【Aim】To understand the effects of habitat changes on the bacterial communities in the larval gut of chironomids by studying the diversity and potential function of bacterial communities in the gut of Propsilocerus akamusi, a pollution-resistant chironomid identified in the freshwater area of the heavy metal polluted Bohai Bay of Tianjin City. 【Methods】The 4th instar larvae of P. akamusi identified in the freshwater area of the heavy metal polluted Bohai Bay of Tianjin City were raised with distilled water in laboratory for 7 d as the laboratory-cultured group, and the bacterial genomic DNA in the 4th instar larval gut of P. akamusi from the laboratory-cultured group and the wild-captured group was extracted. The high-throughput sequencing of the V3-V4 region of 16S rRNA gene was carried out, and the sequencing results were subjected to data quality control, sequence alignment and filtering, the changes in the species composition of gut bacterial communities were analyzed and the potential functions of gut bacteria were predicted. 【Results】Based on the 16S rRNA sequencing results of the gut bacteria in the 4th instar larvae of P. akamusi, 11 phyla, 13 classes, 33 orders, 54 families, 71 genera, 90 species and 105 operational taxonomic units (OTUs) were annotated. The diversity and abundance of bacterial communities in the 4th instar larval gut of P. akamusi in the laboratory-cultured group were lower than those in the wild-captured group. The dominant bacterial phyla in the 4th instar larval gut of the two groups were similar, including Firmicutes, Proteobacteria, Bacteroidota and Desulfobacterota. The abundance of Proteobacteria in the 4th instar larval gut of the wild-captured group was significantly higher than that in the laboratory-cultured group. The average abundance of Aeromonas, Shewanella, Serratia, Pseudomonas and Yersinia in the 4th instar larval gut in the laboratory-cultured group was significantly lower than that in the wild-captured group. The results of linear discriminant analysis revealed that there were bacterial species with significantly different abundance in the 4th instar larval gut of P. akamusi between the wild-captured group and the laboratory-cultured group. The KEGG analysis results showed that the relative abundance of metabolism-related genes in the bacterial genome of the 4th instar larval gut of P. akamusi was extremely high. The relative abundance of genes related to environmental information processing and cellular processes in the gut bacterial genome of the 4th instar larva of P. akamusi in the laboratory-cultured group significantly decreased as compared to that in the wild-captured group.【Conclusion】The results of this study indicate that there are significant differences in the diversity of the gut bacterial communities and gene functions between P. akamusi larvae living in adverse field environments and those reared in laboratory pure water environments. This helps to study the individual resistance mechanisms of chironomids from an environmental perspective, provides a new idea for further exploring the mechanism of the symbiotic microorganisms in the gut of chironomid larvae to cope with environmental stress, and also lays a foundation for the study of the tolerance mechanism of insects in adverse environmental conditions and the regulatory mechanism of homeostasis of their gut microbial communities.

 【Aim】 The objective of this study is to explore the role of Kazal-type serine protease inhibitor KaSPI in the development, digestion, and immune defense processes of the soybean aphid, Aphis glycines. 【Methods】 The cDNA sequence of Kazal-type serine protease inhibitor gene from A. glycines was cloned by PCR based on the transcriptome data of A. glycines. qRT-PCR was used to detect the expression levels of AgKaSPI in the 1st-4thinstar nymphs and adults of A. glycines, and in A. glycines adults at 3, 6, 12, 24, 48 and 72 h after infection by Akanthomyces lecanii. After RNAi of AgKaSPI with siRNA for 3, 6, 12, 24 and 48 h, the RNAi efficiency was detected by qRT-PCR, and the mortality and fecundity of A. glycines adults at 12, 24, 48 and 96 h post RNAi were recorded. The AgKaSPI content and the activities of serine protease, trypsin and chymotrypsin in A. glycines adults were detected by double antibody sandwich method after infection by A. lecanii and RNAi of AgKaSPI. The mortality of A. glycines adults at 12, 24, 48 and 96 h after infection by A. lecanii following RNAi of AgKaSPI for 6 h was observed and recorded. 【Results】 The cDNA sequence of a serine protease inhibitor gene AgKaSPI (GenBank accession no. MK440557) was cloned from A. glycines. AgKaSPI is 1 019 bp in length, with the open reading frame of 324 bp, encoding 107 amino acids. AgKaSPI has the Kazal domain, with the molecular weight of 11.43 kD and isoelectric point of 9.24. AgKaSPI was expressed at different developmental stages of A. glycines. At 24 h after infection by A. lecanii, the expression level of AgKaSPI and the corresponding AgKaSPI content in A. glycines adults were significantly up-regulated, being 4.31-fold and 1.69-fold as high as those of the control group, respectively, while the activities of serine protease, trypsin and chymotrypsin were inhibited. At 6 h after RNAi of AgKaSPI, the expression level of AgKaSPI in A. glycines adults decreased by 71.05%. The KaSPI content decreased by 51.11% and the activities of serine protease and chymotrypsin increased significantly at 12 h after RNAi of AgKaSPI. The fecundity per one hundred individuals decreased by 49 born aphids and the mortality of A. glycines adults increased by 10.12% at 96 h after RNAi of AgKaSPI. 【Conclusion】 AgKaSPI is expressed at different developmental stages of A. glycines, and the expression level of AgKaSPI is significantly up-regulated at 24 h after infection by A. lecanii. AgKaSPI may participate in the immune response of A. glycines to A. lecanii infection by regulating the serine protease activity.

 The development of gene editing technology is of great significance for the study of physiological functions such as growth, development and reproduction of insects, as well as the mechanism of behavior manipulation. In this article, we introduced the development history of gene editing technology, and described the principles of zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) protein 9 (CRISPR/Cas9) system-mediated gene site-editing technologies. In the model insect Drosophila, the third-generation gene editing technology is continuously upgraded and optimized. It has such advantages as high editing efficiency, heritability, and facilitating screening, which helps to reveal the mechanism of key signal pathways in cell biology, developmental biology and neurobiology. In the medical vector insect mosquito, the CRISPR/Cas9 system-mediated gene editing technology has important research value in reducing pesticide resistance, and controlling the population and epidemic spread of mosquito-borne diseases. In the study of agricultural pests, the use of gene editing technology can perform the in vivo functional characterization of the key molecular targets in multiple signaling pathways, providing a new idea for pest management. In the study of beneficial insects, gene editing technology is mainly applied to studying sex regulation and antiviral ability of Bombyx mori, and improving silk quality. Finally, we debate the future prospects for the study of the gene editing technology in insects: (1) to optimize gene editing systems to improve editing efficiency; (2) to develop new gene regulation tools; and (3) to construct transgenic insect strains, in order to provide references for the analysis of insect gene function, the improvement of economic insects, and the control of major pests.

 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】This study aims to preliminarily clarify the molecular mechanism of  diapause in Gomphocerus sibiricus eggs through screening diapause genes and metabolic  pathways of the eggs.【Methods】 Transcriptome sequencing was performed on G. sibiricus  eggs at different developmental stages ［early developmental stage (ES), diapause stage  (DS), and post-diapause developmental stage (PS)］, with the Illumina NovaSeq 6000  sequencing platform. The diapause-associated pathways of G. sibiricus eggs were predicted 
by GO and KEGG enrichment analysis, and analyzed by cluster heat map analysis combined with  literature reports to screen diapause-associated genes. qRT-PCR was used to verify six  important genes of the screened diapause-associated genes. 【Results】 In the DS vs ES and  PS vs DS comparative groups, 12 419 and 4 789 differentially expressed genes (DEGs) were  enriched, respectively, and most of them were up-regulated. A total of 2 206 DEGs of the  two comparative groups were mainly related to glucose metabolism, environmental stress and  growth and development. The most significant enrichment of GO items in the DS vs ES group  was protein binding. The GO items in the PS vs DS group mainly included enzymatic activity,  cytoskeleton construction and protein binding. Diapause-associated genes were mainly  involved in Wnt signaling pathway, insulin signaling pathway, cell cycle pathway and insect  hormone biosynthesis pathway. The expression trends of the six important  diapause-associated genes were consistent with the transcriptome data. 【Conclusion】 In  this study, important metabolic pathways that regulate diapause of G. sibiricus eggs were  preliminarily identified, and a total of 20 diapause-associated genes were screened out,  laying a foundation for further study on the adaptation mechanism of this species.

Insect symbionts are microorganisms that establish enduring and sustained associations with insect hosts. These microorganisms inhabit the body surface, gut, hemocoel, or intracellular cells of insects, participating in the regulation of various physiological functions of their host insects. Research on insect-symbiont interactions involves multidisciplinary collaboration. In-depth exploration of the functions of insect symbionts and their interactions with hosts not only advances our understanding of fundamental mechanisms in the life sciences but also introduces innovative perspectives and methods for pest management, vector-borne disease control, and optimal utilization of beneficial insects. In recent years, Chinese researchers have made noteworthy progress in the insect microbiome and got significant achievements in many research directions. In this article, we provided an overview of the most recent research progress in insect symbionts, introduced the main contents of this special issue, and proposed three noteworthy research directions: (1) the functions of insect intracellular symbionts; (2) the mechanisms by which insects regulate the abundance and transmission of symbionts; and (3) genetic modification and application of insect symbionts.

【Aim】 To reveal the relationship between the feeding of Bt proteins by  Spodoptera frugiperda larvae and the changes in the expression levels of related ABC (ATP- binding cassette transporter) genes in the midgut. 【Methods】 Artificial diets containing  Cry1Ab (LC₇₀=240.2 μg/g) or Cry1Fa (LC₇₀=270.0 μg/g) activated crystal protein were  used to feed the 4th instar larvae of S. frugiperda for 48 h, respectively. Transcriptome  sequencing of midgut and bioinformatics analysis were used to screen differentially  expressed genes in the midgut after treatment. RT-qPCR was used to verify the expression  levels of the differentially expressed ABC genes. 【Results】 A total of 1 305 and 1 202  differentially expressed genes were detected in the midgut transcriptome of the 4th instar  larvae of S. frugiperda fed with the artificial diet containing 240.2 μg/g Cry1Ab and  270.0 μg/g Cry1Fa, respectively, compared with those fed with the normal artificial diet  (the control group). There were 994 and 912 differentially expressed genes between the  Cry1Ab and Cry1Fa treatment groups and the control group, respectively, and were annotated  by GO function into three categories biological process, molecular function and cell  component. Among the nine differentially expressed ABC family genes screened, there were  four differentially expressed ABC genes (three up-regulated and one down-regulated)  between the Cry1Ab treatment group and the control group and five differentially expressed  ABC genes (two up-regulated and three down-regulated) between the Cry1Fa treatment group 
and the control group. The expression levels of two ABC genes (LOC118267200 and  LOC118267201) in the Cry1Ab and Cry1Fa treatment groups were significantly up-regulated as  compared to those in the control grpup. RT-qPCR validation results showed that the  expression levels of three and two ABC genes in the Cry1Ab treatment group were extremely  significantly up-regulated and down-regulated, respectively, and those of five ABC genes  and one ABC gene in the Cry1Fa treatment group were up-regulated and down-regulated,  respectively, as compared to those in the control grpup. 【Conclusion】 The intake of  Cry1Ab and Cry1Fa proteins could affect the expression levels of certain ABC family genes  in the midgut of S. frugiperda larvae, and the expression level changes of these genes are  related to pest resistance. After comparison, we found that the expression levels of ABCC  family and ABCG8 genes changed significantly. This study provides a theoretical basis for  further clarifying the role of ABC transporter proteins in the insecticidal mechanism of Bt  proteins in S. frugiperda and the rational use of Bt proteins for controlling S. frugiperda  and delaying resistance.

 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.

 Confronted with herbivores, plants have evolved a sophisticated network of defense, which can be classified as constitutive and induced. After perceiving herbivore-derived molecular via receptors, the tea plant (Camellia sinensis) will initiate early signaling events, and then activate multiple signaling pathways of plant pheromones, such as jasmonic acid (JA), salicylic acid (SA), ethylene (ET), gibberellin and other phytohormones, resulting in the accumulation of secondary metabolites, and eventually induce direct and indirect resistances to pests. Based on the recent research progress in tea plant defense responses induced by main insect pests and their regulatory mechanisms, we summarized the components and ecological functions of herbivore-induced plant volatiles (HIPVs) of the tea plant, and their application in green pest control, uncovered the important defense signaling network involved in the regulation of insect-induced resistance in the tea plant, emphasized on the research progress of the JA pathway in the tea plant, and proposed suggestions for future research. The infestation of Ectropis obliqua, Matsumurasca onukii and Myllocerinus aurolineatus induces 17 shared volatiles from tea plants, but induces eight, three and two specific volatiles from tea plants, respectively. Among the above volatiles, five, one and six volatiles were found to have attractiveness to E. obliqua, M. onukii and M. aurolineatus, respectively, while two volatiles and one volatile are involved in the repellence against E. obliqua and M. onukii, respectively. Thus, the attractants to these three insect species and the repellents against M. onukii have been screened out. The JA pathway and SA pathway are the two main pathways involved in the defense responses in tea plants to multiple insect pests, and the JA pathway plays a vital role. Meanwhile, several plant hormones, including auxin, abscisic acid, gibberellin, etc., also take part in tea plant induced defense processes. So far, many genes associated with JA biosynthesis and regulation have been cloned and characterized. Based on the understanding of their functions in tea plant resistance against insects, the fact that JA pathway positively regulates direct or indirect tea plant resistance to insects was revealed. We suggest that the further study should focus on further clarifying the molecular mechanisms of insect-induced resistance in the tea plant, and the utilization of induced defense against insect pests in tea plants. This article will provide guidance for in-depth research on the molecular mechanisms in induced resistance in the tea plant and further development of green pest prevention and control technologies.

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.

 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?

 As one of the important branches of entomology, insect development and immunity, facing the national demand and scientific frontier, has made great achievements in solving major pest disasters and human health through multidimensional research. Meanwhile, the progress of new biotechnology has greatly promoted the research of insect development and immunity by deepening and widening our understanding of insect development and immune defense. Articles in this special issue of “Insect growth and development and immunity” reflect well the current status and features of research on insect development and immune in China. The growth and development part covers all developmental stages from egg to adult, mainly focusing on the signal transduction, and the immunity part focuses on biological interactions. In the context of big data, more efforts will be made to combine traditional and modern techniques, and strengthen cooperation, thus making the research branch play a greater role in pest control, insect resource utilization, and food security.

Successfully locating a host is one of the crucial steps in parasitoid  reproduction, which is regulated mainly by volatile compounds. Firstly, female parasitoids  often use volatiles from host plants, especially herbivore-induced plant volatiles  (HIPVs), to locate the habitat of their hosts at long distances, which helps female  parasitoids narrow their host searching range according to the cues provided by HIPVs. The  blends of HIPVs are extremely complicated, and their components and contents can be  modulated by a wide range of factors. Nevertheless, terpenoids are common compounds in  HIPVs and have been confirmed by most behavioral studies to play a role in host  localization of parasitoids. Subsequently, when the parasitoids find a plant related to  hosts and land on them, they exploit host-derived cues at a close range to locate hosts.  Parasitoids are usually attracted to volatile compounds released from the host body,  cocoon, feces, etc. The odor of some host feces can be used as the main cues for  parasitoids to locate hosts. Moreover, the components of volatiles in host feces may vary  among plant species which insects feed. In addition, semiochemicals from the parasitoid  itself are also beneficial for other individuals of the same species to locate their hosts.  Sensory perception of odor molecules by parasitoids relies on olfactory sensilla, primarily  located on the antennae, but the research on the molecular mechanism of their olfactory  recognition is still limited. Because odorant-binding proteins (OBPs) are the crucial  proteins in the olfactory system that mediate odor recognition, most studies only focus on  the analysis of antennal OBPs. According to the current research, the number of genes  encoding OBPs is highly variable among parasitiod species, and most studies have verified  that OBPs play an important role in host location of parasitoids by means of gene  silencing, fluorescence competitive binding assay, molecular docking and so on. Research on  host localization and olfactory mechanism of parasitoids has important ecological  significance, and also has a good application perspective in the integrated management of  agricultural insect pests. Applying volatile compounds, or growing companion plants and  transgenic plants that emit useful volatiles can enhance the host location of parasitoids  in the field, so as to achieve a better biological control efficacy against insect pests.

 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. 

【Aim】 The South American tomato pinworm, Tuta absoluta, is a newly invaded  devastating pest in China, causing severe damage to tomatoes. However, the current status  of insecticide resistance in newly invaded T. absoluta populations in China has not been  reported. The objective of this study is to clarify the susceptibility of the field  populations of T. absoluta from Xinjiang and Yunnan to six commonly used insecticides and  its relationship with the activities of detoxification enzymes. 【Methods】 Laboratory  toxicities of six frequently used pesticides to the 2nd instar larvae of Xinjiang and  Yunnan populations of T. absoluta were tested by using leaf-dip method. The synergistic  effects of three synergistic agents including the  CYP450 inhibitor piperonyl butoxide  (PBO), the esterase inhibitor triphenyl phosphate (TPP) and the GST inhibitor diethyl  maleate (DEM) on chlorantraniliprole were determined in the bioassay against the 2nd instar  larvae of T. absoluta, and the activities of detoxification enzymes including cytochrome  P450-dependent monooxygenase (CYP450), glutathione S-transferase (GST) and  carboxylesterase (CarE) in the 2nd instar larvae of the laboratory susceptible population  and resistant field population (Xinjiang population) of T. absoluta were determined by  enzyme activity assay, to ascertain the relationship of insecticide resistance with  detoxification enzyme activities. 【Results】 The susceptibility of Yunnan population of T.  absoluta to the six insecticides from high to low was emamectin benzoate, chlorfenapyr,  spinosad, indoxacarb, chlorantraniliprole, and beta-cypermethrin, while that of Xinjiang  population to the six insecticides from high to low was emamectin benzoate, chlorfenapyr,  chlorantraniliprole, spinosad, indoxacarb, and beta-cypermethrin. Compared with the  laboratory susceptible population, both Yunnan and Xinjiang populations showed the highest  level of resistance to chlorantraniliprole, with the resistance ratios of 212.7 and 169.3,  respectively. The bioassay results revealed that the three synergistic agents PBO, TPP and  DEM showed no obvious synergistic effect on chlorantraniliprole. The enzyme activity assays  showed that the activities of CYP450, GST and CarE in the 2nd instar larvae between the  laboratory susceptible population and resistant field population of T. absoluta were not 
significantly different. 【Conclusion】 Both Xinjiang and Yunnan populations of T. absoluta  show different levels of resistance to the tested six pesticides, with the highest  resistance level to chlorantraniliprole, and the insecticide resistance of T. absoluta is  unrelated to the activities of detoxification enzymes. The results of this study provide  valuable information for the field control and insecticide resistance management of T.  absoluta.

【Aim】Juvenile hormone (JH) and ecdysone (Ecd) play important roles in the growth and development of insects. The aim of this study is to clarify the regulatory mechanism of these two hormones and their metabolism-related genes on the development of Calliptamus italicus eggs.【Methods】The changes in contents of JH and Ecd during the development of C. italicus eggs were detected by ELISA assay, and the expression patterns of important genes (JHE, JHEH, DIB and EcR) in the metabolic pathways of JH and Ecd during the development of C. italicus eggs were detected by qRT-PCR.【Results】The JH content in C. italicus eggs was significantly higher at the diapause stage (stages Ⅳ-Ⅵ) than at the early developmental stage (stages Ⅰ-Ⅲ), and decreased significantly at the post-diapause developmental stage (stages Ⅶ-Ⅸ). The Ecd content in C. italicus eggs increased significantly at the early diapause stage (stage Ⅳ), then decreased significantly, and increased again at the post-diapause developmental stage. The expression level of JHE in C. italicus eggs increased firstly and then decreased at the early developmental stage and the post-diapause developmental stage, and was low at the diapause stage. The expression level of JHEH in C. italicus eggs also increased first and then decreased at the early developmental stage, and didn’t change significantly at the diapause stage, but increased significantly at the post-diapause developmental stage. The expression level of DIB in C. italicus eggs was higher at the diapause stage than at the early developmental stage and decreased at the post-diapause developmental stage. The expression level of EcR in C. italicus eggs did not change significantly at the early developmental stage and diapause stage, but increased gradually at the post-diapause developmental stage. 【Conclusion】The development of C. italicus eggs is co-regulated by JH and Ecd. JH is the important hormone to regulate diapause entry, while Ecd is the important hormone for diapause termination of C. italicus eggs. JH catabolic pathway of C. italicus eggs is mainly regulated by JHE before diapause termination and by JHEH after diapause termination. DIB and EcR can affect the development of C. italicus eggs by regulating Ecd content. These results lay a foundation for further revealing the diapause mechanism of C. italicus eggs.  

【Aim】 This study aims to elucidate the molecular characters of chitin synthase  (CHS) gene in Apis mellifera and uncover the function of CHS in immune response of A.  mellifera worker larvae to Ascosphaera apis stress. 【Methods】 The molecular characters,
conserved motifs and structural domains of the A. mellifera CHS protein were predicted and  analyzed using relevant bioinformatics software. Phylogenetic analysis of amino acid  sequences of CHS proteins in A. mellifera and other insects was performed with MEGA X  software. The dsRNAs of CHS and egfp were synthesized via in vitro transcription method,  and fed to the A. apis-stressed 3-day-old larvae of A. mellifera workers to perform  RNAi. RT-qPCR was used to determine the expression levels of CHS and immune-related genes  abaecin, apidaecin, birc5, defensin-1 and PGRP-S2 in the 5-day-old larval gut of A.  mellifera workers in response to A. apis stress. 【Results】 The CHS protein of A.  mellifera contains 1 572 amino acids belonging to 20 types of amino acids, among which the  numbers of amino acids with positive and negative charge are 177 and 169, respectively. CHS  has the molecular weight of 178.77 kD, isoelectric point of 6.65 and cellulose synthase  CESA3 catalytic structural domain. Three motifs (Motif 1, Motif 2 and Motif 3) and two  structural domains (Chitin_synth_2 and Glyco_trans_2_3) were identified in CHSs in 13  insect species such as A. mellifera and A. cerana. Phylogenetic tree showed that the CHSs  in A. mellifera and A. cerana of Hymenoptera showed the highest amino acid sequence  identities, and clustered into one branch with the bootstrap value of 100. The expression  level of CHS in the 5-day-old larval gut of A. mellifera in the dsCHS-fed group was  significantly down-regulated as compared to that in the dsegfp-fed control group, with  the interference efficiency of 29.40%. In the dsCHS-fed group, the expression levels of  abaecin, birc5 and defensin-1 in the 5-day-old larval gut of A. mellifera were extremely  significantly up-regulated, that of PGRP-S2 was significantly up-regulated, while that  of apidaecin was extremely significantly down-regulated, as compared with those in the d segfp-fed control groups. 【Conclusion】 A. mellifera CHS may be an intracellular  hydrophilic transmembrane protein. The amino acid sequences of CHSs in A. mellifera and  other insects are highly conservative, and those in A. mellifera and A. cerana are the most  highly conservative. CHS affects A. mellifera worker larval immune response to A. apis  stress.

【Aim】 The genetic differentiation research is an important link to understand the morphological diversity and adaptive evolution of honey bees. It is a prerequisite for the determination of the bioresource management unit and the protection unit and helps to protect the genetic resources of honey bees. This study aims to study the genetic differentiation and genetic resource distribution of the Asian honey bee, Apis cerana across the geographical environment in China by analyzing morphological differentiation. 【Methods】 A total of 6 147 worker bees of A. cerana were collected from 102 sampling sites across the complete distribution area of A. cerana in China. Sixty worker bees of each sampling site from 10-20 colonies were dissected and 33 morphological characteristics associated with the wings, individual size, hind leg, and body color were measured. A multivariate morphometric analysis was conducted and clusters with their morphological traits and distribution patterns were identified. 【Results】 According to the cluster results of discriminant analysis and principal component analysis, A. cerana in China can be divided into 14 morphological clusters. Five clusters with smaller body size were identified. Hainan cluster had the smallest body size, followed by South Yunnan cluster, Taiwan cluster, Southern cluster, and Northern cluster. These five clusters were significantly different in proboscis length, forewing length, the structure of the 3rd submarginal cell in the forewing, body color, and the length of the wax plate. Changbai cluster had the largest cubital index, wax plate size, and width of the stripe of tomentum on tergite 5. However, Bomi cluster of Tibet had the smallest width of the stripe of tomentum on tergite 5 in China. Northwest cluster had the longest hind legs. Five clusters in the West Sichuan Plateau were characterized by larger individuals and black body color. Batang cluster had the smallest cubital index (3.0169) and the largest individual size in China. The cubital index of the Aba cluster was inferior only to that of the Changbai cluster, and the wing lengths and the sizes of sternite 7 were the largest. Derong cluster was the darkest. Yajiang cluster was unique in wing vein angles (A4, N23, E9 and J10 were the smallest and B4 the largest). Chuandian cluster had the smallest body size on the Western Sichuan Plateau. 【Conclusion】 In this study, the morphometric analysis of A.  cerana was conducted based on collection of samples across the complete distribution area of A. cerana in China, especially those from Bomi of Tibet, Taiwan Province, and the Western Sichuan Plateau. Fourteen clusters of A. cerana were obtained in China, including Hainan cluster, southern Yunnan cluster, Changbai cluster, Taiwan cluster, Bomi cluster, Aba cluster, Batang cluster, Derong cluster, Yajiang cluster, Chuandian cluster, Chuangui cluster, Northwest cluster, Southern cluster, and Northern cluster. The results of this study provide a theoretical basis for the protection and exploitation of genetic resources of A. cerana in China.

 【Aim】 Adoxophyes orana is an important insect pest endangering apple, peach,  pear, jujube and other fruit trees. In recent years, the occurrence area of A. orana in the  apple and jujube orchards of Shaanxi has increased by years, causing increasing harm to  fruit production. The objective of this study is to clarify the roles of host-plant  volatiles in the olfactory communication of A. orana adults, so as to provide basic data  for the development of botanical attractants for A. orana. 【Methods】 The  electroantennogram (EAG) responses of the 2-day-old unmatched female and male adults of  A. orana to 51 host-plant volatile compounds were determined using EAG apparatus, and the  behavioral responses of A. orana adults to 15 volatile compounds with strong EAG amplitude  were measured with the device developed by our laboratory for testing the olfactory  behavior of tiny moths. 【Results】 The EAG test results showed that there were significant  differences in the relative EAG response values of A. orana adults to the tested 51  hostplant volatile compounds. Both sexes showed strong EAG responses towards  cis-3-hexen-1-ol, trans-2-hexen-1-ol, 1-hexanol, 1-heptanol, hexanal, (E) -2-hexenal, heptanal, octanal, nonanal, butyl acetate, isopentyl acetate and  cis-3-hexenyl acetate. In addition, male adults also displayed strong EAG responses to 3 -methyl-1-butanol, 1-penten-3-ol, benzaldehyde, butyl butyrate, ethyl acetate, ethyl  trimethylcrotonate, ethyl hexanoate, butyl propionate, cis-3-hexenyl isovalerate,  benzonitrile and lemonile. Obvious differences existed in the EAG response values towards  29 compounds of the tested 51 volatile compounds between the females and the males, and  female adults showed significantly higher EAG responses to (-)-α-phellandrene and  camphene than males, while male adults exhibited significantly higher EAG responses to the  other 27 volatile compounds than females. When the doses of volatile compounds ranged from  0.02 μg to 20 μg, the relative EAG response values did not increase significantly,  however, when the doses of volatile compounds increased from 20 μg to 200 μg, the  relative EAG values in both female and male adults significantly increased. The olfactory  behavioral tests revealed that the female adults showed obvious preference to hexanal,  heptanal, octanal and cis-3-hexenyl acetate, with the selection rates to them all  exceeding 58%, while the males showed obvious preferences to 1-hexanol, heptanal,  isopentyl acetate and benzonitrile. 【Conclusion】 The unmated male adults of A. orana show  higher sensitivities towards host-plant volatiles in the EAG responses than the unmated  females. 1-Hexanol, hexanal, heptanal, octanal, cis-3-hexenyl acetate, isopentyl acetate  and benzonitrile have obvious attractancy to female or male adults of A. orana and can be  applied in developing botanical attractants for this pest.

 The red imported fire ant, Solenopsis invicta, is a primary invasive pest in China. Currently, scientific researches, control strategies and policy regulations regarding S. invicta mainly focus on the filed of agriculture in China. Although S. invicta is also widely distributed in forests, grasslands, wetlands and urban green spaces and has caused huge damage, the occurrence characteristics and control strategies of S. invicta in these areas are largely overlooked. The occurence of S. invicta is closely associated with human disturbances such as felling, burning and soil turning, and natural factors such as biodiversity, forest canopy density and soil bareness. Due to the low levels of biological diversity and forest canopy density and high levels of human disturbances, there is a high risk of S. invicta invasion in plantation forests and adjacent areas. In natural forests, S. invicta is usually distributed in forest edges and windows, as well as burned areas where the sunlight can directly irradiate. Moreover, nurseries and urban green spaces have a high risk of S. invicta invasion because of large areas of bare soil and high levels of human activities. In areas with high levels of human activities, including plantation forests, nurseries and urban green spaces, S. invicta mainly threatens human health and infrastructure, and directly or indirectly damages trees. In addition, the invasion of S. invicta significantly decreases the abundance and diversity of arthropods in habitats and poses significant threats to wildlife in natural reserves and wetlands. Although it has been reported that S. invicta contributes to promoting seed migration and enhancing soil nutrient circulation under certain conditions, its harmful impacts far exceed its potential beneficial effects. Quarantine, monitoring and control are three important aspects to prevent S. invicta invasion in forestry. Wood, seedlings with soil, and turf are the main objects that may carry S. invicta and need to be quarantined, and fumigation can effectively eliminate S. invicta. Baiting and trapping are the main methods to monitor S. invicta. Recently, some new technologies, including remote sensing and radar technology, also have been developed to monitor S. invicta in grasslands and urban green spaces. Although chemical control is the most predominant control strategy for S. invicta, the use of highly toxic, broad spectrum and hardly degradable insecticides may negatively affect non-target organisms in natural reserves and wetlands. Therefore, it is essential to develop environmentally friendly agents and methods to control S. invicta.

【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.

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.

The collective set of odors received by insects is called as insect odorscape. Insects rely on the reception and discrimination of the odorscape to complete life activities, such as the object localization, feeding, mating and oviposition. The behavior of insects can be manipulated by odorscape management for pest control strategy. In this article, we reviewed the research progress in the composition and diffusion of insect odorscape, influences of odorscape on insect behavior, factors affecting odorscape, odorscape reception and discrimination of insects, and the application of odorscape management in pest control. Finally, we analyzed and prospected the development direction and research focus of insect odorscape management in the future. For insects, the odor released by target is dispersed into plumes by air flow and mixed with the background odor carried in the air, which together form the odorscape. Insects search and locate the target along the target odor. The behavior of insects can be affected by the shape, composition and concentration of target odors. The background odor plays a complementary or warning role during the target localization of insects. Different background odors can synergize or interfere with the target localization of insects. The insect odorscape is mainly affected by the temperature, humidity, light, heavy metal elements and plant diseases and insect pests in the environment. Studies showed that the olfactory receptors of insects capture odorscape and transmit those odor signals to olfactory nerve centers such as antennal sensilla lobe along the olfactory nerves. Then, the odorscape is analyzed in the nerve centers by the mode of elemental processing or configural processing. The influences of background odor on insect target localization may be the results of the reciprocal addition, competitive binding or signal crosstalk of different odor molecules during the olfactory sensing and coding. At present, several kinds of green pest control technologies have been developed based on the odorscape management, such as insect behavior regulators, exogenous elicitors, breeding the crop varieties that can release resistant volatiles, “push-pull” technology and plant-mediated support system for natural enemies. In the future, it is necessary to further explore the behavioral, electrophysiological and neurological mechanisms of odorscape discrimination in insects, and optimize and integrate the green control technologies related to odorscape management, so as to build rational and efficient odorscape for insect pest control.

【Aim】To evaluate the toxicity and ecological risks of the formulations of seven neonicotinoid insecticides to the 7-spot ladybird, Coccinella septempunctata, so as to provide a reference for scientific use of neonicotinoid insecticides and protection of C. septempunctata.【Methods】The acute toxicity of the formulations of seven neonicotinoid insecticides, including 10% imidacloprid WP, 40% acetamiprid SP, 50% dinotefuran WP, 50% clothianidin WG, 40% imidaclothiz WG, 17% flupyradifurone SL and 25% thiamethoxam WG to the 2nd instar larvae of C. septempunctata was determined by using the method of residual film in glass tube, and the ecological risks of these insecticides were assessed. The solutions of the seven insecticides were prepared according to the maximum recommended field application rate, and sprayed on potted plants in the greenhouse to investigate the larval survival rate of C. septempunctata.【Results】The results of the indoor experiments showed that the acute toxicity of the seven neonicotinoid insecticides to the 2nd instar larvae of C. septempunctata was ranked in a descending order: 40% acetamiprid SP>40% imidaclothiz WG>10% imidacloprid WP>50% dinotefuran WP>50% clothianidin WG>25% thiamethoxam WG>17% flupyradifurone SL. The pot experiment in the greenhouse showed that the larval survival rates of C. septempunctata at 7 d after treatment with the seven insecticides at the maximum recommended field application rate were 10.00%-77.50%, and the highest larval survival rate of C. septempunctata was tested in the treatment with 25% thiamethoxam WG, while the lowest survival rate was observed in the treatment with 40% imidaclothiz WG. The results of ecological risk assessment showed that for a single application, the risk of 40% acetamiprid SP was unacceptable with the hazard quotient value in the farm (HQ_in) of more than 5, and those of the other pesticides were acceptable with the HQ_in values of less than 5. The hazard quotient values for crop or vegetable field outside the farm (HQ_{off crop or vegetable}) and for fruit tree garden outside the farm (HQ_{off fruit tree}) of these insecticides to C. septempunctata were less than 5, indicating that the risk is acceptable. After the second spray after 7 d, the risks of 40% acetamiprid SP and 50% dinotefuran WP were unacceptable with the HQ_in values of more than 5, and those of the other insecticides were acceptable with the HQ_in values of less than 5. The HQ_{off crop or vegetable} and HQ_{off fruit tree} values of the other insecticides except 40% acetamiprid SP were less than 5, indicating that the risks of these insecticides are acceptable.【Conclusion】Acetamiprid and dinotefuran should not be used twice continuously and be used in rotation in order to avoid harm to C. septempunctata.

【Aim】 This study aims to clarify the expression pattern of odorant binding protein 1 (OBP1) in Aethina tumida and analyze the role of AtOBP1 in olfactory recognition of A. tumida.【Methods】 The cDNA full-length sequence of AtOBP1 was cloned based on the transcriptome and genome database of A. tumida and analyzed by bioinformatics. RT-qPCR was used to detect the expression levels of AtOBP1 in different developmental stages (egg, larva, pupa, female adult and male adult), different tissues (head, cuticle, wing, leg, fat body, gut, Malpighian tubules, testis and ovary) of the 7-day-old adult and in the head of different day-old adults of A. tumida after eclosion. The biological function of AtOBP1 in olfactory recognition of A. tumida was studied by RNA interference (RNAi) and Y-tube behavior choice experiment. 【Results】The cDNA full-length sequence of AtOBP1 gene (GenBank accession no.: MT211982.1) has six exons and an open reading frame (ORF) of 447 bp in length. AtOBP1 encodes 148 amino acid residues with PBP_GOBP superfamily conserved domain, and the predicted molecular mass and isoelectric point are 15.9 kD and 4.73, respectively. AtOBP1 protein is a dimer composed of six α-helics with six conserved cysteines that form three disulfide bonds. The phylogenetic tree also showed that AtOBP1 was closely clustered into one branch with TmOBP8 from Tenebrio molitor of Coleoptera. The RT-qPCR results showed that AtOBP1 was highly expressed in the pupal stage and the male adult stage, and was highly specifically expressed in the head and testis of adults. In addition, the expression level of AtOBP1 in adult head increased gradually with the day-old age, reached two peaks in the 5- and 7-day-old adult stages, respectively, and decreased in the 8-day-old adult stage. RNAi in combination with Y-tube behavior choice experiment results revealed that silencing of AtOBP1 resulted in significantly reduced preference of A. tumida adults to the pollen volatile compounds ethyl palmitate and ethyl linolenate.【Conclusion】AtOBP1 belongs to Classical OBPs family. AtOBP1 is mainly expressed in the head and testis of A. tumida adults, and may participate in the recognition process of the pollen volatile compounds ethyl palmitate and ethyl linolenate in A. tumida.
Key words: Aethina tumida; odorant binding protein; AtOBP1; RNAi; olfactory behavior

【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.

Hematophagous insects are arthropods that can spread insect-borne pathogens, including mosquitoes, sandflies, midges, kissing bugs, fleas and so on. Blood-feeding behavior makes them become the vectors transmitting malaria, dengue fever, filariasis, trypanosomiasis, and other acute infectious diseases. The fast and wide-spreading of vector-borne diseases, in addition to heavy damage to human health, might result in huge economic losses. Due to the scarcity of effective medicines and increasing drug resistance of pathogens, the interruption of reproduction of hematophagous insects is an effective measure to control the spread of insect-borne diseases. Juvenile hormone (JH) and 20-hydroxyecdysone (20E) play important roles in insect reproduction. JH binds to intracellular receptor complex Met/Tai to regulate the expression of JH/Met target genes, and then promotes vitellogenesis, which provides pre-requisite to bloodfeeding and oviposition of insects. Heterodimer EcR/USP is an intracellular receptor of 20E. The combination of 20E with EcR/USP complex can activate downstream gene expression and induce the synthesis of vitellogenin (Vg) to provide nutrition for the developing ovary. Nutrient signaling pathways (insulin signaling pathway and amino acidmediated target of rapamycin signaling pathway) can also activate Vg synthesis and promote insect reproduction. In addition, nutrient signaling pathways can interplay with JH and 20E signaling cascades to regulate the development and reproduction of hematophagous insects. Energy metabolism, such as carbohydrate and lipid metabolism, is the main energy source during insect reproduction, which can meet the extremely high energy requirements in different stages of reproductive development of hematophagous insects. Studies have shown that JH and 20E signaling pathways play important regulatory roles in energy metabolism. MicroRNAs have been proved to be closely related to physiological processes such as gut microbiome homeostasis, blood digestion and lipid metabolism in mosquitoes, further affecting the development mosquitoes. In recent years, with the innovation of molecular biology and sequencing technology, new progress has been made in the study of reproductive regulation mechanisms in hematophagous insects. In this article, we present the research progress and insights into molecular mechanisms of reproductive regulation in hematophagous insects, which will provide important clues for blocking the transmission of vector-borne diseases by regulating the reproduction of hematophagous insects.

True fruit flies are important insect pests attacking fruits and vegetables. The total damage caused by them worldwide is estimated to amount to be more than 2 billion US dollars annually. The oriental fruit fly, Bactrocera dorsalis, is one of the representatives of this kind of pests, causing serious losses to China’s citrus industry every year. The techniques based on male attractant and protein bait have been used in environment friendly strategies for pest monitoring and control. However, the performances of those baits in the field are unsatisfied and need to be further improved. With the reduction of the cost of high-throughput sequencing technology and the development of modern molecular biology technology, scientists proposed to discover the key molecular targets for olfaction by resolving the molecular mechanism of pest chemosensory first and develop more stable and efficient attractants with the identified new targets. In order to promote the development of behavioral regulation technology targeting key chemosensory molecules in B. dorsalis, we reviewed the research status of important chemicals regulating the behavior of B. dorsalis and the mechanism of chemosensory perception in this article. The important volatiles regulating the behavior of B. dorsalis include sex pheromones, plant volatiles and food-derived protein odors. Among them, the specific compounds identified by the first two have a clear relationship with the behavior of B. dorsalis adults. For example, pyrazine substances obtained from sex pheromones can attract females, methyl eugenol in plant volatiles can attract males, γ-octalactone can induce females to lay eggs; while the composition of food-derived protein odor is complex, although it has a certain efficacy in the field, there is a lack of function validation of specific compounds in female and male insect behavior. In the olfactory sensory mechanism, there is only a morphological description of the peripheral nerve sensilla and the central antennal lobe, and the function of different types of olfactory neurons is not clear. A large number of chemical sensory proteins have been identified in B. dorsalis, including 49 odorant binding proteins (OBPs), 60 odorant receptors (ORs), 23 ionotropic receptors (IRs) and 17 gustatory receptors (GRs), through bioinformatics analysis at present. However, the number of olfactory genes functionally analyzed is small. In conclusion, although some compounds with behavioral activity on B. dorsalis have been identified, and a large number of olfactory proteins have been used as candidate molecular targets, the corresponding relationship between “chemical substances-olfactory molecular targets and nerve-behavior” is lacking, which greatly limits the role of olfactory molecular targets in attractant development. Therefore, on this basis, we put forward a development strategy for the behavioral regulation technology of B. dorsalis based on olfactory key molecular targets, to provide new ideas for the design and screening of effective behavioral regulators of B. dorsalis.

【Aim】 Trichogramma dendrolimi is an important egg parasitoid applied in the biological control of lepidopteran pests. This study aims to investigate the effects of oviposition intensity on the titer of Wolbachia in parthenogenetic T. dendrolimi and its parthenogenetic reproductive phenotype induced by Wolbachia. 【Methods】 The effects of different oviposition intensities of females of T. dendrolimi in three treatment groups (supplied with host eggs for only 1 h per day, supplied with host eggs for 24 h every other day and supplied with host eggs all the time) on its biological parameters including the daily proportion of offspring males, daily fecundity, cumulative proportion of offspring males, and cumulative fecundity within 7 d were investigated in the laboratory. Besides, the Wolbachia titers (the copy numbers of wsp) in T. dendrolimi females without oviposition experience (the control), supplied with host eggs for only 1 h per day and supplied with host eggs all the time were detected by fluorescence quantitative real-time PCR. 【Results】 The cumulative proportion of offspring males of T. dendrolimi females supplied with host eggs all the time was significantly higher than that of females supplied with host eggs for only 1 h per day, but was not significantly different from that of females supplied with host eggs for 24 h every other day. The daily proportions of offspring males in the three treatment groups significantly increased with wasp age, and the increase rate was the highest in the treatment group of females supplied with host eggs all the time. The cumulative fecundity of T. dendrolimi females supplied with host eggs all the time was significantly higher than those of females supplied with host eggs for only 1 h per day and females supplied with host eggs for 24 h every other day. The daily fecundity in the three treatment groups significantly decreased with wasp age, but the decrease rate was the highest in the treatment group of females supplied with host eggs all the time. The Wolbachia titer in T. dendrolimi females without oviposition experience was significantly higher than that in T. dendrolimi females supplied with host eggs all the time, but showed no significant difference from that in T. dendrolimi females supplied with host eggs for only 1 h per day. 【Conclusion】 The results suggest that both Wolbachia titer and parthenogenetic phenotype of T. dendrolimi decline when its females can deposit their eggs without limitation. Limiting time for oviposition will be helpful to maintain Wolbachia titer and parthenogenetic phenotype. The results provide references for understanding the interaction between Wolbachia and host Trichogramma and the application of thelytokous parthenogenetic T. dendrolimi for controlling pest insects.

 【Aim】 The phytophagous piercing-sucking insect saliva protein participates in the regulation of plant defense response against insects and affects insect adaptability to host plants. The aim of the present study is to clone the important salivary protein gene Nl15 in the brown planthopper, Nilaparvata lugens, and to investigate its temporal and spatial expression patterns, so as to clarify its roles in virulence o f N. lugens. 【Methods】 Based on the transcriptome data of IR56 population of N. lugens, the cDNA sequence of Nl15 was cloned from N. lugens by RT-PCR, and subjected to bioinformatics analysis. The expression profiles of Nl15 in different developmental stages (egg, 1st-5th instar nymph, and female and male adult) and female adult tissues (head, thorax, abdomen and leg) of TN1 and IR56 populations of N. lugens were determined by qPCR. The RNAi of Nl15 was carried out by dsRNA microinjection into the 4th instar nymphs of TN1 and IR56 populations of N. lugens. The relative expression levels of Nl15 in N. lugens nymphs after RNAi of Nl15 and defense-related genes OsLecRK4, OsMPK10, OsWRKY24, OsLox, OsNPR1, and OsGns5 in rice plants fed by N. lugens nymphs for 3 d following RNAi of Nl15 were detected by qPCR. The survival rate and the honeydew amount and body weight gain of N. lugens adults after RNAi of Nl15 were determined by bioassay. 【Results】 The cDNA sequence of Nl15 (GenBank accession no.: OK181113) of N. lugens was cloned. It has an open reading frame of 1 008 bp in length, encoding 335 amino acids with the predicted isoelectric point of 7.54 and the molecular weight of 38.7 kD. The Nl15 protein contains a signal peptide sequence of 23 aa and a predicted glycosylation modification site, whereas has no transmembrane domain and other known functional domains. Nl15 shares 45% amino acid sequence identity with the homologous protein from Laodelphax striatellus. Developmental expression profile revealed that Nl15 was expressed in various developmental stages of N. lugens, with the highest expression level in the 3rd-4th instar nymphs. Tissue expression profile showed that Nl15 exhibited the highest expression level in the head of female adults of N. lugens, with a higher expression level in the head of IR56 population than in the head of TN1 population. RNAi results showed that the expression level of Nl15 in ds Nl15 injection group was significantly down-regulated by 89.5%, the survival rate and the honeydew amount and body weight gain of adults of N. lugens were significantly decreased, and the expression levels of the above six rice defense-related genes were significantly up-regulated as compared to those in the control group (ds GFP injection group). 【Conclusion】 Nl15 in IR56 population of N. lugens is involved in the interaction of defense and counter defense between N. lugens and rice. This study provides insights into the mechanisms by which N. lugens overcomes resistance genes and the molecular network of interactions between insects and plants.

 【Aim】The aim of this study is to find out the reference genes stably expressed in different developmental stages and adult tissues of Grapolita molesta and in its adults after treatment with different concentrations of three insecticides, so as to lay a foundation for the subsequent study on target gene expression in G. molesta.【Methods】Ten candidate reference genes (β-actin, 18S rRNA, β-tubulin, EF-1α, RPL13, RPL32, RSPL40, UBC7, α-tubulin and RPS20) were selected based on G. molesta transcriptome data. The expression levels of the candidate reference genes in different developmental stages (egg, 1st-5th instar larvae, pupa and adult) and different adult tissues (head, foregut, midgut, hindgut, fat body, Malpighian tubules, testis and ovary) of G. molesta and in G. molesta adults treated with three insecticides at different concentrations (avermectin: 19.819, 72.897 and 179.663 μg/mL; imidacloprid: 17.638, 163.323 and 762.986 μg/mL; and lambda-cyhalothrin: 33.791, 96.123 and 198.282 μg/mL) with the method of residual film in glass tube were detected using real-time quantitative PCR (qRT-PCR). The expression stabilities of the 10 candidate reference genes were evaluated by geNorm, NormFinder, ΔCt, BestKeeper and RefFinder. The cytochrome P450 gene CYP354A32 of G. molesta was selected for validation. 【Results】 qRT-PCR results combined with software evaluation results revealed that the expression stabilities of the reference genes in different developmental stages of G. molesta were ranked in a descending order of β-tubulin, 18S rRNA, EF-1α, RPL13, β-actin, RPS20, UBC7, RPL32, α-tubulin and RSPL40, those in different adult tissues were ranked in a descending order of UBC7, β-tubulin, β-actin, 18S rRNA, RSPL40, EF-1α, RPS20, RPL13, RPL32 and α-tubulin, and those in adults after exposure to different concentrations of avermectin, imidacloprid and lambda-cyhalothrin were ranked in a descending order of RPS20, RPL13, β-tubulin, β-actin, RPL32, RSPL40, EF-1α, UBC7, α-tubulin and 18S rRNA. The expression characteristics of CYP354A2 analyzed by using the obtained reference gene combinations showed that CYP354A2 was highly expressed in the old larvae and adults when using the combination of β-tubulin, EF-1α and 18S rRNA as the reference genes, and was highly expressed in the testis and ovary of adults when using the combination of UBC7, β-tubulin and β-actin as the reference genes. After G. molesta adults were exposed to different concentrations of insecticides, only the expression level of CYP354A2 in the treatment with 19.819 μg/mL avermectin was higher than that in the control, while the expression levels of CYP354A2 in treatments with other concentrations of insecticides were lower than that in the control when using the combination of RPS20, RPLB and β-tubulin as the refernece genes.【Conclusion】 The combination of β-tubulin, 18S rRNA and EF-1α is recommended as the reference genes for studying the target gene expression in different developmental stages of G. molesta, that of UBC7, β-tubulin and β-actin as the reference genes for studying the target gene expression in different adult tissues of G. molesta and that of RPS20, RPL13 and β-tubulin as the reference genes for studying the target gene expression in adults of G. molesta after treatment with different concentrations of avermectin, imidacloprid and lambda-cyhalothrin.

【Aim】To identify and analyze the genes and full-length transcripts of  serine/threonine protein kinases of Apis mellifera ligustica using previously gained  high-quality long-read nanopore sequencing data, and to provide reference information and  bases for further functional study.【Methods】Based on the previously obtained  high-quality long-read nanopore sequencing data of A. m. ligustica, the genes and  full-length transcripts of serine/threonine protein kinases were screened from the Nr  database by Blast. The screened full-length transcripts of serine/threonine protein kinases  were compared with the annotated transcripts in the reference genome of A. mellifera  (Amel_HAv3.1) using gffcompare software to identify the unannotated new genes and new  transcripts. The types of alternative splicing (AS) events occurring in serine/threonine  protein kinase genes were identified using Astalavista software. Visualization of the  structure of spliceosomes was performed with IGV browser. RT-PCR was employed to confirm  the authenticity of randomly selected six AS events.【Results】In total, 71 genes and 335  full-length transcripts of serine/threonine protein kinases of A. m. ligustica were  identified, and one new gene and 97 new transcripts were discovered. The structure of 14  annotated genes was optimized, and the 5′ends of six genes and the 3′ends of eight genes  were prolonged, respectively. A total of 57 AS events were identified in seven genes of  serine/threonine protein kinases in A. m. ligustica, including 40 exon skipping (ES) events,  15 alternative 5′splicing site (A5SS) events and two alternative 3′splicing site (A3SS)  events. RT-PCR results of randomly selected six AS events indicated that all of the target  fragments were in accordance with the expected sizes, confirming the authenticity of AS  events.【Conclusion】 Genes and full-length transcripts of serine/threonine protein kinases  of A. m. ligustica were systematically identified and the structure of the serine/threonine  protein kinase genes annotated in A. mellifera reference genome was optimized in this  study.

The tomato leafminer, Tuta absoluta, is native to South America and a quarantine pest in the world nowadays, which can reduce the yield of the main host crop tomato by 80%-100% in severe cases. In over a decade, this insect pest has invaded and spread from its origin to almost the entire continent of Asia, Africa and Europe, becoming a major threat to the world tomato industry. T. absoluta was discovered in Ili, Xinjiang in 2017 and spread to Yunnan, Gansu and other regions in a short time, greatly threatening the healthy development of the tomato industry and other related agricultural industries in China. Internationally, sex pheromone-based monitoring, mass trapping and mating disruption control have become one of the important  measures to control T. absoluta. In order to study the efficient and environmentally friendly population dynamics monitoring and control technology of T. absoluta, we summarized the research and application status of the sex pheromone in mornitoring, early warning and control of T. absoluta in this article. The females of T. absoluta release sex pheromones to attract males to mate mainly in the morning, and adult mating reaches the peak at 7:00 a.m. In 1995 and 1996, the major and minor components of the sex pheromone released from T. absoluta and their synthetic methods were reported successively. The major and minor components of this sex pheromone are (3E, 8Z, 11Z)-tetradecatrienyl acetate (TDTA) and (3E, 8Z)-tetradecadienyl acetate (TDDA), respectively, which constitute the sex pheromone in a ratio of about 90∶10. Bioassay results revealed that TDTA had a strong attraction to males, which could be further enhanced when its mixture with TDDA was used. In recent years, more efficient and convenient synthetic methods of sex pheromone components have been developed, providing good conditions for their large-scale production and application. At present, the sex pheromone of T. absoluta has been widely used in the control of this insect pest in the world, and good results have been achieved. Among the reported sex pheromone traps commonly used for monitoring and mass trapping this insect pest, the water basin trap and triangle trap are more effective. The common doses of sex pheromone contained in commercial lure core are 0.5, 0.8 and 3.0 mg. For field application, the corresponding trap type and sex pheromone dose should be selected according to the actual situation of habitat and growth stage of crops, damage degree, local natural conditions, etc. In addition, the mating disruption by using sex pheromone is also common in the control of T. absoluta, and its successful application requires a highly enclosed environment. Because sex pheromone has the advantages of high efficiency, safety and environmental protection in the monitoring and control of T. absoluta, its related research results can provide important reference for the sustainable control strategies and measures of this insect pest in China.

Thrips are important pests of agricultural and horticultural crops, causing  enormous economic losses by direct feeding and indirect transmission of the  plant-pathogenic virus. Plant secondary metabolites play a pivotal role in plant-insect  interactions. The manipulation of insect behavior using plant secondary metabolites to  protect crop plants from pest infestation is a promising eco-friendly control tactic. In  this article, plants, plant extracts, essential oils and chemical compounds that have  attractive, repellent, oviposition and feeding deterrent effects, fumigation toxicity and  toxic activities to thrips were reviewed, and the potential of plant secondary metabolites  for thrips management was discussed. Volatiles or essential oils from 54 plant species in  27 families, 29 benzenoids, 17 pyridines and 13 terpenes are attractive to thrips and could  be used as trap plants and attractants. Volatiles or essential oils from 40 plant species  in 17 families, 20 terpenes and 6 benzenoids show repellency against thrips and could be  used as repellent plants and repellents. Extracts or essential oils from 42 plant species  in 20 families, 6 alkaloids, 15 terpenes and 5 benzenoids have oviposition and feeding  deterrent effects, fumigation toxicity and toxic activities to thrips, and could be  developed into botanical pesticides and fumigants. Finally, current problems of plant  secondary metabolites in thrips management, such as unstable effects, lack of field  application technology and unclear muchamisms, were discussed, and potential research  directions were prospected, which are of great significance to thrips management based on  plant secondary metabolites.

【Aim】 This study aims to sequence and analyze the complete mitochondrial genome (mitogenome) of Aclerda takahashii, which represents the first complete mitogenome of the family Aclerdidae of Hemiptera, and to investigate the phylogenetic relationships with other Coccoidea groups. 【Methods】 The whole mitogenome of A. takahashii was sequenced based on the Illumina sequencing technique, and analyzed with bioinformatics methods. The phylogenetic trees of hemipteran insects were constructed based on the reported complete mitochondrial genomes of 31 speciec of 15 families of Hemiptera using the maximum likelihood (ML) and Bayesian inference (BI) methods. 【Results】 The mitogenome of A. takahashii is 16 599 bp in length with high A+T content (84.51%). The truncated tRNAs are common in this mitogenome, ten tRNAs lacking of a dihydrouridine (DHU) arm or TΨC (T) arm. The DHU and T arm of tRNAser(S1) and tRNAser(S2) are both missing. The phylogenic trees showed that Aclerdidae has the closest relationship with Coccidae. 【Conclusion】 This study reported the first mitogenome of Aclerdidae, and revealed that truncated tRNAs are prevalent in the mitogenome of A. takahashii, providing data for the further systematic research of mitogenomes of scale insects.

【Aim】To clarify the function of sulfakinin (SK) and sulfakinin receptor (SKR) in the feeding behavior of Nilaparvata lugens.【Methods】The full-length cDNA sequences of sulfakinin gene Nlsk and sulfakinin receptor gene Nlskr of N. lugens were cloned by PCR and subjected to bioinformatical analysis. The expression levels of Nlsk and Nlskr in different developmental stages (egg, 1st-5th instar nymphs, and male and female adults) and different tissues (head, antenna, wing, proboscis, leg, gut and Malpighian tubules) of the female adult of N. lugens were analyzed by qRT-PCR. The 3rd instar nymphs of N. lugens were injected with ds Nlskr for gene silencing and the expression level of Nlskr in the 4th instar nymph was detected by qRT-PCR. The food intake of the 4th instar nymph after the  Nlskr silencing was measured. GO and KEGG analyses of differentially expressed genes (DEGs) and qRT-PCR verification of feeding-related genes based on the previously constructed transcriptome database of the 4th instar nymphs after RNAi of Nlskr were performed. 【Results】 The full-length cDNA sequences of Nlsk (GenBank accession number: AB817281) and Nlskr (GenBank accession number: BAO01059.1) of N. lugens were cloned by PCR. Sequence alignment results showed that the NlSK mature peptide of N. lugens has a C-terminal FMRFamide polypeptide structure that is conserved with other species. NlSKR has a highly conserved transmembrane domain with homologous receptors of other insects. The results of qRT-PCR showed that Nlsk and Nlskr were highly expressed in the egg and 1st instar nymph, and mainly in the head. Nlskr was also highly expressed in the proboscis of N. lugens. Silencing Nlskr significantly increased the food intake of the 4th instar nymphs of N.  lugens. Based on transcriptome data, GO and KEGG analysis result of DEGs showed that silencing of Nlskr by RNAi significantly affected the expression of the olfactory, gustation, energy metabolism, and feeding-related neuropeptides and receptor genes. The qRT-PCR verification results of feeding-related genes showed that silencing Nlskr decreased the expression levels of Nl7tmOR, NlOAR-3R, NlUH-FAF and NlTRP-161A, and increased the expression levels of NlGr64f, NlUE-E2 and NlTHR.【Conclusion】 This study reveals that sulfakinin and its receptor are involved in regulating the feeding behavior of  N. lugens, providing a potential target for the development of pest insect feeding behavior inhibitors.

【Aim】 This study aims to establish the adult antennal transcriptome database of  Lytta caraganae, and explore and identify genes of olfactory-related odorant-binding  proteins (OBPs) and chemosensory proteins (CSPs) in its adult antennae. 【Methods】  Transcriptome analysis of adult antennae of L. caraganae was performed on Illumina HiSeq  platform. Assembled genes were annotated by alignment against public databases NR, NT, KO,  Pfam, Swiss-Prot, GO and KOG. OBP and CSP genes of L. caraganae were screened according to  the annotation results. Structural characteristics and evolutionary relationship of OBP and 
CSP genes were analyzed by ClustalX 1.83 and MEGA 7.0 software, respectively. The  expression levels of OBP and CSP genes in female and male adult antennae of of L. caraganae  were determined by qRTPCR. 【Results】 A total of 51 028 transcripts and 41 998 unigenes  were obtained from the adult antennal transcriptome of L. caraganae. Gene annotation  results showed that L. caraganae genes have the highest match (87.3%) to those of  Tribolium castaneum. Twenty-wo OBP genes and seven CSP genes were screened. Sequence  alignment result showed that 13 LcarOBPs are classified into classic OBPs， which contain  six conserved cysteine residues. Phylogenetic tree showed that LcarOBPs and LcarCSPs show  the highest amino acid sequence identity with OBPs and CSPs of Hycleus cichorii and H.  phaleratus, respectively, indicating the closest evolutionary relationship. qRT-PCR  results showed that two LcarOBP genes and two LcarCSP genes were highly expressed in the  male adult antennae of L. caraganae, while ten LcarOBP genes and two LcarCSP genes highly  expressed in the female adult antennae. 【Conclusion】 The OBP and CSP genes in adult  antennae of L. caraganae have been identified for the first time, providing a theoretical  basis for further study on the mechanism of olfactory recognition in L. caraganae.

【Aim】 In the previous studies it was found that the learning ability of Apis mellifera ligustica worker bees treated with imidacloprid is decreased, and transcriptomic analyses showed that the expression of major royal jelly protein 1 gene Mrjp1 is significantly down-regulated in the brains of bees treated with imidacloprid, suggesting that MRJP1 may be involved in olfactory learning in honeybees. This study aims to verify the crucial role of MRJP1 in olfactory learning in A. mellifera ligustica workers through silencing Mrjp1 by RNA interference (RNAi). 【Methods】 The cDNA sequence of Mrjp1 was obtained by cloning technique and validated by sequencing, and then the sequence was used for designing primers for generating dsRNA for knockdown of Mrjp1 by RNAi. The worker bees of A. mellifera ligustica injected with dsMrjp1 were assigned to the treatment group (dsMrjp1-injected group), and those injected with dsEGFP were assigned to the control group (dsEGFP-injected group). Then, the olfactory learning and memory abilities of the two groups were compared based on the proboscis extension response (PER) assay. Finally, the relative expression level of Mrjp1 in the brain of A. mellifera ligustica workers after injection of dsMrjp1 was detected by quantitative realtime PCR (qRT-PCR). 【Results】There was a significant difference in the learning ability of A. mellifera ligustica workers between the dsMrjp1injected group and the dsEGFP-injected group, with the learning ability of the dsMrjp1-injected group significantly decreased. However, there was no significant difference in the faculty of memory of A. mellifera ligustica workers at 2 h after learning between the two groups. The qRT-PCR results showed that the expression level of Mrjp1 in the brain of A. mellifera ligustica workers in the dsMrjp1-injected group was significantly lower than that in the dsEGFP-injected group, indicating that A. mellifera ligustica workers with decreased learning ability correspondingly exhibit lower expression level of Mrjp1. 【Conclusion】 After knockdown of Mrjp1 by RNAi, the olfactory learning performance of A. mellifera ligustica workers is significantly decreased, while their memory performance is not significantly affected, suggesting that Mrjp1 is probably one of the key genes regulating learning in A. mellifera ligustica. The results of this study contribute to further understanding of the molecular mechanism related to olfactory learning in honey bees.

【Aim】 The phototaxis of moths is directly related to the transformation of light and dark-adapted states of compound eyes. This study aims to clarify the relationship between light and transformation of light- and dark-adapted states of compound eyes of Spodoptera frugiperda. 【Methods】 Quickly taking photos at different time, the light- or dark-adapted state of compound eyes, light and dark-adapted transformation rate of S . frugiperda under light- or dark-adapted state and exposed to yellow light of different light intensities were statistically investigated. 【Results】 The maintenance rate of light-adapted state of compound eyes of S. frugiperda adults gradually increased as the light intensity increased after exposure to yellow light for 1 h under light-adapted state, those of males under yellow light at 0.1-0.5 and 4-6 lx were 67.77% (32.23% into dark-adapted and middle states) and 100%, respectively, while those of females under yellow light at 7-10 lx reached 98.90%. When S. frugiperda adults were exposed to yellow light for 3 h under light-adapted state, the maintenance rate of light-adapted state of compound eyes also gradually increased as the light intensity increased, those of males and females under yellow light at 0.1-0.5 lx were 50.00% and 32.23%, and those of females and males under yellow light at 7-10 lx were 90.00% and 100%, respectively. When S. frugiperda adults were exposed to yellow light at different intensities for 30 min under dark-adapted state, the compound eyes gradually transformed into light-adapted state, the light-adapted transformation rates of compound eyes of both females and males under yellow light at 0.1-0.5 lx were 93.33%, and those of females under yellow light at 0.6-0.9 lx and males under yellow light at 1-2 lx were 100%. 【Conclusion】 These results suggest that S. frugiperda adults have strong photosensitivity, and females are slightly more photosensitive than males.

【Aim】 The effects of chronic exposure to the sublethal concentration (LC₂₀) of dinotefuran on the growth and development of Sitobion avenae were studied in order to provide a theoretical basis for the scientific use of dinotefuran to control S. avenae and delaying the development of the resistance to the pesticide and extending the useful life of pesticide. 【Methods】 The LC₂₀ of dinotefuran to the 3rd instar nymphs of S. avenae was determined by using the leaf-dip method andusedforchronic exposure on S.
avenae for 15 generations. The resistance ratio of S. avenae to dinotefuran was determined, the developmental duration, reproduction and survival rates of S. avenae of two successive generations which were raised with wheat seedlings in test tube were recorded, and the body length, body width and body weight of adults of F₀ generation were measured. The differences in the body length, body width, body weight, survival rate, adult longevity and number of offspring produced between lowly resistant strain of various generations and the susceptible strain were analyzed by population specific life table and DPS software. 【Results】 After chronic exposure to LC₂₀ of dinotefuran for 15 generations, the resistance of S. avenae reached low level (6.54-fold). The developmental duration of the 2nd, 3rd and 4th instar nymph of F₀ generation of the lowly resistant strain was significantly longer than that of the susceptible strain, and the body length, body width and body weight of F₀ generation of adults of the lowly resistant strain were significantly increased, but the number of offspring produced per adult and adult longevity of F₀ generation of the lowly resistant strain were significantly reduced or shortened as compared to those of the susceptible strain. The adult survival rate, number of offspring produced per adult and adult longevity of F₁ generation of the lowly resistant strain were significantly reduced, the 2nd instar nymphal duration and nymphal duration of F₁ generation of the lowly resistant strain were significantly shortened as compared to those of the susceptible strain. The net reproductive rate (R₀), intrinsic rate of increase (R_m) and finite rate of increase (λ) of F₀ and F₁ generations of the lowly resistant strain were significantly lower than those of the susceptible strain, while the population doubling time (DT) of F₀ and F₁ generations and the mean generation time (T) of F₁ generation of the lowly resistant strain were significantly prolonged as compared to those of the susceptible strain. 【Conclusion】 Chronic exposure to LC₂₀ of dinotefuran results in the increase in the resistance of S. avenae to dinotefuran and individual size of adults of F₀ generation, while inhibits the longevity and fecundity of F₀ and F₁ generations of S. avenae.
Key words: