【Aim】 Invasive species can affect the biodiversity of an invasive site by influencing native species populations through competition. Anoplolepis gracilipes is one of the most destructive invasive ants in the world. This study aims to identify the competitive relationship between A. gracilipes and a dominant indigenous ant species Oecophylla smaragdina in Xishuangbanna, southwestern China. 【Methods】 By combining field investigation and the controlled experiment, the body size, the patterns of foraging activity outside the nest in cold fog season and rainy season, the foraging ability (foraging time and the maximum number of recruited workers within foraging time), the fighting behavior (attack intensity and mortality in different fighting combinations), and the starvation and thirst tolerance (the mean survival time and survival rate along time when no food and water were supplied) between A. gracilipes and O. smaragdina were observed and comparatively analyzed. 【Results】 The body length of A. gracilipes workers (3.66±0.06 mm) was significantly smaller than that of O. smaragdina workers (8.27±0.16 mm). The foraging time of A. gracilipes was longer than that of O. smaragdina in the fog cold season, while the numbers of foraging individuals of both species decreased in the high temperature period of the afternoon in the rainy season. When three different foods (apple, bee honey and sausage) were used as the bait, A. gracilipes only needed 4-8 min to find food, while O. smaragdina needed 8-21 min to find food. After finding food, A. gracilipes workers had the ability to gather their companions faster than O. smaragdina. In the controlled experiments, no attack or low intensity attack occurred predominantly in the combination of one individual of A. gracilipes with one individual of O. smaragdina, and when the number of individuals of either of the two species increased to five, the fighting intensity increased significantly, and both species exhibited intraspecific cooperation. There was no significant difference in the average survival time of workers between the two species under starvation and thirst, but A. gracilipes could survive for 120 h, while O. smaragdina could only survive for 96 h. 【Conclusion】 A. gracilipes exhibits stronger ability to forage and longer activity duration in the fog cold season than the indigenous ant species O. smaragdina in Xishuangbanna, suggesting that A. gracilipes may have strong temperature adaptability. It is necessary to intensify the research on this invasive species, and its population development in this area should be paid close attention to.

 Herbivorous insects and host plants have developed complicated defense and counter defense mechanisms through co-evolution. In this article, we systematically reviewed the roles of insect saliva effectors and elicitors in the interactions between insects and plants and their mechanisms. The salivary elicitors secreted by insects during feeding can be recognized by plants to trigger early plant immunity, while insect effectors released from oral secretion can inhibit plant immune defenses. Resistant plants further evolved R proteins to recognize insect avirulence effectors and initiate effector-triggered immunity. Phytophagous insects can avoid the recognition by plant R proteins through different strategies. Therefore, in this arms race, insect saliva determines whether insects can succeed to feed on plants. During feeding process, chewing insects secrete a large number of enzymes into plants, and piercing-sucking insects secrete sheath saliva and water saliva into plants, but both of them utilize effectors and elicitors to manipulate plant immune responses. By analyzing the reported insect effectors, it was found that the molecular mechanisms of insect effectors are different. They affect plant early defense signals, regulate plant hormone pathways or others, or target small RNA pathways. Recent advances in insect elicitors were also reviewed in this article, revealing that elicitors can induce the release of plant secondary metabolites, and regulate hormone levels, Ca ²⁺ influx and reactive oxygen species (ROS) burst to enhance plant resistance. Finally, we analyzed the secretory characteristics, host specificity and multifunctionality of insect effectors, and discussed research prospects on avirulence effectors and their plant R genes as well as pattern recognition receptors of elicitors. 

 The Calyptratae (Diptera: Calyptratae) comprise 20% of the diversity of Diptera, one of the four superradiations of insects. The Calyptratae are distributed widely in the world, exhibit enormously diverse living habits, play vital roles in maintaining the stability of ecosystem, and are not only the hotspot groups in the studies of vectors, forensic medicine, pollinators and natural enemies of insects, but also key groups for exploring the phylogeny of Diptera and its successful adaptive radiation. To trace the evolutionary history of the Calyptratae, numerous dipterologists have conducted studies at various taxonomiclevels. TheCalyptratae arewellsupportedasa monophyletic group, and divided into three
superfamilies, i.e., Hippoboscoidea, Oestroidea, and Muscoidea, with monophyletic Oestroidea nested within paraphyletic Muscoidea, which are a sister group of Hippoboscoidea. At the family level, the Streblidae (Hippoboscoidea), Anthomyiidae (Muscoidea), Calliphoridae (Oestroidea), and Rhinophoridae (Oestroidea) are paraphyletic, and new families have been established, e.g., Polleniidae (Oestroidea) and Ulurumyiidae (Oestroidea). Therefore, the family level relationship of Calyptratae is still insufficiently resolved. Studies have been performed to reconstruct the evolutionary history of Hippoboscidae (Hippoboscoidea), Streblidae, Nycteribiidae (Hippoboscoidea), Muscidae (Muscoidea), Scathophagidae (Muscoidea), Sarcophagidae (Oestroidea), Gasterophilinae (Oestroidea: Oestridae), in terms of the origin and dispersal, host shift, and feeding habit. However, due to the lack of the biology information of some key groups and a well-resolved phylogeny, the evolutionary history of Calyptratae remains open. In this article we reviewed the research progress of classification, phylogeny and evolution of calyptrate flies, being the first review of the progress of the related research subjects of this group in the phylogenomic era.

【Aim】 To assess the ecological risk of common pesticides to Bombus terrestris, so as to provide a scientific basis for the rational application of pesticides in greenhouses. 【Methods】 The acute oral toxicity and acute contact toxicity of eleven pesticides, including six insecticides (chlorfenapyr, beta-cyhalothrin, flupyradifurone, spirotetramat, isoprocarb, and diflubenzuron), three acaricides (cyflumetofen, fenpyroximate, and bifenazate), and two fungicides (kasugamycin and boscalid), to adult workers of B. terrestris were determined by feeding method and contact method, respectively, and their ecological risk was assessed. 【Results】 Among the 11 pesticides tested, beta-cyhalothrin, isoprocarb and chlorfenapyr showed high acute oral toxicity, flupyradifurone and fenpyroximate showed medium acute oral toxicity, and the others showed low acute oral toxicity to B. terrestris workers. In the acute contact toxicity test, beta-cyhalothrin and isoprocarb showed high toxicity, chlorfenapyr showed medium toxicity, and the others showed low toxicity to B. terrestris workers. The ecological risk assessment showed that isoprocarb and beta-cyhalothrin had medium risk, and flupyradifurone, boscalid, diflubenzuron, fenpyroximate, bifenazate, spirotetramat, kasugamycin and cyflumetofen had low risk to B. terrestris workers via oral and contact exposure, while chlorfenapyr had medium risk via oral exposure and low risk via contact exposure to B.terrestris workers. 【Conclusion】 It is suggested that isoprocarb, beta-cyhalothrin and chlorfenapyr with medium risk should be banned when using B. terrestris pollination in the flowering period of greenhouse crops, flupyradifurone and fenpyroximate should be used cautiously to avoid harm to B. terrestris, while the other six low toxic pesticides could be applied reasonably according to the field conditions, and the ecological risk of pesticides to bumblebees can be reduced by means of ventilation, air drying and interval setting.

【Aim】 In order to provide new actinomycete resources for the development of  antimicrobial drugs, actinomycetes with antimicrobial activity from the gut of Blaps  rynchopetera were explored. 【Methods】 Actinomycetes were isolated from the gut of B.  rynchopetera adults by using dilution coating method and selective culture method. With six  pathogenic bacteria methieillin-resistant Staphylococus aureus, S. aureus, Escherichia  coli, Enterococcus faecalis, Salmonella typhimurium and Pseudomonas aeruginosa, and three  pathomycetes Aspergillus niger, Penicillium expansum and Canidia albicans as the indicator  strains,the antimicrobial activities of secondary metabolites of actinomycetes were tested  by Oxford cup method. Subsequently, 16S rRNA sequence analysis was performed to identify  the 18 strains of actinomycetes with significant activity through molecular biological  method and construct a phylogenetic tree. 【Results】 A total of 176 strains of symbiotic  actinomycetes were isolated from the gut of B. rynchopetera adults. Preliminary  antimicrobial screening showed that among them 46 actinomycete strains had different  degrees of antimicrobial activities. Some actinomycetes exhibited broad-spectrum  antimicrobial activity, with their inhibition zone diameters larger than those of the  positive control drugs. Eighteen actinomycete strains with the inhibition zone diameter  larger than 15 mm were selected for molecular identification, and the results showed that  they were Streptomyces spp. 【Conclusion】 There are abundant actinomycete resources with  antimicrobial activity in the gut of B. rynchopetera. 

There are only one or two voltage-gated sodium channel α subunit genes in insects, but the two post-transcriptional modifications, alternative splicing and RNA editing, confer the functional diversity of insect sodium channels. The insect β accessory subunits, TipE and TEH1-4, also play important roles in the expression and regulation of sodium ion channels. Voltagegated sodium channel plays an important role in the generation and transmission of action potential and is the target site of many natural and synthetic neurotoxins and insecticides, including the pyrethroids, indoxacarb and metaflumizone. Pyrethroids can prolong the transmembrane sodium ion flow by controlling the inactivation and deactivation of sodium channels in insects, causing neuroexcitatory conduction disorders. Indoxacarb and metaflumizone block the neuronal action potential in the central and peripheral nervous system of insects. These neural agents can disturb the normal function of sodium channels in insects. Two pyrethroid binding sites have been commonly identified in sodium channels of insects, but sodium channels of different species have differences in binding sites for pyrethroids. Therefore, in this article we reviewed insect sodium channels and their interaction with insecticides, hoping to promote the research of insect nerve receptors and to provide important references for identification of mutations associated with resistance and development of effective insecticides.

 Litchi stink bug, Tessaratoma papillosa (Hemiptera: Pentatomidae), is one of the most widespread and destructive pest species on litchi (Litchi chinensis) and longan (Euphoria longan) in South China and Southeast Asia. T. papillosa feeds on the buds, tender branchlets, flowers, and fruits of host plants. Furthermore, the nymph over the 3rd instar and adult of T. papillosa are the vectors of witches’ broom pathogen on longan tree. In this article, we provide a detailed review on T. papillosa based on the research over the past 60 years in China, in order to provide references for the further study and development of green control technology of this pest species. T. papillosa is a hemimetabola insect which occurs one generation a year. Its nymphal duration and adult longevity are about 80 d and 203-371 d, respectively. Moreover, averagely one female adult of T. papillosa can deposit 190 eggs in its lifetime. Regarding the life habits, T. papillosa has the aggregation behavior, possesses phototaxis and chromatics tropism, and prefers tender branchlets. By the classification and distribution observation of antennal sensilla, RNA-seq analysis of antennae, dissection and observation of scent gland and comparative analysis of secretary components from scent gland, the two organs of antennae and scent gland of T. papillosa have been more deeply studied and understood. To date, the occurrence of T. papillosa is mainly forecasted through its ovarian development of female adults. Together with the pest forecasting technology, management of T. papillosa mainly depends on chemical control, supplemented by cultural, physical and biological control measures so far. The biological control technology has been reported the most, with aspects of the protection and utilization of natural enemies and the utilization of botanic pesticide. Owing to the seasonal restriction of experimental insect source and geographical limitation of infestation, the research progress of T. papillosa is relatively slow, the in-depth studies are limited and the research fields are relatively narrow. In future study, we can explore the selection mechanism of host plants, the interaction among host plants, natural enemies and symbiotic bacteria, and pesticide resistance from the perspectives of omics, molecular biology, cell biology and other aspects, to provide new clues for green pest control technology of T. papillosa.

 In the long evolutionary process, a variety of forms of interaction between microorganisms and insects have been formed. The wide distribution of microorganisms provides background conditions for their contact with insects and influence on insect behavior. To further explore the phenomenon and mechanism of microorganisms influencing insect behaviors, the research progress of the influence of microorganisms on insect behaviors was reviewed in this article. Host location and selection of insects can be influenced by chemical signal substances produced by microorganisms, and the synthesis of semiochemicals in insects and host plants can also be influenced by microorganisms. Microorganisms have also been found to play important roles in intraspecific and interspecific relationships of insects. Microorganisms can even influence the reproductive behavior of insects by altering, for example, insect sex pheromones. Besides, social and aggregation behaviors of insects are also found to be influenced by semiochemicals synthesized by microorganisms. Considering the current research status of the influence of microorganisms on insect behaviors, the following aspects are suggested to be further investigated: (1) How are semiochemicals that influence insect behavior synthesized in the processes of influencing insect behavior by microorganisms? (2) Do microorganisms involve more interspecies interaction in influencing insect behavior? (3) How do host insects acquire and maintain symbiotic microoganisms that influence insect behavior at certain stages?

The age-stage, twosex life table,called two-sex life-table for short, is an important theory and an analytical tool that are commonly used in population ecology and pest management. The user-friendly TWOSEX-MSChart program, which had been designed based on the twosex life table theory to help researchers for data analysis in insect population studies, has been more and more widely used by increasing numbers of scientists around the world. There are many statistical techniques and computer simulations embedded in the TWOSEX program, and the bootstrap technique is one of the major procedures included in the program. In this article, we describe the principles, methods, advantages/disadvantages, and the application of the bootstrap technique in the twosex life table analysis, as well as the application of the multinomial theorem in life table research. Compared with the general statistics, the bootstrap technique can be used to estimate and infer the distribution characteristics of data without the assumption of data distribution. In the twosex life table analysis, the bootstrap technique can not only be used to estimate the population parameters or the variances and standard errors of general statistics, but also to be used to assess the differences between treatments by paired bootstrap test to accurately show the population variability. The same bootstrap samples can be used to calculate the hatching rate and the contribution of different reproductive forms to population parameters, and to link the life table and predation rate analysis of natural enemies for an accurate analysis of the reproduction and predation potential of natural enemies. In addition, we also introduce the multinomial theorem, i.e., the mathematical basis of the bootstrap technique. The application of the multinomial theorem demonstrates that stable and reliable estimates can be obtained by using the bootstrap technique. We also elaborate the necessity of considering the ineffective bootstrap samples in the life table research. In recent years, although the twosex life table and the bootstrap technique had been widely adopted in research, few reports discussed the principles and methodology involved. This article will help interested researchers in entomology and ecology understand the basic theories and principles of the bootstrap technique and the multinomial theorem, and their application in twosex life table analysis, so as to better apply them in the related scientific research projects.

【Aim】 The rice stem borer, Chilo suppressalis, is a destructive rice pest in China and other Asian countries. However, due to lack of genetic tools, the functional genomic studies in C. suppressalis are seriously constrained. The aim of the study is to use a marker gene, ebony, to establish a gene editing system based on CRISPR/Cas9 technology in C. suppressalis. 【Methods】 With the amino acid sequences of Bombyx mori ebony protein as a query, the putative C. suppressalis ebony gene was obtained on its genomic database by the TBLASTN program. The full-length cDNA of ebony gene of C. suppressalis was cloned by PCR and subjected to bioinformatical analysis. The expression patterns of Csebony at different developmental stages (egg, larval, pre-pupal, pupal, and male and female adult stages) and in multiple tissues (head, epidermis, fat body, gut, and Malpighian tubules) of the 4th instar larvae of C. suppressalis were analyzed by qRT-PCR. Finally, we performed targeted knockout of ebony gene in C. suppressalis by microinjecting the ribonucleoprotein complexes specific guide RNA/Cas9 protein into the newly laid eggs within 2 h based on the CRISPR/Cas9 gene editing technology. 【Results】 The full-length cDNA of Csebony gene (GenBank accession no.: MZ846208) of C. suppressalis was cloned. It contains a 2 586 bp ORF encoding 861 amino acids, with the molecular mass of 9.5 kD and theoretical isoelectric point of 5.10. Csebony has no signal peptide sequence at the N-terminus. Domain analysis showed that Csebony has three conserved domains. Phylogenetic analysis indicated that Csebony is most closely related to Ostrinia furnacalis ebony. The qRT-PCR results showed that Csebony was highly expressed in the pupal stage and head. Knockout of Csebony caused melanin pigmentation in larvae, pupae, and adults of C. suppressalis. 【Conclusion】 The results showed that Csebony is involved in regulating cuticle pigmentation of C. suppressalis, and CRISPR/Cas9-based genome editing technology is effective in C. suppressalis. We can use visible marker gene to establish CRISPR/Cas9-based genome editing system in non-model organisms, so as to offer a valuable genetic tool for the study of functional genomics in C. suppressalis.

【Aim】 The grain aphid, Sitobion miscanthi, is a dominant cereal aphid species in the major growing areas of wheat ( Triticum aestivum) of China. Sm13498 is a salivary protein specifically expressed in the salivary glands of S. miscanthi. This study aims to investigate the potential role of the functionally unknown salivary protein Sm13498 of S. miscanthi in modulating plant defense. 【Methods】 Based on the sequencing data of the salivary gland transcriptome of S. miscanthi, the full-length cDNA sequence of Sm13498 gene was cloned by PCR and analyzed by bioinformatics. The expression levels of Sm13498 in apterous adults of S. miscanthi feeding on T. aestivum leaves for different time were determined by RT-qPCR. The secretion function of the signal peptide of Sm13498 was verified by yeast secretory system. The function of Sm13498 and its subcellular localization in Nicotiana benthamiana was examined using Agrobacterium tumefaciens-mediated transient expression technique. 【Results】 The full-length cDNA sequence of Sm13498 of S. miscanthi was cloned (GenBank accession no.: MW346655). Its open reading frame (ORF) is 783 bp in length, encoding 260 amino acids with the predicted molecular weight of 28.01 kD and amino acids 1-22 predicted to be N-terminal signal peptide. Phylogenetic analysis showed that Sm13498 was most closely related to LOC100159087 precursor, an uncharacterized protein of Acyrthosiphon pisum, deposited in GenBank under the accession no. NP_0013135481, sharing 71.7% amino acid sequence identity. The RT-qPCR results revealed that the expression level of Sm13498 reached the peak in apterous adults of S. miscanthi feeding on wheat leaves for 12 h. Saccharomyces cerevisiae strain YTK12 containing the signal peptide fragment of Sm13498 grew normally on the YPRAA medium in the yeast secretion system, and catalyzed the conversion of colorless 2,3,5-triphenyltetrazolium chloride (TTC) to insoluble dark-red-colored triphenylformazan (TTF), confirming the secretion activity of the predicted signal peptide. The transiently expressed Sm13498 in N. benthamiana mediated by A. tumefaciens could suppress the programmed cell death induced by Bcl-2-associated X protein (BAX) and pathogen elicitor INF1. Subcellular localization results indicated that the fusion protein  Sm13498-GFP was localized in the cytomembrane of N. benthamiana leaves. 【Conclusion】 The results suggest that the salivary protein Sm13498 of S. miscanthi may be involved in the suppression of plant defense responses. This study lays a foundation for identifying the salivary effectors of S. miscanthi and understanding the high adaptability of wheat aphids to wheat varieties.

 There are a large number of symbionts in the brown planthopper (BPH), Nilaparvata lugens, and these symbionts exhibit the diversity not only in their species but also in their functions on hosts. Up to now, 19 and 53 genera of symbiotic fungi and bacteria (sequencing abundance＞0.1%), respectively, have been identified by using molecular biological methods and high-throughput sequencing technology, but plenty of symbionts remain unknown in taxonomic status due to technical limitations and their unculturable characteristics. Symbionts play vital roles in the life activities of BPH including the growth, development, reproduction, nutritional metabolism, resistance variation and immune function, and various symbionts have different functions. The symbiotic fungi are mainly involved in the synthesis of sterols and essential amino acids, while the symbiotic bacteria mainly take part in the synthesis of vitamins. The symbionts have important influence on the virulence variation, the development of high resistance to insecticides and the reproduction of host BPH, but the molecular mechanisms have not yet been clarified. In this article we reviewed the diversity of symbionts of BPH and prospected the focal points of future research including the species identification of symbionts of BPH, the functional studies of specific and single species of symbionts, the diffusion pathway, diffusion species and regulatory mechanism of symbionts in different tissues of BPH, and the control of BPH using symbionts as targets.

【Aim】 The study aims to determine the morphological characteristics and life history of three lepidopteran pest species damaging Elaeagnus mollis in Shanxi Province, North China, and to provide rapid and accurate identification of the three species based on DNA barcodes of mtDNA COI gene. 【Methods】 The external morphology of three lepidopteran pest species on E. mollis in Shanxi was observed, and the internal structures of female and male genitalia were illustrated. The DNA barcode sequences of COI gene were obtained through PCR amplification and compared against reference sequences in GenBank database and used to generate neighbor-joining (NJ) tree. Based on the DNA barcode sequences of COI gene in combination with morphological identification results, the three lepidopteran pests were identified. 【Results】 The results of morphological identification showed that the three lepidopteran pests damaging E. mollis are Synanthedon ulmicola, Synanthedon sp., and Apotomis sp.. The external morphology and female and male genitalia were described and illustrated. DNA barcode analysis showed that the COI gene sequences of S. ulmicola and Synanthedon sequoia in GenBank database show 90.7% nucleotide sequence identity, those of Synanthedon sp. and Synanthedon spheciformis in GenBank database show 90.0% nucleotide sequence identity, and those of Apotomis sp. and Apotomis capreana in GenBank database show 92.7% nucleotide sequence identity. NJ tree analysis showed that the three species formed distinct monophyletic branches, consistent with the results of morphological identification. 【Conclusion】 In this study, three species of lepidopteran pests of E. mollis, S. ulmicola, Synanthedon sp. and Apotomis sp., were determined by using a combined morphological and DNA barcoding approach for species identification. Morphological characteristics and life history of the three species were provided. Our findings will be helpful for pest management of the important economic tree species E. mollis.

 The halteres in dipteran insects evolved from the hindwings and play an important  role in flight. The sensilla at the base of halteres detect the inertial force and provide  feedback to motor neurons that subsequently balance body during flight. The haltere of  insects is developed from imaginal disc and regulated by the HOX gene (Ultrabithorax, Ubx).  Mature haltere is composed of two layers of epithelial cells. The bulb is filled with  vacuolar cells, while the base possesses various sensilla. Interestingly, the halteres  controlled by independent muscles move antiphase relative to ipsilateral wing. However, the  winghaltere coordination is essential for departure and maintaining balance. Recently,  the navigation principles of halteres have been increasingly applied in bionics, and  navigation devices of aircrafts have been developed based on the structure and functions of  halters of flies. In this article we reviewed the progress in the research on the  development, morphological structure, function and bionics application of halteres with the  goal of providing a theoretical basis for further understanding the developmental  meachanisms and biological functions of halteres in insects.

【Aim】 The solitary wasp, Anterhynchium flavomarginatum is one of the most  important natural enemies for the control of agricultural and forestry pests. This study  aims to investigate the oviposition strategy and behavioral responses of A. flavomarginatum  to parasitism pressure, so as to provide a basis for the biological control of agricultural  and forestry pests. 【Methods】 During the three years (2018-2020), the oviposition  strategy of A. flavomarginatum and its relationships with parasite pressures were  investigated by using artificial trap-nests set according to kilometer-grid protocol  (N=100 1-km² grids) in the Chebaling National Nature Reserve and its surrounding areas,  Guangdong Province. The number of brood cells, sex ratio and parasitism in each trap-nest  were recorded, and the length, innerdiameter, and architecture of each trap-nest were  measured as well. 【Results】 During 2018-2020, we obtained 3 733 trap-nests and 9 269  brood cells with up to 1 420 brood cells parasitized. A. flavomarginatum laid an average of  2.50±1.25 eggs and constructed 1.84±1.14 non-brood cells per trap-nest with a  male-biased sex ratio (male∶female=1.98∶1). For each nest-trap, offspring females tend  to be laid in inner brood cells, while offspring males tend to be laid in outer brood  cells. Structural equation model showed that both the inner diameter and the length of trap -nest positively affected the number of brood cells per trap-nest. The length of  trap-nest also significantly positively affected the number of non-brood cells per trap- nest. However, both the number of brood cells and non-brood cells had a significantly  negative influence on the parasitism rate. Meta-analysis of the sex arrangement pattern of  offspring showed that number of offspring females in the innermost part of trap-nest was  significantly higher than that in the outermost part, while the parasitism rate in the  innermost part of trap-nest was significantly lower than that in the outermost part.  【Conclusion】 Our results provide sound evidence that oviposition strategy by A.  flavomarginatum can help to improve its reproductive fitness, since this species tends to  lay more eggs in trap-nests to reduce the parasitism risk and to improve the survival of  offspring females by adjusting the sex allocation pattern of offspring within each  trap-nest.

As a traditional interdiscipline, the content of chemical ecology is becoming more and more abundant in solving the problems of agricultural and forestry production and human health. Meanwhile, the application of new techniques has greatly promoted the development of the chemical ecology by deepening and widening our understanding of chemical communication among organisms. Articles in this special issue of “Insect Chemical Ecology” reflect, to a certain extent, the characteristics of chemical ecology research in China, i.e., agricultural and forestry orientation, application of both traditional and modern techniques, and almost keeping pace with international levels. In the era of omics, chemical ecology, with its interdisciplinary characteristics and by strengthening collaboration among scientists of different fields, will certainly play more important roles in different areas including food safety, ecological conservation, as well as for solutions of global climatic change.

【Aim】 Gammaaminobutyric acid (GABA) is an important neurotransmitter in animal nervous system. This study aims to identify the GABA receptor (GABAR) familygenesinthewestern flower thrips, Frankliniella occidentalis, and to clarify the role of ionotropic receptor (GABA_AR) in the resistance evolution to spinosad in F. occidentalis. 【Methods】 Based on the genomeand transcriptome data of F. occidentalis, the GABAR genes were identified, cloned and analyzed with bioinformatics tools. The expression patterns of the GABA_AR subunit genes, FoRDL, FoLCCH3, and FoGRD in the spinosad susceptible strain of F. occidentalis at different developmental stages (1st-2nd instar nymphal, pupal, and adult stages), and their expression differences between the spinosad susceptible and resistant strains of F. occidentalis at the adult stage were detected by qPCR. After treatment with 0.250 and 0.400 mg/L spinosad at 24 h post RNAi of FoRDL in the 3-day-old adults of the spinosad susceptible strain of F. occidentalis, the mortality rates of F. occidentalis adults were determined by bioassay. 【Results】 Eight GABAR genes including FoRDL, FoLCCH3, FoGRD, FoGRD-like1, FoGRD-like2, FoB1, FoB2, and FoB-like (GenBank accession numbers: MH148151-MH148158) were annotated and cloned, and their ORF lengths vary from 1 080 to 3 720 bp. Phylogenetic analysis showed that GABAR genes of F. occidentalis were clustered with the corresponding genes of other insect species, indicating high conservativeness. GABA_AR subunits FoRDL, FoLCCH3 and FoGRD all have a typical nitrogen-terminal extracellular region loop structure (loop A-F) and four transmembrane regions (TM 1-4), and exon 3 of FoRDL has mutually exclusive splicing. The expression levels of FoRDL, FoLCCH3 and FoGRD in the spinosad susceptible strain of F. occidentalis increased with the developmental stage of F. occidentalis, and the expression peak occurred at the adult stage. The expression level of FoRDL in the spinosad resistant strain of F. occidentalis at the adult stage was significantly lower than that in the susceptible strain at the adult stage. After treatment with 0.250 and 0.400 mg/L spinosad following RNAi of FoRDL in the susceptible strain of F. occidentalis, the mortality rates of F. occidentalis adults decreased significantly by 55.80% and 43.00%, respectively, as compared to those of the control. 【Conclusion】 Five ionic and three metabotropic GABAR genes have been identified in F. occidentalis. FoRDL may play a role in the resistance evolution to spinosad in F. occidentalis.

 【Aim】 Bursicon secreted by nervous system is a heterodimer neuropeptide and plays an important role in regulating cuticle hardening and wing expansion of insects during molting cycle. This study aims to investigate the relationship between Bursicon genes and the genes involved in wing development and fecundity in Bombyx mori and to ascertain their role in regulating wing expansion and fecundity. 【Methods】 The RNAi technique was used to silence the Bursicon genes by injecting Bursicon dsRNA (ds BmBurs-α, ds BmBurs-β and ds BmBurs-α+ds BmBurs-β) into the 1-day-old pupae of B. mori, and the individuals injected with ds GFP were used as the control. After RNAi, the phenotype of B. mori was observed, and the number of eggs laid per female was calculated. The real-time quantitative PCR technology was used to detect the expression levels of wing development-related genes ( BmWg, BmFt, BmFj and BmDs)  in the 24 h-old adults of B. mori and reproduction-related genes (vitellogenin gene BmVg and vitellogenin receptor gene BmVgR) in pupae at 48 and 72 h after RNAi. 【Results】 After RNAi of Bursicon genes, the wings of the 24 hold adults of B. mori were not able to expand normally. In the three treatment groups injected with ds BmBurs-α, ds BmBurs-β and ds BmBurs-α+ds BmBurs-β, the wing deformity rates were 93.33%, 96.67% and 96.43%, respectively, and the average numbers of eggs laid per female were 312.67, 332.00 and 284.00, respectively, significantly lower than that of the control (406.00). After RNAi of Bursicon genes, the expression levels of Bursicon genes BmBurs-α and BmBurs-β in B. mori decreased significantly, and the expression levels of the related genes BmWg, BmFt, BmFj, BmDs, BmVg and BmVgR were significantly lower than those of the control group. 【Conclusion】 Bursicon genes are involved in regulating wing expansion by regulating the transcription levels of genes related to wing development in B. mori. They also regulate the expression of reproduction-related genes BmVg and BmVgR, and thus influence reproduction in B. mori.

Insect odorant receptors (ORs) play critical roles in the peripheral olfactory system and are involved in such vital life events in insects as feeding, mating and oviposition. With the development of sequencing technologies and bioinformation tools, insect OR genes have been widely identified in recent years. In this article, we comprehensively reviewed the research methods of insect OR genes, and their principles, advantages and disadvantages. Furthermore, we summerized the numbers and proportions of research methods published for identification and functional studies of ORs since 2015. Besides, we listed the research advances of ORs in serious insect pests. A total of 2 543 and 5 111 OR genes had been respectively identified through genome and transcriptome sequencing analyses during 2015 to 2019. Gene expression and protein localization analysis are used to analyze the expression specificities of OR genes in different tissues and developmental stages. The in situ hybridization and immunohistochemistry are used for analyzing cellular and tissue localization, while the semi-quantitative reverse transcription PCR (RT-PCR) and quantitative real-time PCR (qRT-PCR) are often used to study the spatiotemporal expression profiles of OR genes. Otherwise, cryo-electron microscopy (Cryo-EM) is employed to elucidate the OR micro-crystal structure and to demonstrate the interactions between critical amino acid residues and ligands. Multiple approaches are developed for functional characterization of ORs. In vitro heterologous expression systems are commonly used to study the function of insect ORs, representing 75.76% of the research methods published from 2015 to 2019. The most abundantly used in vitro systems are through heterologous expression in Xenopus oocytes with two-electrode voltage clamp system (43.94%), followed by transgenic Drosophila with single sensillum recording (SSR) technique and cell line expression systems with calcium imaging. In vivo research methods include RNA interference (RNAi) and clustered regularly interspaced short palindromic repeats (CRISPR)-associated nuclease Cas9 (CRISPR/Cas9) gene edting technique. The latter has made great breakthroughs in OR deorphanization, and has a great prospective application for further studies. Finally, we suggest the future research directions for insect ORs including, (1) studying the molecular mechanism of olfaction in serious insect pests and natural enemies; (2) elucidating the molecular mechanism of synergism to insect sex pheromones and host plant volatiles; (3) analyzing the micro-crystal structure of ORs and explore the specific recognition mechanisms of ORs and odorants; and (4) developing behavioral regulation products in insects through RNAi technique.

 Fat body is a multifunctional organ in insects, similar to the liver of vertebrates, and is distributed in the abdomen, thorax and even the head cavity of insects, with the abdominal fat body being the most developed. The fat bodies of honeybees can be divided into two types, peripheral fat body and perivisceral fat body, and are composed of trophocytes, urocytes and oenocytes. As in other insects, the fat body plays an important role in life activities in honeybees, and its morphology and function vary with the developmental stage, season, and division of labor. The structure of fat body is relatively simple, but its physiological function is very complex. The major function of fat body is the storage and metabolism of energy substances. Fat body is not only a central storage pool of nutrients (i.e., lipids, carbohydrates and proteins) for honeybees, but also an intermediate station for nutrient metabolism, with a variety of enzymatic systems for the interconversion of energy and substances, undertaking the supply of metabolic water and synthesizing purines and pyrimidines and many important proteins. At the same time, fat body is the exchange center for various hormonal and nutritional signals during insect development and behavior regulation, and fat body hormones and nutritional signals are involved in regulating fat body development, nutrient metabolism, reproduction and labor division in honeybees. Fat body has a variety of functions including energy storage and release, biosynthesis and catabolism, regulation of nutrient perception, integration of metabolic signals, endocrine regulation, immunity and detoxification, magnetic field perception, improved cold resistance, and protection of organs in the body cavity. Given the important roles of the fat body, a review of the research progresses in the morphology and function of honeybee fat body can provide references and ideas for the analysis of insect nutritional signaling pathways, highquality bee species breeding and control of honeybee diseases.

【Aim】 To screen and detect the regulation of histone methylation modification in 20-hydroxyecdysone (20E) signaling transduction by CRISPR/Cas9 knockout system in Drosophila melanogaster cells. 【Methods】 Histone methyltransferases of D. melanogaster and their modification sites were analyzed and summarized from Flybase website. After transfection of the constructed knockout vector pAc-sgRNA-Cas9 inserted with the sgRNA of five histone methyltransferase genes ［ trr, Mes-4, ash1, Su( var)3-9 and egg］ into Kc cells of D. melanogaster, the gene mutation was detected by TA cloning and sequencing. Taking Trr inducing 20E primary response gene Br-C as a positive control, qRT-PCR and Western blotting were used to test the validity of pAc-sgRNA-Cas9 knockout system. The dual luciferase assay of 20E response element (EcRE) was used to determine whether trr, Mes-4, ash1, Su(var)3-9 and egg participate in 20E signaling transduction. 【Results】 Drosophila histone methylation modification occurs mainly on histone H3 lysine residues and less on H3 arginine residues. Besides, there was less methylation modification on histone H4. After the transfection of its knockout vector pAc- trr-sgRNA-Cas9 in Kc cells, trr was mutated successfully, the tri-methylation level of H3K4 was reduced, and the 20E-induced transcriptional level of its primary response gene Br-C was inhibited, indicating the validity of this knockout system. Besides trr, Mes-4 and egg knockouts also reduced the dual luciferase activity of EcRE. 【Conclusion】 The pAc-sgRNA-Cas9 knockout system inserted with sgRNA of target gene is effective and fast for gene mutation in Drosophila Kc cells. Using this knockout system, in addition to Trr, Mes-4 and egg were found to participate in the regulation of 20E signaling transduction via manipulating the activity of EcRE. This study lays the theoretical basis and work foundation for CRISPR/Cas9-mediated gene knockout in insect cells and further studying histone methylation modification involved in regulating 20E signaling transduction.

 【Aim】As the main vector insect of pine wilt disease by Bursaphelenchus xylophilus in the middle and temperate zone of China, Monochamus saltuarius has caused very serious destruction to pine trees in Liaoning, Northeast China in recent years. In this study the supplementary nutrition of M. saltuarius on Pinus koraiensis was boserved and analyzed so as to provide a theoretical basis to determine the biological characteristics of M. saltuarius, to evaluate its population density and damage degree in the forest, and to determine its transmission law of pine wood nematode. 【Methods】 The newly emerged male and female adults of M. saltuarius were placed in pairs in a transparent glass jar filled with segments and branches of P. koraiensis. Under the condition of temperature 23±3℃, relative humidity 55%±5%, and photoperiod 16L∶8D, the main parts of P. koraiensis fed by M. saltuarius adults, the feeding amount of M. saltuarius adults on different parts of P. koraiensis, the adult longevity, average feeding frequency, average time of each feeding and variation rule of feeding amount with developmental time, and the circadian rhythm of the proportion of feeding frequency of M. saltuarius adults on P. koraiensis branches were continuously observed until their natural death. 【Results】 M. saltuarius adults preferred to feed P. koraiensis needles, followed by branches and buds, with the proportion of the total feeding amount of 7711%, 21.46% and 1.43%, respectively. The average longevity of M. saltuarius adults on P. koraiensis branches was 16.63±6.63 d, being 17.11±5.91 d for females and 16.14±6.77 d for males. The feeding behavior of M. saltuarius adults on P. koraiensis occurred on the 4th day after emergence, and the daily feeding amount increased first and then decreased with the developmental time, and the highest feeding amount was on the 16th day, being 526.48 mm ². The feeding behavior of M. saltuarius adults occurred in every hour throughout the day, and the daily feeding frequency of male and female adults showed a state of increasing and decreasing repeatedly. 【Conclusion】 When M. saltuarius adults are reared indoors with P. koraiensis, their feeding starts on the 4th day after emergence, and there is no obvious regularity in the daily feeding amount and feeding rhythm. The feeding characteristics of adult M. saltuarius in the forest need to be further studied.

 Insects mainly rely on the olfactory system to seek foods, find mates, control mating, select oviposition sites and avoid natural enemies. Olfactory system is crucial for insect reproduction and survival. Odorant receptor (OR) is one of the key components of the olfactory system in insects. ORs can be activated by semiochemicals and then trigger special behaviors. With the development of sequencing technique, genomes and transcriptomes of plenty of agricultural insects have been sequenced, and OR gene families are analyzed and acquired from the sequencing data. Heterologous expression system and CRISPR/Cas9 system are frequently used in the research of OR functions nowadays. Heterologous expression system combined with recording system can be used to express target ORs and screen ligands. CRISPR/Cas9 system can be used to knock out target OR genes from insect chromosome, and then their functions are studied by electrophysiological techniques and behavioral experiments. In this article we systematically summaried the odorantresponse spectra and functions of the ORs of 30 agricultural insect species in six orders, Lepidoptera, Orthoptera, Hemiptera, Diptera, Hymenoptera and Coleoptera, particularly in Lepidoptera. Sex pheromones of agricultural insects are usually produced by females and consist of blends of two or more components at certain ratios, including behavioral antagonists involved in interspecific reproductive isolation. So several sex pheromone receptors in one species will be used to sense these pheromonal messages and then regulate intra- and inter-specific sexual behaviors. Some ORs are mainly tuned to plant volatiles including floral scent compounds, which play roles in host plant selection and oviposition site selection. Aggregation pheromone receptors can be activated by aggregation pheromones triggering aggregation behavior. Alarm pheromone receptors can be activated by alarm pheromones eliciting repellent behavior. Studies of odorant-response spectra and functions of ORs of agricultural insects will lay solid foundations for developing sex attractants, food attractants, antifeedants and aggregation pheromones used in pest control. At last we suggested the main research directions in the future for the agricultural insect ORs, including: (1) developing new heterologous expression systems for ORs; (2) investigating the functions of sex pheromone receptors in females specifically tuned to male-emitted sex pheromone components; and (3) exploring the molecular mechanisms of OR-odorant specific interactions.

Eusociality is a major characteristic of ants (Formicidae), with apparent division of labor among individuals. They use complex cooperative strategies to protect their nests from predators, pathogenic microorganisms, and ant competitors, and to capture preys. Myrmicinae is the largest group of Formicidae, with 147 living genera. They mainly spray alkaloid-rich venom secretions for defense and hunting. In this article, the composition of defensive alkaloids of Myrmicinae ants and their distribution characteristics in different genera and species were reviewed, whose chemical structure mainly includes piperidine, pyridine, pyrrole, indolizidine, pyrrolizidine and fatty amine, and their function and application were summarized and prospected. Piperidine alkaloids are the typical characteristics of the venom of Solenopsis species, while pyrrolidine, pyrroline, and pyrrolizidine alkaloids predominate in the venom of M onomorium species. Indolizidine alkaloids are the major components of the venom secretion of Myrmicaria ants and Solenopsis thief ants. In addition, fatty amines are also components of the venom of Monomorium species. These venom alkaloids possess a variety of biological activities and have great application value in development of pesticides and biomedicines.

【Aim】 This study aims to analyze the effect of imidacloprid treatment on the olfactory learning behavior and the gene transcription in the brain of Apis mellifera ligustica so as to provide evidence for the negative effects of neonicotinoid insecticides on honeybees. 【Methods】 Under laboratory conditions, A. m. ligustica adult workers were fed with 50% sucrose solution containing 4 ng imidacloprid at one time, with those fed with 50% sucrose solution without imidacloprid as the control, and its effect on the olfactory learning behavior of A. m. ligustica adult workers was measured via proboscis extension response (PER) behavior test. Total RNA was extracted from the brain of A. m. ligustica workers tested above for RNA-Seq sequencing and bioinformatics analysis. To verify the RNA-Seq sequencing results, the expression levels of six selected differentially expressed genes (DEGs) in the brain of A. m. ligustica adult workers were detected by real-time fluorescent quantitative PCR. 【Results】 The olfactory learning ability of A. m. ligustica adult workers fed with 50% sucrose solution containing 4 ng imidacloprid was significantly decreased as compared to the control group (fed with 50% sucrose solution). RNA-Seq sequencing results showed that there were 123 DEGs [adjusted P-value (padj)<0.05］ between the treatment group and the control group, including 82 down-regulated DEGs and 41 up-regulated DEGs. GO enrichment analysis revealed that the down-regulated DEGs were mainly enriched in S-adenosylmethionine-dependent methyltransferase activity, acid phosphatase activity, oxidoreductase activity, and protein heterodimerization activity. The up-regulated DEGs were mainly enriched in functional items such as transmembrane receptor activity, molecular transducer activity, and neurological system processes. KEGG enrichment analysis showed that the down-regulated DEGs were mainly enriched in such organelles as ribosome and lysosome, metabolism pathways like carbon metabolism and tryptophan metabolism, and Toll and IMD signaling pathways, while the up-regulated DEGs were not enriched in KEGG pathways. Real-time fluorescent quantitative PCR results showed that the relative expression levels of the six DEGs tested showed the same trend with the RNA-Seq sequencing results of FPKM (fragments per kilobase million) value, verifying the reliability of the sequencing results. 【Conclusion】 Exposure of sublethal dose of imidacloprid significantly reduces the olfactory learning ability of A. m. ligustica adult workers, and also affects the expression of immune and detoxification related genes, enzyme activity, redox and other biological metabolic processes in the brain of A. m. ligustica. Short-term stress of sublethal dose of imidacloprid can stimulate the olfactory sensory process and nerve signal transduction process of A. m. ligustica.

【Aim】 Since pine wilt disease spreads to the middle temperate zone of China, Monochamus saltuarius has become a new vector of pine wood nematode in northern China. Due to the abundant pine tree species damaged by the pine wood nematode in the middle temperate zone, the preferences of M. saltuarius to four host pine trees in the process of supplementary nutrition were assessed in this study, in order to provide theoretical basis for the prevention and control of M. saltuarius and the monitoring of pine wilt disease in the middle temperate zone. 【Methods】 Before the flight period of M. saltuarius on May, 2020, Pinus koraiensis trees infected by M. saltuarius were collected from Dahuofang Experimental Forest Farm in Fushun City, Liaoning Province. The infested trees were sawed into 1 m long logs, sealed with wax at both ends, and kept in insect cages. The newly emerged adults were collected every day. Three-year-old seedlings of host plants P. koraiensis, P. tabulaeformis, P. sylvestris var. mongolica and Larix olgensis were put into the four corners of the cage, respectively. Five male and five female adults emerged on the same day were placed in the center of the cage, and the daily feeding frequency on different host pine trees and average daily feeding amount on different parts of host pine trees were investigated. 【Results】 In the cage, M. saltuarius mainly stayed on P. tabulaeformis, with the daily feeding frequency of 7.05±3.87, followed by on P. koraiensis and L. olgensis. The daily feeding frequency of staying on P. sylvestris var. mongolica was the least (1.02±0.81). The daily feeding frequencies on different species of host pine trees were significantly different between male and female adults. The feeding amounts of M. saltuarius adults on four species of pine trees were significantly different. The daily feeding amount of M. saltuarius adults on P. tabulaeformis was the highest (129.14±50.23 mm²), accounting for 62.89% of the total feeding amount, followed by those on P. koraiensis and L. olgensis. And that on P. sylvestris var. mongolica was the least (9.87±11.02 mm²), accounting for only 4.81% of the total feeding amount. The feeding amounts on different parts of the same pine tree were significantly different, and M. saltuarius adults mainly fed on the tender branches of four species of pine trees.【Conclusion】 Based on the analysis of the feeding frequency and feeding amount of M. saltuarius on different pine tree species during the period of supplementary nutrition, the preference of M. saltuarius to P. tabulaeformis is significantly higher than to the other three pine trees.

 Subspecies is a subunit of species, and its status is questioned because of different definitions and subjectivity in taxonomy. However, all attempts either to replace the subspecies by a different terminology or to abandon it altogether have been found unacceptable in taxonomic practice. Subspecies, as a part of the natural process, are also an important part of biodiversity, and with certain uniqueness, they also have values in conservation. Based on subspecies concepts and characteristics, it is proposed that two principles, geographical isolation (such as allopatric distribution) and differences in phenotype, should be applied in subspecies taxonomy. In this article, we reviewed the application and problems of the two principles with the rare butterflies of Teinopalpus as examples, collected the data of geographic distribution, morphological descriptions of subspecies taxonomy or related literatures of this butterfly genus, and summarized the status, problems and causes in the subspecies taxonomy of this genus. From 1843 to 2007, eight subspecies were recorded in T. imperialis and its sister species T. aureus, respectively. However, some subspecies were applied simultaneously in one administrative region, such as T. i. imperialis, T. i. himalaicus and T. i. behludinii all were applied in Sichuan Province of China, and two subspecies were recorded together in Zhejiang Province of China, indicating uncertainties in subspecies application. Considering that both the two sister butterflies were distributed (sympatric) in Southeast Asia, the geographical isolation between subspecies was then determined by comparing the consistency of locations of their holotype specimens in biomes and ecoregions. The niche differentiation in T. imperialis (over three biomes) could be higher than that in T. aureus (with only one biome). According to the isolation of ecoregion, we suggest that the subspecies taxonomy of T. imperialis should be revised as the seven subspecies T. i. imperialis, T. i. himalaicus, T. i. miecoae, T. i. behludinii, T. i. imperatrix (including T. i. bhumipholi), T. i. gillesi and T. i. gerritesi in T. imperialis, and that of T. aureus as T. a. aureus (including T. a. wuyiensis, T. a. guangxiensis and T. a. nagaoi), T. a. eminens (including T. a. laotiana), T. a. shinkaii and T. a. hainani. Due to the lack of reference specimens, the information available for morphological comparison is limited and incomplete (such as only unisexual comparison in morphology), so it could lead to over-subspecialization. In rare butterflies, subspecies problems such as over-subspecialization and uncertainty would affect management in conservation, since governors usually make decision after weighing costs and effectiveness and identifying priorities in regions or species in conservation. Therefore, subspecies taxonomy should not be recommended until more definitive information available.

【Aim】 Based on the important role of insect gut microorganisms in host health, growth and development, this study aims to preliminarily explore the diversity and differences of gut bacterial communities in different instar larvae and diapause prepupae of Colleles gigas. 【Methods】 The V3-V4 gene fragment of 16S rRNA was amplified by PCR using the bacterial DNA extracted from the gut contents of the 1st-5th instar larvae and diapause prepupae of C. gigas collected from the field, and was sequenced by IlluminaMiseq second-generation high-throughput sequencing technology. Based on the obtained sequence data, the composition, abundance and diversity of gut bacteria of larvae and diapause prepupae of C. gigas were analyzed by bioinformatics methods. 【Results】 Bacteria of 15 phyla, 23 classes, 43 orders, 80 families and 128 genera were detected in the gut bacterial communities of C. gigas larvae, of which the main phylum, order, family and genera were Proteobacteria (accounting for 93.74%), Rickettsiales (accounting for 68.68%), Anaplasmataceae (accounting for 68.64%), and Wolbachia (accounting for 68.64%), respectively. Beta diversity analysis showed that the gut bacterial community changed with the development of larvae, and could be divided into three groups: early instar group (1st-3rd instar larva), late instar group (4th-5th instar larva) and diapause prepupa group. Alpha diversity analysis showed that there was a significant difference in the gut bacterial diversity between the diapause prepupa group and the late instar group and early instar group, while the gut bacterial diversity between the late instar group and the early instar group showed no significant difference. The linear discriminant analysis results showed that there was significantly dominant class in both diapause prepupa group and early instar group, being Alphaproteobacteria and Gammaproteobacteria, respectively, but no dominant class existed in the late instar group. At the order level, Enterobacteriales and Pseudomonadales were dominant in the early instar group, and Rickettsiales was dominant in the diapause prepupa group. At the family level, Enterobacteriaceae and Moraxellaceae were dominant in the early instar group, and Anaplasmataceae was dominant in the diapause prepupa group. At the genus level, Enterobacter and Acinetobacter were dominant in the early instar group, and Wolbachia was dominant in the diapause prepupa group. The results of functional gene annotation also showed the characteristics of the three groups. 【Conclusion】 There are significant differences in the community structure of gut bacteria in different instar larvae and diapause prepupae of C. gigas. The bacterial diversity decreases gradually from the early instar group to the late instar group and then to the diapause prepupa group, and this may be related to the feeding characteristics and adaptation of gut microorganisms to the gut environment. This study lays a foundation for the study of gut microorganisms of soil-nesting wild bees and also provides a new angle and direction for the protection of this kind of wild bees.

【Aim】 Raspy crickets (Orthoptera: Gryllacrididae) are a unique group in the Orthoptera, and they produce silk and use it to build shelters. The purpose of this study is to investigate the structural characteristics of their silk glands. 【Methods】 The fine structure and ultrastucture of silk glands of Capnogryllacris nigromarginata were observed by anatomy observation, immunofluorescence, hematoxylin-eosin staining, PAS-hematoxylin staining, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). 【Results】 The silk glands of C. nigromarginata are composed of acini and silk ducts. Each acinus is composed of a fibrous sheath enclosing four main types of cells: type Ⅰ secretory cells, type Ⅱ secretory cells, peripheral cells and canal cells. Type Ⅰ and Ⅱ secretory cells are large glandular cells in irregular shape. The secretory cells have large nuclei. The cytoplasm of secretory cells is characterized by containing abundant endoplasmic reticulum and secretory particles. Type Ⅰ secretory cells are near the center of acinus. PAS-hematoxylin staining showed that type Ⅰ secretory cells contain glycoprotein. Type Ⅱ secretory cells are at the peripheral region of acinus located between type Ⅰ secretory cells and peripheral cells or sheath cells. The canal cells are scattered between the secretory cells and form the extracellular transport canal of secretion. In contact with the sheath cells, peripheral cells have microvilli cavity formed by cell membrane invagination, and there are a large number of mitochondria in the cytoplasm. The microvilli cavity is connected to an extracellular canal surrounded by canal cells. Secretory particles are accumulated at the junction of the secretory cells and the extracellular transport canal. Then they discharge secretions to the extracellular transport canals. The extracellular canals of multiple acini converge to the silk duct composed of a single layer of cells. The cell periphery of the silk duct is involved in the organization of a series of deep invaginations of the plasma membrane. A large number of elongated mitochondria can be observed around the cell plasma membrane invaginations. The apical border of the silk duct cell near the inner lumen has continuous membrane processes that are closely aligned under the cuticle of the duct wall. 【Conclusion】 The secretory cells of silk glands of C. nigromarginata can be divided into type Ⅰ and type Ⅱ secretory cells. The production and secretion process of secretory materials in turn pass through secretory cells, extracellular canals of canal cells, branch ducts, common duct of silk glands, and salivarium. When the secretions are transported outward from the extracellular canal surrounded by the canal cells, the microfilaments in the microvilli cavity of peripheral cells may provide impetus for the excretion of secretions.

【Aim】The objective of this research is to explore the effects of DOPA decarboxylase (DDC) on fecundity in the multicolored Asian beetle, Harmonia axyridis, and its regulatory mechanism. 【Methods】RNA interference (RNAi) was used to suppress the expression of DDC gene ( HaDDC) in the 4th instar larvae of H. axyridis, and the cumulative number of eggs laid in 20 d was counted from the 8th day after adult emergence and the egg hatching rate of offspring was recorded on the 3rd day after egg laying. Then the ovaries of female adults of H. axyridis were dissected, the ovarian tissue morphology and the number of ovarioles of the 8-day-old adults between the treatment group (injected with ds HaDDC) and the control group (injected with ds GFP), and the development of eggs in the ovarioles of the 14- and 20-day-old adults between the treatment group and the control group were observed and recorded.【Results】After the expression of HaDDC gene of both sexes of H. axyridis was inhibited by RNAi, the cumulative number of eggs laid by adults in 20 d was 38.67±7.80, which was significantly lower than that of the control group (371.33±84.31). After the expression of HaDDC gene in female and male adults was inhibited, the cumulative numbers of eggs laid in 20 d were 135.50±28.38 and 76.00±14.00, respectively, which were significantly different from that of the control group. The egg hatching rate of offspring was 0 when the expression of HaDDC gene in both sexes was inhibited. On the 8th day after emergence of H. axyridis, the ovarian tissue morphology and the number of ovarioles in the treatment group were not significantly different from the control. On the 14th day after adult emergence, the ovaries of H. axyridis were plump, and the oocytes were developed in the bilateral ovarioles. However, compared with the control group, no mature eggs were found in the treatment group.【Conclusion】Based on the above results, we can preliminarily conclude that DDC can regulate the fecundity of H. axyridis by participating in the development process from oocyte to mature eggs.

【Aim】 Ascosphaera apis is a fungal pathogen that infects Apis mellifera ligustica larvae and causes chalkbrood in honeybee colonies. This study aims to investigate the effects of A. apis infection on the expression of genes related to intestinal immunity and detoxification and the contents of proteins, lipids and carbohydrates in the gut of A. m. ligustica larvae, and to analyze the relationship between the immune response and nutrients of A. m. ligustica under A. apis infection. 【Methods】 The A. m. ligustica larvae were raised in the laboratory. Each 3-day-old larva was inoculated with 2×10 ⁶ spores/mL of A. apis in the treatment group, and that in the control group was fed with the normal food. Then, the gut samples of 6-day-old larvae were collected. The expression levels of genes related to immune, detoxification and development and genes of pathogens in the gut samples were detected by qRT-PCR, and the contents of proteins, lipids, glucose, and glycogen in the gut samples were determined by biochemical methods. 【Results】 After A. apis infection, the expression levels of immune-related genes LOC406144, Apid1, Def1, Def2, LOC406142, PGRP-SA, Pgrp-s2, PGRP-S3, PGRP-lc, GNBP-1, GNBP3, PPOact, LOC552247, domeless, KAT2A and bsk in the larval gut of A. m. ligustica were significantly up-regulated and that of cactus was significantly down-regulated. The expression levels of detoxification-related genes Cat, GSTS3, Cyp4g11, LOC725294, Ampka- r1, LOC411223, LOC409791, AmNOS and Sod2 in the larval gut of A. m. ligustica infected by A. apis were significantly up-regulated and those of CYP6AS14, CPR14, CYP306A1 and LOC100576555 were significantly down-regulated. The expression level of development-related gene usp in the larval gut of A. m. ligustica infected by A. apis was significantly up-regulated and those of VGMC, HEX70b and Vg were significantly down-regulated. The expression levels of pathogen genes BQCV capsid protein and Ascosphaera apis 28S rRNA in the larval gut of A. m. ligustica infected by A. apis were significantly up-regulated. The contents of proteins and lipids in the larval gut of A. m. ligustica infected by A. apis were significantly down-regulated, and those of glucose and glycogen were significantly up-regulated. 【Conclusion】 The A. apis infection influences the expression of genes related to immune, detoxification and development and genes of pathogens in the gut of A. m. ligustica larvae, affecting the immune response and energy stress response and accelerating the loss of proteins and lipids and the energy reservation of glucose and glycogen, and these may result in abnormal physiological activities of A. m. ligustica larvae.

【Aim】 This study aims to explore the role of heat shock protein 70 (HSP70) genes in the process of resisting high temperature stress and to provide a theoretical basis for revealing the expansion mechanism of Hyphantria cunea and predicting its potential distribution area. 【Methods】 HSP70 genes of H. cunea were cloned by PCR and subjected to bioinformatical analysis. The expression characteristics of HSP70 genes in the day-2 4th instar newly molted larvae of H. cunea under 25, 30, 35 and 40℃ were detected by qPCR. The prokaryotic expression vector of HSP70 of H. cunea was constructed and induced to express in Escherichia coli BL21. The protein was purified by Ni ²⁺-His column and verified by Western blot. Then, the ATPase activity of the recombinant protein obtained by prokaryotic expression was determined by in vitro experiments. 【Results】 The two HSP70 genes of H. cunea including HcHSP70 (GenBank accession no.: MT995848) and HcHSC70 (GenBank accession no.: MT261583) were cloned and sequenced. Their ORFs are 1 917 and 2 061 bp in length, encoding 637 and 687 amino acids with the predicted molecular weights of about 69.66 and 74.96 kD, and the isoelectric points of 5.90 and 5.96, respectively. The structure prediction conformed to the characteristics of the heat shock protein 70 family, which contains three highly conserved regions GIDLGTTYS, IFDLGGGTFDVSIL, and VGGSTRIPKVQ. The 3D structure of the two HSP70 proteins is composed of the N-terminal ATPase functional domain and C-terminal substrate binding domain. The phylogenetic tree showed that HcHSP70 and other members of the HSP70 family of Lepidoptera were clustered into one branch, while HcHSC70 and other members of the HSC70 family of Lepidoptera were clustered into another branch. The qPCR results showed that the expression of HcHSP70 in the day-2 4th instar newly molted larvae of H. cunea was significantly upregulated under heat stress and reached the peak under 35℃ for 2 h, while HcHSC70 had a weak expression response under heat stress. The prokaryotic expression vector of HcHSP70 was successfully constructed, and HcHSP70 was expressed in vitro. The purified recombinant protein HcHSP70 had ATPase activity, which was stable under high temperature stress. 【Conclusion】 In this study, HcHSP70 and HcHSC70 of H. cunea were cloned, and their expression characteristics under high temperature were confirmed. The prokaryotic expression and purification of HcHSP70 were successfully performed. The recombinant HcHSP70 has stable ATPase activity under high temperature, suggesting that it may play an important role in the response of H. cunea to high temperature stress.

 Mythimna loreyi is a relative species of Mythimna seperata. The two pest species are similar in morphology and have basically the same damage characteristics, but there may be some differences in the occurrence and damage rules in different regions. In recent years, M. loreyi has become a common agricultural pest with frequent outbreaks in many countries and regions. In order to deeply study the outbreak law and to comprehensively prevent and control this pest, we summarized its research status based on the analysis of domestic and foreign research data in this article. At present, M. loreyi has been distributed in nearly 80 countries and regions in Asia, Europe, Africa, Oceania and North America. The larvae of this pest feed on a variety of gramineous crops and weeds, such as corn, rice and wheat. Before the 3rd instar, the larvae eat less, the 5th-6th instar larvae eat more, and enter the gluttony stage. The larvae of M. loreyi are aggregative, omnivorous and gluttonous, and the adults are migratory. The damage caused by this pest is covert, sporadic and fulminant. There are differences in the law of the occurrence and damage of M. loreyi due to different regions, years and seasons. Climatic conditions, food and natural enemies are the main factors that affect its damage. At the same time, it is pointed out that climatic factors, human activities and the biological characteristics of M. loreyi are the important factors that have led to its occurrence expansion and damage aggravation in recent years. Sex attractants, natural enemies and biological pesticides are the main research directions in the biological control of this pest in recent years. Based on the occurrence and research status of M. loreyi in China, the following three aspects are suggested to be carried out in the future work: (1) By learning from the prevention and control strategies and experience of M. seperata, strengthening the prediction and forecast of M. loreyi from two aspects of air forecast and ground forecast; (2) carrying out comprehensive prevention and control work from agricultural control, physical control, biological control and chemical control; and (3) applying modern technologies and methods such as biotechnology and modern agricultural information technology to study the law of outbreak and disaster, integrated prevention and control of M. loreyi, and to establish the comprehensive prevention and control technology systems.

 【Aim】 Monolepta hieroglyphica is a polyphagous pest feeding on a large number of cultivated plant species. The aim of this study is to investigate the genetic diversity, genetic structure, and levels of genetic differentiation and gene flow among geographical populations of M. hieroglyphica distributed in South China, and to clarify the diversity and prevalence of the bacterial endosymbiont Wolbachia in M. hieroglyphica geographical populations in South China. 【Methods】 The mitochondrial COII gene was used as genetic marker. The partial COII gene sequences in a total of 403 individuals from 14 geographical populations of M. hieroglyphica were amplified by PCR and sequenced. The haplotype diversity ( Hd), genetic differentiation coefficient ( F _st) and gene flow ( Nm) between populations were analyzed, and the analysis of molecular variance (AMOVA) and Tajima’s D and Fu’s Fs neutrality tests were performed. Median-joining network and phylogenetic tree were constructed based on haplotype sequences. Wolbachia wsp gene was amplified by PCR to detect population infection rates, and the obtained wsp sequences were used for strain typing and phylogenetic analysis of Wolbachia. 【Results】 For all the 403 test individuals of M. hieroglyphica in this study, 23 COII haplotypes were observed and divided into two clusters in phylogenetic tree. The Hd of total population was 0.748, ranging from 0.394 to 0.782 within each population. The neutrality test results suggested that M. hieroglyphica populations followed the neutral evolution model and there was no evidence of population expansion in recent history. The values of F _st and Nm of total population were 0.2481 and 0.76, respectively. The AMOVA results showed that a high proportion (73.75%) of the total genetic variance attributed to variation within population. There was no significant correlation between genetic distance and geographical distance among populations ( R=0.2898, P=0.0640). The Wolbachia infection rates in the 14 geographical populations of M. hieroglyphica ranged from 92.59% to 100%, with an average infection rate of 97.60%. Six Wolbachia strains (named as wMhie1- wMhie6) were identified based on wsp sequences, and these strains all belong to the supergroup A, which is clearly distinguished from other representative stains and forms a unique cluster in the phylogenetic tree. 【Conclusion】 The genetic diversity of M. hieroglyphica populations distributed in South China is comparatively high. There is significant genetic differentiation among most populations and the gene flow is low among populations. No significant correlation exists between genetic differentiation and geographical isolation. High infection rates and diversity of Wolbachia exist in M. hieroglyphica populations in South China.

 【Aim】This study aims to clone and identify odorant-binding protein (OBP) genes in the adzuki bean seed weevil, Callosobruchus chinensis and to assay their tissue-specific expression profiles in C. chinensis adults, so as to to lay a foundation for studying the function of OBPs in olfactory perception in C. chinensis. 【Methods】Based on the antenna transcriptome data of C. chinensis, six OBP genes in C. chinensis were cloned by RT-PCR and analyzed by bioinformatics. The expression levels of OBP genes in tissues including head (excluding antennae), antennae, abdomen, legs and wings of female and male adults of C. chinensis were analyzed by qRT-PCR. 【Results】 The open reading frames of six OBP genes from C. chinensis were obtained, and named as CchiOBP1-CchiOBP6 (GenBank accession number: MN832700-MN832703, MN901841-MN901842). CchiOBP5 is a segment of Minus-C OBP with incomplete C-terminus, and the others belong to complete classical OBPs. It was predicted that all the six CchiOBPs contain signal peptides. Phylogenetic analysis showed that CchiOBP1, CchiOBP2 and CchiOBP5 were closely related to OBPs of Chrysomelidae, and CchiOBP3, CchiOBP4 and CchiOBP6 were closely related to OBPs of Cerambycidae. The qRT-PCR results showed that six CchiOBP genes were differentially expressed in the antennae, head (excluding antennae), abdomen, wings and legs of C. chinensis adults. CchiOBP1-4 and CchiOBP6 were highly expressed in antennae of female and male adults of C. chinensis, and their expression levels in antennae were extremely significantly higher than those in the other adult tissues. CchiOBP5 was highly expressed in female antennae and head (excluding antennae), but in males it showed significantly higher expression level in legs than in other adult tissues, with the lowest expression level in antennae. 【Conclusion】 The nucleotide and amino acid sequences of six CchiOBP genes of C. chinensis have been determined, among which five CchiOBP genes are highly expressed in the antennae of female and male adults of C. chinensis, suggesting their important roles in olfactory recognition of host plants.

【Aim】 To enrich the knowledge of the anticancer mechanism of antimicrobial peptide HI-3 extracted from Hermetia illucens by studying the effects of HI-3 on the amino acid metabolism of human colon carcinoma HCT-8 cells. 【Methods】 CCK-8 assay was used to determine the inhibition rates of different concentrations (80, 160, and 320 μg/mL) of antimicrobial peptide HI-3 on HCT-8 cells. The metabolites in HCT-8 cells were determined by GS-MS, and then the metabolic pathway with the most significant difference in amino acid contents and the target enzyme in this pathway were screened by pathway analysis based on R software. After the HCT-8 cells were treated with 320 μg/mL HI-3, the activity of the selected target enzyme glutaminase (GLS) was assayed by enzyme activity kit, its mRNA and protein expression levels were detected by RT-qPCR and Western blot, respectively, and the changes in the contents of important metabolites including glutamine (Gln), glutamic acid (Glu), glutathione (GSH), α-ketoglutaric acid (α-KG) and ATP involved in the glutamine and glutamic acid metabolic pathway in HCT-8 cells were detected by biochemical kits and ELISA kit. 【Results】 The inhibition rates of HCT-8 cells treated by HI-3 at the concentrations of 80, 160, and 320 μg/mL were 33.85%  ±3.50%, 46.26%±0.90%, and 55.53%±1.70%, respectively, and the inhibition rates increased with the increase of the HI-3 concentration. HI-3 at the concentration of 320 μg/mL showed the greatest effects on the glutamine and glutamic acid pathway with the contents of amino acid metabolites in this pathway most significantly different from those in the negative control group (0 μg/mL HI-3). The activity of GLS (the target enzyme in this pathway) and the mRNA and protein expression levels of its gene GLS in the 320 μg/mL HI-3 treatment group were extremely significantly lower than those in the negative control group. Moreover, the contents of important metabolites in this pathway, including Gln, Glu, GSH, α-KG and ATP, in the 320 μg/mL HI-3 treatment group were also significantly reduced as compared with those in the negative control group. 【Conclusion】 Antimicrobial peptide HI-3 from H. illucens at the concentration of 320 μg/mL has the most significant effect on the glutamine and glutamic acid metabolic pathway in HCT-8 cells, and can significantly inhibit the proliferation of HCT-8 cells by blocking this pathway.

【Aim】 To identify LY domain-containing trypsin (LY-trypsin) genes of Anopheles sinensis at the whole genome, and to explore their molecular characteristics, expression patterns and phylogentic relationships. 【Methods】 The amino acid sequences encoded by trypsin genes in An. gambiae, Aedes aegypti, Drosophila melanogaster, and Culex quinquefasciatus were downloaded from NCBI databases and used as queries to search for trypsin genes in An. sinensis genome using the local Blast program. LY-trypsin genes in An. sinensis were named based on domain characteristics and phylogenetic relationship. The structure, scaffold location, structural domain and phylogenetic relationships of LY-trypsin genes of An. sinensis, and their expression patterns at different developmental stages of An. sinensis, in different adult tissues of An. sinensis, and in female adults of An. sinensis before and after blood feeding were predicted using bioinformatics analysis. 【Results】 Twenty-seven LY-trypsin genes were identified in the whole genome of An. sinensis, while no LY-trypsin gene was identified in D. melanogaster, An. gambiae, C. quinquefasciatus, and A. aegypti. The 27 LY-trypsin genes of An. sinensis encode 329-1 125 amino acids, with the molecular weight of 36.8-125.5 kD, and pI of 4.73-8.94. Among them 20 LY-trypsin proteins have signal peptides, with their length ranging from 10 to 62 aa. The numbers of exons of the 27 LY-trypsin genes of An.sinensis range from one to five, and the length of introns ranges from 62 to 20 093 bp. The 27 LY-trypsin genes of An.sinensis are mapped on 11 scaffolds, their encoded proteins all have a conserved YWTD motif (LY motif), and the amino acid sequences encoded by 16 LY-trypsin genes of the 27 LY-trypsin genes have the active site containing the catalytic triad of serine, histidine and aspartic acid. Phylogenetic results showed that the 27 LY -trypsin genes of An. sinensis clustered into four branches. At different developmental stages, more than 50% of the LY-trypsin genes of An. sinensis showed similar expression patterns and were expressed at high levels during the larval stage. LY-trypsin genes were expressed in different adult tissues of An. sinensis. Only a few of LY-trypsin genes were expressed in female adults of An. sinensis before and after blood feeding without expression specificity. 【Conclusion】 In this study, LY-trypsin genes have been identified in the genome of An. sinensis for the first time, and the molecular characteristics and expression patterns of the LY-trypsin genes have been investigated. This study provides an information framework for the further study of LY-trypsin genes.

【Aim】 This study aims to test the applicability of four analytical methods,  including automatic barcode gap discovery (ABGD), generalized mixed Yule coalescent (GMYC),  Bayesian Poisson tree processes (bPTP), and Bayesian phylogenetics and phylogeography (BPP)  with fragments of two genes, mitochondrial COI and nuclear CAD, in the molecular species  definition of Meloidae insects. 【Methods】 Eighteen meloid morphologic species widely  distributed in northern China and belonging to six genera (Hycleus, Mylabris, Epicauta,  Lytta, Megatrachelus, and Meloe) were sampled. The molecular species definition was carried  out based on COI, CAD, and concatenated COI+CAD sequence data sets by using ABGD, GMYC,  bPTP, and BPP. The molecular species definition results by using different methods were  compared with that by the morphological identification, respectively. 【Results】 The  molecular species definitions based on the COI+CAD concatenated sequence data sets were  consistent with the morphological identification results, those based on COI sequences with  the ABGD and GMYC methods were also consistent with the morphological identification  results, while the number of species identified by using bPTP was more than that by  morphological identification. The definition results based on CAD sequences by using all  three single-gene species definition methods except GMYC were partially different from the  morphological identification results. 【Conclusion】 The molecular species definitions of  Meloidae based on multi-gene concatenated sequences and multiple methods are better than  those based on single gene fragment or single definition method. The results of this study  provide data support and reference for molecular species definition and integrative  taxonomy of the family Meloidae.

【Aim】 Aminopeptidases N (APNs) are a class of important proteases in the digestive system in insects. This study aims to verify the expression of two apn genes ( nlapn1 and nlapn4) with high transcription level in the midgut epithelium of the brown planthopper, Nilaparvata lugens, and to identify and analyze the characteristics of their proteins. 【Methods】 Phylogenetic analysis of both NLAPN1 and NLAPN4 of N. lugens was conducted by maximum likelihood method. Western blotting and LC-ESI-MS/MS were respectively conducted to localize and identify NLAPN1 and NLAPN4 in the midgut brush border membrane vesicles (BBMVs) of N. lugens. NLAPN1 and NLAPN4 were respectively expressed in Drosophila S2 cells. Lacolization of both NLAPN1 and NLAPN4 in S2 cells was analyzed by Western blot and immunofluorescence. The enzymatic activities of NLAPN1 and NLAPN4 were determined through enzyme assays using leucine- p-NA, Ala- p-NA, Met- p-NA and Lys- p-NA as the substrate, respectively. 【Results】 Phylogenetic tree analysis showed that both NLAPN1 and NLAPN4 of N. lugens were clustered together with the APN proteins highly expressed in the midgut of other hemipteran insects. NLAPN1 and NLAPN4 with the molecular weight of ~160 kD were identified in the midgut BBMV of N. lugens by Western blot and LC-ESI-MS/MS. Western blot and immunofluorescence analysis showed that NLAPN1 and NLAPN4 were expressed on the cytomembrane of transfected S2 cells, while that of NLAPN4lackG without glycosylphosphatidylinositol (GPI) anchor site at the C-terminal end was distributed in the cytoplasm. Enzyme assay results revealed that both NLAPN1 and NLAPN4 showed certain enzymatic activity using Ala- p-NA and Lys- p-NA as the substrate, while using leucine- p-NA as the substrate, NLAPN1 showed extremely high enzymatic activity (＞60 U/mg). 【Conclusion】 NLAPN1 and NLAPN4 are both highly expressed GPI-anchored membrane-bound aminopeptidases N located on the epithelial membrane of the midgut of N. lugens. Both NLAPN1 and NLAPN4 show similar structure and enzymatic characteristics to the previous identified membrane-bound APN proteins in lepidotperans, coleopterans and dipterans. Physiological and biochemical functions of membrane-bound APNs in the midgut of N. lugens and their interaction with exogenous pathogenic microorganisms need to be further studied.