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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 July 2018, Volume 61 Issue 7
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  • RESEARCH PAPERS
    cDNA cloning and expression profiling of small heat shock protein genes and their response to temperature stress in Monochamus alternatus (Coleoptera: Cerambycidae)
    LI Hui, HE Xuan-Yu, TAO Rong, CHEN Hong-Jian, GONG Xin-Yue, LI Shou-Yin, HAO De-Jun
    2018, 61(7):  749-760.  doi:10.16380/j.kcxb.2018.07.001
    Abstract ( 804 )   PDF (4018KB) ( 423 )     
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    【Aim】 Monochamus alternatus, an important stem borer in pine forests in southern China, is a major vector of pine wilt disease. It has a wide range of distribution and strong resistance to temperature stress. The study aims to better understand the molecular mechanism of resistance to temperature stress in M. alternatus. 【Methods】 The full-length cDNA encoding small heat shock protein (sHSP) was cloned
    from M. alternatus by RT-PCR and RACE techniques. The sequence characteristics of this sHSP were analyzed by bioinformatics methods. The expression patterns of this gene in different developmental stages, various tissues of the 4th instar larvae and the 4th instar larvae stressed under different low and high temperatures were detected by qPCR, and the stability of the reference genes at different temperatures was analyzed by geNorm, NormFinder and BestKeeper tools. 【Results】 The complete cDNA of the gene encoding sHSP was obtained from M. alternatus, and named MaltHSP21.20 (GenBank accession no.: MH091811). The complete cDNA (871 bp) encodes a protein of 187 amino acids, with a signal peptide of 18 amino acids in N-terminus, the molecular weight of 21.20 kD and the theoretical pI of 8.65. The domain prediction conforms to the characteristics of the sHSP family, containing 10 β-sheets and 7 β-sheets in the α-domain. Phylogenetic tree analysis showed that the sHSP sequence shares high homology with sHSP of Anoplophora glabripennis. The most stable reference gene was different identified by different methods, and assessed by three methods the most stable reference gene was RPL10. MaltHSP21.20 was expressed in all developmental stages of M. alternatus, with the highest expression level in diapause larvae, and moderate in egg and pupal stages. MaltHSP21.20 was expressed in different tissues of the 4th instar larvae, with the highest expression level in fat body. The expression of MaltHSP21.20 in the 4th instar larvae showed no response to low temperature, while was up-regulated significantly at 35℃, reached the maximum after exposure to 45℃ for 2 and 3 h, and down-regulated at 50℃. 【Conclusion】 RPL10 is a more stable reference gene under different temperature stress. Compared to other heat shock protein genes, MaltHSP21.20 is less sensitive to low temperature and presumably plays an important role in larval diapause during overwintering and the resistance to high temperature.
    Molecular cloning of a serine protease gene DdSP and its response to temperature stress in Galeruca daurica (Coleoptera: Chrysomelidae)
    DAN Yan-Min, ZHANG Yu, HUO Zhi-Jia, PANG Bao-Ping, SUN Xue-Tao
    2018, 61(7):  761-770.  doi:10.16380/j.kcxb.2018.07.002
    Abstract ( 854 )   PDF (4164KB) ( 250 )     
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    【Aim】 Serine protease (SP) is an important proteolytic enzyme, with serine as its active center. This study aims to clone a serine protease gene from Galeruca daurica and to analyze its expression levels in response to temperature stress so as to lay a foundation for further investigation on the regulation mechanisms of temperature tolerance and other physiological functions in G. daurica. 【Methods】 Based on the transcriptome data of the 2nd instar larvae of G. daurica, the full-length cDNA of the serine protease gene was cloned from G. daurica by RACE, and its sequence was subjected to bioinformatics analysis. Its expression profiles in the 2nd instar larvae of G. daurica exposed to different temperatures (-10, -5, 0, 5, 25, and 35℃) for 1 h and recovered at 25℃ for 30 min were detected by qPCR. 【Results】 A serine protease gene was cloned from G. daurica, and named GdSP (GenBank accession no.: MG797556). GdSP is 1 110 bp in length with an open reading frame (ORF) of 969 bp, encoding a protein of 322 amino acids with the predicted molecular weight of 35.41 kD and pI of 5.61. The encoded protein shares the typical structural features of serine proteases, with a transmembrane domain but no signal peptide. Homologous sequence alignment and phylogenetic analysis showed that GdSP has the highest amino acid sequence identity (30.53%) with Anoplophora glabripennis SP. qPCR results showed that the expression levels of GdSP had no significant difference in the 2nd instar larvae of G. daurica exposed to different temperatures whereas increased significantly after recovery from the low (except -10℃) and high temperature stresses. 【Conclusion】 Rapid cold-hardening has no significant effects on the expression of GdSP while recovery from cold shock elicits its up-regulated expression.
    Molecular cloning, expression profiling and binding characterization of a Minus-C odorant binding protein from the oriental fruit moth, Grapholita molesta (Lepidoptera: Tortricidae)
    CHEN Xiu-Lin, SU Li, CHEN Li-Hui, LI Yi-Ping, WU Jun-Xiang, LI Guang-Wei
    2018, 61(7):  771-783.  doi:10.16380/j.kcxb.2018.07.003
    Abstract ( 822 )   PDF (5573KB) ( 274 )     
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    【Aim】 This study aims to clone the Minus-C odorant binding protein (OBP) gene of the oriental fruit moth, Grapholita molesta, and to measure its expression profiles in different adult tissues and the binding affinities of its recombinant protein with different ligands, so as to clarify its olfactory functions. 【Methods】 Based on the next generation sequencing of the female adult antenna of G. molesta, the complete coding sequence of a Minus-C OBP gene was cloned by using RT-PCR. The expression levels of this gene in different adult tissues (antenna, head with antennae removed, thorax, abdomen, leg and wing) of G. molesta were measured by qPCR. The recombinant protein was expressed by prokaryotic expression system and the purified protein was verified by SDS-PAGE and Western blot. The binding affinities of the recombinant protein with 35 ligands were analyzed using fluorescence competitive binding assay. 【Results】 A Minus-C OBP gene was successfully cloned from G. molesta and named GmolOBP14 (GenBank accession no. MF066361). The cDNA sequence of GmolOBP14 contains an ORF of 411 bp that encodes 136 amino acids including four conserved cysteine residues, and the encoded protein belongs to Minus-C OBPs subfamily. GmolOBP14 was expressed in different tissues of male and female adults, and had significantly higher expression levels in male wing and female antenna than in other tissues. The purified recombinant GmolOBP14 (rGmolOBP14) displayed binding abilities with 16 of the 35 tested ligands, and had higher binding affinities to pear ester and lauraldehyde with the dissociation constant Ki values of 6.92 and 12.74 μmol/L, respectively. rGmolOBP14 had medium binding abilities to decanal, tetradecanal, (E)-3-hexene-1-ol, benzyl alcohol and butyl hexanoate with the Ki values of 25.54, 20.61, 24.35, 23.44, and 23.33 μmol/L, respectively. rGmolOBP14 showed no binding activities to sex pheromones, suggesting that this protein is not involved in the perception and recognition of sex pheromones. 【Conclusion】 Based on the expression profiles of GmolOBP14 and the binding affinities of its recombinant protein to ligands, it is speculated that GmolOBP14 not only selectively binds and transports volatiles of the host plant but also participates in other physiological processes except for olfaction.
    Gene expression patterns and activities of trehalases in Antheraea pernyi (Lepidoptera: Saturniidae) pupae during diapause and diapause termination
    WANG De-Yi, RU Yu-Tao, WANG Yong, MA Yue-Yue, NA Shuang, SUN Liang-Zhen, JIANG Yi-Ren, QIN Li
    2018, 61(7):  784-794.  doi:10.16380/j.kcxb.2018.07.004
    Abstract ( 673 )   PDF (4587KB) ( 258 )     
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     【Aim】 Gene expression patterns and enzyme activities of trehalases in Antheraea pernyi pupae during diapause and diapause termination were detected so as to elucidate the relationship between carbohydrate metabolism and diapause termination during diapause of this insect. 【Methods】 The trehalase genes were cloned from A. pernyi pupa using RT-PCR technology and subjected to bioinformatics analysis. Their expression patterns in different tissues of A. pernyi pupae during diapause termination after exposure to long photoperiod (17L∶7D) and diapause (the control group) were analyzed by semi-quantitative RT-PCR. The relative expression levels of trehalase genes in the fat body of A. pernyi pupae during diapause termination under long photoperiod were measured using qPCR, the trehalase activity in the fat body was detected using 3,5-dinitrosalicylic acid method and the trehalose content in the haemolymph was measured using antrone chromametry method. 【Results】 Three trehalase genes were cloned from A. pernyi, named ApTreh1A, ApTreh1B and ApTreh2 and deposited in GenBank under accession numbers KU977455, KU977456 and KU977457, respectively. Their open reading frames (ORFs) are 1 797, 1 635 and 1 932 bp in length, encoding 598, 544 and 643 amino acids, respectively. Homologous sequence alignment and phylogenetic analysis indicated that ApTreh1A and ApTreh1B are soluble trehalases (TrehS), and ApTreh2 is a membrane-bound trehalase (TrehM). Tissue-specific mRNA expression profiling using semi-quantitative RT-PCR showed that ApTreh2 had a wider distribution and higher expression level than ApTreh1. The qPCR results indicated that the expression levels of ApTreh1A and ApTreh1B in fat body at 21 d after exposure to long photoperiod were up-regulated and significantly higher than that of the control group (12L∶12D) (2- and 4.7-fold, respectively), while down-regulated at 28 and 35 d, and then up-regulated again at 42 d. The expression levels of ApTreh2 were up-regulated gradually, and reached the maximum (2.7-fold as high as that of the control group) at 28 d. At 42 d after exposure to long photoperiod, there was another expression peak (2.3-fold as high as that of the control group), and then down-regulated gradually. Trehalase activities in fat body increased gradually, reached the peak (about 18.5 U) at 21 d after exposure to long photoperiod, while declined to the lowest level (11.2 U) at 35 d, and increased slightly at 42 d, showing the same variation trend as the gene expression. The trehalose content in the haemolymph increased under long photoperiod and reached the maximum at 21 d, and was higher than that of the control during the whole developmental stage. 【Conclusion】 The results suggest that the expression of trehalase genes shows the same variation trend as the trehalase activities in the fat body and the trehalose content in the haemolymph in A. pernyi, suggesting that the expression response of trehalase genes plays a significant role in pupal diapause and diapause termination of A. pernyi.
    Cellular location of antisense oligonucleotide of snoRNA Bm-15 and its interference efficiency with Bm-15 in Spodoptera frugiperda Sf9 cells
    LI Xin-Mei, QIU Wu-Jie, CUI Bin, YANG Zong-Lin, SHEN Ya-Wen, LU Yi-Ping, HAN Yun-Chao, LI Dan-Dan
    2018, 61(7):  795-800.  doi:10.16380/j.kcxb.2018.07.005
    Abstract ( 728 )   PDF (1808KB) ( 208 )     
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    【Aim】 To study the interference efficiency of antisense oligonucleotide (ASO) with insect small nucleolar RNA (snoRNA) Bm-15, and to investigate the intracellular delivery of ASO in cells. 【Methods】 Spodoptera frugiperda Sf9 cells were transfected with Cy5-labeled, 2′-O ribosomal methylation and phosphorothioate-modified ASO of Bm-15 through liposome. Co-localization of Bm-15 ASO (labeled with Cy5) and lysosome as well as mitochondria was screened by immunofluorescence. The interference efficiency of ASO with snoRNA Bm-15 was analyzed by detecting the expression level of Bm-15 in Sf9 cells transfected with Bm-15 ASO using real-time PCR. 【Results】 The proportions of ASO fluorescence signals inundating the whole cell and at the cell edge were 34% and 66%, respectively, in the transfected Sf9 cells after 48 h transfection of Bm-15 ASO, suggesting that ASO might be delivered into different subcellular organelles. Further co-localization analysis showed that Bm-15 ASO was transported into lysosomes but not mitochondria. qPCR result showed that the expression level of Bm-15 decreased by 47% in Sf9 cells transfected with Bm-15 ASO. 【Conclusion】 ASO can not escape from the cellular endogenous degradation machinery even after various chemical modifications, and this effectively explains the low interference efficiency of ASO with target gene in some circumstances.
    Chemical modification of soluble trehalase from Helicoverpa armigera (Lepidoptera: Noctuiadae)
    AI Dong, Lin-Rong-Hua, Wang-Meng, Liang-Xiao-He, Yu-Cai-Hong
    2018, 61(7):  801-807.  doi:10.16380/j.kcxb.2018.07.006
    Abstract ( 693 )   PDF (1607KB) ( 194 )     
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    【Aim】 This study aims to explore the composition of amino acid residues in the active site of soluble trehalase from Helicoverpa armigera by analyzing the effect of chemical modification on this enzyme activity. 【Methods】 Chemical modification method was used to investigate the effect of chemical modifier on the soluble trehalase activity in the 5th instar larvae of H. armigera. The number of amino acid residues in active center was obtained from the deactivation rate constant of the modification reaction. 【Results】 The soluble trehalase activity in the 5th instar larvae of H. armigera was reduced by 81.58% and 54.14% after chemical modification by 8 mmol/L carbodiimide (EDC) and 25 mmol/L phenylglyoxal (PG), respectively, indicating that the modification of carboxylic acid group and arginine residues can inhibit the soluble trehalase activity effectively. The treatment with the substrate trehalose prevented the loss of enzyme activity from the chemical modification. Kinetic studies on chemical modification showed that the active site of soluble trehalase includes one carboxylic acid group and two arginine residues. 【Conclusion】 These results indicate that two carboxylic amino acids, i.e., glutamic acid and aspartic acid, are the vital residues of the active site of the soluble trehalase, and arginine is essential for the trehalase activity. These results provide theoretical support for the development of new pesticides.
    Change of carbohydrate, protein and lipid contents in Galeruca daurica (Coleoptera: Chrysomelidae) adults during oversummering
    CHEN Long, ZHOU Xiao-Rong, GAO Li-Jun, TAN Yao, PANG Bao-Ping
    2018, 61(7):  808-814.  doi:10.16380/j.kcxb.2018.07.007
    Abstract ( 618 )   PDF (1340KB) ( 247 )     
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    【Aim】 This study aims to clarify the characteristics of main physiological and biochemical change in Galeruca daurica adults at different oversummering stages so as to lay a foundation for revealing the oversummering mechanism. 【Methods】 The contents of total sugar, trehalose, glycogen, lipid and water in G. daurica adults at different oversummering stages (pre-oversummering, during oversummering and post-oversummering) were determined by anthrone-sulfuric acid and methanol-chloroform methods, respectively, and the total protein content was detected by Coomassie brilliant blue G-250 method. 【Results】 The contents of total sugar, water and total protein in G. daurica adults were significantly higher at the pre-oversummering stage (26.81 μg/mg, 77.47% and 63.17 μg/mg, respectively) and post-oversummering stage (26.41-26.85 μg/mg, 75.29%-76.65% and 59.53-64.93 μg/mg, respectively) than during oversummering (18.77-21.14 μg/mg, 61.50%-67.20% and 39.82-52.54 μg/mg, respectively), whereas the change trend of glycogen contents was the opposite, being 8.43 μg/mg at the pre-oversummering stage, 5.91-6.14 μg/mg at the post-oversummering stage and 10.18-11.58 μg/mg during oversummering, respectively, and the content of lipid was significantly less at the post-summering stage (11.48%-11.65%) than at the pre-oversummering stage (42.48%) and during oversummering (36.05%-64.79%). The contents of lipid and total protein decreased gradually in G. daurica adults during oversummering, while the water, total sugar and glycogen contents showed no obvious change. The trehalose content in G. daurica adults at different oversummering stages fluctuated greatly from 2.66 μg/mg to 25.31 μg/mg. 【Conclusion】 Lipid and glycogen are the main energy materials of G. daurica adults during oversummering.
    Development of SSR primers for Simulium (Eusimulium) angustipes (Diptera: Simuliidae) based on RNA-seq dataset
    GUO Huan, WANG Gang, ZHANG Shu-Tian, HUANG Min
    2018, 61(7):  815-824.  doi:10.16380/j.kcxb.2018.07.008
    Abstract ( 582 )   PDF (1693KB) ( 287 )     
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    【Aim】 Simulium (Eusimulium) angustipes is a bloodthirsty species that transmits poultry diseases. In this study, S. (E.) angustipes transcriptomes were sequenced using RNA-seq technology, and the SSRs were developed using transcriptome datasets, which may serve as reliable molecular markers for population genetics research of simuliids. 【Methods】 Transcriptome database of S. (E.) angustipes larvae collected from Baoji of Shaanxi and Altay of Xinjiang was constructed. The software MISA was used to explore all the microsatellite loci in the unigene database of S. (E.) angustipes. Primers were designed using software Primer Premier 5.0 and Oligo 6.7 from the SSR loci chosen randomly. After PCR procedure and electrophoresis detection, the primers with polymorphism for SSR were screened and analyzed using Cervus 3.0.7 and other bioinformatics softwares. Unigenes with polymorphic SSR loci were annotated using BlastX against Nr and Swiss-Prot databases. 【Results】 A total of 29 471 SSRs were identified in S. (E.) angustipes transcriptome. The most frequent repeat motifs were mononucleotide motifs (87.05%), followed by trinucleotide motifs (7.95%). Among all the 34 SSR motifs, (A/T)n was the most abundant mononucleotide motif (86.93%). SSR primers were synthesized, and 15 primers were amplified successfully, of which 12 loci were polymorphic. BlastX results indicated that seven SSR loci were identified from the annotated genes. 【Conclusion】 Based on RNA-seq sequencing technology, we can better realize the development of SSRs for S. (E.) angustipes, which is of great significance to the study of population genetics of this group.
    Ultrastructure of waxy glands and waxy secretions in nymphs of Carsidara limbata (Hemiptera: Carsidarinae)
    LI Jia-Le, REN Li-Li, LUO You-Qing
    2018, 61(7):  825-834.  doi:10.16380/j.kcxb.2018.07.009
    Abstract ( 671 )   PDF (5223KB) ( 256 )     
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    【Aim】 Carsidara limbata is an insect pest that seriously damages Firmiana simplex. Observation and identification of the ultra-morphology of waxy secretions and waxy glands in C. limbata nymphs of different instars would provide a theoretical basis for the future studies on its growth and development. 【Methods】 The nymphal instars of C. limbata were determined by morphological characteristics, and the ultrastructure of waxy secretions and waxy glands in nymphs of different instars were observed using stereomicroscope and scanning electron microscopy (SEM). 【Results】 Waxy glands of C. limbata nymphs are divided into two types: one is wax-secreting pore, appearing on the integument since the 3rd instar nymph; the other is regular or irregular circular porous gland, rarely distributed in the 1st instar nymph. The gland amounts and types in late instar nymphs were more than those in early instars. Waxy secretions can be divided into four types, i.e., filamentous wax filament, hollow C-shaped wax filament, spring crimp wax filament, and hollow long wax filament. In addition, there is a circumferential hole ring at the end of the abdomen, and micro-thorn and various types of setae are distributed all over the dorsal and ventral surface of abdomen. 【Conclusion】 C. limbata nymph has four types of waxy secretions and two types of waxy glands. Their types and distribution are different among different nymphal instars. This study provides a reference for the study of waxy organs in Carsidaridae.
    Isolation and identification of intestinal bacteria and screening of cellulolytic bacteria in Proisotoma ananevae (Collembola: Isotomidae)
    WANG Li-Xiu, CHEN Wei, XIE Gui-Lin, ZHOU Liang
    2018, 61(7):  835-842.  doi:10.16380/j.kcxb.2018.07.010
    Abstract ( 711 )   PDF (2135KB) ( 373 )     
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    【Aim】 This study aims to determine the composition of intestinal bacteria in Proisotoma ananevae and to screen the cellulolytic bacteria. 【Methods】 The intestinal bacteria in P. ananevae adults were isolated and identified with traditional culturing method in combination with 16S rRNA sequencing. The cellulolytic bacteria were screened with carboxymethyl cellulose (CMC) plate media, and the cellulase activity was measured by 3,5-dinitrosalicylic acid (DNS) method under different pH conditions (pH 5.0-9.0). 【Results】 We isolated twenty bacterial strains from the intestinal tract of P. ananevae adults, which belong to 10 genera of three major phyla Firmicutes, Proteobacteria and Acinobacteria, i.e., Staphylococcus, Bacillus, Terribacillus, Advenella, Lysinibacillus, Arthrobacter, Enterobacter, Glutamicibacter, Leucobacter and Acinetobacter, and one unidentified bacterium. Among them, 10 strains were cellulolytic bacteria belonging to 6 genera of Firmicutes and Acinobacteria, i.e., Leucobacter, Bacillus, Terribacillus, Lysinibacillus, Arthrobacter and Glutamicibacter. The cellulase activities in all the cellulolytic strains were relatively higher under pH 7.0-9.0 and reached the maximum under pH 8.0. 【Conclusion】 The results suggest that the bacteria in the intestinal tract of P. ananevae adults have complex structure. The presence of a large number of cellulolytic strains in P. ananevae, the disintegrator in ecosystem, not only helps springtails use macromolecules to meet their own nutrition requirements, but also has important application value especially in feed production and industrial application.
    Temporal and spatial distribution of Wolbachia infection in the poinsettia thrips, Echinothrips americanus (Thysanoptera: Thripidae)
    ZHANG Xiao-Chen, FENG Ji-Nian
    2018, 61(7):  843-850.  doi:10.16380/j.kcxb.2018.07.011
    Abstract ( 684 )   PDF (1274KB) ( 281 )     
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    【Aim】 To demonstrate spatio-temporal infection dynamics of Wolbachia in the poinsettia thrips, Echinothrips americanus. 【Methods】 Specific primers were designed based on the sequence of Wolbachia surface protein gene (wsp) to construct the standard plasmid. The absolute real-time quantitative PCR was used to determine the copy number of wsp in different developmental stages (egg, nymph, prepupa, pupa and adult) and adult tissues (head, thorax, abdomen and terminal three segments of abdomen) of both sexes of the thrips. 【Results】 The copy number of Wolbachia increased with the development of E. americanus, and the copy number of Wolbachia in female adult was significantly higher than those in egg and nymphal stages. The copy numbers of Wolbachia in different adult tissues were different. In female adults the copy number of Wolbachia in abdomen was significantly higher than those in head, thorax and the terminal three segments of abdomen, while in male adults the copy numbers in thorax and abdomen were significantly higher than those in head and the terminal three segments of abdomen. Sex and tissue had significant interactions with the copy number of Wolbachia in E. americanus. 【Conclusion】 The results indicate that the infection of Wolbachia in E. americanus is affected not only by the developmental stage of host, but also by host sex and tissue. This study provides a theoretical basis for understanding the occurrence, establishment and spreading of this thrips.
    Bioefficacy of the combined application of entomopathogenic nematodes and thiamethoxam and its effects on the protective and detoxification enzyme activities in Bradysia odoriphaga (Diptera: Sciaridae) larvae
    WU Hai-Bin, GONG Qing-Tao, CHEN Zhen-Zhen, JIANG Li-Li, GONG Yi, XU Yong-Yu, SUN Rui-Hong
    2018, 61(7):  851-859.  doi:10.16380/j.kcxb.2018.07.012
    Abstract ( 662 )   PDF (3990KB) ( 262 )     
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    【Aim】 Pathogenic organisms or chemical pesticides can induce the defense responses of insects, and the physiological adaptation of insects might differ under the combined application of pathogenic organisms and chemical pesticides. This study aims to investigate the effects of combined application of entomopathogenic nematodes and thiamethoxam on Bradysia odoriphaga. 【Methods】 The LT50 value of the combined application of Steinernema feltiae SF-SN strain (Sf) (60 IJs/larva) and thiamethoxam (15 mg/L) against the 3rd instar larvae of B. odoriphaga was determined with filter paper culture method in the laboratory, and its effects on the protein content of enzyme solution and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferases (GSTs) and acetylcholinesterase (AChE) in B. odoriphaga larvae at different time after treatment were assayed by biochemical analysis. 【Results】 The LT50 value (41.05 h) of the combined application of Sf and thiamethoxam against the 3rd instar larvae of B. odoriphaga decreased by about 126.88 h and 31.77 h, respectively, as compared with those in treatments with the respective single agents with (Sf LT50: 167.93 h) and thiamethoxam (LT50: 72.82 h). During 24-72 h after treatment, the corrected mortality rates of B. odoriphaga larvae in the combined treatment group were significantly higher than those in treatments with the respective single agent, and reached the peak (96.61%) at 72 h. The protein contents of enzyme solution in B. odoriphaga larvae in the combined treatment group at 12, 24 and 36 h after treatment increased by 13.88%, 46.87% and 57.99%, respectively, as compared with the control group, and were significantly higher than those in the control group, Sf treatment group and thiamethoxam treatment group. The activities of SOD, CAT, AChE and GTSs in larvae in the combined treatment group decreased by 47.48%, 28.73%, 71.04% and 29.97% at 24 h after treatment, and by 46.34%, 4222%, 58.37% and 11.87% at 36 h, respectively, as compared with the control. The activities of the four enzymes in the combined treatment group were significantly lower than those in the control group, Sf treatment group and thiamethoxam treatment group at 24 h and 36 h after treatment. 【Conclusion】 The LT50 value of the combined application of Sf and thiamethoxam against the 3rd instar larvae of B. odoriphaga is significantly lower than those in treatments with the respective single agent, and the combined treatment can significantly restrain the activities of SOD, CAT, AChE and GTSs in larvae.
    Effects of pest insect feeding and mechanical damage on the defensive enzyme activities in leaves at different parts of kidney bean plants
    YUE Wen-Bo, ZHI Jun-Rui, LIU Li, YE Mao, ZHANG Xiang-Qian, ZENG Guang-
    2018, 61(7):  860-870.  doi:10.16380/j.kcxb.2018.07.013
    Abstract ( 719 )   PDF (1059KB) ( 255 )     
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    【Aim】 This study aims to explore the systematic defense mechanism of bean (Phaseolus vulgaris) plant against different insect pests. 【Methods】 Central leaves of each plant of P. vulgaris were fed by Spodoptera litura, Tetranychus urticae, Frankliniella occidentalis, or pricked manually with an insect needle for 6, 24, 48, 72 and 96 h, respectively, while the upper and lower leaves of each plant were left untreated. The changes in the activities of peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) in the upper, central and lower leaves were determined. 【Results】 In the central leaves fed by the three insect species, the activities of POD, CAT and SOD changed significantly, and their changing trends varied with insect species. Compared with the control, the POD activity in central leaves fed by the three insect species increased firstly and then decreased to the level of the control after insect infestation. The POD activity reached the maximum at 24 h after T. urticae infestation, which was 4.6 times as high as the control. However, the POD activity in the central leaves increased obviously and reached the peak at 48 h after both mechanical damage and F. occidentalis infestation. The POD activity in the central leaves ingested by S. litura displayed a slowly increasing trend, and reached the maximum at 72 h after infestation. The changing trends of the CAT activity were different among mechanical damage and feeding of the three insect species. Mechanical damage induced the CAT activity obviously at 24 h after treatment, while all three insect pests caused changes of the CAT activity at earlier time, which rose significantly at 6 h and then changed in different modes with feeding time. In the central leaves, the SOD activity increased significantly only at 96 h after mechanical damage, while T. urticae infestation obviously induced the SOD activity after 24 h. Moreover, the SOD activities were significantly inhibited at 72 h in the leaves fed by S. litura or F. occidentalis. In the undamaged upper and lower leaves, the activities of POD, CAT and SOD also changed significantly after insect infestation or mechanical damage. The POD activities in undamaged upper leaves were inhibited at 96 h. However, the POD activities in lower leaves were induced to different levels. In both upper and lower undamaged leaves, the CAT activities were activated obviously at 24, 6, 6, and 24 h after mechanical damage, the infestation of S. litura, T. urticae and F. occidentalis, respectively. Mechanical damage, and S. litura and T. urticae infestation resulted in prominent increase in the SOD activity in undamaged upper and lower leaves at 96, 72 and 72 h, but F. occidentalis infestation led to the SOD activity being inhibited obviously at 48 and 72 h. 【Conclusion】 Infestation of S. litura, T. urticae and F. occidentalis can induce the activities of defensive enzymes (POD, CAT and SOD) significantly in both damaged central leaves and undamaged upper and lower leaves, which leads to systematic defensive reactions in bean plant, but the changing trends of the enzyme activities vary among treatments. These results indicate that the temporal and spatial effects of the defense are related to the species of insect pests.
    Biological characteristics of the solanum mealybug, Phenacoccus solani (Hemiptera: Pseudococcidae)
    ZHI Fu-Ying, HUANG Fang, HUANG Jun, LI Wei-Di, 吕Yao-Bin
    2018, 61(7):  871-876.  doi:10.16380/j.kcxb.2018.07.014
    Abstract ( 956 )   PDF (1780KB) ( 451 )     
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    【Aim】 The solanum mealybug, Phenacoccus solani (Hemiptera: Pseudococcidae), is a new record species in China, and supposed to be a great potential threat to agricultural production and ecological environment. This study aims to reveal the biological characteristics of P. solani. 【Methods】 The reproductive mode, developmental duration, fecundity and morphological characteristics of various developmental stages of P. solani on the host Solanum tuberosum were investigated under laboratory conditions (27±1℃, RH 70%±5% and a photoperiod of 12L∶12D). 【Results】 P. solani is a parthenogenetic, thelyotokous species, and no male individual could be found in the population. There are five stages (egg, 1st-3rd instar nymphs and adult female) in the life cycle. Eggs are laid in a scattering mode, and hatched within ca. 24 min. Female adults also produce some eggs that are unhatchable. The nymphal stage lasts 14-22 d and the total life span is 33-64 d. Adult female has strong fecundity, with the number of eggs laid per female ranging from 135 to 337 (244 on average). The main morphological characteristics of each developmental stage: egg, oblong, yellow and transparent in appearance, with one pair of reddish brown compound eyes; the 1st instar nymph, also yellow in color, and moves fast; the 2nd instar nymph, protuberances appear on the marginal surface of body; the 3rd instar nymph, dark yellow in color, its protuberances become visible, and caudal valve protrudent; adult female, covered with a thick layer of white waxy powder, protuberances become more visible, body color becomes darker, and legs dark red in color. 【Conclusion】 The main biological characteristics of P. solani were clarified from the aspects of reproductive mode, developmental duration, and fecundity. The results imply that P. solani is an important and potential dangerous insect pest.
    Morphological characteristics for instar identification of Aphis glycines (Hemiptera: Aphididae)
    LI Hui, LIU Xiao-Xia, ZHI Hai-Jian, LI Kai, ZHANG Qing-Wen, LI Zhen
    2018, 61(7):  877-884.  doi:10.16380/j.kcxb.2018.07.015
    Abstract ( 1034 )   PDF (2207KB) ( 369 )     
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     【Aim】 This study aims to accurately determine the instars of the soybean aphid, Aphis glycines based on morphological characteristics. 【Methods】 Eight morphological indices of the wingless and winged A. glycines, including body length, body width, head width, the number of antennal segments, antenna length, cornicle length, cauda length and hind tibia length, were measured under the ultrawide area 3D microscope. 【Results】 The results indicated that the morphological characteristics are different among various instars of both wingless and winged A. glycines. The hind tibia length and cauda length of the wingless individuals and the hind tibia length, body length, antenna length, cauda length of the winged individuals displayed either no or low overlap between adjacent instars and thus could be regarded as remarkable criteria to identify instars of both morphs. Additionally, the cauda shape could be regarded as the representative morphological characteristics to differentiate the nymph and adult, and the number of antennal segments could be regarded as the morphological characteristics to differentiate the 1st instar nymph, 2nd instar nymph and the other instars. 【Conclusion】 The instars of A. glycine can be accurately and quickly identified according to the hind tibia length and cauda length of the wingless individuals and the comprehensive analysis about the hind tibia length, body length, antenna length and cauda length of the winged individuals. In addition, such morphological indices as the number of antennal segments, shape of cauda, body width, cornicle length and wing pad development facilitate the instar identification of this insect.
    Contents of Vol. 61 Issue7
    2018, 61(7):  885-885. 
    Abstract ( 487 )   PDF (480KB) ( 128 )     
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