Subterranean Nests Research Articles

Swimming through sand: using accelerometers to observe the cryptic, pre-emergence life-stage of sea turtle hatchlings.

Animals that hatch within a subterranean nest, such as turtle hatchlings, expend some of their limited energy reserves digging out through sand or soil to reach the surface. In sea turtles, this emergence process can take the hatchlings 3-7 days. However, we have a poor understanding of this process as it is difficult to observe what is occurring underground. Here, we utilize a novel method to characterize digging-out behaviour: affixing an accelerometer directly to newly hatched green turtles (Chelonia mydas) to record movement until nest emergence. Our data revealed that buried hatchlings maintained a head-up orientation but did not move in the expected left and right swaying motion associated with alternating limb crawling. Rather, they moved using dorsal-ventral heaving and pitching as if swimming vertically through the sand to the surface. Movement activity was irregular and brief, interspersed by many short periods of inactivity, mostly lasting less than 10 min. The first 24 h of head-up activity displayed no diel patterns, but the last 24 h prior to emergence involved more intense movement during night-time hours compared with daytime hours. Thus, our results add valuable new insight, and in some cases change previous assumptions, regarding the digging behaviours during the egg-to-emergence life stage in sea turtles.

Subterranean termite nests in residential and open crop fields in central Ethiopia: Knowledge and perception of farmers on causes and effects

This study aimed to assess subterranean termite nests in residential and open crop fields in Central Ethiopia: knowledge and perception of farmers on causes and effects. A descriptive research design was used for primary data collection from the selected district of central Ethiopia. Termite nests were counted from each kebele after clustered into local division called Gox. A total of 72 sampling frames with a 1 km2 were used for termite nests count. In addition, 190 household heads were selected at random from each kebele for questionnaires survey. Termite nests were abundant in Warabo (7.251.71 per 1000 m2), but scarce in Warke Walensu Kebele (2.250.50 per 1000 m2). Teff (49.5%) and wheat (32.6%) were the crops most severely affected by termites. The mean annual hectares of land and quintals of teff and wheat damaged per household were higher in Warabo Kebele (p = 0.000) and lowest in Warke Walensu Kebele. The annual economic loss from crops loss due to termite's effect was greater in Warabo Kebele (4722.23 ± 869.67 ETB and 4396.43 ± 852.65 ETB from teff and wheat per household, respectively). Agroecology, deforestation, grazing, and crop type were the factors that determine termite abundance and its impact on farmers' livelihoods. Mound opening and smoking were the traditional management methods used, but there was no government support. Therefore, integrated and effective termite pest management is critical for long-term food security in the study area.

Retinestatin, a Polyol Polyketide from a Termite Nest-Derived Streptomyces sp.

A new polyol polyketide, named retinestatin (1), was obtained and characterized from the culture of a Streptomyces strain, which was isolated from a subterranean nest of the termite Reticulitermes speratus kyushuensis Morimoto. The planar structure of 1 was elucidated on the basis of the cumulative analysis of ultraviolet, infrared, mass spectrometry, and nuclear magnetic resonance spectroscopic data. The absolute configuration of 1 at 12 chiral centers was successfully assigned by employing a J-based configuration analysis in combination with ROESY correlations, a quantum mechanics-based computational approach to calculate NMR chemical shifts, and a 3 min flash esterification by Mosher's reagents followed by NMR analysis. Biological evaluation of retinestatin (1) using an in vitro model of Parkinson's disease revealed that 1 protected SH-SY5Y dopaminergic cells from MPP+-induced cytotoxicity, indicating its neuroprotective effects.

Removal of chromate in aqueous solutions by termite nests and reduction chromate accumulation in Brassica chinensis L.

Chromate [Cr(VI)] is a highly toxic heavy metal element, representing one of the most prevalent sources of wastewater contamination. It poses a significant threat to human health and food safety. Therefore, effective treatment before discharging wastewater is of paramount importance. In this study, termite nests (Coptotermes formosanus and Odontotermes formosanus), as natural biomass materials, were used to adsorb Cr(VI) ions in wastewater as a strategy to reduce environmental pollution and minimize poisoning by Cr. Structural and morphological characterizations were performed using scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. Batch adsorption experiments were conducted to evaluate the influence of termite nest dosage, coexisting ions, and pH. To gain further insight, detailed studies on adsorption kinetics, adsorption isotherms, and adsorption thermodynamics were undertaken. The results indicate that under acidic pH conditions, both termite nests exhibit the highest adsorption capacity for Cr(VI), with an optimal adsorbent dosage of 10 g/L. The maximum adsorption capacities of C. formosanus nest and O. formosanus nest for Cr(VI) were found to be 48.52 mg/g and 35.99 mg/g, respectively. Thermodynamic studies confirmed the spontaneous and endothermic nature of the adsorption process. In the rapeseed cultivation experiment, the growth status of Brassica chinensis L. post-adsorption treatment was markedly improved compared to the untreated group. Additionally, the concentration of Cr(VI) in the plants was significantly reduced. This demonstrates both the inhibitory effect of Cr(VI) on the growth of oilseed rape and the effectiveness of water remediation techniques. In addition, both types of termite nests can be effectively reused by 0.1 mol/L HCl. To the best of our knowledge, this is the first report of adsorption removal of Cr(VI) by C. formosanus nest and O. formosanus nest. Compared to traditional natural biomass adsorbents, termite nests exhibit a relatively higher adsorption capacity for Cr(VI). The results of this study demonstrate that subterranean termite nests can efficiently remove Cr(VI) from wastewater, offering the potential for a cost-effective and reusable bioremediation agent with the advantages of ease of operation.

Defensive phragmosis and cathaptosis in Trichoptera larvae

Phragmosis, or the use of specially modified body parts and associated behaviors to block an opening as defense against predators, is a commonly observed phenomenon in certain ants and termites that block entrances of their subterranean nests with large, flat heads. It has been reported in some beetles and other insects and even in some frogs. Common features of phragmosis in caddisfly larvae include a hard and usually flat body surface, with or without stout spines, and the behavior of fitting that body surface tightly in the opening of its case. A different defensive strategy occurs in snails and case-making larvae of camptosomate leaf beetles (Chrysomelidae: Cryptocephalinae and Lamprosomatinae) that protect themselves from predators by securing the openings of their shells or cases firmly against the substrate, a behavior we call “cathaptosis.” Common features of cathaptosis in caddisfly larvae include a case with its vulnerable opening oriented parallel with the substrate and accompanied by behavior that grips the substrate, fixing the case opening firmly against it when threatened. We suggest that these defensive strategies have evolved multiple times in Trichoptera, especially in case-making larvae. We demonstrate some examples and provide tentative lists of caddisflies whose larvae may have evolved these defensive strategies.

Foraging behaviour affects nest architecture in a cross-species comparison of ant nests.

Animals construct and inhabit nests that can exhibit dramatic intra- and interspecific variation due to differences in behaviour, the biotic and abiotic environment, and evolutionary history. In ants, variation in nest architecture reflects both differences in ecology and in the collective behaviour of the colonies that live in the nests. Each component of the nest (such as depth, and the number, size and connectivity of chambers) reflects selective pressures for different functions, or structural constraints that are imposed by the environment or evolutionary history. To determine potential drivers of nest structure variation in subterranean nests, we performed a meta-analysis of measures of published ant nests to compare different structural elements within and across species. We complemented this survey with 42 nest casts of two closely related species. We quantified nest features that can potentially impact ant foraging behaviour and examined whether phylogeny or foraging strategy are better explanatory variables for the variation we observed. We found that foraging strategy better explained nest features than evolutionary history. Our work reveals the importance of ecology in shaping nest structure and provides an important foundation for future investigations into the selective pressures that have shaped ant nest architecture. This article is part of the theme issue 'The evolutionary ecology of nests: a cross-taxon approach'.

Composition of different castes in the subterranean termite Odontotermes horni (Wasmann) nest

An investigation was conducted at GKVK in Bengaluru, India, to study the composition of subterranean termite nests built by Odontotermes horni. The study revealed that eggs were found in groups on the primary depository, while nymphs of workers, soldiers, and alates were observed in the fungus combs. The nymphs formed most of the colony population, with workers being more numerous and dimorphic with major and minor forms. Soldiers were found to be associated with the workers as guards during various activities. The royal pair (king and queen) was situated in the royal chamber, with two queens and a king observed in one of the nests. The king and physogastric queen measured 12.6 and 61.5 mm in length, respectively. Adult alates were seen in the alate waiting chamber before emergence.

Design and architecture of the subterranean nest of Odontotermes horni (Wasmann).

Odontotermes horni constructed the earthen sheetings using the sub-soil on the food sources externally while foraging. The nest distributed in 7.50 to 9.24 sqm area. The fungal chambers varied in size, distributed in a multilocular fashion from 32 to 150 cm below the ground. The giant fungal chamber near the royal chamber serves as the primary depository. The royal chamber was simple, located at 70.6 to 95.5 cm below the ground, more or less in the central region of the nest. Incubation cavities were present below the royal chamber. A flat alate waiting chamber was located 46 cm below the ground.

The Potential of Fluralaner as a Bait Toxicant to Control Pest Yellowjackets in California.

The western yellowjacket, Vespula pensylvanica (Saussure), is an important seasonal pest of recreational and outdoor venues in the western United States. Its propensity to scavenge food increases the likelihood of stinging incidences. Control measures are limited to intensive trapping and treating subterranean nests. The only toxicant registered for baiting in the US is esfenvalerate, which is ineffective. The objective of this study was to determine the potential of the isoxazoline fluralaner as a bait toxicant. With microsatellite genotyping, a minimum of 27 different colonies were shown to forage at a single monitoring site. Some colonies disappeared after baiting, and new colonies were detected. The implications for baiting and monitoring are discussed. Minced chicken and hydrogel baits containing 0.022% and 0.045% fluralaner significantly reduced foraging yellowjackets. Several bait applications covering large areas will be necessary to provide long-term control.

Construction of nest mound and preference for it during relocation in an Indian ant Diacamma indicum

Abstract Ants living in subterranean nests face the challenge of nest flooding and require to combat this recurring issue. The tropical Ponerine ant species, Diacamma indicum, living in simple nests with a single chamber, was used in the current study to examine mound building in the lab. Upon stimulating rain ( colonies) they built significantly larger nest mounds as compared to controls. Nest mounds proved to be important to colonies that had experienced rain while relocating. Relocating colonies showed significantly higher preference for new nests with mounds (12/13) when choosing between two equidistant, similar quality potential new nests in contrast to control relocations. To the best of our knowledge this study for the first-time documents mound building behaviour in any Ponerine species in laboratory conditions and introduces nest mounds as another architectural feature of interest to relocating colonies.

Vertical distribution of spiders (Araneae) in Central European shallow subterranean habitats

Shallow subterranean habitats are among the last habitats in Central Europe to be arachnologically researched. Using stratified pipe traps, we studied the vertical distribution of spiders in soil and interspaces in bedrock (shallow subterranean habitats). Specifically, we sampled fauna in different substrates, including limestone, sandy marlstone, sandy marl, claystone, loess, and artificial gravel accumulation. Employing stratified pipe traps allowed us to identify the depth at which particular species occurred. Across multiple years and sampling sites, we collected 76 spider species, 21 of which showed an affinity for subterranean microhabitats. Some of these species occurred in interspaces in soil and bedrock, whereas others have been previously found in subterranean ant nests and animal burrows. We collected five species (Iberina microphthalma, Centromerus cf. piccolo, Porrhomma cambridgei, P. microcavense, and P. microps) almost exclusively at depths over half a meter, suggesting the strong affinity of these species for a subterranean lifestyle. We provide diagrams of these species’ vertical distribution and photo-document eye reduction. Our study demonstrates that poorly studied shallow subterranean habitats harbor diverse subterranean spider fauna, including several previously considered rare species in Central Europe.

A Review of Ant Nests and Their Implications for Architecture

This paper discusses the latest progress in research on ant nests and explores innovative scientific concepts associated with underground ant nests from the perspective of bionics. The methods used by scholars to study the structure of ant nests and the interaction between the structure itself and the individual ants are investigated. The structural characteristics of the ant nest, its internal environment and ventilation characteristics are discussed in detail. In addition, this paper presents an innovative project in which the effect of underground ant nests on soil geotechnical properties and the effect of calcined ant nest soil powder, from the perspective of civil engineering, are addressed. Practical examples of the application of the structural and inter-relational aspects of subterranean ant nests in the field of architectural bionics are also provided, from the perspectives of construction, morphology, function and material. This review attempts to integrate civil engineering, architecture and biology, enlighten architects and biologists on converging their thinking, provide new ideas regarding underground ant colony nests, and provide references for long-term human habitation.

Hatchling vocalizations and beneficial social interactions in subterranean nests of a widespread reptile

Signals are fundamental to communication, and theory suggests signals may evolve to coordinate cooperation on complex tasks. Several recent studies have demonstrated that hatchling turtles vocalize within the subterranean nest cavity, and these vocalizations are hypothesized to promote hatching synchrony and coordinate emergence from subterranean nests (social facilitation hypothesis). Here we test assumptions and predictions of the social facilitation hypothesis in the snapping turtle, Chelydra serpentina, a species with a broad distribution. First, we demonstrate that C. serpentina hatchlings have a vocal repertoire: we identified six types of vocalizations in a simulated nest environment, with one vocalization type occurring before egg pipping and all six types occurring in the 24 h following egg pipping and hatching. We found that Simpson's diversity was greater for vocalizations during the hatching stage compared to the emergence stage and was minimal during the prepipping stage. Second, we manipulated egg burial depth (shallow or deep) and sociality (presence or absence of siblings) in a 2 × 2 factorial design. We found that eggs in the social treatment hatched earlier and lost less mass while emerging from the nest, underlining a likely energetic benefit to hatchlings emerging with siblings versus emerging alone. Third, we tested a subhypothesis of the social facilitation hypothesis, which is that embryos cue hatching in response to hatchling vocalizations. However, vocalization playback to late-stage (prepipping) embryos did not alter pipping date relative to controls. Our combined results provide some support for the social facilitation hypothesis: there are likely energetic benefits to group emergence, embryos in a group hatch earlier, but earlier group hatching is not cued by vocalizations per se. Our study contributes to a growing literature on the adaptive significance of sociality in reptiles and helps disentangle the proximate drivers of vocalizations in hatchling turtles.

Unexpected costs of extended phenotypes: nest features determine the effect of fires on leaf cutter ant's demography.

A key principle of the extended phenotype concept is that the benefit of the structures that an animal builds exceeds its cost. However, some contexts may enhance the costs of structures that often represent a benefit, reversing their adaptive nature. In leaf-cutting ant nests, thatched mounds are extended phenotypes that offer a stable microclimate for the growth of the fungus culture. We hypothesized that fires will affect the species that build external, easily flammable thatch mounds (Acromyrmex lobicornis) more than colonies that build subterranean nests in the less-flammable bare ground (Amoimyrmex striatus). We use a stochastic matrix demographic model parameterized with 4 years of data in pre- and post-fire scenarios. Before fires, Ac. lobicornis showed higher stochastic population rate (λs) than Am. striatus. However, fire frequency every 2 years completely reversed this trend, showing population decline only in Ac. lobicornis. Small nests were the stage that most contributed to λs and the most sensitive in all the species and fire scenarios. This illustrates a novel effect of disturbances; the reversion of the adaptive nature of extended phenotypes, which may have strong consequences on population dynamics and assemblage structure through the invert of dominance relationships.

Ant nest architecture is shaped by local adaptation and plastic response to temperature

Social insects are among the most abundant arthropods in terrestrial ecosystems, where they provide ecosystem services. The effect of subterranean activity of ants on soil is well-studied, yet little is known about nest architecture due to the difficulty of observing belowground patterns. Furthermore, many species’ ranges span environmental gradients, and their nest architecture is likely shaped by the climatic and landscape features of their specific habitats. We investigated the effects of two temperature treatments on the shape and size of nests built by Formica podzolica ants collected from high and low elevations in the Colorado Rocky Mountains in a full factorial experiment. Ants nested in experimental chambers with soil surface temperatures matching the local temperatures of sample sites. We observed a plastic response of nest architecture to conditions experienced during excavation; workers experiencing a high temperature excavated deeper nests than those experiencing a cooler temperature. Further, we found evidence of local adaptation to temperature, with a significant interaction effect of natal elevation and temperature treatment on nest size and complexity. Specifically, workers from high elevation sites built larger nests with more tunnels when placed in the cool surface temperature treatment, and workers from low elevation sites exhibited the opposite pattern. Our results suggest that subterranean ant nest architecture is shaped by a combination of plastic and locally adapted building behaviors; we suggest that the flexibility of this ‘extended phenotype’ likely contributes to the widespread success of ants.

Nidicolous mites associated with Bombus niveatus Kriechbaumer (Hymenoptera, Apidae) in Iran

We collected mites from a subterranean nest (80 cm deep) of the snowy bumble-bee Bombus niveatus Kriechbaumer, in the Sabalan Mountains, Iran. The following five mite species were identified: Parasitellus fucorum, Kuzinia laevis, Proctolaelaps longisetosus, Pneumolaelaps colomboi, Pneumolaelaps hyatti. Of them, the most abundant species was Pneumolaelaps hyatti. Here in, various and some useful information about each species are discussed.

Developmental programming of DNA methylation and gene expression patterns is associated with extreme cardiovascular tolerance to anoxia in the common snapping turtle

BackgroundEnvironmental fluctuation during embryonic and fetal development can permanently alter an organism’s morphology, physiology, and behaviour. This phenomenon, known as developmental plasticity, is particularly relevant to reptiles that develop in subterranean nests with variable oxygen tensions. Previous work has shown hypoxia permanently alters the cardiovascular system of snapping turtles and may improve cardiac anoxia tolerance later in life. The mechanisms driving this process are unknown but may involve epigenetic regulation of gene expression via DNA methylation. To test this hypothesis, we assessed in situ cardiac performance during 2 h of acute anoxia in juvenile turtles previously exposed to normoxia (21% oxygen) or hypoxia (10% oxygen) during embryogenesis. Next, we analysed DNA methylation and gene expression patterns in turtles from the same cohorts using whole genome bisulfite sequencing, which represents the first high-resolution investigation of DNA methylation patterns in any reptilian species.ResultsGenome-wide correlations between CpG and CpG island methylation and gene expression patterns in the snapping turtle were consistent with patterns observed in mammals. As hypothesized, developmental hypoxia increased juvenile turtle cardiac anoxia tolerance and programmed DNA methylation and gene expression patterns. Programmed differences in expression of genes such as SCN5A may account for differences in heart rate, while genes such as TNNT2 and TPM3 may underlie differences in calcium sensitivity and contractility of cardiomyocytes and cardiac inotropy. Finally, we identified putative transcription factor-binding sites in promoters and in differentially methylated CpG islands that suggest a model linking programming of DNA methylation during embryogenesis to differential gene expression and cardiovascular physiology later in life. Binding sites for hypoxia inducible factors (HIF1A, ARNT, and EPAS1) and key transcription factors activated by MAPK and BMP signaling (RREB1 and SMAD4) are implicated.ConclusionsOur data strongly suggests that DNA methylation plays a conserved role in the regulation of gene expression in reptiles. We also show that embryonic hypoxia programs DNA methylation and gene expression patterns and that these changes are associated with enhanced cardiac anoxia tolerance later in life. Programming of cardiac anoxia tolerance has major ecological implications for snapping turtles, because these animals regularly exploit anoxic environments throughout their lifespan.

Diversity Patterns of Dung Beetles along a Mediterranean Elevational Gradient.

Simple SummaryMountains are ideal natural laboratories to study how biodiversity is influenced by environmental characteristics because climate varies rapidly from lowlands to high elevations. Scientists have investigated how the number of species varies with elevation for the most disparate plant and animal groups worldwide. However, species richness is only one aspect of biodiversity that does not consider species abundances. The so-called Hill numbers are a unified family of mathematical indices that express biodiversity in terms of both richness and abundance. We used Hill numbers to investigate how dung beetle diversity varies along an elevational gradient in a Mediterranean mountain. We found that scarabaeids were the most abundant dung beetle group. These insects construct subterranean nests protecting their offspring from desiccation during warm and dry summer climatic conditions. Additionally, in accordance with their preference for open habitats, we found that dung beetles are more abundant and diversified in grasslands than in woodlands. In the woodlands, diversity increased with elevation because of tree thinning, whereas in the grasslands, diversity decreased because of increasingly harsher environmental conditions. This indicates a trade-off in the beetle response to elevation between the positive effects of increasing the availability of suitable habitats and the worsening of environmental conditions.Most studies of biodiversity–elevational patterns do not take species abundance into consideration. Hill numbers are a unified family of indices that use species abundance and allow a complete characterization of species assemblages through diversity profiles. Studies on dung beetle responses to elevation were essentially based on species richness and produced inconsistent results because of the non-distinction between different habitats and the use of gradients dispersed over wide areas. We analyzed dung beetle diversity in a Mediterranean mountain (central Italy) for different habitats (woodlands vs. grasslands) and taxonomic groups (scarabaeids and aphodiids). Scarabaeids were the most abundant. Since scarabaeids are able to construct subterranean nests, this indicates that the warm and dry summer climatic conditions of high elevations favor species capable of protecting their larvae from desiccation. Dung beetles were more abundant and diversified in grasslands than in woodlands, which is consistent with their preference for open habitats. In the woodlands, diversity increased with increasing elevation because of increasing tree thinning, whereas, in the grasslands, diversity decreased with elevation because of increasingly harsher environmental conditions. These results indicate a trade-off in the beetle response to elevation between the positive effects of increasing the availability of more suitable habitats and the decrease of optimal environmental conditions.

The roles of diffusion and convection in ventilation of animal burrows.

The relationship between body mass and the respiratory microenvironment of burrowing animals is examined using artificial burrows containing surrogate animals that simulate O2 consumption by removal of air and simultaneous replacement with N2. Allometric relationships between body mass and burrow radius, nest chamber radius, and O2 consumption rate show that published mathematical predictions of diffusion-mediated gas exchange are adequate to describe the respiratory environments of animals in small blind-ending burrows through porous substrata. Diffusion is sufficient to ventilate burrows containing small mammals weighing less than 340g, or subterranean nest chambers connected to the surface by one or more tunnels containing mammals weighing less than 30kg. Outside of these limits, convection prevails and prevents the development of hypoxic conditions, particularly in burrows of mammals weighing more than 1300g.

The structure and importance of nest mounds in a tropical ant Diacamma indicum

1. Nest mounds are an integral part of many subterranean insect species, and they aid in thermoregulation, gaseous exchange, and flood prevention. Ants living in subterranean nests are prone to nest flooding particularly during monsoons and this will impact the colonies' fitness.2. Diacamma indicum is a tropical Ponerine ant species that lives in simple, single‐chambered nests with a single entrance. In this study, we characterised the mound architecture and performed field experiments to check functional significance of mounds.3. On examining mound architecture (n = 19 nests), we found that mounds not only elevated the nest entrance by 3.39 cm on average, but they also made the entrance at the top of the mound significantly smaller than the nest entrance at the base of the mound. Both these features are likely to reduce rainwater from falling directly into the nest's entrance tunnel.4. Upon performing partial (n = 18 nests) and complete destruction (n = 20 nests) in two different seasons, colonies were observed to actively rebuilt mounds to pre‐destruction levels within 3 days in all cases.5. Furthermore, examining the amount of water that entered the nest upon flooding in the presence and absence of mounds (n = 18 colonies) revealed that mounds prevented a minimum of 29.2% of water from seeping into the nest from the surrounding area, as mounds could act as a levee. This study highlights the active architectural adaptations to flooding by an organism that dwells in subterranean nests in a tropical habitat.