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PeerJ 2023Whole mitochondrial genomes have been widely used in phylogenetic analysis, population genetics and biogeography studies. This study sequenced and characterized three...
Whole mitochondrial genomes have been widely used in phylogenetic analysis, population genetics and biogeography studies. This study sequenced and characterized three complete mitochondrial genomes (, , ) and determined their phylogenetic position in Acrididae. The length of the mitochondrial genomes ranged from 15,621-15,629 bp and composed of 13 PCGs, 2 rRNA, 22 tRNA genes and an AT control region. The arrangement and structure of the mitochondrial genomes were similar to those of other invertebrates. Comparative genomics revealed that the three mitochondrial genomes were highly conserved in terms of gene size, structure, and codon usage, all PCGs were purified selections with an ATN start codon and a TAN stop codon. All tRNAs could be folded into the typical clover-leaf structure, except tRNA Ser (AGN) that lacked a dihydrouridine (DHU) arm. Phylogenetic analysis based on 13 PCGs of 34 Acrididae species and seven outgroup species revealed that differences in the shape of antennae within the family Acrididae should be given less weight as a taxonomic character for higher-level classification. Moreover, the divergence time estimates indicates that in Gomphocerinae, the species with clubbed antennae were formed within the nearest 18 Mya, and is more ancient.
Topics: Animals; Grasshoppers; Phylogeny; Genome, Mitochondrial; Genome, Insect; RNA, Transfer
PubMed: 38111661
DOI: 10.7717/peerj.16550 -
ZooKeys 2023The genus Serville (Orthoptera: Tetrigidae) from China is reviewed. One species, Zheng & Ou, 2003 (China: Yunnan) is redescribed, and a new record of (Hancock, 1915)...
The genus Serville (Orthoptera: Tetrigidae) from China is reviewed. One species, Zheng & Ou, 2003 (China: Yunnan) is redescribed, and a new record of (Hancock, 1915) from China is given. An annotated identification key for Chinese species of the genus is provided. Mitochondrial genes of and were sequenced and annotated. The sizes of the two sequenced mitogenomes are 17,552 bp (), and 16,069 bp (), respectively. All of the PCGs started with the typical ATN (ATT, ATC or ATG) or TTG codon and most ended with complete TAA or TAG codon, with the exception of the ND5 gene, which terminated with an incomplete T. The mitochondrial genomes for these two recorded species are provided, and the constructed phylogenetic tree supports their morphological taxonomic classification. The topology of the phylogenetic tree showed that three species of were clustered into one branch and formed a monophyletic and a holophyletic group.
PubMed: 38074910
DOI: 10.3897/zookeys.1185.110148 -
Current Biology : CB Dec 2023Olfactory coding, from insects to humans, is canonically considered to involve considerable across-fiber coding already at the peripheral level, thereby allowing...
Olfactory coding, from insects to humans, is canonically considered to involve considerable across-fiber coding already at the peripheral level, thereby allowing recognition of vast numbers of odor compounds. We show that the migratory locust has evolved an alternative strategy built on highly specific odorant receptors feeding into a complex primary processing center in the brain. By collecting odors from food and different life stages of the locust, we identified 205 ecologically relevant odorants, which we used to deorphanize 48 locust olfactory receptors via ectopic expression in Drosophila. Contrary to the often broadly tuned olfactory receptors of other insects, almost all locust receptors were found to be narrowly tuned to one or very few ligands. Knocking out a single receptor using CRISPR abolished physiological and behavioral responses to the corresponding ligand. We conclude that the locust olfactory system, with most olfactory receptors being narrowly tuned, differs from the so-far described olfactory systems.
Topics: Animals; Humans; Odorants; Grasshoppers; Smell; Olfactory Receptor Neurons; Receptors, Odorant; Insecta
PubMed: 38070506
DOI: 10.1016/j.cub.2023.11.017 -
Scientific Reports Nov 2023The right choice of an oviposition site is a crucial task for oviparous species without maternal care. In contrast to well investigated biotic factors, e.g., larval food...
The right choice of an oviposition site is a crucial task for oviparous species without maternal care. In contrast to well investigated biotic factors, e.g., larval food preferences, parasitism, predation, and competition avoiding, abiotic factors affecting oviposition preferences in insects have been rarely investigated in comparative studies. To improve our current understanding of oviposition site selection in Orthoptera, we investigated the influence of substrate temperature and moisture on the oviposition behaviour of 14 temperate grasshopper species. Conspecific groups of adults were kept in arenas with simultaneous temperature and moisture gradients. For each ootheca produced during the experiment (n = 1192) we recorded its depth and local microclimatic conditions. Our results indicate that microclimatic oviposition preferences significantly differ among species, however, correlations between adult habitat preferences and microclimatic oviposition preferences were surprisingly weak. Even oligothermic species preferred substrate temperatures around 30 °C and some xerothermic species preferred higher humidity. The hypothesized tendency to place oothecae closer to the ground within grass tussocks under hot and dry conditions was confirmed. It is possible that species evaluate microclimatic conditions for oviposition in the context of occupied habitat, i.e., in a relative rather than absolute manner.
Topics: Female; Animals; Temperature; Humidity; Oviposition; Grasshoppers; Larva; Coleoptera
PubMed: 38036615
DOI: 10.1038/s41598-023-47789-z -
MycoKeys 2023Molecular phylogenetic and chemical analyses, and morphological characterization of collections of North American specimens support the description of two new species...
Molecular phylogenetic and chemical analyses, and morphological characterization of collections of North American specimens support the description of two new species and two new combinations for known species. is a pathogen of (Orthoptera) from the Pacific Northwest USA and is a pathogen of cicadae (Hemiptera) from the Southeast USA. New combinations are made for and based on morphological, ecological, and chemical study. A new cyclopeptide family proved indispensable in providing chemotaxonomic markers for resolving species in degraded herbarium specimens for which DNA sequencing is intractable. This approach enabled the critical linkage of a 142-year-old type specimen to a phylogenetic clade. The diversity of in North America and the utility of chemotaxonomy for the genus are discussed.
PubMed: 38025585
DOI: 10.3897/mycokeys.100.110959 -
Journal of Insect Science (Online) Nov 2023Insect gut bacteria play an essential role in the nutritional metabolism, growth, and development of insects. Grasshoppers (Orthoptera) are cellulose-rich plant-feeding...
Insect gut bacteria play an essential role in the nutritional metabolism, growth, and development of insects. Grasshoppers (Orthoptera) are cellulose-rich plant-feeding pests. Although the biological potential of grasshopper gut microorganisms to assist cellulose decomposition is well established, microbial resources for efficient degradation of cellulose biomass are still scarce and need to be developed. In this study, we used selective media to isolate cellulose-degrading bacteria from the intestines of Atractomorpha sinensis, Trilophidia annulata, Sphingonotus mongolicus, and Calliptamus abbreviatus. Phylogenetic analysis based on the maximum likelihood method using 16S rDNA sequencing sequences to identify bacteria revealed the isolation of 11 strains belonging to 3 genera, including Klebsiella, Aeromonas, and Bacillus. The degradability of the isolates to cellulose was then determined by the DNS colorimetric method, and the results showed that Bacillus had the highest degradation rate. The elucidation of microbial cellulose degradation capacity in grasshoppers not only contributes to the understanding of multiple plant-insect-microbe interactions, but also provides a valuable microbial resource for solving the biomass conversion of cellulose species problem.
Topics: Animals; Grasshoppers; Phylogeny; Cellulose; Bacteria; Biomass
PubMed: 38006418
DOI: 10.1093/jisesa/iead101 -
Insects Nov 2023In addition to feeding on plants, Mormon crickets Haldeman, 1852 predate on invertebrates, including one another, which effectively drives their migration. Carnivory...
In addition to feeding on plants, Mormon crickets Haldeman, 1852 predate on invertebrates, including one another, which effectively drives their migration. Carnivory derives from lack of dietary protein, with Mormon crickets deprived of protein having less phenoloxidase (PO) available to combat foreign invaders, such as fungal pathogens. Because Mormon crickets commonly occur with grasshoppers that feed on the same plants, we investigated interactions between grasshoppers and Mormon crickets, and hypothesized that if Mormon crickets are predatory on grasshoppers, grasshopper abundance would influence the protein available to Mormon crickets and their immunity. In a field setting, we varied densities of Mormon crickets (0, 10, or 20 per cage) and grasshoppers (0, 15, 30, or 45) in 68 1-m cages. After one month, we measured Mormon cricket dietary preferences and PO activity. As predicted, artificial diet consumption shifted away from protein as grasshopper density increased, and immunocompetence, as measured by PO activity, also increased with grasshopper availability. Although nitrogen availability in the vegetation decreased with increasing insect density, predation became an important source of protein for Mormon crickets that enhanced immunity. Grasshoppers can be an important source of dietary protein for Mormon crickets, with prey availability affecting Mormon cricket immunity to diseases.
PubMed: 37999067
DOI: 10.3390/insects14110868 -
Biology Oct 2023The yellow-spined bamboo locust (YSBL), Tsai, has historically had a significant impact on different bamboo varieties in East Asia and Southeast Asia. Since 2014, there...
The yellow-spined bamboo locust (YSBL), Tsai, has historically had a significant impact on different bamboo varieties in East Asia and Southeast Asia. Since 2014, there have been many outbreaks of YSBL populations in Laos, and YSBLs subsequently invaded Southwest China in 2020 and 2023. However, there was limited information about the damage to staple crops. Life table parameters and fitness parameters were assessed using wheat, rice, waxy maize, and sweet maize under three different temperatures (25 °C, 30 °C, and 35 °C) in the laboratory. The results indicated that the YSBLs feeding on wheat seedlings displayed a significantly higher survival rate, a shorter developmental time, and a higher adult emergence rate compared to YSBLs feeding on the other host species at 30 °C. The developmental durations of 1st and 3rd instar YSBLs on wheat (1st: 8.21 ± 0.35 d; 3rd: 6.32 ± 0.34 d) and rice (1st: 7.19 ± 0.23 d; 3rd: 9.00 ± 0.66 d) were significantly shorter than those of 1st and 3rd instar YSBLs on waxy maize (1st: 13.62 ± 1.22 d; 3rd: 13.67 ± 6.33 d) and sweet maize (1st: 16.00 ± 1.79 d; 3rd: 18.00 ± 3.49 d) at 30 °C. The body lengths of male and female YSBLs on wheat (male: 29.52 ± 0.40 mm, female: 34.97 ± 0.45 mm) and rice (male: 28.85 ± 0.68 mm, female: 34.66 ± 0.35 mm) were significantly longer than those observed when they were fed on sweet maize (male: 25.64 ± 1.60 mm, female: 21.93 ± 6.89 mm). There were only male adults obtained on waxy maize. The phenotypic characteristics of the YSBLs feeding on rice seedlings were very close to those of the YSBLs feeding on wheat seedlings. A relatively slower decline was observed in the survival rates of YSBL nymphs on wheat and rice compared to those on waxy maize and sweet maize at 25 °C, 30 °C, and 35 °C. In short, this study implied that YSBLs prefer wheat and rice. This study is the first report of direct damage caused by the YSBL to wheat in the laboratory, and its results could be useful in improving our understanding of the host preference of the YSBL and providing strategies for the management of this pest in field crops.
PubMed: 37997975
DOI: 10.3390/biology12111377 -
Molecular Biology and Evolution Dec 2023Many insects carry an ancient X chromosome-the Drosophila Muller element F-that likely predates their origin. Interestingly, the X has undergone turnover in multiple fly...
Many insects carry an ancient X chromosome-the Drosophila Muller element F-that likely predates their origin. Interestingly, the X has undergone turnover in multiple fly species (Diptera) after being conserved for more than 450 My. The long evolutionary distance between Diptera and other sequenced insect clades makes it difficult to infer what could have contributed to this sudden increase in rate of turnover. Here, we produce the first genome and transcriptome of a long overlooked sister-order to Diptera: Mecoptera. We compare the scorpionfly Panorpa cognata X-chromosome gene content, expression, and structure to that of several dipteran species as well as more distantly related insect orders (Orthoptera and Blattodea). We find high conservation of gene content between the mecopteran X and the dipteran Muller F element, as well as several shared biological features, such as the presence of dosage compensation and a low amount of genetic diversity, consistent with a low recombination rate. However, the 2 homologous X chromosomes differ strikingly in their size and number of genes they carry. Our results therefore support a common ancestry of the mecopteran and ancestral dipteran X chromosomes, and suggest that Muller element F shrank in size and gene content after the split of Diptera and Mecoptera, which may have contributed to its turnover in dipteran insects.
Topics: Animals; Humans; X Chromosome; Insecta; Drosophila; Chromosomes, Human, X; Biological Evolution; Dosage Compensation, Genetic
PubMed: 37988296
DOI: 10.1093/molbev/msad245 -
Current Biology : CB Dec 2023Hearing has evolved independently many times in the animal kingdom and is prominent in various insects and vertebrates for conspecific communication and predator...
Hearing has evolved independently many times in the animal kingdom and is prominent in various insects and vertebrates for conspecific communication and predator detection. Among insects, katydid (Orthoptera: Tettigoniidae) ears are unique, as they have evolved outer, middle, and inner ear components, analogous in their biophysical principles to the mammalian ear. The katydid ear consists of two paired tympana located in each foreleg. These tympana receive sound externally on the tympanum surface (usually via pinnae) or internally via an ear canal (EC). The EC functions to capture conspecific calls and low frequencies, while the pinnae passively amplify higher-frequency ultrasounds including bat echolocation. Together, these outer ear components provide enhanced hearing sensitivity across a dynamic range of over 100 kHz. However, despite a growing understanding of the biophysics and function of the katydid ear, its precise emergence and evolutionary history remains elusive. Here, using microcomputed tomography (μCT) scanning, we recovered geometries of the outer ear components and wings of an exceptionally well-preserved katydid fossilized in Baltic amber (∼44 million years [Ma]). Using numerical and theoretical modeling of the wings, we show that this species was communicating at a peak frequency of 31.62 (± 2.27) kHz, and we demonstrate that the ear was biophysically tuned to this signal and to providing hearing at higher-frequency ultrasounds (>80 kHz), likely for enhanced predator detection. The results indicate that the evolution of the unique ear of the katydid, with its broadband ultrasonic sensitivity and analogous biophysical properties to the ears of mammals, emerged in the Eocene.
Topics: Animals; Echolocation; Chiroptera; X-Ray Microtomography; Hearing; Mammals; Orthoptera
PubMed: 37963458
DOI: 10.1016/j.cub.2023.10.040