Formica Rufa Research Articles

Formica rufa ants have a limited effect on the abundance of the parasitic fly Ernestia rudis in Scots pine plantations

Red wood ants (the Formica rufa group) are important predators which affect animal communities in their territory. Therefore, they are useful in forest protection. On the other hand, they also prey on beneficial organisms. We have asked whether Formica rufa L. affects the abundance of the parasitic flies Ernestia rudis (Fallén). Ten anthills situated in about 40-year- old pine plantations were used for the study. The presence of E. rudis cocoons was assessed in eight soil samples excavated in the surrounding of each nest at a distance of 2–17 m. Our results show a considerably lower abundance of E. rudis only to 4.5 m from the nests. The occurrence of Formica rufa ants therefore had no significant effect on the beneficial E. rudis population in plantation forests, where ants populations are low.

Effect of Wood Ants (Formica rufa group) on Community Structure of Microarthropod

Kuzey yarım kürede yaygın olarak bulunan orman karıncaları (Formica rufa grubu) ibre, dal, ağaç kabuğu, reçine ve otsu türler kullanarak toprak üzerinde tepecik halinde yuva yaparlar. Yuva yapımında kullanılan organik madde, yuva etrafındaki toprakların özelliklerini değiştirir. Ayrıca orman karıncaları yiyecek arama faaliyetleriyle de yuva etrafındaki toprakların özelliklerini ve diğer canlıları etkilerler. Orman karıncalarının, mikroeklembacaklılar üzerindeki etkisini belirlemek için yürütülen bu çalışma, Çankırı Karatekin Üniversitesi Araştırma Ormanında gerçekleştirilmiştir. Karaçam (Pinus nigra) ormanında seçilen dört adet benzer hacimdeki (0,54±0,05 m3) kırmızı orman karıncası yuvasının yanından (0,5 m) ve 10 m uzağından çelik silindirler ile mikroeklembacaklılar örneklenmiştir. Teşhisleri ve sayımları yapılan mikroeklembacaklıların komünite yapıları ve çeşitlilik indeks değerlerine tekrarlı ölçümlerde varyans analizi ile uygulanarak değerlendirilmiştir. Sonuç olarak mikroeklembacaklıların miktarı ile farklı beslenme seviyelerindeki (çürükçül, yırtıcı ve otçul) canlıların miktarları yuvadan uzaklaştıkça artmıştır. Bununla birlikte karınca yuvalarının mikroeklembacaklı çeşitliliğini düşürdüğü belirlenmiştir.

Animate Orientation Based on Visual Landmarks and Scene Recognition

A biologically-inspired approach to robot route following is presented. The ant of the genus Formica rufa (a red forest ant) is used as a model species. These ants actively use collective foraging, unlike many other ant species. The scout ant remembers the route to food and can transmit information about the food location to foraging ants. Foragers can independently reach this place using this data and return home. The basis of the proposed method is the memorization the way by visual landmarks and fuzzy control. The animate path description model consists of a sequence of scenes and includes compass to account for the direction. The behavior of the animate-scout is implemented using an algorithm that simulates the foraging behavior of ants. The animate-forager performs actions to reproduce the route, applying the developed set of rules. The forager behavior is based on the same principles as that of a scout. But the scout remembers the scenes, and the forager recognizes and compares the visible scene and the scene from the route description. The actions of animates are presented in the form of elementary behavioral procedures. Each behavioral procedure is implemented using a finite state machine. The experiments for solving the foraging problem were carried out using a modeling system based on the ROS framework. The simulation results confirm the effectiveness of the proposed method. The method does not require large computing power and advanced sensory capabilities from the robot. It can also be used in reconnaissance and patrol tasks.

Wood ants as biological control of the forest pest beetles Ips spp.

Climate change is one of the major threats to biodiversity, but its impact varies among the species. Bark beetles (Ips spp.), as well as other wood-boring pests of European forests, show escalating numbers in response to the changes driven by climate change and seriously affect the survival of the forests through the massive killing of trees. Many methods were developed to control these wood-boring beetles, however, their implementation can be detrimental for other forest specialists. Ants are widely used for biological pest-control, so in our study, we aimed to test the effect of Formica polyctena on the control of the wood-boring beetles. The results show that the proportion of infested trees is significantly reduced by the increase of the number of F. polyctena nests, with a strong effect on those infested by Ips species. We also show that the boring beetle community is shaped by different biotic and abiotic factors, including the presence of F. polyctena nests. However, the boring beetle infestation was not related to the latitude, altitude and age of the forests. Based on our results, we assert the effectiveness of the red wood ants as biological pest control and the importance of their conservation to keep the health of the forests.

Red wood ants in Bulgaria: distribution and density related to habitat characteristics

The only National Inventory of red wood ants in Bulgaria was carried out about 50 years ago (1970–1973). Formica rufa Linnaeus, 1761, F. pratensis Retzius, 1783, F. lugubris Zetterstedt, 1838 and F. polyctena (as F. polyctena x rufa hybrid) were found in a current monitoring programme. This study presents data on their current distribution and nest density, and provides more details about the habitat requirements for conservation purposes. Field studies were carried out by the transect method along the main mountainous areas in Bulgaria. We found 256 nests of red wood ants along 172 transects. The most abundant species was F. lugubris, followed by F. rufa and F. pratensis. Among the environmental variables, the elevation, exposure, ecological groups of plants, stone cover, grass cover, canopy cover and forest age appeared as significantly related to the presence and nest density of red wood ants.

Comparative analysis of a geometric and an adhesive righting strategy against toppling in inclined hexapedal locomotion.

Animals are known to exhibit different walking behaviors in hilly habitats. For instance, cats, rats, squirrels, tree frogs, desert iguana, stick insects and desert ants were observed to lower their body height when traversing slopes, whereas mound-dwelling iguanas and wood ants tend to maintain constant walking kinematics regardless of the slope. This paper aims to understand and classify these distinct behaviors into two different strategies against toppling for climbing animals by looking into two factors: (i) the torque of the center of gravity (CoG) with respect to the critical tipping axis, and (ii) the torque of the legs, which has the potential to counterbalance the CoG torque. Our comparative locomotion analysis on level locomotion and inclined locomotion exhibited that primarily only one of the proposed two strategies was chosen for each of our sample species, despite the fact that a combined strategy could have reduced the animal's risk of toppling over even more. We found that Cataglyphis desert ants (species Cataglyphis fortis) maintained their upright posture primarily through the adjustment of their CoG torque (geometric strategy), and Formica wood ants (species Formica rufa), controlled their posture primarily by exerting leg torques (adhesive strategy). We further provide hints that the geometric strategy employed by Cataglyphis could increase the risk of slipping on slopes as the leg-impulse substrate angle of Cataglyphis hindlegs was lower than that of Formica hindlegs. In contrast, the adhesion strategy employed by Formica front legs not only decreased the risk of toppling but also explained the steeper leg-impulse substrate angle of Formica hindlegs which should relate to more bending of the tarsal structures and therefore to more microscopic contact points, potentially reducing the risk of hindleg slipping.

BIODIVERSITY OF EDAPHIC FAUNA IN GRAY FOREST SOILS OF THE REPUBLIC OF MOLDOVA

Gray forest soils of the natural ecosystems in the central and northern zones of the Republic of Moldova are the habitat and the source of conservation and reproduction of the edaphic fauna. They represent themselves the standards of the biodiversity for soil invertebrates. Invertebrates sampling was carried out from test cuts by manual sampling of soil layers to the depth of soil fauna occurrence. The main content of invertebrates in gray soils under the forest was in the layer of 0-20 cm. In addition to the Lumbricidae family there were found the species of the Clubionidae, Hydromiidae, Scarabaeidae, Oniscidae, Tortricidae, Julidae, Curculionidae, Carabidae, Geophilidae, Tenebrionidae, Melandryidae and Formicidae families. Species of Eisenia rosea, Euomphalia strigella, Formica rufa, Tortrix viridana, Curculio glandium, Melolontha melolontha and others have been identified in three subtypes of gray forest soils of natural ecosystems. The long use of these soils in agricultural production led to the considerable decrease in the number and biomass of invertebrates and degradation of the faunal complex in general. The number of families decreased from 6-12 to 1-3. Species of Lumbricidae, Elateridae, Tortricidae and Coccinellidae have been found in arable gray forest soils. The trophic pyramids are stable in the typical virgin gray soil. The relationship between trophic levels of the edaphic fauna in the typical gray forest soil is stronger in comparison with albic and molic gray forest soils.

Background substrate and nest semiochemicals mediate ant aggression towards a parasitic beetle

1. Background cues may affect the perception and processing of sensory stimuli used by species to detect other organisms. These additional environmental cues change the effectiveness of behavioural responses and eventually influence species interactions. Ants make use of an advanced sensing system to detect intruders, but little is known how cues of the heterogeneous soil substrate influence their behavioural response.2. Here, the aggressive response of red wood ants towards the beetle Notothecta flavipes, a parasitic nest associate, was tested against a background of two types of nest material present in the heterogeneous nests of wood ants, organic thatch (upper part of the nest) and sand (lower part of the nest). I used plaster as control. In addition, the three types of substrate were conditioned with or without chemical nest recognition cues of the host ant.3. Ant aggression was strongly affected by the type of background substrate. Compared to a control background of plaster, the likelihood of ant aggression was 2.8 times and 1.7 times lower against a background of organic thatch and sand, respectively. As visual cues were eliminated in the aggression tests, the reduced aggression levels may be caused by the interference of olfactory scents emitted by the substrate. By contrast, an increase of biting attempts was recorded when the background substrate was conditioned with chemical cues of the ants, suggesting that ants defend familiar smelling terrain more fiercely.4. Overall, these results suggest that the soil background may have complex and spatially variable effects on species interactions in heterogeneous patches.

Terpenes and fungal biomass in the nest mounds of Formica aquilonia wood ants

Nest mounds of wood ants of the Formica rufa group are built using conifer needles, small branches, other plant materials and soil. Conifer needles contain several mono and sesquiterpenes. Thus, wood ant nests may act as terpene hotspots in conifer forest soils. Some of the terpenes show antifungal activity and may thus cause small-scale heterogeneity in fungal biomass. We compared terpene concentrations and fungal biomass (ergosterol concentration) of nest material of the wood ant Formica aquilonia from the top, core and basement of 14 nest mounds in eastern Finland. Overall, α-pinene, camphene, sabinene, β-pinene, myrcene, limonene, camphor and longifolene were detected the most and were commonly present in all the studied layers. We found that terpene concentrations differed between the sampled nest material layers, being generally highest in the core of the nest and lowest at the basement of the nest. There was no association between the terpene concentration and material moisture. Fungal biomass was highest in the top layer, intermediate in core and lowest in basement; however, it was not negatively associated with terpene concentrations. Fungal biomass in nest mounds was positively associated with moisture and alkalinity. Nest mounds of Formica rufa group wood ants are complex structures with different chemical and microbial properties among its layers.

Moving apart together: co-movement of a symbiont community and their ant host, and its importance for community assembly

BackgroundSpecies interactions may affect spatial dynamics when the movement of one species is determined by the presence of another one. The most direct species-dependence of dispersal is vectored, usually cross-kingdom, movement of immobile parasites, diseases or seeds by mobile animals. Joint movements of species should, however, not be vectored by definition, as even mobile species are predicted to move together when they are tightly connected in symbiont communities.MethodsWe studied concerted movements in a diverse and heterogeneous community of arthropods (myrmecophiles) associated with red wood ants. We questioned whether joint-movement strategies eventually determine and speed-up community succession.ResultsWe recorded an astonishingly high number of obligate myrmecophiles outside red wood ant nests. They preferentially co-moved with the host ants as the highest densities were found in locations with the highest density of foraging red wood ants, such as along the network of ant trails. These observations suggest that myrmecophiles resort to the host to move away from the nest, and this to a much higher extent than hitherto anticipated. Interestingly, functional groups of symbionts displayed different dispersal kernels, with predatory myrmecophiles moving more frequently and further from the nest than detritivorous myrmecophiles. We discovered that myrmecophile diversity was lower in newly founded nests than in mature red wood ant nests. Most myrmecophiles, however, were able to colonize new nests fast suggesting that the heterogeneity in mobility does not affect community assembly.ConclusionsWe show that co-movement is not restricted to tight parasitic, or cross-kingdom interactions. Movement in social insect symbiont communities may be heterogeneous and functional group-dependent, but clearly affected by host movement. Ultimately, this co-movement leads to directional movement and allows a fast colonisation of new patches, but not in a predictable way. This study highlights the importance of spatial dynamics of local and regional networks in symbiont metacommunities, of which those of symbionts of social insects are prime examples.

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

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

Ant Diversity and Community Composition in Alpine Tree Line Ecotones

Simple SummaryAlpine grasslands are among the few terrestrial habitats not obviously dominated by ants. Yet few studies have addressed how ant communities change along tree-line ecotones on mountains. We combined five survey methods to assess ant assemblages along the tree line at five mountains in the south-central Alps of Italy. Ant species richness peaked directly at the tree line, but this was not due to a mixing of forest with grassland species. In subalpine forest and at the tree line, ant assemblages were dominated by mound-building red wood ants. Community composition and functional species traits indicated competition as a potential effect of community assembly in subalpine forest. Further, habitat features such as elevation, dwarf shrub cover, and the extent of a soil humus layer shaped species composition of ant communities around the tree line.Ants are crucial for the functioning of many terrestrial ecosystems, but detailed knowledge of their ecological role is often lacking. This is true for high mountains where a steep environmental gradient exists from mountainous forest, densely populated by ants, to grassland habitats above the tree line, harboring a sparse ant community. We assessed ant communities in and around the tree line ecotone on five slopes in the southern-central Alps, focusing on their species diversity, community composition, and functional dimensions. Species richness and functional diversity were highest directly at the ecotone. Ant community composition was shaped by elevation and shrub cover. Further, the abundance of the dominant mound-building red wood ants (Formica s. str.) influenced the community composition of the subordinate species. We conclude that over the tree line ecotone a shift in predominance from biotic limitations in the forest to abiotic filters in the alpine environment takes place.

Unexpected distribution of subordinates around nests of the wood ants

The hierarchical organization of multi-species ant communities can be determined by the colony size and worker density-dependent differences in behaviour, recruitment efficiency, and aggressiveness between colonies of different species. In this study, we compared the competitive effects of two territorial wood ant species, Formica rufa and F. polyctena, on the ant species subordinated to them (encounterers and submissives) that nest close-by their mounds. The nests of subordinates were mapped in 10 m2 plots around the mounds of each of the two wood ant species, situated at a distance of 10, 20 and 30 m in four directions. The most abundant subordinate species were two Myrmica species: M. rubra and M. ruginodis. Interestingly, the nests of subordinates had an even diversity, density and distribution along with the distance from the wood ant mounds. The wood ant presence had a species-specific negative effect on some of the subordinate species, which can be in relation with the smaller mound sizes in F. rufa compared to F. polyctena. Based on our results it seems that subordinate species, due to their adaptability, might tolerate the circumstances close-by the wood ant mounds by changes in their strategies, foraging behaviour, and switching to the use of alternative food sources, like corpses of wood ants present in high abundance. Although these might not allow reaching normal colony size and reproduction, they may allow the colonies to survive while maintaining relatively large nest densities.

Ecological Monitoring with Spy Satellite Images—The Case of Red Wood Ants in Romania

Dynamics of habitat conditions drive important changes in distribution and abundance of animal species making monitoring an important but also a challenging task when data from the past are scarce. We compared the distribution of ant mounds in the 1960s with recent inventories (2018), looking at changes in canopy cover over time, in a managed forest. Both historical and recent sources of information were used. Habitat suitability at present was determined using a Normalized Difference Vegetation Index (NDVI) image as a proxy for stand canopy cover. The NDVI product was obtained using Google Earth Engine and Sentinel 2 repository. For past conditions (no spectral information available), presence of edges and more open canopies was assessed on a Corona spy-satellite image and based on information from old forest management plans. A threshold distance of 30 m was used to assess location of ant nests compared to favorable habitats. Both old and new information sources showed that ants prefer intermediate canopy cover conditions in their vicinity. Nests remained clustered because of the heterogeneous habitat conditions, but spatial distribution has changed due to canopy alteration along time. The analysis on the NDVI was effective for 82% of cases (i.e., nests occurred within 30 m from favorable habitats). For all the remaining nests (18%), the Google Earth high resolution satellite image revealed in their vicinity the presence of small canopy gaps (undetected by the NDVI). These results show that historical satellite images are very useful for explaining the long-term dynamics of ant colonies. In addition, the use of modern remote sensing techniques provides a reliable and expedite method in determining the presence of favorable small-scale habitat, offering a very useful tool for ecological monitoring across large landscapes and in very different areas, especially in the context of ecosystem dynamics driven and exacerbated by climate change.

The distribution of a group of keystone species is not associated with anthropogenic habitat disturbance

AbstractAimRed wood ants (Formica rufa group) mitigate invertebrate pest outbreaks, alter invertebrate communities, and contribute to nutrient cycling. The IUCN lists these insects as near threatened. We investigated whether disturbances of Red Wood Ant (RWA) forest habitats related to recreation, infrastructure, and forest management were associated with RWA occurrence. We also investigated the habitat associations of this group.LocationSwitzerland.MethodsWe trained random forest models to predict RWA occurrence using data from 6,341 plots distributed throughout Swiss forests. Our explanatory variables included descriptions of vegetation, terrain, climate and human disturbance of the forest. A model trained using all of these variables (Model 1) was compared to another trained using all of these variables except those describing human disturbance (Model 2). We compared the abilities of these models to differentiate between RWA presences and absences using areas under receiver operator curves (AUC). The nature of the associations between the probability of RWA occurrence predicted by Model 1 and the explanatory variables that made the greatest contributions to the AUC of this model were investigated using individual conditional expectation plots.ResultsNo significant difference in AUC was detected between Models 1 and 2. RWA occurrence was positively associated with elevation, conifers, canopy gaps, ground cover vegetation and solar insolation while negatively associated with air temperature and a soil wetness index.Main conclusionsThe distribution of RWA within Swiss forests appeared unassociated with the human disturbances we investigated. To conserve RWA in Switzerland, we recommend the conservation of forests with high proportions of conifers, particularly those at high elevations. We also recommend forest management that promotes ground cover vegetation and open canopy structures. The negative associations between RWA occurrence and temperatures raise concerns for the prospects of RWA in the context of predicted climate warming.

A motion compensation treadmill for untethered wood ants (Formica rufa): evidence for transfer of orientation memories from free-walking training.

ABSTRACTThe natural scale of insect navigation during foraging makes it challenging to study under controlled conditions. Virtual reality and trackball setups have offered experimental control over visual environments while studying tethered insects, but potential limitations and confounds introduced by tethering motivates the development of alternative untethered solutions. In this paper, we validate the use of a motion compensator (or ‘treadmill’) to study visually driven behaviour of freely moving wood ants (Formica rufa). We show how this setup allows naturalistic walking behaviour and preserves foraging motivation over long time frames. Furthermore, we show that ants are able to transfer associative and navigational memories from classical maze and arena contexts to our treadmill. Thus, we demonstrate the possibility to study navigational behaviour over ecologically relevant durations (and virtual distances) in precisely controlled environments, bridging the gap between natural and highly controlled laboratory experiments.

P.186 Molecular pathways underlying schizophrenia

Temperature and humidity conditions affect the growth and success of ectotherm insects. Red wood ants of the Formica rufa group are able to regulate the temperature of their nests to be close to the optimum, typically higher than ambient in northern latitudes and higher elevation. The mound-shaped nests are constructed from organic particles (needles, sticks, etc., plant material) and from soil particles. Nest mounds typically have a relatively dry inner structure but moister surface layer which may help the ants to insulate nests against cooling winds. Forest clear felling exposes nest mounds to direct sunlight, drier microclimate and increased wind. We studied whether clear felling affects the nest surface moisture and temperature conditions. We found that i) nest surfaces were significantly drier in clear fells than in forests, ii) a high height/diameter ratio and an increase in the nest volume increases surface dryness in clear fells but not in forests, iii) the nest temperatures relative to ambient temperature was higher in forests than in clear fells, and iv) the relative temperature increased with increasing moisture content of nest surface layer. The drying nest material and more unstable inside temperature may have adverse effects not only on the red wood ants themselves, but also for nest-dwelling soil organisms and myrmecophiles that live in red wood ant nests. In addition, changes in moisture and temperature could have effects on the rate of decomposition and nutrient turnover.

Consequences of Climate Change-Induced Habitat Conversions on Red Wood Ants in a Central European Mountain: A Case Study.

Simple SummaryThe red wood ants are considered to be one of the main ecosystem engineers and keystone species of the habitats in which they exist. Most of the species from this species group inhabit coniferous forests, which, due to the consequences of anthropogenic climate change, are continuously cut down. Therefore, the main habitat of these important species is rapidly disappearing. We investigated the consequences of the absence of conifers (clear-cut area and deciduous forest) on one of the members of this species group, namely Formica polyctena. We have found that compared with the mixed-coniferous forest stand, the absence of coniferous species resulted in significant changes in the colony and nest structure of F. polyctena. In addition, the colony size was also smaller in these sites. These changes suggest that although F. polyctena is able to survive in suboptimal habitats, still their population decline is expected and urges conservation managers to apply necessary action plans for their protection.The consequences of anthropogenic climate change are one of the major concerns of conservation biology. A cascade of negative effects is expected to affect various ecosystems, one of which is Central European coniferous forests and their unique biota. These coniferous forests are the primary habitat of many forest specialist species such as red wood ants. Climate change-induced rising of temperature allows trees to skip winter hibernation, making them more vulnerable to storms that cause wind felling, and in turn, promotes bark beetle infestations that results in unscheduled clear-cuttings. Red wood ants can also be exposed to such habitat changes. We investigated the effects of bark beetle-induced clear-cutting and the absence of coniferous trees on colonies of Formica polyctena, including a mixed-coniferous forest as a reference. Our aim was to investigate how these habitat features affect the nest characteristics and nesting habits of F. polyctena. Our results indicate that, in the absence of conifers, F. polyctena tend to use different alternatives for nest material, colony structure, and food sources. However, the vitality of F. polyctena colonies significantly decreased (smaller nest mound volumes). Our study highlights the ecological flexibility of this forest specialist and its potential to survive under extreme conditions.

Study and Development of an Anthroposophical Formula Based on Phosphorus and Formica rufa for Onychomycosis´s Treatment.

Onychomycosis is a fungal infection of the nail plate or nail bed that leads to the gradual destruction of the nail. The main difficulties in the treatment of onychomycosis refer to the duration of treatments and their side effects. Thus, it becomes relevant to look for new therapeutic alternatives in the treatment of such common diseases that are efficient without causing the undesirable side effects on the patient's body. In this way, the objective of this study was to develop an anthroposophical formula for the treatment of onychomycosis, based on Phosphorus and Formica rufa, from an extensive bibliographic survey on the functions of these components, evaluating within the principles of Anthroposophy. Considering the set of knowledge and practices on the use of these components, it was possible to arrive at a proposal therapy that can be effective for the treatment of onychomycosis. After an extensive review of several existing patents, it was observed that formulations containing Phosphorus and Formica rufa together have not been described in other studies. Subsequently, our research group published a patent of the anthroposophical formula using these two components, with the number BR1020180750755, which will be efficient to help the recovery of nails, and facilitate normal growth.

Spatial cognition in the context of foraging styles and information transfer in ants.

Ants are central-place foragers: they always return to the nest, and this requires the ability to remember relationships between features of the environment, or an individual's path through the landscape. The distribution of these cognitive responsibilities within a colony depends on a species' foraging style. Solitary foraging as well as leader-scouting, which is based on information transmission about a distant targets from scouts to foragers, can be considered the most challenging tasks in the context of ants' spatial cognition. Solitary foraging is found in species of almost all subfamilies of ants, whereas leader-scouting has been discovered as yet only in the Formica rufa group of species (red wood ants). Solitary foraging and leader-scouting ant species, although enormously different in their levels of sociality and ecological specificities, have many common traits of individual cognitive navigation, such as the primary use of visual navigation, excellent visual landmark memories, and the subordinate role of odour orientation. In leader-scouting species, spatial cognition and the ability to transfer information about a distant target dramatically differ among scouts and foragers, suggesting individual cognitive specialization. I suggest that the leader-scouting style of recruitment is closely connected with the ecological niche of a defined group of species, in particular, their searching patterns within the tree crown. There is much work to be done to understand what cognitive mechanisms underpin route planning and communication about locations in ants.