21 research outputs found

    The genus Myrmica Latreille, 1804 (Hymenoptera: Formicidae) in Romania : distribution of species and key for their identification

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    Genus Myrmica is one of the largest ant genera in Romania with 18 species distributed across the entire country. In the frame of this study we present the distribution data of all Romanian Myrmica species: M. bergi, M. constricta, M. gallienii, M. hellenica, M. lobicornis, M. lonae, M. karavajevi, M. rubra, M. ruginodis, M. rugulosa, M. sabuleti, M. salina, M. scabrinodis, M. schencki, M. slovaca, M. specioides, M. sulcinodis and M. vandeli. Four species are reported for the first time in the Romanian fauna: M. bergi, M. constricta, M. gallienii and M. karavajevi, while the occurrence of several species is probable. These species are listed separately. In addition, a key to the worker caste of Myrmica (with the use of male characters for some species) is provided, including species with likely occurrence in Romania

    Distribution of the myrmecoparasitic fungus Rickia wasmannii (Ascomycota: Laboulbeniales) across colonies, individuals, and body parts of Myrmica scabrinodis

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    The ant species Myrmica scabrinodis plays a markedly important ecological role through much of the humid grasslands of Eurasia. It hosts a species-rich community of pathogens and parasites, including Rickia wasmannii, an enigmatic member of entomoparasitic laboulbenialean fungi. This study provides a descriptive ecology of R. wasmannii by characterizing its prevalence and distribution across several hierarchical levels: colonies, individuals, and anatomic body parts. Infections were restricted to a single ant species, Myrmica scabrinodis, and infected colonies occurred predominantly in wet habitats. Infections tended to be highly prevalent within infected colonies, often reaching 100% sample prevalence among workers. Individual infections exhibited an aggregated distribution typical to host-parasite systems. Workers from the aboveground part of nests (presumably older ones acting as foragers) were more infected than those from the belowground part. Fungal thalli could be found all over the body of the hosts, the head and the abdomen being the most infected parts of the body. The fungi’s distribution among host body parts statistically differed between low versus high-intensity infections: the initial dominance of the head decreased with advancing infection. These findings may provide baseline data for future comparative or monitoring studies

    Shape tailoring of AgBr microstructures: effect of the cations of different bromide sources and applied surfactants

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    Investigations regarding AgBr-based photocatalysts came to the center of attention due to their high photosensitivity. The present research focuses on the systematic investigation regarding the effect of different alkali metal cation radii and surfactants/capping agents applied during the synthesis of silver-halides. Their morpho-structural and optical properties were determined via X-ray diffractometry, diffuse reflectance spectroscopy, scanning electron microscopy, infrared spectroscopy, and contact angle measurements. The semiconductors' photocatalytic activities were investigated using methyl orange as the model contaminant under visible light irradiation. The correlation between the photocatalytic activity and the obtained optical and morpho-structural properties was analyzed using generalized linear models. Moreover, since the (photo)stability of Ag-based photoactive materials is a crucial issue, the stability of catalysts was also investigated after the degradation process. It was concluded that (i) the photoactivity of the samples could be fine-tuned using different precursors and surfactants, (ii) the as-obtained AgBr microcrystals were transformed into other Ag-containing composites during/after the degradation, and (iii) elemental bromide did not form during the degradation process. Thus, the proposed mechanisms in the literature (for the degradation of MO using AgBr) must be reconsidered

    Adult population ecology and egg laying strategy in the ‘cruciata’ ecotype of the endangered butterfly Maculinea alcon (Lepidoptera: Lycaenidae)

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    Population dynamics studies in insects mostly focus on a specific life stage of a species and seldom consider different stages. In the framework of our research we studied the population demography of a protected Maculinea alcon 'cruciata' population and the factors that could influence the distribution of eggs. The results of the markrecapture survey showed a relatively short flight period between mid-June and midJuly with clearly marked early peak period. Unlike in many other butterflies, proterandry was not strong. The total population of M. alcon 'cruciata' was estimated at 699 individuals. The survival rate, and consequently the average life span, was relatively low. Generally, males proved to be more mobile than females. Eggs showed a highly aggregated pattern, and egg numbers was positively related to general shoot size, while the number of flower buds and the features of the surrounding vegetation did not display any effect on egg laying. Based on our findings the studied population appears viable, but specific management techniques could ensure optimal conditions for egg laying in this protected butterfly

    Host plant preference in the protected myrmecophilous Transylvanian Blue (Pseudophilotes bavius hungarica) butterfly (Lepidoptera: Lycaenidae) and its relationship with potential ant partners

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    When selecting specifc host plants, caterpillars of many lycaenid butterflies, such as the protected Pseudophilotes bavius hungarica, are known to engage in various interactions with ants, which help them survive. Although P. bavius is a protected species, data about its host plant selection is very scarce, and little information is available on its myrmecophilous relationships. Our aim was to identify the host plant characteristics that determine the occurrence of the caterpillar and to clarify the specifcity of its myrmecophily. We conducted a series of feld surveys regarding host plant characteristics. Laboratory experiments were carried out to investigate the nature of interactions between the caterpillar and its potential ant partners. Control experiments involving non-visiting ants were also performed. On the basis of our fndings, the physical characteristics of host plants do not seem to influence host plant choice, but the absence of aphids and the presence of different ant species proved important. According to the results of behavioural assays, neutral reactions to the caterpillars were recorded in the case of ant species that regularly visited the host plant (Lasius paralienus, Camponotus aethiops), in contrast to Tapinoma subboreale, which was not observed at all on the host plants and which behaved aggressively towards the larvae. Therefore, the caterpillar is expected to show a certain ant host selectivity. The study constitutes an essential contribution to our knowledge of the natural history of a protected butterfly species, which can be used as a basis for more appropriate management strategies, while also shedding light on aspects of myrmecophilous relationships in Lycaenidae in general
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