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ZooKeys 2024The genus Gorochov, 1987 includes 10 species from Asia, with nine documented in China. In this study, a new species, He, , is described from Xizang, China....
The genus Gorochov, 1987 includes 10 species from Asia, with nine documented in China. In this study, a new species, He, , is described from Xizang, China. Morphologically, it resembles (Chopard, 1932) but can be distinguished by a smaller inner tympanum, dark-brown setae on the 5 segment of the maxillary palp, and a rounded apex on the ectoparamere. To validate our morphological inferences and support the description of as a new species, we performed a PCA based on bioacoustics parameters and molecular analysis. All species documented in China are distinguished by integrating their songs and DNA barcoding.
PubMed: 38487668
DOI: 10.3897/zookeys.1193.117612 -
Mobile DNA Mar 2024Transposable elements (TEs) are a major component of eukaryotic genomes and are present in almost all eukaryotic organisms. TEs are highly dynamic between and within...
Transposable elements (TEs) are a major component of eukaryotic genomes and are present in almost all eukaryotic organisms. TEs are highly dynamic between and within species, which significantly affects the general applicability of the TE databases. Orthoptera is the only known group in the class Insecta with a significantly enlarged genome (0.93-21.48 Gb). When analyzing the large genome using the existing TE public database, the efficiency of TE annotation is not satisfactory. To address this limitation, it becomes imperative to continually update the available TE resource library and the need for an Orthoptera-specific library as more insect genomes are publicly available. Here, we used the complete genome data of 12 Orthoptera species to de novo annotate TEs, then manually re-annotate the unclassified TEs to construct a non-redundant Orthoptera-specific TE library: Orthoptera-TElib. Orthoptera-TElib contains 24,021 TE entries including the re-annotated results of 13,964 unknown TEs. The naming of TE entries in Orthoptera-TElib adopts the same naming as RepeatMasker and Dfam and is encoded as the three-level form of "level1/level2-level3". Orthoptera-TElib can be directly used as an input reference database and is compatible with mainstream repetitive sequence analysis software such as RepeatMasker and dnaPipeTE. When analyzing TEs of Orthoptera species, Orthoptera-TElib performs better TE annotation as compared to Dfam and Repbase regardless of using low-coverage sequencing or genome assembly data. The most improved TE annotation result is Angaracris rhodopa, which has increased from 7.89% of the genome to 53.28%. Finally, Orthoptera-TElib is stored in Sqlite3 for the convenience of data updates and user access.
PubMed: 38486291
DOI: 10.1186/s13100-024-00316-x -
Biodiversity Data Journal 2024The migratory locust, (L.), a significant grasshopper species known for its ability to form large swarms and cause extensive damage to crops and vegetation, is subject...
The migratory locust, (L.), a significant grasshopper species known for its ability to form large swarms and cause extensive damage to crops and vegetation, is subject to the influence of climate change. This research paper employs geographic information system (GIS) and MaxEnt ecological modelling techniques to assess the impact of climate change on the distribution patterns of . Occurrence data and environmental variables are collected and analysed to create predictive models for the current and future distribution of the species. The study highlights the crucial role of climate factors, particularly temperature and precipitation, in determining the locust's distribution. The MaxEnt models exhibit high-performance indicators, accurately predicting the potential habitat suitability of . Additionally, specific bioclimatic variables, such as mean temperature and annual precipitation, are identified as significant factors influencing the species' presence. The generated future maps indicate how this species will invade new regions especially in Europe. Such results predict the risk of this destructive species for many agriculture communities as a direct result of a warming world. The research provides valuable insights into the complex relationship between locust distribution and environmental factors, enabling the development of effective strategies for locust management and early warning systems to mitigate the impact on agriculture and ecosystems.
PubMed: 38481856
DOI: 10.3897/BDJ.12.e115845 -
Current Opinion in Insect Science Jun 2024Detecting looming motion directly towards the insect is vital to its survival. Looming detection in two insects, flies and locusts, is described and contrasted. Pathways... (Review)
Review
Detecting looming motion directly towards the insect is vital to its survival. Looming detection in two insects, flies and locusts, is described and contrasted. Pathways using looming detectors to trigger action and their topographical layout in the brain is explored in relation to facilitating behavioural selection. Similar visual stimuli, such as looming motion, are processed by nearby glomeruli in the brain. Insect-inspired looming motion detectors are combined to detect and avoid collision in different scenarios by robots, vehicles and unmanned aerial vehicle (UAV)s.
Topics: Animals; Escape Reaction; Motion Perception; Diptera; Grasshoppers; Insecta; Vision, Ocular
PubMed: 38432555
DOI: 10.1016/j.cois.2024.101180 -
Insects Feb 2024Mongolia, a country in central Asia, with its vast grassland areas represents a hotspot for Orthoptera diversity, especially for the Acrididae. For Mongolia, 128...
Mongolia, a country in central Asia, with its vast grassland areas represents a hotspot for Orthoptera diversity, especially for the Acrididae. For Mongolia, 128 Acrididae species have been documented so far, of which 41 belong to the subfamily Oedipodinae (band-winged grasshoppers). Yet, few studies concerning the distribution and diversity of Oedipodinae have been conducted in this country. Molecular genetic data is almost completely absent, despite its value for species identification and discovery. Even, the simplest and most used data, DNA barcodes, so far have not been generated for the local fauna. Therefore, we generated the first DNA barcode data for Mongolian band-winged grasshoppers and investigated the resolution of this marker for species delimitation. We were able to assemble 105 DNA barcode (COI) sequences of 35 Oedipodinae species from Mongolia and adjacent countries. Based on this data, we reconstructed maximum likelihood and Bayesian inference phylogenies. We, furthermore, conducted automatic barcode gap discovery and used the Poisson tree process (PTP) for species delimitation. Some resolution was achieved at the tribe and genus level, but all delimitation methods failed to differentiate species by using the COI region. This lack of resolution may have multiple possible reasons, which likely differ between taxa: the lack of resolution in the Bryodemini may be partially explained by their massive genomes, implying the potential presence of large numbers of pseudogenes, while within the Sphingonotini incomplete lineage sorting and incorrect taxonomy are more likely explanations for the lack of signal. Further studies based on a larger number of gene fragments, including nuclear DNA, are needed to distinguish the species also at the molecular level.
PubMed: 38392547
DOI: 10.3390/insects15020128 -
Insects Feb 2024Insect-resistant substances from plants are important natural resources that human beings can potentially develop and use to control pests. In this study, we explored...
Insect-resistant substances from plants are important natural resources that human beings can potentially develop and use to control pests. In this study, we explored the adverse effects of rutin and quercetin on grasshopper (), as well as the insect's physiological response to these substances in laboratory and field experiments. These two plant compounds exhibited toxic effects on , with quercetin showing a stronger toxicity, indicated by a lower survival, slower development, and higher induced gene expression and activities of UDP-glucuronosyltransferase, cytochrome P450s, superoxide dismutase, peroxidase and catalase, compared to rutin. These compounds, especially quercetin, have the potential to be developed as biopesticides to control grasshoppers.
PubMed: 38392514
DOI: 10.3390/insects15020095 -
Insects Jan 2024During the last century, well-known locust species, such as and , have produced outbreaks of varying degrees in the Balkans. The literature data on outbreaks in the...
During the last century, well-known locust species, such as and , 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 with altogether six mass occurrences, while second is and with three records, and in the third, place and sp., each with two mass occurrences having been reported. One of the most notable swarms is that of 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 swarm in Štikovo. The 2022 and 2023 reports were brief and muted, despite the affected agriculturists claiming significant damages.
PubMed: 38392502
DOI: 10.3390/insects15020082 -
Ecology and Evolution Feb 2024Species richness has been shown to decrease, and elevational range increase (the Rapoport effect), with elevation as a consequence of biotic and abiotic factors, but...
Species richness has been shown to decrease, and elevational range increase (the Rapoport effect), with elevation as a consequence of biotic and abiotic factors, but patterns are inconsistent across taxonomic groups. Despite being an important indicator taxon and a component of local communities, Orthoptera distributions at higher elevations in Europe remain unclear. We investigated the relationship of Orthoptera species richness and elevational range with elevation in the Pyrenees mountains, Europe. We conducted sweepnetting surveys supplemented by hand-sampling, at 28 sites stratified by elevation, across three study areas. Using generalised linear models, we found that species richness declined with elevation. Elevation was an important predictor of species richness, but sampling effort and vegetation structure (height and cover) also contributed to estimates of species richness. Using a nonlinear regression to model the elevational range of species over the elevational gradient, we did not observe a Rapoport effect, with elevational range peaking at mid-elevation instead. Smaller elevational ranges of species found at high elevations may be due to a combination of sampling over a restricted elevational range and the presence of specialist high-elevation species. We argue that our findings are useful for understanding species distributions with elevation at the interface between local and regional scales. Clarifying the biotic and abiotic predictors of species distribution is important for informing conservation efforts and predicting consequences of climate change.
PubMed: 38384823
DOI: 10.1002/ece3.10985 -
Pausing to swarm: locust intermittent motion is instrumental for swarming-related visual processing.Biology Letters Feb 2024Intermittent motion is prevalent in animal locomotion. Of special interest is the case of collective motion, in which social and environmental information must be...
Intermittent motion is prevalent in animal locomotion. Of special interest is the case of collective motion, in which social and environmental information must be processed in order to establish coordinated movement. We explored this nexus in locust, focusing on how intermittent motion interacts with swarming-related visual-based decision-making. Using a novel approach, we compared individual locust behaviour in response to continuously moving stimuli, with their response in semi-closed-loop conditions, in which the stimuli moved either in phase with the locust walking, or out of phase, i.e. only during the locust's pauses. Our findings clearly indicate the greater tendency of a locust to respond and 'join the swarming motion' when the visual stimuli were presented during its pauses. Hence, the current study strongly confirms previous indications of the dominant role of pauses in the collective motion-related decision-making of locusts. The presented insights contribute to a deeper general understanding of how intermittent motion contributes to group cohesion and coordination in animal swarms.
Topics: Animals; Grasshoppers; Locomotion; Behavior, Animal; Visual Perception; Motion
PubMed: 38378141
DOI: 10.1098/rsbl.2023.0468 -
Royal Society Open Science Feb 2024The biota of continents and islands are commonly considered to have a source-sink relationship, but small islands can harbour distinctive taxa. The distribution of four...
The biota of continents and islands are commonly considered to have a source-sink relationship, but small islands can harbour distinctive taxa. The distribution of four monotypic genera of Orthoptera on young subantarctic islands indicates a role for long-distance dispersal and extinction. Phylogenetic relationships were inferred from whole mtDNA genomes and nuclear sequences (45S cassette; four histones). We used a fossil and one palaeogeographic event to calibrate molecular clock analysis. We confirm that neither the Australian nor Aotearoa-New Zealand Rhaphidophoridae faunas are monophyletic. The radiation of Macropathinae may have begun in the late Jurassic, but trans-oceanic dispersal is required to explain the current distribution of some lineages within this subfamily. Dating the most recent common ancestor of seven island endemic species with their nearest mainland relative suggests that each existed long before their island home was available. Time estimates from our fossil-calibrated molecular clock analysis suggest several lineages have not been detected on mainland New Zealand, Australia, or elsewhere most probably due to their extinction, providing evidence that patterns of extinction, which are not consistently linked to range size or lineage age, confound biogeographic signal.
PubMed: 38356874
DOI: 10.1098/rsos.231118