Showing papers on "Lasius published in 2021"

Wheeler’s dilemma revisited: first Oecophylla–Lasius syninclusion and other ants syninclusions in the Bitterfeld amber (late Eocene)

Abstract: The first syninclusions of extant tropical and Holarctic ant genera are reported from Bitterfeld amber: the tropical Oecophylla F. Smith (O. brischkei Mayr, 1868) with the Holarctic genus Lasius F. (four workers of L. schiefferdeckeri Mayr, 1868), and others. The ratio of tropical and Holarctic ants in Bitterfeld, Baltic, Rovno and Danish ambers is analyzed; Holarctic ants dominate in all ambers, consistent with late Eocene climate. Oecophylla, Lasius and the temperate extant Palaearctic caddisfly genus Beraeodes Eaton are dominant as compression fossils in the terminal Eocene Bembridge Marls, UK. Syninclusions of Oecophylla with Lasius, as well as syninclusions of Beraeodes with Yantaromyrmex Dlussky et Dubovikoff, 2013 in Rovno amber, are consistent with an equable climate of the late Eocene amber forests of Europe. The cooccurrence of Oecophylla, Lasius and Beraeodes at the terminal Eocene in the Bembridge Marls supports a late Eocene age of European ambers. The coexistence of Oecophylla and Lasius in Europe was possible only from the late Eocene to the late Miocene: until the late Eocene, the climate in European middle latitudes was too hot for aphids, the obligate symbionts of Lasius, but after the late Miocene it became too cold for Oecophylla. The dominance of Oecophylla in the periodically flooded terminal Eocene Bembridge environment might be explained by its arboreal lifestyle providing a competitive advantage over terrestrial Formica species, for which nesting places were quite limited under these conditions. How to cite this article: Radchenko A.G., Perkovsky E.E. 2021. Wheeler’s dilemma revisited: first Oecophylla–Lasius syninclusion and other ants syninclusions in the Bitterfeld amber (late Eocene) // Invert. Zool. Vol.18. No.1. P.47–65. doi: 10.15298/invertzool.18.1.05

Hierarchical networks of food exchange in the black garden ant Lasius niger.

Abstract: In most eusocial insects, the division of labor results in relatively few individuals foraging for the entire colony. Thus, the survival of the colony depends on its efficiency in meeting the nutritional needs of all its members. Here, we characterize the network topology of a eusocial insect to understand the role and centrality of each caste in this network during the process of food dissemination. We constructed trophallaxis networks from 34 food-exchange experiments in black garden ants (Lasius niger). We tested the influence of brood and colony size on (i) global indices at the network level (i.e., efficiency, resilience, centralization, and modularity) and (ii) individual values (i.e., degree, strength, betweenness, and the clustering coefficient). Network resilience, the ratio between global efficiency and centralization, was stable with colony size but increased in the presence of broods, presumably in response to the nutritional needs of larvae. Individual metrics highlighted the major role of foragers in food dissemination. In addition, a hierarchical clustering analysis suggested that some domestics acted as intermediaries between foragers and other domestics. Networks appeared to be hierarchical rather than random or centralized exclusively around foragers. Finally, our results suggested that networks emerging from social insect interactions can improve group performance and thus colony fitness.

Searching for new predators of the invasive Halyomorpha halys: the role of the black garden ant Lasius niger

Abstract: In recent years, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae, Cappaeini) has become an invasive pest in North America and Europe, where it caused extensive damage to agriculture, resulting in great economic losses. Evaluating the potential of native predators in the invaded areas, ants might represent good candidates thanks to their biology, ecology, and behavior. In Italy, H. halys proved to be the top key pest in pear orchards, where the black garden ant, Lasius niger (L.) (Hymenoptera: Formicidae, Lasiini), is the most abundant ant species. The aim of this study was to evaluate the predatory ability of L. niger on the eggs and on all the juvenile instars of H. halys under laboratory conditions. The results indicate that L. niger significantly reduces the survival of the second and third nymphal instars by 56 and 58%, respectively, but it is unable to reduce the egg hatching and the survival of the first, fourth, and fifth instars. Our preliminary results obtained in laboratory conditions suggest a possible role of the ant L. niger in controlling H. halys invasion mainly acting on the smaller and more mobile nymphal stages. The effective role of this species as potential biocontrol agents of H. halys in fruit orchards in association with other ant species as well as with other predatory insects is discussed.

Aphids harbouring different endosymbionts exhibit differences in cuticular hydrocarbon profiles that can be recognized by ant mutualists.

Abstract: Cuticular hydrocarbons (CHCs) have important communicative functions for ants, which use CHC profiles to recognize mutualistic aphid partners. Aphid endosymbionts can influence the quality of their hosts as ant mutualists, via effects on honeydew composition, and might also affect CHC profiles, suggesting that ants could potentially use CHC cues to discriminate among aphid lines harbouring different endosymbionts. We explored how several strains of Hamiltonella defensa and Regiella insecticola influence the CHC profiles of host aphids (Aphis fabae) and the ability of aphid-tending ants (Lasius niger) to distinguish the profiles of aphids hosting different endosymbionts. We found significant compositional differences between the CHCs of aphids with different infections. Some endosymbionts changed the proportions of odd-chain linear alkanes, while others changed primarily methyl-branched compounds, which may be particularly important for communication. Behavioural assays, in which we trained ants to associate CHC profiles of endosymbiont infected or uninfected aphids with food rewards, revealed that ants readily learned to distinguish differences in aphid CHC profiles associated with variation in endosymbiont strains. While previous work has documented endosymbiont effects on aphid interactions with antagonists, the current findings support the hypothesis that endosymbionts also alter traits that influence communicative interactions with ant mutualists.

Phylogeny, evolution, and classification of the ant genus Lasius, the tribe Lasiini, and the subfamily Formicinae (Hymenoptera: Formicidae)

Abstract: Within the Formicidae, the higher classification of nearly all subfamilies has been recently revised due to the findings of molecular phylogenetics. Here, we integrate morphology and molecular data to holistically address the evolution and classification of the ant genus Lasius, its tribe Lasiini, and their subfamily Formicinae. We accomplish this through a critical re-examination of morphology of extant and fossil taxa, molecular phylogenetic analyses, total-evidence dating under fossilized birth-death process, phylogeography, and ancestral state estimation. We use these results to provide revised taxonomic definitions for the Lasiini and select genera, and we provide a key to the genera of the Lasiini with emphasis on the Lasius genus group. We find that the crown Lasiini originated around the end of the Cretaceous on the Eurasian continent and is divisible into four morphologically distinct clades: Cladomyrma, the Lasius genus group, the Prenolepis genus group, and a previously undetected lineage we name XXX gen. n. The crown of the Lasius genus group is considerably younger than that of the Prenolepis genus group, indicating that extinction has played a major role in the evolution of the former clade. Lasius itself is divided into two well-supported monophyletic groups which are approximately equally speciose. We present evidence that temporary social parasitism and fungiculture arose in Lasius two times independently. Additionally, we recover the paraphyly of three Lasius subgenera and propose replacing all subgenera with an informal species group classification: Lasius = Acanthomyops syn. rev., = Austrolasius syn. n., = Cautolasius syn. n., = Chthonolasius syn. n., = Dendrolasius syn. n. Total-evidence analysis reveals that the Baltic-region amber fossil species {dagger}Lasius pumilus and {dagger}Pseudolasius boreus are misplaced to genus; we therefore designate {dagger}XXX gen. n. for the former and {dagger}XXX gen. n. for the latter. Further, we transfer {dagger}XXX and {dagger}Glaphyromyrmex out of the tribe, considering the former to be incertae sedis in the subfamily, and the latter a member of the Formicini (tribal transfer). Two final taxonomic actions are deemed necessary: synonymy of Lasius escamole Reza, 1925 with Liometopum apiculatum Mayr, 1870 syn. n. (subfamilial transfer), and transfer of Paratrechina kohli to Anoplolepis (tribal transfer, forming A. kohli (Forel, 1916) n. comb.). Summary of taxonomic actionsO_LISubgenera of Lasius synonymized: Lasius = Acanthomyops syn. rev. = Austrolasius syn. n. = Cautolasius syn. n. = Chthonolasius syn. n. = Dendrolasius syn. n. C_LIO_LILasius myrmidon transferred to XXX gen. n. (Lasiini, XXX genus group). C_LIO_LI{dagger}Lasius pumilus transferred to {dagger}XXX gen. n. (Lasiini, XXX genus group). C_LIO_LI{dagger}Pseudolasius boreus transferred to {dagger}XXX gen. n. (incertae sedis in Formicinae) (tribal transfer). C_LIO_LI{dagger}Glaphyromyrmex transferred to the Formicini from the Lasiini (tribal transfer). C_LIO_LILasius escamole Reza, 1925 synonymized with Liometopum apiculatum Mayr, 1870, syn. n. (subfamilial transfer). C_LIO_LIParatrechina kohli (Forel, 1916) transferred to Anoplolepis (Plagiolepidini) (genus and tribal transfer). C_LI

Ant diversity on the largest Mediterranean islands: on the presence or absence of 28 species in Sicily (Hymenoptera, Formicidae)

Abstract: The ant fauna of Sicily, the largest island in the Mediterranean basin, has been significantly overlooked over the time. Drafting a reliable Sicilian ant checklist requires extensive field surveys, a careful review of the literature and of museum specimens, as well as the taxonomic investigation of some problematic issues. As a part of these ongoing efforts, we present our results on the presence or absence of 25 species. By analyzing specimens collected during the last 35 years across the island and reviewing old records in the light of present-day taxonomy, we provide evidence of the presence of 9 species (Camponotus ruber, Lasius myops, L. platythorax, Plagiolepis schmitzii, Ponera testacea, Solenopsis orbula, Temnothorax clypeatus, T. nylanderi, and T. ravouxi), while suggesting the absence of 19 others (Camponotus ligniperda, C. sicheli, C. spissinodis, Formica lugubris, Lasius alienus, L. flavus, L. niger, L. paralienus, Messor minor, M. wasmanni, Monomorium monomorium, Myrmica scabrinodis, M. spinosior, Nylanderia sp. 2 sensu Schifani and Alicata 2018, Solenopsis fugax, Temnothorax luteus, T. tuberum, Tetramorium caespitum, and T. indocile). Similar studies are necessary across Italy, as a significant portion of the existing ant records is outdated due to the evolved taxonomic framework.

Potent Ant Deterrents Emitted from Nematode-Infected Insect Cadavers.

Abstract: Most known species of entomopathogenic nematodes (EPNs) are generalist obligate parasites of insects. They kill their hosts within days after infection and mortality is mainly caused by toxins produced by bacteria that co-infect the hosts and serve as food for the nematodes. EPNs can infect a very broad spectrum of insects and these insects can therefore be expected to have evolved strategies to avoid infection. Indeed, ants are known to avoid feeding on EPN-infected insect cadavers, most likely because they are repelled by semiochemicals that emanate from the cadavers. The source and nature of these repellents are so far unknown. In a series of behavioral and chemical analytical experiments we identified hexadecanal and 2-heptadecanone as two compounds that are emitted by insect larva that are infected by the EPN Steinernema feltiae, but not by uninfected larvae. When spiking honey water with the two semiochemicals, they were confirmed to be highly deterrent to the ant Lasius niger. The environmentally benign hexadecanal and 2-heptadecanone could be employed to ward off ants and possibly other pests. Additional experiments are needed to fully determine their application potential.

Varying impact of neonicotinoid insecticide and acute bee paralysis virus across castes and colonies of black garden ants, Lasius niger (Hymenoptera: Formicidae).

Abstract: Pesticides and pathogens are known drivers of declines in global entomofauna. However, interactions between pesticides and viruses, which could range from antagonistic, over additive to synergistic, are poorly understood in ants. Here, we show that in ants the impact of single and combined pesticide and virus stressors can vary across castes and at the colony level. A fully-crossed laboratory assay was used to evaluate interactions between a sublethal dose of the neonicotinoid thiamethoxam and Acute bee paralysis virus (ABPV) in black garden ants, Lasius niger. After monitoring colonies over 64 weeks, body mass, neonicotinoid residues and virus titres of workers and queens, as well as worker behavioural activity were measured. ABPV, but not thiamethoxam, reduced activity of workers. Neonicotinoid exposure resulted in reduced body mass of workers, but not of queens. Further, thiamethoxam facilitated ABPV infections in queens, but not in workers. Overall, virus exposure did not compromise detoxification and body mass, but one colony showed high virus titres and worker mortality. Although the data suggest additive effects at the level of individuals and castes, co-exposure with both stressors elicited antagonistic effects on colony size. Our results create demand for long-term holistic risk assessment of individual stressors and their interactions to protect biodiversity.

Towards more intimacy: moderate elevation of temperature drives increases in foraging and mutualistic interactions between Lasius niger and Aphis fabae

Abstract: 1. Climate change will likely affect the association between species interacting at different trophic levels. However, studies focusing on the impact of an elevation of temperature on ant‐hemipteran mutualism remain scarce. 2. In the present study we investigated, in laboratory conditions, the foraging behaviour of the ant Lasius niger and its mutualistic interaction with the aphid Aphis fabae under three conditions of temperatures (i.e. 20°C, 23°C, and 26°C), as predicted by climatic scenarios. 3. Aphids were more mobile but as likely to release honeydew droplets at higher temperatures. As regards the ants, a moderate 3°C increase of temperature positively impacted their mutualistic interaction with aphids. Such reinforcement was achieved through an increase in the walking speed of ant foragers, in the number of mobilised ants as well as in the total amount of honeydew harvested by the colony. 4. A further elevation of temperature to 26°C reduced the benefits gained by the aphid‐tending ants, in terms of lower amount of collected honeydew. 5. Based on our results, we hypothesise that, in temperate regions, a moderate increase of ambient atmospheric temperature by 3°C will benefit to the L. niger ‐ A. fabae mutualistic interaction. A more marked elevation of 6°C may represent a threshold thermal value above which a switch of partners or a disruption of the interaction may occur under the temperatures predicted for the end of the century. These results demonstrate the fragility of mutualistic interactions, and more particularly their sensitivity to temperature increases predicted by realistic forecast models.

Study of Cellulose-Destroying Activity of Actinobacteria Associated with Ants

Abstract: Among actinobacteria associated with ants Camponotus vagus, Formica cunicularia, and Lasius niger, their nests, and intact soils, cellulolytic activity was screened in medium with carboxymethyl cellulose (CMC) using Congo Red dye. Assessment of culture fluids of tested strains on the CMC-plates and comparing them with solutions of the commercial cellulase preparation allowed for quantifying their activity. Data were confirmed by evaluating endo-1,4-glucanase activity using the 3,5-dinitrosalicylic acid (DNS) method. The three most active strains of actinobacteria were isolated from ants Camponotus vagus, Lasius niger, and Formica cunicularia and belonged to the genus Streptomyces. The 16S rDNA sequences of the strains Streptomyces sp. Fu2, Streptomyces sp. Ln9, and Streptomyces sp. Pe3 were deposited in the GenBank under accession numbers MN227506, MN227508, and MG 705182, respectively. Specific endoglucanase and β-glucosidase activity of these strains corresponded to that of cellulose- and lignin-destroying streptomycetes described in the literature.

Discoveries and fate of six ant (Hymenoptera, Formicidae) species on the Faroe Islands

Abstract: Ants have historically not been recorded on the Faroe Islands. We report ants on the Faroe Islands for the first time, with all detections assumed to be recent accidental arrivals with human commerce. We detail thirteen detections of six ant species. The black garden ant Lasius niger has been found seven times since 1996, five times as established colonies. The red wood ant Formica rufa, Camponotus fallax and two detections of black garden ant Lasius niger were discovered in low numbers (1–4 individuals), and independent of any source of origin. No colonies of these species were ever found and the incursions are presumed to have died naturally. Pharaoh ant Monomorium pharaonis was discovered on a seafaring vessel and once in a private home. The incursion in the private home was eradicated but it is unknown what action was taken on the ship. Ghost ant Tapinoma melanocephalum was discovered on a fishing vessel and eradicated. Tapinoma ibericum was found in a pack of purchased fruits. We anticipate that ant incursions to the Faroe Islands will increase with increasing human commerce, and that the ability for some species to establish viable colonies will also increase.

Complete mitochondrial genome of the jet ant Lasius spathepus Wheeler, W.M., 1910 (Formicidae; Hymenoptera)

Abstract: The genus Lasius is a conspicuous and popular genus of ants found in the Holarctic regions. We have completed the mitochondrial genome of Lasius spathepus as the first mitochondrial genome of Lasiu...

Local coexistence of native and invasive ant species is associated with micro-spatial shifts in foraging activity

Abstract: Invasive species often displace native species by outcompeting them. Yet, some native species can persist even in heavily invaded areas. The mechanisms mediating this local coexistence are still unclear. Fine-scale microclimatic heterogeneity could promote the local coexistence of native and invasive animal competitors. We tested if native ant species could coexist with a recent ant invader, Tapinoma magnum, by shifting their foraging activity in time or space to different microclimatic conditions. We compared the foraging activity of native epigeic ant species among invaded and uninvaded sites. We collected ants at baits in green spaces on the north, east, south and west sides of buildings in the morning, at noon and in the afternoon to test if native species foraged under different microclimatic conditions in invaded sites. Invaded sites had lower ant species richness, diversity, and relative abundance. The native black garden ant Lasius niger – one of the most widespread Palearctic ant species – persisted at high densities in invaded areas but foraged less on the east side of buildings and more on the west side. Microclimatic heterogeneity might promote native and invasive species coexistence by allowing some native species to shift their foraging behaviour to locally avoid or outcompete invasive competitors. Better understanding how fine-scale micro-environmental heterogeneity affects native species’ persistence in invaded areas could help to predict and locally mitigate the negative impacts of biological invasions.

No specialist pheromone‐ignoring ants in Lasius niger

Abstract: In insect societies, the balance between exploitation of known resources and exploration of new ones is important to ensure sufficient resources. Mass recruiting ants, such as Lasius niger, use pheromone trails to recruit nestmates to a newly discovered food source. Pheromone following, however, shows characteristic non‐following (lapse) rates among different species, with ∼20% of L. niger foragers ignoring pheromone. These characteristic lapse rates might simply be ‘noise’, or they might indicate a subset of specialised explorative foragers, a scouting caste, that consistently ignores pheromone in order to explore. Here we show pheromone ignoring is not a repeatable behaviour in L. niger foragers – ants who did not follow a trail were no more likely to ignore it again an hour later than ants which did follow it. Our findings suggest that there is no subset of specialised pheromone‐ignoring L. niger foragers. This may be due to their moderate colony size and strong reliance on individual memories: species with larger colony sizes or a weaker reliance on private information (i.e. memory) may have specialist non‐followers. Our work raises the question: what is a scout ant? We encourage future research to investigate the presence of a scouting caste in other ant species using our straightforward methodology, as a social information‐ignoring caste may be rarer than expected.

Interactions of ants with native and invasive lady beetles and the role of chemical cues in intraguild interference

Abstract: The predator-predator naivete hypothesis suggests that non-native predators benefit from being unknown to native predators, resulting in reduced intraguild interference with native predators This novelty advantage should depend on the ability of native predators to recognize cues of non-native predators Here, we compared ant aggression and lady beetle reaction in four native and the invasive lady beetle species Harmonia axyridis In addition, we tested whether lady beetle cuticular hydrocarbons (CHCs) are involved in species recognition, which might explain naivete if the invasive species has a specific CHC profile To this end, we conducted behavioral assays confronting two native ant species with both living lady beetles and lady beetle elytra bearing or lacking CHCs of different lady beetle species Finally, we characterized CHC profiles of the lady beetles using GC–MS In general, the aggression of Lasius niger was more frequent than that of Myrmica rubra and L niger aggression was more frequent towards most native lady beetle species compared to H axyridis The removal of CHCs from lady beetle elytra reduced aggression of both ant species If CHCs of respective lady beetle species were added on cue-free elytra, natural strength of L niger aggression could be restored CHC analyses revealed a distinct cue composition for each lady beetle species Our experiments demonstrate that the presence of chemical cues on the surface of lady beetles contribute to the strength of ant aggression against lady beetles Reduced aggression of L niger towards H axyridis and reduced avoidance behavior in H axyridis compared to the equally voracious C septempunctata might improve the invasive lady beetle’s access to ant-tended aphids

A taxonomic revision of the Palaearctic members of the Formica rufa group (Hymenoptera: Formicidae) – the famous mound-building red wood ants

Abstract: A revision of the Palaearctic members of the Formica rufa group, the famous mound-building red wood ants, is presented based on Numeric Morphology-Based Alpha-Taxonomy (NUMOBAT) and on genetic information from studies published in cooperation with others. Standardized morphological character systems were described numerically to allow objective hypothesis formation by exploratory data analyses and testing by hypothesis-driven data analyses. NUMOBAT data were recorded in a total of 1200 samples with 5500 worker individuals and 410 gynes. Comparative tables to workers and gynes of all species and the most frequent hybrids and a key to the workers are presented. Considering 54 available names, the survey recognized 13 good species, 32 junior synonyms and eight names not interpretable to species level (incertae sedis). The ratio of junior synonyms against the number of recognized species is elevenfold the ratio found in a revision of Palaearctic Lasius s.str. conducted by the same author in 2020 with basically the same methodology. Excessive name production in the F. rufa group is partly result of the big attention these eye-catching ants have received by naturalists but it also reflects the enormous difficulties to reasonably interpret a multitude of phenotypes. These difficulties are caused by extraordinary frequency of reticulate evolution, particular mechanisms for the evolution of deviating local populations, and intraspecific polymorphism with differences sometimes being larger than those between species. Hybridization and introgression were shown or made plausible in 46% of the 13 recognized species with regional hybridization frequencies of above 20% in three species. The author assumes that the evolutionary history of F. rufa group ants will turn out as extremely reticulate comparable with the situation in Heliconius butterflies or Darwin Finches once whole genome analyses will be available for all species. The 13 species of the F. rufa group were assigned to four species complexes: (a) the F. rufa complex with F. rufa Linnaeus, 1761 and F. polyctena Foerster, 1850; (b) the F. lugubris complex with F. lugubris Zetterstedt, 1838, F. helvetica sp.n., F. paralugubris Seifert, 1996, F. aquilonia Yarrow, 1955 and F. ussuriensis sp.n.; (c) the F. pratensis complex with F. pratensis Retzius, 1783 and F. kupyanskayae Bolton, 1995 and (d) the F. truncorum complex with F. truncorum Fabricius, 1804, F. dusmeti Emery, 1909, F. frontalis Santschi, 1919 and F. sinensis Wheeler, 1913. Formica yessensis Wheeler, 1913 is recognized as a new junior synonym of F. truncorum. Special sections describe the situation in six hybrid combinations. Comments on species incertae sedis and unavailable names are given in a final chapter.Open access, licensed under CC BY 4.0. © 2021 The Author(s).DOI: 10.25849/myrmecol.news_031:133Pages: 133-179Volume: 31Year: 2021Journal: Myrmecol. News

Does breeding habitat affect the amount of ants in the diet of European bee-eater nestlings?

Abstract: European bee-eater (Merops apiaster Linnaeus, 1758; Coraciiformes: Meropidae) is known as a bee-predator, but its food spectrum is variable and depends on the current supply. This is the first study focused on the ants (Hymenoptera: Formicidae) as important prey in the diet of the European bee-eater. In 2017, 9,604 insect prey was obtained from pellets gained from two colonies breeding: (1) underground of a grazed sand dune (Radvaň nad Dunajom) and (2) in the sandy wall (Gabcikovo) without pasture, both in southern Slovakia. Five ant taxa were identified, the list of ants in the bee-eater’s diet was expanded by three taxa Lasius sp., Camponotus vagus (Scopoli, 1763) and Liometopum microcephalum (Panzer, 1798). In summary, ants represent the second most abundant family (12.35 %) of total prey. Compared to adults, nestlings (15.04 %) ate significantly more ants than adults (10.97 %). To study the ants’ composition in the diet of bee-eater near to different types of habitats, the pellets of nestlings were chosen because they more accurately reflect the sources of insect during the breeding season. Differences in the feeding of the European bee-eater nestlings between the grazed and the non-grazed locality were confirmed, where Lasius sp. and Tetramorium sp. highly correlated with grazing site. Moreover, nestlings ate significantly more ants in the area, where an open habitat was managed by grazing (6.55 vs. 15.04 %). The presented research indicates the importance of traditional pastures in the country for ants and also for bee-eaters. These ecosystem engineers are likely to find more microhabitats on the pastures, which has also been reflected in the diet of the nestlings breeding on the grazed site.

The Myrmecofauna (Hymenoptera: Formicidae) of Hungary: Survey of Ant Species with an Annotated Synonymic Inventory

Abstract: Ants (Hymenoptera: Forimicidae) are exceedingly common in nature. They constitute a conspicuous part of the terrestrial animal biomass and are also considered common ecosystem engineers. Due to their key role in natural habitats, they are at the basis of any nature conservation policy. Thus, the first step in developing adequate conservation and management policies is to build a precise faunistic inventory. More than 16,000 valid ant species are registered worldwide, of which 126 are known to occur in Hungary. Thanks to the last decade's efforts in the Hungarian myrmecological research, and because of the constantly changing taxonomy of several problematic ant genera, a new checklist of the Hungarian ants is presented here. The state of the Hungarian myrmecofauna is also discussed in the context of other European countries' ant fauna. Six species (Formica lemani, Lasius nitidigaster, Tetramorium immigrans, T. staerckei, T. indocile and Temnothorax turcicus) have been reported for the first time in the Hungarian literature, nine taxon names were changed after systematic replacements, nomenclatorial act, or as a result of splitting formerly considered continuous populations into more taxa. Two species formerly believed to occur in Hungary are now excluded from the updated list. All names are nomenclaturally assessed, and complete synonymies applied in the Hungarian literature for a certain taxon are provided. Wherever it is not self-evident, comments are added, especially to explain replacements of taxon names. Finally, we present a brief descriptive comparison of the Hungarian myrmecofauna with the ant fauna of the surrounding countries. The current dataset is a result of ongoing work on inventorying the Hungarian ant fauna, therefore it is expected to change over time and will be updated once the ongoing taxonomic projects are completed.

Differing Dietary Nutrients and Diet-Associated Bacteria Has Limited Impact on Spider Gut Microbiota Composition.

Abstract: Spiders are a key predator of insects across ecosystems and possess great potential as pest control agents. Unfortunately, it is difficult to artificially cultivate multiple generations of most spider species. Since gut bacterial flora has been shown to significantly alter nutrient availability, it is plausible that the spiders’ microbial community plays a key role in their unsuccessful breeding. However, both the gut microbial composition and its influencing factors in many spiders remain a mystery. In this study, the gut microbiota of Campanicola campanulata, specialists who prey on ants and are widely distributed across China, was characterized. After, the impact of diet and diet-associated bacteria on gut bacterial composition was evaluated. First, two species of prey ants (Lasius niger and Tetramorium caespitum) were collected from different locations and fed to C. campanulata. For each diet, we then profiled the nutritional content of the ants, as well as the bacterial communities of both the ants and spiders. Results showed that the protein and carbohydrate content varied between the two prey ant species. We isolated 682 genera from 356 families in the ants (dominant genera including Pseudomonas, Acinetobacter, Paraburkholderia, Staphylococcus, and Novosphingobium), and 456 genera from 258 families in the spiders (dominated by Pseudomonas). However, no significant differences were found in the gut microbiota of spiders that were fed the differing ants. Together, these results indicate that nutritional variation and diet-associated bacterial differences have a limited impact on the microbial composition of spider guts, highlighting that spiders may have a potentially stable internal environment and lay the foundation for future investigations into gut microbiota.

Geographic and Intraspecific Variation of Cold Hardiness in Ants of the Genus Lasius Fabricius, 1804 (Hymenoptera, Formicidae)

Abstract: As a model species to study the geographic variation of cold hardiness in insects, we use ants Lasius flavus from populations of territories separated by thousands of kilometers (southern Finland, the Moscow region, and Amur oblast) and with contrasting climates, from maritime variants to climates differing in degrees of continentality. We measure supercooling points (SCPs) and the temperature at which 50% of the sample perishes (LT50%) and evaluate overwintering conditions. The data on L. flavus are compared to similar data obtained on L. niger, аs well as to similar measurements in separate nests of L. alienus, L. psammophilus, and L. fuliginosus, which were published earlier. The workers of L. flavus and L. niger have similar values of cold hardiness (LT50% from –13 to –15°C, minimum average SCP from –24 to –25°C), although these species inhabit different climatic zones and arrange their overwintering chambers at different depths. Such resistance to long-term exposure to negative temperatures is more than sufficient for overwintering, even in the coldest of the studied areas (village of Arkhara, Amur oblast), where the average minimum temperature in January in the ant overwintering chambers at a depth of 50 cm does not fall below –6°C. The variation in cold hardiness and higher values of its parameters in other studied ant species are due to their insufficient preparedness for overwintering. However, the narrow range of SCP values (from –27 to –29°C) in the most cold-resistant individuals of all studied species strongly suggests that their average SCP and LT50% values are similar to those of L. flavus and L. niger. The similar (or perhaps identical) cold hardiness of the studied ant species appears to be a stable trait of the genus Lasius, as was demonstrated for another ant genus, Myrmica, and which is dissimilar to the genus Formica, in which different species have individual characteristics of cold-resistance. Excessive for overwintering in the warmer climate (southern Finland and Estonia), such cold hardiness appears to have no adaptive value. It can be considered a byproduct of diapause, which is manifested in preadaptation to withstand negative temperature. However, it was this cold hardiness that allowed the ant species to colonize the vast territory of southern Siberia and the Far East.

Myrmecofauna (Hymenoptera, Formicidae) of the yew-boxwood grove (Western Caucasus, Russia)

Abstract: The data on the fauna and biotopic distribution of ants (Hymenoptera, Formicidae) in the yew-boxwood grove of the Caucasian State Natural Biosphere Reserve are presented. A total of 27 ant species were identified, belonging to 17 genera of 4 subfamilies (Dolichoderinae , Ponerinae , Formicinae , and Myrmicinae ). The genera – Lasius F. and Temnothorax Mayr are the richest and include 5 species each. For the yew-boxwood grove, all species of ants are presented for the first time.