Browsing by Author "Stukalyuk, Stanislav"

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    Characteristics of Thermal Processes in Ant Nests Built Under Stones (Hymenoptera: Formicidae)
    (“Charles Darwin” Sapienza University of Rome, Italy, 2022) Stukalyuk, Stanislav; Radchenko, Yury M.
    ENG: Ants prefer to nest under stones. This is due to temperature regimes favorable to the development of ant broods. In this paper, we investigated the influence of stone and ambient parameters on ant nests and created a model of thermal processes in ant nests under stones. The simulation results were compared with temperature measurements. Temperature was measured under 20 stones under different illumination conditions (sun, penumbra and shade) for 3 ant species (Myrmica rubra, Formica cinerea, Lasius niger) in Ukraine from April to August 2021. Stones were categorized as hot, warm and cold. Each stone was checked once a week for the number of workers and brood. Under two stones, tem¬perature was measured using loggers. The number of workers under hot stones in spring increased three weeks earlier than under cold and warm ones. In May-June, the maximum number of workers was recorded under hot stones. In July, the number of ants was minimal under all categories of stones. Larvae appeared under hot stones two weeks earlier than under other categories of stones. In August, the number of pupae under cold and warm stones was greater than under hot ones. Number of larvae and pupae was positively influenced by the diameter of the stone, whereas stone height did not exert an important role. Ants preferred to inhabit nests under large flat stones, which are easily heated in spring and warm the soil under them. Another important characteristic was the location of the stones. The highest brood development was noted in nests under stones in open areas well lit by the sun in the daytime. In summer ants migrated from under hot stones, because soil under it dry and warmed. Stones and their position may be important factors in accelerating the development of brood in colonies of ant species that do not have active thermoregulation.
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    Effect of Urban Habitats on Colony Size of Ants (Hymenoptera, Formicidae). In Memory of Professor A. A. Zakharov (Russian Academy of Sciences, Moscow)
    (Turkish Academic Network and Information Center, 2022) Stukalyuk, Stanislav; Akhmedov, Ascar; Gilev, Alexey; Reshetov, Alexander; Radchenko, Yuri M.; Kosiuk, Nataly
    ENG: Urbanized ecosystems are suitable for the habitat of only a few species of ants, due to conditions caused by human activities. Invasive species of ants have adapted to urbanized ecosystems most successfully. The study of the ant colonies sizes started in Crimea in 2013–2014. In 2019–2021 it was carried out in Ukraine (the Carpathians, Kyiv city, and Kyiv region), in Russia (Rostov-on-Don city and region, and the Urals), and in Uzbekistan (Tashkent city, and tugai forests). The study covers natural (forest, meadow, steppe), suburban (alleys and tree planting) and urban habitats (tree planting along streets and roads, botanical gardens). Our study covers 21 species of ants with trails on forage areas. Nine species were sampled for interspecific comparison of colony sizes. They were collected in at least 2 habitat types within the same geographic region. According to the activity parameter on the trails, the number of foragers and the population of the colony were calculated (using the formula of A. Zakharov). According to our calculations, the maximum colony sizes are typical for invasive species (Crematogaster subdentata, Lasius neglectus, 100–7500 thousand workers) in the urban habitats. Some native species (Dolichoderus quadripunctatus, Formica cinerea) in the urban areas have colonies with 120–350 thousand workers. These values may exceed those for ant species inhabiting natural habitats (30–250 thousand workers). High rates of colony size in the urbanized habitats can be achieved due to availability of food, nesting resources, and the absence of competing ant species.
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    Mixed Colonies of Lasius Umbratus and Lasius Fuliginosus (Hymenoptera, Formicidae): When Superparasitism May Potentially Develop into Coexistence: a Case Study in Ukraine and Moldova
    (Organisation for Conservation and Study of Biodiversity (CSBD) in collaboration with ANeT-India, 2021) Stukalyuk, Stanislav; Radchenko, Yury M.; Gonchar, Oleksiy; Akhmedov, Ascar; Stelia, Valery; Reshetov, Alexander; Shymanskyi, Artem
    ENG: In 2015, in the territory of Kyiv (Ukraine) and in 2012-2017 in Transnistria (Moldova), two mixed colonies consisting of two species of ants – Lasius fuliginosus and L. umbratus were observed. Another 2 mixed colonies were discovered in 2021 in the territory of the city of Rivne (Ukraine). The aim of the study was to describe the observed mixed colonies, analyze the interaction of workers of two species on the trails, and by mathematical modelling to determine the probability of preserving queens of both species as part of a mixed colony. On the trails of the colonies from Kyiv and Rivne, the number of workers of L. fuliginosus is slightly higher than that of L. umbratus, so is the number of L. Fuliginosus workers in the colony. Workers of both species were making contact both within the same species and interspecific contacts, but trophobiosis with aphids has been recorded only by L. fuliginosus. The most likely of the 4 options considered was the survival of the queens of both species, otherwise the dynamics of the population over 6 years of development (total population of the mixed colony from Kyiv: 27 thousand workers of L. umbratus, 72 thousand workers - L. fuliginosus and two colonies with same population from Rivne) is difficult to explain. The possibility of such mixed colonies co-existing for at least a few years is debated.