【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.

 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.

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

【Aim】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】 To reveal the role of the superoxide dismutase genes in Liposcelis bostrychophila in response to high and low temperature stresses. 【Methods】The cDNAs of three superoxide dismutase genes Cu/Zn-SOD1, Cu/Zn-SOD2 and Fe/Mn-SOD of L. bostrychophila were cloned by RT-PCR, and their sequence characteristics were analyzed by bioinformatics methods. RT-qPCR was used to detect the relative expression levels of Cu/Zn-SOD1, Cu/Zn-SOD2 and Fe/Mn-SOD in adults at 0, 1 and 2 h under high temperature (42 ℃) and low temperature (4 ℃) stresses. 【Results】 LbCu/Zn-SOD1, LbCu/Zn-SOD2 and LbFe/Mn-SOD (GenBank accession numbers are OQ938782, OQ938783 and OQ938784, respectively) of L. bostrychophila were cloned, with the open reading frames (ORFs) of 465, 630 and 636 bp in length, encoding 154, 209 and 211 amino acids with the relative molecular weights of 15.85, 22.33 and 23.72 kD, and the isoelectric points of 6.17, 7.68 and 6.79, respectively. LbCu/Zn-SOD1 and LbCu/Zn-SOD2 had one and two Cu/Zn superoxide dismutase signatures, respectively. LbFe/Mn-SOD had one Fe/Mn superoxide dismutase signature. The results of phylogenetic analysis showed that Cu/Zn-SOD1, Cu/Zn-SOD2 and Fe/Mn-SOD were highly conserved in insects. The expression of LbCu/Zn-SOD1, LbCu/Zn-SOD2 and LbFe/Mn-SOD in adults of L. bostrychophila was induced by high temperature42 ℃ stress, and the expression levels of LbCu/Zn-SOD1 and LbCu/Zn-SOD2 inadults of L. bostrychophila were significantly higher than that of the control at 1 and 2 h. The expression level of LbFe/Mn-SOD in adults of L. bostrychophila was significantly lower than that of the control at 1 h and significantly higher than that of the control at 2 h under42 ℃stress. There was no significant difference in the expression levels of LbCu/Zn-SOD1 and LbCu/Zn-SOD2 inadults of L. bostrychophila at 1 h, while that of LbFe/Mn-SOD decreased significantly at 1 h and those of LbCu/Zn-SOD1, LbCu/Zn-SOD2 and LbFe/Mn-SOD increased significantly at 2 h under 4 ℃stress as compared with that of the control. 【Conclusion】 The superoxide dismutase genes LbCu/Zn-SOD1, LbCu/Zn-SOD2 and LbFe/Mn-SOD are involved in the tolerance of L. bostrychophila to extreme temperature stress.

【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.

 Insects are the most abundant and widespread group of animals in the world that harbor complex and diverse gut microbes. Different insects differ in gut structure, gut environment, edibility, age and external environment, and the composition and abundance of gut microbes also show difference. Insect gut microbes are mainly transferred vertically and horizontally between populations and individuals, and play a vital role in nutrient metabolism, physiological behaviour, defence, detoxification and many other functions in insect hosts. Insect gut microbes can be isolated from culture media by in vitro culture methods and rapidly identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and sequencing technologies such as 16S rRNA gene sequencing. The combination of metagenomics, proteomics, metabolomics and other omics technologies makes the identification and functional prediction of gut microbes more efficient. Microbial functions can be more accurately verified by in vitro experiments, microbial supplementation, microbiota transplantation and silencing of genes associated with microbial members. Sterile insects can be obtained by high temperature treatment, lysozyme treatment, sterile feeding and antibiotic treatment for functional verification experiments. However, the most widely used antibiotic method still has limitations in application. By exploiting the characteristics of gut microbes, genetic engineering of symbiotic bacteria can be used to control pests and insect-borne infectious diseases. At present, insect gut microbes play an important role in the fields of ecology, economy, energy and environmental protection. With the development and integration of new technologies, more insect-microbe interaction mechanisms will be revealed, and pest control methods through insect gut microbes will become more diverse, environmentally friendly and efficient.

【Aim】 The effective coordination between symbiont and host insect innate immunity is an important physiological basis for maintaining their reciprocal relationship. Rickettsia is a dominant symbiont in the whitefly, Bemisia tabaci. The aim of this study is to investigate the regulation of Rickettsia on the expression of the immune genes of B. tabaci adults at different day-old ages. 【Methods】 The expression levels of immune key factor lysozyme gene BtLyz1 and defensin gene Btdef in adult B. tabaci lines with 100% infection, 45.83% infection and no infection by the symbiont Rickettsia were detected and compared, respectively, using qRT-PCR. The expression levels of BtLyz1 and Btdef, apoptosis gene BtCaspase and Rickettsia 16S rRNA gene in 100% Rickettsia-infected adults newly emerged within 24 h and adults at the 3-7-day-old and over 15-day-old were detected, respectively, using qRT-PCR. The correlations between the expression level of 16S rRNA gene of Rickettsia and the expression levels of BtLyz1 and Btdef in B. tabaci adults at different day-old ages were analyzed. 【Results】 The expression levels of BtLyz1 and Btdef in B. tabaci adults infected with the symbiont Rickettsia were significantly increased as compared to those in B. tabaci adults non-infected with Rickettsia. The highest expression level of BtCaspase was observed in B. tabaci adults at over 15-day-old infected with Rickettsia. The expression levels of Rickettsia 16S rRNA gene, BtLyz1 and Btdef  in the 3-7-day-old adults of B. tabaci were significantly higher than those in adults newly emerged within 24 h and at over 15-day-old. The expression level of Rickettsia 16S rRNA gene was significantly positively correlated with the expression levels of BtLyz1 and Btdef in B. tabaci adults newly emerged within 24 h and at the 3-7-day-old, while there was no correlation between the expression level of Rickettsia 16S rRNA gene and the expression levels of BtLyz1 and Btdef in adults at over 15-day-old. 【Conclusion】 The symbiont Rickettsia can upregulate the expression levels of immune-related genes in the host B. tabaci. However, this regulatory effect decreases significantly when the host becomes aging.

【Aim】 Atrijuglans hetaohei, an important fruit pest of Juglans regia, is widely distributed among the main producing areas (Beijing, Shandong, Shanxi, Shaanxi, Sichuang, etc.) of J. regia inChina, seriously affecting the yield and quality of J. regia and causing serious economic losses. This study aims to investigate the genetic differentiation and geographic distribution characteristics of A. hetaohei, clarify its genetic structure among different geographical populations, understand the population dispersal pattern, and provide theoretical guidance for the prevention and control of this pest insect. 【Methods】 Based on the transcriptome sequencing result of A. hetaohei, the polymorphic microsatellite markers were selected using polyacrylamide gel electrophoresis and capillary electrophoresis typing methods to analyze the population genetic diversity of319 A. hetaohei individual samples from 16 populations in eight provinces/city (Beijing, Hebei, Henan, Shandong, Shanxi, Shaanxi, Gansu and Sichuan). Population genetic structure of A. hetaohei was analyzed using STRUCTURE and BAPS software, and the factors that affect the geographical distribution of A. hetaohei were also explored. 【Results】 Nine SSR loci of A. hetaohei exhibited high polymorphism, most of them did not deviate from Hardy-Weinberg equilibrium. The genetic diversity of A. hetaohei geographical populations was medium low (effective number of alleles Ne: 1.334－1.824; expected heterozygosity He: 0.203－0.342), the genetic differentiation between populations was small (genetic differentiation coefficient F_ST<0.142), and the gene flow among populations was significantly different (Nm: 1.518－23.800). There was a significant correlation (R²=0.226) between the degree of genetic differentiation and geographical distance among the populations. Sixteen geographical populations of A. hetaohei could be divided into two lineages (eastern and western lineages). AMOVA analysis showed a relatively small genetic variation among A. hetaohei populations, and population variation mainly originated from that within populations. The values of the fixation indice F_CT within A. hetaohei populations ranged from 0.03941 to 0.06449, indicating that geographical barriers and climatic differences were not the main factors affecting the genetic structure and geographical distribution pattern of A. hetaohei populations.【Conclusion】 A. hetaohei populations have a medium low genetic diversity, and a low level of genetic differentiation and a significantly different gene flow between populations. In view of the special life history and unique biological characteristics of A. hetaohei, combining with the population genetic structure analysis result, we speculate that rivers form a stronger blocking effect on the gene flow of the geographical populations of A. hetaohei than mountains. As a major pest of economic tree, human activities are possibly the main factor which affects the geographical distribution of A. hetaohei populations.

Rice, as a major staple crop in China, is directly threatened by disease and pest infestations, which jeopardize its safe production. Rice pests are diverse, and their outbreak mechanisms are complex, making the development of green control technologies challenging. Indepth research into rice pest monitoring and early warning technologies, developmental and reproductive regulation mechanisms, chemical communication mechanisms, and novel control technologies not only helps elucidate the outbreak mechanisms of rice pests but also provides new effective control targets and techniques for integrated pest management. In recent years, Chinese scholars have made significant progress in the field of rice pest research, gaining important achievements in multiple research directions, and some recent research findings were presented in this special issue. In this article, we outline the latest progresses in rice pest research at home and abroad, introduce the main research contents of this special issue, and propose the following three research directions worthy of further attention: (1) intelligent monitoring and early warning of rice pests; (2) mechanisms and evolution patterns of rice pest outbreaks; and (3) exploration of green control targets for rice pests and the construction and application of sustainable control systems.

 Apis cerana cerana is a critical and important pollinator in China. This bee species has a wide distribution in various habitats, and exhibits several advantages as pollinator, e.g., agility in flight, long nectar gathering period and strong adaptability. However, in recent years, A. c. cerana has been facing an unprecedented decline in population diversity. In order to protect the genetic resources of these specific populations, researchers studied the physiology and mechanism of genetic differentiation and environmental adaptation in A. c. cerana based on geometric morphology, molecular biology and genomics technologies. Meanwhile, the diverse populations of A. c. cerana in China provided rich materials for analyzing their adaptive evolution. In this article, we summarized the research progress from the four aspects: The correlation between population genetic differentiation and environmental changes, the morphological variation and environmental adaptation, the enviroment-adaptive physiological and behavioral changes, and the genetic mechanisms behind these phenotypic changes of A. c. cerana populations. Previous studies showed that changes in physical barriers and ecological environment, especially those related to altitude and latitude, were the main reasons for the differentiation of A. c. cerana populations. Among the climatic factors, temperature, oxygen, radiation and humidity had important effects on the morphological development and eco-physiological traits of A. c. cerana. The morphological changes were mainly explained by variation in body size and color. Changes in metabolic physiology and behaviors have been evolved as a crucial adaption strategy. Population genetics and genomics based on modern genomics and molecular biology techniques showed that genes and pathways related to social division of labor, learning and perceiving behavior, information perception, growth and development, thermal adaptation and metabolism are subject to natural selection. These findings provide molecular evidence for the ability of A. c. cerana to adapt to different habitats and the evolution of bee species. However, the specific molecular evolution mechanisms for the environmental adaption of bees await further investigation. Our review on the mechanisms of genetic differentiation and environmental adaption of A. c. cerana will deepen our understanding of the evolutionary history and genetic diversity of ancient bee species, and lay a foundation for further studies on the adaptive mechanisms of social insects to different environments and the development of effective conservation strategies.

【Aim】 To clarify the defense mechanism of Ostrinia furnacalis against cadmium and chlorantraniliprole, and to evaluate the cumulative effects of heavy metals and pesticide pollution on insects. 【Methods】 The newly hatched larvae of O. furnacalis were fed with the artificial diet containing 5 mg/kg cadmium, 0.003 mg/kg chlorantraniliprole and 5 mg/kg cadmium+0.003 mg/kg chlorantraniliprole, respectively, and those fed with the normal artificial diet were used as the control. The developmental duration, body weight, adult emergence rate and abnormal pupal rate were recorded, and the activities of detoxification enzymes including glutathione-S-transferase (GST), carboxylesterase (CarE) and acetylcholinesterase (AChE) in O. furnacalis at different developmental stages (3rd instar larva, female and male pupae, and female and male adults) were detected. 【Results】 Cadmium (5 mg/kg), chlorantraniliprole (0.003 mg/kg), and their combined treatment (5 mg/kg cadmium+0.003 mg/kg chlorantraniliprole) had effects on the growth and development of O. furnacalis. In chlorantraniliprole treatment group, the larval duration of O. furnacalis was the longest, significantly prolonged by 7.1 d as compared to that in the control group, and the pupal weight, adult weight and adult emergence rate of O. furnacalis were the lowest, significantly decreased by 9.1 mg, 2.4 mg and 25.5% as compared with those in the control group. In cadmium+chlorantraniliprole treatment group, the larval duration of O. furnacalis was 4.9 d shorter than that in chlorantraniliprole treatment group, and the abnormal pupal rate was the highest, significantly increased by 19.4% as compared to that in the control group. The adult duration of O. furnacalis in cadmium+chlorantraniliprole treatment group was the shortest, significantly reduced by 1.6 d as compared to that in the control group. Cadmium, chlorantraniliprole and cadmium+chlorantraniliprole had effects on the detoxification enzyme activities in O. furnacalis. Compared with the control, cadmium, chlorantraniliprole and cadmium+chlorantraniliprole showed inducing effects on the GST activities in the 3rd instar larvae, female and male pupae and male adults of O. furnacalis, and the GST activities in different developmental stages of O. furnacalis in cadmium+chlorantraniliprole treatment group were significantly higher than those in the other treatment groups and the control group. Compared with the control, cadmium, chlorantraniliprole and cadmium+chlorantraniliprole showed inhibitory effects on the CarE activities in different developmental stages of O. furnacalis, and the cadmium+chlorantraniliprole treatment had the strongest inhibitory effect on the CarE activities in various developmental stages of O. furnacalis. Compared with the control, cadmium, chlorantraniliprole and cadmium+chlorantraniliprole showed inducing effects on the AChE activity in the 3rd instar larvae of O. furnacalis, but had different effects on the AChE activities in the pupae and adults. 【Conclusion】 Cadmium (5 mg/kg), chlorantraniliprole (0.003 mg/kg) and their combined treatment can all affect the growth and development of O. furnacalis, and have different effects on its detoxification enzyme activities.

Lures can stimulate the behavioral responses of fruit flies to a certain extent and play an important role in the green prevention and control of fruit flies. As one of the most important lures, and coming from some plant volatiles or parapheromones, male lures of fruit flies have a significant attractive effect on male fruit flies. Male fruit flies will not only be attracted by the smell of male lures but also feed on the lures, which will be metabolized into different substances in male adults, and then play the corresponding function. In this review, combined with the studies on the feeding effects, we reviewed the research progress of six male lures of fruit flies, namely methyl eugenol, raspberry ketone, zingerone, cuelure, 3-hydroxy-α-ionone and β-caryophyllene, and their metabolism, mainly including the feeding behavior and metabolic changes of male fruit flies, the influence of feeding effect on the behavioral responses of fruit flies, the attractive effect of male fruit flies fed on lures on female and male fruit flies, and the change of mating success rate. In the exploration of the feeding effect, rectal gland is the focus of pheromone isolation and storage, and the waxy, water-resistant film composed of hydrocarbons covering insect body surface is also a potential focus of research. At the same time, exploring the role of antennae and maxillary palp in the lure perception process of fruit flies will help to reveal the complex mechanism behind feeding phenomenon more comprehensively and profoundly. It is expected to provide new ideas and guidelines for the development of fruit fly lures and add more diversified means and approaches for the green ecological prevention and control of fruit flies.

【Aim】 Aphidius gifuensis, as a dominant parasitic wasp of Myzus persicae, has been widely used in production. However, during the propagation of A. gifuensis on a large scale, many problems such as reduced parasitic ability and smaller body size often occur after multiple generations of breeding. The purpose of this study is to screen the best rejuvenation methods by detecting and analyzing the effects of supplementing different concentrations of nutrients and trace elements on the parasitism rates and offspring adult size of A. gifuensis adults on M. persicae, and the contents and activities of growth and development-related enzymes in adults of the offspring of A. gifuensis. 【Methods】 A. gifuensis adults of the degenerated population after being reared in laboratory for 10 generations were fed with solutions of different concentrations (5%, 10% and 20%) of nutrients (honey, glucose and sucrose), and different concentrations (0.25, 0.5, 1, 2 and 4 mg/L) of trace elements including Cu, Fe, Zn, Mn and Co, the parasitism rate and offspring adult size, and the contents and activities of carboxylesterase(CarE)and phenoloxidase (PO) in adults of the offspring were determined. 【Results】 In supplemental nutrition experiments, 10% honey solution had the best rejuvenation effect on A. gifuensis, causing the parasitism rate to increase by 28.00% compared with the control (purified water), but had no significant effect on the offspring adult size. In the group fed with 10% glucose, the CarE content in adults of the offspring of A. gifuensis was the highest, which was 38.00% higher than that in the control group. The CarE activity in adults of the offspring of A. gifuensis in the group fed with 10% sucrose was the highest, which was 3-fold as high as that in the control group. In the group fed with 10% sucrose, the phenoloxidase content in adults of the offspring of A. gifuensis was the highest, which was 56.00% higher than that in the control group. The highest phenoloxidase activity in adults of the offspring of A. gifuensis was found in the group fed with 10% glucose, being 1.3-fold as high as that in the control group. In supplemental trace element experiments, the supplementation of 1 mg/L Fe had the best rejuvenation effect on A. gifuensis, resulting in the parasitism rate to increase by 25.33% compared with the control group, but had no significant effect on the offspring adult size. The CarE content in adults of the offspring of A. gifuensis in the group fed with 1 mg/L Fe was the highest, which was increased by 50.00% as compared with that in the control group. The CarE activities in adults of the offspring of A. gifuensis in groups fed with various trace elements were lower than that in the control group. In the group fed with 1 mg/L Zn, the PO content in adults of the offspring of A. gifuensis was the highest, increased by 29.31% as compared with that in the control group. In the group fed with 1 mg/L Mn, the PO activity in adults of the offspring of A. gifuensis was the highest, which was 1.51-fold as high as that in the control group. 【Conclusion】 In production, feeding 10% honey solution or supplementing 1 mg/L Fe can be used to improve the parasitic ability of A. gifuensis on M. persicae, so as to restore or regulate the degenerated population of A. gifuensis.

 Honeybee queens share the same genetic background with the workers, and they both are developed from fertilized eggs. Nutritional and spatial variances during the development lead to significant morphological, physiological and behavioral dimorphism between the two castes. The insulin signaling pathway (IIS) regulates the behavior of worker bees, thus influencing their longevity. Longer longevity of queen bees is associated with increased oxidative stress and enhanced stress defense. Vitellogenin (Vg) interacts with juvenile hormone (JH), and the relatively high level of Vg and low level of JH usually lead to longer longevity. Telomerase activity and telomere length are influenced by the development and caste of honeybees. Queens inherit longer telomere length and maintain higher telomerase activity than workers. Overwintering worker bees live longer and show higher telomerase activity than the summer worker bees. Mitochondrial damage is a sign of senescence, while the mitochondrial function of the aged queen remains vigorous. Senescence is closely related to DNA methylation, and DNA methylation and histone modification play important roles in the regulation of plasticity in social insects. With the increase in population aging and the high prevalence of senescence-related diseases, “healthy aging” has triggered a series of concerns in life sciences and social sciences. Studies on honeybee senescence and longevity regulation will provide an important reference for the biology of senescence.

 【Aim】To clarify the effects of low concentrations of imidacloprid on the olfactory behavior of Hippodamia variegata adults. 【Methods】The behavioral responses of H. variegata adults to healthy cotton plants and adult Aphis gossypii-infested cotton plants after ingestion of low concentrations (LC₂₀ and LC₅₀) of imidacloprid were evaluated by a Y-olfactometer, while the volatiles from healthy and adult A. gossypii-infested cotton plants were collected separately by solid-phase microextraction and analyzed by gas chromatography-mass spectrometer to identify the volatile components. In addition, the response of H. variegata adults to each volatile component was further tested. 【Results】In the absence of imidacloprid ingestion, H. variegata adults showed a significant positive preference for adult A. gossypii-infested cotton plants, but had no significant tendency to healthy cotton plants or clean air. Besides, H. variegata adults that ingested imidacloprid at low concentrations had no significant tendency to adult A. gossypii-infested cotton plants, healthy cotton plants, or clean air. We identified eight significantly increased volatile compounds from the volatiles of adult A. gossypii-infested cotton plants compared with healthy cotton plants, including myrcene, limonene, 1-decyne, 3-carene, (3E)-4, 8-dimethyl-1, 3, 7-nonatriene (DMNT), β-caryophyllene, α-humulene and (3E,7E)-4, 8, 12-trimethyltrideca-1, 3, 7, 11-tetraene (TMTT). The olfactory selection behavior of H. variegata adults to the above eight compounds measured with Y-olfactometer illustrated that H. variegata adults without imidacloprid ingestion had a significant positive tendency towards TMTT and no significant tendency to the other seven volatile compounds, while H. variegata adults that ingested imidacloprid at low concentrations had no significant positive preference for any of the eight volatile compounds. In the behavioral selection tests, the numbers of unselected individuals in H. variegata adults treated with low concentrations of imidacloprid to both volatiles from cotton plants and their single components were significantly higher than that of the control.【Conclusion】 Our results revealed that low concentrations of imidacloprid weakened the olfactory recognition of cotton plant volatiles by adult H. variegata, providing a scientific basis for the conservation and utilization of H. variegata and the rational use of pesticides in Xinjiang cotton fields.

【Aim】This study aims to investigate the molecular characteristics, expression patterns, and biological functions of the mucin-like protein EfMLP genes of Empoasca flavescens. 【Methods】Based on the transcriptome data of E. flavescens, the full-length cDNA sequences of four EfMLP genes were cloned by PCR and analyzed by bioinformatics. qRT-PCR was used to detect the expression levels of EfMLP genes across different developmental stages (egg, 1st-5th instar nymphs, and newly emerged female and male adults), and in different tissues (integument, fat body, salivary gland, gut, ovary, and testis) of the newly emerged adults. EfMLP2 and EfMLP4 in the 5th instar nymph were silenced by RNAi through feeding method, and the survival rates of E. flavescens after silencing the EfMLP genes by RNAi were determined by bioassay. 【Results】 The full-length cDNA sequences of four EfMLP genes of E. flavescens were obtained, and named EfMLP1, EfMLP2, EfMLP3 and EfMLP4 with the GenBank accession numbers of OR504428, OR504429, OR504430 and OR504431, respectively. The obtained four EfMLPs all contain highly repetitive tandem repeat sequences, which are rich in O-linked glycosylation sites, forming the mucin domain (MD). Among them, both EfMLP3 and EfMLP4 contain a conserved type-2 chitin binding domain (CBD). Phylogenetic analysis result revealed that EfMLPs were divided into two different branches belonging to two different MLP types, which showed no correlation with insect taxonomy, but might be considered to be related to their functions. EfMLP1 and EfMLP2 exhibited specifically high expression in the newly emerged female and male adults and the salivary glands of the newly emerged adults. In contrast, the expression of EfMLP3 and EfMLP4 was identified in various developmental stages, including egg, nymphal and adult stages, as well as in diverse tissues such as the fat body of the newly emerged adult. Inhibition of the expression of EfMLP2 and EfMLP4 in E. flavescens by feeding dsEfMLP2 and dsEfMLP4 significantly reduced the survival rate of E. flavescens compared with the control group fed with dsGFP. 【Conclusion】 EfMLPs play an important role in the feeding of E. flavescens and can be used as a potential target in control of this pest insect based on RNAi strategies.

【Aim】 Prokaryotic expression of EoCarE592, a carboxylesterase (CarE) gene from Ectropis obliqua, and exploration of the ability of the recombinant protein to degrade pesticides.【Methods】 The prokaryotic expression vector pET-32a-EoCarE592 was constructed to be transformed to the Escherichia coli BL21 for heterologous expression. The recombinant protein was identified by SDS-PAGE and Western blot, and the inclusion body protein was denatured and renatured. The enzyme activity of the recombinant EoCarE592, and the effects of the temperature, pH, and metal ions on the enzyme activity were determined by using the content standard curve of solid blue B salt colorimetry. Gas chromatography was used to detect the degradation ability of EoCarE592 under pH 7.0 at30 ℃and 0, 4, 8, 12, 16, 20 and 24 h to 200 mg/L lambda-cyhalothrin, methyl-parathion and isoprocarb. 【Results】Recombinant EoCarE592 inclusion body protein was obtained through heterologous expression in E. coli. After urea renaturation, the recombinant EoCarE592 with the enzyme activity of 29.8 U was obtained. The optimal temperature and pH were determined to be around30 ℃and 7.0‒8.0, respectively, and Mg²⁺and K⁺ had a promoting effect on the enzyme activity of EoCarE592. Recombinant EoCarE592 can degrade lambda-cyhalothrin, methyl-parathion and isoprocarb at an initial concentration of 200 mg/L within 24 h at30 ℃, pH 7.0, with the degradation rates of 81.30%, 83.94%, and 79.83%, respectively.【Conclusion】The carboxylase EoCarE592 can degrade lambda-cypermethrin, methyl parathion, and isoprocarb, and  may be involved in the detoxification process of E. obliqua. This study lays a foundation for the degradation of pesticide residues in the environment and fruits and vegetables.

【Aim】 To determine the expression level changes of microRNAs (miRNAs) of Apis mellifera during the overwintering period, explore the potential relationships between miRNAs and their target mRNAs and cold resistance, so as to further reveal the molecular mechanism of cold resistance of A. mellifera at the miRNAomics level. 【Methods】 sRNA-seq technology was used to identify miRNAs in four subspecies of A. mellifera including A. m. ligustica, A. m. mellifera, A. m. caucasica and A. m. carnica during the early and middle overwintering periods. The differentially expressed miRNAs (DEmiRNAs) in the four subspecies during different overwintering periods were screened by P≤0.05 and |log₂ fold change|≥1. The screened target mRNAs of miRNAs were predicted using related bioinformatic software, and then annotated by GO and KEGG databases. The regulatory network of DEmiRNAs with target mRNAs was constructed according to the targeted binding relationship, followed by visualization with Cytoscape. Eight DEmiRNAs including ame-miR-263a-5p, ame-miR-184-3p, ame-miR-263b-5p, ame-miR-190-5p, ame-miR-6052-5p, ame-miR-9a-5p, ame-miR-100-5p and ame-miR-306-5p were randomly selected for RT-qPCR validation.【Results】A total of 210 miRNAs were predicted in the four subspecies of A. mellifera during the overwintering period, including 178 conserved miRNAs and 32 new miRNAs. The length of miRNAs in the four subspecies of A. mellifera ranged from 18 to 30 nt, of which the most distributed lengths are 22 and 23 nt, and the number of miRNAs with the first base U is the largest. DEmiRNAs with the highest expression level were ame-miR-1-3p, ame-miR-276-3p and ame-miR-184-3p in the four subspecies of A. mellifera during the early and middle overwintering periods. A total of 22 DEmiRNAs were screened from A. m. ligustica between the early and middle overwintering periods, targeting 394 mRNAs which were annotated to 161 GO functional terms and 16 KEGG pathways. A total of 28 DEmiRNAs were screened from A. m. mellifera between the early and middle overwintering periods, targeting 415 mRNAs which were annotated to 147 GO functional terms and 15 KEGG pathways. A total of 67 DEmiRNAs were screened from A. m. caucasica between the early and middle overwintering periods, targeting 1 021 mRNAs which were annotated to 171 functional GO functional terms and 21 KEGG pathways. A total of 18 DEmiRNAs were screened from A. m. carnica between the early and middle overwintering periods, targeting 330 mRNAs which were annotated to 147 GO functional terms and 13 KEGG pathways. A complicated regulatory network was formed between DEmiRNAs and target mRNAs in the four subspecies of A. mellifera. RT-qPCR results demonstrated that the expression trend of the eight DEmiRNAs was consistent with the data by sRNA-seq, which confirmed the reliability of our sequencing data.【Conclusion】The miRNA expression level changes in the four subspecies of A. mellifera during different overwintering periods were clarified, and several candidate molecular target miRNAs with potential regulation of cold resistance of A. mellifera were obtained, among which ame-miR-14-3p and ame-miR-3786-5p negatively regulate the expression of multiple mRNAs in A. m. mellifera, A. m. caucasica and A. m. carnica, but not in A. m. mellifera. miRNAs are involved in the cold resistance of A. mellifera by regulating the expression of target genes involved in glycerophospholipid metabolism, MAPK signaling pathway and mTOR signaling pathway.

【Aim】 To clarify the effects of the medium lethal concentration (LC₅₀) of avermectin on the development of short-term resistance of Psylla chinensis to avermectin. 【Methods】 The LC₅₀ value of avermectin to the 3rd instar nymphs of the field population (F) of P. chinensis was determined at 24 h after treatment by leaf-dipping method. Based on the F population, the relative avermectin-sensitive strain (SS), the field resistant strain from the F population after exposure to LC₅₀ of avermectin for six consecutive generations (FR) and the field control strain from the F population without exposure to avermectin for six consecutive generations (FS) of P. chinensis were established under indoor conditions. The resistance ratios of the 3rd instar nymphs of the F population and various strains of P. chinensis to avermectin were measured, and the developmental duration and survival rate of each developmental stage, and adult longevity and numbers of eggs laid per female of various strains were measured to construct a two-sex life table. 【Results】 The LC₅₀ values of avermectin to the 3rd instar nymphs of the F population and the SS strain of P. chinensis at 24 h after treatment were 2.458 and 0.706 mg/L, respectively. The resistance ratios of the 3rd instar nymphs of the F population, FR strain and FS strain to avermectin were 3.458, 11.965 and 1.782-fold, respectively. The developmental duration and survival rate of each developmental stage, and adult longevity and number of eggs laid per female of the FR strain changed as compared with those of the FS strain and SS strain. The egg duration and nymphal duration of the FR strain were significantly longer than those of the FS strain and SS strain. The adult longevity of the FR strain was shorter than that of the FS strain and SS strain. The number of eggs laid per female of the FR strain was decreased by 57.000 and 74.300 grains, respectively, as compared with those of the FS strain and SS strain. The intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R₀) of the FR strain were also decreased as compared with those of the FS strain and SS strain. The relative fitness of the FR strain was 0.743, which was 0.807-fold as high as that of the FS strain. 【Conclusion】 The resistance level of P. chinensis to avermectin increased and the fitness decreased by continuous treatment with LC₅₀ of avermectin for six generations. Therefore, avermectin should not be continuously used in pear orchards in order to delay the increase of the resistance of P. chinensis to avermectin.

 【Aim】 To clarify the effects of broflanilide on the fitness and detoxification enzyme activities of Spodoptera frugiperda after multiple generations of selection and to provide a theoretical basis for the scientific and rational use of this insecticide. 【Methods】 The changes in the toxicity of broflaniliole to the 3rd instar larvae, the activities of detoxification enzyms (cytochrome P450 monooxygenase, glutathione S-transferase and carboxylesterase) in the 3rd instar larvae and the population fitness of S. frugiperda were determined after the newly hatched larvae were continuously exposed to 0.25 mg/L of broflanilide for 10 generations by the diet-overlay method. And the synergistic effects of three synergists (PBO, TPP and DEM) on broflanilide were determined in bioassay against the 3rd instar larvae of S. frugiperda. 【Results】 After 10 generations of selection by broflanilide, the exposed S. frugiperda population Bro-SEL developed 2.71-fold resistance to broflanilide, compared to the unexposed population UNSEL. At the same time, the fecundity and larval survival rate of the exposed population Bro-SEL were significantly decreased and the population parameters (intrinsic rate of increase, finite rate of increase and net reproductive rate) were also significantly decreased, as compared to those in UNSEL. The Bro-SEL population had the relative fitness of 0.35. The carboxylesterase activities in the 3rd instar larvae of Bro-SEL were significantly increased by 1.62- and 1.61-fold, respectively, when using α-NA and β-NA as the substrates, but the activities of cytochrome P450 monooxygenase and glutathione S-transferase in the 3rd instar larvae of Bro-SEL had no significant change as compared with those in the unexposed population UNSEL. Bioassay against the 3rd instar larvae of S. frugiperda revealed that both PBO and TPP had significant synergistic effects on broflanilide, with the synergistic ratios of 1.31 and 1.42, respectively.【Conclusion】 These results showed that there was little change in the toxicity of broflanilide to S. frugiperda population after 10 generations of selection by the insecticide broflanilide, indicating that S. frugiperda has a low risk of metabolic resistance to broflanilide, but the population development and reproduction of S. frugiperda have high fitness cost, and broflanilide is a good alternative agent for controlling S. frugiperda.

 A stable intestinal microbial internal environment is the result of the interaction between intestinal microbes and intestinal immune response. During the continuous feeding, the species and number of insect intestinal microbes constantly change, so a complex and dynamic homeostatic mechanism is formed between intestinal microbes and intestinal epithelial cells. Insect intestinal epithelial cells can sense beneficial and harmful conditions and use immunoregulatory pathways for dynamic regulation of microbial population homeostasis, such as the dual oxidase-reactive oxygen species (Duox-ROS) system and immunodeficiency (Imd) signaling pathways, which can sense the changes in the number of intestinal microbies and participate in the regulation of intestinal microbial homeostasis. In addition, the intestinal microbes can also indirectly play a role in homeostatic regulation by releasing corresponding effectors to regulate the behavior of the flora through quorum sensing (QS). Thus, in this article, we reviewed the roles of physical defense, immune signaling pathways and QS in the maintenance of insect intestinal microbial homeostasis, which will deepen the understanding of the interactions between intestinal tissues and intestinal microbes. In the future, we will continue to reveal the regulatory mechanisms of microbial homeostasis in more species of insects and the relationship between the regulatory mechanisms. In addition, new pesticides will be designed and developed to alter the homeostasis of intestinal microbes based on the regulatory mechanisms, which will provide new targets and ideas for the pest control.

【Aim】 Emamectin benzoate (EMB) is a novel antibiotic bio-derived insecticide and highly efficient in controlling lepidopteran pests. This study aims to investigate the sublethal effects of EMB on the rice pest of Hemiptera, Sogatella furcifera. 【Methods】 Using rice stem-dipping method, we first determined the LC₁₀, LC₂₅ and LC₅₀ values of EMB against the 3rd instar nymphs of S. furcifera reared for 72 h on the rice seedlings treated with EMB at different concentrations. The 3rd instar nymphs of S. furcifera were reared on rice seedlings treated with EMB at the LC₁₀, LC₂₅ and LC₅₀ concentrations for 48 h through the rice stem-dipping method. The female adult longevity and the number of eggs laid per female of the F₀ generation were determined. The duration of egg and the 1st-5th instar nymphs, adult longevity, pre-adult duration, total developmental duration, adult pre-oviposition period, adult total preoviposition period, and the number of eggs laid per female of the F₁ generation were counted to construct the age-stage, two-sex life table. The population dynamics of S. furcifera were predicted in 60 d by using Timing-MSChart software. 【Results】 The LC₅₀, L_C25 and LC₁₀ values of EMB against the 3rd instar nymphs of S. furcifera were 0.831, 0.222 and 0.068 mg/L, respectively, at 72 h after treatment. In the F₀ generation, S. furcifera female adults treated with EMB at the concentrations of LC₁₀, LC₂₅ and LC₅₀ had reduced average longevity by 7.19%, 24.81% and 34.21%, and decreased number of eggs laid per female by 22.24%, 31.22% and 41.53%, respectively, compared with the control group. EMB at the LC₂₅ concentration significantly prolonged the 5th instar female nymphal duration of the F₁ generation and EMB at the LC₅₀ concentration significantly prolonged the male adult longevity and total developmental duration of the F₁ generation compared with the control group. EMB at the LC₂₅ and LC₅₀ concentrations significantly prolonged the adult pre-oviposition period and total pre-oviposition period of the F₁ generation of S. furcifera, and significantly reduced the intrinsic rate of increase (r) and finite rate of increase (λ) of the F₁ generation compared with the control group. EMB at the LC₅₀ concentration significantly decreased the net reproductive rate (R₀) of the F1 generation and EMB at the LC₂₅ concentration significantly prolonged the mean generation time (T) of the F₁ generation compared with the control group. The three sublethal concentrations (LC₁₀, LC₂₅ and LC₅₀) of EMB significantly inhibited the population growth of S. furcifera. 【Conclusion】Sublethal concentrations of EMB have significant impacts on the longevity and fecundity of S. furcifera adults, and can decrease the population size of their offspring. The results of this study provide a theoretical basis for the field control of S. furcifera in agriculture.

【Aim】 The objective of this research is to clarify the resistance level and resistance stability of chlorantraniliprole in the rice leaffolder, Cnaphalocrocis medinalis, and to determine whether there are cross-resistance to other diamide insecticides in chlorantraniliprole-resistant populations. 【Methods】 The rice seedling dipping method was adopted to determine the resistance of 32 field populations of C. medinalis collected from nine provinces (autonomous regions) to chlorantraniliprole and tetraniliprole, the cross-resistance to other diamide insecticides in two chlorantranilipeole-resistant populations, and the resistance stability when the populations from Youxian, Hunan, Qianshan, Anhui, Lujiang, Anhui and Xing′an,Guangxi were not exposed to chlorantraniliprole in laboratory. 【Results】 The resistance of chlorantraniliprole in C. medinalis field populations kept increasing during 2019-2022. Lujiang, Xing′an, Wuxue, Danyang and Qianshan populations were monitored for the first time to have developed high level of resistance to chlorantraniliprole (102.3-135.1-fold), and other populations also reached moderate level of resistance (10.3-97.1-fold) in 2022. To tetraniliprole, all the monitored field populations kept susceptible during 2019-2021, while the populations monitored in 2022 have developed moderate level of resistance (41.9-98.0-fold). Moreover, the cross-resistance experiment results revealed that Jiaxing and Qianshan populations which appeared about 100-fold resistance to chlorantraniliprole also showed 31.6-100.5-fold cross-resistance to cyhalodiamide, tetraniliprole, cyantraniliprole, cyclaniliprole and tetrachlorantraniliprole. In addition, the chlorantraniliprole resistance of field populations decreased rapidly after 2-4 generations of successive rearing without exposure to insecticides in laboratory. 【Conclusion】 The field populations of C. medinalis have developed moderate to high level of resistance to chlorantraniliprole and tetraniliprole. Moderate to high level of cross-resistance to five other diamide insecticides was found in chlorantraniliprole-resistant populations. Besides, the resistance to chlorantraniliprole was unstable in C. medinalis field populations. So, we strongly suggested limiting or suspending the application of diamide insecticides in order to delay the resistance development and postpone the application of diamide insecticides in C. medinalis control in the future.

【Aim】 This study aims to reconstruct the phylogenetic relationships among the higher-level taxa (families and subfamilies) of Termitoidae using transcriptome and low-coverage whole-genome sequencing data, providing a phylogenomic approach for studing the systematic evolution of termites. 【Methods】 By downloading the existing transcriptome (70) and low-coverage whole-genome (5) sequencing data of 67 species of termites and 8 related species of Blattodea, we used BUSCO to evaluate these sequence data and screen the singlecopy nuclear genes. MAFFT was used to align the nucleotide and amino acid sequences of the obtained single-copy nuclear genes, and trimAl was used to trim the alignments. Phykit was used to generate nucleotide and amino acid sequence data supermatrices with different completeness (including 50% and 25% missing data, respectively) to investigate the effect of missing data on the phylogenetic reconstruction. IQ-TREE was used to construct the maximum likelihood (ML) trees based on each matrix. In addition, ASTRAL was utilized to summarize the ML trees constructed on each marker included in the amino acid dataset faa_all, and obtain the species tree. Finally, FcLM analysis implemented in IQ-TREE was used to test the topology structure of different trees and obtain support for possible phylogenetic relationships inferred from different datasets. 【Results】 A total of 1 325 single-copy nuclear genes from the existing transcriptome and low-coverage whole-genome sequencing data of termites were obtained. Based on these single-copy nuclear genes, we constructed genomescale supermatrices of nucleotide and amino acid sequence data, with nucleotide sequence datasets ranging from 144 294 to 1 839 525 sites and amino acid datasets ranging from 48 098 to 613 175 sites. Different types of data matrices generated similar phylogenetic relationships in Termitoidae and three nucleotide data matrices produced the same inter-family phylogenetic relationships. For the amino acid data, two out of the three concatenated gene datasets produced inter-family phylogenetic relationships that were largely consistent with the nucleotide sequence datasets. This study supports the monophyly of Termitoidae and suggests that Mastotermitidae is the sister group to all other termite families. In most analyses, Archotermopsidae and Stolotermitidae were sister groups, forming the 2nd diverging branch within Termitoidae. The family Kalotermitidae is also a relatively ancient lineage within the termites, positioned after the Archotermopsidae and Stolotermitidae. The family Kalotermitidae forms a sister group relationship with the Neoisoptera. All analyses strongly support the monophyly of Neoisoptera. Within Neoisoptera, the family Stylotermitidae is the sister group to the remaining termite lineages. The family Serritermitidae is also a relatively basal lineage within Neoisoptera. The family Rhinotermitidae is a non-monophyletic group. The family Termitidae is a monophyletic group, with four out of the six concatenated gene datasets and species trees supporting the subfamily Macrotermitinae as the sister group to all other subfamilies within Termitidae. Most analyses support the subfamily Apicotermitinae as the 2nd branch within Termitidae. The concatenated gene data matrix supports the non-monophyly of Termitinae, but the species tree recovered Termitinae as a monophyletic group. 【Conclusion】 This study demonstrates the utility of transcriptome and low-coverage whole-genome sequencing data in reconstructing the phylogenetic relationships within Termitoidae, yielding results consistent with the previous studies. However, further data sampling, including specimens and molecular markers, is needed to elucidate the inter-subfamily relationships within this insect group.

【Aim】To construct a yeast two-hybrid (Y2H) cDNA library of Musca domestica and investigate the proteins that could interact with the MD14-3-3. 【Methods】 Taking M. domestica as the research object, the mRNA was purified, the primary cDNA library was constructed, the secondary library was constructed by the recombinant pGADT7-DEST vector, so as to construct the Y2H. Then, the plasmid pGBKT7-MD14-3-3 were constructed as bait and used for screening the proteins interacting with MD14-3-3. Finally, the transformation and validation were verified. 【Results】 A Y2H cDNA library of M. domestica was successfully constructed, with the library storage capacity of 1.6×10⁷ CFU and the recombination rate of 100%. Two target proteins were obtained by Y2H screening. The results of transformation and validation showed that mucin-like protein HKR1 and antibacterial peptide ctenidin-1 interacted with MD14-3-3.【Conclusion】 Two proteins that interact with MD14-3-3 were identified from the successfully constructed Y2H cDNA library of M. domestica. Our results provide a basis for investigating the mechanism of immune response of M. domestica.

【Aim】 To clarify the molecular mechanism of 20-hydroxyecdysone (20E) in regulating the expression of the transcription factor gene BmFoxL2-2 of Bombyx mori, and analyze the expression pattern of SlFoxL2-2 in the testis of Spodoptera litura. 【Methods】 The 2 500 bp promoter sequence upstream of the initiation codon of BmFoxL2-2 was cloned from the testis genomic DNA of the 5th instar larva of B. mori by PCR and the potential cis-regulatory elements (CREs) were predicted by bioinformatics tools. pEGFP-BmBRC-Z1, pEGFP-BmBRC-Z2 and pEGFP-BmBRC-Z4 transcription factor expression plasmids and pGL3-BmFoxL2-2 plasmid were co-transfected into the BmN cells and the dual luciferase activity assay was performed to analyze the effects of BmBRCs on the promoter activity of BmFoxL2-2. The expression level of BmFoxL2-2 in the BmN cells at 4 h after treatment with 1 μmol/L 20E was determined by qRT-PCR, and the expression levels of BmBrc-z1 and BmBrc-z4 were detected as the control. The expression levels of BmBrc-z1 and BmBrc-z4 in the testis at different developmental stages (larva, prepupa, pupa and adult), and in the testis and ovary of the 5th instar larva and 3-day-old pupa of B. mori were determined by qRT-PCR. SlFoxL2-2 in the genome database of S. litura was identified by bioinformatics and the expression levels of SlFoxL2-2 in the testis and ovary of the 6th instar larva and adult, different tissues (fat body, midgut, haemolymph, head, cuticle and testis) of the 6th instar larva, the testis at different developmental stages, and in the testis, sperm and testis membrane of the 6th instar larva were determined by qRT-PCR. 【Results】 The about 2 500 bp promoter sequence upstream of the initiation codon of BmFoxL2-2 (Gene ID: 101735653) of B. mori was obtained, and 13 potential CREs of BRC were predicted. BmBRC-Z1 and BmBRC-Z4 significantly up-regulated the promoter activity of BmFoxL2-2, and the expression levels of BmFoxL2-2, BmBrc-z1 and BmBrc-z4 in the BmN cells at 4 h after treatment with 20E were also significantly up-regulated as compared with those of the control group. BmBrc-z1 and BmBrc-z4 were expressed in the testis of larva, prepupa, pupa and adult of B. mori. The expression levels of BmBrc-z1 and BmBrc-z4 in the testis of the 5th instar larva and 3-day-old pupa were significantly higher than those in the ovary. The expression level of SlFoxL2-2 of S. litura was high in the testis among different tissues, and was significantly higher in the testis and sperm than in the testis membrane of S. litura larvae, suggesting that SlFoxL2-2 also functions in the development of testis, especially in the spermatogenesis. 【Conclusion】 The expression of BmFoxL2-2 is regulated by BmBRC-Z1 and BmBRC-Z4 through 20E in B. mori, and the function of SlFoxL2-2 in the development of testis may be conserved in lepidopteran insects.

 【Aim】 Periplaneta americana commonly known as the American cockroach carries out a wide range of activities with the help of locomotor abilities using its femoral and thoracic muscles, reflecting ease of movement in various habitats and that it is able to utilize food substances by the help of metabolic activities for effective daily activities. Little is known about variations in the daily pattern of metabolic activities in P. americana. This study was conducted to investigate the circadian variation in metabolite contents and enzyme activities in the thoracic and femoral muscles of adult P. americana. 【Methods】 The study was carried out by collecting the femoral and thoracic muscles of the 8-day-old aduts of P. americana at 6:00, 12:00, 18:00 and 24:00 local time ［6:00, 12:00, 18:00 and 24:00 Greenwich mean time (GMT)］. The activities of four enzymes (amylase, lipase, proteinase and α-glucosidase) which are responsible for metabolizing or converting the food substances to utilizable substances during transport to the muscles and hydrolysis of the food substances necessary for fueling locomotion in insects, and the contents of the organic (glucose, protein and lipids) and inorganic ［sodium (Na ⁺), potasium (K ⁺), calcium (Ca ²⁺), chlorine (Cl ^-), iron (Fe ²⁺), magnesium (Mg ²⁺) and phosphate ion (PO ₃ ^-4)］ substances in these tissues were determined using standard biochemical analytical methods.【Results】 The activities of the four enzymes amylase, lipase, proteinase and α-glucosidase were detected in both femoral and thoracic muscles of P. americana adults throughout the 24 h but at varying activity levels at different time. The activities of amylase, lipase, proteinase and α-glucosidase tested in the femoral muscle followed this pattern: 12:00>6:00>24:00>18:00, and were higher in females than in males. In the thoracic muscle, the activities of amylase, lipase and proteinase at 6:00 and 12:00 were significantly higher than those at 18:00 and 24:00, and females had higher enzyme activities than males. In the thoracic muscles of adult males, the glucose content was significantly higher at 18:00 than at the other time points, and the protein contents at 18:00 and 24:00 were significantly higher than those at 6:00 and 12:00, and the lipid content was significantly higher at 24:00 than at the other time points, while in the thoracic muscles of adult females, the lipid content was significantly higher at 12:00 than at the other time points, the protein contents at 12:00 and 24:00 were significantly higher than those at 6:00 and 18:00, while the glucose content was significantly higher at 24:00 than at the other time points. In the femoral muscle, the lipid content was significantly higher at 18:00 than at the other time points. In the femoral muscle of adult males, the glucose content was significantly higher at 24:00 than at the other time points, and the protein content was significantly higher at 6:00 than at the other time points, while in the femoral muscle of adult females, the contents of glucose and protein were significantly higher at 24:00 than at the other time points. In the thoracic muscle of adult males, the Na ⁺ content was significantly higher at 18:00 than at the other time points, the contents of K ⁺ and Ca ²⁺ in males at 6:00 and 12:00 were significantly higher than those at 18:00 and 24:00, the Cl ^- content was significantly higher at 24:00 than at the other time points, the PO ₃ ^-4 contents at 6:00, 18:00 and 24:00 showed no significant difference, but were significantly higher than that at 12:00, while in the thoracic muscle of adult females, the Na ⁺ content was significantly higher at 6:00 than at the other time points, while the contents of K ⁺, Ca ²⁺ and Cl ^- were significantly higher at 12:00 than at the other time points, and the PO ₃ ^-4 contents at various time points were not significantly different. In the femoral muscle of the adult males, the contents of Na+ and Ca2+ were significantly higher at 12:00 than at the other time points, the K ⁺ content was significantly higher at 6:00 than at 18:00 and 24:00, while the contents of Cl ^-  and PO ₃ ^-4 were significantly higher at 6:00 than at the other time points, while in the femoral muscle of adult females, the contents of Na ⁺ and Cl ^- were significantly higher at 6:00 than at the other time points, the contents of K ⁺ and Ca ²⁺ at 6:00, 12:00 and 18:00 exhibited no significant difference, while were significantly higher than that at 24:00, and the PO ₃ ^-4 content exhibited no significant difference among various time points. 【Conclusion】 The results of this study suggest that P. americana adults possess the ability to metabolize their organic and inorganic substrates with the help of the enzymes amylase, lipase, proteinase and α-glucosidase for movement, during the peak time of activities.

【Aim】 To clarify the molecular characteristics and tissue expression properties of the biogenic amine receptor genes in Mythimna separata based on the adult brain transcriptome data of M. separata, so as to provide the basis for the functional research of the biogenic amine receptor genes of M. separata. 【Methods】 The biogenic amine receptor gene sequences were screened from the brain transcriptome database of adult M. separata. Gene mapping of the selected biogenic amine receptor genes was analyzed by mapping cDNA with the M. separata genome database. The phylogenetic analysis of the identified biogenic amine receptors was performed by using maximum likelihood method. The qRT-PCR was used to detect the expression levels of the identified biogenic amine receptor genes in the brain, antenna, labipalp, wing, leg, thorax and abdomen of female and male adults of M. separata.【Results】 A total of 17 biogenic amine receptor genes were identified from the transcriptome database of adult M. separata brain, including five dopamine receptor genes, five 5-hydroxytryptamine receptor genes, five octopamine receptor genes and two tyramine receptor genes. The 17 biogenic amine receptor genes were distributed on eight chromosomes, 7 of them were co-located on the chromosome 22. The identified biogenic amine receptors of M. separata had high homology with the biogenic amine receptors of Spodoptera litura, Bombyx mori and Manduca sexta. The dopamine receptor genes were highly expressed in the brain and antenna of female and male adults of M. separata, and the expression levels of MsepDop2, MsepDop3-1, MsepDop3-2 and MsepDopEcR were significantly higher in the female adult brain than those in the male adult brain. The octopamine receptor genes MsepOA1 and MsepOA2B2 were highly expressed in the thorax, and their expression levels in the thorax of female adults were significantly higher than those in the thorax of male adults. The expression levels of MsepOA3 and MsepOA2B1-3 were also higher in the olfactory tissues antenna and labipalp, with gender differences. The expression levels of tyramine receptor genes were high in the brain and antenna, and the expression level of MsepTA2 in the abdomen of female adults was significantly higher than that in the abdomen of male adults. The expression levels of Msep5-HT1 genes in the brain were significantly higher than those in the other tissues. The Msep5-HT2 genes had high expression levels in the brain, antenna, and labipalp.【Conclusion】 In this study, we obtained 17 biogenic amine receptor genes of M. separata, and clarified their expression profiles in different tissues of female and male adults of M. separata. Gender differences in the expression of some biogenic amine receptor genes in olfactory and reproductive tissues were revealed. This research provides a basis for further exploration on the physiological function of biogenic amine receptors in M. separata.

【Aim】 To assess the effects of temperature on the growth, development and reproduction of Xestia c-nigrum in Korla, Xinjiang, Northwest China, and to explore its adaptability to environmental temperature. 【Methods】 The egg hatching rates, larval survival rates, pupation rates, eclosion rates, developmental duration and fecundity of X. c-nigrum at 15, 20, 25, 30 and 35 ℃ were compared by using two-sex life table method, and the effects of different temperatures on the life table parameters of the population were analyzed. The developmental threshold temperatures and effective accumulated temperatures of X. c-nigrum at different developmental stages were also determined. During 2020-2022, the relationship between the population dynamics of X. c-nigrum by light-trapping and the daily average temperature change in Korla, Xinjiang was analyzed. 【Results】 At 15 ℃, the larval survival rate, pupation rate, and eclosion rate of X. c-nigrum were lower than 30%. At 30 ℃, the larval survival rate and pupation rate were lower than 10%, and the pupa could not normally emerge. At 35 ℃, the larvae could not survive. The duration of different developmental stages of X. c-nigrum shortened as the temperature rose, and the egg duration was 15.52, 7.40, 5.47, 4.88 and 3.88 d at 15, 20, 25, 30 and 35 ℃, respectively. The larval duration was 109.43, 40.53, 26.47 and 24.55 d at 15, 20, 25 and 30 ℃, respectively. The pupal duration was 41.43, 18.00 and 12.54 d at 15, 20 and 25 ℃, respectively. The pupal duration was 41.4, 18.0 and 12.5 d at 15, 20 and 25 ℃, respectively. The population showed negative growth at 15 ℃, and positive growth at 20 and 25 ℃, with the highest intrinsic rate of increase (r_m) at 25 ℃. The developmental threshold temperatures of egg, 1st-6th instar larvae and pupa were 9.81, 8.43, 9.95, 10.26, 12.52, 13.58, 12.60 and 10.81 ℃, respectively, and the effective accumulated temperatures were 79.62, 92.17, 56.09, 57.03, 39.35, 38.16, 80.72 and 172.39 degree.days, respectively. The monitored data from light.trapping during 2020-2022 showed that X. c.nigrum had three generations per year in Korla, Xinjiang, and the adult peak periods were in mid-May, late July and early September, with the average daily temperature range of 19.5-26.5 ℃. 【Conclusion】The population of X. c-nigrum shows negative growth when the temperature is lower than 15 ℃, and cannot complete its life cycle at over 30 ℃, moreover, 20-25 ℃ is more suitable for its growth and reproduction. This study provides a scientific basis for clarifying the temperature adaptability and its occurrence and dynamics of X. c-nigrum in Korla, Xinjiang.

【Aim】14-3-3 proteins are a class of regulatory proteins found in eukaryotic organisms, which can be involved in signal transduction, immune response, growth and development, and stress response. The aim of this study is to clone the full-length cDNA sequences of the 14-3-3 genes in Bemisia tabaci MED, and understand the characteristics of the proteins encoded by 14-3-3 genes and the spatiotemporal expression patterns of 14-3-3 genes. 【Methods】 The full-length cDNA sequences of 14-3-3 genes of B. tabaciMED were cloned by RT-PCR, and their biological properties were analyzed by bioinformatics software and online website. RTqPCR was used to determine the expression levels of 14-3-3 genes in different developmental stages (egg, 1st-4th instar nymphs and adult), in adult male and female, and in the head, thorax and abdomen of female adult of B. tabaci MED. 【Results】 Two subtypes of the 14-3-3 gene of B. tabaci MED were cloned and characterized: Bt14-3-3 epsilon(GenBank accession no.: XM_019046102.1) and Bt14-3-3 zeta(GenBank accession no.: XM_019057395.1). The open reading frames (ORFs) of Bt14-3-3 epsilon and Bt14-3-3 zeta were 771 and 744 bp, encoding 256 and 247 amino acids, respectively. The proteins encoded by Bt14-3-3 epsilon and Bt14-3-3 zeta were hydrophilic proteins without transmembrane helical region and signal peptide, and their secondary structure mainly consisted of α-helices. Phylogenetic tree analysis showed that Bt14-3-3 epsilon was clustered into one cluster with 14-3-3 epsilon proteins of Nilaparvata lugens, Cimex lectularius and Halyomorpha halys, sharing higher homology, while Bt14-3-3 zeta was more closely related to 14-3-3 zeta of N. lugens. RT-qPCR results showed that Bt14-3-3 epsilon and Bt14-3-3 zeta had higher expression levels in the egg, female adults and abdomen of female adults of B. tabaci MED. 【Conclusion】The full-length sequence, characteristics of the coded proteins and spatiotemporal expression of two subtypes of the 14-3-3 gene of B. tabaci MED have been clarified. The results of this study provide a basis for subsequent studies on the molecular function of 14-3-3 proteins.
Key words: Bemisia tabaci; gene cloning; 14-3-3 protein; bioinformatics; spatiotemporal expression

Insect wing polyphenism, as a typical example of the developmental plasticity of organisms, is the result of evolutionary adaptation to complex and variable environments. The brown planthopper (BPH), Nilaparvata lugens, is a representative model of insect wing polyphenism, and its nymphs have the option of developing into shortwinged or longwinged adults. The ability of developing into longwinged morphs enables BPHs to migrate over long distances, causing an infestation over a wide geographic rice planting area in Asia. Since the 1960s, there has been extensive research into the mechanisms behind wing polyphenism in BPHs, revealing that numerous environmental factors such as population density, host plant quality, temperature and photoperiod, and juvenile hormone can all influence the proportion of wing morphs. In the past 20 years, facilitated by the rapid development of biotechnologies in genomics, RNAi and gene editing, a breakthrough finding has been achieved in wing polyphenism of BPHs. FoxO has been identified as a switch gene for wing polyphenism in BPHs, where silencing or knocking out FoxO leads to the development of long-winged adults. Meanwhile, the insulin signaling pathway can inhibit FoxO from entering the nucleus by phosphorylating it, thus participating in wing polyphenism regulation. The zinc finger transcription factor Zfh1 can regulate the transcription of FoxO through promoter binding, paralleling the insulin signaling pathway in controlling wing polyphenism. Another zinc finger transcription factor, Rotund, can interact with FoxO to co-regulate wing polyphenism of BPHs. Additionally, the sex determination gene Transformer-2 and the c-Jun N-terminal kinase pathway can also influence wing polyphenism, indicating the presence of diverse molecular regulatory mechanisms for wing polyphenism in BPHs. Given the differences in the mechanisms of wing polyphenism among different suborders of Hemiptera, the elucidation of mechanisms in BPHs is far from fully explaining the mechanisms of wing polymorphism in Hemiptera or even the entire class of insects. However, these findings position themselves at the edge of wing polyphenism in insects and deepen our understanding of developmental plasticity and evolution of insect wings as well as other tissues.

-【Aim】 To sequence and analyze the complete mitochondrial genomes of Atractomorpha lata and Aularches miliaris, and to explore the phylogenetic relationships of Acridoidea at the mitochondrial genome level, especially the phylogenetic relationships between Pyrgomorphidae and Chrotogonidae.【Methods】 The mitochondrial genome sequences of A. lata and A. miliaris were determined on the Illumina HiSeq 2500 sequencing platform, and the mitochondrial genome structure, base composition, relative synonymous codon usage (RSCU) of protein-coding genes (PCGs) and tRNA secondary structure were analyzed. A gene sequence dataset of 13 PCGs+2 rRNA genes was constructed by using the mitochondrial genomes of 34 species known to Acridoidea as ingroups and those of two Eumastacoidea species as outgroups. The phylogenetic relationships of Acridoidea were constructed by maximum likelihood (ML) and Bayesian inference (BI) methods. 【Results】 The full-length mitochondrial genomes of A. lata and A. miliaris (GenBank accession numbers: OR544953 and OR253923, respectively) are 15 561 and 15 798 bp, respectively, both of which are closed circular molecules. The mitochondrial genomes of both A. lata and A. miliaris contain 37 genes (13 PCGs, 22 tRNA genes, 2 rRNA genes) and one control region, and KD gene rearrangement exists (trnK-trnD rearranges to form trnD-trnK). The A+T content of the mitochondrial genomes of A. lata and A. miliaris are 74.4% and 75.8%, respectively, showing obvious AT content bias. The gene arrangement, base composition, amino acid composition and RSCU of the mitochondrial genomes of A. lata and A. miliaris are similar to those of other species of Pyrgomorphidae and Chrotogonidae. All tRNA genes show the typical clover-leaf secondary structure except for the absence of DHU arm of trnS^AGN. The phylogenetic trees constructed by ML and BI methods had the same topological structure. Pamphagidae, Catantopidae, Oedipodidae, Arcypteridae, Gomphoceridae and Acrididae were clustered together, and the monophyly of Pamphagidae, Oedipodidae and Gomphoceridae was supported. The species of Pyrgomorphidae and Chrotogonidae clustered together in a clade and formed sister groups with other species of Acridoidea. The monophyly of Atractomorphinae of Pyrgomorphidae was supported, while the monophyly of Chrotogonidae was not supported due to the addition of Pyrgomorphidae species. 【Conclusion】 In this study, the mitochondrial genomes of A. lata and A. miliaris were determined and analyzed for the first time. At the mitochondrial genome level, the phylogenetic trees of Acridoidea were constructed, and the results indicated that the monophyly of Pyrgomorphida, Pamphagidae, Oedipodidae and Gomphoceridae was supported. Pyrgomorphidae and Chrotogonidae were closely related, forming a clade with species nested within each other, supporting the merging of Pyrgomorphidae and Chrotogonidae of the Chinese taxonomic system into one family.

【Aim】To sequence the complete mitochondrial genome of Gotra octocinctus, anlayze and explore the genome structure and phylogenetic relationship of Ichneumonoidea. 【Methods】 The complete mitochondrial genome of G. octocinctus was firstly sequenced on the Illumina NovaSeq platform, and then the general features and base composition of the mitochondrial genome were analyzed. Combined with the 47 mitochondrial genome sequences of Ichneumonoidea published in GenBank, the phylogenetic trees of Ichneumonoidea were constructed with two species in Chalcidoidea as outgroups based on the 13 proteincoding gene (PCG) sequences using Bayesian inference (BI) and maximum likelihood (ML) methods. 【Results】The fulllength mitochondrial genome of G. octocinctus is 16 003 bp (GenBank accession no.： OP850580.1), and consists of 22 tRNA genes, 13 PCGs, two rRNA genes and one control region (CR). The base composition of mitochondrial genome was clearly AT-biased and exhibited the negative AT-skew and GC-skew. There were four gene rearrangements, 13 overlapping regions (in total 85 bp) and 17 interspaced regions (in total 1 072 bp) in the mitochondrial genome of G. octocinctus. The phylogenetic tree based on 13 PCG sequences showed that Eucerotinae is a natural monophyletic group, the Aphidiinae and the “cyclostome” of Braconidae are sister group. 【Conclusion】 In this study, we sequenced and analyzed the complete mitochondrial genome of G. octocinctus, and found that the trnI-trnQ-trnM gene rearrangement events are common in the mitochondrial genome of Ichneumonidae, providing data for the further systematic research of mitogenomes of Ichneumonoidea.

【Aim】 (8E, 10E)-Dodecadien-1-ol (E8, E10-12∶OH) is the main component of sex pheromone in Cydia pomonella, and has a synergistic effect on the sex pheromone attractant to Grapholita molesta. The objective of this study is to detect the synergistic effect of E8, E10-12∶OH on the sex pheromone attractant to G. molesta, and identify the pheromone binding proteins (PBPs) and general odorant binding proteins (GOBPs) that primarily bind to E8, E10-12∶OH. 【Methods】 The electroantennogram (EAG) responses of male adults of G. molesta to 0.002, 0.02, 0.2, 2, 20, 200 and 2 000 μg of E8, E10-12∶OH were determined using EAG apparatus. The synergistic effect of E8, E10-12∶OH on the sex pheromone attractant to G. molesta was determined via field trapping trials. The values of inhibition constant Ki of the pheromone binding proteins GmolPBP1, GmolPBP2 and GmolPBP3, and the general odorant binding proteins GmolGOBP1, GmolGOBP2 and GmolGOBP3 of G. molesta binding to E8, E10-12∶OH were measured through fluorescence competitive binding assay. The key amino acids of GmolGOBP2 involved in E8, E10-12∶OH-binding were predicted by molecular dynamics simulation. The pivotal amino acid residues and weak interaction forces of GmolGOBP2 binding to E8, E10-12∶OH were validated via site-directed mutagenesis and fluorescence competitive binding assay. 【Results】 Male adults of G. molesta exhibited EAG response towards E8, E10-12∶OH, with the highest EAG response value of (0.57±0.14) mV to 2 000 μg E8, E10-12∶OH. E8, E10-12∶OH (200 μg) displayed a significant synergistic effect on the sex pheromone attractant to G. molesta, with the maximum synergistic multiplier of 2.46-fold. GmolGOBP2 had the strongest binding affinity to E8, E10-12∶OH ［Ki=(1.92±0.05) μmol/L］, and emerged as the main OBP binding to E8, E10-12∶OH. Molecular dynamics simulations showed that the amino acids Phe18, Ile100, Glu104, Val117 and Phe124 of GmolGOBP2 exhibited the lowest binding free energy when binding to E8, E10-12∶OH, being -1.18, -1.33, -3.34, -1.19 and -1.58 kj/kg, respectively. These amino acids were predicted as important residues for GmolGOBP2 to bind with E8, E10-12∶OH. Following site-directed mutagenesis of the above five residues to Ala, the GmolGOBP2 mutants E104A and F124A lost their binding affinities to E8, E10-12∶OH, indicating that Glu104 and Phe124 are the key amino acids for GmolGOBP2 to bind to E8, E10-12∶OH. 【Conclusion】 E8, E10-12∶OH emerges as an ideal synergist for developing efficient sex pheromone attractant for G. molesta. GmolGOBP2 plays an important role in perceiving interspecies pheromone E8, E10-12∶OH, with Glu104 and Phe124 identified as the key amino acid residues for GmolGOBP2 to bind to E8, E10-12∶OH.

【Aim】The apolipoprotein (apoLp) plays an important role in achieving the physiological functions in animals, but how it affects the growth and development of rice planthoppers remains unknown. Our study aims at investigating the role of apoLp in the feeding, survival and reproduction of Nilaparvata lugens. 【Methods】The full-length open reading frame (ORF) sequence of NlapoLp was obtained based on the genome from N. lugens, and its protein sequence was analyzed. The cluster analysis between NlapoLp and homologous sequences from other insect species was conducted using neighbor-joining method. The expression levels of NlapoLp in different developmental stages (egg, 1st-5th instar nymphs, and newly emerged short-winged female and male adults), and different tissues (head without salivary gland, salivary gland, midgut, fat body and ovary) of the short-winged female adults were analyzed using RT-qPCR. After RNAi by microinjection of dsNlapoLp into the 3rd instar nymphs of N. lugens, the expression level of NlapoLp was determined using RT-qPCR. Then the amount of honeydew secreted per female adult, nymphal survival rate and number of eggs laid per female adult of N. lugens on host rice were investigated after RNAi on insects at different developmental stages. 【Results】 Analysis of sequence features revealed that NlapoLp contains one signal peptide and five conserved domains, but has no transmembrane domain. The phylogenetic tree showed that the apoLp orthologs NlapoLp of N. lugens, LsapoLp of Laodelphax striatellus and SfapoLp of Sogatella furcifera shared the closest evolutionary relationships. Additionally, these orthologs also gathered with the apoLps of three other hemiopteran insects (Macrosteles quadrilineatus, Bemisia tabaci and Halyomorpha halys), indicating close relationships among them. RT-qPCR results showed that NlapoLp was expressed in N. lugens at various developmental stages and highly expressed in short-winged female adults. NlapoLp was highly expressed in the midgut, fat body and salivary gland of the short-winged female adults and lowly expressed in other tissues. Microinjection of dsNlapoLp into N. lugens significantly decreased the expression of NlapoLp. After RNAi, the amount of honeydew secreted per female adult, nymphal survival rate and number of eggs laid per female adult of N. lugens on host rice were significantly decreased as compared with those in the control group (dsGFP injection). 【Conclusion】 The apolipoprotein gene NlapoLp is expressed in various developmental stages and tissues of the short-winged female adults of N. lugens, and silencing NlapoLp via RNAi significantly affects the feeding, growth and development, and reproduction of N. lugens. These results lay the foundation for deeply exploring the mechanism of apolipoprotein in rice damage caused by insects, and provide key target for pest effective control.