Genom att extrahera, amplifiera och sekvensera DNA från ben av trollsländeartenLeucorrhinia dubia ämnar jag få en inblick i hur arter invandrat till Skandinavien sedan densenaste istiden och en mindre inblick i den genetiska variationen av arten i Skandinavien. Fördetta valdes en mitokondrisk gen (cytochrome c oxidase subunit I, COI) och en nukleär (28sribosomal RNA subunit D7). Totalt blev det 112 sekvenser (55 av COI genen och 57 för D7genen) från 10 olika populationer i Sverige, Norge och Finland som delade upp sig i tvåseparata klader med lite variation mellan individerna i de fylogenetiska träden. Utseendet påträden skulle kunna tyda på att L. dubia invandrat till Skandinavien flera gånger och kansketill och med från flera refuger, en i söder i Centraleuropa och en i öster i närheten avKaukasus. Trädens utseende tyder även på att arten egentligen är flera, kanske kryptiska arter.

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The change of land use to include more urban areas is considered one of the main threats to biodiversity worldwide. Urban stormwater retention ponds have been built to collect storm runoff intensified by the increase in impervious surfaces. Although subject to environmental pressures like habitat degradation and pollution, these stormwater retention ponds are diversity hotspots by providing habitat for several aquatic and semi-aquatic species, including dragonflies. Previous research in Denton, Texas, has demonstrated that urban stormwater retention ponds support high taxa richness of adult dragonflies, but not for the aquatic nymphs. The current study builds on what we have seen by focusing on the immature aquatic stage as nymphs using secondary production of dominant dragonfly taxa and community structure to compare ecosystem function in three ponds with differing intensities of land use. Comparing communities and secondary production resulted in specific conductivity, dissolved oxygen, complex vegetation, and abundance explaining the differences between dragonfly communities. Secondary production was dependent on abundance which followed the intensity of urban land use surrounding the pond. This study supports that urban land use does have an effect on the functioning of the ponds and shows the importance of studying the communities over a year to get a clearer picture of what is happening in the ponds.

abstract: One hypothesis for the small size of insects relative to vertebrates, and the existence of giant fossil insects, is that atmospheric oxygen levels have constrained body sizes because oxygen delivery would be unable to match the needs of metabolically active tissues in larger insects. This study tested whether oxygen delivery becomes more challenging for larger insects by measuring the oxygen-sensitivity of flight metabolic rates and behavior during hovering for 11 different species of dragonflies that range in mass by an order of magnitude. Animals were flown in 7 different oxygen concentrations ranging from 30% to 2.5% to assess the sensitivity of their behavior and flight metabolic rates to oxygen. I also assessed the oxygen-sensitivity of flight in low-density air (nitrogen replaced with helium), to increase the metabolic demands of hovering flight. Lowered atmosphere densities did induce higher metabolic rates. Flight behaviors but not flight metabolic rates were highly oxygen-sensitive. A significant interaction between oxygen and mass was found for total flight time, with larger dragonflies varying flight time more in response to atmospheric oxygen. This study provides some support for the hypothesis that larger insects are more challenged in oxygen delivery, as predicted by the oxygen limitation hypothesis for insect gigantism in the Paleozoic. / Dissertation/Thesis / M.S. Biology 2011

Odonatopera exhibit a wide diversity of morphologies for an ancient group of winged insects. A morphological matrix of 463 characters is compiled for 347 extant and fossil representatives used in parsimony analyses, implemented in TNT, to document arrangements of taxonomic groups above the family level. Missing data and other challenges approaches implemented and interpretation of the results. We employ a novel approach to testing monophyly relative to quantities of missing data for each taxon. Phylogenetic reconstructions recover patterns of monophyly and trends based on missing data. We discuss the implications of our findings on missing data as well as limitations to systematics in general for Odonatoptera.

A functional understanding of how phenotypic traits may affect growth, reproduction and survival is necessary to understand their ecological and evolutionary consequences. Larval dragonflies (Odonata: Anisoptera) swim using jet propulsion, likely controlled by abdominal traits and perhaps to escape fish predators. I investigated whether abdominal morphology explains swimming performance and if either explains the distribution of larvae among ponds that vary in predation risk. I recorded and measured the swimming performance of dragonflies responding to simulated attack and tested relationships with abdominal traits expected to influence jet thrust force generation. Variation in swimming performance was explained by abdomen dry weight, ventral surface area, and abdominal segment 10 width across genera as hypothesized. High-performance dragonflies were more likely to occur in ponds containing predatory fish. This is the first investigation of the morphology responsible for jet propulsion, and the relationship between swimming performance and larval dragonfly ecology.

Micro Air Vehicles (MAV’s) have small size and extreme maneuverability which makes them ideal for surveillance. Propulsion mechanisms include propellers, rotors, and flapping airfoils. Flapping motions, along with biologically-inspired wing profiles, are of interest due to their use of natural physics. Corrugated airfoil structures appears to have poor aerodynamic performance at higher Reynolds numbers, but serve well at Re<10,000. Understanding flow structures around corrugated profiles and comparing them to a standard airfoil will aid in understanding how these corrugated profiles perform well and have been adopted by some of nature’s most acrobatic flyers. Motivation for this investigation is to compare static flow visualizations of corrugated profiles to a standard National Advisory Committee for Aeronautics (NACA) airfoil from low to high angles of attack and further observe flow structure development of a pitching and plunging flat plate at a Re<10,000 and a Strouhal number relevant to natural fliers. The static visualization was conducted at Re=1,000 with a NACA 0012 airfoil and two corrugated models. The Pitch and Plunge Fixture (PPF) developed was constructed by simplifying flapping wings as a two degree of freedom motion in plunge (translation) and pitch (rotation). Results obtained from the PPF were compared with a numerical simulation.

Communication among animals often relies on visible signals and the ability to compatibly perceive them. Correct signal perception is especially important for animals with male sexual selection. In my master's thesis, I am addressing the issue of how does a male golden-ringed dragonfly (Cordulegaster boltonii) recognize a female of the same kind and therefore, what is the main trigger of copulation behavior. Dragonflies display a wide variety of colors and possess very big eyes. These characteristics already suggest that they are very liable on color vision (Futahashi, 2015). Their sight is perfectly developed within the insect class and plays the most important role in the imagines in comparison to other senses. The ability to orient themselves using sight is not just important for orientation in space, nonetheless it is important for reproduction. Since golden-ringed dragonflies do not demonstrate visible color dimorphism, previous as well as my research suggests that the key role for female reconnaissance is primarily their typical movement above water surface during oviposition. In my research, I presented variable types of lure - females to male golden-ringed dragonflies and I observed what is the foremost trigger of reproduction behavior in the males. Besides the above mentioned female...

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