompsonorum sp. n. and B. yepezi sp. n. The oviposition, egg and first instar larva are described for Bezzimyia yepezi from Venezuela. It is argued that Bezzimyia is a member of the family Rhinophoridae, which was previously considered to be represented in the New World only through two immigrant Palaearctic species.  相似文献   

9.
本文报道采自浙江、福建、广东、云南的跳小蜂六新种 ,即瘤毡蚧花翅跳小蜂MicroterysmetaceronemaeXu、露尾花翅跳小蜂MicroterysnuticaudatusXu、后缘花翅跳小蜂MicroteryspostmarginisXu、拟聂特花翅跳小蜂MicroteryspseudonietneriXu、匀色花翅跳小蜂MicroterysunicolorisXu、赵氏花翅跳小蜂MicroteryszhaoiXu。除露尾花翅跳小蜂MicroterysnuticaudatusXu ,sp .n .寄主尚不明确外 ,其余种类均为林木上各种介壳虫的寄生蜂。对新种进行了详细描述 ,并附特征图。标本存放浙江大学植物保护系。  相似文献   

10.
The Brachylaimidae of Australian native animals are revised. Brachylaima dasyuri (Johnston, 1913) is redescribed from Dasyurus viverrinus, Phascogale tapoatafa and Isoodon macrourus. B. simile (Johnston, 1913) is removed from synonymy with B. dasyuri, reinstated as a valid species and redescribed from Perameles nasuta, Isoodon obesulus and Antechinus stuartii. B. antechini Peisley & Howell, 1975 is reduced to synonymy with B. simile. B. brindabellensis n. sp. is described from Rattus fuscipes. B. walterae n. sp. is described from Antechinus swainsonii and A. stuartii. B. delecta n. sp. is described from Antechinus flavipes. B. sandarsae n. sp. is described from Antechinus godmani. B. pulchellum (Johnston, 1917) is redescribed from Leucosarcia melanoleuca. An unnamed Brachylaima species is described from Isoodon macrourus. New host records are Brachylaima dasyuri from Phascogale tapoatafa and B. simile from Perameles nasuta. Dasyurotrema mascomai n. g., n. sp. is described from Antechinus swainsonii. The new genus is placed in the Panopistinae. It differs from the existing genera by having a single loop of the uterus passing anterior to the ventral sucker and the genital pore posterior to the posterior testis but still distinctly ventral. A second species of Dasyurotrema is recorded, but not described, from Antechinus stuartii. Brachylaimid metacercariae are described from Rhytida capillacea, Helicarion virens, H. mastersi and Vercularion strangei. In no case was a host species found to harbour more than one species from any brachylaimid genus at a single geographical site.  相似文献   

11.
The Neotropical species of the rarely collected genus Bolitogyrus (Coleoptera: Staphylinidae: Staphylininae: Staphylinini) are revised. The genus exhibits an uncommon, disjunct distribution between the Neotropical and Oriental Regions and is of unknown phylogenetic position within Staphylinini. Morphological evolution remarkable for Staphylinini was discovered within Bolitogyrus, including sexually dimorphic modifications of the pronotum that may be involved in male competition for females. rSEM interactive animations were used to establish morphological species boundaries between two highly variable species and are provided to illustrate diagnostic characters of the genitalia in unconventional views. The genus is redescribed based on the world fauna and twenty-eight Neotropical species are considered valid. Of these, nineteen are described as new to science: Bolitogyrus ashei sp. n.; B. apicofasciatus sp. n.; B. brevistellus sp. n.; B. bufo sp. n.; B. cheungi sp. n.; B. cornutus sp. n.; B. divisus sp. n.; B. falini sp. n.; B. gracilis sp. n.; B. inexspectatus sp. n.; B. longistellus sp. n.; B. marquezi sp. n.; B. newtoni sp. n.; B. pseudotortifolius sp. n.; B. pulchrus sp. n.; B. silex sp. n.; B. thomasi sp. n.; B. tortifolius sp. n.; and B. viridescens sp. n. Bolitogyrus sallei (Kraatz), stat. r. is removed from synonymy with B. buphthalmus (Erichson) and the following new synonyms are proposed: Cyrtothorax cyanescens Sharp, 1884, syn. n. = Quedius buphthalmus Erichson, 1840; C. nevermanni Scheerpeltz, 1974, syn. n. = C. costaricensis Wendeler, 1927. A summary of all available bionomic and distributional data, as well as an illustrated identification key to and diagnoses of all Neotropical species are provided.  相似文献   

12.
Three new mite species of the genus Magimelia (Astigmata: Pterolichidae) are described from the plumage of various lapwings (Charadriidae: Vanellinae): M. breviloba n. sp. from Vanellus miles miles; M. thailandica n. sp. from V. indicus (type-host), V. duvaucelii and V. tricolor; and M. chilensis n. sp. from V. chilensis. An extended host range for M. dolichosikya Gaud, 1961 is given. A revised diagnosis of the genus and a key to known species are presented.  相似文献   

13.
14.
The mylabrine genus Pseudabris is endemic to the Tibetan Plateau and includes seven species with overlapping or disjunct ranges. The genus is revised: three new species, P. brevipilosa sp.n., P. latimaculata sp.n., P. regularis sp.n., are described and illustrated, and a key to the species is provided. Molecular evidence supports the placement of Pseudabris within the tribe Mylabrini. Results of a morphology‐based cladistic analysis support the existence of two lineages, one centred mainly on the south central plateau, and the second in the eastern area. Faunistics and bionomics of the genus are summarized, focusing on phenology, elevation, habitat preference and host plants. The endemism of the Tibetan Plateau is discussed, with a special focus on the genus Pseudabris.  相似文献   

15.
The genus Bewsiella is considered to comprise a considerable number of species, despite having been regarded as monotypic. The structure of the male spermadactyl is proposed as a key character for separating congeneric species. This character seems likely to bear phylogenetic information on both the mites themselves and their hosts. Since the male of Bewsiella fledermaus Domrow, the type-species, has not been found, it is impossible to define the morphology of this species based on both sexes. Consequently, all mites that share many characters with the female of B. fledermaus are placed in a B. fledermaus species group. B. aelleni (Till) is considered as a valid species and both sexes and the protonymph are redescribed and illustrated. B. nycteris n. sp., B. emballonuris n. sp., B. cloeotis n. sp., B. haradai n. sp. and B. coelopos n. sp. are described and illustrated. The genus Bewsiella was originally allocated to the family Laelapidae and later transferred to the family Macronyssidae. Recently, the genus was returned to the Laelapidae, and some evidence supporting this action was obtained during the present study, but further studies are required for confirmation.  相似文献   

16.
Low-resolution pyrolysis gas-liquid chromatography (p.g.l.c.) can differentiate genera of aerobic food spoilage bacteria. Multivariate statistical techniques were applied but neither principal components nor furthest neighbour cluster analysis produced a consistent differentiation although both confirmed the reproducibility of p.g.l.c. When the distance between genera was redefined in terms of Mahalanobis D2- a generalized concept taking into account scatter around the mean-good differentiation was observed and could be displayed graphically by plotting the genus group means relative to the first two canonical variate axes. The coefficients of the canonical variates provide a strategy for discriminating between the genus groups. Some practical problems in the identification of unknowns using this technique are discussed.  相似文献   

17.
18.
Lake Tanganyika harbours the most diverse endemic cichlid fish assemblage of Africa, but its monogenean fish parasites have not been investigated. Here we report, for the first time, on the Gyrodactylus parasites in this hotspot of fish biodiversity. Haptor morphometrics and nuclear ribosomal DNA sequences revealed 3 new species on Zambian Simochromis diagramma: Gyrodactylus sturmbaueri n. sp., G. thysi n. sp. and G. zimbae n. sp. Their distinct morphology and strong genetic differentiation suggest that they belong to distant lineages within the genus Gyrodactylus, and phylogenetic reconstructions suggest affinities with other genera of gyrodactylids. Additional U-shaped haptoral plates in G. thysi n. sp. and a second large spine-like structure in the male copulatory organ of G. zimbae seem to represent new features for the genus. Such large diversity on a single host species can probably be explained by host-switching events during the course of evolution, in agreement with the generally accepted concept that ecological transfer is an important aspect of gyrodactylid speciation. Additional parasitological surveys on other host species, covering a broader phylogenetic and geographical range, should clarify the evolutionary history of Gyrodactylidae on cichlids in the African Great Lake and other parts of Africa.  相似文献   

19.
为了明确取食相同植物不同部位和营不同虫瘿的蚜虫是否存在形态适应,论文以取食杨属Populus植物的10种蚜虫为研究对象,基于蚜虫喙末端、各足跗节和爪的形态测量数据,对122个克隆的形态变异通过一般的统计描述、典型变量分析(canonical variates analysis,CVA)以及聚类分析等方法进行了研究。结果显示,不同的蚜虫克隆间形态特征存在分异,与不同的虫瘿类型和取食部位相关。3个典型变量分析明显地区分了形成虫瘿和不形成虫瘿的蚜虫克隆,在叶片上形成真虫瘿和伪虫瘿的克隆以及不产生虫瘿的克隆,并形成明显的克隆簇。而用于分析的形态学特征,如喙末端、跗节和爪的测量值,其一般统计描述的差异也支持这些区分。蚜虫自然种群不同克隆簇的区分很好地对应了不同的取食部位和不同的虫瘿类型,且各簇的形态特征体现了各自的特点,表明了蚜虫对杨属植物已经形成了良好的形态适应。同时,也初步讨论了不同蚜虫克隆簇形态适应产生的原因。并建议在基于形态特征探讨昆虫的系统发育关系和进行传统分类时,必须考虑昆虫形态特征的适应性;在深入研究昆虫与寄主植物相互之间关系时,需要将各种形态特征综合考虑并关注其它的影响因素。  相似文献   

20.
Canonical correlation analysis is applied to measurements of environmental variables and species distributions made during a survey of macrobenthos around a sewage-treatment farm drain. The implications of data reduction, necessary to enable the method to proceed, are discussed. The amount of data was reduced by discarding the rarest species, discarding species occurring at fewest stations, and including only those species and environmental variables which correlated highly with the greatest number of other variables. Only the third data-reduction scheme gave ecologically sensible results. Use of station scores on the first two canonical variates (CV1 and CV2) enabled the sampling grid to be divided into a group of nearshore stations, a group of intermediate depth, and a group of deep offshore stations. Loadings of environmental variables on the canonical variates were found to be unstable but correlations between these variables and canonical variates enabled the variates to be interpreted: CV1 as a gradient of depth and associated changes in sediment characteristics, CV2 with depth- and nutrient-related components, and CV3 as patchiness in sediment characteristics different from that normally expected with depth. Use of correlations between species and canonical variates enables definition of two major species groups, one confined to nearshore environments and a second offshore. These groups (and their sub-groups) related well to groups defined previously by hierarchical classification. It is concluded that, with careful attention to the method of data reduction, canonical correlation analysis can be an effective tool in the analysis of marine benthic survey data.  相似文献   

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