Ecology and Evolution of Communication in Social Insects.

Insect life strategies comprise all levels of sociality from solitary to eusocial, in which individuals form persistent groups and divide labor. With increasing social complexity, the need to communicate a greater diversity of messages arose to coordinate division of labor, group cohesion, and concerted actions. Here we summarize the knowledge on prominent messages in social insects that inform about reproduction, group membership, resource locations, and threats and discuss potential evolutionary trajectories of each message in the context of social complexity.

Disproportionate declines of formerly abundant species underlie insect loss.

Studies have reported widespread declines in terrestrial insect abundances in recent years1-4, but trends in other biodiversity metrics are less clear-cut5-7. Here we examined long-term trends in 923 terrestrial insect assemblages monitored in 106 studies, and found concomitant declines in abundance and species richness. For studies that were resolved to species level (551 sites in 57 studies), we observed a decline in the number of initially abundant species through time, but not in the number of very rare species. At the population level, we found that species that were most abundant at the start of the time series showed the strongest average declines (corrected for regression-to-the-mean effects). Rarer species were, on average, also declining, but these were offset by increases of other species. Our results suggest that the observed decreases in total insect abundance2 can mostly be explained by widespread declines of formerly abundant species. This counters the common narrative that biodiversity loss is mostly characterized by declines of rare species8,9. Although our results suggest that fundamental changes are occurring in insect assemblages, it is important to recognize that they represent only trends from those locations for which sufficient long-term data are available. Nevertheless, given the importance of abundant species in ecosystems10, their general declines are likely to have broad repercussions for food webs and ecosystem functioning.

Bridging two insect flight modes in evolution, physiology and robophysics.

Since taking flight, insects have undergone repeated evolutionary transitions between two seemingly distinct flight modes1-3. Some insects neurally activate their muscles synchronously with each wingstroke. However, many insects have achieved wingbeat frequencies beyond the speed limit of typical neuromuscular systems by evolving flight muscles that are asynchronous with neural activation and activate in response to mechanical stretch2-8. These modes reflect the two fundamental ways of generating rhythmic movement: time-periodic forcing versus emergent oscillations from self-excitation8-10. How repeated evolutionary transitions have occurred and what governs the switching between these distinct modes remain unknown. Here we find that, despite widespread asynchronous actuation in insects across the phylogeny3,6, asynchrony probably evolved only once at the order level, with many reversions to the ancestral, synchronous mode. A synchronous moth species, evolved from an asynchronous ancestor, still preserves the stretch-activated muscle physiology. Numerical and robophysical analyses of a unified biophysical framework reveal that rather than a dichotomy, these two modes are two regimes of the same dynamics. Insects can transition between flight modes across a bridge in physiological parameter space. Finally, we integrate these two actuation modes into an insect-scale robot11-13 that enables transitions between modes and unlocks a new self-excited wingstroke strategy for engineered flight. Together, this framework accounts for repeated transitions in insect flight evolution and shows how flight modes can flip with changes in physiological parameters.

Competition for pollinators destabilizes plant coexistence.

Mounting concern over the global decline of pollinators has fuelled calls for investigating their role in maintaining plant diversity1,2. Theory predicts that competition for pollinators can stabilize interactions between plant species by providing opportunities for niche differentiation3, while at the same time can drive competitive imbalances that favour exclusion4. Here we empirically tested these contrasting effects by manipulating competition for pollinators in a way that predicts its long-term implications for plant coexistence. We subjected annual plant individuals situated across experimentally imposed gradients in neighbour density to either ambient insect pollination or a pollen supplementation treatment alleviating competition for pollinators. The vital rates of these individuals informed plant population dynamic models predicting the key theoretical metrics of species coexistence. Competition for pollinators generally destabilized the interactions between plant species, reducing the proportion of pairs expected to coexist. Interactions with pollinators also influenced the competitive imbalances between plant species, effects that are expected to strengthen with pollinator decline, potentially disrupting plant coexistence. Indeed, results from an experiment simulating pollinator decline showed that plant species experiencing greater reductions in floral visitation also suffered greater declines in population growth rate. Our results reveal that competition for pollinators may weaken plant coexistence by destabilizing interactions and contributing to competitive imbalances, information critical for interpreting the impacts of pollinator decline.

Chewing through challenges: Exploring the evolutionary pathways to wood-feeding in insects.

Decaying wood, while an abundant and stable resource, presents considerable nutritional challenges due to its structural rigidity, chemical recalcitrance, and low nitrogen content. Despite these challenges, certain insect lineages have successfully evolved saproxylophagy (consuming and deriving sustenance from decaying wood), impacting nutrient recycling in ecosystems and carbon sequestration dynamics. This study explores the uneven phylogenetic distribution of saproxylophagy across insects and delves into the evolutionary origins of this trait in disparate insect orders. Employing a comprehensive analysis of gut microbiome data, from both saproxylophagous insects and their non-saproxylophagous relatives, including new data from unexplored wood-feeding insects, this Hypothesis paper discusses the broader phylogenetic context and potential adaptations necessary for this dietary specialization. The study proposes the "Detritivore-First Hypothesis," suggesting an evolutionary pathway to saproxylophagy through detritivory, and highlights the critical role of symbiotic gut microbiomes in the digestion of decaying wood.

Cryo-EM structure of the insect olfactory receptor Orco.

The olfactory system must recognize and discriminate amongst an enormous variety of chemicals in the environment. To contend with such diversity, insects have evolved a family of odorant-gated ion channels comprised of a highly conserved co-receptor (Orco) and a divergent odorant receptor (OR) that confers chemical specificity. Here, we present the single-particle cryo-electron microscopy structure of an Orco homomer from the parasitic fig wasp Apocrypta bakeri at 3.5 Å resolution, providing structural insight into this receptor family. Orco possesses a novel channel architecture, with four subunits symmetrically arranged around a central pore that diverges into four lateral conduits that open to the cytosol. The Orco tetramer has few inter-subunit interactions within the membrane and is bound together by a small cytoplasmic anchor domain. The minimal sequence conservation among ORs maps largely to the pore and anchor domain, shedding light on how the architecture of this receptor family accommodates its remarkable sequence diversity and facilitates the evolution of odour tuning.

InsectBase 2.0: a comprehensive gene resource for insects.

Insects are the largest group of animals on the planet and have a huge impact on human life by providing resources, transmitting diseases, and damaging agricultural crop production. Recently, a large amount of insect genome and gene data has been generated. A comprehensive database is highly desirable for managing, sharing, and mining these resources. Here, we present an updated database, InsectBase 2.0 (http://v2.insect-genome.com/), covering 815 insect genomes, 25 805 transcriptomes and >16 million genes, including 15 045 111 coding sequences, 3 436 022 3'UTRs, 4 345 664 5'UTRs, 112 162 miRNAs and 1 293 430 lncRNAs. In addition, we used an in-house standard pipeline to annotate 1 434 653 genes belonging to 164 gene families; 215 986 potential horizontally transferred genes; and 419 KEGG pathways. Web services such as BLAST, JBrowse2 and Synteny Viewer are provided for searching and visualization. InsectBase 2.0 serves as a valuable platform for entomologists and researchers in the related communities of animal evolution and invertebrate comparative genomics.

PHI-base in 2022: a multi-species phenotype database for Pathogen-Host Interactions.

Since 2005, the Pathogen-Host Interactions Database (PHI-base) has manually curated experimentally verified pathogenicity, virulence and effector genes from fungal, bacterial and protist pathogens, which infect animal, plant, fish, insect and/or fungal hosts. PHI-base (www.phi-base.org) is devoted to the identification and presentation of phenotype information on pathogenicity and effector genes and their host interactions. Specific gene alterations that did not alter the in host interaction phenotype are also presented. PHI-base is invaluable for comparative analyses and for the discovery of candidate targets in medically and agronomically important species for intervention. Version 4.12 (September 2021) contains 4387 references, and provides information on 8411 genes from 279 pathogens, tested on 228 hosts in 18, 190 interactions. This provides a 24% increase in gene content since Version 4.8 (September 2019). Bacterial and fungal pathogens represent the majority of the interaction data, with a 54:46 split of entries, whilst protists, protozoa, nematodes and insects represent 3.6% of entries. Host species consist of approximately 54% plants and 46% others of medical, veterinary and/or environmental importance. PHI-base data is disseminated to UniProtKB, FungiDB and Ensembl Genomes. PHI-base will migrate to a new gene-centric version (version 5.0) in early 2022. This major development is briefly described.

VEuPathDB: the eukaryotic pathogen, vector and host bioinformatics resource center.

The Eukaryotic Pathogen, Vector and Host Informatics Resource (VEuPathDB, https://veupathdb.org) represents the 2019 merger of VectorBase with the EuPathDB projects. As a Bioinformatics Resource Center funded by the National Institutes of Health, with additional support from the Welllcome Trust, VEuPathDB supports >500 organisms comprising invertebrate vectors, eukaryotic pathogens (protists and fungi) and relevant free-living or non-pathogenic species or hosts. Designed to empower researchers with access to Omics data and bioinformatic analyses, VEuPathDB projects integrate >1700 pre-analysed datasets (and associated metadata) with advanced search capabilities, visualizations, and analysis tools in a graphic interface. Diverse data types are analysed with standardized workflows including an in-house OrthoMCL algorithm for predicting orthology. Comparisons are easily made across datasets, data types and organisms in this unique data mining platform. A new site-wide search facilitates access for both experienced and novice users. Upgraded infrastructure and workflows support numerous updates to the web interface, tools, searches and strategies, and Galaxy workspace where users can privately analyse their own data. Forthcoming upgrades include cloud-ready application architecture, expanded support for the Galaxy workspace, tools for interrogating host-pathogen interactions, and improved interactions with affiliated databases (ClinEpiDB, MicrobiomeDB) and other scientific resources, and increased interoperability with the Bacterial & Viral BRC.

Helicopsyche (Feropsyche) Johanson, 1998 (Trichoptera) from Northeastern Mata Atlântica Freshwater ecoregion: integrating taxonomy and niche modeling.

The Northeastern Mata Atlântica Freshwater ecoregion (NMAF) is part of the 25 worlds biodiversity hotspots. It comprises the Central Atlantic Forest Ecological Corridor and Chapada Diamantina Complex (in part), including high rates of endemism in coastal freshwater ecosystems. However, estimates indicate a high population decline in Freshwater ecosystems. Trichoptera are the most affected insect order, with average extinction rates of ~9% and many unknown species (e.g., estimates are around 50% in Brazil and Ecuador). This crisis can be aggravated by gaps in the knowledge of species (Linnean shortfall) and their distribution (Wallacean shortfall), caused mainly by a lack of investment in extensive fauna inventories and human resources related to systematics. Thus, to face these shortfalls in NMAF, we describe four new species of. H. (Feropsyche) and provide new distribution records. In addition, we perform niche modeling based on the species distributions of the group to identify areas with high environmental suitability to direct biodiversity research efforts on NMAF, a highly endemic and underexplored ecoregion. We increased the number of known species of NMAF from seven to 16 species. The niche modeling pointed to two areas as priorities to guide the strategies to reduce shortfalls in the NMAF.

The importance of Brazilian Conservation Units for the diversity of gall-inducing insects: a study on gall-inducing insect richness in the Chapada Diamantina National Park, state of Bahia, Brazil.

Conservation Units (CUs) tend to have a high richness of herbivorous insects, including gall-inducing insects. Despite this, gall surveys carried out in these environments are punctual and some units have never had their galls investigated, such as the Chapada Diamantina National Park, Bahia (Chapada Diamantina Parna). Aiming to reduce this gap and contribute to future studies in CUs, this study aimed to survey the galls of the Chapada Diamantina Parna, Lençóis, as well as to investigate trends in research on galls in CUs in Brazil. For that, collections were carried out on monthly trips for one year. Published gall surveys were compiled. A total of 107 morphotypes induced in 88 host species were recorded. Most galls are formed in leaves, globoid in shape, green in color, and induced by Cecidomyiidae. This park has a relatively high richness of galls compared to other CUs, demonstrating its importance in the conservation of gall-inducing insects. The results also revealed that the number of surveys has been increasing over the years and that the Southeast concentrates the largest number of studies, a region that also gathers the largest number of specialists, demonstrating a geographic bias in the data.

Worldwide revision of synanthropic silverfish (Insecta: Zygentoma: Lepismatidae) combining morphological and molecular data.

Synanthropic silverfish are the best-known and most widely distributed insects of the order Zygentoma. However, there is a great gap in the knowledge and confusion about the geographic distribution and the diagnostic characteristics that allow their identification. In this work, we provide an exhaustive and deep analysis of the most common 9 synanthropic silverfish of the world, combining previously published and newly derived morphological and molecular data. Updated descriptions of Ctenolepisma calvum (Ritter, 1910) and Ctenolepisma (Sceletolepisma) villosum (Fabricius, 1775) are included, and morphological remarks, illustrations, and photographs of the remaining synanthropic species are provided to clarify their diagnosis and differentiation among them and from other free-living species. In addition, Ctenolepisma targionii (Grassi and Rovelli, 1889) is synonymized with C. villosum. A molecular phylogeny is presented based on the COI sequences of all the synanthropic species deposited in BOLD and GenBank, with 15 new sequences provided by this study. This has allowed us to detect and correct a series of identification errors based on the lack of morphological knowledge of several species. Moreover, 2 different lineages of Ctenolepisma longicaudatumEscherich, 1905 have also been detected. To help future studies, we also provide a taxonomic interpretation guide for the most important diagnostic characters of the order Zygentoma, as well as an identification key for all the Synanthropic studied species. Finally, an approximation of the global distribution of synanthropic silverfish is discussed. Several new records indicate that the expansion of these species, generally associated with the transport of goods and people, is still far from over.

Highly accurate long reads are crucial for realizing the potential of biodiversity genomics.

BACKGROUND: Generating the most contiguous, accurate genome assemblies given available sequencing technologies is a long-standing challenge in genome science. With the rise of long-read sequencing, assembly challenges have shifted from merely increasing contiguity to correctly assembling complex, repetitive regions of interest, ideally in a phased manner. At present, researchers largely choose between two types of long read data: longer, but less accurate sequences, or highly accurate, but shorter reads (i.e., >Q20 or 99% accurate). To better understand how these types of long-read data as well as scale of data (i.e., mean length and sequencing depth) influence genome assembly outcomes, we compared genome assemblies for a caddisfly, Hesperophylax magnus, generated with longer, but less accurate, Oxford Nanopore (ONT) R9.4.1 and highly accurate PacBio HiFi (HiFi) data. Next, we expanded this comparison to consider the influence of highly accurate long-read sequence data on genome assemblies across 6750 plant and animal genomes. For this broader comparison, we used HiFi data as a surrogate for highly accurate long-reads broadly as we could identify when they were used from GenBank metadata. RESULTS: HiFi reads outperformed ONT reads in all assembly metrics tested for the caddisfly data set and allowed for accurate assembly of the repetitive ~ 20 Kb H-fibroin gene. Across plants and animals, genome assemblies that incorporated HiFi reads were also more contiguous. For plants, the average HiFi assembly was 501% more contiguous (mean contig N50 = 20.5 Mb) than those generated with any other long-read data (mean contig N50 = 4.1 Mb). For animals, HiFi assemblies were 226% more contiguous (mean contig N50 = 20.9 Mb) versus other long-read assemblies (mean contig N50 = 9.3 Mb). In plants, we also found limited evidence that HiFi may offer a unique solution for overcoming genomic complexity that scales with assembly size. CONCLUSIONS: Highly accurate long-reads generated with HiFi or analogous technologies represent a key tool for maximizing genome assembly quality for a wide swath of plants and animals. This finding is particularly important when resources only allow for one type of sequencing data to be generated. Ultimately, to realize the promise of biodiversity genomics, we call for greater uptake of highly accurate long-reads in future studies.

Millipede genomes reveal unique adaptations during myriapod evolution.

The Myriapoda, composed of millipedes and centipedes, is a fascinating but poorly understood branch of life, including species with a highly unusual body plan and a range of unique adaptations to their environment. Here, we sequenced and assembled 2 chromosomal-level genomes of the millipedes Helicorthomorpha holstii (assembly size = 182 Mb; shortest scaffold/contig length needed to cover 50% of the genome [N50] = 18.11 Mb mainly on 8 pseudomolecules) and Trigoniulus corallinus (assembly size = 449 Mb, N50 = 26.78 Mb mainly on 17 pseudomolecules). Unique genomic features, patterns of gene regulation, and defence systems in millipedes, not observed in other arthropods, are revealed. Both repeat content and intron size are major contributors to the observed differences in millipede genome size. Tight Hox and the first loose ecdysozoan ParaHox homeobox clusters are identified, and a myriapod-specific genomic rearrangement including Hox3 is also observed. The Argonaute (AGO) proteins for loading small RNAs are duplicated in both millipedes, but unlike in insects, an AGO duplicate has become a pseudogene. Evidence of post-transcriptional modification in small RNAs-including species-specific microRNA arm switching-providing differential gene regulation is also obtained. Millipedes possesses a unique ozadene defensive gland unlike the venomous forcipules found in centipedes. We identify sets of genes associated with the ozadene that play roles in chemical defence as well as antimicrobial activity. Macro-synteny analyses revealed highly conserved genomic blocks between the 2 millipedes and deuterostomes. Collectively, our analyses of millipede genomes reveal that a series of unique adaptations have occurred in this major lineage of arthropod diversity. The 2 high-quality millipede genomes provided here shed new light on the conserved and lineage-specific features of millipedes and centipedes. These findings demonstrate the importance of the consideration of both centipede and millipede genomes-and in particular the reconstruction of the myriapod ancestral situation-for future research to improve understanding of arthropod evolution, and animal evolutionary genomics more widely.

Genomics Reveals Widespread Ecological Speciation in Flightless Insects.

Recent genomic analyses have highlighted parallel divergence in response to ecological gradients, but the extent to which altitude can underpin such repeated speciation remains unclear. Wing reduction and flight loss have apparently evolved repeatedly in montane insect assemblages and have been suggested as important drivers of hexapod diversification. We test this hypothesis using genomic analyses of a widespread wing-polymorphic stonefly species complex in New Zealand. We identified over 50,000 polymorphic genetic markers generated across almost 200 Zelandoperla fenestrata stonefly specimens using a newly generated plecopteran reference genome, to reveal widespread parallel speciation between sympatric full-winged and wing-reduced ecotypes. Rather than the existence of a single, widespread, flightless taxon (Zelandoperla pennulata), evolutionary genomic data reveal that wing-reduced upland lineages have speciated repeatedly and independently from full-winged Z. fenestrata. This repeated evolution of reproductive isolation between local ecotype pairs that lack mitochondrial DNA differentiation suggests that ecological speciation has evolved recently. A cluster of outlier single-nucleotide polymorphisms detected in independently wing-reduced lineages, tightly linked in an approximately 85 kb genomic region that includes the developmental "supergene" doublesex, suggests that this "island of divergence" may play a key role in rapid ecological speciation. [Ecological speciation; genome assembly; genomic island of differentiation; genotyping-by-sequencing; incipient species; plecoptera; wing reduction.].

Phylomitogenomics provides new perspectives on the Euphasmatodea radiation (Insecta: Phasmatodea).

Phasmatodea species diversity lies almost entirely within its suborder Euphasmatodea, which exhibits a pantropical distribution and is considered to derive from a recent and rapid evolutionary radiation. To shed light on Euphasmatodea origins and diversification, we assembled the mitogenomes of 17 species from transcriptomic sequencing data and analysed them along with 22 already available Phasmatodea mitogenomes and 33 mitogenomes representing most of the Polyneoptera lineages. Maximum Likelihood and Bayesian Inference approaches retrieved consistent topologies, both showing the widespread conflict between phylogenetic approaches and traditional systematics. We performed a divergence time analysis leveraging ten fossil specimens representative of most polyneopteran lineages: the time tree obtained supports an older radiation of the clade with respect to previous hypotheses. Euphasmatodea diversification is inferred to have started ~ 187 million years ago, suggesting that the Triassic-Jurassic mass extinction and the breakup of Pangea could have contributed to the process. We also investigated Euphasmatodea mitogenomes patterns of dN, dS and dN/dS ratio throughout our time-tree, trying to characterize the selective regime which may have shaped the clade evolution.

Multifaceted interactions between the pseudomonads and insects: mechanisms and prospects.

Insects and bacteria are the most widespread groups of organisms found in nearly all habitats on earth, establishing diverse interactions that encompass the entire range of possible symbiotic associations from strict parasitism to obligate mutualism. The complexity of their interactions is instrumental in shaping the roles of insects in the environment, meanwhile ensuring the survival and persistence of the associated bacteria. This review aims to provide detailed insight on the multifaceted symbiosis between one of the most versatile bacterial genera, Pseudomonas (Gammaproteobacteria: Pseudomonadaceae) and a diverse group of insect species. The Pseudomonas engages with varied interactions with insects, being either a pathogen or beneficial endosymbiont, as well as using insects as vectors. In addition, this review also provides updates on existing and potential applications of Pseudomonas and their numerous insecticidal metabolites as biocontrol agents against pest insects for the improvement of integrated pest management strategies. Here, we have summarized several known modes of action and the virulence factors of entomopathogenic Pseudomonas strains essential for their pathogenicity against insects. Meanwhile, the beneficial interactions between pseudomonads and insects are currently limited to a few known insect taxa, despite numerous studies reporting identification of pseudomonads in the guts and haemocoel of various insect species. The vector-symbiont association between pseudomonads and insects can be diverse from strict phoresy to a role switch from commensalism to parasitism following a dose-dependent response. Overall, the pseudomonads appeared to have evolved independently to be either exclusively pathogenic or beneficial towards insects.

Analysis of endemism of world arthropod distribution data supports biogeographic regions and many established subdivisions.

We analyzed 769 242 occurrence records for 115 424 species of terrestrial arthropods, from three biodiversity repositories (Global Biodiversity Information Facility (GBIF), Natural History Museum, London, and "Sistema de Informação Distribuído para Coleções Biológicas" (SpeciesLink)), to test the use of global-scale data points for quantitative assessments of areas of endemism. The data include Insecta (105,941 species), Arachnida (7984 species), Myriapoda (1229) and terrestrial crustaceans (270 Branchiopoda). The species were assigned to 14 543 higher taxonomic groups because such groups often characterize larger areas of endemism. Putative areas of endemism were visualized as sets of cells displaying unique groups of species without the assumption of hierarchical relationships. Yet, the use of 10° grid cells recovered many large areas broadly corresponding to biogeographic Regions (Nearctic, Neotropical, Panamanian, Palaearctic, Afrotropical, Australian, Oceanian and Oriental) albeit with the limits poorly defined. An analysis of 5° grids resulted in 306 sets included in the different biogeographic Realms: Afrotropical, Australian, Madagascan, Nearctic, Neotropical, Oceanian, Oriental, Palaearctic, Saharo-Arabian and Sino-Japanese. The Panamanian Realm comprises 89 partly overlapping sets, crossing the Nearctic and Neotropical boundaries. A total of 7338 species of Insecta were endemic to some areas (Sino-Japanese, Afrotropical, Panamanian, Palaearctic, among others), followed by Arachnida (412 spp) and 105 species in other clades ranked as "classes". Six sets were supported only by genera, except for Panamanian sets that were supported by genera and families. Many of the species in the dataset are included in IUCN red lists, but probably most of those have distributions more restricted than global areas of endemism; only 102 appear as endemic to some area (Neartic, Madagascan, Panamanian, Afrotropical, among others). The results show that data from global databases can be used to identify areas of endemism on a worldwide basis but-owing to their incompleteness-only at a relatively coarse level. At the level of resolution currently allowed by such databases, such global studies are only complementary to studies where areas are determined subjectively by systematists (instead of actual point records), or studies using point records in datasets for specific taxonomic groups curated and compiled by specialists.

Dissecting protein domain variability in the core RNA interference machinery of five insect orders.

RNA interference (RNAi)-mediated gene silencing can be used to control specific insect pest populations. Unfortunately, the variable efficiency in the knockdown levels of target genes has narrowed the applicability of this technology to a few species. Here, we examine the current state of knowledge regarding the miRNA (micro RNA) and siRNA (small interfering RNA) pathways in insects and investigate the structural variability at key protein domains of the RNAi machinery. Our goal was to correlate domain variability with mechanisms affecting the gene silencing efficiency. To this end, the protein domains of 168 insect species, encompassing the orders Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera, were analysed using our pipeline, which takes advantage of meticulous structure-based sequence alignments. We used phylogenetic inference and the evolutionary rate coefficient (K) to outline the variability across domain regions and surfaces. Our results show that four domains, namely dsrm, Helicase, PAZ and Ribonuclease III, are the main contributors of protein variability in the RNAi machinery across different insect orders. We discuss the potential roles of these domains in regulating RNAi-mediated gene silencing and the role of loop regions in fine-tuning RNAi efficiency. Additionally, we identified several order-specific singularities which indicate that lepidopterans have evolved differently from other insect orders, possibly due to constant coevolution with plants and viruses. In conclusion, our results highlight several variability hotspots that deserve further investigation in order to improve the application of RNAi technology in the control of insect pests.

Effects of vegetation management on the composition and diversity of the insect community at Tianjin Binhai International Airport, China.

The vegetation community affects the composition and diversity of the insect community in grasslands. To explore the effects of vegetation management on insect community abundance and diversity, regular mowing of the vegetation was conducted, and tall fescue (Festuca arundinacea) and ryegrass (Lolium perenne) were exclusively planted at Tianjin Binhai International Airport. A total of 1886 insects were collected, representing 8 orders, 23 families, and 29 species; Acrididae (Orthoptera), Coccinellidae (Coleoptera), and Chironomidae (Diptera) were the dominant taxa. The abundance and biomass of insects in the turf areas were significantly lower than those in the control area and were reduced by 45.8 and 48.5% in the ryegrass area, respectively. In all areas, insect abundance and biomass peaked in summer, and the abundance of individuals and taxa decreased as the temperature decreased. Greater diversity and richness were found in summer compared with the other two seasons, and the turf areas had lower diversity and richness indices than the control areas in spring and summer. Our results suggest that the abundance, biomass and diversity of insects can be effectively decreased by artificial regulation of grassland vegetation at the airport, the planting of a single turfgrass - specifically ryegrass had the greatest effect. The present study provides a theoretical basis for the ecological control of insects at the airport.