Forest Ants Research Articles

Rapid assessment of the three‐dimensional distribution of dominant arboreal ants in tropical forests

Abstract Ants are omnipresent in tropical forests, especially territorially dominant arboreal ants whose territories are spatially segregated forming ‘ant mosaics’. These ecologically important species are rarely used in conservation monitoring because of the difficulty in collecting them. We developed a standardised baitline protocol to study the distribution of dominant ants on canopy trees and also a procedure to objectively define species dominance, even in unknown ant assemblages. Besides eliminating the need to climb trees, this protocol allows live arboreal ant specimens to be sampled at different heights. Behavioural aggressiveness assays between the collected workers provide data on the three‐dimensional distribution of colonies and on interactions between species. We compared the results of the behavioural tests to those from null models. In the New Guinean lowland forest studied, we show that the canopy was either shared by multiple territorial species or inhabited by a single species with a large territory. The baitline protocol collected up to half of the arboreal ant species found in a felling census. However, the proportion of species collected at baits decreased with the increasing spatial dominance of single territorial species. Behavioural observations used in the protocol allowed a more efficient detection of ant mosaics than null models. Territorially dominant ants were active on both understorey and canopy trees. The protocol is fast and easy to replicate. It is a potential tool for understanding and monitoring the spatiotemporal dynamics of arboreal ant assemblages and can detect populous colonies, including those of invasive species.

Ant-gardens: a specialized ant-epiphyte mutualism capable of facing the effects of climate change

It is suggested that specialized mutualisms are more vulnerable to climate change. Ant-gardens (AGs) are a complex and specialized mutualistic system represented by epiphytic plants that specifically inhabit the arboreal nest built by canopy ants in tropical forests. Different ant-epiphyte ensembles constitute the AGs throughout the Neotropics. However, neither the environmental factors that determine their geographical distribution nor the effects of climate change on this canopy biological system are known. Here, we estimated the ecological niche and elevational distribution of the Neotropical AGs as an entity (regardless of species composition), and individually for six AG ant and 16 AG epiphyte species in order to determine and compare their current and future distributions (vulnerability), using two unrelated Global Circulation Models for the year 2070 under two Representative Concentration Pathways (RCP4.5: optimistic and RCP8.5: pessimistic). The current potential distribution of the AGs is discontinuous from Tamaulipas, Mexico, to Rio Grande do Sul, Brazil, in low elevation areas with high mean annual temperatures (> 25 °C) and precipitation (> 2400 mm). In contrast, the individual distributions of the AG ants and epiphytes tended not to follow to this climatic profile and were segregated by both latitude and elevation. The geographic distribution of most AG ant and epiphyte species diminished under climate change, while that of the AGs increased, even under the pessimistic scenario. This suggests that AGs allow the species that comprise them to broaden their ecological niche and be more resistant to climate change than they would be outside of this system.

Plasticity in extended phenotypes: how the antlion Myrmeleon crudelis adjusts the pit traps depending on biotic and abiotic conditions

Abstract The physical structures built by animals are considered extended phenotypes that reflect how organisms make decisions and deal with changes in their biotic and abiotic environment. We summarize the results of several studies on Myrmeleon crudelis, a neuropteran larva that digs pit-traps in the soil to capture small arthropods (mostly ants) in the tropical dry forests of Costa Rica. Specifically, we showed how this species responds to varying biotic and abiotic conditions with changes in the design and/or location of its pit traps. Several experiments and field comparisons indicate that: 1) antlions adjust the pit design according to the abundance and type of prey. When prey is scarce, antlions increased trap diameter, an architectural adjustment that enhances the probability of prey encounter. Antlions that experienced high prey abundance, but the prey easily escaped, then increased pit depth, an adjustment that increases the chance of prey retention; 2) soil compaction strongly reduced pit-trap size and abundance; 3) antlions preferred soils with high proportion of fine-particle size to build pits. In fine-grained soil, pit-traps are larger and more efficient to capture prey than traps in coarse-grained soils; and 4) pit-traps may also be affected through indirect effects of soil structure and vegetation cover. Areas with fine-soil presented less plant cover, and plant cover could be beneficial for antlions because it acts as a shelter against direct sunlight and rainfall, or it may represent a cost because it is a source of leaflitter falling in the pits. The works summarized here how trap-building predators can exhibit considerable flexibility in trap construction in response to various biotic and abiotic factors, emphasizing how the study of extended phenotypes can be a useful approach to better understand the flexibility of foraging behaviors.

Prospects for biological methods of controlling oak pests

The article presents the results of experimental evaluation of biological control measures against oak adelgid, striking a young oak effectiveness. The material for the study were the young shoots of pedunculate oak (Quercus robur L.) affected Stomaphis quercus L.. The work was carried out on the basis of Undorovsky forest district of the Ulyanovsk region from May to September 2019. In the study area a detailed survey of the plantings for the major taxonomic characteristics was conducted. In determining the class status of the oak forests forest pathology technique was used. A forested area with the lowest productivity of young plantations was divided into 3 sample areas: the area of control; the area treated with biological product Bicol; the area of settlement of red ants. The area of each zone averaged 0,333 ha. In each of the trial sites 110 instances model trees affected by oak adelgid were selected, at the age of 10 years, with an average diameter of from 2 to 2.2 cm and a height of from 1.8 to 2.3 m, which were based on the number of this pest. The abundance of oak adelgid was calculated on the most populated internodes or on the whole tree, specifying the degree of damage to the tree. The dependence of the sanitary state of trees on the average number of pests has been established. The effectiveness of the biological product Bicol was 16.0 - 44%, depending on the duration of the experiment. Evaluation of the effectiveness of using red forest ants as a biological method for protecting young oak forests from Stomaphis quercus L. throughout the summer season allowed us to identify a growing trend in performance: from 10% in June to 20% in August, which suggests the relative stability of the developed biological protection system for young oak grove. The above statistical analysis confirms the positive effect of the use of the biological product Bikol and the promising nature of the method with the resettlement of red forest ants.

Distribution of epigeic and hypogeic ants (Hymenoptera: Formicidae) in ombrophilous forests in the Brazilian Amazon

In the Amazon basin, ants are often associated with environmental or edaphic factors. However, these associations may vary between the epigeic and hypogeic strata. Here, we investigated differences in richness and composition of epigeic and hypogeic ant assemblages along an environmental gradient in the Brazilian Amazon. The four studied sites cover different topographic and soil characteristics. We sampled 25 plots of 250 m2 using 10 samples of epigeic pitfalls and 10 samples of hypogeic pitfalls installed at two depths (10 and 30 cm). The pitfalls remained in the fi eld for 48 hours. In the same plots, soil clay content and terrain altitude were also measured. We collected 219 species or morphospecies, of which 14 were exclusively hypogeics. We found higher local richness in the epigeic compared to hypogeic assemblages. We also found an interaction between clay content and strata for ant species composition. Overall, the species turnover was related to clay content, but the eff ect depended on the strata, with hypogeic fauna being more heterogeneous, compared with epigeic fauna. Despite the relationship between clay content and ant´s assemblage’s composition, we did not find strong environment predictors for both strata, which suggests that other factors may structure ant assemblages in these sites. This reinforces the need for studies to defi ne which environmental gradiente determines the distribution of Amazonian epigeic and hypogeic ants.

Impacts of Tractor Logging on the Diversity of Ground Ants (Hymenoptera: Formicidae) in Natural Production Forest of Central Borneo

Tractor logging in tropical forest concession disturbs the life of soil surface organisms, including ground ant. Ground ant has an important role in determining soil fertility. The study aimed to analyze the impact of tractor logging on the diversity of ground ant (Hymenoptera, Formicidae) in the natural production forest. Two transect lines of 100 m length and 200 m distance between lines were placed in four different cutting compartments, i.e., currently logged, one month after logging, two months after logging, and unlogged. Ground ant was collected using a pitfall trap. The environmental factors (density of understorey plants, canopy cover, soil compaction, litter thickness, temperature, and humidity) were measured at the setting location of pitfall trap. Analysis of variance (ANOVA) was used to determine the mean difference between treatments. Pearson correlation test was used to determine the correlation between insect abundance and environmental factors. The results of the study indicated that there was a significant difference in the abundance of the ground ant after logging and before logging. The abundance of ground ants after logging was lower than before logging. The abundance of ground ants among skidded plots was not significantly different. Soil compaction due to tractor logging, litter thickness, and temperature did not significantly affect the abundance of ground ants. The ground ant composition did not change due to tractor logging.Keywords: environment impact, forest conservation, forest disturbance, forest ecosystem

Effects of seed morphology and elaiosome chemical composition on attractiveness of five Trillium species to seed-dispersing ants.

Morphological and chemical attributes of diaspores in myrmecochorous plants have been shown to affect seed dispersal by ants, but the relative importance of these attributes in determining seed attractiveness and dispersal success is poorly understood. We explored whether differences in diaspore morphology, elaiosome fatty acids, or elaiosome phytochemical profiles explain the differential attractiveness of five species in the genus Trillium to eastern North American forest ants. Species were ranked from least to most attractive based on empirically‐derived seed dispersal probabilities in our study system, and we compared diaspore traits to test our hypotheses that more attractive species will have larger diaspores, greater concentrations of elaiosome fatty acids, and distinct elaiosome phytochemistry compared to the less attractive species. Diaspore length, width, mass, and elaiosome length were significantly greater in the more attractive species. Using gas chromatography–mass spectrometry, we found significantly higher concentrations of oleic, linoleic, hexadecenoic, stearic, palmitoleic, and total fatty acids in elaiosomes of the more attractive species. Multivariate assessments revealed that elaiosome phytochemical profiles, identified through liquid chromatography–mass spectrometry, were more homogeneous for the more attractive species. Random forest classification models (RFCM) identified several elaiosome phytochemicals that differed significantly among species. Random forest regression models revealed that some of the compounds identified by RFCM, including methylhistidine (α‐amino acid) and d‐glucarate (carbohydrate), were positively related to seed dispersal probabilities, while others, including salicylate (salicylic acid) and citrulline (L‐α‐amino acid), were negatively related. These results supported our hypotheses that the more attractive species of Trillium—which are geographically widespread compared to their less attractive, endemic congeners—are characterized by larger diaspores, greater concentrations of fatty acids, and distinct elaiosome phytochemistry. Further advances in our understanding of seed dispersal effectiveness in myrmecochorous systems will benefit from a portrayal of dispersal unit chemical and physical traits, and their combined responses to selection pressures.

Warmer mid-day temperatures increase leaf intake by increasing forager speed and success in Atta colombica during the rainy season

Predicting the effects of climatic warming on social insects remains an important challenge. While warming is known to speed many rate processes, the acute effects of temperature on performance under field conditions remain poorly studied. The effects of temperature are usually nonlinear, and tropical animals have been predicted to be particularly likely to be negatively affected by global warming as they may have optimal temperatures that are close to current ambient temperatures. We observed three different A. colombica colonies three times per day (two times during daylight hours and one time at night) during June 2018 in Gamboa, Panama, measuring air temperature, ant traffic, intake of leaves per second, and ant walking speeds. We found that ant walking speed and intake of leaves increased at higher temperatures. Leaves carried per ant also increased with temperature, suggesting that warmer temperatures improve leaf-handling rates, at least over the thermal range studied here. However, there was also an independent effect of time of day, with higher foraging in the morning than the evening, despite similar air temperatures. Consistent with the positive effect of temperature on foraging rates, critical thermal maxima were well above ground temperatures. At least during the rainy season, our data suggest that moderate warming could enhance foraging success and herbivory of leafcutting ants in semi-deciduous moist forests throughout much of the day.

Diaspore Abundance Promotes more Interaction with Ants in a Brazilian Atlantic Forest

Abstract The influence of Guarea guidonia (L.) Sleumer diaspore abundance on ants’ preference was studied in a secondary tropical forest area in Brazil. We offered seeds in stations with different abundances (one, two, five or 10 diaspores) for interactions with ants. The number of interactions and of ants were influenced by diaspore abundance during the observation period. Stations with 10 diaspores maintained a high number of interactions throughout the experiment. Incidence of seed cleaning differed among the four groups. Moreover, the number of interactions was positively related to the average percent of seeds cleaned. Diaspore abundance proved to be important for promoting more interactions with ants. Considering that the proportion of seeds cleaned increased with the number of interactions, further experiments should observe ant activity for a longer period. Furthermore, diaspore abundance should be considered in future studies of interactions with ants.

Foraging and Daily Activity Features of Ants of the Genus Formica (Insecta, Hymenoptera) in Forest–Steppe Biotopes of Saratov Oblast

This paper presents the results of our research on the foraging activity of ants in forest–steppe biotopes of Saratov oblast. The food spectrum of ants was found to include small invertebrates (mainly insects), plant seeds, and aphid honeydew. Ants are able to switch to the most massive type of food. F. pratensis behaves as a species with a daytime or morning–evening activity type, depending on the weather conditions. F. rufa is a species with a daily activity type.

Gall-Colonizing Ants and Their Role as Plant Defenders: From 'Bad Job' to 'Useful Service'.

Galls are neoformed structures on host plant tissues caused by the attack of insects or other organisms. They support different communities of specialized parasitic insects (the gall inducers), and can also provide refuge to other insects, such as moths, beetles and ants, referred to as secondary occupants. This study focuses on galls induced by the oak gall wasp Andricus quercustozae and secondarily colonized by ants in a mixed oak forest. A field survey and two experiments were carried out to a) study ant (species-specific) preferences for different features of the galls, b) describe differences in gall architecture due to ant activity, c) analyse the effects of the presence of gall-dwelling ants on plant health. The results show that there are differences between ant species in gall colonization and in the alteration of gall opening and inner structure. We verified that gall-dwelling ants protect their host plants efficiently, offering them an indirect defence mechanism against enemies (predators and pathogens). The data suggest a new paradigm in ant–plant relationships mediated by the presence of galls on the plants whose ecological and evolutionary implications are discussed.

Comparative evaluation of taxonomic and functional diversities of leaf-litter ants of the Brazilian Atlantic Forest

The ant community living in leaf litter was assessed in 65 forest sites in the Brazilian Atlantic rainforest in the southern region of the state of Bahia, Brazil. In addition, we aimed to understand the patterns between taxonomic and functional diversities using two different resolutions of classification of ants into functional groups. We identified 364 ant species belonging to 68 genera in 10 subfamilies in 65 regions. Considering a more general functional classification, we identified a total of 13 functional ant groups, and 26 functional ant groups considering a more specific functional classification. The Atlantic Forest environments studied presented great taxonomic ant diversity. We observed that ant species richness and the number of functional groups are not closely related metrics, especially when considering a more general functional classification. Moreover, even when considering a more specific functional classification, the relationship with ant richness is only moderate. These results suggest that the number of species in a given group does not necessarily reflect the role played by that group within the environment. Integrating different biodiversity perspectives is crucial for the successful conservation of the Atlantic Forest ants.

Do Workers from Subspecies Acromyrmex subterraneus Prepare Leaves and Toxic Baits in Similar Ways for Their Fungus Garden?

Toxic baits are the most efficient method to control leaf-cutter ants in eucalyptus forests for paper and cellulose production. For the proper use of these baits, insecticide compounds must reach workers and contaminate them. Thus, understanding how these baits are processed inside the nests is vital for a successful control, especially when it comes to genus Acromyrmex. Lack of information on toxic baits and on contamination of Acromyrmex workers raises the question: do workers from subspecies Acromyrmex subterraneus (Forel) prepare leaves and toxic baits in similar ways for their fungus garden? To answer it, this study described and analyzed the behavioral repertoire executed by A. subterraneus workers during the preparation of leaf disks and baits and their incorporation into the fungus garden. Results show that the act of licking the substrate was the most frequently executed behavior, regardless of subspecies or size categories. Moreover, additional behaviors have been observed when workers processed the baits, such as licking and scraping their jaws on the surface of the bait pellet, as well as licking and biting fragments of bait pellets, moistening them. Thus, it is concluded that the preparation of baits is different from that of leaves; baits are more processed and can therefore contribute to contaminating workers via insecticides.

To boldly go where no one has gone before in organ transplantation: Changes in mating behaviour and buffalo burger eating preferences of giant forest ants after successful brain transplant from American cockroaches

The implications of ambimorphic archetypes in organ transplantation have been far-reaching and pervasive. After years of natural research into consistent hashing, we argue the simulation of public-private key pairs, which embodies the confi rmed principles of theory. Such a hypothesis might seem perverse but is derived from known results. Our focus in this paper is not on whether the well-known knowledge-based fact that humans breathe through their mouth or nose and the brain controls that critical function, so breathing would stop. The hardy vermin breathe through spiracles, or little holes in each body segment. Plus, the roach brain does not control this breathing and blood does not carry oxygen throughout the body. Overall, a new approach in succesful brain transplant have been developed.

Die Verbreitung der Waldameisen in den Kantonen Basel-Landschaft und Basel-Stadt

Distribution of forest ants in the cantons of Basel-Landschaft and Basel-Stadt In 2015 and 2016, the forest service of the two Basel cantons and the nature protection service of Basel-Landschaft made an inventory of the distributions of forest ants, by mapping systematically the location of anthills. In total, 1757 anthills were found, which is estimated at two thirds of the real number of anthills. The presence of five species of domestic forest ants was demonstrated. The two most common species, Formica rufa and F. polyctena are mostly at medium altitude in Basel-Landschaft. As expected the nests of F. lugubris and F. paralugubris are found overwhelmingly at high altitude. The anthills of F. pratensis are mostly found in open habitats. The know ledge obtained through this mapping on the distribution of these species will make possible a targeted approach to protecting the nests. In addition, these results will serve as a baseline for future research, and represent a significant contribution to knowledge of fauna in Switzerland.

Культ огня в охотопромысловой деятельности и бытовой культуре тунгусо-маньчжурских этносов Нижнего Амура и Приморья

The article discusses the problem of ethnic mysteries connected with the worship of the fire cult of the Tungus-Manchurian ethnic groups of the Far East based on field published materials and literary sources. The relevance of the research goal is determined by the scientific and public interests of the small indigenous peoples of the Amur region, Primorye and other regions of Russia. This goal is achieved by a detailed study of numerous rituals, prohibitions and signs that are directly related to hunting and the everyday culture of the fishing population of the Tungus-Manchu ethnic groups. According to the worldview of the Nanai, Negidal, Orochi, the article was prepared taking into account ethnological research methods and ethnographic approaches such as visual observation and personal involvement in the mysteries associated with the rituals of worship, feeding the “god” of fire Pudza and the request of the hunters from the master of the taiga Onku a successful hunt. Ulchi, Udege and other Tungus-Manchurian ethnic groups of the southern part of the Russian Far East, it was believed that the fire master Pudza Ezani had the toad of Jala (guarding the fire from self-extinguishing), Ikte forest ants, who helped the toad, to maintain a “good” fire, as well as the Sugdugu bird - the kingfisher – the servant of the ant host Ikta Ezani, and the wild boar Aulа, who was the first in the taiga to report insane fire (fire) that escaped the host's control. All traditional life, hunting, fishing and gathering of the Tungus-Manchu ethnic groups of the Lower Amur and Primorye were associated with the worship and preservation of old rituals and traditions of the ancient ancestors, who laid the economic and cultural basis for the existence of their descendants.

Predation of top predators: cane toad consumption of bullet ants in a Panamanian lowland wet forest

Abstract:Despite a clear consensus about the major roles that predators play in shaping ecological communities, descriptive studies of interactions between ecologically important top predator species are underreported. Native cane toad consumption of predatory bullet ant nests was verified through multiple, independent observations taken on Pipeline Road, Panama. Cane toad predation led to the extirpation of 42% of the nests within a 1.05 km2area that is characterized as a late-successional wet forest. This predation pressure could be significant given the high rate of predation events and low bullet ant nest density observed here (0.12 nests ha−1). Implications of this interaction for the local bullet ant population, possible top-down effects and trophic cascades resulting from this top predator interaction are discussed.

Human disturbance promotes herbivory by leaf‐cutting ants in the Caatinga dry forest

AbstractAnthropogenic disturbances are known to modify plant–animal interactions such as those involving the leaf‐cutting ants, the most voracious and proliferating herbivore across human‐modified landscapes in the Neotropics. Here, we evaluate the effect of chronic anthropogenic disturbance (e.g., firewood collection, livestock grazing) and vegetation seasonality on foraging area, foliage availability in the foraging area, leaf consumption and herbivory rate of the leaf‐cutting ant Atta opaciceps in the semiarid Caatinga, a mosaic of dry forest and scrub vegetation in northeast Brazil. Contrary to our initial expectation, the foraging area was not affected by either disturbance intensity or the interaction between season and disturbance intensity. However, leaf consumption and herbivory rate were higher in more disturbed areas. We also found a strong effect of seasonality, with higher leaf consumption and herbivory rate in the dry season. Our results suggest that the foraging ecology of leaf‐cutting ants is modulated by human disturbance and seasonality as these two drivers affect the spectrum and the amount of resources available for these ants in the Caatinga. Despite the low productivity of Caatinga vegetation, the annual rates of biomass consumption by A. opaciceps are similar to those reported from other leaf‐cutting ants in rain forests and savannas. This is made possible by maintaining high foraging activity even in the peak of the dry season and taking benefit from any resource available, including low‐quality items. Such compensation highlights the adaptive capacity of LCA to persist or even proliferate in human‐modified landscapes from dry to rain forests.

Comparison of ant-associated beetle communities inhabiting mounds of forest-dwelling ants in forests and forest clearings

Red wood ant (Formica rufa group) nests contain a highly diverse community of invertebrates, which is largely due to their abundant resources and regulated microclimatic conditions. Clear-felling, however, causes nest mounds to lose surface layer moisture, thus disrupting their inner stability. To study the effects of clear-felling on ant-associated beetles (myrmecophile and non-myrmecophile), 41 nests of Formica aquilonia Yarrow, 1955 located on three clear-fells and adjacent mature forest stands were sampled, and the beetle communities between these habitats were compared. We investigated how habitat type, nest surface moisture content, nest volume, and isolation affect the community composition, species richness, and abundance of beetles. Beetle community composition or species richness did not markedly differ between clearings and forests, although total abundance was higher in forests. Also, total species richness and abundance and myrmecophile abundance increased with increasing moisture content. Overall, nests with similar moisture content and volume had similar species compositions. Nest volume was negatively correlated with myrmecophile species richness. Nest isolation was not related to species richness or abundance. The lower abundances in clearings could be problematic in the long term, as small populations are more likely to become extinct. To ensure the survival of ants and their associates, small-scale clearings should be preferred.

No difference in ectomycorrhizal morphotype composition between abandoned and inhabited nests of wood ants (Formica polyctena) in a central European spruce forest

In temperate forest ecosystems, ectomycorrhizal (EcM) fungi substantially support coniferous trees by nutrients, but importance of EcM for tree nutrition might be lower in nutrient-rich hotspots, such as in wood ant nests. In this study, we focused on differences in EcM morphotype composition between natural nutrient-rich hot spots of various quality (inhabited vs. abandoned wood ant nests) and the surrounding forest floor. In a secondary Norway spruce forest typical for central Europe, we took samples from different belowground parts of five inhabited and five abandoned nests (centre and rim) as well as from the forest floor 20 cm from the nests (run-off zone) and >3 m from the nests (forest soil). The substrates were subjected to analyses of the EcM morphotype composition, moisture and nutrient contents. Wood ant nest substrates had several times increased nutrient contents compared to the forest soil, but there were no significant differences in moisture. Available nutrient contents were higher in inhabited nests than in abandoned nests. The EcM morphotype composition differed between the nest samples and the forest floor samples but not between the inhabited and abandoned nests suggesting that, apart from the level of nutrient enrichment and their availability, moisture is another important factor affecting EcM community composition.