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1.
The scolytid ambrosia beetles Xyleborus monographus and X. dryographus were investigated to identify their nutritional ambrosia fungi. The examination of the oral mycetangia of the beetles, the specialized organs for fungal transport, revealed the dominant occurrence of Raffaelea montetyi, a fungus that was also predominant in the beetle tunnels in the immediate vicinity of the feeding larvae. R. montetyi was previously known only as the ambrosia fungus of the platypodid ambrosia beetle, Platypus cylindrus. These beetle species inhabit the same habitat, mainly trunks of oaks in the Western Palaeartic. The possibility of an exchange of the symbiotic fungus between the ambrosia beetles within their common breeding place is discussed. Consequently, the previous hypothesis of a species-specific association of a single ambrosia fungus with a single beetle species is questioned. A phylogenetic analysis based on DNA sequences classified R. montetyi within the Ophiostomatales of the ascomycetes. The investigation of conidiogenesis of R. montetyi by SEM supported this taxonomic placement and showed the development of the conidia by annellidic percurrent proliferation, identical to the conidiogenesis reported for many anamorph states of the Ophiostomatales.  相似文献   

2.
The species composition and abundance of phoretic mites of the bark beetle Pityokteines curvidens caught in pheromone traps were investigated in Croatia. The P. curvidens trapping programs have been in an experimental phase in Croatia since 2004 as a possible monitoring and control system. The trapping program also permits the opportunity to sample phoretic mites found associated with the beetles. Beetles were caught using Curviwit pheromones in Theysohn traps placed in the Litorić region of Croatia. A total of 12 mite species were recovered, including Schizostethus simulatrix, Dendrolaelaps quadrisetus, Histiostoma piceae, H. cf. varia, Paraleius leontonychus, Pleuronectocelaeno barbara, Tarsonemus minimax, Trichouropoda lamellosa, Uroobovella ipidis, Schwiebea sp., Phauloppia lucorum and Dolicheremaeus dorni. Five species, Pl. barbara, Schwiebea sp., H. cf. varia, Ph. lucorum and Do. dorni, are identified for the first time in association with P. curvidens. These findings increase the number of mite species known to be phoretic on P. curvidens from 11 to 16. The present study also increases the number of known mite associates of Pityokteines spp. from 14 to 18.  相似文献   

3.
Bark beetles (Curculionidae: Scolytinae) feed on the xylem and phloem of their host, which are composed of structural carbohydrates and organic compounds that are not easily degraded by the insects. Some of these compounds might be hydrolyzed by digestive enzymes produced by microbes present in the gut of these insects. In this study, we evaluated the enzymatic capacity of bacteria (Acinetobacter lwoffii, Arthrobacter sp., Pseudomonas putida, Pseudomonas azotoformans, and Rahnella sp.) and yeasts (Candida piceae, Candida oregonensis, Cyberlindnera americana, Zygoascus sp., and Rhodotorula mucilaginosa) isolated from the Dendroctonus rhizophagus gut to hydrolyze cellulose, xylan, pectin, starch, lipids, and esters. All isolates, with the exception of C. piceae, showed lipolytic activity. Furthermore, P. putida, P. azotoformans, C. americana, C. piceae, and R. mucilaginosa presented amylolytic activity. Esterase activity was shown by A. lwoffii, P. azotoformans, and Rahnella sp. Cellulolytic and xylanolytic activities were present only in Arthrobacter sp. and P. azotoformans. The pectinolytic activity was not recorded in any isolate. This is the first study to provide evidence on the capacity of microbes associated with the D. rhizophagus gut to hydrolyze specific substrates, which might cover part of the nutritional requirements for the development, fitness, and survival of these insects.  相似文献   

4.
An exotic invasive pest of pines, the red turpentine beetle, Dendroctonus valens LeConte (Scolytidae) (RTB), was first detected in Shanxi Province, northern China, in 1998 and started causing widespread tree mortality there in 1999. This outbreak continues and has spread to three adjacent provinces, causing unprecedented tree mortality. Although it is considered a minor pest of pines in North America, RTB has proven to be an aggressive and destructive pest of Pinus tabuliformis, China’s most widely planted pine species. The bionomics and occurrence, distribution, response to host volatiles, and host preference of this pine beetle in China are compared with what is known of the beetle in its native range in North America. Factors likely contributing to D. valens success in China and control of the beetle outbreak are discussed. (−)-β-pinene was shown to be the most attractive host volatile for D. valens from the Sierra Nevada of California, whereas 3-(+)-carene is the most attractive host volatile for beetles in China. Monocultures of Pinus tabuliformis, several consecutive years of drought conditions and warm winters have apparently factored D. valens invasion and establishment in China.  相似文献   

5.
The merkli group of the weevil genus Plinthus is revised. Plinthus navarsati Davidian et Savitsky, sp. n. is described from Northeastern Turkey. New data on the morphology and geographical distribution of P. merkli Frivaldszki, 1894, P. cavazzutii Meregalli, 1985, and P. latipennis Meregalli, 1985 are given, with a key to all the four species of the merkli group.  相似文献   

6.
The taxonomic composition of the subgenus Caucasoplinthus Davidian, 1995 is revised. The immunis and granulosus groups are downgraded to subgroups of the silphoides and fallax groups, respectively; the voriseki subgroup is transferred from the fallax to the fausti group. Plinthus attilai Davidian et Savitsky, sp. n. and P. ljudae Davidian et Savitsky, sp. n. are described from Turkey and Abkhazia, respectively. New data on the taxonomy, distribution, and ecology of some little-known species are presented. The following new synonymy is established: Molytes vittatus Motschulsky, 1839 (= Meleus irroratus Reitter, 1884, syn. n., = Meleus faldermanni Faust, 1884, syn. n., = Meleus difficilis Faust, 1884, syn. n.).  相似文献   

7.
8.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

9.
Xylosandrus mutilatus is an Asian ambrosia beetle that has recently established in Mississippi, Texas, Alabama, and possibly Florida, USA. We investigated the fungi associated with the mycangia (specialized fungus-transporting structures) of X. mutilatus in Mississippi. Mycangia consistently yielded an Ambrosiella sp. which was subsequently found to be closely related to, but distinct from, other Ambrosiella species affiliated with Ceratocystis. This Ambrosiella is described herein as Ambrosiella beaveri sp. nov. Also isolated were Geosmithia lavendula, G. obscura, and a yeast, Candida homelintoma. It is likely Ambrosiella beaveri was introduced along with the beetle into North America.  相似文献   

10.
The effects of feeding on root by the larvae and three types of Momordica cochinchinensis Spreng (Cucubitaceae) leaves (young, mature and senescent) by the adults of Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) were studied under laboratory conditions. Total larval developmental time was 19.7 ± 0.2 days by feeding on young roots. Adult males lived for 28.4 ± 1, 65.7 ± 1.1 and 22.8 ± 1.3 days on young, mature and senescent leaves, respectively; whilst adult females lived for 34.3 ± 1.2, 68.5 ± 0.9 and 26.4 ± 1.4 days on young, mature and senescent leaves, respectively. Fecundity was highest in mature leaves fed insects (202.2 ± 10.6). Total carbohydrate, protein, lipid, nitrogen and amino acid were much higher in root followed by mature leaves than young and senescent leaves. Moisture content was highest in mature leaves than the roots, young and senescent leaves. Phenols were greatest in young leaves followed by mature leaves and least in senescent leaves and roots of the said plant. Flavonols were higher in young leaves and least in root. These results suggest that A. foveicollis adults perform better on mature leaves than young and senescent leaves for their nutrition.  相似文献   

11.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.  相似文献   

12.
The granulosus subgroup of Plinthus is revised. Plinthus frivaldszkyi Davidian et Savitsky, sp. n. and P. mananauricus Davidian et Savitsky, sp. n. from the Caucasus are described. New data on the morphology and geographic distribution of P. granulosus Reitter, 1884, P. abdurakhmanovi Davidian, 1995, and P. kataevi Davidian, 1992 and a key to five species of the granulosus subgroup are presented.  相似文献   

13.
Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.  相似文献   

14.
Single (unpaired) vegetative cells of freshwater pennate diatom Neidium cf. ampliatum differentiated into gametangia and produced a single zygote (auxospore) via a pedogamic process. The gametic nuclei fused after auxospore expansion had begun. The auxospore expanded in parallel to the apical axis of the gametangium.  相似文献   

15.
A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.  相似文献   

16.
17.
As partial results of a long-term project for the revision of the supraspecific classification of the American Melolonthini, using phylogenetic methods, interesting information on the relationships between the subgeneric groups of Phyllophaga Harris proposed by Saylor were obtained. The genus Listrochelus was described by Blanchard in 1851. However, in 1940, Saylor reduced it as a subgenus of Phyllophaga. The objective of the present study is to confirm the monophyly of Listrochelus by means of a phylogenetic analysis. A total of 132 species were analyzed; 31 species of them belong to Listrochelus, 76 are from other groups of Phyllophaga, and 25 species are from the outgroup. A morphological matrix with 281 characters was codified. A traditional search with 1000 iterations was performed in TNT. Branch support was investigated using the bootstrap method. Parsimony analysis resulted in ten equally parsimonious trees. The topology obtained in the strict consensus tree shows that the limits of Listrochelus are very clear (bootstrap 99%), supported by five synapomorphies and a combination of eight character states that are not exclusive to the group. Based on the hypothesis obtained, the restitution of the genus Listrochelus is proposed.  相似文献   

18.
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.  相似文献   

19.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.  相似文献   

20.
Dendroctonus valens is an invasive pest in coniferous forests of northern China. It was suspected of being responsible for the death of more than three million Pinus tabuliformis trees. The present study sought to identify the ophiostomatoid fungi associated with D. valens in northern China and understand the possible role of these fungi in the pine decline. On the basis of morphology, physiology, mating compatibility and phylogenetic analyses of multiple DNA sequences, seven species of ophiostomatoid fungi were isolated from and around D. valens galleries: Leptographium alethinum, Grosmannia koreana (teleomorph of L. koreanum), L. procerum, L. sinoprocerum, L. truncatum, Pesotum aureum and P. pini. All have been recorded for the first time in China. Among them, the occurrence of the dominant species L. procerum is positively linked to attack intensities of D. valens. The pathogenicity of four species (L. koreanum, L. procerum, L. sinoprocerum and L. truncatum) was tested on mature P. tabuliformis trees by stem inoculation. All inoculated strains caused significant necrotic lesions on the inner bark. However, L. koreanum and L. truncatum induced more extensive lesions than L. procerum and L. sinoprocerum. Their association with D. valens and the P. tabuliformis decline is discussed.  相似文献   

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