Zoodiversity

Potential for Transition to a Polygynous-Supercolonial Demography in Lasius niger (Hymenoptera, Formicidae)

S. Stukalyuk — Mon, 14 Apr 2025 09:18:02 +0000

The formicine ant, Lasius niger (Linnaeus, 1758), is one of the most abundant and intensively studied Palaearctic ant species, and was previously thought to form exclusively monogynous colonies, spread by single-queen dispersal, and occur claustrally. Two closely neighboring nest complexes of L. niger were observed in 2017–2020 in an abandoned field near Kyiv / Ukraine. Nest complex A contained 14650 nest mounds on an area of 11.8 ha and nest complex B contained 15600 mounds on an area of 13.3 ha. Data were collected by measuring the height and diameter of nest mounds and counting the number of workers in each nest. In addition, worker movements between nests were observed and tests for aggressive behaviour between ants from different nests and sub-complexes were carried out. In the pleometrosis experiments, young mated gynes collected from the territory of nest complex B showed mutual tolerance after the first workers emerged from pupae. In contrast, in pleometroses with gynes from a distant monodomous population, the gynes began a deadly fight after workers emerged, with only a single queen surviving. Nest mounds within nest complexes are connected by a well-developed network of trails. The results of the analysis showed a positive correlation between nest size and population size. The coefficient of determination r2 for nest mound volume was 0.68415, indicating that 68.4 % of the variation in population size was explained by changes in nest mound volume. In comparison, r2 for nest mound diameter was 0.7872, meaning that 78.7 % of the variation in population size was explained by changes in nest mound diameter, while r2 for nest mound height was 0.42734, meaning that only 42.7 % of the variation in population size was explained by changes in nest mound height. Observations of worker movements revealed a high degree of organisation and specialisation, helping to maintain connections between nest mounds. Aggression tests revealed low levels of aggression between workers from different zones of the same nest complex, but increased aggression in confrontations between workers from a nest complex with workers from a remote monodomous population and with workers from a second nest complex. Pleometrosis and reduced aggression between workers facilitate the integrity of the nest complex and its rapid growth. Based on the data obtained, it was concluded that the low aggressiveness of L. niger ants allows them to coexist over large areas in the form of large nest complexes containing thousands and tens of thousands of nest mounds. Additional auxiliary nests were identified that may become new full-scale nest mounds in the future, indicating a potentially higher settlement density than if only nest mounds were considered.

Alpiscorpius victori sp. n. from the Murat Mountain, Kütahya and Uşak Provinces, Turkey (Scorpiones: Euscorpiidae)

E. A. Yağmur — Fri, 11 Apr 2025 11:29:54 +0000

A new scorpion species, Alpiscorpius victori sp. n., is described from Mount Murat, located in Kütahya and Uşak Provinces in the Aegean Region of western Turkey, based on morphological evidence. The species is classified within the genus Alpiscorpius Gantenbein et al., 1999, due to the presence of three trichobothria in the em series on the external surface of the pedipalp patella. With the addition of this species, the number of known species in the family Euscorpiidae rises to 24, while the genus Alpiscorpius now includes six species in Turkey.

First Record of Bradoponera wunderlichi (Hymenoptera, Formicidae) from Rovno Amber, with Description of the Worker Caste

A. G. Radchenko, M. R. Khomych, M. M. Kalmer — Tue, 04 Mar 2025 12:11:53 +0000

Previously unknown workers of Bradoponera wunderlichi Baroni Urbani & De Andrade, 2003 are described, and this extinct species is recorded for the first time in Rovno amber. We show that the lectotype of Bradoponera meieri Mayr, 1868 was previously designated by Dlussky (2009) based on a wrong collection number, which is corrected here.

Population Characteristics of Molluscs of the Family Sphaeriidae (Mollusca, Bivalvia) of Reservoirs and Watercourses in the Northern Right-Bank Polissia of Ukraine (Pripyat Sub-Basin)

L. M. Shevchuk, L. V. Bylyna — Tue, 18 Feb 2025 10:54:56 +0000

A total of 18 species of molluscs of the family Sphaeriidae (Mollusca, Bivalvia) were found in the water bodies of the northern right-bank Polissia of Ukraine (Pripyat sub-basin). Sphaerium solidum is indicated for the Pripyat sub-basin for the first time. The largest number of species (12) was found in the Horyn River, nine in the Pripyat River, six in the Uzh and Sluch Rivers, three in the Khomora River, two in the Ubort River and no species in the Turiya River. A total of 12 species were found in small rivers and six species in streams. Sphaeriidae molluscs were not found at all in out-of-channel ponds. In one collection point, from one to eight species were recorded at the same time. S. solidum, S. nucleus, and S. rivicola had the highest rates of occurrence in the study region (up to 15 %), for the rest of the species this rate was 1–10 %. The total incidence of Sphaeriidae was 44 %. The highest density of S. nucleus was recorded in the Uzh (29 specimens/m2), in most of the sampling sites the value did not exceed 10, mostly 1–3 specimens/m2. The lists of species (according to Sørensen's index) were most similar for the rivers Styr and Horyn (59 %), Pripyat and Horyn (57 %), Styr and Uzh (55 %), Ubort and Uzh (50 %). Changing conditions in anthropogenically modified water landscapes are probably the main reason for the disappearance of representatives of the family, which is why it is necessary to analyse the ecological characteristics of Sphaeriidae habitats.

Status and Distribution of Paraguayan Mammalia: Hystricomorpha 1. Erethizontidae and Chinchillidae

P. Smith — Tue, 18 Feb 2025 10:34:35 +0000

Two species of Erethizontidae and one species of Chinchillidae have been recorded in Paraguay. To date no specialized studies have been performed on them and their distribution is poorly known. This study clarifies the available data on the distribution, habitat affinities and nomenclature of the Paraguayan members of these families, and provides a complete Paraguayan bibliography of the species. Coendou spinosus is associated with the Atlantic Forest ecoregion and forests influenced by it, exclusively in eastern Paraguay. Coendou longicaudatus shows a near parapatric distribution with it, replacing that species in the gallery forests of the Cerrado and Humid Chaco ecoregions. Lagostomus maximus is confined to a small area of Dry Chaco along the northern Pilcomayo River in Boquerón department. The distributions of the two species of Paraguayan porcupines with respect to each other requires more data, and citizen science projects can contribute to clarification of the issues.