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46 Uppsatser om Damsefly larvae perch - Sida 3 av 4

Höns återhämtning efter stress samt domesticeringens effekter : En biologisk studie med ett lärarperspektiv

Den biologiska studien har visat att värphöns genom domesticeringen förändrat och anpassat sina beteenden till att leva med människor. De har utvecklat en minskad rädsla för människor och en ökad stresstålighet. I denna studie har höns återhämtning efter en stressupplevelse studerats. För att se hur domesticeringen har påverkat återhämtningen jämfördes beteenden mellan raserna White Leghorn och red junglefowl. Frågeställningarna som användes för att undersöka detta var: Hur lång tid tar det innan höns återhämtar sina naturliga beteenden, ej stressrelaterade, efter en stressupplevelse? Finns det några skillnader i återhämtningen beroende av kön eller mellan raserna White Leghorn och red junglefowl? Resultatet visade inte på en specifik tid för återhämtning men på att en tydlig återhämtning förekom.

Plant defensive mechanisms against insect pests

This study has focused on testing the following two hypotheses:? Pest resistant plants have higher levels and/or several different kinds of secondary metabolites. ? Induced defensive systems in resistant plants are activated more rapidly than those of susceptible plants. As a background for the test of the hypotheses a short literature study was performed concerning plant defensive mechanisms in Arabidopsis thaliana.

Inventering av flodpärlmussla i Fylleån norr om Gyltigesjön

Freshwater environments are threatened worldwide, of which many of the species associatedwith freshwater. In 2014, 243 freshwater mussels were on the international Red List. One ofthem is the freshwater pearl mussel, Margaritifera margaritifera, which because of itscomplex life cycle can be counted as an indicator of whether a stream is worth protecting. It's since the early 1900's in decline throughout their range. Sweden is counted as a core area which is why we have not only a national but an international responsibility to conserve the species.

Didaktiska arter

The study intends to find easily recognizable indicator species for water quality in the constructed wetland of Flemingsbergsviken. The study is relevant since indicator species can be difficult to determine for common people. Easily recognizable indicator species could improve dialogue between the scientific community, administrative authorities and the general public. Such species could be used in education systems, associations or in information campaigns. Therefore, I have chosen to refer to these species as didactical species.

Inventering av vecklare i Svenska äppelodlingar

Over the last couple of years, growers, researchers, advisors and plant protection companies have noticed increasing problems with tortricids in Swedish apple orchards. Since the insecticide Gusathion (azinphosmethyl) has been banned (end of 2008; KemI 2008), a further increase of tortricid populations can be expected. In order to get a picture of species composition and population densities among the tortricids, an inventory of seven species, Adoxophyes orana, Archips podana, Archips rosana, Cydia pomonella, Hedya nubiferana, Pandemis heparana and Spilonota ocellana was made in 11 orchards in southern Sweden (Skåne) in 2008. Population densities were estimated by bud sampling (April 20-25), pheromone trapping (May 5-September 22) and assessment of fruit damage (September 9-12). In all orchards A.

Parasite detection in extensively hold Gotland ponies

Horses are herbivores that spend almost all day grazing. While grazing they are infected by different endoparasites through ingestion of infective eggs or larvae on pasture. The most significant equine endoparasites in Sweden are the equine roundworm Parascaris equorum, small (Cyathostominae) and large strongyles (Strongylus spp), the tapeworm Anoplocephala perfoliata and the pinworm Oxyuris equi. For many years have horses been dewormed on regularly basis, which has resulted in the development of resistance to many anthelmintic classes. Because of the problems with resistance it is since 2007 necessary to have a prescription on anthelmintics and faecal sampling is also recommended.

GIS-baserad habitatmodell för mindre hackspett, ett verktyg för att bevara skyddsvärda lövskogar inom Umeälvlandskapet :

Deciduous forests are, according to the National Environmental Quality Objectives, a priority area. Deciduous forests are rich in species and the occurrence of dead wood is an important factor for biodiversity. In order to identify valuable deciduous forests for bio-diversity, conservation needs good analyses and planning tools. Habitat models combined with geographic information systems can be used to study the spatial structure of suitable habitat. The Lesser spotted woodpecker (Dendrocopos minor) has been proposed as an indicator species for deciduous forests, since this species is highly specialized on insect larvae in dead wood and requires large areas of deciduous-rich environments. Many riparian forest with high species richness and high nature conservation values are found along the Ume river in Umeå municipality.

Differences in host plant preferences and olfactory physiology between populations of the moth Spodoptera littoralis established in Egypt and Benin

This study was made to compare and distinguish any differences in olfactory recognition and host plant adaptation between two strains of cotton leaf worm, Spodoptera littoralis. The populations used were established in Egypt and Benin, Africa. The documentation consisted of information about (1) each of the strains development through the larval stage up to pupation on diets of cotton, clover and cowpea. (2) Their oviposition preferences as adults between cotton, clover, cowpea, maize and cabbage. (3) Electroantennographic recordings to quantify any possible responses to plant volatiles. Throughout the diet experiments the larvae from the Benin strain showed significantly a better development between artificial, clover, cowpea and cotton respectively, while the Egypt strain had significance between artificial, cotton and cowpea/clover as diet. Also noted was how the strains substantial development of weight differentiated if fed the cotton diet, followed by the cowpea diet showing that the Benin strain would develop a higher body mass on a cotton diet as well as on a cowpea diet. This trend was however switched once the pupal stage was reached, where the Egyptian strain contained a significantly greater body mass than the Benin strain on the artificial and the Benin strain a greater on cowpea, which suggests that in the end, the Benin strain develops significantly better on cowpea while the Egypt strain develops better on an artificial diet. During the oviposition experiment that both stains showed a clear difference in hierarchy of host plants considered suitable for oviposition, where the Egyptian strain is significantly more attracted to clover than the Benin strain. Also showed with electroantennographic recordings and significant values was the higher sensitivity the Egypt strain had towards (E)2-hexenal, (E/Z)-b-ocimene, (Z)-3-hexenyl acetate, Nonanal, (-)-linalool and ?-myrcene when compared to the responses from the Benin strain..

Gullrisbock (Phytoecia nigricornis) i grus- och sandtäkter i Halland.

This dissertation is done as a preparatory step for the action plan of environmental protection shall issue to preserve the Phytoecia nigricornis in the country when it is red-listed and classified as vulnerable (VU). My task was to investigate the prevalence of the Phytoecia nigricornis in Halland County. They wanted to see if it existed in Halland (Ehnström, 1999). If it did not exist they wanted to know how to improve its habitat.the Phytoecia nigricornis is difficult to inventory because when it is larvae it lives in the roots and lower parts of the trunk of the Solidago Virgaurea plant and the adult beetles only keeps to Solidago Virgaurea by mating and egg laying and larval caterpillars when they hatch (Bily, 1989; Molander, 1999). Often it is overlooked or missed, and one question was whether it existed  in the whole country or only in those parts where it was previously found in, Skåne, Blekinge and Östergötland (Ehnström, 1999).One problem for the Phytoecia nigricornis is that their habitats is declining.

Vivlar på prydnadsbuskar - nya arter eller förändringar i födopreferenser?

During the last couple of years leaf-edge-cuts, typical to Otiorhynchus wingless-weevils, have been discovered on ornamental shrubs, especially Syringa vulgaris lilac and Ligustrum vulgare privet. These plant species have not earlier been attacked by wingless-weevils and because of that, the aim of this study is to see if new species of weevils have been established in Sweden or if the domestic weevils have changed their food preferences. This work also includes a literature study of known weevil species in Sweden and their host plants, and of wingless-weevil species in Europe that could be invasive here. Locations, where damage to previously named plants has been reported, have been examined. The extension and appearances of the damages have been documented in order to study if different weevil species make different types of edge-cuts.

Determination of anthelmintic resistance of Haemonchus contortus to three classes of anthelmintics in a Kenyan sheep flock based on results from faecal egg count reduction test

Haemonchus contortus is the most important bloodsucking gastrointestinal nematode in small ruminants worldwide. It is often controlled by anthelmintics. Even though other methods to control are available, the most efficient way to treat an animal with clinically manifested haemonchosis is to use one of the available broad spectrum anthelmintics: benzimidazoles (BZ), macrocyclic lactones (ML) or imidothiazoles-tetrahydropyromidines or the narrow spectrum drugs salisylanilides or nitrophenols. Anthelmintic resistance (AR) against all groups of anthelmintics in nematode parasites has been reported from many countries, and even multiple AR has been observed. In this study I have investigated the resistance levels to all major classes of broad spectrum anthelmintics in a naturally infected flock of sheep of Red Maasai sheep (RM), Dorper sheep (D) and their offsprings on a research farm in Kenya.

Simulering av översvämningar i Nedre Dalälven

Mosquitoes are found in extremely large numbers in the lower parts of the River Dalälven. In the year 2000 the mosquito nuisance was especially high, resulting in foundation of the Biological mosquito control project. Since 2001 mosquito larvae are controlled by using a biological pesticide BTI (Bacillus thuringiensis ssp israelensis). The mosquito fauna in the area is dominated by flood water mosquitoes, a group of mosquitoes that are very aggressive and form new generations of mosquitoes during every single flooding event during the summer. To be able to efficiently control the mosquitoes it is essential to know the extension and locality of the flooding.

Odour-mediated behaviour in codling moth, Cydia pomonella : do fermentation odours affect the attraction and oviposition behaviour in codling moth?

The codling moth, Cydia pomonella is a common pest in apple orchards and can be found worldwide. Feeding by codling moth larvae can cause a substantial decrease in apple yield. Control methods comprise for example the use of pesticides, viruses and pheromones. As a sustainable control method, pheromones have been successfully applied to disrupt moth mating behaviour. Other behaviours like foraging, search for mating sites or host finding could be potential targets for additional odour-mediated behavioural manipulation but need further investigations of the underlying odour stimuli and behavioural plasticity. Many insects are attracted to the smell of fermenting fruit and associated microorganisms.

Rosenlunds bankar : Erosion och förändring sedan 1960

During the 1960´s and 1970´s the number of grey seals in the Baltic Sea was decreasing rapidly, mostly due to hunting and toxic substances like DDT and PCB. When hunting became less intense and toxic substances decreased in the environment the grey seal population started to increase. Today grey seals are found common in the Baltic Sea and have started to become a big treat and a problem to the fishing industry. The grey seal destroys and enters fishing traps and consumes large quantities of the fish that have been caught.The knowledge of the grey seal, like abundance and food preferences, is today limited. It is also important to define the position of the grey seal in the ecosystem in the Baltic Sea and to be able to predict changes that could occur if the population would rapidly decrease or increase.

Födosammansättning hos gråsäl (Halichoerus grypus) samt test av flotte för insamling av sälfekalier.

During the 1960´s and 1970´s the number of grey seals in the Baltic Sea was decreasing rapidly, mostly due to hunting and toxic substances like DDT and PCB. When hunting became less intense and toxic substances decreased in the environment the grey seal population started to increase. Today grey seals are found common in the Baltic Sea and have started to become a big treat and a problem to the fishing industry. The grey seal destroys and enters fishing traps and consumes large quantities of the fish that have been caught.The knowledge of the grey seal, like abundance and food preferences, is today limited. It is also important to define the position of the grey seal in the ecosystem in the Baltic Sea and to be able to predict changes that could occur if the population would rapidly decrease or increase.

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