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

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

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

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

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

【Aim】This study aims to investigate whether DNA methylation affects wing development of Bombyx mori through regulating autophagy. 【Methods】B. mori ovarian Bm12 cells and B. mori prepupae were treated with 5azadC, a DNA methylation inhibitor, at the doses of 1 and 2 μg, respectively, the number of Bm12 cells was observed under fluorescence microscopy, the methylation level in Bm12 cells was detected by dot blotting, the autophagy intensity was detected by lysosome staining, the expression levels of autophagyrelated protein (Atg) genes were detected by RT-qPCR, and the typing of the autophagy marker LC3 protein in Bm12 cells was detected by Western blotting and immunohistochemistry. Meanwhile, the wing phenotype of adult was observed, and the abnormal wing rate and wing area were calculated. After B. mori prepupae were treated with the autophagy activator SMER28 (2 μg), and using autophagy inhibitor Spautin-1 (2 μg) to rescue 5-aza-dC-treated prepupae, the autophagy intensity in the wing cells was detected by lysosome staining, the wing phenotype was observed, and the abnormal wing rate and wing area were calculated. 【Results】Treatment with 1 μg of 5-aza-dC inhibited the growth and decreased the methylation level of Bm12 cells, increased the autophagy level in Bm12 cells at 12, 24 and 48 h after treatment, and up-regulated the expression of Atg genes in Bm12 cells at 48 h after treatment. Injection of 2 μg of 5-aza-dC into B. mori prepupae increased the autophagy level, up-regulated the expression of Atg genes in adult wing cells, and resulted in a large proportion of deformed wings at 24, 48 and 72 h after treatment, with the increased abnormal wing rate (increased by 72.62%) and the decreased wing area (decreased by 66%) of adult. Injection of 2 μg of SMER28 into B. mori prepupae increased the autophagy level in the adult wing cells and resulted in a large proportion of deformed wings at 24, 48 and 72 h after treatment, with the increased abnormal wing rate (increased by 75.13%) and the decreased wing area (decreased by 48.79%) of adult. In addition, rescue experiment using Spautin-1 to rescue the 5-aza-dC-treated prepupae revealed that the autophagy inhibition could alleviate the effect of DNA demethylation on the adult wing development. 【Conclusion】The results of this study demonstrate that DNA methylation plays a role in the wing development of B. mori by regulating autophagy. Our results provide the experimental evidence for the regulation of DNA methylation on the insect development.

【Aim】 To explore the effect of piwi knock-down on hemocyte proliferation and differentiation in Drosophila melanogaster. 【Methods】 The D. melanogaster strains e33C-Gal4 and Hml-Gal4-UAS-2×EGFP were crossed with the wild strain w ¹¹¹⁸ and the strain UAS-piwi RNAi, respectively, to reduce the expression of piwi gene in circulating hemocytes or lymph glands of D. melanogaster. The localization of Piwi protein in hemocytes and its effect on hemocyte proliferation and differentiation in D. melanogaster were detected by immunofluorescence staining. 【Results】 Piwi protein was expressed in circulating hemocytes and the whole lymph glands of D. melanogaster, and was mainly localized in the cytoplasm. The knock-down of piwi gene resulted in significant increase in the number of circulating hemocytes and the number of cells in the M phase of mitosis, but the differentiation of plasmatocytes and lamellocytes in circulating hemocytes were not affected. The knock-down of piwi gene had no effect on the proliferation of lymph gland hemocytes, but resulted in the excessive differentiation of plasmatocytes and the generation of lamellocytes. 【Conclusion】 The knock-down of piwi gene in circulating hemocytes in Drosophila can induce the overproliferation of hemocytes, while the knockdown of piwi gene in lymph glands can induce abnormal differentiation of hemocytes.

The symbiotic relationship between endosymbionts and their insect hosts is ubiquitous in nature, and they are interdependent, interacting and coevolving. In recent years, studies on insect endosymbionts mainly focus on hemipteran and dipteran insects. However, a growing number of studies show that the interaction mode and mechanism between lepidopteran insects and their endosymbionts are also attracting more and more attention. Lepidopteran insects are widely distributed and play important roles in the ecosystem as herbivores and pollinators, and most of their larvae can cause great economic losses to the agricultural and forestry production. The diversity of endosymbiont community in lepidopteran insects is relatively low, which is mainly dominated by secondary symbiont Wolbachia. A few species are also infected with Spiroplasma, Arsenophonus and Rickettsia. These endosymbionts are mainly transmitted maternally from mother to offspring, whereas their horizontal transmission may also be occurring in nature. And they play important roles in the growth and development, reproductive manipulation, environmental adaptation and genetic evolution of hosts. Nowadays, diagnostic polymerase chain reaction (PCR), high-throughput amplicon sequencing, and metagenomic sequencing are generally used to detect endosymbionts. However, there are still some difficulties in the research of endosymbionts in lepidopteran insects, including that most endosymbionts can not be cultured in vitro, and the biological functions of endosymbionts with low abundance are difficult to be determined. Considering the distribution of endosymbionts and difficulties in lepidopteran insects, it is suggested that future research should focus on secondary symbionts and their biological functions.

【Aim】 Estrogen-related receptors (ERRs) belong to the nuclear receptor (NR) superfamily and play an important role in regulating metabolism and energy conversion in insects. Bisphenol A (BPA) is related to insect reproduction and neurological diseases. This study aims to explore the mechanism of BPA affecting Drosophila melanogaster ERR (dERR). 【Methods】 The docking of small molecule BPA with dERR protein constructed by Modeller 9.25 was simulated by AutoDock Vina, the molecular dynamics simulation was carried out using Gromacs 5.1.9, and the binding mode of BPA and dERR was explored in combination with the calculation of binding free energy. qRT-PCR method was used to detect the effects of exposure of BPA at three concentrations (0.1, 1 and 10 μg/L) for 6, 12 and 24 h on the transcription levels of dERR gene in adults and the 2nd instar larvae of D. melanogaster. 【Results】 Based on molecular docking and polar solvation energy, it is found that side chain amino acids such as Phe370 and Leu334 are the key amino acids for the binding of BPA to dERR. qRT-PCR analysis showed that the transcription levels of dERR gene in adults and the 2nd instar larvae of D. melanogaster changed significantly at 6 and 12 h after treatment with BPA of different concentrations, but those of 0.1 μg/L BPA treatment were almost equal to those of the control at 24 h. 【Conclusion】 BPA can affect the expression of dERR in D. melanogaster, and the mechanism may be related to the potential specific binding of BPA and dERR. 

Key words: Drosophila melanogaster; BPA; estrogenrelated receptor; molecular docking; molecular dynamics simulation; qRT-PCR

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

【Aim】 This study aims to identify the chemosensory protein (CSP) genes in the antennal transcriptome of the pea aphid, Acyrthosiphon pisum, and to investigate the binding characteristics of antennae-enriched CSPs of A. pisum with aphid alarm pheromones, sex pheromones and plant volatiles.【Methods】 Based on the antennal transcriptome data of A. pisum, the CSP genes in antennae were identified. The expression profiles of these CSP genes in antennae and different tissues (antennae, stylet, head without antenna and stylet, thorax, abdomen, leg and wing) of A. pisum adults were assayed based on RPKM value and by semiquantitative RT-PCR, respectively. The binding characteristics of these CSPs in antennae with aphid alarm pheromones and sex pheromones, and plant volatiles were assayed by fluorescence competitive binding assay.【Results】 A total of ten CSP genes were identified from the antennal transcriptome of A. pisum adults. The RPKM value and semiquantitative RT-PCR results revealed that ApisCSP2, ApisCSP4 and ApisCSP5 were highly expressed in the antennae of A. pisum adults. The fluorescence competitive binding assays indicated that ApisCSP4 showed strong binding affinities to the main component of aphid alarm pheromone ( E)-β-farnesene (EβF), and the minor component (-)-α-pinene, with the K _i values of 2.2±0.8 and 4.9±0.7 μmol/L, respectively. ApisCSP5 exhibited strong binding affinities to the two components of sex pheromones (+)-(4a S, 7 S, 7a R)-nepetalactone and (-)-(1 R,4a S,7 S,7a R)-nepetalactol, with the K _i values of 4.8±0.9 and 2.6±0.6 μmol/L, respectively.【Conclusion】 There are ten CSP genes identified in the antennal transcriptome of A. pisum adults, among which ApisCSP4 and ApisCSP5 may be involved in the transport of aphid alarm pheromones and sex pheromones, respectively.

【Aim】 To explore the feasibility of deep learning in automatic recognition counting of Spodoptera frugiperda adults, and to evaluate the recognition counting precision of the model, so as to provide image recognition and counting methods for intelligent pest monitoring by machine. 【Methods】 A self-designed pest image monitoring device based on sexual attraction was used to automatically and regularly collect images of trapped S. frugiperda adults. Combined with the collection of images of S. frugiperda adults on sticky coloured cards with ship-shape trap, a dataset was constructed. The YOLOv5 deep learning object detection model was used for feature learning. The models of Yolov5s-A1, Yolov5s-A2, Yolov5s-AB and Yolov5s-ABC were obtained by model training using different image datasets, including the original images of S. frugiperda adults, S. frugiperda adult images with edge incomplete objects removed, S. frugiperda adult images with similar detection objects (S. litura adults) added, and negative samples without detection objects. The detection results of test samples under different occlusion gradients using different models were compared. Precision (P), recall (R), F1-measure, average precision (AP), and counting accuracy (CA) were used to evaluate these models. 【Results】 The recognition precision, recall and F1-measure of Yolov5s-A1 trained by the original image set reached 87.37%, 90.24% and 88.78, respectively. The model Yolov5s-A2 trained by images with edge incomplete objects removed had a recognition precision of 93.15%, a recall of 84.77%, and F1-measure of 88.76. The recognition precision, recall and F1-measure of Yolov5s-AB trained by images of added S. litura adult samples reached 96.23%, 91.85% and 93.99, respectively. The model Yolov5s-ABC trained by negative samples without detection objects had a recognition precision of 94.76%, a recall of 88.23%, and F1-measure of 91.38. The order of average precision of four models from high to low was as follows: Yolov5s-AB>Yolov5s-ABC>Yolov5s-A2>Yolov5s-A1; and the result of Yolov5s-AB was similar to that of Yolov5s-ABC. The order of counting accuracy of four models from high to low was as follows: Yolov5s-AB>Yolov5s-ABC>Yolov5s-A2>Yolov5s-A1. 【Conclusion】 The results show that the method developed in this study is applicable for the recognition and counting of S. frugiperda adults on pest image monitoring equipment and the sticky coloured card with trap under control conditions, and the deep learning technology is effective for the identification and counting of S. frugiperda adults. The automatic recognition and counting method for S. frugiperda adults based on deep learning has good robustness to insect body posture changes, sundries interference, etc. It can automatically count the number of S. frugiperda adults with various body postures and damaged body. The method has a broad application prospect in pest population monitoring.

【Aim】 This study aims to identify microRNA (miRNA) and possible target genes involved in the gonadal development of Bombyx mori through miRNA microarray and transcriptome analyses of the testis and ovary of the 5th instar larvae of B. mori. 【Methods】 A new generation of highthroughput sequencing platform was used to perform miRNA microarray analysis and transcriptome sequencing of the testis and ovary (defined as test and control, respectively) of the 5th instar larvae of B. mori. According to the criteria of P<0.05 and log ₂(fold change, FC)≥2, the differentially expressed miRNAs of test vs control were screened. According to the criteria of q≤0.05 and ［log ₂ (fold change)］≥1, the differentially expressed genes (DEGs) of test vs control were screened by comparative analysis. Eight up-regulated and 12 down-regulated differentially expressed miRNAs were randomly selected,and their expression and their predicted five target genes were verified by qRT-PCR. The DEGs and target genes of the differentially expressed miRNAs were enriched by KEGG pathway analysis. 【Results】 Sixty-eight differentially expressed miRNAs and 3 991 DEGs were identified from the testis and ovary (test vs control). Among them, 36 and 32 miRNAs were up-regulated and down-regulated, respectively, and 2 033 and 1 958 DEGs were up-regulated and down-regulated, respectively. qRT-PCR verification results of differentially expressed miRNAs were consistent with the microarray data. KEGG pathway enrichment analysis showed that the DEGs were significantly enriched in the signal pathways involved in metabolism and ribosome. The possible target genes of differentially expressed miRNAs in the DEGs were predicted. Four groups of miRNAs and their target genes showing the opposite expression trend were found, including bmo-miR-2774a and LOC101745556, bmo-miR-92b and LOC101735954, bmo-miR-3266 and LOC733130 and LOC778467, respectively. One group of miRNA and its target gene showing the consistent expression trend was bmo-miR-3321 and LOC101744895. The results of qRT-PCR of five target genes were consistent with the results of transcriptome sequencing. 【Conclusion】 In this study, the transcriptome and miRNA microarray data of the testis and ovary of the 5th instar larvae of B. mori have been obtained, and four groups of miRNAs and their target genes showing the opposite expression trend and one group of miRNA and its target gene showing the consistent expression trend screened and verified, laying a foundation for exploring the development differences between the testis and ovary of B. mori.

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

Insect oral secretion (OS), also known as vomit, is a mixture of saliva secreted by salivary glands and secretions secreted by guts in insects. During insect feeding on host plants, OS is secreted into plants and affects plant defense responses. RNA interference (RNAi) is a valuable reverse genetics tool to study insect gene function and also a new technology to be used in pest control. In this article, we mainly reviewed the effects of insect OS on host plant defense, the identification of insect OS effectors and the feasibility and application of OS effectors based on RNAi technology in pest control. Insect OS affects host plant defense mainly by interfering with jasmonic acid signalingpathway, sieve tube obstruction, and  Ca²⁺ pathway and other defense responses in host plants, and then promotes insects to ingest food. At present, the main methods of identification of insect OS effectors are based on the transcriptomic analysis of insect salivary glands and proteomic analysis of OS. Most of the OS effectors have been identified from insects with sucking mouthparts, and less reported in insects with chewing mouthparts. The functional studies revealed that the expression of insect OS effectors in host plants can affect the survival rate, fecundity, and feeding ability of insects and other important physiological indexes of both insects and plants. By identifying the interaction between OS effectors and plant defense mechanisms, the roles of OS effectors in the relationship between insects and host plants have been further demonstrated. Based on RNAi technology, the expression levels of OS effector genes are downregulated, and the growth and development are affected in many insects by microinjection-, feeding-, and plant-mediated RNAi using OS effector genes as targets, suggesting that OS effector genes could be used as RNAi targets. Although the studies are still in the laboratory stage, their application in pest control has been proven to be feasible in certain degree. Insect oral secretions are a new direction to study the interaction mechanism between insects and host plants. Finally, the future research directions of OS have been prospected, hoping toprovide some theoretical guidance for studies of pest control in China.

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

【Aim】 Insects perceive external nutritional status, and nutritional signals in vivo are transmitted through many signal pathways to regulate insect growth and reproduction. This study aims to tentatively explore the molecular mechanism of nutritional regulation on the growth and reproduction of the rice brown planthopper, Nilaparvata lugens. 【Methods】 The day-2 3rd instar nymphs of N. lugens were fed to adults under different nutrient conditions ［fed with 100% artificial diet (pure artificial diet D-97, the control), 50% artificial diet and 25% artificial diet, respectively］, and the body weight, developmental duration, survival rate and number of mature eggs per ovary were counted. Then, the relative expression levels of IIS, TOR and AMPK signaling pathway related genes (InR1, InR2, AKT, FoxO, TOR, S6K, 4EBP, AMPKα, AMPKβ and AMPKγ) in different tissues (ovary, body fat and other tissues) of the 2-day-old adults were detected by quantitative PCR, and the phosphorylation levels of Akt, FoxO and AMPK in the ovary and other tissues of the 6-day-old adults were detected by Western blot. Meanwhile, the ROS levels in different tissues of the 6-day-old adults and the titers of juvenile hormone (JH) and 20-hydroxyecdysone (20E) in N. lugens at different developmental stages were also detected. 【Results】 Compared with the control fed with 100% artificial diet, the artificial diet of lower concentrations resulted in a significant decrease in body weight from the day-2 5th instar nymph to adult, shortened developmental duration from day-2 3rd instar nymphs to adult, an increased mortality, and a significant decrease in the number of mature eggs per ovary of N. lugens. The expression levels of IIS, TOR and AMPK signaling pathway related genes InR2, TOR, 4EBP and AMPKα in the ovary, body fat and other tissues, AKT, S6K and AMPKγ in the fat body and other tissues, and InR1, FoxO and AMPKβ in the other tissues of the 2-day-old adults fed with the artificial diet of lower concentrations decreased significantly as compared to those in the control, while those of InR1, AKT, FoxO, and AMPKγ  in the ovary were relatively stable. The phosphorylation levels of AKT, FoxO, and AMPK in the ovary and other tissues of the 6-day-old adults fed with the artificial diet of lower concentrations were significantly increased as compared with those of the control. With the decrease of nutrient concentration in the artificial diet, the ROS levels in different tissues of the 6-day-old adults increased significantly as compared to that in the control. The JH titers in the day-2 4th instar nymphs under different nutrient conditions showed no significant difference, while the JH titers in the day-2 5th instar nymphs and 2-day-old adults under low nutrient conditions were significantly decreased and increased, respectively, as compared to those in the control. Low nutrient conditions resulted in a significant increase in 20E titer both in nymphs and adults. 【Conclusion】 Under conditions of nutrient deficiency, the expression levels of key genes in the nutritional signal transduction pathways including IIS, TOR and APMK pathways in N. lugens decrease, while the ROS level significantly increases, and the biosynthesis of JH and 20E is affected by regulating the phosphorylation levels of AKT, FoxO and AMPK.

As an important part of insects, nocturnal species have evolved some sensory mechanisms adapted to their habitats. It is generally believed that nocturnal insects mainly rely on olfaction and mechanical perception to explore habitats, and the visual system has been degraded or lost. In recent years, with the application of new biological technologies such as infrared night vision, electroretinogram (ERG) and optic nerve, breakthroughs have been made in visual and ecological research of insects. Since 2002, it has been successively found that some nocturnal insects such as moths, bees and dung beetles had evolved a remarkable capacity of dimlight vision, and can see brightness, color, shape, size, contrast, polarized light and motion at night (light intensity lower than 0.3 lx) as in bright day, showing an immense potential for visually regulating behaviors in nocturnal insects. In addition, the pupil, focal length, rod and pigment particles of compound eyes of these nocturnal insects have evolved some morphological and physiological characteristics to improve the optical sensitivity and to adapt to the dim-light environment at night. Since the study of dim-light vision and the mechanisms of visual adaptation in nocturnal insects is still in its infancy with a focus on flower-visiting or fecal-feeding insects, the research of the following aspects should be streagthened: (1) the dim-light vision in major nocturnal agricultural pests; (2) the optical structure characteristics of atypical superposition compound eye and the mechanisms of its adaptation to dim-light environment; (3) the mechanisms of visual adaptation in nocturnal insects in response to dim-light environment; and (4) the development of new pest control technology based on dim-light vision in nocturnal insects.

【Aim】 This study aims to establish the transcriptome database of diapause eggs of Galeruca daurica, to reveal the genes and metabolic/signaling pathways related to egg diapause, and to explore the molecular mechanism of egg diapause at the transcriptomic level. 【Methods】 The Illumina NovaSeq 6000 platform was used to perform transcriptome sequencing and bioinformatics analysis of the diapause and diapause-terminated eggs of G. daurica. The DESeq software was applied to analyze the differentially expressed genes (DEGs) between the diapause and diapause-terminated eggs, and the DEGs were subjected to the KEGG pathway enrichment analysis. The expression profiles of 10 randomly selected DEGs were verified by qRT-PCR. 【Results】 According to the transcriptome sequencing results from the diapause and diapause-terminated eggs of G. daurica, a total of 53 389 unigenes including 2 145 DEGs were obtained, of which 24 DEGs are related to juvenile hormone signaling and fatty acid biosynthesis and degradation. Compared with those in the diapause-terminated eggs, 1 297 DEGs in the transcriptome of diapause eggs were up-regulated and enriched in 124 KEGG pathways, among which ribosome pathway was significantly enriched, and 848 DEGs were down-regulated and enriched in 73 KEGG pathways, among which MAPK signaling pathway and glycosaminoglycan biosynthesis were significantly enriched. The qRT-PCR analysis showed that the expression profiles of the 10 randomly selected DEGs were completely consistent with the RNA-Seq results based on the transcriptome data. 【Conclusion】 Pathways of juvenile hormone, fatty acid biosynthesis and degradation, ribosome, MAPK signaling and glycosaminoglycan biosynthesis may play important roles in the regulation of egg diapause in G. daurica.

【Aim】 Spinetoram is one of the candidate pesticides most used for controlling the western flower thrips, Frankliniella occidentalis, on vegetables. This study aims to assess the effects of multigeneration spinetoram stress on F. occidentalis. 【Methods】 The 2nd instar nymphs of F. occidentalis were screened for six generations with LC₂₅ dosage of spinetoram by the leaf dipping method, and the insecticide sensitivity and detoxification enzyme activities in the nymphs were determined. The agestage twosex life table was used to analyze the effect of LC₂₅ dosage of spinetoram on the life table parameters of F. occidentalis offspring (F₇). 【Results】 After the 2nd instar nymphs of F. occidentalis were selected with LC₂₅ dosage of spinetoram for six generations, the resistance ratio increased to 6.4 folds as high as that of the control treated with water. CarE and GSTs in the day-2 2nd instar nymphs of F₆ generation were significantly activated, with their activities 1.26 and 1.21 folds as high as those of the control, while MFOs and P450s were significantly inhibited, with their activities only 54.00% and 51.78% of those of the control, respectively. When the 2nd instar nymphs of F. occidentalis were selected with LC₂₅ dosage of spinetoram for six generations, the longevity (19.33 d) and fecundity (69.80 eggs) of female adult significantly decreased as compared to those of the control (21.60 d and 83.17 eggs, respectively), the female adult longevity (16.82 d) and male adult longevity (8.29 d) of F₇ generation were also significantly shortened as compared to those of the control (20.28 d and 10.86 d, respectively), the fecundity of F₇ generation (59.23 eggs laid per female) extremely significantly decreased as compared to that of the control (76.96 eggs laid per female), but the female to male sex ratio (2.28) significantly increased as compared to that of the control (1.03). The net reproductive rate (R₀), intrinsic rate of increase (r) and finite rate of increase (λ) in F₇ generation of F. occidentalis after selection with LC₂₅ dosage of spinetoram for six generations had no significant change. 【Conclusion】 The resistance of F. occidentalis to spinetoram

increases slowly within six generations under selection by LC₂₅ dosage of spinetoram. Spinetoram stress not only causes significant changes in the detoxification enzyme ctivities in F. occidentalis, but also inhibits its development and reproduction.

【Aim】 This study aims to establish the relative susceptible baselines of the fall armyworm, Spodoptera frugiperda, to commonly used insecticides in order to provide basic data for systematically monitoring the resistance of S. frugiperda to insecticides in China. 【Methods】 S. frugiperda individuals were collected from corn fields and bred in the laboratory without exposure to any insecticides for 5-7 generations. The susceptibility of the 3rd instar larvae of S. frugiperda to seven commonly used insecticides (emamectin benzoate, spinetoram, chlorfenapyr, indoxacarb, tetrachlorantraniliprole, lufenuron and chlorantraniliprole) belonging to six pesticide categories was determined by leaf-dip method and topical application, and that of the 2nd instar larvae of S. frugiperda to these seven insecticides was determined by diet surface overlay method. Based on the bioassay results, the relative susceptible baselines of S. frugiperda to these seven insecticides were established. 【Results】 The LC₅₀ or LD₅₀ values of the above seven insecticides to S. frugiperda larvae were 0.054-12.131 mg/L by leaf-dip method, 0.355-4.707 μg/g by topical application (excluding lufenuron), and 0.003-0.238 μg/cm² by diet surface overlay bioassay, respectively. 【Conclusion】 The relative susceptible baselines of S. frugiperda larvae to the commonly used insecticides have been established using three different bioassay methods, providing basic data for the resistance monitoring and chemical control of S. frugiperda in China.

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

【Aim】 The aim of this study is to clarify the phylogenetic status of the tribe Sinosenini in Cicadoidea, in which the cicadas have no timbal organs. 【Methods】 Based on adult specimens of Karenia caelatata of Sinosenini collected in Ningshan, Shaanxi, northwestern China, the mitochondrial genome of K. caelatata was sequenced, annotated, bioinformatically analyzed, and compared with the mitochondrial genomes of other taxa of Cicadoidea. Molecular phylogenetic trees for Cicadoidea were constructed using both maximum likelihood (ML) method and Bayesian inference (BI) method. 【Results】 The mitochondrial genome of K. caelatata (GenBank accession number: MN922304) is 14 960 bp in length, and the gene organization, nucleotide composition and codon usage of proteincoding genes display similar structural characteristics to those of other taxa of Cicadoidea. Analysis of nucleotide diversity reveals that genes atp8, nad6 and nad2 are highly variable, while cox1 is more conserved. Ratios of nonsynonymous and synonymous substitution rates indicate that the evolution of mitochondrial genomes in Cicadoidea is under a highlevel purifying selection. Results of phylogenetic analyses support the monophyly of Cicadomorpha, revealing the relationship of the three superfamilies of this infraorder as (Membraciodea+(Cicadoidea+Cercopodidea)). Karenia is clustered with representatives of the tribe Dundubiini in the subfamily Cicadinae and most closely related to the genus Meimuna. Mogannia and Vagitanus, representatives of Cicadatrini, are clustered with the members of Cicadettinae. Yezoterpnosia is not a monophyletic group. 【Conclusion】 Sinosenini should be transferred from Cicadettinae to Cicadinae and merged with Dundubiini, while Cicadatrini should be transferred from Cicadinae to Cicadettinae. Our results provide new information for future study of evolution of cicadas with different sound-producing mechanisms.

【Aim】Hemocyte plays a leading role in insect hemolymph immunity. Analyzing the changes of hemocyte density of the silkworm, Bombyx mori larvae and their causes, and the relationship between hemocyte density and B. mori resistance, is an important part of hemocyte immune regulation and resistance breeding of silkworm.【Methods】Hemocyte density (hemocyte number) in 10 μL hemolymph of the silkworm variety Dazao at different instars (the day-1-4 4th instar, the day-1-8 5th instar and the wandering larval stage) was evaluated by a hemocytometer. The cross-sectional image area was estimated by ImageJ software to represent the relative size of hematopoietic organs. The numbers of hemocytes in the hemolymph of the day-1 5th instar larvae of different silkworm varieties including Jingsong, Haoyue, Liangguang 2, 932, Furong, 7532 and Xianghui were measured by a hemocytometer. The relative expression levels of hematopoietic regulation factor genes BmBCFI, BmUsh, BmGATA and BmLz in the hemolymph of the day-1 5th instar larvae of Haoyue and Liangguang 2 were detected by qRT-PCR. After the day-1 and -3 5th instar larvae of Dazao were infected by Escherichia coli for different time, the hemocyte numbers in the hemolymph were measured by a hemocytometer and the relative expression levels of the above hematopoietic regulation factor genes in the hemolymph were detected by qRT-PCR. After RNAi of BmBCFI, BmUsh and BmLz for different time, the relative expression levels of target genes in the hemolymph of the 5th instar larvae of Dazao were detected by qRT-PCR. At 6 h after the 5th instar larvae of Dazao were infected by E. coli following RNAi of BmBCFI, BmUsh and BmLz for 48 h, the relative expression levels of target genes and immune-related genes BmRelish, BmCactus, BmSpzl and BmPGRP-LE in the hemolymph were detected by qRT-PCR, and the numbers of different types of hemocytes in the hemolymph were counted by a hemocytometer. The correlations between the hemocyte number and viability of the 5th instar larvae at high temperature of 35℃ were analyzed for 12 practical silkworm varieties.【Results】The hemocyte numbers of Dazao gradually increased during the 4th instar larval stage, reached a peak at the day-1 5th instar larval stage, began to decrease at the day-2 5th instar larval stage, and then slightly increased during the wandering stage. The hematopoietic organs gradually grew during the early and middle 5th instar larval stages, reached a peak at the day-6 5th instar larval stage, then diminished significantly and finally disintegrated. The time and trend of changes in the size of hematopoietic organs were not consistent with those of the changes of the hemocyte numbers. The expression levels of hematopoietic regulation factor genes BmBCFI, BmUsh and BmLz in Liangguang 2 with higher hemocyte numbers were higher than those in Haoyue with lower hemocyte numbers. After the 5th instar larvae of Dazao were infected by E. coli, the expression levels of BmBCFI, BmUsh and BmLz were significantly up-regulated when hemocyte numbers reached a peak. The oenocytoid numbers significantly reduced after down-regulating BmLz or BmUsh via E. coli infection following RNAi, and the plasmatocyte number and the number of total hemocytes significantly decreased after down-regulating BmBCFI via E. coli infection following RNAi. The expression levels of BmRelish in the Imd pathway and BmCactus in the Toll pathway were both significantly down-regulated after down-regulating BmBCFI or BmUsh via E. coli infection following RNAi, implying that BmBCFI and BmUsh are related to the activation of NF-κB signaling pathway and the formation of immune factors such as antimicrobial peptides. The hemocyte numbers varied greatly among different silkworm varieties, and the summer-autumn varieties tended to have higher hemocyte numbers than spring varieties. There was a negative correlation between the hemocyte number and the death index of the 5th instar larvae of silkworm reared at high temperature of 35℃.【Conclusion】Expression level of hematopoietic regulation factor genes of B. mori can affect the hemocyte density. BmUsh and BmLz influence the oenocytoid density of B. mori, and BmBCFI is associated with the plasmatocyte formation. Moreover, BmBCFI and BmUsh are likely to be related to the activation of NF-κB signaling pathway in B. mori. The hemocyte density is positively correlated with the viability of B. mori larvae fed at high temperature.

【Aim】 This study aims to clone SfTPS gene from the fall armyworm, Spodoptera frugiperda, and to analyze its relative expression levels in different developmental stages, different tissues and the 5th instar larvae under different temperature stresses, so as to lay the foundation for further exploring the function of TPS in the growth and development of S. frugiperda and its anti-stress response. 【Methods】 The full-length coding region of S. frugiperda SfTPS was cloned by RT-PCR technology and analyzed by bioinformatics. The relative expression levels of SfTPS in different developmental stages (egg, 1st-6th instar larva, pupa, and adult), different tissues of the 5th instar larva (integument, midgut, and fat body), and the 5th instar larvae of S. frugiperda subjected to short-term (2, 4 and 8 h) high temperature (35℃) and low temperature (10℃) stress were detected by RT-qPCR technology. 【Results】 The cDNA sequence of TPS gene of 2 571 bp was cloned from S. frugiperda and named SfTPS (GenBank accession number: MT920672). Its open reading frame (ORF) is 2 481 bp in length, encoding 826 amino acids with two conserved domains (TPS and TPP). Homologous comparison and phylogenetic analysis showed that TPS proteins in insects are highly conservative. SfTPS has the closest relationship with TPS of S. litura, showing 99.15% amino acid sequence identity. The proportions of α-helix, β-sheet and random coil in SfTPS are 38.14%, 12.23%, and 48.55%, respectively. The tertiary structure of SfTPS is homo-dimer. The RT-qPCR results showed that SfTPS was lowly expressed in the egg and 1st-5th instar larval stages of S. frugiperda, and highly expressed in the 6th instar larval, pupal and adult stages. Moreover, the relative expression level of SfTPS changed greatly before and after the metamorphosis of S. frugiperda. The tissue distribution results showed that SfTPS had the highest expression level in the fat body of the 5th instar larvae of S. frugiperda. After the 5th instar larvae of S. frugiperda were subjected to low temperature (10℃) and high temperature (35℃) stress for 2-8 h, the relative expression levels of SfTPS were significantly higher than that of the control (25℃), being 4.43-9.34- and 2.50-6.03-fold as high as that of the control, respectively. 【Conclusion】 SfTPS gene might play important roles in the growth and development, and resisting high and low temperature stress in S. frugiperda.

【Aim】 Mycterothrips gongshanensis is a new outbreak thrips pest on tea ( Camellia sinensis) plants in Yunnan, southwestern China. This study aims to clarify the biological and ecological characteristics of M. gongshanensis, to ascertain its development, survival and reproduction, and to simulate its population growth. 【Methods】 The age-stage two-sex life table of the experimental population of M. gongshanensis originated from Lincang, Yunnan, southwestern China was established, and the life history, survival rate, fecundity and other life table parameters of the experimental population of M. gongshanensis feeding on young tea leaves at 25℃ were observed and analyzed. Finally, its population growth for a period of 60 d was simulated. 【Results】 The developmental duration of M. gongshanensis at the egg, 1st instar nymphal, 2nd instar nymphal, prepupal and pupal stages was 3.89±0.04, 1.71±0.04, 3.14±0.03, 2.23±0.04 and 3.32±0.05 d, respectively. The average longevity of female adult was 15.50±0.32 d, while that of male adult was 14.06±0.26 d. The mean number of eggs laid per female was 36.12±0.78. The survival rate of the preadult stage was high, and the mortality sharply increased after the 25 day-old adult stage. The intrinsic rate of increase ( r), finite rate of increase ( λ), mean generation time ( T), and net reproductive rate ( R ₀) of the experimental population of M. gongshanensis were 0.1379±0.0044/d, 1.1479±0.0050/d, 21.33±0.13 d, and 18.95±1.68, respectively. Starting with 10 eggs, the population of M. gongshanensis reared in the absence of external interference will multiply to 17 335 individuals in 60 d based on computer simulation. 【Conclusion】 The population of M. gongshanensis in Lincang, Yunnan has high survival rate, high fecundity, and short mean generation time, and consequently, the population can grow very fast in this area.

【Aim】 To screen the high efficient delivery nanocarrier of dsRNA used for RNAi in Laodelphax striatellus. 【Methods】 Chitosan, carbon quantum dot (CQD), and lipofectamine 2000 were used as representative nanoparticles (NPs). The dsRNA loading efficacy of each NP was measured by spectrophotometry. The membrane-bound trehalase gene of L. striatellus, LsStre, was selected as the target gene to test the RNAi efficiency mediated by the three NPs. The mRNA expression levels of LsStre in the 2nd instar nymphs of L. striatellus at 2 d after being fed with dsLsStre mediated by different NPs were quantified by using real-time quantitative PCR (qPCR) strategy, and the corrected mortality rates induced by dsRNAs in 6 d were also detected and calculated. The synergic effects of the three NPs to RNAi of LsStre were evaluated based on the corrected mortality rates of the 2nd instar nymphs after RNAi with dsLsStre mediated by different NPs compared with that caused by naked dsLsStre (the control). 【Results】 All the three NPs could load dsEgfp, with the loading efficiencies of the three NPs coupled with dsEgfp all over 95%. All the three NPs showed low toxicity to the 2nd instar nymphs of L. striatellus. The qPCR results demonstrated that compared to the control group fed with naked dsLsStre not encapsulated with nanoparticles (causing 46% inhibition rate on the expression level of LsStre), chitosan and CQD significantly increased the RNAi efficiency of LsStre via feeding delivery, causing 78% and 84% inhibition rate, respectively, on the expression level of

LsStre, but lipofectamine 2000 could not significantly enhance the RNAi efficiency of LsStre, causing 52% inhibition rate on the expression level of LsStre. Moreover, the feeding assays also showed that chitosan and CQD significantly improved the dsLsStre-mediated lethal effect on the 2nd instar nymphs of L. striatellus. At 6 d after being fed with chitosan and CQD NP-dsLsStre conjugates, the corrected mortality of the 2nd instar nymphs of L. striatellus reached 76% and 82%, respectively, and the synergism ratios (SRs) of chitosan-and CQD-mediated RNAi groups were 2.17 and 2.34, respectively, compared with the control fed with naked dsLsStre (causing 35% corrected mortality). Meanwhile, lipofectamine 2000 was the most inefficient carrier for inducing RNAi in L. striatellus (SR=1.09), and lipofectamine 2000-dsLsStre conjugates caused 38% mortality of the 2nd instar nymphs of L. striatellus. 【Conclusion】 Chitosan and CQD nanocarriers are

more efficient to deliver dsRNA than lipofectamine 2000 in L. striatellus. The results are helpful in elucidating the RNAi efficacy boosted by NPs and provide a theoretical basis and practical strategies for developing and screening novel nanocarriers to realize the eco-friendly pest control.

【Aim】To explore the role of 3-hydroxy-3-methylglutaryl coenzyme A reductase gene (HMGR), a key gene of juvenile hormone (JH) biosynthesis, in the reproduction of the white-backed planthopper, Sogatella furcifera.【Methods】Based on the published genome and transcriptome data of S. furcifera, the full-length cDNA sequence of SfHMGR was obtained by RT-PCR. The expression profiles of SfHMGR in different developmental stages (1st-5th instar nymph and female adult) and different tissues (head, gut, fat body, ovaries and integument) of female adults of S. furcifera were detected by RT-qPCR. After targeted silencing of SfHMGR by RNAi technology, the ovarian development of female adults was observed, the number of eggs laid by per female adult of S. furcifera was counted, and the transcription levels of downstream genes of JH biosynthesis ( SfJHAMT and SfFAMeT), JH signal transduction related genes ( SfMet and SfKr-h1), and the key genes of ovarian development ( SfVg and SfVgR) were determined by RT-qPCR. 【Results】The full-length cDNA sequence of SfHMGR (GenBank accession number: MW883397) of S. furcifera was cloned, with an open reading frame of 2 724 bp in length, encoding 907 amino acids. The predicted molecular weight of the protein is 98.96 kD, and the theoretical isoelectric point is 6.15. Sequence analysis showed that SfHMGR contains typical HMG-CoA reductase conserved domain, three HMG-CoA binding sites at the C-terminus and seven transmembrane domains at the N-terminus. Phylogenetic analysis showed that SfHMGR has the closest genetic relationship with HMGR of Laodelphax striatellus and Nilaparvata lugens, showing 92.40% and 89.25% amino acid sequence identities with them, respectively. The developmental expression profiles showed that SfHMGR was highly expressed in the middle of various developmental stages and newly emerged female adults. The tissue expression profiles showed that SfHMGR was expressed in various tissues of female adults, and had the highest transcription level in gut. After the inhibition of SfHMGR expression by microinjection of dsRNA, the number of eggs laid by per female and ovarian development of female adults, and the transcription levels of SfJHAMT, SfFAMeT, SfKr-h1, SfVg and SfVgR were significantly inhibited. 【Conclusion】 SfHMGR regulates the transcription level of SfVg by affecting the JH biosynthesis process and JH signal transduction, and then affects the ovarian development and the fecundity of female adults of S. furcifera.

【Aim】 The Colorado potato beetle, Leptinotarsa decemlineata is an important quarantine pest in China, and it has serious harm to Solanaceae plants. This study aims to clarify the effects of late spring coldness and short-term low temperature on the growth of L. decemlineata population. 【Methods】 L. decemlineata eggs were exposed to low temperature of 8℃ for 1, 3 and 5 d, and those cultured at 27℃ were used as the control, and the egg hatching rate, growth and development of larvae and adult reproduction were investigated. The effects of short-term low temperature on the population growth of Colorado potato beetles were evaluated by population parameters.【Results】 When L. decemlineata eggs were exposed to low temperature of 8℃, the egg duration was significantly prolonged with the treatment time. The egg hatching rates in the treatment groups of 3 d and 5 d were significantly lower than that of the control, and the 1st instar larval duration in these two treatment groups was significantly longer than that of the control. However, the 2nd, 3rd and 4th instar larval and pupal duration was not significantly affected by the low temperature treatment of 8℃. After L. decemlineata eggs were exposed to low temperature of 8℃ for 5 d, the survival rates of the 1st instar larvae and adults were significantly lower than that of the control, but those of the other developmental stages in various treatment groups showed no significant difference. After L. decemlineata eggs were exposed to low temperature of 8℃ for 3 d, the intrinsic rate of increase ( r), finite rate of increase ( λ), and net reproductive rate ( R ₀) of population were significantly lower than those of the control and exposed to low temperature for 1 d, but the mean generation time ( T) in various treatment groups were not significantly different.【Conclusion】Short-term low temperature stress has adverse effects on the growth and development of L. decemlineata and slows down its population growth.

【Aim】 In low temperature environment, insects will activate the physiological regulation mechanism in vivo to stabilize their own metabolism, and fat metabolism plays an important role in the process of resisting low temperature in insects. This study aims to explore the changes in fat metabolism in Monochamus alternatus larvae under low temperature and its influence on the cold tolerance of M.  alternatus. 【Methods】 The 4th instar larvae of M. alternatus reared at the room temperature (25℃) were cultured in a constant temperature incubator at 25℃ (control) and 4℃ (cold acclimation), respectively. After 7 d, the larvae were dissected and their fat bodies were collected, the changes of lipid droplets were observed, and the fat content in the fat body was measured. The composition and content of free fatty acids were detected by gas chromatography-mass spectrometry (GC-MS), and the transcript levels of genes of key enzymes involved in fatty acid β-oxidation ［carnitine palmitoyltransferase 1 (CPT1), 4-ketoacyl-CoA thiolase (4KCT), very long chain acyl-CoA dehydrogenase (VLCAD), enoyl-CoA hydratase (ECH) and 3-hydroxyacyl-CoA dehydrogenase (3HCD-1)］ were assayed by RT-qPCR. 【Results】 After the 4th instar larvae of M. alternatus were subjected to cold acclimation (4℃) for 7 d, lipid droplets in the fat body became smaller, the lipid droplet density declined and the fat content decreased as compared to those in the control. However, the composition of fatty acids did not change. The main fatty acids in the fat body of the 4th instar larvae of both the control group and cold acclimation group were C16∶0, C16∶1, C18∶0, C18∶1 and C18∶2, of which the relative content of C18∶2 in both the two groups was the highest, decreasing from 31.83%±8.82% to 25.16%±2.88% after cold acclimation. After the 4th instar larvae of M. alternatus were subjected to cold acclimation, the relative contents of C16∶0, C16∶1 and C18∶2 in the fat body decreased, while the relative contents of C18∶0 and C18∶1 increased. Among the five main fatty acids, the relative abundance of various fatty acids in the fat body of the 4th instar larvae in the cold acclimation group was reduced compared with that in the control, of which the relative abundance of C16∶0, C16∶1 and C18∶2 decreased significantly. However, the double-bond index of free fatty acids in the fat body of the 4th instar larvae in the cold acclimation group was increased by 3.88% as compared to that in the control. The expression level of VLCAD gene in the cold acclimation group was significantly up-regulated as compared with that in the control group. 【Conclusion】 In low temperature environment, M. alternatus larvae maintain basic metabolism by consuming fat, and the degradation level of fatty acids in the fat body increased. Unsaturated fatty acids play a key role in the cold resistance of M. alternatus. Regulation of lipid metabolism is an important survival strategy for M. alternatus to cope with low temperature.

【Aim】 This study aims to improve the annotation of the genome of the Chinese oak silkworm, Antheraea pernyi, so as to expand its application to comparative genomics and breed improvement. 【Methods】 The full-length transcriptome of A. pernyi was sequenced and analyzed, and compared with the reference genome to identify novel genes and transcripts with functional annotation and to predict long non-coding RNAs (lncRNAs). The gene models in the genome of A. pernyi were modified by thousands of novel protein-coding transcripts and lncRNAs. Finally, the corrected and merged annotation of the genome of A. pernyi was created. 【Results】 A total of 1 997 novel protein-coding genes and 3 399 novel lncRNA genes were discovered and supported by 2 402 and 3 574 full-length transcripts, respectively. The genome of A. pernyi contains 25 021 genes, including 19 825 protein-coding genes, from which seven juvenile hormone acid O-methyltransferase genes were identified. 【Conclusion】 This study improves our knowledge of the known genes in the genome of A. pernyi and provides valuable resources for comparative and functional genomic studies in A. pernyi and its relatives.

【Aim】In honeybee colonies, both drones and queens have fully developed gonads, but they do not reach sexual maturity at the same time. The aim of this study is to explore the gene expression difference of gonads between drones and queens of the Asian honey bee, Apis cerana cerana. 【Methods】Illumina sequencing technology was used to analyze the differentially expressed genes (DEGs) in the transcriptome between testis of drone and ovary of queen of A. cerana cerana. 【Results】We identified 5 312 DEGs between testis and ovary of A. cerana cerana, among which 2 668 and 2 644 genes were up-regulated in testis and ovary, respectively. We also identified 11 candidate genes related to sex determination, spermatogenesis and oogenesis. These DEGs could be classified into 1 458 GO functional classes and 132 KEGG pathways with four GO entries and two KEGG pathways significantly enriched. 【Conclusion】These results provide valuable gene expression information for the study of the molecular mechanism of reproduction in A. cerana cerana.

【Aim】 The aim of this study is to determine the attractiveness of intestinal bacterium Klebsiella oxytoca to Drosophila suzukii, and to identify and verify the attractiveness of its volatile substances to D. suzukii adults. 【Methods】 The proportions of D. suzukii adults attracted by supernatants of K. oxytoca and NB medium (the control) as well as the proportions of female and male adults attracted in the presence or absence of host plant (Kyoho grape), respectively, were measured and analyzed. Volatile substances in the supernatant of K. oxytoca and NB medium were identified using HS-SPME-GC-MS methods. The attractiveness of four volatile substances of K. oxytoca supernatant with higher concentrations to D. suzukii adults was tested. 【Results】 D. suzukii adults were attracted to the supernatant of K. oxytoca. In the absence of host plant, the supernatant of K. oxytoca showed stronger attractiveness to male adults of D. suzukii than to female adults. However, in the presence of host plants, the numbers of female and male adults attracted by K. oxytoca supernatant were not significantly different. Twenty-one volatile substances were detected from K. oxytoca supernatant, among which 3-methyl-1-butyl alcohol, 2-phenylethyl alcohol, isoamyl acetate and indole had higher concentrations. D. suzukii adults showed taxis to 3-methyl-1-butyl alcohol, 2-phenylethyl alcohol and indole, but showed repellence to isoamyl acetate. The volatile substance 3-methyl-1-butyl alcohol could attract more male adults than female adults. 【Conclusion 】 Intestinal microorganism K. oxytoca supernatant can be used to attract D. suzukii adults, and 3-methyl-1-butyl alcohol is an important metabolite of K. oxytoca for attracting male adults of D. suzukii. This study provides some basic data for the control of D. suzukii.

 【Aim】 This study aims to determine the molecular characteristics of heat shock protein 70 (HSP70) genes in the small white butterfly, Pieris rapae and their response to insecticide stress, thus to pave the way for exploring the role of HSP70s in defense against insecticides in P. rapae. 【Methods】 Homology-basedsearchmethodwasusedtoidentifyHSP70 genes from the transcriptome dataset of P.  rapae. Bioinformatic programs were used to analyze the molecular characteristics of these HSP70 genes. Real-time quantitative PCR was performed to determine the expression profiles of HSP70 genes at different developmental stages (2nd-5th instar larvae, pupae, and female and male adults), in different tissues of the 4th instar larvae (midgut, Malpighian tubules, fat body and integument) of P. rapae, and in the 4th instar larvae exposed to LD₂₀ of lambda-cyhalothrin (0.12 ng/μL) and chlorantraniliprole (1.04 ng/μL). 【Results】 Three HSP70 genes (PrHsp70-1, PrHsp70-2 and PrHsp70-3 with the GenBank accession numbers of MW691114, MW691115 and MW691116, respectively) were identified from the transcriptome of P. rapae. PrHSP70 proteins encoded by PrHsp70-1, PrHsp70-2 and PrHsp70-3 consist of 628, 630 and 653 amino acid residues, respectively, and have the molecular masses of 68.7, 69.2 and 71.7 kD, respectively. The results of bioinformatic analysis indicated that all of the three PrHSP70 proteins are localized within the cytosol and have the signature motifs of HSP70 family. PrHsp70-1 and PrHsp70-2 are intronless, whereas PrHsp70-3 contains an intron. The expression levels of PrHsp70-1 and PrHsp70-2 were upregulated along with the increase of larval instars and downregulated during pupal and adult stages. By contrast, the expression levels of PrHsp70-3 in P. rapae among different developmental stages showed no significant difference. PrHsp70-1 and PrHsp70-2 were highly expressed in larval fat body and midgut, respectively, while PrHsp70-3 displayed higher transcription level in both larval integument and fat body. Treatment with LD₂₀ of lambda-cyhalothrin and chlorantraniliprole caused significant upregulation of the three PrHsp70 genes, although their responses varied with time. Moreover, the transcription level of PrHsp70-3 was significantly downregulated at 24 h post exposure to LD₂₀ of lambda-cyhalothrin. 【Conclusion】 PrHsp70 genes may play essential roles in the growth and development and insecticide defense in P. rapae.

【Aim】 This study aims to determine the role of a C-type lectin, RfCTL-S1, in immune defense in larvae of the red palm weevil, Rhynchophorus ferrugineus. 【Methods】 The sequence characteristics of RfCTL-S1 of R. ferrugineus were analyzed by bioinformatics methods. The expression levels of RfCTL-S1 across the different tissues (head, integument, foregut, mid-/hindgut, hemolymph and fat body) of the 4th instar larvae of R. ferrugineus were assayed by RT-qPCR. The abundance of RfCTL-S1 transcripts in the fat body and gut of the 4th instar larvae of R. ferrugineus challenged with Escherichia coli DH5α and Staphylococcus aureus by injection with 1 μL bacterial suspension with the OD₆₀₀ value of 1.6 was also detected by RT-qPCR. Moreover, the expression levels of the antimicrobial peptide genes, including RfAttacin, RfCecropin, RfColeopericin and RfDefensin, in the fat body and gut of the 4th instar larvae of R. ferrugineus after RNAi of RfCTL-S1 were also quantified by RT-qPCR. After RfCTL-S1 was silenced by RNAi, the ability of R. ferrugineus individuals to clear the invaded EGFP-tagged E. coli in the hemolymph and the number of cultivable bacterial colonies in the gut of the 4th instar larvae of R. ferrugineus were evaluated. 【Results】 The bioinformatics analysis revealed that RfCTL-S1 contains a signal peptide and the carbohydrate recognition domain (CRD) with EPN motif, but without transmembrane domain, suggesting that RfCTL-S1 is a secretory protein with mannose-binding activity. RT-qPCR results showed that RfCTL-S1 was highly expressed in the hemolymph of the 4th instar larvae of R. ferrugineus. In the fat body of R. ferrugineus larvae at 24 h after injection of E. coli, the expression level of RfCTL-S1 was significantly down-regulated as compared with that of the control injected with PBS. The expression level of RfCTL-S1 in the fat body of R. ferrugineus larvae at 6 h after injection of S. aureus was significantly higher than that at 24 h after injection of S. aureus. In the gut of R. ferrugineus larvae, the expression level of RfCTL-S1 at 12 h after challenge with S. aureus was significantly higher than those at 6 and 24 h after challenge with S. aureus. After RfCTL-S1 was silenced by RNAi, the expression levels of three antimicrobial peptide genes RfCecropin, RfColeoptericin and RfDefensin in the fat body of R. ferrugineus larvae were significantly reduced, and the ability of R. ferrugineus larvae to clear the invaded EGFP-tagged E. coli in the hemolymph was significantly impaired as compared to the control. However, no significant difference was determined in the number of cultivable bacterial colonies in the larval gut between the RNAi group and the control group. 【Conclusion】 Secretory RfCTL-S1 protein can mount the expression of antimicrobial peptide genes by recognizing bacteria and activating the corresponding immune signaling pathways in the fat body of R. ferrugineus larvae, thus to eliminate invaded pathogens.

【Aim】 Secondary endosymbionts may affect the susceptibility of Bemisia tabaci to insecticides. This study aims to reveal the influence of endosymbiont Cardinium infection on the insecticide tolerance of B. tabaci MED. 【Methods】 The tolerance of Cardinium-infected and uninfected lines with identical genetic background of two populations of B. tabaci MED (Lingshui population from Lingshui, Hainan Province, South China, and Shouguang population from Shouguang, Shandong Province, North China) to different concentrations of two neonicotinoid insecticides (thiamethoxam and imidacloprid) was assayed in the laboratory. 【Results】 After treatment with various concentrations of thiamethoxam and imidacloprid, respectively, the mortalities of the Cardinium-infected line of Lingshui population were significantly lower than those of the uninfected line. After exposure to 100, 150, 175 and 200 mg/L thiamethoxam and 175 and 200 mg/L imidacloprid, respectively, the mortalities of the Cardinium-infected line of Shouguang population were significantly higher than those of the uninfected line. Compared with the uninfected line, the resistance ratios of the Cardinium-infected line of Lingshui population under the pressure of thiamethoxam and imidacloprid were 1.355 and 1.847, respectively, while those of Cardinium-infected line of Shouguang population were 0.790 and 0.847, respectively. 【Conclusion】 Endosymbiont Cardinium infection can significantly influence the tolerance of B. tabaci MED to thiamethoxam and imidacloprid, and the influence varies among its different populations. The results provide valuable references for revealing the population adaptability and expansion mechanism of B. tabaci MED.

【Aim】 To clarify the feeding behaviors of Therioaphis trifolii on different cultivars of alfalfa ( Medicago sativa), to ascertain the anti-aphid factors and insect resistance sites, and to screen out the M. sati va cultivars resistant to aphids. 【Methods】 The feeding behaviors of T. trifolii adults on 10 alfalfa cultivars were recorded using electrical penetration graph (EPG) technology, appropriate EPG parameters were selected based on clustering analysis and aphid resistance was evaluated with these EPG parameters. 【Results】 T. trifolii adults fed on different alfalfa cultivars showed eight waveforms including np waveform, pd waveform, A waveform, B waveform, C waveform, E waveform, F waveform and G waveform, and the total duration of E waveform, F waveform and G waveform of T. trifolii adults on different alfalfa cultivars showed significant differences. During the 5 h test period, the duration of E waveform on Aohan was the longest, followed by that on Golden Empress and Zhongmu No.3, and that on Caoyuan No.2 and Algonquin was the shortest. The total duration of F waveform on Zhungeer, Algonquin and Golden Empress was the longest, and that on Aohan, Derby and Caoyuan No. 2 was the shortest, suggesting that the formers have strong mechanical resistance and the latters have weak mechanical resistance. Using the duration of the first probe, total duration of probe wave, total duration of F waveform, total duration of C waveform, and total duration of E waveform as indices for cluster analysis, 10 alfalfa cultivars were clustered into 3 categories: Algonquin, Caoyuan No. 2, WL168HQ, Derby, Zhongmu No. 2 and Xinmu No. 2 in category I, Golden Empress, Zhongmu No. 3 and Zhungeer in category II, and Aohan in category III. 【Conclusion】 The feeding behaviors of T. trifolii adults on different alfalfa cultivars are different. The alfalfa cultivars Caoyuan No. 2, Algonquin and WL168HQ show resistance to T. trifolii adults at the levels of leaf epidermis, mesophyll and phloem, and Golden Empress shows resistance to T. trifolii adults when leaf epidermis and mesophyll are pierced. T. trifolii adults can pierce and suck for a long time on Aohan, so Aohan shows the lowest resistance to T. trifolii adults. This study provides a theoretical basis for further exploring the mechanisms of alfalfa resistance to insects and the integrated control of aphids.

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

 【Aim】 The typical single-chromosome mitochondrial (mt) genome of animals has fragmented into multiple mt minichromosomes in Hoplopleura genus. To infer the ancestral mt karyotype for Hoplopleura genus, we sequenced the mt genome of Hoplopleura pacifica. 【Methods】 We sequenced the fragmented mt genome of H. pacifica by Illumina HiSeq X Ten platform, and analyzed the structure and variation. We constructed phylogenetic trees of 15 species of sucking lice in 7 genera and 7 families by using maximum likelihood method and neighbor-joining method, and inferred the ancestral mt karyotype of Hoplopleura by parsimony method. 【Results】 We identified 29 mt genes (11 protein-coding genes, 16 tRNA genes and 2 rRNA genes) from mt genome of H. pacifica, which are unevenly distributed on 10 mt minichromosomes. The coding region of each mt minichromosome contains 1-5 genes with the length of 690-1 773 bp. Species of Hoplopleura have a little difference in structure of mt minichromosomes. Compared with other genera in Anoplura, Hoplopleura have variation in the gene composition and gene arrangement of mt minichromosome, which, however are only limited to tRNA genes. The phylogenetic tree showed that Anoplura was divided into two major clades with strong supports, one major clade included the lice of Hoplopleuridae, Polyplacidae, Haematopinidae and Microthoraciidae, and the other major clade included the lice of Pediculidae, Pthiridae, and Pedicinidae. The ancestral mt karyotype of Hoplopleura comprises 12 mt minichromosomes, each having a single coding region with 1-6 genes and a single non-coding region. 【Conclusion】 We successfully sequenced and analyzed the fragmented mt genome of H. pacifica for the first time, compared it with the mt genome of the other two Hoplopleura species sequenced to date, and inferred the ancestral mt karyotype of Hoplopleura.

【Aim】 ATP-binding cassette transporter (ABC transporter), a huge superfamily of membrane transporters, plays an important role in insect growth, development and insecticide resistance. This study aims to provide theoretical basis for subsequent functional studies by cloning ABCD1 of the white-backed planthopper, Sogatella furcifera and determining its expression pattern under insecticide stress. 【Methods】 The cDNA sequence of ABCD1 of S. furcifera was cloned by RT-PCR, and subjected to bioinformatics analysis. The expression levels of ABCD1 in S. furcifera at different developmental stages (1st-5th instar nymphs and 1-4 day-old male and female adults), in different tissues (head, integument, fat body, gut, leg, wing, testis and ovary) of the 5th instar nymphs and adults, and in the 3rd instar nymphs exposed to different concentrations (LC ₁₀, LC ₂₅, LC ₅₀ and LC ₉₀) of thiamethoxam, buprofezin, and abamectin were detected by RT-qPCR. 【Results】 An ABC transporter gene of S. furcifera was obtained and named SfABCD1 (GenBank accession no.: MW701394), with an open reading frame of 2 220 bp in length. It encodes a putative protein of 739 amino acid residues with the predicted molecular weight of 82.08 kD and isoelectric point of 9.32. SfABCD1 is closely related to ABCD1 of Laodelphax striatellus and Nilaparvata lugens. RT-qPCR results showed that SfABCD1 had the highest expression level in the 5th instar nymphs and was expressed in various tissues of the 5th instar nymphs and adults with the highest expression level in the gut and head of the 5th instar nymphs. After the 3rd instar nymphs were exposed to insecticides for 48 h, the expression levels of SfABCD1 in the treatment groups of buprofezin at the concentrations of LC ₁₀, LC ₅₀ and LC ₉₀, thiamethoxam at the concentrations of LC ₁₀, LC ₂₅ and LC ₅₀ and abamectin at the concentrations of LC ₅₀ and LC ₉₀ were significantly up-regulated as compared to that in the control group treated with water. When the 3rd instar nymphs were exposed to the three insecticides at the four concentrations of LC ₁₀, LC ₂₅, LC ₅₀ and LC ₉₀ for different time, the expression difference of SfABCD1 in the nymphs between the treatment group and the control group were the largest at 48 h after treatment and subsequently decreased at 96 h after treatment, and then the expression level of this gene in nymphs at 120 h after treatment was close to that in the control group. 【Conclusion】 S. furcifera can respond to the stress of buprofezin and thiamethoxam by up-regulating the expression of SfABCD1, and the expression level of SfABCD1 decreases with the increase of the concentration of thiamethoxam. In addition, S. furcifera also responds to the poison of high concentrations of abamectin by regulating the transcription level of SfABCD1.