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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Taxonomic, genetic and ecological studies in Helophorus F. (Coleoptera: Hydrophilidae)

Angus, R. B. January 1969 (has links)
No description available.
2

Wolbachia distribution in selected beetle taxa characterized by PCR screens and MLST data

Sontowski, Rebekka, Bernhard, Detlef, Bleidorn, Christoph, Schlegel, Martin, Gerth, Michael 27 October 2015 (has links) (PDF)
Wolbachia (Alphaproteobacteria) is an inherited endosymbiont of arthropods and filarial nematodes and was reported to be widespread across insect taxa. While Wolbachia’s effects on host biology are not understood from most of these hosts, known Wolbachia-induced phenotypes cover a spectrum from obligate beneficial mutualism to reproductive manipulations and pathogenicity. Interestingly, data on Wolbachia within the most species-rich order of arthropods, the Coleoptera (beetles), are scarce. Therefore, we screened 128 species from seven beetle families (Buprestidae, Hydraenidae, Dytiscidae, Hydrophilidae, Gyrinidae, Haliplidae, and Noteridae) for the presence of Wolbachia. Our data show that, contrary to previous estimations, Wolbachia frequencies in beetles (31% overall) are comparable to the ones in other insects. In addition, we used Wolbachia MLST data and host phylogeny to explore the evolutionary history of Wolbachia strains from Hydraenidae, an aquatic lineage of beetles. Our data suggest that Wolbachia from Hydraenidae might be largely host genus specific and that Wolbachia strain phylogeny is not independent to that of its hosts. As this contrasts with most terrestrial Wolbachia–arthropod systems, one potential conclusion is that aquatic lifestyle of hosts may result in Wolbachia distribution patterns distinct from those of terrestrial hosts. Our data thus provide both insights into Wolbachia distribution among beetles in general and a first glimpse of Wolbachia distribution patterns among aquatic host lineages.
3

Wolbachia distribution in selected beetle taxa characterized by PCR screens and MLST data

Sontowski, Rebekka, Bernhard, Detlef, Bleidorn, Christoph, Schlegel, Martin, Gerth, Michael January 2015 (has links)
Wolbachia (Alphaproteobacteria) is an inherited endosymbiont of arthropods and filarial nematodes and was reported to be widespread across insect taxa. While Wolbachia’s effects on host biology are not understood from most of these hosts, known Wolbachia-induced phenotypes cover a spectrum from obligate beneficial mutualism to reproductive manipulations and pathogenicity. Interestingly, data on Wolbachia within the most species-rich order of arthropods, the Coleoptera (beetles), are scarce. Therefore, we screened 128 species from seven beetle families (Buprestidae, Hydraenidae, Dytiscidae, Hydrophilidae, Gyrinidae, Haliplidae, and Noteridae) for the presence of Wolbachia. Our data show that, contrary to previous estimations, Wolbachia frequencies in beetles (31% overall) are comparable to the ones in other insects. In addition, we used Wolbachia MLST data and host phylogeny to explore the evolutionary history of Wolbachia strains from Hydraenidae, an aquatic lineage of beetles. Our data suggest that Wolbachia from Hydraenidae might be largely host genus specific and that Wolbachia strain phylogeny is not independent to that of its hosts. As this contrasts with most terrestrial Wolbachia–arthropod systems, one potential conclusion is that aquatic lifestyle of hosts may result in Wolbachia distribution patterns distinct from those of terrestrial hosts. Our data thus provide both insights into Wolbachia distribution among beetles in general and a first glimpse of Wolbachia distribution patterns among aquatic host lineages.
4

Fylogeneze a evoluce habitatových preferencí podčeledí Rygmodinae a Sphaeridiinae (Coleoptera: Hydrophilidae) / Phylogeny and evolution of habitat preferences of the subfamilies Rygmodinae and Sphaeridiinae (Coleoptera: Hydrophilidae)

Sýkora, Vít January 2015 (has links)
Subfamilies Rygmodinae and Sphaeridiinae together form approximately one third of the extant diversity within the family Hydrophilidae (Coleoptera: Polyphaga). Members of both these subfamilies inhabit wide spectrum of aquatic and terrestrial environments including specialized habitats such as phytotelmata, carrion or termite nests. So far, habitat shifts within these subfamilies have been only tested with a limited amount of taxa at the family level. Using a broader sampling and Bayesian and maximum likelihood methods, genus-level molecular phylogenetic analysis and divergence dating were performed. The dataset included 96 taxa, representing all major clades (genus groups) in both subfamilies, sequenced for two mitochondrial and two nuclear genes. A single shift from the aquatic to terrestrial environment in the Middle Jurassic was suggested, thus revealing both subfamilies and all tribes as ancestrally inhabiting decaying plant material and leaf litter. Secondary returns to aquatic habitats were suggested for two lineages of the Rygmodinae and several lineages belonging to tribes Coelostomatini and Megasternini. A single shift to flowers was revealed in the subfamily Rygmodinae. Similarly, single independent shifts to the inquiline lifestyle in tribes Omicrini and Megasternini were revealed. In...
5

Biology and Energetics of Tropisternus Lateralis Nimbatus (SAY) (Coleoptera: Hydrophilidae) in a Playa on the Southern High Plains of Texas and Aquatic Coleoptera Diversity from Seven Playas on the Southern High Plains of Texas

Cook, Robert E. (Robert Edward), 1969- 12 1900 (has links)
A study of the biology of Tropisternus lateralis, a hydrophilid beetle, was conducted during the flood period of a single playa on the Southern High Plains of Texas from early June 1995 through early September 1995. Mechanism of colonization, tolerance/avoidance to drought, larval density, and secondary production were analyzed. T. lateralis colonized playas from surrounding aquatic habitats and avoided drought through aerial dispersion. Once in the playa, larval density increased over time. Secondary production was 1.31 g/m2/.25 yr. In addition, aquatic Coleoptera diversity was studied in seven playas on the Southern High Plains of Texas. A total of twenty three species were identified from the study region. Nine species not reported in playa literature were identified.
6

Taxonomie, fylogeze a fylogeografie vybraných skupin vodních brouků (Coleoptera: Hydrophilidae, Hydraenidae) karibské oblasti / Taxonomy, phylogeny and phylogeografy of selected groups of aquatic beetles (Coleoptera: Hydrophilidae, Hydraenidae) of the Caribbean region

Deler-Hernández, Albert January 2017 (has links)
This thesis is focused in the representatives of beetle families Hydrophilidae and Hydraenidae of West Indies and adjacent regions. It consists of two parts, the phylogenetic part and the systematic part. The phylogenetic part focuses on the hydrophilid genera Phaenonotum and Crenitulus of Greater Antilles: beetles were sampled in all four main islands (Cuba, Hispaniola, Puerto Rico and Jamaica) and analyzed using the combination of molecular and morphological data. The genus Phaenonotum contains four single-island endemics, of which those from Cuba, Jamaica and Hispaniola are wingless and form a clade that diversified ca. 46 million years ago (Ma) and likely colonized the Caribbean via the GAARlandia land bridge. In contrast, the Puerto Rican endemic and the two remaining non-endemic species colonized the Greater Antilles by over- water dispersal during the Oligocene-Miocene. The analysis of the genus Crenitulus revealed that Greater Antillean species belong to two separate clades: the Crenitulus yunque clade endemic for Cuba and Hispaniola, and the Crenitulus suturalis clade containing specimens from Greater Antilles and from northern America. A detailed revision of the Crenitulus yunque clade using morphology and molecular-based species delimitation recognized 11 species locally endemic for...
7

Měření diverzity koprofágních brouků a jejich půdní aktivity na pastvině / Examination of the diversity and digging activity of dung beetles in pasture

ANDĚL, Tomáš January 2014 (has links)
The survey of the diversity of coprophagous beetles (Scarabaeidae, Geotrupidae, and Hydrophilidae families) and their soil activity took place at two sites in a cattle pasture in southern Bohemia (site A: 49°29'31.720"N, 14°23'44.310"E; site B: 49°29'23.257"N, 14°23'35.964"E; 575 m a. s. l.). Baited pitfall traps with fresh cow dung (1.5 l per trap) were used to capture the beetles. During the survey of the diversity of coprophagous beetle community, a total of 29 species of beetles numbering 1,189 specimens were captured from May to September 2013. Of these, the most numerous were the beetles of the genus Aphodius, who made up 79 % of the total number of captured specimens. In terms of biomass, Geotrupes spiniger (Marsham, 1802) was significant, in that it made up 24 % of the total biomass of all of the captured beetles. This species contributes most to the decomposition of dung in the pasture. The family with the least number of specimens was Hydrophilidae. Beetles from this family made up 19 % of total number. Measurement of soil activity took place repeatedly over the course of 3 weeks, always after one-week measurement of diversity. The most numerous species (A. fimetarius, A. rufus and A. fossor) showed a linear dependence of the abundances in soil-activity traps on the abundances in diversity traps from the precedent capture period. A. sticticus was one of the most numerous species during surveys of diversity (10 %). This species, belonging to the dwellers group, was not recorded in soil-activity traps, however. Large tunnellers were represented mainly by G. spiniger in traps, for which the linear dependence was not possible to confirm.
8

Vliv pastvy v podhorských oblastech na biodiversitu bezobratlých {--} koprofágové / The influence of pasture on biodiversity of invertebrates in sub-mountain localities - coprophagous beetles

SVOBODA, Lukáš January 2010 (has links)
The effect of the pasture management on dung beetle communities was studied on three sites in Šumava Mts. (South and West Bohemia). The intensity of pasturing was different: 78 cattle on the first, 106 on the second and 162 on the third pasture. The beetles were collected using pitfall traps baited by 1.5 litres of fresh cattle dung. The traps were located on each pasture. Altogether 3 traps were used per each pasture. The pitfall traps were exposed in the pasture for 7 days in monthly repetitions from April to October 2008. Totally 8725 specimen and 33 species of beetles were collected. These species belong to families Scarabaeidae,Geotrupidae and Hydrophilidae. The number of species and individuals was evaluated for each pasture, as well as seasonal dynamics and biomass distribution. The results indicate that the more intensive pasturing has the positive effect on the activity of some groups of coprophagous beetles.Other effects of the different pasture management on the beetles were not documented.

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