Acta Entomologica Sinica

Cloning and functional analysis of salivary protein gene Sm13498 of the grain aphid, Sitobion miscanthi (Hemiptera: Aphididae)

FU Yu, WANG Qian, ZHANG Yong, CHEN Ju-Lian

2021, 64(9): 1009-1019. doi:10.16380/j.kcxb.2021.09.001

Abstract ( 157 )

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【Aim】 The grain aphid, Sitobion miscanthi, is a dominant cereal aphid species in the major growing areas of wheat (Triticum aestivum) of China. Sm13498 is a salivary protein specifically expressed in the salivary glands of S. miscanthi. This study aims to investigate the potential role of the functionally unknown salivary protein Sm13498 of S. miscanthi in modulating plant defense. 【Methods】 Based on the sequencing data of the salivary gland transcriptome of S. miscanthi, the full-length cDNA sequence of Sm13498 gene was cloned by PCR and analyzed by bioinformatics. The expression levels of Sm13498 in apterous adults of S. miscanthi feeding on T. aestivum leaves for different time were determined by RT-qPCR. The secretion function of the signal peptide of Sm13498 was verified by yeast secretory system. The function of Sm13498 and its subcellular localization in Nicotiana benthamiana was examined using Agrobacterium tumefaciens-mediated transient expression technique. 【Results】 The full-length cDNA sequence of Sm13498 of S. miscanthi was cloned (GenBank accession no.: MW346655). Its open reading frame (ORF) is 783 bp in length, encoding 260 amino acids with the predicted molecular weight of 28.01 kD and amino acids 1-22 predicted to be N-terminal signal peptide. Phylogenetic analysis showed that Sm13498 was most closely related to LOC100159087 precursor, an uncharacterized protein of Acyrthosiphon pisum, deposited in GenBank under the accession no. NP_0013135481, sharing 71.7% amino acid sequence identity. The RT-qPCR results revealed that the expression level of Sm13498 reached the peak in apterous adults of S. miscanthi feeding on wheat leaves for 12 h. Saccharomyces cerevisiae strain YTK12 containing the signal peptide fragment of Sm13498 grew normally on the YPRAA medium in the yeast secretion system, and catalyzed the conversion of colorless 2,3,5-triphenyltetrazolium chloride (TTC) to insoluble dark-red-colored triphenylformazan (TTF), confirming the secretion activity of the predicted signal peptide. The transiently expressed Sm13498 in N. benthamiana mediated by A. tumefaciens could suppress the programmed cell death induced by Bcl-2-associated X protein (BAX) and pathogen elicitor INF1. Subcellular localization results indicated that the fusion protein Sm13498-GFP was localized in the cytomembrane of N. benthamiana leaves. 【Conclusion】 The results suggest that the salivary protein Sm13498 of S. miscanthi may be involved in the suppression of plant defense responses. This study lays a foundation for identifying the salivary effectors of S. miscanthi and understanding the high adaptability of wheat aphids to wheat varieties.

Analysis of the transcriptomes of Galeruca daurica (Coleoptera: Chrysomelidae) adults at different summer diapause stages (In English)

LI Yan-Yan, CHEN Long, LI Ling, TAN Yao, PANG Bao-Ping

2021, 64(9): 1020-1030. doi:10.16380/j.kcxb.2021.09.002

Abstract ( 49 )

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【Aim】 This study aims to explore the crucial genes and metabolic pathways involved in obligatory summer diapause in Galeruca daurica, a new pest with great outbreak in the Inner Mongolia grasslands, northern China. 【Methods】 Using RNA-Seq, we performed sequencing, transcriptional profiling and functional prediction for G. daurica adults at different summer diapause stages, i.e. pre-diapause (PD), diapause (D) and post-iapause (TD), and screened differentially expressed genes (DEGs) at different summer diapause stages based on the RNA-Seq data. The expression levels of ten DEGs screened based on the RNA-Seq data were verified by qPCR. 【Results】 A total of 202 770 198 clean reads from nine libraries were filtered, and 12 078 060 transcripts were assembled into 82 292 unigenes with an average length of 783.59 bp and a N50 of 1 545 bp. The 2 395 (2 119 up-regulated and 277 down-regulated) and 62 (59 up-regulated and 3 down-regulated) DEGs were identified in the D vs PD and TD vs D omparison groups, respectively. The KEGG analysis revealed that the glycolysis/gluconeogenesis and fatty acid biosynthesis pathways were significantly enriched in the D vs PD and TD vs D comparison groups, respectively. Additionally, many DEGs related to the Ca²⁺ signaling were differentially expressed during diapause. Finally, the expressional analysis result by qPCR for ten DEGs showed a high consistency between qPCR and RNA-Seq results. 【Conclusion】 The glycolysis/gluconeogenesis, fatty acid biosynthesis, and Ca²⁺signaling pathways may play an important role in diapause regulation of G. daurica. This study establishes a foundation for future studies on the molecular mechanism underlying obligatory summer diapause in G. daurica.

Discovery of the small cocoon mutant sc of Bombyx mori traveled onboard Tiangong-2 space laboratory in space and its gene mapping#br#

SHEN Guang-Sheng, SHEN Xing-Jia, ZHANG Long, ZHAO Qiao-Ling, GAO Meng-Jie, TANG Shun-Ming, HUANG Jing-Yi, CHEN Yan-Hua, JIANG Tao, ZHU Juan, WANG Mei-Xian

2021, 64(9): 1031-1040. doi:10.16380/j.kcxb.2021.09.003

Abstract ( 59 )

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【Aim】 The hybrid offspring of an alive female silkworm, Bombyx mori “Qiufeng× Baiyu” brought back to the earth after travelling onboard Tiangong-2 space laboratory in space for 33 d in 2016 was mated with the male moth of “Baiyu” strain reared on the earth ’s surface for producing eggs. Small cocoon individuals were found from the offspring, and then the normal cocoon strain TG and small cocoon mutant strain sc of ‘space silkworm’ were isolated and established. The objective of this study is to reveal the gene that leads to this mutant by analyzing its inherited characters and mapping the mutant gene. 【Methods】 Phenotypic analysis of TG and sc was performed. The sc, TG and normal large cocoon strain 0223V1 were served as experimental materials for preparation of (sc♀×0223V1♂) F₁ and its backcross types, (sc♀×0223V1♂) F₁♀×sc♂ and sc♀×(sc♀×0223V1♂) F₁♂, which were designated as BC1F and BC₁M, respectively. To screen polymorphic SSR markers, the genomic DNAs of sc, 0223V1 and F₁ were used as templates, and 10 SSR primers were randomly selected from each linkage group of B. mori for PCR amplification. By utilizing the characteristic of non-crossing-over between chromosomes in female B. mori, BC₁F population was used to identify the linkage group of sc gene. According to the SSR linkage map of B. mori, BC₁M population was used for gene mapping. 【Results】 Phenotypic analysis showed that the body size of sc larvae was smaller than that of TG larvae, and the cocoon weight of sc was about half that of TG. Genetic analysis showed that the mutant was controlled by a pair of recessive gene sc. Gene mapping results showed that sc is located between S2930-363 and S2930-289 SSR markers in the 3rd linkage group of the B. mori genome, with a physical distance of 684 kb containing 33 candidate genes. 【Conclusion】 This small cocoon mutant of space silkworm is controlled by a pair of recessive gene named sc located in the 3rd linkage group of the B. mori genome.

Effects of antimicrobial peptide HI-3 from Hermetia illucens (Diptera: Stratiomyidae) on the glutamine and glutamic acid metabolic pathway of human colon carcinoma HCT-8 cells

GAO Jia-Min, XU Xiao-Yan, HU Zi-Yuan, CHEN Ying-Dan, SUN Hong-Xia, YANG Yu-Feng, XIA Qiang

2021, 64(9): 1041-1049. doi:10.16380/j.kcxb.2021.09.004

Abstract ( 68 )

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【Aim】 To enrich the knowledge of the anticancer mechanism of antimicrobial peptide HI-3 extracted from Hermetia illucens by studying the effects of HI-3 on the amino acid metabolism of human colon carcinoma HCT-8 cells. 【Methods】 CCK-8 assay was used to determine the inhibition rates of different concentrations (80, 160, and 320 μg/mL) of antimicrobial peptide HI-3 on HCT-8 cells. The metabolites in HCT-8 cells were determined by GS-MS, and then the metabolic pathway with the most significant difference in amino acid contents and the target enzyme in this pathway were screened by pathway analysis based on R software. After the HCT-8 cells were treated with 320 μg/mL HI-3, the activity of the selected target enzyme glutaminase (GLS) was assayed by enzyme activity kit, its mRNA and protein expression levels were detected by RT-qPCR and Western blot, respectively, and the changes in the contents of important metabolites including glutamine (Gln), glutamic acid (Glu), glutathione (GSH), α-ketoglutaric acid (α-KG) and ATP involved in the glutamine and glutamic acid metabolic pathway in HCT-8 cells were detected by biochemical kits and ELISA kit. 【Results】 The inhibition rates of HCT-8 cells treated by HI-3 at the concentrations of 80, 160, and 320 μg/mL were 33.85% ±3.50%, 46.26%±0.90%, and 55.53%±1.70%, respectively, and the inhibition rates increased with the increase of the HI-3 concentration. HI-3 at the concentration of 320 μg/mL showed the greatest effects on the glutamine and glutamic acid pathway with the contents of amino acid metabolites in this pathway most significantly different from those in the negative control group (0 μg/mL HI-3). The activity of GLS (the target enzyme in this pathway) and the mRNA and protein expression levels of its gene GLS in the 320 μg/mL HI-3 treatment group were extremely significantly lower than those in the negative control group. Moreover, the contents of important metabolites in this pathway, including Gln, Glu, GSH, α-KG and ATP, in the 320 μg/mL HI-3 treatment group were also significantly reduced as compared with those in the negative control group. 【Conclusion】 Antimicrobial peptide HI-3 from H. illucens at the concentration of 320 μg/mL has the most significant effect on the glutamine and glutamic acid metabolic pathway in HCT-8 cells, and can significantly inhibit the proliferation of HCT-8 cells by blocking this pathway.

Molecular characterization and expression profiling of LY domain-containing trypsin genes in Anopheles sinensis (Diptera: Culicidae)#br#

ZHANG Xiao-Xiao, LEI Dan, LI Xiang-Ying, CHEN Bin

2021, 64(9): 1050-1060. doi:10.16380/j.kcxb.2021.09.005

Abstract ( 38 )

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【Aim】 To identify LY domain-containing trypsin (LY-trypsin) genes of Anopheles sinensis at the whole genome, and to explore their molecular characteristics, expression patterns and phylogentic relationships. 【Methods】 The amino acid sequences encoded by trypsin genes in An. gambiae, Aedes aegypti, Drosophila melanogaster, and Culex quinquefasciatus were downloaded from NCBI databases and used as queries to search for trypsin genes in An. sinensis genome using the local Blast program. LY-trypsin genes in An. sinensis were named based on domain characteristics and phylogenetic relationship. The structure, scaffold location, structural domain and phylogenetic relationships of LY-trypsin genes of An. sinensis, and their expression patterns at different developmental stages of An. sinensis, in different adult tissues of An. sinensis, and in female adults of An. sinensis before and after blood feeding were predicted using bioinformatics analysis. 【Results】 Twenty-seven LY-trypsin genes were identified in the whole genome of An. sinensis, while no LY-trypsin gene was identified in D. melanogaster, An. gambiae, C. quinquefasciatus, and A. aegypti. The 27 LY-trypsin genes of An. sinensis encode 329-1 125 amino acids, with the molecular weight of 36.8-125.5 kD, and pI of 4.73-8.94. Among them 20 LY-trypsin proteins have signal peptides, with their length ranging from 10 to 62 aa. The numbers of exons of the 27 LY-trypsin genes of An.sinensis range from one to five, and the length of introns ranges from 62 to 20 093 bp. The 27 LY-trypsin genes of An.sinensis are mapped on 11 scaffolds, their encoded proteins all have a conserved YWTD motif (LY motif), and the amino acid sequences encoded by 16 LY-trypsin genes of the 27 LY-trypsin genes have the active site containing the catalytic triad of serine, histidine and aspartic acid. Phylogenetic results showed that the 27 LY -trypsin genes of An. sinensis clustered into four branches. At different developmental stages, more than 50% of the LY-trypsin genes of An. sinensis showed similar expression patterns and were expressed at high levels during the larval stage. LY-trypsin genes were expressed in different adult tissues of An. sinensis. Only a few of LY-trypsin genes were expressed in female adults of An. sinensis before and after blood feeding without expression specificity. 【Conclusion】 In this study, LY-trypsin genes have been identified in the genome of An. sinensis for the first time, and the molecular characteristics and expression patterns of the LY-trypsin genes have been investigated. This study provides an information framework for the further study of LY-trypsin genes.

Identification and diversity analysis of bacteria in the venom glands of the fire ant, Solenopsis invicta, and two other ants (Hymenoptera: Formicidae)(In English)

YANG Fan, YU Jin-Yong, CHEN Si-Qi, NING Dong-Dong, Babar HASSAN, XU Yi-Juan

2021, 64(9): 1061-1069. doi:10.16380/j.kcxb.2021.09.006

Abstract ( 44 )

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【Aim】 The objective of this study is to assess the diversity of bacteria in the venom glands of the red imported fire ant, Solenopsis invicta, and to compare the bacterial communities in the venom glands with those of other two stinging ants, Solenopsis geminata and Diacamma rugosum. 【Methods】 16S rRNA V3-V4 regions of bacterial community of venom glands in S. invicta workers, alates and queens, S. geminata workers and D. ugosum workers were sequenced by using the Illumine Hiseq 2500 platform. Then, bioinformatic analysis was performed based on sequencing data. 【Results】 Proteobacteria were dominant in the venom glands of S. invicta workers, alates, and queens and S. geminata workers, while Firmicutes were abundant in the venom glands of D. rugosum workers. Tenericutes were more abundant in the venom glands of S. invicta queens than in the venom glands of workers and alates. The relative abundance of Pseudomonas in S. invicta queens was significantly higher than that in S. invicta alates and workers from Guangzhou. The relative abundance of Spiroplasma in the venom glands of S. geminata workers was significantly higher than that in D. rugosum workers. Microbial diversity analysis of venom glands of worker ants of Solenopsis species showed that the relative abundance of Bacillus and Lactococcus in S. invicta workers collected from Guangxi was significantly higher than that in S. invicta workers collected from Guangzhou. However, the relative abundance of Lactococcus in D. rugosum workers was significantly higher than that in workers of S. geminata from Guangxi. 【Conclusion】 The bacterial composition and diversity are different among the workers of three ant species, and among the three castes in red imported fire ant.

Gene cloning, expression and subcellular localization of a novel spore wall protein of Nosema ceranae (Microsporidia)

XIONG Liang, AO Tang-Yan, ZHANG Zhen, MA Zhen-Gang, ZHOU Ze-Yang

2021, 64(9): 1070-1079. doi:10.16380/j.kcxb.2021.09.007

Abstract ( 47 )

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【Aim】 The spore wall of Microsporidia plays an important role in the process of spore formation and host infection. The objective of this study is to identify a novel spore wall protein in Nosema ceranae, and to conduct the gene cloning and prokaryotic expression in order to clarify the subcellular localization of this protein. 【Methods】 Bioinformatics analysis of a novel spore wall protein AAJ76_1400036761 in N. ceranae was carried out using online software. The target DNA fragment was obtained by PCR and then cloned into the prokaryotic expression vector pCold II. The recombinant protein was induced by IPTG and purified by Ni²⁺ affinity chromatography. Polyclonal antibody was prepared by immunizing mice with the recombinant protein as antigen. The subcellular localization of the protein was analyzed by indirect immunofluorescence and immuno-colloidal gold labelling. Western blotting was used to detect the interaction between the protein and the chitin spore coat of N. ceranae. 【Results】 The gene sequence of AAJ76_1400036761 was obtained from Microsporidia DB. It is 681 bp in length encoding 226 amino acids with the predicted isoelectric point of 6.84 and molecular weight of 26.19 kD. The results of SDS-PAGE and Western blotting showed that the recombinant protein could be highly expressed in Escherichia coli Rosetta cells. Western blotting result revealed that the prepared polyclonal antibody could specifically recognize AAJ76_140003676 in the total proteins of N. ceranae, suggesting that this protein is expressed in mature spores of N. ceranae. The subcellular localization analysis showed that AAJ76_140003676 is located at the spore wall of N. ceranae. The recombinant protein AAJ76_1400036761 could bind with the chitin spore coat of N. ceranae. 【Conclusion】 AAJ76_140003676 is expressed in mature spores of N. ceranae. It is a novel spore wall protein of N. ceranae located at the spore wall. This study lays a foundation for further studying the biological functions of this protein.

Effects of knocking down neuropeptide F gene (npf) on the feeding, growth and reproduction of Ostrinia furnacalis (Lepidoptera: Pyralididae)

SHI Jian, WANG Yuan, LIANG Jia, DU Juan, ZHAO Zhang-Wu

2021, 64(9): 1080-1091. doi:10.16380/j.kcxb.2021.09.008

Abstract ( 37 )

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【Aim】 The neuropeptide F (NPF), a type of neuropeptides in invertebrates named based on its C-terminal phenylalanine (F), participates in the regulation of many physiological functions in insects such as feeding, biological rhythm, learning and memory. The objective of this study is to clarify the effects of NPF on the growth and development of the Asian corn borer, Ostrinia furnacalis, so as to provide an important basis for pest control. 【Methods】 A method based on the efficient synthesis of dsRNA targeting genes by engineering bacteria was used to efficiently and economically knock down npf. Low concentration (0.01%) and high concentration (0.02%) of dsNPF and dsGFP (the control) were separately fed to the early 1st, 3rd and 5th instar larvae of O. furnacalis until pupation. The average feeding amount, body weight, body length, survival rate and pupation rate of the 5th instar larvae, as well as the emergence rate of pupae and the number of eggs laid by adults were detected. Besides, the developmental duration at different larval instars and pupal stage and adult life span were also detected. 【Results】 When the early 1st, 3rd and 5th instar larvae of O. furnacalis were fed with 0.01% and 0.02% dsNPF, the feeding amount, body weight, body length, survival rate and pupation rate of the 5th instar larvae, the emergence rate of pupae and the number of eggs laid per female adult significantly decreased compared with the control fed with the corresponding concentrations of dsGFP. The developmental duration of larvae and pupae in the treatment groups were significantly prolonged, and the life span of adults was significantly shorter. The earlier the larval instar was treated with dsNPF, the greater the impact on development. Among them, the 1st instar larvae treated with 0.01% dsNPF and the 3rd instar larvae treated with 0.02% dsNPF had 90% of their individuals died in the pupal stage, and the 1st instar larvae treated with 0.02% dsNPF had 90% of their individuals died in the larval stage. 【Conclusion】 The results suggest that NPF plays a regulation role in the development and feeding of O. furnacalis, providing a basis for the exploration of new green pest control.

Oviposition preference of Serangium japonicum (Coleoptera: Coccinellidae) to eggplant varieties with different leaf trichome densities

MEI Wen-Juan, YAO Feng-Luan, LIN Shuo, DING Xue-Ling, ZHENG Yu, LU Xue-Song, HE Yu-Xian, WENG Qi-Yong

2021, 64(9): 1092-1103. doi:10.16380/j.kcxb.2021.09.009

Abstract ( 113 )

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【Aim】 Oviposition is vital for the survival and development of insect populations. Our previous study demonstrated that Serangium japonicum prefer to lay eggs on eggplant (Solanum melongena) leaves. This study aims to explore the oviposition preference of S. japonicum to eggplant varieties with different leaf trichome densities, so as to further clarify the mechanisms regarding to leaf trichome-related oviposition preference in S. japonicum. 【Methods】 Leaf discs and plants of four eggplant varieties (Heidaodi, Heiniu, Riyouchangzhizhuang and Luoxing) were provided for S. japonicum to determine the oviposition preference. The offspring performance including the growth and development, and adult fecundity, predation capability and attachment force of S. japonicum on leaves of each of the four eggplant varieties was tested. Microstructure of the abaxial leaf surface of the four eggplant varieties, the preference of S. japonicum female adults to leaf odours, the length and width of Bemisia tabaci eggs on eggplant leaves, and the cannibalism risk of S. japonicum eggs by its female adults were examined. 【Results】 S. japonicum preferred to lay eggs on Heidaodi, where the shortest offspring developmental duration (15.41±0.21 d) and the highest fecundity (877.44±15.27 eggs laid per female) were found. However, the proportion of S. japonicum eggs had no significant correlation with offspring performance (developmental duration, survival rate and adult body weight) and adult performance (fecundity and predation capability), but was significantly positively correlated with the density and length of leaf trichomes on the abaxial leaf surface (ALS). Furthermore, the proportion of S. japonicum eggs laid on leaf discs was significantly positively correlated with the attachment force of its female adults. The attachment force of S. japonicum female adults was positively correlated with leaf trichome density but had no significant correlation with adult performance. The leaf odour, prey quality, and cannibalism risk on the four eggplant varieties had no significant effects on the oviposition preference of S. japonicum. 【Conclusion】 The density of ALS leaf trichome and the attachment force of S. japonicum mediated by leaf trichomes play an important role in the oviposition preference of S. japonicum.

Influence of foliar fertilizers on the development and reproduction of the citrus red mite, Panonychus citri (Acari: Tetranychidae), and the growth of citrus seedlings (In English)

LIU Zhe, George Andrew Charles BEATTIE, CEN Yi-Jing, XU Chang-Bao

2021, 64(9): 1104-1111. doi:10.16380/j.kcxb.2021.09.010

Abstract ( 26 )

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【Aim】 The citrus red mite, Panonychus citri, is an important pest of citrus in China where foliar fertilizers are commonly used in citrus orchards. The objective of this research is to assess the influence of two fertilizers, urea and compound amino acid, on the development and reproduction of this mite, and on the growth of citrus seedlings. 【Methods】 Two foliar fertilizers, urea (0.50%) and compound amino acid (0.17%), were applied separately to potted citrus (Citrus reticulata Blanco cv. Shatangju) seedlings in the laboratory, and the seedlings sprayed with water were used as the control. The life-table parameters ［the net reproductive rate (R₀), mean generation time (T), intrinsic rate of increase (r_m), finite rate of increase (λ) and population trend index (I)］ of P. citri, the growth parameters (leaf length, width and area; stem length; plant height; number and length of new shoot leaves) of citrus seedlings and the nutrient (N, P and K) contents in leaves of citrus seedlings were investigated under controlled environment conditions. 【Results】 The duration of immature stages of P. citri was not influenced by the fertilizers, but the survival rate of deutonymphs on citrus seedlings applied with 0.50% urea (95.40%) was significantly higher than those on the control citrus seedlings (applied with water) (78.26%) and on citrus seedlings applied with 0.17% compound amino acid (75.61%). The fecundity of female mites reared on urea treated citrus seedlings (42.1/♀) was also significantly higher than that of females reared on the control citrus seedlings (33.1/♀). The longevity of females reared on compound amino acid treated citrus seedlings (19.5 d) was significantly longer than that of females reared on urea treated citrus seedlings (14.8 d) and the control citrus seedlings (14.5 d), and the longevity of males reared on compound amino acid treated citrus seedlings (17.6 d) was significantly longer than that of males reared on the control citrus seedlings (13.1 d). Overall, P. citri reared on urea treated citrus seedlings had the highest net reproduction rate (Ro) (17.88) and population trend index (I)(18.08), both significantly higher than that reared on the control citrus seedlings (10.08 and 11.17, respectively). Leaf growth (leaf length, width and area) of citrus seedlings was significantly promoted by both fertilizers. Both fertilizers also significantly increased N, P and K contents, and the ratio of N/K in leaves of citrus seedlings. 【Conclusion】 Urea and compound amino acid as foliar fertilizer both promote the growth of citrus seedlings. Compound amino acid should be recommended in preference to urea because spraying of urea increases P. citri populations in contrast to compound amino acid. However, P. citri population should be also monitored because that although compound amino acid does not facilitate population growth, it does increase the longevity of adult mites.

Electrophysiological responses of Holotrichia oblita (Coleoptera: Melolonthidae) to peach tree volatiles

ZHANG Nuo, CHEN Li, XIE Guang-Lin

2021, 64(9): 1112-1119. doi:10.16380/j.kcxb.2021.09.011

Abstract ( 56 )

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【Aim】 Holotrichia oblita is an economically important agricultural pest with a wide range of distribution and various host plant species. This study aims to identify peach tree volatiles that have the electrophysiological activity to the antennae of the female adults of H. oblita, and to further explore the effect of doses of the identified volatiles on the electrophysiological response in female and male antennae. 【Methods】 Volatiles from peach tree leaves were collected by dynamic headspace adsorption. The electrophysiologically active compounds from peach tree volatiles were identified by gas chromatography-electroantennographic detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS) techniques, and the responses of the antennae of female and male adults of H. oblita to the identified volatile compounds at doses of 0.01, 0.1, 1, 10 and 100 μg were tested with electroantennogram (EAG) technique. 【Results】 There were seven compounds in the peach tree volatiles that could trigger the electrophysiological reaction in the antennae of female adults of H. oblita, including Z-β-ocimene, Z-3-hexenyl acetate, Z-3-hexanol, nonanal, methyl salicylate and two unknown compounds. All the five peach tree volatile compounds with the electrophysiological activity to the antennae of female adults of H. oblita could trigger distinct EAG responses at all test doses in both female and male adults of H. oblita. The EAG responses of females and males to the same compound tended to increase with the increase of dose. The EAG response of females was significantly higher than that of males. 【Conclusion】 H. oblita adults generally show significant dose-dependent electroantennographic responses to Z-β-ocimene, Z-3-hexenyl acetate, Z-3-hexanol, nonanal, and methyl salicylate. There exists significant sexual difference in the EAG response. These compounds can be used for behavioral response and field trapping experiments to further confirm their attractiveness to H. oblita.

Light and dark adaptation of adult compound eyes of Spodoptera frugiperda (Lepidoptera: Noctuidae) and their transformation rate to light-adapted state under yellow light

JIANG Yue-Li, WU Yu-Qing, LI Tong, MIAO Jin, GONG Zhong-Jun, DUAN Yun, MEI Shi-Qiong, WANG Xue-Qin, LIU Qi-Hang

2021, 64(9): 1120-1126. doi:10.16380/j.kcxb.2021.09.012

Abstract ( 50 )

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【Aim】 The phototaxis of moths is directly related to the transformation of light and dark-adapted states of compound eyes. This study aims to clarify the relationship between light and transformation of light- and dark-adapted states of compound eyes of Spodoptera frugiperda. 【Methods】 Quickly taking photos at different time, the light- or dark-adapted state of compound eyes, light and dark-adapted transformation rate of S. frugiperda under light- or dark-adapted state and exposed to yellow light of different light intensities were statistically investigated. 【Results】 The maintenance rate of light-adapted state of compound eyes of S. frugiperda adults gradually increased as the light intensity increased after exposure to yellow light for 1 h under light-adapted state, those of males under yellow light at 0.1-0.5 and 4-6 lx were 67.77% (32.23% into dark-adapted and middle states) and 100%, respectively, while those of females under yellow light at 7-10 lx reached 98.90%. When S. frugiperda adults were exposed to yellow light for 3 h under light-adapted state, the maintenance rate of light-adapted state of compound eyes also gradually increased as the light intensity increased, those of males and females under yellow light at 0.1-0.5 lx were 50.00% and 32.23%, and those of females and males under yellow light at 7-10 lx were 90.00% and 100%, respectively. When S. frugiperda adults were exposed to yellow light at different intensities for 30 min under dark-adapted state, the compound eyes gradually transformed into light-adapted state, the light-adapted transformation rates of compound eyes of both females and males under yellow light at 0.1-0.5 lx were 93.33%, and those of females under yellow light at 0.6-0.9 lx and males under yellow light at 1-2 lx were 100%. 【Conclusion】 These results suggest that S. frugiperda adults have strong photosensitivity, and females are slightly more photosensitive than males.

Contents of Vol. 64 Issue 9

2021, 64(9): 1127-1127.

Abstract ( 24 )

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