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Geosmithia belongs among fungi living in symbiosis with phloem-feeding bark beetles. Several species have altered their ecology to that of obligatory symbiosis with ambrosia beetles, which has led to a shift in their phenotype and caused formation of large spherical conidia. In this study, we pose the following questions; (1) Is the conidial DNA content of Geosmithia correlated with conidial volume?; (2) Is the DNA content of Geosmithia related to the degree of mutual dependence between Geosmithia and their vector? There was a positive and strong correlation between conidial DNA content and conidial volume in Geosmithia. Also species more narrowly associated with the vector tend to have a larger conidial DNA content and volume than less narrowly associated species. Ambrosia fungi achieved the biggest conidial DNA content and volume compared to other species. We suppose that polyploidisation occurred during the evolution of ambrosia species in the genus Geosmithia.  相似文献   

3.
Three new species of scarabaeoid beetles of the family Hybosoridae are described in the new genus Protohybosorus, gen. nov. from the Middle-Upper Jurassic of Kazakhstan (Karatau-Mikhailovka locality). The Lower Cretaceous species Geotrupoides fortus Ren, Zhu et Lu, 1995 (Inner Mongolia, China) is transferred to the genus Leptosorus Nikolajev, 2006.  相似文献   

4.
Calligrapha is a New World leaf beetle genus that includes several unisexual species in northeastern North America. Each unisexual species had an independent hybrid origin involving different combinations of bisexual species. However, surprisingly, they all cluster in a single mtDNA clade and with some individuals of their parental species, which are in turn deeply polyphyletic for mtDNA. This pattern is suggestive of a selective sweep which, together with mtDNA taxonomic incongruence and occurrence of unisexuality in Calligrapha, led to hypothesize that Wolbachia might be responsible. I tested this hypothesis studying the correlation between diversity of Wolbachia and well‐established mtDNA lineages in >500 specimens of two bisexual species of Calligrapha and their derived unisexual species. Wolbachia appears highly prevalent (83.4%), and fifteen new supergroup‐A strains of the bacteria are characterized, belonging to three main classes: wCallA, occupying the whole species ranges, and wCallB and wCallC, narrowly parapatric, infecting beetles with highly divergent mtDNAs where they coexist. Most beetles (71.6%) carried double infections of wCallA with another sequence class. Bayesian inference of ancestral character states and association tests between bacterial diversity and the mtDNA genealogy show that each mtDNA lineage of Calligrapha has specific types of infection. Moreover, shifts can be explained by horizontal or vertical transfer from local populations to an expanding lineage and cytoplasmic incompatibility between wCallB and wCallC types, suggesting that the symbionts hitchhike with the host and are not responsible for selective mtDNA sweeps. Lack of evidence for sweeps and the fact that individuals in the unisexual clade are uninfected or infected by the widespread wCallA type indicate that Wolbachia does not induce unisexuality in Calligrapha, although they may manipulate host reproduction through cytoplasmic incompatibility.  相似文献   

5.
A new genus and two new species of water scavenger beetles, Hydrophilopsia bontsaganica, sp. nov. and Prospercheus cristatus, gen. et sp. nov., are described from the Upper Jurassic and Lower Cretaceous of Mongolia. The systematic position of the new genus is discussed.  相似文献   

6.
Most lineages in the African genus Protea consist of species with large unscented flowers pollinated principally by birds, and several of these lineages also show evidence of shifts to rodent pollination, associated with concealed yeasty-scented flowerheads. In this study we investigated the hypothesis that brightly coloured and fruity-scented flowerheads of four Protea species (P. caffra, P. simplex, P. dracomontana and P. welwitschii) represent a novel shift from bird to insect pollination in a grassland lineage in the genus. These species are visited by a wide range of insects, but cetoniine beetles were found to be the most important pollinators because of their abundance, size and relatively pure pollen loads. Three of the four putatively insect-pollinated Protea species have flowers presented at ground level, and experiments showed that cetoniine beetles preferred inflorescences at ground level to those artificially elevated to the height of shrubs and small trees. Relative to insects, birds were infrequent visitors to all of the study species. The nectar of all the study species contained xylose, as documented previously in bird- and rodent-pollinated Protea species, suggesting that this is a phylogenetically conserved trait. However, the very low concentration of nectar (ca. 8%), short nectar-stigma distance and the fruity scent of florets appear to be traits that are associated with specialisation for pollination by cetoniine beetles.  相似文献   

7.
A new genus, Baltoraea gen. nov., two new species of this genus, B. insignis sp. nov. and B. simillima sp. nov., and three other new species, Cybocephalus (Cybocephalus) balticus sp. nov., C. (C.) electricus sp. nov. and C. (C.) kerneggeri sp. nov. are described from the Late Eocene Baltic amber. The systematic position of the genus Baltoraea and presumable bionomics of the new sap beetles are discussed.  相似文献   

8.
The soldier defense secretions of advanced neotropical termites of the genus Subulitermes (Isoptera, Nasutitermitinae) contain diterpenes identicalto those found in Nasutitermes species, while soldiers of the primitive mandibulate nasute genera Cornitermes, Armitermes and Rhynchotermes lack diterpenoid compounds. It now appears improbable that the elongate nasus and intimately associated terpenoid defense secretions evolved from a primitive mandibulate ancestor independently along two phyletic branches. An alternate hypothesis is proposed in which morphological divergence from a common diterpene-producing ancestor may have occurred.  相似文献   

9.
Dermaphis coccidiformis sp. nov. (Hormaphidinae: Nipponaphidini) is described from Japan. Apterous adults of the species were found between winter buds (or between a winter bud and a leaf petiole) of the evergreen oaks Quercus glauca, Q. myrsinifolia and Q. salicina. Their morphology is peculiar in that their tergites are heavily sclerotized only in the part that seems to have been exposed to sunlight. The new species is also peculiar in that nymphs to be alates (sexuparae) were found on the upper surfaces of leaves of the host oak only during winter, from December to March or early April, before the bud break of the oak. Our molecular phylogenetic analysis indicated that the new species is closely related to Dermaphis spp., therefore it was placed in the genus. The analysis incidentally indicated that “Dinipponaphis” autumna, a monoecious species forming galls on Distylium racemosum, was included in the clade of the genus Dermaphis, and therefore it was transferred to this genus.  相似文献   

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One new kinorhynch genus and species and one new species from the genus Zelinkaderes are described from sandy sediment off Fort Pierce, Florida. The new genus and species, Tubulideres seminoli gen. et sp. nov. is characterized by the presence of the first trunk segment consisting of a closed ring, the second segment of a bent tergal plate with a midventral articulation and the following nine segments consisting of a tergal and two sternal plates. Cuspidate spines are not present, but flexible tubules are located on several segments, and in particular concentrated on the ventral side of the second segment. Middorsal spines are present on all trunk segments and are alternatingly offset to a position slightly lateral to the middorsal line. Zelinkaderes brightae nov. sp. is characterized by its spine formula in having middorsal spines on trunk segments 4, 6 and 8–11, lateroventral acicular spines on segment 2, lateral accessory cuspidate spines on segments 2 and 8, ventrolateral cuspidate spines on segments 4–6 and 9, lateroventral acicular spines present on segments 8 and 9, and midterminal, lateral terminal and lateral terminal accessory spines on segment 11. The spine formula of Z. brightae nov. sp. places it in a position in between Z. submersus and a clade consisting of Z. klepali and Z. floridensis. The new findings on Z. brightae nov. sp. have led us to propose an emended diagnosis for the genus.  相似文献   

12.
The insects that feed on the related plant families Apocynaceae and Asclepiadaceae (here collectively termed “milkweeds”) comprise a “component community” of highly specialized, distinctive lineages of species that frequently sequester toxic cardiac glycosides from their host plants for defense against predators and are thus often aposematic, advertising their consequent unpalatability. Such sets of specialized lineages provide opportunities for comparative studies of the rate of adaptation, diversification, and habitat-related effects on molecular evolution. The cerambycid genus Tetraopes is the most diverse of the new world milkweed herbivores and the species are generally host specific, being restricted to single, different species of Asclepias, more often so than most other milkweed insects. Previous work revealed correspondence between the phylogeny of these beetles and that of their hosts. The present study provides analyses of near-complete DNA sequences for Tetraopes and relatives that are used to establish a molecular clock and temporal framework for Tetraopes evolution with their milkweed hosts.  相似文献   

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We investigate an organism that closely resembles the nonphotosynthetic dinoflagellate “Gymnodinium elongatum” Hope 1954 using EM and molecular methods. Cells are 20–35 μm long, 10 μm wide, biconical, transparent, and have a faint broad girdle. Thecal plates are thin but present (plate formula Po Pi CP 3′ 1–2A 5″ 3C 6S 4? 3″″). With the exception of one feature, the presence of three antapical plates, the amphiesmal arrangement of this species is consistent with that of the order Peridiniales, family Podolampaceae; it is not at all consistent with the characteristics of the genus Gymnodinium. On the basis of these ultrastructural findings, we establish a new genus, Lessardia, and a new species, Lessardia elongata Saldarriaga et Taylor. Molecular phylogenetic analyses were performed using the small subunit rRNA genes of L. elongata as well as Roscoffia capitata, a member of a genus of uncertain systematic position that has been postulated to be related to the Podolampaceae. These analyses place Lessardia and Roscoffia as sister lineages within the so‐called GPP complex. Thecal plate arrangements led us to expand the family Podolampaceae to include the genus Lessardia and, in combination with new molecular results, to propose a close relationship between the Podolampaceae and Roscoffia. Within this lineage, Lessardia and Roscoffia appear to have retained a number of ancestral characters: Roscoffia still has a well‐developed cingulum, a feature absent in all members of the Podolampaceae, and Lessardia has more than one antapical plate, a character reminiscent of some members of the family Protoperidiniaceae.  相似文献   

15.
《Journal of bryology》2013,35(3):161-164
Abstract

The genus Lobatiriccardia Furuki is reported as new to China, from the Dulong River valley, Gaoligong Shan range, Yunnan Province and this material is described as a new species endemic to China, Lobatiriccardia yunnanensis Furuki & D.G. Long, the fifth known species in the genus. The differences between the new species and the other members of the genus are enumerated, along with a key to all known species of Lobatiriccardia.  相似文献   

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Hartmannellid amoebae are an unnatural assemblage of amoeboid organisms that are morphologically difficult to discern from one another. In molecular phylogenetic trees of the nuclear‐encoded small subunit rDNA, they occupy at least five lineages within Tubulinea, a well‐supported clade in Amoebozoa. The polyphyletic nature of the hartmannellids has led to many taxonomic problems, in particular paraphyletic genera. Recent taxonomic revisions have alleviated some of the problems. However, the genus Saccamoeba is paraphyletic and is still in need of revision as it currently occupies two distinct lineages. Here, we report a new clade on the tree of Tubulinea, which we infer represents a novel genus that we name Ptolemeba n. gen. This genus subsumes a clade of hartmannellid amoebae that were previously considered in the genus Saccamoeba, but whose mitochondrial morphology is distinct from Saccamoeba. In accordance with previous research, we formalize the clade as distinct from Saccamoeba. Transmission electron microscopy of our isolates illustrate that both molecularly discrete species can be further differentiated by their unique mitochondrial cristal morphology.  相似文献   

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Paramecium schewiakoffi sp. nov. is described from a pond in Shanghai, China. It is a freshwater species belonging to the “aurelia” subgroup of the genus. It is of similar size and shape to P. jenningsi, but has a single large micronucleus of the “chromosomal” morphological type, while P. jenningsi has two smaller micronuclei. The general morphology, morphometric characteristics and nuclear reorganization pattern, a random amplified polymorphic DNA (RAPD) fingerprint pattern, and the small subunit rRNA gene sequence are presented for the species. Comparison of P. schewiakoffi with the other species of Paramecium indicates that it is a valid new species of the genus. Geographical locations reported for many Paramecium species do not support the theory that all ciliates have a cosmopolitan distribution. It is proposed that, in an extension of Jankowski's earlier suggestion, the genus Paramecium should be subdivided into four subgenera: Chloroparamecium, Helianter, Cypriostomum and Paramecium, on the basis of morphometric, biological and molecular differences.  相似文献   

20.
Parasitoids of the genus Horismenus (Hymenoptera: Eulophidae) are the main natural enemies of bruchid beetles that feed on several species of Phaseolus beans. Samples of Horismenus depressus, H. missouriensis and H. butcheri were collected from seeds of three Phaseolus species throughout Mexico to examine the impact of plant variability on the genetic structure of parasitoid populations. For this purpose, six microsatellite loci were isolated and characterized. These loci are of great interest in understanding the taxonomy of the genus Horismenus, the most important Eulophid genus in the Neotropics.  相似文献   

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