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Biology Letters May 2022The degradation of natural habitats is causing ongoing homogenization of biological communities and declines in terrestrial insect biodiversity, particularly in...
The degradation of natural habitats is causing ongoing homogenization of biological communities and declines in terrestrial insect biodiversity, particularly in agricultural landscapes. Orthoptera are focal species of nature conservation and experienced significant diversity losses over the past decades. However, the causes underlying these changes are not yet fully understood. We analysed changes in Orthoptera assemblages surveyed in 1988, 2004 and 2019 on 198 plots distributed across four major grassland types in Central Europe. We demonstrated compositional differences in Orthoptera assemblages found in wet, dry and mesic grasslands, as well as ruderal habitats decreased, indicating biotic homogenization. However, mean α-diversity of Orthoptera assemblages increased over the study period. We detected increasing numbers of species with preferences for higher temperatures in mesic and wet grasslands. By analysing the temperature, moisture and vegetation preferences of Orthoptera, we found that additive homogenization was driven by a loss of species adapted to extremely dry and nitrogen-poor habitats and a parallel spread of species preferring warmer macroclimates.
Topics: Animals; Biodiversity; Ecosystem; Grassland; Orthoptera; Temperature
PubMed: 35611582
DOI: 10.1098/rsbl.2022.0055 -
Journal of Insect Science (Online) Jan 2022To fully understand microplastics' impact on soil ecosystems, one must recognize soil organisms as not just passively enduring their negative effects, but potentially...
To fully understand microplastics' impact on soil ecosystems, one must recognize soil organisms as not just passively enduring their negative effects, but potentially contributing to microplastics' formation, distribution, and dynamics in soil. We investigated the ability of four soil invertebrates, the cricket Acheta domesticus L. (Orthoptera: Gryllidae), the isopod Oniscus asellus L. (Isopoda: Oniscidae), larvae of the beetle Zophobas morio Fabricius (Coleoptera: Tenebrionidae), and the snail Cornu aspersum Müller (Stylommatophora: Helicidae) to fragment macroscopic pieces of weathered or pristine polystyrene (PS) foam. We placed invertebrates into arenas with single PS foam pieces for 24 h, then collected and assessed the microplastic content of each invertebrate's fecal material, its cadaver, and the sand substrate of its arena via hydrogen peroxide digestion, filtration, and fluorescent staining. All taxa excreted PS particles, though snails only to a tiny extent. Beetle larvae produced significantly more microplastics than snails, and crickets and isopods fragmented the weathered PS foam pieces more than the pristine pieces, which they left untouched. A follow-up experiment with pristine PS foam assessed the effect of different treatments mimicking exposure to the elements on fragmentation by isopods. PS foam pieces soaked in a soil suspension were significantly more fragmented than untreated pieces or pieces exposed to UV light alone. These findings indicate that soil invertebrates may represent a source of microplastics to the environment in places polluted with PS foam trash, and that the condition of macroplastic debris likely affects its palatability to these organisms.
Topics: Animals; Coleoptera; Ecosystem; Invertebrates; Isoptera; Microplastics; Orthoptera; Polystyrenes; Snails; Soil; Soil Pollutants
PubMed: 35157762
DOI: 10.1093/jisesa/ieac005 -
Annual Review of Entomology Jan 2024Locusts are grasshoppers that can migrate en masse and devastate food security. Plant nutrient content is a key variable influencing population dynamics, but the... (Review)
Review
Locusts are grasshoppers that can migrate en masse and devastate food security. Plant nutrient content is a key variable influencing population dynamics, but the relationship is not straightforward. For an herbivore, plant quality depends not only on the balance of nutrients and antinutrients in plant tissues, which is influenced by land use and climate change, but also on the nutritional state and demands of the herbivore, as well as its capacity to extract nutrients from host plants. In contrast to the concept of a positive relationship between nitrogen or protein concentration and herbivore performance, a five-decade review of lab and field studies indicates that equating plant N to plant quality is misleading because grasshoppers respond negatively or neutrally to increasing plant N just as often as they respond positively. For locusts specifically, low-N environments are actually beneficial because they supply high energy rates that support migration. Therefore, intensive land use, such as continuous grazing or cropping, and elevated ambient CO levels that decrease the protein:carbohydrate ratios of plants are predicted to broadly promote locust outbreaks.
Topics: Animals; Grasshoppers; Ecosystem; Plants; Herbivory; Nutrients
PubMed: 38270985
DOI: 10.1146/annurev-ento-120220-110415 -
PloS One 2021Tonkinacris is a small group in Acrididae. While a few species were occasionally sampled in some previous molecular studies, there is no revisionary research devoted to...
Tonkinacris is a small group in Acrididae. While a few species were occasionally sampled in some previous molecular studies, there is no revisionary research devoted to the genus. In this study, we explored the phylogeny of and the relationships among Chinese species of the genus Tonkinacris using the mitochondrial COI barcode and the complete sequences of ITS1 and ITS2 of the nuclear ribosomal DNA. The phylogeny was reconstructed in maximum likelihood and Bayesian inference frameworks, respectively. The overlap range between intraspecific variation and interspecific divergence was assessed via K2P distances. Species boundaries were delimitated using phylogenetic species concept, NJ tree, K2P distance, the statistical parsimony network as well as the GMYC model. The results demonstrate that the Chinese Tonkinacris species is a monophyletic group and the phylogenetic relationship among them is (T. sinensis, (T. meridionalis, (T. decoratus, T. damingshanus))). While T. sinensis, T. meridionalis and T. decoratus were confirmed being good independent species strongly supported by both morphological and molecular evidences, the validity of T. damingshanus was not perfectly supported by molecular evidence in this study.
Topics: Animals; Bayes Theorem; China; Genetic Variation; Grasshoppers; Phylogeny
PubMed: 33848300
DOI: 10.1371/journal.pone.0249431 -
ELife Mar 2020Inhibitory neurons play critical roles in regulating and shaping olfactory responses in vertebrates and invertebrates. In insects, these roles are performed by...
Inhibitory neurons play critical roles in regulating and shaping olfactory responses in vertebrates and invertebrates. In insects, these roles are performed by relatively few neurons, which can be interrogated efficiently, revealing fundamental principles of olfactory coding. Here, with electrophysiological recordings from the locust and a large-scale biophysical model, we analyzed the properties and functions of GGN, a unique giant GABAergic neuron that plays a central role in structuring olfactory codes in the locust mushroom body. Our simulations suggest that depolarizing GGN at its input branch can globally inhibit KCs several hundred microns away. Our in vivorecordings show that GGN responds to odors with complex temporal patterns of depolarization and hyperpolarization that can vary with odors and across animals, leading our model to predict the existence of a yet-undiscovered olfactory pathway. Our analysis reveals basic new features of GGN and the olfactory network surrounding it.
Topics: Animals; Computer Simulation; Feedback, Physiological; Female; Grasshoppers; Male; Models, Biological; Neurons; Smell
PubMed: 32163034
DOI: 10.7554/eLife.53281 -
Genome Biology and Evolution Jan 2022The pygmy mole cricket Xya riparia (Orthoptera: Tridactyloidea) is rarely studied or widely known. Some species of pygmy mole crickets, however, not only have a...
The pygmy mole cricket Xya riparia (Orthoptera: Tridactyloidea) is rarely studied or widely known. Some species of pygmy mole crickets, however, not only have a potential ecological value but are also important in the study of the evolution of the orthopteran genome and its phylogenetic relationships. The genome resources of pygmy crickets are limited and there are currently no publications referencing this species' genome. In this study, we assembled a reference genome of X. riparia at the chromosomal level using nanopore sequencing and Hi-C technology. An X. riparia genome of 1.67 Gb was successfully assembled from 164.01 Gb of nanopore sequencing data. The genome assembly showed a completeness of 98.97% benchmarking universal single-copy orthologs with a contig N50 of 4.18 Mb and the longest contig being 18.84 Mb. The contigs were clustered, ordered, and correctly oriented on six pseuchromosomes, which covered 95.63% of the genome assembly through Hi-C data with a scaffold N50 of 319.1 Mb and the longest scaffold being 397.8 Mb. Repeat sequences accounted for 42.88% of the whole-genome assembly. A total of 60,847 noncoding RNAs were detected. Moreover, 16,468 (87.91%) of the genes were functionally annotated. As this is the first high-quality reference genome of X. riparia at the chromosomal level, it will undoubtedly serve as a valuable resource for ecological, biological, and genetic research on pygmy mole crickets as well as for general research on Orthoptera's genome evolution and phylogenetic relationships.
Topics: Animals; Chromosomes; Genome; Gryllidae; Molecular Sequence Annotation; Phylogeny
PubMed: 34999819
DOI: 10.1093/gbe/evac001 -
Philosophical Transactions of the Royal... Oct 2018Much research has been devoted to study evolution of local adaptations by natural selection, and to explore the roles of neutral processes and developmental plasticity... (Review)
Review
Much research has been devoted to study evolution of local adaptations by natural selection, and to explore the roles of neutral processes and developmental plasticity for patterns of diversity among individuals, populations and species. Some aspects, such as evolution of adaptive variation in phenotypic traits in stable environments, and the role of plasticity in predictable changing environments, are well understood. Other aspects, such as the role of sex differences for evolution in spatially heterogeneous and temporally changing environments and dynamic fitness landscapes, remain elusive. An increased understanding of evolution requires that sex differences in development, physiology, morphology, life-history and behaviours are more broadly considered. Studies of selection should take into consideration that the relationships linking phenotypes to fitness may vary not only according to environmental conditions but also differ between males and females. Such opposing selection, sex-by-environment interaction effects of selection and sex-specific developmental plasticity can have consequences for population differentiation, local adaptations and for the dynamics of polymorphisms. Integrating sex differences in analytical frameworks and population comparisons can therefore illuminate neglected evolutionary drivers and reconcile unexpected patterns. Here, I illustrate these issues using empirical examples from over 20 years of research on colour polymorphic and pygmy grasshoppers, and summarize findings from observational field studies, manipulation experiments, common garden breeding experiments and population genetics studies.This article is part of the theme issue 'Linking local adaptation with the evolution of sex differences'.
Topics: Adaptation, Physiological; Animals; Biological Evolution; Body Size; Color; Female; Genetic Heterogeneity; Genetic Variation; Grasshoppers; Male; Phenotype; Pigmentation; Polymorphism, Genetic; Selection, Genetic; Sex Characteristics
PubMed: 30150227
DOI: 10.1098/rstb.2017.0429 -
PloS One 2018The morphology and ultrastructure of the midgut of Gampsocleis gratiosa (Orthoptera: Tettigoniidae) was examined by light and electron microscopy. The midgut consists of...
The morphology and ultrastructure of the midgut of Gampsocleis gratiosa (Orthoptera: Tettigoniidae) was examined by light and electron microscopy. The midgut consists of two bulbous gastric caeca and a tubular ventriculus. The general organization of the gastric caeca is similar to that of the ventriculus. They are composed of a peritrophic membrane, an epithelium, a basal lamina and muscle layer from the inside to outside. Three types of cells were identified: regenerative, principal, and endocrine. Regenerative cells occur in groups (called nidi) at the base of principal cells. Principal cells grow from regenerative cells. Rare endocrine cells are scattered throughout the epithelium. Principal cells exhibit intense secretory activity, and regional differences in their ultrastructure were observed along the entire midgut. The microvilli are longer than those in any other region in the posterior region of the midgut. Lysosomes, multivesicular bodies (MVBs), autophagosomes, abundant Golgi apparatuses and lipid droplets primarily occur in the gastric caeca. Three pathways of secretion (merocrine, apocrine and holocrine) occur within the midgut epithelium, and a distinctive type of apocrine bleb was found in the gastric caeca. Therefore, these gastric caeca may be evolving toward a special type of gland.
Topics: Animals; Digestive System; Orthoptera
PubMed: 29985965
DOI: 10.1371/journal.pone.0200405 -
F1000Research 2020: At the time of publication, the most devastating desert locust crisis in decades is affecting East Africa, the Arabian Peninsula and South-West Asia. The situation is...
: At the time of publication, the most devastating desert locust crisis in decades is affecting East Africa, the Arabian Peninsula and South-West Asia. The situation is extremely alarming in East Africa, where Kenya, Ethiopia and Somalia face an unprecedented threat to food security and livelihoods. Most of the time, however, locusts do not occur in swarms, but live as relatively harmless solitary insects. The phenotypically distinct solitarious and gregarious locust phases differ markedly in many aspects of behaviour, physiology and morphology, making them an excellent model to study how environmental factors shape behaviour and development. A better understanding of the extreme phenotypic plasticity in desert locusts will offer new, more environmentally sustainable ways of fighting devastating swarms. : High molecular weight DNA derived from two adult males was used for Mate Pair and Paired End Illumina sequencing and PacBio sequencing. A reliable reference genome of was assembled using the ABySS pipeline, scaffolding was improved using LINKS. : In total, 1,316 Gb Illumina reads and 112 Gb PacBio reads were produced and assembled. The resulting draft genome consists of 8,817,834,205 bp organised in 955,015 scaffolds with an N50 of 157,705 bp, making the desert locust genome the largest insect genome sequenced and assembled to date. In total, 18,815 protein-encoding genes are predicted in the desert locust genome, of which 13,646 (72.53%) obtained at least one functional assignment based on similarity to known proteins. : The desert locust genome data will contribute greatly to studies of phenotypic plasticity, physiology, neurobiology, molecular ecology, evolutionary genetics and comparative genomics, and will promote the desert locust's use as a model system. The data will also facilitate the development of novel, more sustainable strategies for preventing or combating swarms of these infamous insects.
Topics: Animals; Base Sequence; Genome, Insect; Grasshoppers; High-Throughput Nucleotide Sequencing; Kenya; Male
PubMed: 33163158
DOI: 10.12688/f1000research.25148.2 -
Journal of Insect Science (Online) Sep 2020The present study deals with the taxonomical analysis of the edible insects commercialized in the state of Morelos, Mexico. We have recorded two species under the order...
The present study deals with the taxonomical analysis of the edible insects commercialized in the state of Morelos, Mexico. We have recorded two species under the order Orthoptera and four species under Hemiptera-Heteroptera. Our work revealed that grasshoppers and small hemipterans known as 'jumiles' are the two main insects sold in the markets of the state of Morelos. We also discuss insects' prices and their economic importance for the livelihood improvement of the local people connected to the edible insect trade.
Topics: Animals; Commerce; Diet; Edible Insects; Grasshoppers; Hemiptera; Humans; Indigenous Peoples; Mexico
PubMed: 33064131
DOI: 10.1093/jisesa/ieaa106