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The Dragonfly mission has the scope of studying the surface of Titan, Saturn's largest moon, using a rotorcraft lander. A mission-critical event in the timeline involves Dragonfly's initial flight as it descends into Titan's atmosphere. The preparation for this initial flight involves releasing the heat shield and utilizing the lander's rotors to damp motion while still attached to the parachute-supported aeroshell to ensure a smooth release. The aerodynamics of this event are studied in Titan conditions using high-fidelity computational fluid dynamics (CFD). The CFD model is benchmarked using available experimental measurements relevant to subcomponents of the event and include: (1) an open backshell, (2) bluff bodies similar to the Dragonfly fuselage, and (3) a rotor-body interaction from a helicopter rotor. The CFD results correlate well with measurements to provide confidence in the present studies focused on Titan. The novel studies presented in this work focus on the rotor-based control of the lander–backshell combination and its ability to mitigate spinning about the main parachute support line. This effort finds that the relatively large fuselage combined with near-fuselage rotors (driven by aeroshell space limitations) drives an unexpected aerodynamic interaction between the rotor and fuselage. Specifically, we observe low-pressure zones on the fuselage adjacent to the rotor that create a "suction" force. This first-order force creates an unexpected aerodynamic interaction that demands careful attention. In this paper, this force is documented and solutions are proposed to mitigate undesirable control character. • Aerodynamics of the Dragonfly lander interacting with a parachute-supported backshell. • Efforts supported using high-fidelity numerical models backed with a series of experimental benchmarks. • Elucidation of rotors inducing a strong force on the lander that need special consideration. • Proposed solutions highlighted by careful consideration of rotor orientation. [ABSTRACT FROM AUTHOR]

Orthetrum sabina is one of the most common dragonflies found in Nepal, but its feeding behavior has not often been reported from there. An example of this species preying on Neurothemis tullia is reported from Maidi Lake, Nepal. This observation was made during a field survey of Odonata using direct observation along transects around the lake. It adds to our knowledge of the species' feeding behavior, elaborating the previous findings and providing scope for further ecological studies on Odonata. [ABSTRACT FROM AUTHOR]

Deforestation in the tropics causes shifts in adult odonate community structure, from forests dominated by thermoconforming zygopteran specialists to open areas with higher representations of heliothermic anisopterans. We tested for these shifts in the Maquina and Cuecha rivers in Monteverde, Costa Rica. We compared adult odonate communities in 100 m plots (subdivided into twenty 5 m subplots) located in disturbed, partially open areas with those in 100 m plots located in intact forest and used general linear models to describe how odonate abundance, species richness, species diversity, and the Anisoptera/Zygoptera ratio varied among plots, subplots, habitat type (disturbed/forested), rivers, and as functions of percent canopy cover and light levels. Plots varied in light levels and percent canopy cover, but there were no significant differences in species richness or diversity. Community composition, however, varied across plots and subplots in NMDS and PERMANOVA analyses, largely as a consequence of the preference of Hetaerina cruentata and Paltothemis lineatipes for high light subplots and H. majuscula for low light subplots. NMDS axes were significantly correlated with percent canopy cover and light level in subplots, and the Anisoptera/Zygoptera ratio correlated with NMDS axes at both the plot and subplot scales, indicating that the relative abundance of anisopterans did increase with increasing light and decreasing canopy cover. Differences among plots and habitats can largely be attributed to species-specific differences in habitat selection at a small spatial scale, causing predicted shifts in the Anisoptera/Zygoptera ratio as dominance shifts from endemic forest species to wide-ranging generalists. This is one of the first studies that confirms these patterns for a cloud forest community. [ABSTRACT FROM AUTHOR]

Phylogenetic relationships of green-eyed skimmers, Macromia moorei was studied to estimate the evolutionary history among the members of family Corduliidae under order Odonata using the genetic methods of maximum probability, maximum parsimony, and Bayesian examination. Fifty-three DNA sequences and 3660 genetic characters/loci were used in the present study. Genetic distance of every nucleotide sequence was sorted from 0.69 to 98.10%. The outcomes of the combined COI + 16S DNA sequences revealed topology/phylogram through generally stronger bootstrap provision than evaluation of each gene in single analysis. Molecular analyses based on mitochondrial DNA yielded the position of M. moorei as a sister species of M.ampigena in family Corduliidae. [ABSTRACT FROM AUTHOR]

In floodplains, which are highly modified and less inundated, trees are expanding, thus raising concerns regarding their impact on freshwater organisms. We analyzed the relationship between forest expansion and the change in Odonata (dragonflies and damselflies) assemblage over an extended period of time in the floodplain with ponds of the Kiso River, central Japan. In the 1970s, the ponds were mainly surrounded by grasslands, and approximately 80% of Odonata species were non-forest species. However, the number of forest species increased and that of non-forest species largely decreased with the forest expansion over the past five decades, resulting in almost a similar number of forest and non-forest species in 2021. Whereas the abundance of the non-forest species had been greater than that of the forest species until the 2000s, the difference has been much smaller in the 2010s, and the non-forest species occupied approximately only 30% of the number of individuals in 2021. The forest expansion may have reduced the open-lentic habitats for the non-forest species, which require riparian grasslands for resting, foraging, and reproduction, and may disturb the immigration of non-forest species from the adjacent rice paddy fields and rivers. The development of canopy cover over the waterbodies may have decreased the light and temperature above and within the ponds, which might have caused a decline in species that prefer warm and open-water environments. Maintaining shifting-mosaic patterns of vegetation around the floodplain waterbodies through active management may be effective in conserving floodplain Odonata communities, including both forest and non-forest species. [ABSTRACT FROM AUTHOR]

In a two-year field study across 58 isolated wetlands in Texas (USA), we examined whether odonate (Insecta: Odonata) assemblages were structured by local environmental filters or instead simply reflected the use of any available water in this semi-arid region. Cluster analysis resolved three wetland groupings based on environmental characteristics (hydroperiod, water chemistry, vegetation); 37 odonate species were detected at these wetlands. The most speciose assemblages occurred at wetlands with longer hydroperiods; these sites also had the most species found at no other wetland type. Ordination plots indicated some filtering with respect to the hydroperiod, but there was only mixed or weak support with respect to other local factors. Because water persistence was the strongest driver maintaining odonate diversity in this region, regardless of water quality or vegetation, beggars cannot be choosers in this system and conservation efforts can focus on water maintenance or supplementation. [ABSTRACT FROM AUTHOR]

Understanding the distribution patterns of biodiversity is a pivotal challenge in ecology, exacerbated by the escalating frequency of anthropogenic events with severe consequences. This urgency underscores the need for comprehensive investigations, as exemplified by our study, which focuses on evaluating the effects of environmental and spatial variables on Odonata distribution across a gradient of vegetation cover in the eastern Amazonia landscape. In our investigation, we aimed to test the hypothesis that the distribution pattern of species in the suborder Zygoptera is significantly different from that of species in the suborder Anisoptera, considering that the environment is a more important factor for Zygoptera. Sampling was conducted across 27 streams within a landscape altered by various human activities, resulting in changes to riparian forests, sediment influx, and bank destabilization. Environmental alterations were quantified using the Habitat Integrity Index (HII) in conjunction with water's physical-chemical variables. We register 29 Odonata species/morphospecies, reflecting a significant biodiversity. Our hypothesis regarding the differing distribution patterns of species from the Odonata suborders Anisoptera and Zygoptera due to their ecophysiological distinctions was confirmed. This underscores that environmental and spatial factors serve as the primary determinants shaping the structure of Zygoptera suborder assemblages, given that the studied streams harbored environments that greatly impede the dispersal of species within this suborder. This study contributes valuable insights into the interplay between environmental changes induced by land use alterations and the resulting impacts on Odonata biodiversity in the Amazonian landscape. [ABSTRACT FROM AUTHOR]

Insects, despite possessing relatively small brains, exhibit noteworthy adaptive behaviors, making them intriguing subjects for understanding learning mechanisms. This study explores the learning capabilities of dragonfly larvae (Anisoptera: Aeshnidae) in conditioning experiments, shedding light on the cognitive processes that underpin their remarkable abilities. As apex predators, dragonflies play a crucial role in ecosystems, necessitating a diverse range of learning behaviors for survival and reproductive success. We addressed whether dragonfly larvae can differentiate between different colored stimuli and associate color with prey. Our experimental design demonstrated that dragonfly larvae are able to recognize conditioning stimuli. The findings contribute valuable insights into the cognitive abilities of dragonflies, suggesting that these insects can learn and discriminate colors of stimuli. Overall, this research broadens our understanding of insect learning and cognition, contributing to the broader field of animal behavior and memory. [ABSTRACT FROM AUTHOR]

Chironomid (Diptera: Chironomidae) larvae play a key role in aquatic food webs as prey for predators like amphibian and dragonfly larvae. This trophic link may be disrupted by anthropogenic stressors such as Bacillus thuringiensis var. israelensis (Bti), a biocide widely used in mosquito control. In a companion study, we recorded a 41% reduction of non-target larval chironomids abundance in outdoor floodplain pond mesocosms (FPMs) treated with Bti. Therefore, we examined the diet of two top predators in the FPMs, larvae of the palmate newt (Salamandridae: Lissotriton helveticus) and dragonfly (Aeshnidae: predominantly Anax imperator), using bulk stable isotope analyses of carbon and nitrogen. Additionally, we determined neutral lipid fatty acids in newt larvae to assess diet-related effects on their physiological condition. We did not find any effects of Bti on the diet proportions of newt larvae and no significant effects on the fatty acid content. We observed a trend in Aeshnidae larvae from Bti-FPMs consuming a higher proportion of large prey (Aeshnidae, newt, damselfly larvae; ~42%), and similar parts of smaller prey (chironomid, mayfly, Libellulidae, and zooplankton), compared to controls. Our findings may suggest bottom-up effects of Bti on aquatic predators but should be further evaluated, for instance, by using compound-specific stable isotope analyses of fatty acids or metabarcoding approaches. [ABSTRACT FROM AUTHOR]

Natural extracts, such as those from the residues of the Olea europaea industry, offer an opportunity for use due to their richness in antioxidant compounds. These compounds can be incorporated into porous polymeric devices with huge potential for tissue engineering such as bone, cardiovascular, osteogenesis, or neural applications using supercritical CO2. For this purpose, polymeric scaffolds of biodegradable poly(lactic-co-glycolic acid) (PLGA) and chitosan, generated in situ by foaming, were employed for the supercritical impregnation of ethanolic olive leaf extract (OLE). The influence of the presence of chitosan on porosity and interconnectivity in the scaffolds, both with and without impregnated extract, was studied. The scaffolds have been characterized by X-ray computed microtomography, scanning electron microscope, measurements of impregnated load, and antioxidant capacity. The expansion factor decreased as the chitosan content rose, which also occurred when OLE was used. Pore diameters varied, reducing from 0.19 mm in pure PLGA to 0.11 mm in the two experiments with the highest chitosan levels. The connectivity was analyzed, showing that in most instances, adding chitosan doubled the average number of connections, increasing it by a factor of 2.5. An experiment was also conducted to investigate the influence of key factors in the impregnation of the extract, such as pressure (10–30 MPa), temperature (308–328 K), and polymer ratio (1:1–9:1 PLGA/chitosan). Increased pressure facilitated increased OLE loading. The scaffolds were evaluated for antioxidant activity and demonstrated substantial oxidation inhibition (up to 82.5% under optimal conditions) and remarkable potential to combat oxidative stress-induced pathologies. [ABSTRACT FROM AUTHOR]

This paper explores the advantages of the Two Degree of Freedom Proportional-Integral-Derivative (2DOF_PID) controller in tracking the reference signal and rejecting the disturbance signal at the same time. Three types of metaheuristic optimization algorithms are employed for tuning the controller's parameters which are Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Dragonfly Algorithm (DA). These three algorithms have in common that they combine the exploratory concept (global search) and the exploitative concept (local search) in order to reach the optimal global solution. The effectiveness of these algorithms was taken advantage of to improve the performance of the control system that contains the controller. Second and third order plants were adopted for the purpose of testing, evaluating, and comparing the performance of the control system. This aim was accomplished by using each of the optimization algorithms for each plant. The simulation results showed the superiority of the DA in terms of obtaining the lowest value of the Integral Absolute Error (IAE) as the cost function. [ABSTRACT FROM AUTHOR]

In Japan, abandonment of rice fields has rapidly increased, resulting in biodiversity loss. Fallow field biotopes are attractive measures for compensating wetland species habitats in paddy environments. However, effective management practices of fallow field biotopes for biodiversity conservation are largely unknown, especially for lentic aquatic insects (Odonata, Hemiptera, and Coleoptera). We conducted field experiments in abandoned rice terraces in western Hyogo Prefecture, central Japan. We plowed and flooded nine abandoned paddy fields and divided them into three types: paddy fields, biotopes, and mixed fields. We also surveyed irrigation ponds. To assess the function of the four habitat types, we examined how species richness, abundance, and community composition of aquatic insects differed among habitat types. Aquatic insect assemblages in biotopes differed from paddy fields and ponds and resembled that in a mixed field. The effects of environmental factors on the abundance and species richness of aquatic insects differ according to their order or life stages. The abundance of aquatic insects increased with surface area. The abundance of Odonata nymphs increased with water depth, whereas that of Hemiptera nymphs and Coleoptera larvae decreased. The abundance of Odonata nymphs and Hemiptera adults increased with increasing vegetation cover, whereas the species richness of aquatic insects decreased. Thus, it is important to prevent high vegetation cover by plowing and create a water depth gradient for creating habitats for multiple taxa. We suggest that creating or maintaining mosaic habitats, including paddy fields, biotopes, and ponds could enhance aquatic insect diversity in abandoned rice terraces. [ABSTRACT FROM AUTHOR]

Abstract Aim This study aimed to analyze aspects of adult emergence of Phyllocycla Calvert, 1948 (Odonata: Gomphidae) in artificial environments. Samplings were conducted in Sanharó stream, Caxias municipality, Maranhão State, Brazil. Methods Specimens were examined under a stereomicroscope and identified to the lowest possible taxonomic level. Polystyrene boxes were used as rearing sites, and the following methods were analyzed: a) sand; b) strips of filter paper simulating substrate; c) without substrate. For emergence, the rearing sites had their lids removed and were placed inside larger jars with mesh windows, less water, with most of the substrate exposed above the water level. To verify the difference between treatments, the Log-rank test and Kaplan-Meier survival curves were used. Results The curves indicated that emergences occurred more frequently in the initial days of rearing. There was an absence of statistical difference between groups. Despite that, all treatments showed success in emergence, with larvae without substrate emerging more quickly. Conclusions By exploring the use of different substrates in Odonata rearing, this research provides guidelines for optimizing laboratory conditions, helping to overcome experimental challenges and supporting new studies and inventories.

The Cerrado harbors rich biodiversity and yet faces various anthropogenic pressures, an alarming situation that justifies fauna inventory studies, particularly insects, often overlooked in such endeavors. Additionally, many locations within the Cerrado lack information about the odonatofauna, including Conservation Units (CUs), considered the main tools for biodiversity conservation in Brazil. The objective of our study is to report the Odonata community occurring in the Minas Gerais portion of the Parque Nacional Grande Sertão Veredas (PNGSV), the conservation status of species, taxonomic information for some taxa, and compare the Odonata community along wet and dry seasons. The study was conducted from September 2022 to April 2023, with a total of 576 hours of sampling. We collected 601 specimens from 83 species, highlighting two new species (one recently described and other to be described elsewhere), eight new records for the state, and the rediscovery of the species Progomphus geijskesi Needham, 1944, collected for the first time in Brazil since 1918, and Argia botacudo Calvert, 1909, previously known only from the type material. The significant richness sampled, new taxa, new records, and the presence of species at some risk of extinction reinforce the Cerrado’s relevance as a global hotspot. It also underscores the importance of CUs as a tool to ensure the protection of Odonata communities in Brazil and highlights the need to strengthen public policies to guarantee investments and foster future financial resources for the protection of Brazilian biota, especially for conducting more inventory studies in the Cerrado.

For the first time, exuviae of Crocothemis sanguinolenta and Zygonyx torridus were collected from southern parts of Iran. Females of Z. torridus were also observed mating and ovipositing in two habitats. According to our data, these two species successfully breed in some suitable microhabitats and are neither immigrants nor vagrants. Our findings based on this research and recent information showed that habitat dispersal for these two species is not limited to the Hormuz Strait region, as previously thought. Suitable habitats for Z. torridus expanded from the Southwest to the East of the country. For C. sanguinolenta, the habitat range covers the far southeastern parts of the country near the Pakistan border area. Based on the geological history of the Persian Gulf region in the last glacial period and similar African coexisting species in these microhabitats, we suggest that these species are relict populations that survived in a few suitable habitats from a wider area in the past. This view seems more appropriate to explain the current distribution of these species than their recent migration from the UAE or Oman regions

Simple Summary: Climate warming has already changed the distribution and composition of European dragonflies, and this process is ongoing. One example is Trithemis annulata, which had been limited to southern Italy for over 150 years and which has expanded its range to the Po Plain in four decades. Recently, this species has established in some alpine valleys. We tracked the spread of this species by analysing all available data and modelled its preferred climatic conditions in Italy. Our results, which consider the years 1825–2023, indicate that Trithemis annulata has been moving northward since 1980 at a rate of approximately 12 km per year. Upon reaching the Po Plain in 2016, this rate increased to 34 km per year. Even though this species is known for its good dispersal ability, it was unable to keep up with the speed of the advancing climate. Trithemis annulata has expanded into new areas due to climate warming and is now established in Alpine valleys, which are potential gateways for the colonisation of central Europe. Climate warming has already influenced the distribution, community composition, and phenology of European Odonata. Trithemis annulata had been confined to the southern regions of Italy for over 150 years. In only four decades, it has expanded its range and has recently been observed inhabiting several alpine valleys. A dataset of 2557 geographical distribution data points spanning the years 1825–2023 was compiled using various resources, with the aim to analyse the chrono-story of the expansion of T. annulata. A further aim was to investigate the climatic conditions that best explain its current and future distribution. Over a period of 43 years, the species steadily extended its northern range margin at an approximate rate of 12 km/year. Once it reached the Po Plain, the expansion accelerated to an average speed of 34 km/year. However, its northward shift lagged behind the warming climate as we estimated an average speed of 28 km/year. In the future, the area suitable for T. annulata is expected to significantly increase in Italy. Surprisingly, we did not observe any consistent upward shift. Trithemis annulata has considerably expanded its distribution due to human-induced climate warming. The northernmost populations now inhabit Alpine valleys, potential gateways to central Europe. [ABSTRACT FROM AUTHOR]

In rivers, water temperature has a significant impact on aquatic organisms. Thermal infrared sensors mounted on unmanned aerial vehicles (UAVs), which can measure surface temperatures over an area with high spatial resolution, provide new ways to investigate river water temperatures. Therefore, we analyzed the high‐spatial‐resolution water temperature distribution acquired by UAV as an environmental factor affecting Calopteryx japonica inhabiting the river. The study site was a 9‐km section of the Sasayama River in the Kako River system, Japan. Adult and larval C. japonicas were counted walking along the water's edge. The water temperature distribution was determined by taking UAV photographs in August, when river temperatures were estimated to be the highest of the year, and in February, when river temperatures were estimated to be the lowest in the study area. The number of adult and larval C. japonicas were used as the objective variable, and water temperature, vegetation, and water area classification were used as variables in RandomForest analysis. These findings are consistent with existing research on C. japonica ecology. The analysis revealed that the water temperature distribution acquired by UAV can be used as an environmental factor in the analysis of aquatic organisms. This method has the potential to be applied to the analysis of other aquatic organisms. [ABSTRACT FROM AUTHOR]

Understanding species diversity and distribution cannot be overstated in the development of effective management and biological conservation strategies. Our goal was to address the knowledge gap regarding dragonfly diversity in the northeastern Atlantic Forest, specifically in the Serra of Itabaiana National Park in the state of Sergipe, Brazil. During our study, we recorded 40 species and 969 Odonata individuals across six families and 25 genera. This study contributes 27 new occurrence records of Odonata species in Sergipe, Brazil, highlighting the significance of preserving and protecting the habitats of this region. Our findings provide valuable information on the distribution of dragonfly species in the state of Sergipe and the Northeast region. [ABSTRACT FROM AUTHOR]

Odonata, a primitive group of amphibiotic insects, serves as vital indicators of habitat quality and ecosystem health due to their specific habitat preferences. Additionally, they contribute significantly to pest population control due to their predatory nature during both larval and adult stage. The genus, Camacinia, belonging to sub-family Libellulinae and family Libellulidae is known to comprise three species globally, Camacinia gigantea, Camacinia harterti and Camacinia othello. In India, C. harterti was first reported from Sikkim by Martin (Bull Mus Hist Nat 1900:103–108, 1900) and was enlisted in Indian Odonata fauna by Fraser (J Bombay Nat Hist Soc 27:253–269, 1920). However, the species was removed from Indian Odonata list and was not enlisted in majority of the recent literatures on Odonates of India. Here we report the recent sighting of Camacinia harterti, Karsch (Berl Entomol Z 33:347–392, 1890) from Namphing in Namchi District, Sikkim, India. There was no report of occurrence of C. harterti from Sikkim after Martin (Bull Mus Hist Nat 1900:103–108, 1900) record, and recent sighting of this species from Sikkim, India is a rediscovery of this species after a gap of 122 years. The implications of this rediscovery are significant, prompting thorough and extensive research on Odonates in the Himalaya. [ABSTRACT FROM AUTHOR]

This study presents a model experiment method that can accurately reproduce the flapping motion of insect wings and measure related unsteady aerodynamic data in real time. This method is applied to investigate the aerodynamic characteristics of inclined hovering, which distinguishes it from normal hovering by having asymmetric wing rotation during the two half strokes. In the study of the aerodynamic influence of the downstroke rotational angle, it is found that the rotational angle affects lift generation by changing the angle between the wing surface and the horizontal plane in the mid-downstroke. When the wing is almost parallel to the horizontal plane in the mid-downstroke, the vortex structure can maintain structural integrity and a large magnitude, which is conducive to the generation of high lift. In the study of the aerodynamic effect of the upstroke rotational angle, the windward conversion mechanism is proposed to explain the influence of the upstroke rotational angle on the direction and magnitude of thrust. Obtaining the rotational angle that is most conducive to maintaining the flight state of hovering in the present study can provide guidance for the structural design and kinematic control of micro aerial vehicles. [ABSTRACT FROM AUTHOR]

One of the drivers of life's diversification has been the emergence of "evolutionary innovations": The evolution of traits that grant access to underused ecological niches. Since ecological interactions can occur separately from mating, mating-related traits have not traditionally been considered factors in niche evolution. However, in order to persist in their environment, animals need to successfully mate just as much as they need to survive. Innovations that facilitate mating activity may therefore be an overlooked determinant of species' ecological limits. Here, we show that species' historical niches and responses to contemporary climate change are shaped by an innovation involved in mating--a waxy, ultra-violet-reflective pruinescence produced by male dragonflies. Physiological experiments in two species demonstrate that pruinescence reduces heating and water loss. Phylogenetic analyses show that pruinescence is gained after taxa begin adopting a thermohydrically stressful mating behavior. Further comparative analyses reveal that pruinose species are more likely to breed in exposed, open-canopy microhabitats. Biogeographic analyses uncover that pruinose species occupy warmer and drier regions in North America. Citizen-science observations of Pachydiplax longipennis suggest that the extent of pruinescence can be optimized to match the local conditions. Finally, temporal analyses indicate that pruinose species have been buffered against con-temporary climate change. Overall, these historical and contemporary patterns show that successful mating can shape species' niche limits in the same way as growth and survival. [ABSTRACT FROM AUTHOR]

Population dynamics, diversity and community structure of Odonata were studied on three adjacent riparian microecosystems in Vadodara district, Gujarat, India. Population dynamics was studied by observing their population by point count method on three microhabitats (Mini River at Sankarda, Sindhrot and Mahi River at Fazalpur). In the course of a twenty-eight-week study, a total of 4783 Odonata were encountered on three microecosystems. Odonata density 9% throughout September 2014 (39th Meteorological Week) and gained its peak during October 2014 (44th Meteorological Week). A definite drop in the density was observed during November 2014 (48th Meteorological Week) and it achieved precisely 1% throughout December 2014 (51st Meteorological Week). Amongst the three microecosystems, at Fazalpur, species richness began rising from the 4th week of September (6%) and made it to its highest (11%) throughout the 4th week of October. At Sankarda, maximum absolute richness (12.61%) was recorded in 3rd week of October. At Sindhrot, the relative abundance of odonates started increasing in 3rd week of September (7%) and achieved its highest (13%) during 4th week of October. A total of twenty-five species were encountered in the terrain. The diversity index was maximum for Sankarda (2.35) followed by Fazalpur (2.27) and Sindhrot (2.01). A total of four species (Ditch Jewel (26.6%), Pigmy Dartlet (19.5%), Green Marsh Hawk (10.3%) and Senegal Golden Dartlet (8.3%) were dominant in all three microhabitats. [ABSTRACT FROM AUTHOR]

This work details the development and validation of a methodology for high-resolution rotor models used in hybrid Blade Element Momentum Theory Unsteady Reynolds Averaged Navier–Stokes (BEMT-URANS) CFD. The methodology is shown to accurately predict single and coaxial rotor performance in a fraction of the time required by conventional CFD methods. The methodology has three key features: (1) a high-resolution BEMT rotor model enabling large reductions in grid size, (2) a discretized set of momentum sources to interface between the BEMT rotor model and the structured URANS flow solver, and (3) leveraging of the first two features to enable highly parallelized GPU-accelerated multirotor CFD simulations. The hybrid approach retains high-fidelity rotor inflow, wake propagation, and rotor–rotor interactional effects at a several orders of magnitude lower computational cost compared to conventional blade-resolved CFD while retaining high accuracy on steady rotor performance metrics. Rotor performance predictions of thrust and torque for both single and coaxial rotor configurations are compared to test the data that the authors obtained at the NASA Langley 14- by 22-ft. Subsonic Tunnel Facility. Simulations were run with both fully turbulent and free-transition airfoil performance tables to quantify the associated uncertainty. Single rotor thrust and torque were predicted on average within 4%. Coaxial thrust and power were predicted within an average of 5%. A vortex ring state (VRS) shielding phenomenon for coaxial rotor systems is also presented and discussed. The results support that this hybrid BEMT-URANS CFD methodology can be highly parallelized on GPU machines to obtain accurate rotor performance predictions across the full spectrum of possible UAM flight conditions in a fraction of the time required by conventional higher-fidelity methods. This strategy can be used to rapidly create look-up tables with hundreds to thousands of flight conditions using a three-dimensional multirotor CFD for UAM. [ABSTRACT FROM AUTHOR]

Titan is an ocean world with a dense atmosphere, where photochemistry produces complex organic molecules that fall to the surface. An important astrobiological question is whether this material can mix with water and form molecules of biological interest. Large impacts heat the moon's subsurface and create liquid water melt pools. A recent study investigated impacts into Titan's clathrate‐covered ice shell. Methane clathrates are stable at Titan's surface conditions and have low thermal conductivity, making them efficient insulators that can lead to steep thermal gradients and a thin stagnant lid. The authors showed that the clathrate layer thickness primarily influences the melt distribution, while its volume is governed by the impactor size. Here, we investigate the fate of melt formed during an impact into a clathrate‐covered ice shell. Our results show two different behaviors: in cases when less melt is produced, the subsurface melt pool remains close to the surface and freezes on timescales ≲25 kyr; in cases when larger volumes of melt are produced, a downward‐oriented transport of the molten material occurs. As it descends, part of the melt freezes but some may reach the ocean within a few kyr under certain conditions; vertical impacts, high surface porosity, low viscosity, and tidal heating all favor this surface‐to‐ocean exchange. While providing insights on parameters that allow a subsurface melt pool to remain liquid beneath a Selk‐sized crater for a few kyr, this study suggests that Dragonfly may be able to sample melt deposits where organics reacted with liquid water to produce biomolecules. Plain Language Summary: Titan, Saturn's largest moon, harbors a subsurface ocean beneath its ice shell. The moon also has an atmosphere, which is rich in large organic molecules that settle onto its surface. When atmospheric methane reacts with surface water ice, it forms methane clathrate. A clathrate layer atop Titan's ice shell affects the formation of Titan's impact craters, as it is both stronger than ice and a better insulator. Here, we study the effect of this clathrate layer on the formation and subsequent fate of melt pools produced by impacts on Titan. We investigate whether the melt descends through the ice shell to reach the ocean or remains near the surface and freezes. Our results show only a limited range of scenarios where impact melt reaches the ocean. In the majority of models, impact melt freezes near the surface within short timescales, ranging from a few thousands to tens of thousands of years. This implies that surface organic molecules may have interacted with subsurface melt pools. These results provide a positive outlook for NASA's Dragonfly mission, which will explore Titan's Selk crater in search of organic materials that have reacted with water to potentially form molecules of biological interest. Key Points: We studied the evolution of impact melt pools in Titan's ice shell using numerical simulations of two‐phase thermal convectionWhile most melt pools never reach the ocean, we observe surface‐to‐ocean exchange in a small part of the investigated parameter spaceOur results suggest that Dragonfly may be able to sample melt deposits where organics reacted with liquid water to produce biomolecules [ABSTRACT FROM AUTHOR]

The High Altitude Fields (HAF) are unique phytosociological features that occur only in certain regions of the Atlantic Forest. It is composed of herbaceous and shrubby vegetation and shallow soils that promote local water infiltration and recharge. Occurring on top of hills, the HAF are isolated units in the landscape, connecting with the matrix through associated ecosystems (springs with riparian forests and “capões de mata”, which are natural islands of arboreal vegetation, commonly associated with rural vegetation, such as high-altitude fields, located above 1,200 m in phytogeographic domains of the Atlantic Forest, Cerrado or Caatinga). These areas have great species endemism, and studies concerning the order Odonata are still scarce. Thus, we aimed to evaluate the ecological responses (richness, diversity, specificity) of adult odonates in these ecosystems. The study was conducted from November 2020 to March 2021 in three areas in the Poços de Caldas Plateau, Minas Gerais state, Brazil. A total of 45 species (247 specimens) were collected, with the highest total richness being recorded for Anisoptera. Among the sampled areas, there was no difference in Anisoptera communities, but there was a difference in Zygoptera species composition. In general, the most preserved remnant of HAF, the greater it presents greater richness of Odonata and harbors a regional pool of species.

The monotypic genus Epithemis Laidlaw, 1955, is endemic to the Western Ghats and is represented by the nominate species Epithemis mariae (Laidlaw, 1915). Epithemis mariae is distributed across the Western Ghats, and as part of an ongoing study, we identified a distinct population from Wayanad. Morphological and molecular data for E. mariae and the population from the Wayanad plateau affirm that the two are distinct taxa and allow us to describe a new species. Epithemis wayanadensis sp. nov. is described based on male specimens collected from Wayanad, a part of the Western Ghats in Kerala state, southern India.

Deforestation in the tropics causes shifts in adult odonate community structure, from forests dominated by thermoconforming zygopteran specialists to open areas with higher representations of heliothermic anisopterans. We tested for these shifts in the Maquina and Cuecha rivers in Monteverde, Costa Rica. We compared adult odonate communities in 100 m plots (subdivided into twenty 5 m subplots) located in disturbed, partially open areas with those in 100 m plots located in intact forest and used general linear models to describe how odonate abundance, species richness, species diversity, and the Anisoptera/Zygoptera ratio varied among plots, subplots, habitat type (disturbed/forested), rivers, and as functions of percent canopy cover and light levels. Plots varied in light levels and percent canopy cover, but there were no significant differences in species richness or diversity. Community composition, however, varied across plots and subplots in NMDS and PERMANOVA analyses, largely as a consequence of the preference of Hetaerina cruentata and Paltothemis lineatipes for high light subplots and H. majuscula for low light subplots. NMDS axes were significantly correlated with percent canopy cover and light level in subplots, and the Anisoptera/Zygoptera ratio correlated with NMDS axes at both the plot and subplot scales, indicating that the relative abundance of anisopterans did increase with increasing light and decreasing canopy cover. Differences among plots and habitats can largely be attributed to species-specific differences in habitat selection at a small spatial scale, causing predicted shifts in the Anisoptera/Zygoptera ratio as dominance shifts from endemic forest species to wide-ranging generalists. This is one of the first studies that confirms these patterns for a cloud forest community.

Simple Summary: Basic information on the ecology and behaviour of many aquatic insects is lacking because of the absence of studies. Here, we investigated whether demographic aspects such as survival, sex ratio, and population size are different between sexes and individuals of different ages of Teinopodagrion oscillans, a damselfly species endemic to the Andean region, living in a protected area. We also recorded the behaviour of this species and the area frequented by the adults near the water. Survival, recapture, and lifespan (14.1 ± 0.59 days) were similar for both sexes and all age groups. Mature males were larger, while the distance from the water where animals perched was similar for all individuals. Weather variations affected the demography of this population in a significant way. Individuals perch on any available support (≤0.1–12 m high) and show high fidelity to their perch site, with mature males making short flights from the perch to intercept other individuals and to hunt prey. The tandem position was formed on macrophytes, and females lay eggs by submersion of their abdomen. Our results provide crucial information for short- and long-term conservation decisions of the biodiversity in ecosystems of the Andean region. The demography and behaviour of Teinopodagrion oscillans was studied in a protected area in the Andean region of Colombia. Adult damselflies were individually marked, and using their recapture histories, we estimated survival, longevity, sex ratio, and population size using Cormack-Jolly-Seber models. Other aspects of their behaviour were recorded. Survival, recapture, and lifespan (14.1 ± 0.59 days) were similar for both sexes and all age groups. Mature males were larger, and the distance from the water was similar for all individuals. The most supported model was the time-dependent model for survival and recapture. This suggests that weather variations affect the demography of this population in a significant way. Individuals exhibited high fidelity to their site perch, perching with open wings near water on a variety of perches. Mature males make short flights from the perch to intercept conspecific and interspecific males and to hunt prey. The tandem position was formed on macrophytes, and then the pair flew away. Oviposition lasted for 11.23 min on average, with the females ovipositing by abdomen submersion. Our results offer insights into the demographic characteristics and behaviour of this species, providing crucial information for the short- and long-term, from the demography of one species to the conservation of ecosystems of the Andean region. [ABSTRACT FROM AUTHOR]

Urbanisation continues to increase at an alarming rate and its effects on the natural environment are very profound now more than ever. Moreover, studies on terrestrial urban landscapes seems to be more than that on urban freshwater habitats. Furthermore, studies have shown that the Odonata are effective indicators of the effects of urbanisation on freshwater habitats. However, not much is known about their responses to urbanisation in sub-Saharan Africa, especially given the unique set of conditions that characterise the area. Therefore, this study was conducted to investigate differences in Odonata responses, measured as the proportion of habitat generalists, to three levels of habitat disturbance in the Cape Coast Metropolis of Ghana. Results showed that Phaon camerunensis was a potential indicator of habitat disturbance. Also, differences in habitat disturbance significantly affected Odonata composition. The most important variables that influenced Odonata responses were the individual and interaction effects of altitude and preservation of riparian vegetation. Therefore, conservation strategies that are targeted at reducing the impacts of urbanisation on Odonata must focus on these variables. [ABSTRACT FROM AUTHOR]

An explorative study has been made on the dragonfly fauna of Babuzai, a tehsil in the tourist-attractive district of Swat, Pakistan. The study was conducted between April 2021 and June 2022, from 8:00 a.m. to 12:00 p.m. and 2:00 p.m. to 5:00 p.m. Collection was made from different areas of the study area, which are Odigram, Qambar, Rahim Abad, Gulkada, Islampur, Banr, Mingora, Kokarai, Tindodag, Manglawar, Bishbanh, Saidu Sharif, Marghuzar, Dangram, Jambil, and Sangar. A total of 18 species belonging to 2 families were documented. Libellulidae, with the highest percentage (94%), secured the richest among the familiesFamily Ashenidae was represented by a single species, accounting for 6% of the total documented species. Four species, Orthetrum iuzonicum, Sympetrum fonscolombii, Sympetrum commixtum, and Palpopleura sexmaculata, were reported for the first time for District Swat. The current study contributes to the existing knowledge base regarding the Odonata fauna of district Swat. The findings offer valuable implications for biodiversity management and ecosystem conservation efforts in the area. [ABSTRACT FROM AUTHOR]

For the first time, exuviae of Crocothemis sanguinolenta and Zygonyx torridus were collected from southern parts of Iran. Females of Z. torridus were also observed mating and ovipositing in two habitats. According to our data, these two species successfully breed in some suitable microhabitats and are neither immigrants nor vagrants. Our findings based on this research and recent information showed that habitat dispersal for these two species is not limited to the Hormuz Strait region, as previously thought. Suitable habitats for Z. torridus expanded from the Southwest to the East of the country. For C. sanguinolenta, the habitat range covers the far southeastern parts of the country near the Pakistan border area. Based on the geological history of the Persian Gulf region in the last glacial period and similar African coexisting species in these microhabitats, we suggest that these species are relict populations that survived in a few suitable habitats from a wider area in the past. This view seems more appropriate to explain the current distribution of these species than their recent migration from the UAE or Oman regions. [ABSTRACT FROM AUTHOR]

Traits and patterns of time allocation that improve mating success can impose costs with respect to other functions, including thermoregulation. In dragonflies, melanin on their wings can be used as a sexual signal. However, melanin also absorbs solar radiation and can cause animals to overheat in warm temperatures. We examined how dragonfly mating effort and thermoregulatory behaviour change in response to temperature and whether those responses vary based on levels of wing melanin ornamentation in the calico pennant dragonfly, Celithemis elisa. We conducted our study at the northern edge of C. elisa 's range and measured the time spent on mating effort behaviours and thermoregulatory behaviours as a function of ambient and microhabitat temperature in male dragonflies. We found a trade-off between mating effort and thermoregulatory behaviour in response to temperature; time spent on mating effort significantly decreased with increasing temperatures, while time spent on thermoregulation was positively related to temperature. However, we found no effect of wing melanin on behavioural patterns. These findings suggest that, as temperatures rise in response to climate change, some species may be forced to reduce important life history activities (including mating effort) with potential population level consequences for animals living in temperate areas. • Male dragonflies showed a trade-off between mating and thermoregulation. • Mating effort decreased with increasing temperature. • Thermoregulatory behaviour increased with temperature. • Our results suggest that climate change may reduce mating time for male dragonflies. [ABSTRACT FROM AUTHOR]

Prosthogonimiasis poses a threat to the reproductive system of poultry and wild birds, which are the definitive hosts of the parasite causing this disease. However, the parasite infection of the second intermediate host (dragonfly), the primary vector of this pathogen, is rarely reported. In this study, the prevalence of Prosthogonimus infection in dragonflies was investigated from June 2019 to October 2022 in Heilongjiang Province, northeast China. The species of metacercariae isolated from dragonfly were identified by morphological characteristics, molecular biology techniques, and animal infection experiments. The results showed that 11 species of dragonflies and one damselfly were identified and among six of the dragonflies infected by Prosthogonimus metacercariae, Sympetrum depressiusculum (28.53%) had the highest infection rate among all positive dragonflies, followed by Sympetrum vulgatum (27.86%) and Sympetrum frequens (20.99%), which are preferred hosts, and the total prevalence was 20.39% (2061/10,110) in Heilongjiang Province. Three species of Prosthogoniumus metacercariae were isolated, including Prosthogonimus cuneatus, Prosthogonimus pullucidus, and Prosthogonimus sp., among which P. cuneatus was the dominant species in dragonflies in Heilongjiang Province. This is the first report on the prevalence of Prosthogonimus in dragonflies in China, which provides baseline data for the control of prosthogonimiasis in Heilongjiang Province and a reference for the prevention of prosthogonimiasis in other areas of China. [ABSTRACT FROM AUTHOR]

The embryonic development of Pantala flavescens (Fabricius, 1798) is documented for the first time. In contrast to previously reported insect embryonic development, we describe the embryological development of P. flavescens in living conditions by focusing on its externally recognisable features, i.e., we conducted the study in a purely non-destructive manner. The entire embryonic development was completed within six to seven days. We pictured the eggs at successive embryonic developmental stages: embryogenesis starts, germband formation, segmentation, blastokinesis, appendage formation, and dorsal closure. These findings can be helpful in future studies regarding the impacts of pollutants and climate change on the early embryonic development of dragonflies. [ABSTRACT FROM AUTHOR]

A new technology that is gaining popularity today is the Wireless Sensor Network. Smart sensors are being used in a variety of wireless network applications, including intruder detection, transportation, the Internet of Things, smart cities, the military, industrial, agricultural, and health monitoring, as a result of their rapid expansion. Sensor network technologies improve social advancement and life quality while having little to no negative impact on the environment or natural resources of the planet are examined in sensor networks for sustainable development. Real-world applications face challenges ensuring Quality of Service (QoS) due to dynamic network topology changes, resource constraints, and heterogeneous traffic flow. By enhancing its properties, such as maintainability, packet error ratio, reliability, scalability, availability, latency, jitter, throughput, priority, periodicity, deadline, security, and packet loss ratio, the optimized QoS may be attained. Real-world high performance is difficult to attain since sensors are spread out in a hostile environment. The performance parameters are divided into four categories: network-specific, deployment phase, layered WSN architecture, and measurability. Integrity, secrecy, safety, and security are among the privacy and security levels. This article leads emphasis on the trustworthiness of the routes as well as the nodes involved in those routes from where the data has to pass from source to destination. First of all, the nodes are deployed and cluster head selection is done by considering the total number of nodes and the distance from the base station. The proposed work uses AODV architecture for computing QoS parameters that are throughput, PDR and delay. K-means clustering algorithm is used to divide the aggregated data into three possible segments viz. good, moderate and bad as this process does not involve the labelling of aggregated data due to its supervised behavior. The proposed trust model works in two phases. In first phase, data is divided into 3 segments and labelling is done. In second phase, uses generated class objects are to be applied viz. the route records to publicize the rank of the routes followed by the rank of nodes. The proposed technique employed the statistical machine learning and swarm intelligence strategy with dragon fly algorithm in order to address the issues related effective rank generation of nodes and improving the network lifetime. Deep learning concepts can be combined with fuzzy logics approach for resolving issues like secure data transmission, trustworthiness of ranking nodes and efficient route discovery.Article Highlights: This paper implies certain techniques for the lifetime enhancement of WSN. A modified version of dragonfly algorithm is used for achieving the trustworthiness of nodes and routes in the network. Trustnet is compared with existing techniques and it showed improvement in the results thereby attaining the trustworthiness of the network. [ABSTRACT FROM AUTHOR]

Abstract A new technology that is gaining popularity today is the Wireless Sensor Network. Smart sensors are being used in a variety of wireless network applications, including intruder detection, transportation, the Internet of Things, smart cities, the military, industrial, agricultural, and health monitoring, as a result of their rapid expansion. Sensor network technologies improve social advancement and life quality while having little to no negative impact on the environment or natural resources of the planet are examined in sensor networks for sustainable development. Real-world applications face challenges ensuring Quality of Service (QoS) due to dynamic network topology changes, resource constraints, and heterogeneous traffic flow. By enhancing its properties, such as maintainability, packet error ratio, reliability, scalability, availability, latency, jitter, throughput, priority, periodicity, deadline, security, and packet loss ratio, the optimized QoS may be attained. Real-world high performance is difficult to attain since sensors are spread out in a hostile environment. The performance parameters are divided into four categories: network-specific, deployment phase, layered WSN architecture, and measurability. Integrity, secrecy, safety, and security are among the privacy and security levels. This article leads emphasis on the trustworthiness of the routes as well as the nodes involved in those routes from where the data has to pass from source to destination. First of all, the nodes are deployed and cluster head selection is done by considering the total number of nodes and the distance from the base station. The proposed work uses AODV architecture for computing QoS parameters that are throughput, PDR and delay. K-means clustering algorithm is used to divide the aggregated data into three possible segments viz. good, moderate and bad as this process does not involve the labelling of aggregated data due to its supervised behavior. The proposed trust model works in two phases. In first phase, data is divided into 3 segments and labelling is done. In second phase, uses generated class objects are to be applied viz. the route records to publicize the rank of the routes followed by the rank of nodes. The proposed technique employed the statistical machine learning and swarm intelligence strategy with dragon fly algorithm in order to address the issues related effective rank generation of nodes and improving the network lifetime. Deep learning concepts can be combined with fuzzy logics approach for resolving issues like secure data transmission, trustworthiness of ranking nodes and efficient route discovery.

In a two-year field study across 58 isolated wetlands in Texas (USA), we examined whether odonate (Insecta: Odonata) assemblages were structured by local environmental filters or instead simply reflected the use of any available water in this semi-arid region. Cluster analysis resolved three wetland groupings based on environmental characteristics (hydroperiod, water chemistry, vegetation); 37 odonate species were detected at these wetlands. The most speciose assemblages occurred at wetlands with longer hydroperiods; these sites also had the most species found at no other wetland type. Ordination plots indicated some filtering with respect to the hydroperiod, but there was only mixed or weak support with respect to other local factors. Because water persistence was the strongest driver maintaining odonate diversity in this region, regardless of water quality or vegetation, beggars cannot be choosers in this system and conservation efforts can focus on water maintenance or supplementation.

Abstract Background Migratory insects are important for the provision of ecosystem services both at the origin and destination sites but – apart from some iconic species – the migration routes of many insect species have not been assessed. Coastlines serve as a funnel where migrating animals including insects accumulate. Migratory behaviour and captures of dragonflies in bird traps suggest autumn migration of dragonflies along coastlines while the origin and regularity of this migration remain unclear. Methods Dragonfly species were caught at the bird observatory Kabli at the Baltic coast in Estonia in 2009, 2010 and 2015. For the 2015 data set, we used a stable hydrogen (H) approach to trace the potential natal origin of the migrant hawker (Aeshna mixta). Results 1079 (2009), 701 (2010) and 88 (2015) A. mixta individuals were caught during the study periods (35, 37 and 11 days in 2009, 2010 and 2015, respectively). The migration period lasted from end of August to end of September. Based on the results from our stable isotope analysis, we identified two populations of A. mixta: One (range of isotope signatures of non-exchangeable H [δ2Hn wing]: −78‰ to −112‰) had a local likely origin while the other (δ2Hn wing: −113‰ to −147‰) migrated from northerly directions even in headwind from the South. The former showed an even sex ratio whereas the actively migrating population was dominated by males. Conclusions Our results suggest a regular southbound autumn migration of A. mixta along the Baltic coast. However, nearly half of the sampled individuals originated from the surroundings suggesting either no, partial or “leap-frog” migration. Contrary to our expectation, A. mixta did not select favourable wind conditions but continued the southbound autumn migration in the flight boundary layer even in case of headwinds. The dominance of males might indicate migration as a result of competition for resources. Further repeated, large-scale studies along the Baltic coast are necessary to pinpoint the migratory pattern and the reason for migration of A. mixta. Such studies should also comprise locations north of the known species range of A. mixta because of the rapid climate-change induced range expansion.

This study presents an integrated dataset comprising occurrence records for 102 Odonata species in South Korea. The occurrence information of the Odonata species was collected from 10 independent field survey-based datasets, spanning the period from 2014 to 2023 and provided by three agencies: National Institute of Ecology, National Institute of Environmental Research, and Global Biodiversity Information Facility (GBIF). In addition to occurrence data, the dataset includes information on the survey year, IUCN (International Union for Conservation of Nature) Red List classification, satellite-derived spectral indices and bioclimatic variables to provide valuable insights into the survey sites and habitats of Odonata species. By integrating diverse dataset, this comprehensive Odonata dataset can contribute to the validation of habitat-related traits, enhances the national checklist information, and facilitates the identification of rarity and potential habitats for Odonata species in South Korea. The integrated Odonata dataset serves as a valuable resource for ongoing Odonata research and conservation efforts in the study area.

Little is known about odonate ecology and phenology in warm mediterranean climates where most wetlands are intermittent. We identified variables associated with the presence, relative abundance, assemblage composition and body size of odonates in spring and summer, to understand the influence of intermittency and season. We hypothesized that size at eclosion would be smaller in seasonal wetlands in summer due to time stress caused by drying. Nymphs, exuviae and adults were sampled in spring and summer from 22 intermittent and perennial suburban wetlands in south‐western Australia. Spatial and environmental variables within and between wetlands were measured and associated with adult and nymph distributions. Exuviae were collected to quantify size at eclosion. As in temperate perennial wetlands, wetland‐scale variables (submerged, emergent and terrestrial vegetation, water temperature) were most strongly associated with assemblage composition of adults and nymphs, but landscape‐scale variables (distance to nearest patch of native vegetation, distance to nearest large lake) were also associated with adult assemblages. Two abundant dragonfly (Orthetrum caledonicum Libellulidae, Hemicordulia tau Hemicorduliidae) and one damselfly (Xanthagrion erythroneurum Coenagrionidae) species emerged at smaller body sizes in summer than spring, but from both intermittent and perennial wetlands. Consequently, declining photoperiod and warmer summer temperatures, rather than wetland drying, probably caused reduced size at eclosion. Although the influence of vegetation, temperature and photoperiod on odonate assemblages appears similar in temperate and mediterranean climates, odonate phenology differs markedly. Fitness cost of emerging at a smaller adult size may be outweighed by the increased likelihood of successfully reaching emergence in drying waterbodies in summer. More field data on size at eclosion in warm climate regions, and laboratory experiments manipulating temperature and photoperiod, are needed to confirm the generality of patterns shown here. [ABSTRACT FROM AUTHOR]

Springs are environments that can provide general insights into factors favouring diversity in ecotones, but they are often neglected in freshwater studies. One of the challenging processes acting in ecotones is the landscape of fear (LOF), the space–time variation of perceived predation risk. Spring exploitation often involves species that are mesopredators in surface fresh water and that can become apex predators in ground water, as in the case of the fire salamander larvae (Salamandra salamandra). Here, we aim to determine whether the activity and foraging patterns of the fire salamander in springs are affected by LOF.We surveyed the night‐ and daytime abundance of fire salamander larvae in 15 springs to assess predator occurrence. We also reared 48 salamander larvae with and without non‐lethal exposure to predators within tanks simulating groundwater or surface freshwater light features. Before and after a month of rearing, we tested larva efficiency in catching prey when exposed to predator chemical cues, both in light and dark conditions.In the field, the number of active fire salamander larvae was significantly higher during the night. At night, the number of active larvae across the transition area between ground water and surface water was higher in plots closer to the surface.Testing and rearing conditions significantly affected larva behaviour, and prey capture was significantly more effective in light conditions. It was less successful in larvae reared with predator chemical cues and in the presence of predators. Moreover, larvae reared with predators under light conditions were slower than those raised with predators in dark conditions.Our results show that LOF can interact with extant environmental features and constitute a significant behavioural pressure for mesopredator species living in freshwater ecotones. [ABSTRACT FROM AUTHOR]

The regionally threatened damselfly Sympecma peadisca is one of the few Central European dragonfly species included is considered as Near Threatened in the European Red list. The major threats to this species remain unclear. This species has a unique life history and several adaptations to enabling survival even in semidesert areas, such as overwintering in the adult stage. However, the closely related, more thermophilic species Sympecma fusca has undergone a major range expansion in Europe. Based on data from 129 sites and combining several analytical approaches, I found the following: 1. According to local freshwater conditions, S. paedisca is a typical habitat generalist occupying a wide range of habitats. 2. It requires a wide range of terrestrial habitats to complete its life cycle. 3. An analysis of the land used by both species clearly indicates that both species avoid intensive agricultural areas; however, S. fusca can also occur in suburban areas, where S. paedisca is absent. 4. Projections of the Least Cost Path analysis indicate that the only localities where the species is currently spreading are habitats arising as a consequence of mining activities. The example of S. paedisca is clear evidence of a freshwater species that responds very negatively to the homogenization of the terrestrial environment, even when its natal habitat is not significantly affected. The frequent occurrence of species in postmining areas suggests that species with complex habitat requirements can find suitable secondary habitats where they can prosper in the long term. Implications for insect conservation: Even semi-aquatic groups like damselflies can be very sensitive to gradual changes in surrounding land use. Species with very complex habitat requirements also require comprehensive conservation strategies affecting all habitats utilized by the species. However, the return of some landscape features requires a reduction in the area of production areas in favor of hedgerows and ruderals. Such restoration management requires long-term planning and close cooperation with farmers. [ABSTRACT FROM AUTHOR]

Small lowland watercourses, strongly exposed to anthropogenic activities and climate change, have received negligible odonatological attention. This study provides a revised checklist of three typical lowland small watercourses (Kállai-főfolyás, Konyári-Kálló and Ölyvös) within the Pannonian Lowland and presents the changes in their diversity over the past decades. Results revealed a significant biodiversity loss, with a 31.6% decline in Odonata fauna over the last 53 years. The upper and middle sections degraded the most, where the habitats have dried out or become intermittent. However, a diverse Odonata assemblage (1,277 individuals of 27 species) was observed at the 14 sampling sites of the three watercourses, containing protected and sensitive species (Somatochlora flavomaculata, Orthetrum brunneum, Aeshna isoceles, Libellula fulva). However, the low abundance of larval and exuvial forms (59 individuals of 13 species) suggests that the majority of the observed adults were developed in other watercourses. While recolonisation from nearby habitats is still possible, a parallel degradation of adjecent waterbodies could lead to an irreversible biodiversity loss. [ABSTRACT FROM AUTHOR]

We characterized dragonfly wings from three species, Sympetrum frequens, Orthetrum albistylum speciosum, and Sympetrum infuscatum, collected in Chitose City using Fourier transform infrared (FTIR) imaging and infrared (IR) dichroism imaging. In the FTIR images, the distribution of amide I and II bands derived from the chitin was observed across the entire vein domain; however, strong absorption for the amide bands was observed in the thicker vein domain membrane: approximately 23% of the total vein domain membrane in the wing. IR dichroism images indicated that the chitin in the thinner vein domain membrane was oriented along the primary vein. [ABSTRACT FROM AUTHOR]

Simple Summary: Two species of Sympetrum, namely S. depressiusculum and S. frequens, have been documented in South Korea. However, the distinction between these two species and their identity within South Korean populations has been a longstanding point of contention. To solve this issue, morphology, two mitochondrial genes, and one nuclear region were analyzed for S. depressiusculum samples from The Netherlands and Russia and S. frequens samples from Japan, as well as samples of Sympetrum from South Korea. Further, available public sequence data for the two species were included. Morphology, sequence divergence, and phylogenetic results all consistently suggest that South Korean populations form a single species. Analyses of haplotype network and gene pool distribution patterns in a nuclear region conducted to better explain the current taxonomic implications indicated changes in the dominant gene pool from The Netherlands and Russia to South Korea and Japan. However, such divergence and subdivision could be explained within the context of within-species diversification patterns, suggesting that South Korean populations constitute one species, S. depressiusculum, by applying the senior name. In South Korea, both Sympetrum depressiusculum Sélys, 1841 (Odonata: Libellulidae), which is distributed throughout Europe and from Russia to the Korean Peninsula, and Sympetrum frequens Sélys, 1883, which is endemic to Japan, are recorded. However, the identity of South Korean populations and the validity of listing the two species have not yet been settled. In this study, we collected seventy-four individuals of Sympetrum species from South Korea (five localities), Russia, The Netherlands, and Japan. These samples were examined for morphology and sequenced for partial COI, 16S rRNA, and a nuclear internal spacer (ITS) region, after which these molecular data were combined with available public data from Russia, Japan, and The Netherlands. Major morphological characters that have been used to distinguish the two species and phylogenetic, network, and structure analyses all consistently suggest that South Korean populations form a single species. Consequently, it could be valid to treat South Korean populations as one species, S. depressiusculum, by applying the senior name. Nevertheless, the validity of maintaining each as an independent species in other countries may need additional study considering that our samples were focused more on South Korea and limited for Europe, Russia, and Japan. [ABSTRACT FROM AUTHOR]

Natural extracts, such as those from the residues of the Olea europaea industry, offer an opportunity for use due to their richness in antioxidant compounds. These compounds can be incorporated into porous polymeric devices with huge potential for tissue engineering such as bone, cardiovascular, osteogenesis, or neural applications using supercritical CO2. For this purpose, polymeric scaffolds of biodegradable poly(lactic-co-glycolic acid) (PLGA) and chitosan, generated in situ by foaming, were employed for the supercritical impregnation of ethanolic olive leaf extract (OLE). The influence of the presence of chitosan on porosity and interconnectivity in the scaffolds, both with and without impregnated extract, was studied. The scaffolds have been characterized by X-ray computed microtomography, scanning electron microscope, measurements of impregnated load, and antioxidant capacity. The expansion factor decreased as the chitosan content rose, which also occurred when OLE was used. Pore diameters varied, reducing from 0.19 mm in pure PLGA to 0.11 mm in the two experiments with the highest chitosan levels. The connectivity was analyzed, showing that in most instances, adding chitosan doubled the average number of connections, increasing it by a factor of 2.5. An experiment was also conducted to investigate the influence of key factors in the impregnation of the extract, such as pressure (10–30 MPa), temperature (308–328 K), and polymer ratio (1:1–9:1 PLGA/chitosan). Increased pressure facilitated increased OLE loading. The scaffolds were evaluated for antioxidant activity and demonstrated substantial oxidation inhibition (up to 82.5% under optimal conditions) and remarkable potential to combat oxidative stress-induced pathologies.