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Mammalian hearing operates on three basic steps: 1) sound capturing, 2) impedance conversion, and 3) frequency analysis. While these canonical steps are vital for acoustic communication and survival in mammals, they are not unique to them. An equivalent mechanism has been described for katydids (Insecta), and it is unique to this group among invertebrates. The katydid inner ear resembles an uncoiled cochlea, and has a length less than 1 mm. Their inner ears contain a hearing organ, crista acustica, which holds tonotopically arranged sensory cells for frequency mapping via travelling waves. The crista acustica is located on a curved triangular surface formed by the dorsal wall of the ear canal. While empirical recordings show tonotopic vibrations in the katydid inner ear for frequency analysis, the biophysical mechanism leading to tonotopy remains elusive due to the small size and complexity of the hearing organ. In this study, robust numerical simulations are developed for an in silico investigation of this process. Simulations are based on the precise katydid inner ear geometry obtained by synchrotron-based micro-computed tomography, and empirically determined inner ear fluid properties for an accurate representation of the underlying mechanism. We demonstrate that the triangular structure below the hearing organ drives the tonotopy and travelling waves in the inner ear, and thus has an equivalent role to the mammalian basilar membrane. This reveals a stronger analogy between the inner ear basic mechanical networks of two organisms with ancient evolutionary differences and independent phylogenetic histories. Author summary: Katydids (Insecta) have a unique hearing system among invertebrates because, similar to mammals, they exhibit outer, middle, and inner ear components. The katydid inner ear resembles an uncoiled mammalian cochlea. Although much smaller in size (∼700 μm), the katydid inner ear possesses a tonotopic frequency-discriminating sensory epithelium like the mammalian cochlea. Yet, the mechanical equivalence between the workings of the two inner ears has not been investigated experimentally, due to the minuscule dimension and tightly integrated inner ear components of the katydid ear. In this study, comprehensive numerical simulations are developed using accurate 3D ear models to investigate such an equivalence. The results reveal that similar to the mammalian basilar membrane, the triangular structure holding the katydid hearing organ drives the movements of the mechanosensors, so that the minuscule katydid inner ear functions with a similar biophysical mechanism as the mammalian cochlea. This provides a unique opportunity to infer processes difficult to measure in the mammalian cochlea through an analogous model auditory system. [ABSTRACT FROM AUTHOR]

Background: In evolutionary biology, identifying and quantifying inter-lineage genome size variation and elucidating the underlying causes of that variation have long been goals. Repetitive elements (REs) have been proposed and confirmed as being among the most important contributors to genome size variation. However, the evolutionary implications of genome size variation and RE dynamics are not well understood. Results: A total of 35 Ensifera insects were collected from different areas in China, including nine species of crickets and 26 species of katydids. The genome sizes of seven species were then determined using flow cytometry. The RepeatExplorer2 pipeline was employed to retrieve the repeated sequences for each species, based on low-coverage (0.1 X) high-throughput Illumina unassembled short reads. The genome sizes of the 35 Ensifera insects exhibited a considerable degree of variation, ranging from 1.00 to 18.34 pg. This variation was more than 18-fold. Similarly, the RE abundances exhibited considerable variation, ranging from 13.66 to 61.16%. In addition, the Tettigonioidea had larger genomes and contained significantly more REs than did the Grylloidea genomes. Analysis of the correlation between RE abundance and the genome size of 35 Ensifera insects revealed that the abundance of REs, transposable elements (TEs), long terminal repeats (LTRs), and long interspersed nuclear elements (LINEs) are significantly correlated with genome size. Notably, there is an inflection point in this correlation, where species with increasingly large genomes (e.g., > 5–10 pg) have repeats that contribute less to genome expansion than expected. Furthermore, this study revealed contrasting evolutionary directions between the Tettigonioidea and Grylloidea clades in terms of the expansion of REs. Tettigonioidea species exhibit a gradual increase in ancestral genome size and RE abundance as they diverge, while Grylloidea species experience sustained genome contraction. Conclusions: This study reveals extensive variation in genome size and RE abundance in Ensifera insects, with distinct evolutionary patterns across two major groups, Tettigonioidea and Grylloidea. This provides valuable insights into the variation in genome size and RE abundance in Ensifera insects, offering a comprehensive understanding of their evolutionary history. [ABSTRACT FROM AUTHOR]

Orthoptera species are vulnerable to extinction on a global scale. Greece hosts 35% (380 species) of the European Orthoptera fauna with a high degree of endemic (37%) and threatened species (37%). We sampled 46 plots (100 m2) to investigate the distribution and ecological requirement of two Greek mountain endemic and red‐listed species: Parnassiana parnassica (Ramme, 1926; Orthoptera: Tettigoniidae; Critically Endangered [CR]) and Oropodisma parnassica (Scudder, 1897; Orthoptera: Caelifera; Endangered [EN]). Species had a restricted geographical range, with two isolated populations confined to high altitudes (1527–2320 m) of Mts. Parnassos and Elikonas. Species distribution models showed that slope affected their suitable habitat, together with the topographic position index and the annual temperature range (P. parnassica), and the amount of green vegetation and evapotranspiration (O. parnassica). Connectivity analysis showed that P. parnassica‐suitable habitat consisted of few larger and well‐connected patches (26 patches: effective mesh size of 1.57 km2) and that O. parnassica‐suitable habitat consisted of more but smaller and less connected patches (56 patches: effective mesh size of 0.3 km2). Generalised linear models showed that the population density of P. parnassica was negatively influenced by the height of herbaceous vegetation and that of O. parnassica was positively influenced by altitude. The species face three main imminent threats: land take, wildfires and global warming, whereas livestock grazing seems to have a positive impact and skiing a neutral impact on their populations. We assessed both species as EN after International Union for Conservation of Nature (IUCN) criteria and a suite of conservation measures are suggested for their status improvement. [ABSTRACT FROM AUTHOR]

Tarbinskiellus portentosus (Lichtenstein, 1796) (bush cricket), also called "viituo" in the Angami dialect, belongs to the order Orthoptera and the family Gryllidae. It is one of the most common edible insects found in Nagaland and is a potential source of animal protein and other nutrients. Despite being highly preferred as food and relished, studying their ecology, biology, and market potential is nonexistent, at least in Nagaland, India. Therefore, the present study was conducted to fill the knowledge gap on the biology and market potential of T. portentosus. Insects were collected from the wild and reared as stock at 20-25 °C. The results show that T. portentosus undergoes seven nymphal instars to fully develop into an adult with an average growth rate of 9.94 ± 2.43 mg/day. T. portentosus is found in the grassland vegetation in burrows up to 800 mm depth. Adult males weigh about 2940 ± 93.0 mg, and females weigh 2980 ± 200 mg. The incubation period of eggs was 33.8 ± 0.96 days and showed a moderate percent of hatching efficiency (45.20 ± 0.28). In laboratory conditions, this cricket completed its life cycle in 341 ± 4.29 days. Collection of adults involves handpicking and pouring water, cleaning involves a gut removal process through head pulling, and preparation for consumption is done by cooking with local spices, fried or roasted. T. portentosus are sold in the local market at INR 300/- for 250-300 g. With scanty information on growth and reproduction, the present study serves as a baseline for future studies on the biology of T. portentosus that may uplift the local market through mass rearing. [ABSTRACT FROM AUTHOR]

Herein, we describe the genus Dentotibium gen. nov. and the species D. ramucantoris sp. nov , a toothed foretibia katydid within the subfamily Pseudophyllinae from Colombia. This new katydid is a forest dweller inhabiting oak woodlands between 1600 and 2300 m above sea level, only found in the western slopes of the Eastern Andes of Boyacá Department, Colombia. This new species burrows in woody branches and shows big heads in both sexes. The appearance of Dentotibium gen. nov. is similar to that of Trichotettix Stål, 1873 but differs in having tubercles over the dorsal margin of the foretibiae. It is also close to Nastonotus Bolívar, 1890, but differs from in lacking the three black stripes in the vertex and having a less marked frontal suture and smoother face. Males sing all night long, and their calling song consists of periodic syllables with three differentiable phases. Seasonal calling activity lowers remarkably during the dry season (Jun–Aug). DNA barcoding sequences for the paratypes made available in a previous study are included here. [ABSTRACT FROM AUTHOR]

This study investigates the variations in body size, bioacoustic traits, and cuticular hydrocarbon (CHC) profiles in different populations of the bush cricket species Isophya autumnalis Karabağ, 1962. Within-population body size variations, particularly those associated with distinct habitat differences and climate shifts within their local distribution ranges, suggest that ecological factors affect morphological characteristics. Sexual size dimorphism (SSD) in I. autumnalis may affect reproductive behavior and strategies, potentially influenced by the bioacoustic environment. While male calling songs exhibit temporal variations across populations, suggesting differences among allopatric populations, CHC profiles, known to undergo selection under various climatic conditions, also vary noticeably across local populations. These findings highlight the importance of understanding within-species variations for the conservation of Isophya and similar taxa in the face of habitat threats. Overall, this study contributes to a comprehensive understanding of how morphology and bioacoustic behavioral traits are shaped over short distances in allopatric populations of species with limited mobility, such as I. autumnalis, providing insights into adaptation processes and highlighting the urgency of conservation efforts for endemic species in Anatolia. [ABSTRACT FROM AUTHOR]

Animals often signal in multiple sensory modalities to attract mates, but the level of signaling investment in each modality can differ dramatically between individuals and across species. When functionally overlapping signals are produced in different modalities, their relative use can be influenced by many factors, including differences in signal active space, energetic costs, and predation risk. Characterizing differences in total signal investment across time can shed light on these factors, but requires long focal recordings of signal production. Neotropical pseudophylline katydids produce mate advertisement signals as airborne sound and substrate-borne vibration. Airborne calls, produced via stridulation, are extremely short, high-frequency, and longer-range signals. Conversely, substrate-borne calls produced via abdominal tremulation are longer, low-frequency, relatively more energetically costly, and shorter-range signals. To examine patterns of stridulation and tremulation across species and test hypotheses about the drivers of signal use in each modality, we recorded multimodal signaling activity over 24 hours for males from 10 pseudophylline species from a single Panamanian community. We also collected data on demographic and morphological species characteristics, and acoustic features of airborne calls, such as bandwidth, peak frequency, and duration. Finally, we generated a molecular phylogeny for these species and used phylogenetic generalized least squares models to test for relationships between variables while controlling for evolutionary relationships. We found a negative relationship between sound and vibration calling, indicating that substrate-borne vibrational signaling may compensate for reduced airborne signaling in these species. Sound call bandwidth and the proportion of males collected at lights, a proxy for the amount of male movement, also explained a significant amount of variation in sound calling across species, indicating that the overall relationship between the two types of calling signals may be mediated by the specific characteristics of the signals as well as other species traits. [ABSTRACT FROM AUTHOR]

The order Orthoptera includes insects such as grasshoppers, katydids, and crickets, among which there are important species for ecosystem stability and pollination, as well as research organisms in different fields such as neurobiology, ecology, and evolution. Crickets, with more than 2,400 described species, are emerging as novel model research organisms, for their diversity, worldwide distribution, regeneration capacity, and their characteristic acoustic communication. Here we report the assembly and annotation of the first New World cricket, that of Gryllus longicercus Weissman & Gray 2019. The genome assembly, generated by combining 44.54 Gb of long reads from PacBio and 120.44 Gb of short Illumina reads, has a length of 1.85 Gb. The genome annotation yielded 19,715 transcripts from 14,789 gene models. [ABSTRACT FROM AUTHOR]

Insects are the most diverse animal taxon on Earth and play a key role in ecosystem functioning. However, they are often neglected by ecological surveys owing to the difficulties involved in monitoring this small and hyper-diverse taxon. With technological advances in biomonitoring and analytical methods, these shortcomings may finally be addressed. Here, we performed passive acoustic monitoring at 141 sites (eight habitats) to investigate insect acoustic activity in the Viruá National Park, Brazil. We first describe the frequency range occupied by three soniferous insect groups (cicadas, crickets and katydids) to calculate the acoustic evenness index (AEI). Then, we assess how AEI varies spatially and temporally among habitat types, and finally we investigate the relationship between vegetation structure variables and AEI for each insect category. Overall, crickets occupied lower and narrower frequency bands than cicadas and katydids. AEI values varied among insect categories and across space and time. The highest acoustic activity occurred before sunrise and the lowest acoustic activity was recorded in pastures. Canopy cover was positively associated with cricket acoustic activity but not with katydids. Our findings contribute to a better understanding of the role of time, habitat and vegetation structure in shaping insect activity within diverse Amazonian ecosystems. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'. [ABSTRACT FROM AUTHOR]

Night-time light can have profound ecological effects, even when the source is natural moonlight. The impacts of light can, however, vary substantially by taxon, habitat and geographical region. We used a custom machine learning model built with the Python package Koogu to investigate the in situ effects of moonlight on the calling activity of neotropical forest katydids over multiple years. We prioritised species with calls that were commonly detected in human annotated data, enabling us to evaluate model performance. We focused on eight species of katydids that the model identified with high precision (generally greater than 0.90) and moderate-to-high recall (minimum 0.35), ensuring that detections were generally correct and that many calls were detected. These results suggest that moonlight has modest effects on the amount of calling, with the magnitude and direction of effect varying by species: half of the species showed positive effects of light and half showed negative. These findings emphasize the importance of understanding natural history for anticipating how biological communities respond to moonlight. The methods applied in this project highlight the emerging opportunities for evaluating large quantities of data with machine learning models to address ecological questions over space and time. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'. [ABSTRACT FROM AUTHOR]

Passive acoustic monitoring (PAM) is a powerful tool for studying ecosystems. However, its effective application in tropical environments, particularly for insects, poses distinct challenges. Neotropical katydids produce complex species-specific calls, spanning mere milliseconds to seconds and spread across broad audible and ultrasonic frequencies. However, subtle differences in inter-pulse intervals or central frequencies are often the only discriminatory traits. These extremities, coupled with low source levels and susceptibility to masking by ambient noise, challenge species identification in PAM recordings. This study aimed to develop a deep learning-based solution to automate the recognition of 31 katydid species of interest in a biodiverse Panamanian forest with over 80 katydid species. Besides the innate challenges, our efforts were also encumbered by a limited and imbalanced initial training dataset comprising domain-mismatched recordings. To overcome these, we applied rigorous data engineering, improving input variance through controlled playback re-recordings and by employing physics-based data augmentation techniques, and tuning signal-processing, model and training parameters to produce a custom well-fit solution. Methods developed here are incorporated into Koogu, an open-source Python-based toolbox for developing deep learning-based bioacoustic analysis solutions. The parametric implementations offer a valuable resource, enhancing the capabilities of PAM for studying insects in tropical ecosystems. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'. [ABSTRACT FROM AUTHOR]

A survey on orthoptera in the transition zone between the Patagonian and Subantarctic regions of Argentina, along the Atlantic coast, was conducted to improve knowledge on these insects, which in these extreme areas have evolved into peculiar species, indicative to understand the biogeographical limits of this order of insects. New data have emerged on highly specialized genera such as Bufonacris and Astroma while other more generalist genera such as Sinipta have shown considerable expansion southwards, probably favoured by warmer climatic conditions. A new genus and species are described here for the first time: Caimanellus gen. nov. with the species Caimanellus australis sp. nov., at present the southernmost representative of the Phaneropterinae ever recorded. More general considerations on the evolution of the distributional limits of this large group of orthopterans are here discussed. [ABSTRACT FROM AUTHOR]

The expansion of forest cover and intensification of agriculture represent the main threats to the bush cricket Saga pedo, currently listed as Vulnerable globally by the IUCN and included in Annex IV of the European Union Habitats Directive. Gathering information on its ecology and population size is challenging due to its low abundance and localized distribution. Additionally, the elusive and cryptic behavior of this species reduces the likelihood of its detection, potentially resulting in population underestimations. Thus, in this study, we aimed to (1) estimate S. pedo population size in relation to environmental variables and prey availability and (2) predict abundance of S. pedo in our study area for future monitoring in nearby territories. We found that the population of S. pedo in our study area consists of 197 (±115) individuals with a detection probability of 21.01% (±11.09). Detection probability of S. pedo further decreases on windy days. Moreover, we found that the investigated population of S. pedo occupies suboptimal areas, as highlighted not only by the predicted abundances but also by the association between S. pedo and other subfamilies of orthoptera that are ecologically very distant from our target species and mostly linked to mesophilic biotopes. Most of the individuals we observed are concentrated in small clearings completely within wooded matrices and therefore isolated from each other. Based on our results, it is possible that forest expansion toward open meadows represents the main threat to this population, transforming the clearings and xeric meadows (to which S. pedo is linked) into small and fragmented patches that are suboptimal and insufficient to host viable populations. [ABSTRACT FROM AUTHOR]

Orthoptera is one of the most conspicuous groups of insects in any landscape. However, limited data on this group of insects have been published for European Russia. This article describes an occurrence dataset providing primary data on Orthoptera and Mantodea in European Russia, covering areas from the Kaluga region to Tatarstan and from the Nizhny Novgorod region to the Saratov region. A notable aspect of the dataset is the using of a wide range of sample methods, including acoustic observation, sweep net, pitfall traps, Malaise traps, pan traps, window traps, and beer traps. In total, 64.238 specimens were sampled across 1,186 plots. The dataset includes 7.095 occurrences representing 91 species of Orthoptera and 1 species of Mantodea. The number of plots, occurrences, and specimens is provided for each species in the article. The contribution of different sampling methods to insect identification is discussed. The latitudinal and longitudinal distributions of the species within the study area are analyzed.

Abstract In the Neotropical Region, Phlugidini is the most diverse tribe of Meconematinae, with 62 valid species in 10 genera, six of them recorded from Brazil. Brachyphlugis gen. nov. is described herein based on two new species, Brachyphlugis longicercalis sp. nov. (type species) and Brachyphlugis curvata sp. nov., collected in Parque Nacional do Itatiaia and Reserva Biológica do Tinguá, both in the Atlantic Forest of Rio de Janeiro State. The new genus is most similar to Neophlugis, but it can be distinguished from the latter and other neotropical Phlugidini by the following combination of characteristics: (1) mandibles symmetrical; (2) tegmen extending beyond metanotum; (3) pronotal disk posterior margin convex; (4) tenth tergite strongly projected and downcurved; (5) male cercus pronounced with a larger base and acuminate apex; (6) paraproct modified with developed spine; (7) male subgenital plate with two distolateral projections connected to a pair of styles; and (8) female subgenital plate wider than long, posterior margin with two projections. An up-to-date key to neotropical Phlugidini genera is also provided.

The complex and dynamic history of the Anatolian Peninsula during the Pleistocene set the stage for species diversification. However, the evolutionary history of biodiversity in the region is shrouded by the challenges of studying species divergence in the recent, dynamic past. Here, we study the Poecilimon bosphoricus (PB) species group to understand how the bush crickets' diversification and the regions' complex history are coupled. Specifically, using sequences of two mitochondrial and two nuclear gene segments from over 500 individuals for a comprehensive set of taxa with extensive geographic sampling, we infer the phylogenetic and geographic setting of species divergence. In addition, we use the molecular data to examine hypothesized species boundaries that were defined morphologically. Our analyses of the timing of divergence confirm the recent origin of the PB complex, indicating its diversification coincided with the dynamic geology and climate of the Pleistocene. Moreover, the geography of divergence suggests a history of fragmentation followed by admixture of populations, suggestive of a ring species. However, the evolutionary history based on genetic divergence conflicts with morphologically defined species boundaries raising the prospects that incipient species divergences may be relatively ephemeral. As such, the morphological differences observed in the PB complex may not to be sufficient to have prevented homogenizing gene flow in the past. Alternatively, with the recent origin of the complex, the lack of time for lineage sorting may underlie the discord between morphological species boundaries and genetic differentiation. Under either hypothesis, geography—not taxonomy—is the best predictor of genetic divergence. [ABSTRACT FROM AUTHOR]

Simple Summary: Grasshopper and cricket (Orthoptera) mass occurrences represent an unusually large increase in populations of certain species. Grasshopper species known as locusts are well known to cause severe damage to many crops. The severity of each outbreak depends on the species and on a wide range of ecological factors, including temperature and rainfall regime. In Croatia, a small country in SE Europe, there has never been systematic research on these Orthoptera species, and this phenomenon is regarded as a rare event despite several huge outbreaks being reported in the past. For the first time, all known mass occurrences of grasshoppers, locusts, crickets, bush-crickets, and mole crickets (of the order Orthoptera) from Croatia are summarized. The study represents a historical overview of all Orthoptera mass occurrences known based on the literature but also provides many new records. It seems that Orthoptera mass occurrences are not rare in the country at all, especially in the Mediterranean part. The present situation suggests that thorough research into locusts as agricultural pests in Croatia should be conducted to determine the potential threat to the local economy and with special emphasis on the Adriatic region. The trends of climate change in the Mediterranean imply a rise in locust destructiveness risk in the near future and invites further research. During the last century, well-known locust species, such as Calliptamus italicus and Dociostaurus maroccanus, have produced outbreaks of varying degrees in the Balkans. The literature data on outbreaks in the region are scarce, and Croatia is not an exception. This study summarized the data on 23 Orthoptera mass occurrences in Croatia from 1900 to 2023 from 28 localities, representing 12 species. This is a low level of outbreak activity compared with other locust and pest grasshopper species in other parts of the world. The species with the most reporting is C. italicus with altogether six mass occurrences, while second is Barbitistes ocskayi and Miramella irena with three records, and in the third, place D. maroccanus and Gryllotalpa sp., each with two mass occurrences having been reported. One of the most notable swarms is that of Anacridium aegyptium which occurred around Šibenik in 1998, and this paper provides the first account of it, 25 years after it took place. The most recent outbreaks took place in 2022, and the most notable one was that of D. maroccanus swarm in Štikovo. The 2022 and 2023 reports were brief and muted, despite the affected agriculturists claiming significant damages. [ABSTRACT FROM AUTHOR]

For animals that produce species‐specific audible sounds, environmental recordings combined with automated acoustic monitoring software (passive acoustic monitoring [PAM]) may be an effective monitoring tool because it allows audio data from many, widely distributed autonomous recording units (ARUs) to be processed in a relatively short period of time. Males of many insect species produce loud, species‐specific mating songs, yet acoustic insects have received less attention from PAM relative to vertebrates.We evaluated the use of PAM to monitor, Roeseliana roeselii (Orthoptera, Tettigoniidae), an acoustic insect that has expanded its range to Alberta, Canada, far outside its naturalized North American range. We analysed environmental recordings from ARUs: (1) at two control sites known to be occupied by R. roeselii and (2) across Alberta established by the Alberta Biodiversity Monitoring Institute (ABMI) to search for new populations.PAM successfully detected R. roeselii at the two control sites, but not at any of the 73 ABMI sites that we analysed. Despite the failure to detect new locations of R. roeselii, our analysis of ABMI environmental recordings detected several other species of acoustic insects, including Orchelimum gladiator, Gryllus sp. and Allonemobius spp.Our results add to the growing body of work showing the feasibility of using PAM for acoustic insects. We make suggestions for how to maximize the effectiveness of this monitoring tool for the conservation and management of singing insects in North America. [ABSTRACT FROM AUTHOR]

Introduction: Knowledge on the mobility of threatened species is a clue to understanding population dynamics and is needed to develop appropriate conservation strategies. Here, we investigate movement patterns of the Bei-Bienko's Plump Bush-cricket (Isophya beybienkoi), an example of a flightless and critically endangered species endemic to the Slovak Karst (southern Slovakia, Central Europe). The capture-mark-recapture method was used to estimate the mobility of the species using fluorescent dye as a marking medium. We found that the mean (± SD) daily distance travelled by this species was only 3.2 ± 2.6 m, with significant differences between males (4.1 ± 3.0 m) and females (2.7 ± 2.1 m). Our results indicate that I. beybienkoi is a short-distance disperser. Males disappeared faster than females from the study plots (at maximum, two females were recaptured even after 41 days). The observed movement patterns suggest that the most urgent conservation measure for this species is to improve the habitat quality of sites, which suffer from overgrowth, and to maintain the quality of other suitable sites that might increase the size of the existing subpopulations. Implications for insect conservation: Our results show that I. beybienkoi is a short-distance disperser and wanders only within its optimal habitat. Hence, to incorporate movement behaviour into conservation, one of the measures that should mitigate this threat is to preserve or improve the quality of habitats that suffer from overgrowth, in order to increase the size of existing subpopulations. The observed movement patterns suggest that the species is probably incapable of responding to changes in the availability of suitable habitats by dispersing, indicating a limited exchange of individuals between isolated populations. Thus, to enhance structurally diverse mosaic of high-quality habitats, restoration of migration corridors former used as movement corridors for grazing animals may support the dispersal of the threatened bush-cricket. [ABSTRACT FROM AUTHOR]

Eupholidoptera kekrops sp. nov. belonging to the E. prasina group, is described from mainland Greece. The new species is the first known member of this group from mainland Greece and mainland Europe. Differentiating morphological characteristics, mainly of the subgenital plate and titilator, are presented. [ABSTRACT FROM AUTHOR]

Identifying the drivers of microgeographic speciation (i.e. speciation over small, local geographic scales) is key to understand the origin of speciose groups. Here, we use genomic data to infer the demographic processes underlying diversification in Poecilimon luschani (Orthoptera: Tettigoniidae), a species complex belonging to the most diverse genus of bush crickets from the Mediterranean region (>170 taxa) that comprises three recognized subspecies with small allopatric distributions in the topographically complex Teke Peninsula, southwestern Anatolia. Phylogenomic reconstructions that include all other taxa within the species group confirmed that subspecies of P. luschani originated from a common ancestor during the Pleistocene, supporting recent (<1 Ma) diversification within a small geographical area (ca. 120 × 80 km). Genetic clustering analyses corroborated the distinctiveness of each subspecies and the cohesiveness of their respective populations, with abrupt genetic discontinuities coinciding with contemporary range boundaries. Indeed, our analyses uncovered the presence of two sympatric cryptic sister lineages that diverged <300 ka ago and do not admix despite being co-distributed. Collectively, these results support that all lineages within the complex represent independently evolving entities corresponding to full-fledged species. Statistical evaluation of alternative models of speciation strongly supports a scenario of divergence in isolation followed by a period of limited gene flow during the last glacial period, when all lineages experienced marked expansions according to demographic reconstructions. Our study exemplifies how localized allopatric divergence and fast evolution of reproductive isolation can promote microgeographic speciation and explain the high rates of endemism characterizing biodiversity hotspots. [ABSTRACT FROM AUTHOR]

The composition, diagnostic characters, and some species of two genera of the tribe Holochlorini (Psyrana Uvarov, 1940 and Pseudopsyra Hebard, 1922) are considered. Each of these genera is subdivided into two subgenera, and the following new taxa are described: Adentipsyrasubgen. n. (in Psyrana s. l.), Psyrana (Psyrana) simulatorsp. n.,Psyrana (Psyrana) imitativasp. n.,Psyrana (Psyrana) cercomorphasp. n.,Psyrana (Psyrana) estrinisp. n.,Psyrana (Psyrana) tamdaosp. n.,Psyrana (Psyrana) papuasp. n.,Psyrana (Psyrana) papua halmaherasubsp. n.,Psyrana (Psyrana) signatasp. n.,Psyrana (Psyrana) parasignatasp. n.,Psyrana (Psyrana) parasignata simplexsubsp. n.,Psyrana (Psyrana) striatasp. n.,Psyrana (Psyrana) parastriatasp. n.,Psyrana (Psyrana) amplasp. n.,Psyrana (Psyrana) ministriatasp. n.,Psyrana (Adentipsyra) pulchrasp. n.,Psyrana (Adentipsyra) pulchra proximasubsp. n.,Diapsyrasubgen. n. (in Pseudopsyra s. l.), Pseudopsyra (Pseudopsyra) carinatasp. n.,Pseudopsyra (Pseudopsyra) spinatasp. n.,Pseudopsyra (Pseudopsyra) dentatasp. n.,Pseudopsyra (Pseudopsyra) curvatasp. n.,Pseudopsyra (Pseudopsyra) fomichevisp. n.,Pseudopsyra (Diapsyra) thaiensissp. n.,Pseudopsyra (Diapsyra) vietensissp. n., and Pseudopsyra (Diapsyra) latasp. n. The lectotype of Pseudopsyra (Pseudopsyra) sondaica (Carl, 1921), comb. n. is designated, the female of Pseudopsyra (Pseudopsyra) taksini Tan et al., 2017 is described for the first time, and some other new data on a few previously described species are provided. [ABSTRACT FROM AUTHOR]

The article discusses the Bug Club Summer Camp 2023, which was the first camp held since 2018 due to the Covid-19 pandemic and was a highly anticipated event following a five-year hiatus due to the pandemic, and it featured activities like insect trapping and exploration of Wytham Woods, showcasing a variety of insect species in the process. Topics include activities such as insect trapping, a bug hunt in Wytham Woods, and the diverse range of insect species encountered during the camp.

Simple Summary: Species interact with each other in many ways, such as predation, mutualism, or competition, ultimately affecting each other's evolution, reducing the negative effects of these interactions and/or increasing the positive ones. We studied a parasitic fly that uses different katydid species as hosts for its larvae sequentially at different times during its breeding season. The fly larvae kill the host when they emerge, setting up multiple arms races between the fly and each of the hosts. The hosts are selected to ameliorate the negative impact of parasitism, whereas the parasitoid is selected to use all host species well for the population to persist. We compared host use and the ability of fly pupae to develop into adults across four katydid hosts. The parasitism rate varied between ~14% and 73%, yet host use was similar for many larval measurements across hosts. However, one species was a particularly poor host for the fly based on fly pupa development. We suggest that currently, this poor host strongly influences the evolution of the fly in this arms race to improve its utilization of this host. Understanding how species interact and affect each other is important to predict their evolution and manage species of human relevance, such as parasites, plant pests, or vectors of disease. Antagonistic species relationships such as parasitoid/host interactions lead to evolutionary arms races between species. Many parasitoids use more than one host species, requiring the parasitoid to adapt to multiple hosts, sometimes being the leader or the follower in the evolutionary back-and-forth between species. Thus, multi-species interactions are dynamic and show temporary evolutionary outcomes at a given point in time. We investigated the interactions of the multivoltine parasitoid fly Ormia lineifrons that uses different katydid hosts for each of its fly generations sequentially over time. We hypothesized that this fly is adapted to utilizing all hosts equally well for the population to persist. We quantified and compared the fly's development in each of the four Neoconocephalus hosts. Cumulative parasitism rates ranged between ~14% and 73%, but parasitoid load and development time did not differ across host species. Yet, pupal size was lowest for flies using N. velox as a host compared to N. triops and other host species. Successful development from pupa to adult fly differed across host species, with flies emerging from N. triops displaying a significantly lower development success rate than those emerging from N. velox and the other two hosts. Interestingly, N. triops and N. velox did not differ in size and were smaller than N. robustus and N. nebrascensis hosts. Thus, O. lineifrons utilized all hosts but displayed especially low ability to develop in N. triops, potentially due to differences in the nutritional status of the host. In the multi-species interactions between the fly and its hosts, the poor use of N. triops may currently affect the fly's evolution the most. Similarities and differences across host utilization and their evolutionary background are discussed. [ABSTRACT FROM AUTHOR]

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An updated checklist of the order Orthoptera of Kerala is provided. Eighty-five species have been added to the existing checklist. A total of 215 species and 21 subspecies belonging to 154 genera under 18 families of two suborders are enumerated along with their distributional data across the state. Suborders Caelifera and Ensifera are represented by 127 and 88 species, respectively. © 2023 Association for Advancement of Entomology. [ABSTRACT FROM AUTHOR]

Mitochondrial gene order has contributed to the elucidation of evolutionary relationships in several animal groups. It generally has found its application as a phylogenetic marker for deep nodes. Yet, in Orthoptera limited research has been performed on the gene order, although the group represents one of the oldest insect orders. We performed a comprehensive study on mitochondrial genome rearrangements (MTRs) within Orthoptera in the context of mitogenomic sequence‐based phylogeny. We used 280 published mitogenome sequences from 256 species, including three outgroup species, to reconstruct a molecular phylogeny. Using a heuristic approach, we assigned MTR scenarios to the edges of the phylogenetic tree and reconstructed ancestral gene orders to identify possible synapomorphies in Orthoptera. We found all types of MTRs in our dataset: inversions, transpositions, inverse transpositions, and tandem‐duplication/random loss events (TDRL). Most of the suggested MTRs were in single and unrelated species. Out of five MTRs which were unique in subgroups of Orthoptera, we suggest four of them to be synapomorphies; those were in the infraorder Acrididea, in the tribe Holochlorini, in the subfamily Pseudophyllinae, and in the two families Phalangopsidae and Gryllidae or their common ancestor (leading to the relationship ((Phalangopsidae + Gryllidae) + Trigonidiidae)). However, similar MTRs have been found in distant insect lineages. Our findings suggest convergent evolution of specific mitochondrial gene orders in several species, deviant from the evolution of the mitogenome DNA sequence. As most MTRs were detected at terminal nodes, a phylogenetic inference of deeper nodes based on MTRs is not supported. Hence, the marker does not seem to aid resolving the phylogeny of Orthoptera, but adds further evidence for the complex evolution of the whole group, especially at the genetic and genomic levels. The results indicate a high demand for more research on patterns and underlying mechanisms of MTR events in Orthoptera. [ABSTRACT FROM AUTHOR]

Inconspicuous species challenge conservationists when it comes to delineate long-term conservation planning or assess their status, particularly when their actual distribution is poorly known. Invertebrates in particular feature among the less represented taxa in conservation assessments. Here we follow a multidisciplinary approach for assessing the conservation coverage and address future management of the threatened orthopteran Saga pedo across Europe, shedding light on its ecological preferences and associations with protected habitats at continental and regional scales. When assessing coverage by Natura2000 and Nationally Protected Areas, we found that ca. 30% of the known populations of the species are currently not protected across Europe. However, this value is likely to be an underestimate as our species distribution models showed that ca. 70% of the potential range is not protected. At regional scale, we disclose that the species is more likely to occur in legally protected dry grassland habitat types than in non-protected grassland, yet not all protected habitats seem to represent an effective tool for the species' conservation. Implications for insect conservation: Taken together, our results provide an effective framework for addressing knowledge gaps and evaluate the conservation coverage not only of our target species, but more in general of poorly investigated species, at the same time pointing at the urgent need of transnational, coordinated, and increased efforts in monitoring and conserving insects, particularly in the case of threatened species. [ABSTRACT FROM AUTHOR]

The diurnal bees, lepidopterans, and other pollinators are among the most studied flower‐visiting insect taxa. They mostly play distinct functions in temperate grasslands and ecotones of grassland‐forest mosaics (such as in forest steppes). Although orthopterans are widely distributed in these habitats, however, their flower visitation is nearly unknown, especially in the temperate zone. During the development of traps with chemical lures to catch Lepidoptera pests, large numbers of Orthoptera were caught that provide a chance for studying the flower visitation and odor and indirectly the host plant preference of seven temperate zone Tettigoniidae species. Data on the attractivity of isoamyl alcohol‐based semisynthetic lures for Meconema thalassinum and efficiency of phenylacetaldehyde‐based lures on Leptophyes albovittata and Phaneroptera falcata were reported for the first time. Additionally, analysis of nature photos collected from internet sources, as part of a passive citizen science also supports the revealed preference of these species. Based on photos, the studied orthopterans mainly visit Asteraceae species including the most preferred Tanacetum vulgare, Pulicaria dysenterica, Achillea millefolium, Solidago canadensis, and Centaurea scabiosa. Based on catches of volatile traps, the first data were recorded on the attractivity of phenylacetaldehyde‐ and isoamyl alcohol‐based lures on three temperate zone Orthoptera species. Results of a passive citizen science study strengthen these results that may increase the knowledge on the host plant and habitat preference of Orthoptera species. [ABSTRACT FROM AUTHOR]

This study focuses on the genus Dioncomena and its acoustics, particularly the unique songs produced by male Dioncomena that consist of several distinct elements in a fixed sequence, culminating in a coda that typically elicits a response from a receptive female. We also examine the inflated pronotal lobes, which we term prebullae, that are prominently developed in some Dioncomena species but not in others. We discuss the role of prebullae in the context of acoustic communication in Dioncomena and other related Phaneropterini genera that have similar lateral pronotal lobes. We found that prebullae size is correlated with habitat distribution, with larger prebullae occurring in isolated species while aggregation-prone species have smaller or less pronounced prebullae. Using micro-computer tomography we show sexual dimorphism in the 3D geometry of the acoustic tracheae, being larger in the male. Interestingly, the tracheae are coupled by a septum, like in field crickets, which suggests potential cross talk. We define three groups of Dioncomena based on altitude preferences, ecology, color patterns, and songs: the jagoi-, tanneri-, and ornata-groups. We describe the songs of several species, including newly identified species such as D. flavoviridis sp. nov., D. magombera sp. nov., D. ngurumontana sp. nov., D. sanje sp. nov., D. tanneri, D. versicolor sp. nov., and D. zernyi. We also provide information on the nymphs, development time, and mating behavior of various species reared in the laboratory, shedding light on their phenology and adaptations to their habitats. [ABSTRACT FROM AUTHOR]

Deimatic behaviour is performed by prey when attacked by predators as part of an antipredator strategy. The behaviour is part of a sequence that consists of several defences, for example they can be preceded by camouflage and followed by a hidden putatively aposematic signal that is only revealed when the deimatic behaviour is performed. When displaying their hidden signal, mountain katydids (Acripeza reticulata) hold their wings vertically, exposing striking red and black stripes with blue spots and oozing an alkaloid‐rich chemical defence derived from its Senecio diet. Understanding differences and interactions between deimatism and aposematism has proven problematic, so in this study we isolated the putative aposematic signal of the mountain katydid's antipredator strategy to measure its survival value in the absence of their deimatic behaviour. We manipulated two aspects of the mountain katydid's signal, colour pattern and whole body shape during display. We deployed five kinds of clay models, one negative control and four katydid‐like treatments, in 15 grids across part of the mountain katydid's distribution to test the hypothesis that their hidden signal is aposematic. If this hypothesis holds true, we expected that the models, which most closely resembled real katydids would be attacked the least. Instead, we found that models that most closely resembled real katydids were the most likely to be attacked. We suggest several ideas to explain these results, including that the deimatic phase of the katydid's display, the change from a camouflaged state to exposing its hidden signal, may have important protective value. [ABSTRACT FROM AUTHOR]

Animals adopt circadian rhythms and diel calling patterns to ensure successful breeding, avoid predators, and reduce intra- and inter-species competition. We determine the diel calling behaviour of the bush cricket, Acanthoplus discoidalis, across different vegetation types in the southern Kalahari, and whether any variation in calling behaviour exists across the different regions of the landscape. We identify potential environmental drivers impacting its calling behaviour, as well as any impact temperature and wind may have on the species' calling behaviour. Acanthoplus discoidalis was recorded singing in all vegetation types, calling starts around 10h00 and ceases at 00h00, with a peak from 15h00 to 23h00, a longer peak than expected based on previous studies. This pattern was consistent across all vegetation types, although calling intensity was less in mountainous, rocky, and windy areas. A likely explanation for the expanded diel pattern is that sampling occurred during a mass emergence of the species, and so a wider temporal niche could be a response to reduce intraspecies competition for females. Furthermore, this diel calling pattern may reduce encounters with predators, which are typically either strictly nocturnal or diurnal, yet it is likely this species relies on physical defences over acoustic adaptations to avoid predation. [ABSTRACT FROM AUTHOR]

Tettigoniidae is the most diverse family within Orthoptera; its species inhabit forests all over the world, with the tropical and subtropical forests hosting the greatest number of species. Brazil is the country with the largest remnants of preserved forests, and is the country with the most recorded species of katydids. Even so, only two faunistic inventories have been carried out, both in the Atlantic Forest. The main objective of this work was to provide a faunistic inventory of Tettigoniidae in the Guartelá State Park, Paraná State, Southern Brazil, a park that preserves both the Atlantic Forest and Cerrado biomes. In this contribution 57 species of Tettigoniidae were recorded, with Phaneropterinae being the most diverse subfamily, represented by 36 species; Conocephalinae was represented by 19 species, whereas Meconematinae and Pseudophyllinae had only one species each. Among these species, five are new and are herein described: Conocephalus (Anisoptera) guartela sp. nov. (Conocephalinae: Conocephalini), Anaulacomera (Cervicercora) melloi sp. nov., Anaulacomera (Anaulacomera) szinwelskii sp. nov. (Phaneropterinae: Phaneropterini), Anisophya hemanuelae sp. nov., and Xenicola nunoi sp. nov. (Phaneropterinae: Odonturini). The calling songs of three of the new species were also recorded and are herein described and discussed, as well as the sounds of all species of the subgenus Conocephalus (Anisoptera). The relationship of some katydid species to plants is also described and discussed, as well as the feeding habits and other aspects of natural history, and the presence of some species in the driest areas of the park, representing the Cerrado, the biome with the lowest number of tetigonids recorded so far. [ABSTRACT FROM AUTHOR]

To forage efficiently, animals should selectively attend to and remember the cues of food that best predict future meals. One hypothesis is that animals with different foraging strategies should vary in their reliance on spatial versus feature cues. Specifically, animals that store food in dispersed caches or that feed on spatially stable food, such as fruits or flowers, should be relatively biased towards learning a meal's location, whereas predators that hunt mobile prey should instead be relatively biased towards learning feature cues such as odor or sound. Several authors have predicted that nectar-feeding and fruit-feeding bats would rely relatively more on spatial cues, whereas closely related predatory bats would rely more on feature cues, yet no experiment has compared these two foraging strategies under the same conditions. To test this hypothesis, we compared learning in the frugivorous bat, Artibeus jamaicensis , and the predatory bat, Lophostoma silvicolum, which hunts katydids using acoustic cues. We trained bats to find food paired with a unique and novel odor, sound, and location. To assess which cues each bat had learned, we then dissociated these cues to create conflicting information. Rather than finding that the frugivore and predator clearly differ in their relative reliance on spatial versus feature cues, we found that both species used spatial cues over sounds or odors in subsequent foraging decisions. We interpret these results alongside past findings on how foraging animals use spatial cues versus feature cues, and explore why spatial cues may be fundamentally more rich, salient, or memorable. [ABSTRACT FROM AUTHOR]

The auditory system of the katydid is an established model system for studies of hearing, predator-prey interactions, and cochlea dynamics. The components peripheral to the ear substantially influence the hearing threshold, with an internal auditory trachea tuned to the calling song of conspecifics, and external pinnae capable of enhancing ultrasounds for predator detection. The trade-off between such auditory pathways has been subject to multiple discussions, but received little experimental validation. In the most ultrasonic katydids (Pseudophyllinae and Meconematinae), it has been suggested that the external auditory pathway is of greater importance than the internal one, but the biophysical properties of the pinnae and tracheae in such groups have not been compared. Here, we describe the bioacoustics of a new species of pseudophylline katydid, Eubliastes viridicorpus. This species is found to produce a pure tone two-syllable song at 23.4 kHz, similar to other members of the genus. Using micro-CT scanning and finite element modelling, we describe the biophysical tuning of the internal auditory tracheae, and use 3D printed model experiments to investigate external auditory pinnae resonances. By modelling the natural resonant frequencies of the ear, we provide evidence that the acoustic trachea of E. viridicorpus female is tuned to the male song frequency. Experiments on 3D printed models of the pinnae demonstrate that E. viridicorpus has an external auditory pathway capable of broadband ultrasound amplification, providing pressure gains across an effective frequency range of 20–200 kHz, which could also provide enhanced reception of the male song. The importance of pinnae in ultrasonic rainforest katydids is discussed. [ABSTRACT FROM AUTHOR]

Insect songs are compelling features of the natural environment, and insects provide diverse model systems merging the worlds of entomologists and engineers. An unusually well-preserved fossil katydid highlights the synergy between these disciplines and offers a compelling glimpse into the deep past. [ABSTRACT FROM AUTHOR]

The author recounts his observation of a Red-backed Shrike Lanius collurio foraging on hay meadows near village of Klimonty in Siedlce district, east-central Poland on August 30, 2020. He discusses the behavior of the bird, the prey items it was catching, and the widespread dispersal of the European Mantis across Europe.

Although outbreaks of rare species are unusual, several insect species have become emerging pests probably due to the ongoing environmental changes. Barbitistes vicetinus was first described in 1993 as an endemic bush‐cricket of north‐east Italy and was considered rare until 2008, when it became an established pest, causing severe damages to forests and crops. The possible role of temperature in changing its life cycle has still to be fully understood. Here, we explored the effect of summer temperature on egg diapause and the effect of winter temperature on egg survival. Field observations showed that the proportion of embryos that can complete development at the end of summer ranged from zero to nearly 90% depending on summer temperatures. A substantial shift in the rate of development from 20% to nearly 80% occurred in a thermal range of about 1 °C. On the contrary, overwinter egg survival was high and constant (90%) across a wide range of winter temperatures that go well beyond both the cold and warm thermal limits of the current species range. Overall, the results suggest a potential key role of summer temperature warming on the outbreak propensity of this species that is able to switch from a multiyear to an annual life cycle with just a 1–2 °C warming. [ABSTRACT FROM AUTHOR]

Typical cockroaches are flat, broad, with large pronotum and wings covering the body. This conserved morphotype dates back to the Carboniferous, during which the ancestral cockroaches, or roachoids, originated. On the other hand, the ovipositor of cockroaches gradually reduced during the Mesozoic, coupled with a major shift of reproductive strategy. By the Cretaceous, long external ovipositors became rare, most cockroaches used very short or even hidden internal ovipositors to fabricate egg cases (oothecae), which is an innovation for egg protection. Here, we describe two cockroaches from mid-Cretaceous Myanmar amber: Ensiferoblatta oecanthoides gen. et sp. nov. (Ensiferoblattidae fam. nov.) and Proceroblatta colossea gen. et sp. nov. They are slim, elongate, fusiform, with longitudinal pronotum, and have long external ovipositors. The combination of these traits represents a unique morphotype, which resembles crickets and katydids (Ensifera) more than general cockroaches. Ensiferoblatta and Proceroblatta may be arboreal, feeding on and/or laying eggs into certain angiosperms that newly emerged. Their open habit causes latent impairment to viability, and may contribute to their extinction. These new taxa are the youngest members of the ancient, extinct group of cockroaches, namely Eoblattodea, which are characterized by long ovipositors. We speculate that the extinction of certain gymnosperm hosts almost ended the 200-My triumph of Eoblattodea. Despite an attempt to adapt to angiosperm hosts, Ensiferoblatta, Proceroblatta and suchlike cockroaches as an evolutionary dead end failed to save Eoblattodea from extinction. The lack of protection for eggs (maternal care in particular) might accelerate the extinction of Eoblattodea as a whole. [ABSTRACT FROM AUTHOR]

The study provides the first description of acoustic communities from a subtropical rainforest in Northeast India and a previously unexplored site from the Western Ghats. We describe call structures of 15 katydid species from the Indian subcontinent. The habitat and seasonal variations of the communities were investigated at both sites. Most species observed produced ultrasonic broadband calls (bandwidth: 11.07–42.5 kHz); only two Pseudophyllinae members produced pure tone calls. The study includes calls of two previously undescribed species of the genus Ducetia (subfamily: Phaneropterinae) from the subcontinent. We observed diverse acoustic communities at both sites represented by five major subfamilies: Conocephalinae, Hexacentriane, Mecopodinae, Phaneropterinae and Pseudophyllinae. The acoustic communities at each site exhibited seasonal variations and habitat preferences. The post-monsoon season had a richer community composition than the dry season. We compared differences in the community compositions between habitats using a presence–absence matrix based on 526 individuals from the two sites. Species composition was found to be different among habitats (stress =.06, dimension: 2), with ANOSIM indicating separation of species among understorey, shrubland and grassland habitats. [ABSTRACT FROM AUTHOR]

Isophya modestior (Orthoptera: Tettigoniidae) is a species distributed in central and south-eastern Europe, where its distribution is largely separated by two large rivers (Sava and Danube). Since previous studies on the song and morphology of the stridulatory file across its complete geographic range showed that the species is separated into two main groups, we decided to use phylogenetic and karyological analyses in order to evaluate the status of the previously analysed populations. Phylogenetic analyses showed the existence of two major clades within I. modestior with very high bootstrap values and posterior probabilities—Clade A: present on the Balkan Peninsula, Slovenia (Inner Carniola), Italy, Pannonian Serbia (Vršac Mts and Deronje) and Austria (Burgenland and Lower Austria); Clade B: present in Slovenia (Upper Carniola), Croatia and Austria (Carinthia), Pannonian Serbia (Fruška Gora Mt.) and Hungary. A comparison of chromosomes of 51 specimens revealed discrete differences between their karyotypes. The physical characteristics of the karyotypes included chromosome number (2n), sex chromosome (X) morphology and C-banding patterns. The standard chromosome complement of 50 specimens from different localities is characterized by 2 n  = 30 + X0 in males. In one male collected in Fruška Gora Mt. (Andrevlje), the chromosome number was reduced to 2 n  = 28 + neo-XY. Therefore, further cytogenetic studies involving larger samples, especially from Fruška Gora Mt. are needed in order to gain a more comprehensive view of the chromosome evolution in this group of Isophya species. [ABSTRACT FROM AUTHOR]

Morphological and behavioural differences between the sexes often make one sex of a species more vulnerable to predation than the other. Onomarchus uninotatus, a canopy katydid, forms an important component of the diet of the insectivorous bat Megaderma spasma. Examination of culled prey remains in M. spasma roosts suggested that female O. uninotatus may be at higher risk of predation than males. As in many insects, the females of O. uninotatus are larger and heavier and might be easier for predators to detect and capture and/or preferred for their higher nutritive value. We tested these hypotheses by conducting behavioural experiments in an outdoor enclosure, examining the bat predator approach to free-flying O. uninotatus and their capture success. We found that the flying female and male katydids were equally likely to be approached, but males were captured more by M. spasma, with a weak effect. This indicates that females may have a better escape strategy after being approached. We then asked whether females were at higher risk of predation because they moved more often or for longer durations across trees than males, in search of mates and egg-laying sites. We investigated landscape-level movement patterns of O. uninotatus females and males using VHF radio-telemetry. Females had 1.6 times higher frequency of movement and 1.8 times greater displacement across trees than males. This difference may be ecologically important and cause higher bat predation risk on females. Significance statement: Studying the factors affecting sex-specific levels of predation risk is crucial to better understand the natural selection and the hypothesised causes and consequences of sexual dimorphism. Katydid females, including Onomarchus uninotatus, are at a higher risk of bat predation than males, and flying is one of the most risky prey behaviours. Onomarchus uninotatus females are larger than males, which could make them easier to detect and capture. Our experiments involving free-flying bats and katydids showed, however, that bat approaches are similar for flying females and males. Females might be better at escaping bat captures after being approached. Katydid males typically broadcast acoustic signals, and females move towards these signals, potentially placing females at higher predation risk. Radio-telemetry studies revealed that on average, females were likely to move more often with greater displacements across trees, which may place them at higher risk of predation. [ABSTRACT FROM AUTHOR]

During the last century, well-known locust species, such as Calliptamus italicus and Dociostaurus maroccanus, have produced outbreaks of varying degrees in the Balkans. The literature data on outbreaks in the region are scarce, and Croatia is not an exception. This study summarized the data on 23 Orthoptera mass occurrences in Croatia from 1900 to 2023 from 28 localities, representing 12 species. This is a low level of outbreak activity compared with other locust and pest grasshopper species in other parts of the world. The species with the most reporting is C. italicus with altogether six mass occurrences, while second is Barbitistes ocskayi and Miramella irena with three records, and in the third, place D. maroccanus and Gryllotalpa sp., each with two mass occurrences having been reported. One of the most notable swarms is that of Anacridium aegyptium which occurred around Šibenik in 1998, and this paper provides the first account of it, 25 years after it took place. The most recent outbreaks took place in 2022, and the most notable one was that of D. maroccanus swarm in Štikovo. The 2022 and 2023 reports were brief and muted, despite the affected agriculturists claiming significant damages.

Katydids produce sound for signaling and communication by stridulation of the tegmina. Unlike crickets, most katydids are known to sing at ultrasonic frequencies. This has drawn interest in the investigation of the biophysics of ultrasonic sound production, detection, evolution, and ecology (including predator-prey interactions) of these katydids. However, most of these studies are based on species from the Neotropics, while little is known about katydid species from the hyperdiverse region of Southeast Asia. To address this, a concerted effort to document, record, and describe the calling songs of Southeast Asian katydids, especially species that call at ultrasonic frequencies, was made. A study spanning two years (2018-2020) in the Malay Peninsula (Singapore and Malaysia), Borneo (Brunei Darussalam and Sabah), and the Philippines revealed previously unknown calls of 24 katydid species from four subfamilies. The calling songs of Southeast Asian katydid species are highly diversified in terms of time and frequency. Call structure can range from isolated syllables (e.g., Holochlora), continuous trills (e.g., Axylus philippinus), to short pulse-trains (e.g., Euanisous teuthroides) and complex echemes (e.g., Conocephalus spp.), with 87.5% of species having ultrasonic peak frequencies and 12.5% being considered extreme ultrasonic callers (peak frequency >40 kHz). The call spectrum ranges from tonal (e.g., spectral entropy is 6.8 in Casigneta sp. 2) to resonant (entropy is 8.8 in Conocephalus cognatus). Of the 24 species whose calls are described here, we imaged and described the soundproducing structures of 18. This study provides a preliminary overview of the acoustic diversity of katydids in Southeast Asia, and the authors hope to inspire further investigation into the bioacoustics of little-known katydids from these areas. Amassing a database of calling songs and soundproducing organ illustrations from different species is important to address taxonomic impediments while advancing our knowledge about the bioacoustics of Southeast Asian katydids. [ABSTRACT FROM AUTHOR]