【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.

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.

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.

 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.

【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】To explore the effects of oviposition season and geographical latitude on  life history traits of the Japanese pine sawyer beetle, Monochamus alternatus, so as to  provide a basis for the accurate prediction and management of this insect pest.【Methods】 Six monitoring plots along the latitudinal gradient of about 1° in Jiangxi Province,  Southeast China were established, then the generation differentiation and developmental  duration were investigated by field pine tree trunk covering observation, and the  overwintering larval instars were surveyed through dead wood dissecting.【Results】The 2nd  generation differentiation of M. alternatus occurred in southern and central Jiangxi. The  proportion of the differentiation entering the 2nd generation decreased from 45.75% to 2. 46% in southern Jiangxi and from 17.42% to 0 in central Jiangxi with the delay of  oviposition season, while there was only one generation in northern Jiangxi, where no  generation differentiation occurred. The proportion of the eggs laid at the same month  entering the 2nd generation decreased from 21.92% to 0 with increasing geographical  latitude. The egg-pupal duration in differentiated and undifferentiated individuals in the  forest was 110.66-122.01 and 330.61-366.01 d, respectively, and showed a latitudinal  co-gradient variation and a counter-gradient variation, respectively. However, no  significant difference was found in the developmental duration of differentiated and  undifferentiated individuals. The overwintering larvae were at the 2nd-5th instars in  southern and central Jiangxi and 4th-5th instars in northern Jiangxi, and the proportion of  the 2nd instar overwintening larvae significantly decreased from 12.47% to 0 and the  proportion of the 5th instar overwintering larvae significantly increased from 45.33% to  98.40% with increasing geographical latitude.【Conclusion】Oviposition season and  geographical latitude have certain effects on the life history traits of M. alternatus,  showing that oviposition season and geographical latitude significantly affect the  generation differentiation proportion of this beetle, but not on the developmental duration  of differentiated individuals and undifferentiated individuals. The larval instars and  proportion of overwintering insects are obviously affected by geographical latitude.

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

【Aim】 To 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.

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 South American tomato pinworm, Tuta absoluta, is a worldwide devastating pest on tomatoes. This insect pest invaded China in 2017 and showed a trend of spread, posing a serious threat to tomato production in China. Unreasonable use of insecticides for control of this insect pest has led to the increasing level of resistance and the decrease of control efficacy. Consequently, there is an urgent need to develop novel green control technologies. Physical control trapping technique and olfactory behavior manipulation technique are important components of the integrated pest management program. In this article, the research progress of physical control trapping (light traps and color traps) and olfactory behavior manipulation (sex pheromone and plant volatiles) in T. absoluta were summarized. Color significantly affects the trapping efficiency of pheromone traps and sticky color traps. White, black and blue traps attract more T. absoluta adults in the field. The black light traps and LED traps with the wavelength of 470 nm have the best trapping efficiency on T. absoluta, and also have synergistic effects on sex pheromone. The sex pheromone of T. absoluta includes the major component (3E, 8Z, 11Z)-tetradecatrienyl acetate and the minor component (3E, 8Z)-tetradecadienyl acetate, in a ratio of ~9∶1. The optimal trapping blend for mass trapping is (3E, 8Z, 11Z)-tetradecatrienyl acetate and (3E, 8Z)-tetradecadienyl acetate in a ratio of 95∶5, and delta traps with sex pheromone lure show the highest trapping efficiency in comparison with other trap types. The sex pheromone of T. absoluta has been widely used for monitoring, mass trapping and mating disruption. Plant volatiles and traditional food attractant volatiles affect the host selection and oviposition of T. absoluta. Octyl acetate, phenylacetaldehyde+acetic acid blend, acetic acid+3-methyl-1-butanol blend, and a blend consisting of limonene, β-ocimene, α-terpinene, δ-elemene and (E)-β-caryophyllene show attractive activities to T. absoluta. p-Quinone, 2-carene, d-curcumene and 1,2-diethylbenzene in tomato can serve as oviposition stimulants to T. absoluta. By contrast, 1-fluorododecane, caryophyllene, curcumene, elemene, humulene, zingiberene, tridecan-2-one, undecan-2-one, (Z)-3-hexenyl propanoate and methyl salicylate have adverse effects on host selection, oviposition or growth and development of T. absoluta. Finally, current problems of behavioral manipulation techniques of T. absoluta, such as unclear mechanisms, unstable effects, and lack of combined application technology with other green control strategies, were discussed, and potential research directions were prospected, which will provide a reference for the development of green control technologies based on insect behavioral manipulation in this pest.

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.

【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】 Altitudinal gradient has an important impact on the distribution and maintenance of insect species. This study aims to provide a theoretical basis for studying the impact of altitudinal gradient on insect distribution by exploring the variation law and distribution characteristics of species diversity of rove beetles at different altitudinal gradients in the reserve.【Methods】From May 2020 to April 2021, three kinds of passive acquisition devices, flight interception trap, Malaise trap and pitfall trap, were used in Mangshan National Nature Reserve, Hunan Province, Central China to investigate the species of rove beetles at the altitudinal gradients of 500-800 m (Ⅰ), 800-1 100 m (Ⅱ), 1 100-1 400 m (Ⅲ) and 1 400-1 700 m (Ⅳ), and the species diversity, community structure similarity and species abundance of rove beetles at different altitudinal gradients were analyzed using Excel 2016 and past 3.【Results】From May 2020 to April 2021, we collected and recorded 2 135 rove beetles in Mangshan National Nature Reserve, Hunan Province, belonging to 9 subfamilies, 45 genera and 111 species, of which the number of species in Staphylininae was the most (25 genera and 63 species), and the numbers of species in Steninae and Oxytelinae were the least (both 1 genus and 1 species). The Shannon-Wiener diversity index, Mangalef richness index, Berger-Parker dominance index and Pielou’s evenness index of rove beetles were 3.8280, 2.3920, 0.1217 and 0.4140, respectively. There were differences in species diversity indexes of rove beetles at different altitudinal gradients. The species number, individual number, Shannon-Wiener diversity index and Margalef richness index of rove beetles at the altitudinal gradient Ⅲ were significantly higher than those at the altitudinal gradient Ⅰ. The species of rove beetles were poor and the dominant species were prominent at the altitudinal gradient Ⅰ, but the community structure was relatively stable. Altitudinal gradient Ⅱ was the transition gradient from low altitude to medium altitude. The species of rove beetles were rich, the community structure was complex, the dominant species were prominent and concentrated, and the community structure was relatively unstable at the altitudinal gradient Ⅲ. The species of rove beetles at the altitudinal gradient Ⅳ were relatively poor as compared with those at the altitudinal gradient Ⅲ. The similarity coefficient between the altitudinal gradient Ⅲ and altitudinal gradient Ⅳ was the highest, showing medium similarity, while those between other altitudinal gradients showed medium dissimilarity.【Conclusion】 The results of this study suggest that there are great differences in the distribution characteristics of rove beetles among different altitudinal gradients. Rove beetle species are poor and the community structure is single in low altitude areas. The medium altitude area is rich in rove beetle species, and has complex community structure and prominent dominant species. Compared with the medium altitude area, the high altitude area is relatively poor in rove beetle species. The similarity coefficient of rove beetle species between the medium-high altitude area and the high altitude area is the highest.

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】 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.

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.

 【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】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.

【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.  

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.

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.

 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.

 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.

 Unmovable cultural relics are important physical materials that reflect the development of social productivity and social life in the past. They are important research objects for cultural relics, with extremely high historical, artistic and scientific values. Unmovable cultural relics suffer from various deterioration effects for being outdoors. Biodeterioration caused by pests is one of the important reasons for cultural relics damage. Among unmovable cultural relics, ancient buildings, murals and earthen sites are particularly affected by insect pests. According to the classification of cultural relics, we expounded on the main types and mechanisms of insect pests in ancient buildings, murals and earthen sites, and summarized the current methods of pest control in these cultural relics in this article. Physical and chemical control methods are traditionally used to prevent and control pests in cultural relics. The chemical methods are rapid and highly effective ways to kill insects, but chemical agents have brought great pollution to the ecological environment, and the vulnerability of cultural relics restricts the use of chemical insecticides. At present, many long-acting and environment-friendly green insecticides have greatly improved traditional chemical methods. In addition, biological control methods that use biological natural enemies or parasitic organisms to control pests not only have small impacts on the ecosystem but also have a long-lasting effect, which is a hotspot in research on new pest control. However, whether the new species used to control the pests will do harm to cultural relics needs to be further studied. Pest control of cultural relics is a cross-research field, and the methods in architecture, agriculture and other fields have great enlightening significance and reference value. Finally, we discussed and prospected the current situation of common pest control research of unmovable cultural relics, hoping to provide a reference for the research of pest control in cultural relics.

【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.
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 Host plants and insects have formed complex defense and counter defense  mechanisms in the long-term co-evolution. In this article, we systematically reviewed the  process and mechanism of the mutual defense in host plant-piercing-sucking insect  interactions. The piercing-sucking insects use specialized needles to suck the sap of the  host plant tissue. Plants sense insect feeding signals through cell membrane surface or  intracellular receptors, and activate plant immunity through signal transduction pathways  such as mitogen-activated protein kinase (MAPK) signaling pathway, plant hormone signaling  pathway, calcium ion signaling pathway, transcription factor regulation, Rop/Rac GTPase  signaling pathway and reactive oxygen species (ROS) pathway. To prevent further insect  feeding, host plants form a strengthened physical barrier and induce the production of  secondary metabolites, anti-nutritional enzymes, anti-digestive enzymes and callose  deposition, and release volatiles and other defense mechanisms. In the process of “gaming ” with host plants, piercing-sucking insects often use secreted salivary components  during the feeding to target plant proteins. By destroying the physical barrier of host  plants, or inhibiting the resistance signal transduction of host plants, or inhibiting the  toxic effect of the host secondary metabolites, or by means of cross-border RNA and  horizontal gene transfer, piercing-sucking insects inhibit the plant defense response and  continue feeding to cause damage. In addition, based on the plant-pathogen interaction  model, and combined with the research advance of the host plant-piercing-sucking insect  interaction, we summarized the development of the interaction model between host plants and  piercing-sucking insects. Since the host plant-insect interaction is sophisticated, a  profound study on the mutual defense processes and molecular mechanisms of the host plant- piercing-sucking insect interaction will not only help deepen the understanding of their  co-evolution, but also help to provide theoretical foundation and references for  developing new approaches and technologies for crop insect pest control.

【Aim】 Blister beetles belonging to the family Meloidae within the order Coleoptera, are a series of resource insects with great medicinal value. The larval oligophagous and specialized feeding on locust eggs severely restricts their artificial rearing and the utilization and development of cantharidin. The larval obsession for food was universally acknowledged and proven by many studies, but we found through our rearing experiences that their feeding specialization gradually decreases during the whole larval stage. 【Methods】We conducted a large-scale rearing experiment and physiological and ecological analyses, determined the larval survival rate, pupation rate, adult eclosion rate, dry weight of mature larvae, growth amount, larval growth rate, larval duration, pupal duration, and number of eggs laid per female of Hycleus cichorii from various treatment groups (substituting locust eggs by the artificial diet from the 1st, 2nd, 3rd and 4th instars, i.e. 1st-4th instar groups, respectively) and the control group (fed with locust eggs throughout the larval stage), then compared the growth, development and adult reproduction of grouped meloids to verify the feeding adaptation of H. cichorii larvae to the non-preferred food and figure out the adaptive pattern to the nutritional stress. 【Results】After substituting locust eggs by the artificial diet, the 1st instar group had a significantly lower survival rate than the 2nd, 3rd and 4th instar groups and the control group, and a zero pupation rate. Moreover, after substituting locust eggs by the artificial diet, the 1st instar group had significantly lower larval growth rate and dry weight of mature larvae, and longer larval duration than the 2nd, 3rd and 4th instar groups and the control group. There was no significant difference in the survival rate among the 2nd, 3rd and 4th instar groups, but the pupation rate and adult eclosion rate gradually increased with instars increasing. After substituting locust eggs by the artificial diet, the larval growth rate and dry weight of mature larvae increased, and the larval duration shortened with instars increasing. 【Conclusion】 The results of this study suggest that the 1st instar larvae of H. cichorii can not adapt to the non-preferred food, while the older instar larvae manifest a stepwise improving feeding adaptation with instars. This study demonstrates that the food specialist H. cichorii larvae possess a staged adaptation to nutritional stress. The detailed pattern of changing feeding adaptability provides theoretical feasibility for the complete artificial rearing of H. cichorii larvae and will contribute to the studies on the artificial rearing and resource utilization of medicinal meloids.

 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.

【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.

【Aim】 To explore the effects of the heavy metal Cu²⁺ and the pesticide  avermectin and their combined stress on the growth and development and reproductive  behavior of the Asian corn borer, Ostrinia furnacalis in farmland.【Methods】 We added 50  mg/kg of Cu²⁺ and 0.039 mg/L of avermectin (LC₁₀ concentration against the 3rd instar  larvae of O. furnacalis) to the artificial diet, respectively, and simultaneously, and then  got three kinds of treated diets containing Cu²⁺ (Cu), avermectin (Av) and both (Av+Cu), 
taking the normal artificial diet as the blank control group. We fed the neonate larvae of  O. furnacalis with the four diets under laboratory conditions, and systematically  investigated and recorded the parameters of growth and development (larval duration, pupal 
duration, pupal weight, adult weight, growth rate, adult emergence rate and adult  longevity)， calling behavior (calling rate and average calling duration), orientation  behavior (take-off rate, orientation rate, average response time, flying halfway rate and  landing to pheromone source rate), and reproduction (number of eggs laid per female and egg  hatching rate).【Results】 Cu, Av and their combined stress (Av+Cu) had certain effects on  the growth and development and reproduction of O. furnacalis. On the one hand, the  postembryonic developmental duration (larval plus pupal duration) of female and male O.  furnacalis in Cu treatment alone was significantly shortened as compared to  that in the  blank control group. After Av treatment alone, the postembryonic developmental duration of  female and male O. furnacalis was significantly prolonged to 38.31 and 38.95 d,  respectively, being 67.07% and 67.38% longer than that of the blank control group,  respectively. After Cu treatment alone, the body weight of female pupae, male pupae, female  adults and male adults of O. furnacalis decreased significantly, being 13.16%, 6.45%,  7.13% and 4.60% lower than that of the blank control group, respectively. Then after Av  treatment alone, the body weight of female pupae, male pupae and female adults of O.  furnacalis decreased significantly, being 26.50%, 8.96% and 12.46% lower than that of the  blank control group, respectively, while the body weight of male adults was significantly  higher than that of the blank control group by 6.05%. At the same time, Cu treatment had a  certain impact on the calling behavior of female adults. After Cu treatment, the highest  calling rate and average calling duration in each scotophase decreased with the scotophase,  while those in the blank control group showed a trend of increasing first and then  decreasing with the scotophase. After Av treatment, the calling behavior of female adults  was promoted: the highest calling rates in all scotophases except the scotophase 5 (the 5th  scotophase after emergence of females) reached 100%; the average calling duration in Av  treatment groups was significantly longer than that in the blank control groups in all  scotophases except the scotophase 3 (the 3rd scotophase after emergence of females), and  the average calling duration in Av treatment group was the highest (5.71 h) in scotophase  5. Compared to the blank control group, Cu and Av treatment alone significantly inhibited  the orientation behavior of male adults and the number of eggs laid per female of O.  furnacalis. On the other hand, the effects of the combined stress of Av and Cu and their  single stresses were different. Compared to the blank control group, Av+Cu treatment  inhibited the growth and development of O. furnacalis, causing significant extension of the  developmental duration and body weight loss. The female and female postembryonic  developmental duration in Av+Cu treatment was 37.60 and 37.04 d, respectively, only shorter  than that in Av treatment. The body weight of female and male pupae and female adults in  the Av+Cu treatment group was the lowest, significantly lower than that in the blank  control group. In the mating combinations of female and male adults stressed by Av+Cu and  female and male adults in the blank control group, the landing to pheromone source rate of  male adults and the number of eggs laid per female were significantly lower than those of  the mating combination of female and male adults in the blank control group, and both were  the lowest. The calling behavior of female adults of O. furnacalis after Av+Cu stress was  relatively consistent with that after Av treatment, and the highest calling rates in all  scotophases reached 100%. The average calling duration in each scotophase in Av+Cu  treatment group was significantly longer than that in the blank control group and Cu  treatment group, and showed no significant difference from that in Av treatment group, and  the average calling duration in Av+Cu treatment was the longest (6.16 h) in scotophase 3.【 Conclusion】Single and combined stresses of Cu and Av inhibit the growth and development,  disturb the reproductive behavior of adults and reduce the fecundity of O. furnacalis.  Among the effects of the combined stress of Cu and Av on O.furnacalis, Av plays a leading  role.

【Aim】 To analyze the differences in the midgut bacterial composition among different varieties of Bombyx mori with different vitalities and cocoon shell ratios, and their effects on the related traits such as vitality and cocoon shell ratio. 【Methods】 Based on the results of the long-term feeding survey on B. mori resource, the variety 932G with high vitality and the variety 2041J with high silk yield were selected as experimental materials, the midguts of the 5th instar larva and pupa were collected, and the 16S rDNA sequences of the midgut bacteria were sequenced and analyzed by the high-throughput sequencing platform to compare the differences in the composition and function of the midgut bacteria between different varieties and different developmental stages of B. mori. 【Results】 A total of 399 and 453 operational taxonomic units (OTUs) of the midgut bacteria were obtained from 932G and 2041J at the 5th instar larval stage, and 138 and 162 OTUs of the midgut bacteria were obtained from 932G and 2041J at the pupal stage, respectively. The dominant phyla of the midgut bacteria of B. mori at the 5th instar larval stage were Proteobacteria, Firmicutes and Actinobacteriota, and the dominant genus was Methylobacterium with the highest abundance, followed by Staphylococcus. However, there were significant differences in the relative abundance of some genera between the two varieties. The relative abundance of some genera including Devosia, Ralstonia, Nitrospira, Brachybacterium, Rothia, Lawsonella etc. in the midgut of the 5th instar larva of 932G was significantly higher than that in the midgut of the 5th instar larva of 2041J. The relative abundance of Pseudomonas, Methylobacterium, Acinetobscter, Cloacibacterium, Leuconostoc, Propionibacteriaceae, Psychrobacter, Sphingobium, Bacteroides etc. in the midgut of the 5th instar larva of 2041J was significantly higher than that in the midgut of the 5th instar larva of 932G. There were 77% and 78% functional genes in the midgut bacteria of the 5th instar larvae of 932G and 2041J enriched on the metabolic pathways of KEGG, respectively, followed by those of the function genes enriched on the environmental information processing and genetic information processing. The proportions of the midgut bacterial communities involved in nitrate reduction, nitrogen respiration, nitrate respiration, nitrite respiration and nitrogen fixation in the 5th instar larva of 932G were higher than those in 2041J. The proportions of the midgut bacterial communities involved in chemical heterotrophic, urea decomposition and methanol oxidation in the 5th instar larva of 2041J were higher than those in the 5th instar larva of 932G. The difference in the midgut bacterial composition between the 5th instar larva and pupa was significant. Erwinia of Proteobacteria in the midgut of the pupa was the dominant genus, and there was no significant difference in the relative abundance of Erwinia between the two varieties at the pupal stage. The relative abundance of functional genes involved in amino acid transport and metabolism, extracellular secretion and transport, carbohydrate transport and metabolism, and inorganic salt transport and metabolism of the midgut bacteria in the pupa was significantly higher than that in the 5th instar larva of 932G.【Conclusion】 There were significant differences in the midgut bacterial composition and predicted function between the varieties 932G with high vitality and 2041J with high silk yield of B. mori at the 5th instar larval stage. The composition and function of the midgut bacteria of B. mori at the pupal stage were significantly different from those of B. mori at the 5th instar larval stage, and there was no significant difference in the relative abundance of midgut bacteria between the two varieties at the pupal stage. These research results can provide a reference for further exploring the role of gut microorganisms in stress resistance, drug resistance, disease resistance, protein synthesis and transformation of B. mori and variety breeding.

【Aim】To observe the ovarian developmental progress and formulate ovarian developmental grading criteria of Conopomorpha sinensis, explore the influence of mating on the ovarian developmental progress and fecundity. 【Methods】 The newly eclosed female and male adults of C. sinensis were paired in a 1∶1 ratio and reared. The female ovaries were dissected daily, and the mating experience was judged according to the characteristics of the bursa copulatrix. The characteristics of fat body, length of ovarioles, total number of egg chambers and number of mature eggs of mated and unmated females were recorded for grading the ovarian development progress. The newly eclosed female and male adults paired in a 1∶1 ratio, and newly eclosed female adults that were individually reared were used as the mated group and unmated group, respectively, and the pre-oviposition period, oviposition period, number of eggs laid per female and female adult longevity were counted in the two groups.【Results】 The ovarian development of C. sinensis could be divided into five stages, including yolk deposition prophase (stage Ⅰ), yolk deposition phase (stage Ⅱ), egg maturation phase (stage Ⅲ), peak phase of oviposition (stage Ⅳ) and terminal phase of oviposition (stage Ⅴ). Only the ovaries of the mated female adults could completely develop. Otherwise, the ovaries of the unmated female adults only developed into the yolk deposition phase (stage Ⅱ). The preoviposition period, oviposition period, number of eggs laid per female and female adult longevity in the mated group were 3.82 d, 11.23 d, 176.42 grains and 16.35 d, respectively. The female adults in the unmated group could not lay eggs for life, and the female adult longevity in the unmated group was 20.48 d. 【Conclusion】 The ovarian development of C. sinensis adults can be divided into five stages. However, mating is a prerequisite for the completion of ovarian development of the female adult. The ovarian development of the unmated female adults terminates after reaching stage Ⅱ. The fecundity of the mated female adults is significantly higher than that of the unmated females, and the unmated females can not lay any eggs for life.

【Aim】To elucidate the function of Niemann-Pick type C2 protein of Varroa destructor (VdesNPC2b) in host recognition by analyzing the binding properties and mechanisms of VdesNPC2b with the larval pheromones methyl oleate and β-ocimene of the host bees of V. destructor, so as to provide a theoretical basis for biological control of V. destructor. 【Methods】 The open reading frame (ORF) of VdesNPC2b was amplified and analyzed using bioinformatics. The prokaryotic expression vector was constructed based on pET-30a plasmid. The recombinant VdesNPC2b protein was obtained by prokaryotic expression and affinity column chromatography. The binding capacities of VdesNPC2b with the larval pheromones of bees methyl oleate and β-ocimene were analyzed by fluorescence competitive binding experiment, and the binding mechanism of them was analyzed by measuring the binding capacity change at two different temperatures (22 and 32 ℃) through fluorescence spectrum temperature variation experiment. The homologous modeling of VdesNPC2b was performed by SWISS-MODEL software, and the molecular docking simulation of VdesNPC2b and β-ocimene was performed by MVD to preliminarily analyze the key amino acid sites in the binding of VdesNPC2b and β-ocimene. 【Results】 The ORF of VdesNPC2b (GenBank no.: OR463903) is 531 bp in full-length, encoding 176 amino acids. VdesNPC2b has a signal peptide of 16 amino acid residues at the N-terminus. The fluorescent competitive binding assay result showed that the dissociation constant K _D values of VdesNPC2b with methyl oleate and βocimene were 2.89 and 3.49 μmol/L, respectively, with the binding process of dynamic quenching, and the main driving forces maintaining the interaction between VdesNPC2b and methyl oleate and β-ocimene was hydrophobic force. Homologous modeling showed that the secondary structure of VdesNPC2b is β-sheet, and forms a potential external cavity. Leu68, Ile103 and Phe107 could be the key amino acid sites to maintain a stable form of the binding of VdesNPC2b and β-ocimene. 【Conclusion】 V. destructor may use VdesNPC2b binding long-chain brood ester pheromone methyl oleate and volatile β-ocimene to locate and identify host honey bee.

【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】The purpose of this study is to explore whether glutamate-gated chloride channels (GluCls) of the beet armyworm, Spodoptera exigua (SeGluCls) encoded by different transcription variants of SeGluCl have different susceptibilities to insecticides using CRISPR/Cas9 gene editing technology. 【Methods】 The full-length cDNA sequence of SeGluCl from S. exigua was obtained using RT-PCR and RACE, and analyzed by bioinformatics. Two splicing variants SeGluCl 3a and SeGluCl 3b of SeGluCl were knocked out by CRISPR/Cas9 gene editing technique, and two knockout strains (3a-KO and 3b-KO) of S. exigua were established. The difference in the susceptibilies of the 3rd instar larvae of the susceptible strain WH-S (control strain) and 3a-KO and 3b-KO strains to three insecticides abamectin, emamectin benzoate and fipronil was determined by bioassay. 【Results】 The full-length cDNA sequence of SeGluCl of S. exigua was obtained, and its two splicing variants (SeGluCl 3a and SeGluCl 3b) were found. The open reading frame (ORF) of SeGluCl 3a (GenBank accession no.: OM304353) is 1 362 bp in length encoding 454 amino acids. The ORF of SeGluCl 3b (GenBank accession no.: OM304354) is 1 365 bp in length encoding 455 amino acids. The two SeGluCls encoded by the splicing variants SeGluCl 3a and SeGluCl 3b contain four transmembrane regions and one cysteine loop. Phylogenetic analysis indicated that SeGluCl was most closely related to GluCls of S. litura and S. frugiperda. Compared to the control strain WH-S, the knockout strains (3a-KO and 3b-KO) showed no significant difference in the susceptibilities to abamectin, emamectin benzoate and fipronil. 【Conclusion】 There is no difference in the susceptibility of SeGluCls encoded by the splicing variants SeGluCl 3a and SeGluCl 3b of SeGluCl to the three insecticides abamectin, emamectin benzoate and fipronil in S. exigua.

【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 objective of this study is to unravel the regulatory role of ame-miR-14 in the developmental process of the larval guts of Apis mellifera ligustica workers.【Methods】 The expression and sequence authenticity of ame-miR-14 in the 6-day-old larval guts of A. m. ligustica workers were proved by Stem-loop RT-PCR and Sanger sequencing, respectively. Overexpression and knockdown of ame-miR-14 were conducted by feeding its corresponding mimic (mimic-ame-miR-14) and inhibitor (inhibitor-ame-miR-14), and their corresponding negative controls mimic-NC and inhibitor-NC, respectively, and then RT-qPCR was used to detect the expression levels of ame-miR-14 in the 4-6-day-old larval guts of A. m. ligustica workers. Bioinformatic software was used to predict and analyze the target genes of ame-miR-14. RT-qPCR was employed to detect the relative expression levels of the target genes FoxO and Hedgehog in the 4-6-day-old larval guts after overexpression and knockdown of ame-miR-14.【Results】 ame-miR-14 truly exists and is expressed in the 6-day-old larval guts of A. m. ligustica workers. The expression levels of ame-miR-14 in the 4-6-day-old larval guts of A. m. ligustica workers fed with mimic-ame-miR-14 were significantly up-regulated as compared to those fed with mimic-NC. The expression levels of ame-miR-14 in the 4-6-day-old larval guts of A. m. ligustica workers fed with inhibitor-ame-miR-14 were significantly down-regulated as compared to those fed with inhibitor-NC. In total, ame-miR-14 can target 309 genes, which could be annotated to 45 KEGG pathways and 36 GO terms. Further analysis showed that ame-miR-14 can target 14 genes associated with growth and development and have potential targeting relationship with target genes FoxO and Hedgehog. After overexpression of ame-miR-14, the expression level of FoxO in the 4dayold larval gut of the mimic-ame-miR-14 group was down-regulated and those in the 5- and 6-day-old larval guts significantly down-regulated as compared to those in the mimic-NC group. After knockdown of ame-miR-14, the expression level of FoxO in the 4-day-old larval gut of the inhibitor-ame-miR-14 group was down-regulated, while that in the 5-day-old larval gut was significantly up-regulated and that in the 6-day-old larval gut was up-regulated as compared to those in the inhibitor-NC group. After overexpression of ame-miR-14, the expression levels of Hedgehog in the 4-6-day-old larval guts of the mimic-ame-miR-14 group were significantly down-regulated in comparison with those in the mimic-NC group, whereas those in the 4-6-day-old larval guts of the inhibitor-ame-miR-14 group were up-regulated in comparison with those in the inhibitor-NC group. 【Conclusion】ame-miR-14 truly exists and is expressed in the larval guts of A. m. ligustica workers. Effective overexpression and knockdown of ame-miR-14 in the larval guts of A. m. ligustica workers can be achieved by feeding mimic and inhibitor, respectively. ame-miR-14 potentially participates in regulation of the larval gut development by negatively regulating the expression of FoxO and Hedgehog.

【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.