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The articulation of insect wings
Křečková, Adéla ; Prokop, Jakub (advisor) ; Král, David (referee)
The origin of wings is one of the most important innovation in insect evolution which opened new niches due to unique flight abilities. Movement of the wing is provided by the specific wing base structures consisted of the articular sclerites and the flight muscles. In general there are three main types of basal articulation in insects. Neopteran articulation represents presumably the ancetral type from which the others are derived. These are found in two palaeopteran orders Ephemeroptera and Odonata. Palaeoptera differs from Neoptera by incapability of the wing flexion over the abdomen. This incapability is caused by their specific articulation of the wings to the thorax. Various arrangements of wing sclerites among insect groups have significance in respect of phylogeny and thus represent number of important morphological characters. These are therefore used in higher systematics of extant groups as well as scarcely in their extinct fossil relatives. In the present thesis I introduce the review of literature sources concerning the main types of the wing articulation, their homologies and their significance in respect of higher insect phylogeny.
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Reproductive behaviour of males of Golden-ringed Dragonfly (Cordulegaster boltonii)
Dubcová, Dominika ; Černý, Martin (advisor) ; Dolný, Aleš (referee)
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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Spatial orientation in Odonata
Hupková, Lenka ; Černý, Martin (advisor) ; Sacherová, Veronika (referee)
The aim of this review is to evaluate and sum up an existing knowledge about spatial orientation of dragonflies, particularly at small and medium spatial scales. I deal mostly with orientation by horizontally polarized light, which belongs among the most explored field of orientation of Odonata; beside that I explore an orientation of dragonflies during the habitat selection and within their home ranges / territories. Regarding the latter, I pay an attention namely to the function of spatial landmarks, which has not been yet fully explored and offers a lot of opportunities for further research (like many other orientation topics of Odonata). I also briefly discuss an orientation of dragonflies during migrations. Besides the visual orientation I mention the orientation by olfactory sense, tough Odonata was concerned anosmic for a long time. Key words: spatial orientation, visual orientation, dragonflies, Odonata, landmarks
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Variation in dragonfly wing venation with application of geometric morphometrics (Insecta: Odonata)
Přibylová, Petra ; Prokop, Jakub (advisor) ; Růžička, Jan (referee)
The pattern of wing venation in dragonflies (Odonata) bears a set of characters commonly used in systematics. The aim of this thesis is to identify the wing venation variability of dragonflies by various methods of geometric morphometric. The wing venation variability was examined on the level of suborder, family, species and also in respect to dimorphism through the principal component analysis (PCA), redundancy analysis (RDA) and centroid size. Data set consisting of images of 46 dragonfly species, belonging to 43 genera and 24 families was obtained from institutional entomological collections. The research carried out that Zygoptera have a large variety of wing contours. The wing venation variability of Epiprocta is shown primarily in the costa and node area. Between sexes there is no noticeable difference in shape or structure of the wing. The ratio between wing length and width and the pterostigma shape is dependent on dragonfly body size. Key words: Odonatoptera, Odonata, Epiprocta, Zygoptera, wing venation, variability, geometric morphometrics
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Migrations of dragonflies and damselflies (Odonata)
Hančíková, Barbora ; Černý, Martin (advisor) ; Waldhauser, Martin (referee)
This study is aimed at the phenomenon of migration, which is not still fully explored and which, by different circumstances, undergo several species of dragonflies (Odonata). Only for a few species from several tens of migrants generally, their migration route and strategies are explored. These case studies are described and I am also dealing with those species of dragonflies for which migration is not fully explored, and I am pointing out the other possible fields of research. One of the aims of my work is the comparison of different attributes and strategies of migration in dragonflies with other migrants from insect as well as the migratory birds.
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Factors affecting dragonfly species composition in newly created pools and assessment of invertebrate predation on pools zooplankton
Dobiáš, Jakub ; Černý, Martin (advisor) ; Harabiš, Filip (referee)
To identify and quantify the influence of physico-chemical, biotic and geographic factors on the population of dragonflies (Odonata) is an essential tool for research of their ecology. The aim of this study was to 1) assess how these factors influence species richness, diversity and spatial distribution of dragonflies in 42 newly constructed or renewed pools located in the Kokořínsko Protected Landscape Area, which is characterized by two valleys of Liběchovka and Pšovka creeks, low human impact, and a great diversity of small water bodies and 2) use laboratory experiments in order to estimate the relationship between large predatory invertebrates of these pools (Aeshna cyanea, Coenagrion puella, Chaoborus crystallinus and Notonecta glauca) and their common prey (Daphnia curvirostris) in an artificial environment with or without aquatic macrophytes. The pools were monitored and sampled between years 2005 and 2006. In total, 23 dragonflies species were found inhabiting these lentic habitats, comprising 11 species belonging to the suborder Zygoptera and 12 species belonging to the suborder Anisoptera, including a rare species Sympetrum depressiusculum (larvae). Most variability in the dragonfly species richness was explained by the size of the water surface area, followed by the location of the pools (inside...
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Impact of agroforestry on dragonflies diversity
Kajzrová, Soňa ; Lojka, Bohdan (advisor)
Tropical rain forests around the world suffer from deforestation, which is caused mainly by small-scale farmers. These farmers largely employ slash-and-burn methods to clear the land for agricultural settlement. Agroforestry systems are widely found in the humid tropics, where they could have great potential to increase the productivity of farming systems and sustain continuous crop production and they are also supposed to conserve biodiversity. As a group of freshwater invertebrates, dragonflies (Odonata) are commonly used as ecological indicators of freshwater ecosystems. The main objective of the study is to assess the impact of land use changes on dragonflies (Odonata) species richness and diversity, namely primary and secondary forest, cocoa agroforest and slash-and-burn agriculture in the Tropical Africa. We hypothesize, that the species richness and diversity of dragonflies decrease with disturbance of the ecosystems, along the land-use changes gradient.
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The effect of ecotones on the overwintering of Winter damselflies (Odonata: Lestidae)
Dolejšová, Lucie ; Harabiš, Filip (advisor) ; Michal, Michal (referee)
Sympecma fusca is a species of winter damselflies with unique life history. The uniqueness of life history is coupled with overwintering in adult life stage in terrestrial environment, which is associated with high mortality rate. Such risk can be reduced by preference for specific habitats. Since terrestrial environment is frequently affected by anthropogenic disturbances, winter damselflies must respond to interventions into their habitat. This thesis focuses mainly on anthropogenic interventions into the habitat of winter damselflies and the impact of such disturbances on the distribution of individuals of species Sympecma fusca. Capture-Mark-Recapture Method was chosen for modelling of population dynamics in selected transects. Data collection took place during the pre-reproductive period within two years. Year-on-year comparison showed a decrease in abundance as well as changes in distribution of individuals in the studied transects. Individuals responded to habitat disturbances by searching for alternative micro-habitats, preferring places unaffected by anthropogenic disturbances. The acquired data indicate that winter damselflies are able to respond actively to environmental changes, nevertheless number of suitable habitats decreased significantly in the given site. This thesis is only a pilot study. Therefore, other reference sites are suggested for further study of anthropogenic influence on the life history of winter damselflies.
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Is there any seasonal differences in terrestrial habitat use in dragonflies?
Hronková, Jana ; Harabiš, Filip (advisor) ; Aleš, Aleš (referee)
Dragonflies (Odonata) passing through several life stages during their life cycle. During metamorphosis between stages, they did not change only morphology, but also habitat preferences. Although they are associated to aquatic environment during larval stage, adults are much more mobile and can utilize the surrounding terrestrial habitats. Adult dragonflies are also involved in to terrestrial food chains. However the relationship, between the quality of terrestrial habitats and the diversity of dragonflies as well as seasonal changes in utilization of these habitats are still not known. This thesis aiming to analyze the influence of seasonality and distance from aquatic habitat on the abundance of dragonflies. Moreover, the differences in fish farming intensity were considered in the analyses. Fieldwork took place during 2015 from May to September. Data from 29 localities of Czech Republic were included. It is not surprising that I found significant influence of seasonality, on the abundance of all species, as well as a negative relationship between dragonfly abundance and distance from water reservoir. Interestingly, it was found, that dragonfly utilization of terrestrial areas around the extensively managed habitats was significantly higher than in habitats around intensively managed ponds. These findings demonstrate the importance of terrestrial habitats for dragonflies, especially those occurring around extensively managed water habitats.
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Ecology of endangered damselfly \kur{Coenagrion ornatum} in post-mining streams in relation to their restoration
TICHÁNEK, Filip
The thesis explores various aspects of ecology of endangered damselfly Coenagrion ornatum, the specialists for lowland headwaters, in post-mining streams of Radovesicka spoil. The first part of thesis is manuscript which has been already submitted in Journal of Insect Conservation. In the first part, we focused on population estimate of the local population using capture-recapture method, and explored its habitat requirements across life stages and spatial scales. In the next part, I assess mobility of the focal species and reveals basic distribution patterns. Finally, the thesis suggest various implications for restoration of post-mining freshwaters and conservation of the studied species.
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