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  • Monthly, Founded in 1950
    Supervisor:Chinese Academy of Sciences
    Sponsor:Institute of Zoology,Chinese Academy of Sciences
    The Entomological Society of China
    Domestic postal code: 2-153
    Foreign issuance code: Q61
    ISSN 0454-6296
    CN 11-1832/Q
Table of Content
20 April 2020, Volume 63 Issue 4
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  • RESEARCH PAPERS
    Molecular cloning, prokaryotic expression and expression profiling of the laccase gene MaLac1 in Monochamus alternatus (Coleoptera: Cerambycidae)
    CHEN Hao, LUO Qiao-Yu, MA Qiu-Yu, CHU Xu, YUAN Chao, LIU Ying, YU Wei, WU Song-Qing, WANG Rong, LIANG Guang-Hong, ZHANG Fei-Ping, HU Xia
    2020, 63(4):  381-389.  doi:10.16380/j.kcxb.2020.04.001
    Abstract ( 795 )   PDF (2548KB) ( 259 )   PDF(mobile) (2548KB) ( 66 )     
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    【Aim】 This study aims to clone and identify the laccase gene MaLac1 from the Japanese pine sawyer, Monochamus alternatus, and to analyze its expression levels in different developmental stages of the beetle, so as to provide some clues for further study of the function of MaLac1. 【Methods】 Based on the transcriptome sequencing data of M. alternatus gut, the full-length cDNA of MaLac1 was cloned from M. alternatus using the RACE method and analyzed by bioinformatic software. MaLac1 sequence was then inserted into the prokaryotic expression vector pET-32a(+) to construct a recombinant plasmid pET-MaLac1, which was then transformed into Escherichia coli Rosetta (DE3) to express MaLac1. The expression patterns of MaLac1 in the gut of M. alternatus at different developmental stages (early instar larva, mature larva, pupa, female adult, and male adult) were assayed by qPCR. 【Results】 The full-length cDNA of MaLac1 from M. alternatus (GenBank accession no.: KY073340) were obtained. Its open reading frame is 2 067 bp in length, encoding a protein of 688 amino acids, with an estimated molecular mass of 78.34 kD and an isoeletric point of 5.30. MaLac1 was predicted to contain an N-terminal signal peptide with 15 amino acids by SignalP 4.1 Server. Sequence alignment analysis showed that MaLac1 shows the typical characteristics of insect laccase genes, with 93% amino acid sequence identity with the laccase gene of Tribolium castaneum. SDS-PAGE results showed that IPTG induced a specific protein band of about 78 kD, which was consistent with the estimated size. The qPCR results showed that MaLac1 was expressed in the gut of M. alternatus at various developmental stages, with the highest expression level in the female adult gut, followed by that in the male adult gut, and the lowest expression level in the larval gut. 【Conclusion】 The expression level of MaLac1 in adults of M. alternatus is significantly higher than that in larvae, and this may be relevant to the feeding differences between adults and larvae. Further study is needed to reveal the exact function of MaLac1 in M. alternatus
    Cloning, prokaryotic expression and tissue expression profiling of odorant binding protein gene AzanOBP3 from Agrilus zanthoxylumi (Coleoptera: Buprestidae)
    GONG Xue-Fang, YANG Ping, WANG Yan-Lai, GUO Li, CHEN Di, XIE Shou-An, LÜ Shu-Jie
    2020, 63(4):  390-400.  doi:10.16380/j.kcxb.2020.04.002
    Abstract ( 634 )   PDF (2563KB) ( 137 )   PDF(mobile) (2563KB) ( 48 )     
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    【Aim】 The objective of this study is to clone the coding sequence of odorant binding protein (OBP) gene Azan OBP3 in Agrilus zanthoxylumi and to analyze its structure properties and expression profile, so as to further understand the process of identifying 
    odorant substances in A. zanthoxylumi adult antennae and to provide a new fundamental evidence for the pest management and control. 【Methods】 The cDNA sequence of AzanOBP3 was amplified from A. zanthoxylumi with RT-PCR, and the nucleotide and deduced amino acid sequences of the gene were analyzed using different bioinformatics software. The recombinant expression vector pET-28a(+)/AzanOBP3 was constructed and transformed into Escherichia coli BL21(DE3) competent cells for expression by IPIG iduction. The recombinant protein was identified by SDS-PAGE and Western blotting. The expression profiles of AzanOBP3 in different female and male adult tissues (head, thorax, abdomen, leg and wing) of A. zanthoxylumi were detected by qPCR. 【Results】 We cloned the full-length cDNA sequence of AzanOBP3 (GenBank accession no.: MT318832) from A. zanthoxylumi. Its ORF is 414 bp in length, encoding 137 amino acids, with a predicted molecular weight of 16.038 kD and the isoelectric point of 4.79, and a signal peptide sequence of 29 amino acids at the N terminus. The encoded protein has six conserved cysteines belonging to the typical insect OBPs. Homologous sequence alignment analyses showed that AzanOBP3 has the highest amino acid sequence identity with AmalOBP2 from Agrilus mali and AplaGOBP from Agrilus planipennis (74.45% and 76.92%, respectively). The recombinant expression vector pET-28a(+)/AzanOBP3 was successfully constructed and the target protein was stably expressed in host bacteria in the form of fusion protein after culture at 37℃ 180 r/min in a shaker incubator and induction with 1 mmol/L IPTG for 4 h. The qPCR results revealed that AzanOBPwas expressed in various tissues of male and female adults of A. zanthoxylumi, with the highest expression level in the male adult leg. 【Conclusion】 In this study, the nucleotide and amino acid sequences of AzanOBP3 and the physiochemical properties of its encoded protein were clarified. The tissue expression profile suggests that AzanOBP3 may not be limited to the recognition of olfactory odorant, also have physiological functions in non-olfactory tissues, and especially may play important roles during insect feeding and host locating. Its functions need further study. This study provides a basis for exploring the molecular structure of odorant binding proteins and their functional mechanisms in the chemical sensing system of A. zanthoxylumi.
    Cloning of juvenile hormone esterase and juvenile hormone epoxide hydrolase genes and their expression dynamics during diapause and metamorphosis in Sitodiplosis mosellana (Diptera: Cecidomyiidae)
    WANG Jing-Jing, LIANG Ting-Ting, CHENG Wei-Ning, ZHU Ke-Yan
    2020, 63(4):  401-412.  doi:10.16380/j.kcxb.2020.04.003
    Abstract ( 701 )   PDF (3362KB) ( 103 )   PDF(mobile) (3362KB) ( 26 )     
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    【Aim】 Juvenile hormone (JH) plays important roles in diapause induction, maintenance and post-diapause quiescence of the wheat midge, Sitodiplosis mosellana, an insect species undergoing obligatory larval diapause. Juvenile hormone esterase (JHE) and juvenile hormone epoxide hydrolase (JHEH) are important JH degradation enzymes that play key roles in regulating insect JH titers. This study aims to explore the potential roles of JHE and JHEH in the diapause and metamorphosis of S. mosellana. 【Methods】 The full-length cDNAs of JHE and JHEH were cloned from pre-diapause larvae of S. mosellana by RT-PCR and RACE technologies. The sequence characteristics of nucleotide and amino acid sequences of the cloned JHE and JHEH were analyzed by bioinformatics software. The 
    expression levels of JHE and JHEH in the 3rd instar larvae of S. mosellana at different diapause stages (pre-diapause, diapause, post-diapause quiescent and post-diapause development) and different developmental stages from the 1st instar larva to adult  (the 1st-2nd instar larva, pre-pupa, early pupa, middle pupa, late pupa, male adult and female adult) were determined by qPCR. 【Results】 The full-length cDNA sequences of JHE and JHEH  were obtained from S. mosellana and named SmJHE and SmJHEH (GenBank accession number: MG876768 and MG876769, respectively), with the length of 3 102 and 1 980 bp, respectively. SmJHE and SmJHEH contain 1 740 and 1 371 bp ORFs, respectively, which encode the proteins of 579 and 456 amino acids with the predicted molecular weights of 65.67 and 51.65 kD, respectively. SmJHE contains five specific conserved motifs of JHE protein family, and all of the conserved domains of JHEHs including the residues Asp228, Asp404 and His431 in the catalytic triad, and two Tyr residues (Tyr299 and Tyr374) and the HGWP motif corresponding to the oxyanion hole. Multiple sequence alignment and phylogenetic analysis showed that SmJHE and SmJHEH have higher amino acid sequence identity and the closest relationship to the corresponding homologues from Nematocera insects of Diptera. The expression levels of SmJHE and SmJHEH showed no significant change at the pre-diapause stage (the 1st, 2nd and early 3rd instar larval stages), remained stable after entering diapause, but were the lowest at the post-diapause quiescence phase (from December to the next January). The expression of SmJHE increased gradually after development resumption, reached the peak in the pre-pupal stage, and was significantly lower in female adults than in male adults. The expression of SmJHEH, however, reached the highest in female adults and the lowest in pre-pupae. 【Conclusion】 SmJHE and SmJHEH are involved in diapause of S. mosellana. Their reduced expression during diapause might be related to accumulation of JH titers in post-diapause quiescence. Increased expression of SmJHE during the development process of S. mosellana might play a role in metamorphosis from larva to pupa, and its reduced expression might be related to reproductive development.
    Projection of major pheromone tuned olfactory receptor neurons of Helicoverpa armigera (Lepidoptera: Noctuidae) revealed by using single sensillum recording and staining
    MA Bai-Wei, LIU Xiao-Lan, CHANG Ya-Jun, XIE Gui-Ying, CHEN Wen-Bo, LIU Yang, ZHAO Xin-Cheng, WANG Gui-Rong
    2020, 63(4):  413-420.  doi:10.16380/j.kcxb.2020.04.004
    Abstract ( 666 )   PDF (3405KB) ( 179 )   PDF(mobile) (3405KB) ( 40 )     
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    【Aim】 To characterize the function and morphology of major pheromone tuned olfactory receptor neurons and their central projection to the brain in the cotton bollworm, Helicoverpa armigera. 【Methods】 Single sensillum recording was used to record the response of major pheromone tuned olfactory receptor neurons to sex pheromones, and staining with a fluorescent dye used to label the neurons. Immunohistochemistry was used to label the antennal lobe glomeruli. Laser scanning confocal microscope was used to acquire the images of antennal lobes with stained neurons, and the image software ZEN and Amira 4.1.1 was used to analyze the data. 【Results】 Obvious electrophysiological responses of trichoidea sensilla on the antennae of male adults of H. armigera to the major pheromone component Z11-16∶Ald were recorded, and the olfactory receptor neurons housed in the sensilla were successfully labeled by staining. Two olfactory receptor neurons were observed in Z11-16∶Ald-responsive sensllium. The axons of these two olfactory receptor neurons project via the antennal nerve to the cumulus and an ordinary glomerulus in the antennal lobe, respectively. 【Conclusion】 The combination of single sensillum recording and staining with the fluorescent dye can be applied in the identification of the function and morphology of olfactory receptor neurons housed in the antennal sensilla of insects and their central projection pathway to the antennal lobe glomeruli. Compared with the cobalt-lysine, the staining with fluorescent dye is more practical and facilitates the image acquisition and three-dimensional reconstruction. Such method provides technical support for the investigation on the projection pathway of other olfactory receptor neurons of H. armigera to determine the relationship between the peripheral odor receptor perception and the central nervous system.
    Morphology, histology and ultrastructure of the alimentary canal of the adult mute cicada, Karenia caelatata (Hemiptera: Cicadidae) (In English)
    ZHONG Hai-Ying, ZHANG Ya-Lin, WEI Cong
    2020, 63(4):  421-432.  doi:10.16380/j.kcxb.2020.04.005
    Abstract ( 748 )   PDF (21175KB) ( 133 )   PDF(mobile) (21175KB) ( 313 )     
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    【Aim】In order to better understand the morphology and function of alimentary canal of insects in Cicadidae, the alimentary canal of the mute cicada, Karenia caelatata, was investigated at the morphological, histological and ultrastructural levels. 【Methods】 The gross morphology of alimentary canal, ultrastructure of associated organs including oesophagus, filter chamber (including anterior and posterior extremities of the midgut, internal proximal extremity of the ileum, and internal proximal extremities of the Malpighian tubules), conical segment, a midgut loop, and hindgut (ileum and rectum), and histology of filter chamber of male adult of K. caelatata were observed using light and transmission electron microscopy. 【Results】 The results showed that the alimentary canal of K. caelatata consists of the oesophagus, filter chamber, external midgut section and hindgut. The elongated oesophagus is lined with a cuticle containing an epicuticle and an endocuticle. The filter chamber is enveloped by a thin filter chamber sheath, which contains the anterior and posterior extremities of the midgut, internal proximal extremity of the ileum and internal proximal extremities of the Malpighian tubules. Cells of the anterior and posterior extremities of the midgut possess well-developed basal infoldings and densely-packed apical microvilli. Numerous mitochondria and electron-dense secretory granules were observed in the posterior extremity of the midgut. The external midgut section contains a conical segment and a midgut loop. The conical segment is dilated, and consists of two types of cells: the first is featured by the well-developed basal infoldings, and the second lacks basal infoldings. The midgut loop is divided into three distinct regions, i.e., the anterior segment containing numerous secretory granules, mitochondria, rough endoplasmic reticulum and lysosomes in the cytoplasm, the mid-segment containing secretory granules in the cytoplasm, and the posterior segment with cells possessing numerous electron-lucent secretory granules and smooth endoplasmic reticulum. Ferritin-like granules scatter in the cells of the anterior segment and mid-segment of the midgut loop. Filamentous materials coat the microvilli of the cells of the conical and anterior segments of the midgut loop. The hindgut is lined by a layer of cuticle. Microorganisms reside in the oesophagus, mid-segment of the midgut loop and rectum cells. 【Conclusion】 Findings of the morphological, histological  and ultrastructural characteristics of the gut alimentary canal of K. caelatata  in this study improve our understanding of the functional differentiation of alimentary canal in this species. The discovery of microorganisms in the alimentary canal is formative to future study of coevolution between the Cicadoidea and related bacteria.
    Differences in ovarian and embryonic development between alate and apterous morphs of the soybean aphid, Aphis glycines(Hemiptera: Aphididae)
    XU Xiang-Li, WU Jun-Xiang
    2020, 63(4):  433-438.  doi:10.16380/j.kcxb.2020.04.006
    Abstract ( 544 )   PDF (3332KB) ( 148 )   PDF(mobile) (3332KB) ( 14 )     
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    【Aim】 The ovarian development of alate and apterous morphs of the soybean aphid, Aphis glycines was compared to provide a biochemical basis for the reproductive fitness of wing morph differentiation. 【Methods】 Based on the ovarian morphology observed 
    under microscope, the number of ovarioles, total number of embryos, number of mature embryos, and the volume of the largest embryo in each ovariole of A. glycines were compared for alate and apterous morphs. 【Results】 There are two ovaries per female of alate and apterous morphs of A. glycines at the 3rd and 4th instar nymphal and adult stages. Most aphids contain four ovarioles per ovary, and only one ovary was found to contain five. The total number of embryos and number of mature embryos and the volume of the largest embryo increases significantly with increasing developmental period of both wing morphs. However, the total number of embryos and number of mature embryos are significantly lower, and the volume of the largest embryo is significantly smaller in alate than in apterous individuals at the same stage, respectively. There is a significantly positive relationship between the 
    total number of embryos and the hind tibia length of alate and apterous morphs of A. glycines at the 3rd and 4th instar nymphal and adult stages. Alate and apterous aphids show an exponential growth in the volume of the largest embryo. However, the largest embryo of alate aphids is distinctly smaller than that of apterous aphids. 【Conclusions】 Alate aphids of A. glycines display a delay in the ovarian development as compared to apterous aphids, and the difference in ovarian development degree between them may be related to wing development.
    Observation of antennal sensilla of flower-visiting insect Bibio rufiventris (Diptera: Bibionidae) with scanning electron microscope
    YUAN Ke, ZHU Hui, QU Ye-Kuan, REN Bing-Zhong, YOU Yang
    2020, 63(4):  439-449.  doi:10.16380/j.kcxb.2020.04.007
    Abstract ( 807 )   PDF (1408KB) ( 148 )   PDF(mobile) (1408KB) ( 25 )     
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    【Aim】 This study aims to clarify the types and distribution of antennal sensilla of flower-visiting insect Bibio rufiventris. 【Methods】 The type, quantity and morphology of antennal sensilla of B. rufiventris were observed with scanning electron microscope (SEM), and their differences between male and female adults were compared. 【Results】 The female and male adult antennae of B. rufiventris include three parts, scape (Sc), pedicel (P) and flagellum (F), and the flagellum consists of eight flagellomeres. The average lengths of antennae of female and male adults are 862.556±78.662 and 880.361±83.253 μm, respectively. There is significant difference in the length of the 8th flagellomere, while the lengths of other flagellomeres are almost equal. Four types of sensilla including sensilla chaetica (Sc), sensilla basiconca (Sb), sensilla trichodea (St) and Böhm bristles (Bb) were observed on the female and male antennae. The antennal sensilla of female adults have six subtypes, i.e., sensilla chaetica (Sc), sensilla trichodea subtype 2 (St.2), sensilla basiconca subtypes 1, 2 and 4 (Sb.1, Sb.2 and Sb.4) and Böhm bristles (Bb), while those of male adults have five subtypes, i.e., sensilla chaetica (Sc), sensilla trichodea subtype 1 (St.1), sensilla basiconca subtype 2  (Sb.2) and sensilla basiconca subtype 3 (Sb.3) and Böhm bristles (Bb). 【Conclusion】 The types, amounts and characteristics of antennal sensilla of B. rufiventris adults show some 
    differences between females and males. This study provides a morphological basis for studying the physiological functions of these sensilla and the molecular mechanisms of behavioral activities of B. rufiventris
    Diversity analysis and function prediction of gut microbiota in three springtail species
    CHEN Wei, CHEN Xia, LI Juan, MA Xin-Ran, CUI Wei, QU Feng-Tian, XIE Gui-Lin, ZHAO Hong-Qing
    2020, 63(4):  450-461.  doi:10.16380/j.kcxb.2020.04.008
    Abstract ( 918 )   PDF (8308KB) ( 150 )   PDF(mobile) (8308KB) ( 49 )     
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    【Aim】 Springtails make a significant contribution to the soil ecosystem. This study aims to investigate the gut microbial structure and diversity and their potential functions in three springtail species, Sinella (Coecobrya) oligoseta, Proisotoma minuta and Tomocerus missus. 【Methods】 Microbes in the adult intestinal contents of the three springtail species were analyzed and compared by 16S rDNA amplicon sequencing, and the function prediction of gut microbial genes was conducted using Tax4Fun method. 【Results】Among the three springtail species, T. missus showed the highest adult gut microbial diversity, while S. (C.) oligoseta showed the lowest adult gut microbial diversity. At the phylum level, Proteobacteria, Firmicutes and Bacteroidetes were the most predominant microbes in the adult gut microbiota of the three springtail species, followed by Actinobacteria. At the genus level, the abundance of Pseudomonas in the gut of S. (C.) oligoseta (16.21%) was significantly higher than those in the guts of P. minuta (0.87%) and T. missus (1.37%). The abundance of Vibrio in the gut of P. minuta (25.81%) was significantly higher than that in the gut of S. (C.) oligoseta (3.35%) and T. missus (0.004%). Additionally, based on KEGG pathway annotations, we predicted that the genes in adult gut microbiota of the three springtail species may be involved in the metabolism of carbohydrates and amino acids, infectious diseases and drug resistance. 【Conclusion】 In the intestines of the three springtail species, S. (C.) oligoseta, P. minuta and T. missusthe core microbiota are the same at the phylum level, but obviously different at the genus level. The influencing factors should include the genetic traits and the abundance and diversity of microbes in the habitat of each species. Actinomycetes in springtail guts are conducive to the discovery of new strains and the application of their metabolites. Drug-resistant and pathogenic bacteria likely exist in the intestines of the three springtail species, implying new directions of functional studies on gut microbiota in springtails.
    Effects of intestinal bacteria Citrobacter freundi and Klebsiella oxytoca on the development and substance metabolism of Drosophila suzukii (Diptera: Drosophilidae) 
    GAO Huan-Huan, QIN Dong-Yun, DAI Xiao-Yan, LIU Jie, YU Yi
    2020, 63(4):  462-469.  doi:10.16380/j.kcxb.2020.04.009
    Abstract ( 700 )   PDF (1918KB) ( 75 )   PDF(mobile) (1918KB) ( 19 )     
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     【Aim】 To understand the effect of the intestinal symbiotic bacteria Citrobacter freundi and Klebsiella oxytoca on the development and substance metabolism of the spotted wing drosophila, Drosophila suzukii. 【Methods】 The egg hatching rates, body weight of the 3rd instar larvae and pupation rates of the normal D. suzukii strain, sterile D. suzukii strain, C. freundi infected D. suzukii strain and K. oxytoca infected D. suzukii strain were determined. The contents of metabolites including protein, amino acids, glycogen and 
    free fatty acids and the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the 3rd instar larvae of these D. suzukii strains were detected. 【Results】 The egg hatching rate, body weight of the 3rd instar larvae, pupation rate and 
    protein content in the 3rd instar larvae of the normal D. suzukii strain were all higher than those of other strains, while those of the sterile D. suzukii strain were the lowest. The 3rd instar larvae of D. suzukii strains infected by C. freundi or K. oxytoca had lower 
    contents of amino acids and glycogen than the sterile and normal D. suzukii strains. The contents of free fatty acids in the 3rd instar larvae of D. suzukii infected by C. freundi were also lower than those in the other D. suzukii strains. In the 3rd instar larvae of D. 
    suzukii strains infected by C. freundi or K. oxytoca, the POD activity was significantly higher than those in the sterile and normal strains, while the CAT activity was significantly lower than those in the sterile strain. 【Conclusion】 The development of D. 
    suzukii delays in the absence of intestinal symbiotic bacteria. However, the development of D. suzukii can be enhanced in some extent after adding C. freundi or K. oxytoca in the food, and this is closely related to the changes of metabolites in D. suzukii after adding 
    intestinal bacteria.
    Transcriptomic analysis of insecticide target and detoxification related genes in Adoxophyes orana (Lepidoptera: Tortricidae)
    SUN Li-Na, ZHANG Huai-Jiang, LIU Xiao-He, QIU Gui-Sheng
    2020, 63(4):  470-481.  doi:10.16380/j.kcxb.2020.04.010
    Abstract ( 571 )   PDF(mobile) (3688KB) ( 114 )     
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     【Aim】 To establish the transcriptome database of Adoxophyes orana, and to explore insecticide target and detoxification related genes. 【Methods】 The transcriptome of A. orana was sequenced by Illumina HiSeqTM 2000 sequencing platform to explore insecticide target genes. The expression levels of six insecticide target genes from A. ornan at different developmental stages including egg, larva, pupa and adult were identified and verified using qPCR. The metabolic pathway and evolutionary relationship of 
    detoxification related genes in the transcriptome of A. orana were analyzed. 【Results】 A total of 48 610 unigenes (GenBank accession no.: GGMW00000000) were identified by assembling valid sequences. One hundred and fifty-five insecticides target genes were identified. The qPCR results confirmed that there was difference in the expression levels of six insecticide target genes including one ecdysone receptor (ECR) gene, two acetylcholinesterase (AChE) genes, one chloride channel (CLC) gene, one chitinase (CS) gene 
    and one ryanodine receptor (RyR) gene at different developmental stages of A. ornanAdditionally, 69 carboxylesterase (CarE) unigenes, 66 glutathion S-transferase (GST) unigenes and 205 cytochrome P450 unigenes were identified. A total of 20 CarE, 32 GST and 30 P450 unigenes were classified into the metabolism categories related to toxic substance metabolism. The results of cluster analyses based on the amino acid sequences of unigenes with complete ORF showed that 9 of 12 CarEs were classified to G class (Lepidoptera neotenin), 10 AoGSTs into subfamily Delta and another 10 AoGSTs into subfamily Epsilon, and all of 18 P450s into CYP3 group. 【Conclusion】 This study contributes to the discovery of insecticide target genes and the research of pesticide resistance in A. orana.
    Screening and evaluation of semiochemical mixtures attracting Holotrichia oblita (Coleoptera: Melolonthidae)
    LI Xiao-Feng, LI Jin-Qiao, CAO Ya-Zhong, YIN Jiao, ZHANG Shuai, QIN Jian-Hui, WANG Si-Yu, LU Jun-Jiao, LI Ke-Bin
    2020, 63(4):  482-493.  doi:10.16380/j.kcxb.2020.04.011
    Abstract ( 602 )   PDF (1782KB) ( 86 )   PDF(mobile) (1782KB) ( 22 )     
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    【Aim】 To find effective attractant formulations for trapping Holotrichia oblita for ecological prevention and control. 【Methods】 Five plant volatiles, two aggregation pheromones and one sex pheromone were selected. According to the optimal concentration of each chemical, these compounds were mixed in pairs. A total of 17 binary attractant formulations were obtained, including plant volatiles plus aggregation pheromones, plant volatiles plus sex pheromones and aggregation pheromones plus sex pheromones. Based on the electro-antennogram (EAG) and taxis, the formulations with high attractiveness to H. oblita adults were gradually screened. Then, the trapping efficacies of these formulations and their single components on H. oblita adults were compared, and the attractiveness of these formulations was tested by trapping test in the indoor cage. 【Results】 Three binary attractant formulations cis-3-hexenyl acetate+(Z)-9-octadecene acetate, 1-hexanol+(Z)-9-octadecene acetate, and dibutyl phthalate+methyl glycate with strong attractiveness to H. oblita adults were screened from 17 attractant formulations by EAG and taxis tests, causing the EAG responses of 5 981%, 5 796% and 5 722%, respectively, in females, and 3 983%, 4 712% and 3 809%, respectively, in males. The formulation dibutyl phthalate+methyl glycate caused the highest selective response rate (71.21%) in H. oblita adults, followed by the formulations 1-hexanol+(Z)-9-octadecene acetate and cis-3-hexenyl acetate+(Z)-9-octadecene acetate (70.84% and 70.72%, respectively), causing significantly higher selective response rate than other formulations. The results of comparison of attractiveness between three formulations and their single components showed that the formulation cis-3-hexenyl acetate+(Z)-9-octadecene acetate showed significant synergistic effect on cis-3-hexenyl acetate but showed no significant synergistic effect on cis-9-octadecyl acetate. Both the formulations 1-hexanol+(Z)-9-octadecene acetate and dibutyl phthalate+methyl glycate showed significant synergistic effect on their respective single components. The results of indoor caged trapping showed that the numbers of adults trapped by the formulations cis-3-hexenyl acetate+(Z)-9-octadecene acetate, 1-hexanol+(Z)-9-octadecene acetate and dibutyl phthalate+methyl glycate were significantly higher than that of the control (paraffine oil). The formulation cis-3-hexenyl acetate+(Z)-9-octadecene acetate caused the highest selective response rate (74.06%) in H. oblita adults, while the formulations 1-hexanol+(Z)-9-octadecene acetate and dibutyl phthalate+methyl glycate caused the selective response rates of 65.89% and 64.25%, respectively. The selective response rates in H. oblita adults caused by the three formulations, however, showed no significant difference. 【Conclusion】 The binary attractant formulations cis-3-hexenyl acetate+(Z)-9-octadecene acetate, 1-hexanol+(Z)-9-octadecene acetate, and dibutyl phthalate+methyl glycate show strong attractiveness to H. oblita adults and can be used as effective attractants to ecologically control this insect.
    Analysis of alkaloid components in the soil from the nest of the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae)
    LI Xiao-Ling, CHEN Li, FANG Shou-Guo
    2020, 63(4):  494-501.  doi:10.16380/j.kcxb.2020.04.012
    Abstract ( 821 )   PDF (1588KB) ( 112 )   PDF(mobile) (1588KB) ( 8 )     
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     【Aim】 The red imported fire ant, Solenopsis invicta, inhabits the soil environment rich in bacteria and fungi. Although they are vulnerable to infection of bacterial and fungal diseases, fire ants with defensive and antibacterial venom alkaloids can survive in such soil environment. This study aims to establish an optimal extraction method of alkaloids from the soil of the red imported fire ant nest and then to quantify the major components of venom alkaloids. 【Methods】 In the recovery experiment, S. invicta venom was added to soil obtained 3 m away from S. invicta nests. Venom alkaloids were then extracted from soil using a filtration method. GC-FID was used for quantitative analysis of venom alkaloids, screening of the optimal extraction solvent, and determination of the optimal volume of triethylamine. The optimized method was used for quantitative analysis of venom alkaloids from the soil of ant nest. 【Results】 Among the five extraction solvents including n-hexane, dichloromethane, ethyl acetate, acetone and methanol, the recovery rate of alkaloids by n-hexane extraction was relatively higher. The best extraction efficiency was achieved by adding 1 mL or more triethylamine. Among the venom alkaloids in the soil of S. invicta nest, the content of trans-C15∶1 was the highest, followed by that 
    of trans-C13∶1. The content of total alkaloids in S. invicta nest soil was about 22 μg/g. 【Conclusion】 Triethylamine is very effective for extracting venom alkaloids from the soil of ant nests. The concentration of alkaloids in the soil of S. invicta nest is relatively high, which may have an important impact on the microbial community in the nest environment.
    Genetic diversity analysis of Geisha distinctissima (Fulgoroidea: Flatidae) in the Zhoushan Archipelago based on mitochondrial 16S rRNA gene 
    LI Kui, ZHOU Chuan-Jiang, LIANG Ai-Ping
    2020, 63(4):  502-511.  doi:10.16380/j.kcxb.2020.04.013
    Abstract ( 544 )   PDF (1994KB) ( 100 )   PDF(mobile) (1994KB) ( 13 )     
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    【Aim】 This study aims to reveal the impact of island isolation on the genetic diversity of Geisha distinctissima inhabiting in the Zhoushan Archipelago in East China. 【Methods】 Based on 16S rRNA gene fragments of 247 individuals from 15 populations of G. distinctissima in 11 islands and adjacent mainland obtained in this study, the population genetic diversity of G. distinctissima in this region was assessed. The phylogenetic analysis was conducted using Bayesian inference method and the haplotype network was constructed to resolve genetic structures among G. distinctissima populations. The demographic history of G. distinctissima populations was also evaluated by neutrality test, mismatch distribution analysis and Bayesian skyline plots (BSP). 【Results】 Both Bayesian phylogenetic analysis and haplotype network showed that the G. distinctissima populations in the Zhoushan Archipelago did not develop distinct genetic structure. Moreover, the molecular analysis of variance (AMOVA) showed that genetic differentiation mainly occurred within population (68.26%), suggesting that G. distinctissima populations of this region are homogeneous in genetic diversity. No correlation was found between the haplotype and nucleotide diversity and the isolated time and distance of islands. In addition, the neutral test showed that both Tajima’s D and Fu’s Fs exhibited prominent negative values, and there was a single peak in mismatch distribution analysis with canonical unimodal format, suggesting that G. distinctissima populations in the Zhoushan Archipelago may suffer from population expansion events. The BSP analysis showed that the expansion events occurred between 0.5-3.5 thousand years ago (kya). 【Conclusion】 Island isolation might have not exerted visible impacts on the divergence of genetic diversity among G. distinctissima populations in the Zhoushan Archipelago and adjacent mainland.
    Determination of larval instars and the observation of head morphology and sensilla of the final instar larva of Callosobruchus chinensis (Coleoptera: Bruchidae)
    CUI Xiao-Lin, WANG Hong-Min, ZHANG Jing, ZHANG Xian-Hong, ZHENG Hai-Xia
    2020, 63(4):  512-522.  doi:10.16380/j.kcxb.2020.04.014
    Abstract ( 1056 )   PDF (7066KB) ( 173 )   PDF(mobile) (7066KB) ( 65 )     
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    【Aim】 This study aims to clarify the number of larval instars and to understand the types, morphology and distribution of sensilla on the final instar larval head of the adzuki bean beetle, Callosobruchus chinensis. 【Methods】 The body length, head capsule 
    width and mandible width of C. chinensis larvae were measured. Based on the frequency histograms, regression relationship and Dyar’s rule of the obtained data, the optimal morphological index for determining the larval instars of C. chinensis was determined. The obtained result was verified by Crosby growth rule and linear regression method. The morphology and sensilla on the head of the final instar larva of C. chinensis were observed under scanning electron microscope. 【Results】 The frequency histograms of the body length, head capsule width and mandible width of C. chinensis larvae showed four obvious peaks, and it is so inferred that C. chinensis larvae have four instars. The four instars had the body length range of 1.581-2.556, 2.406-3.381, 3.381-4.281 and 4.206-4.881 mm, the head capsule width range of 0.444-0.689, 0.654-0.934, 0.934-1.179 and 1.144-1.389 mm, and the mandible width range of 0.080-0.256, 0.234-0.344, 0.322-0.542 and 0.542-0.652 mm, respectively. The body length, head capsule width and mandible width are in accordance with Dyar’s rule and Crosby growth rule, and show obvious linear relationship. Therefore, the body length, head capsule width and mandible width can be used as important indexes for the division of larval instars of C. chinensis. The Crosby ratio of head capsule width is smaller than those of body length and mandible width, and the correlation coefficient between the logarithmic value of head capsule width and body length and larval instar is higher than that between mandible width and larval instar, so the head capsule width can be used as the optimal index for the division of larval instars. Seven types of sensilla including sensillum basiconicum, sensillum trichodeum, sensillum lageniform, sensillum chaeticum, sensillum placodeum, sensillum styloconicum and sensillum ampullaceum were observed on the head and are mainly located on the antennae, maxillary palp, labrum and mandible. 【Conclusion】 The morphological indexes of the division of larval instars and the observation of head morphology and of the C. chinensis provide a theoretical basis for the study of behavior and integrated control.
    CONTENTS
    Contents of Vol. 63 Issue 4
    2020, 63(4):  522-522. 
    Abstract ( 362 )   PDF (491KB) ( 45 )   PDF(mobile) (491KB) ( 4 )     
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