【Aim】 This study aims to clarify the gene expression patterns of the odorant binding protein (OBP) OBP8 in Cylas formicarius and its ligand binding characteristics. 【Methods】 Based on the transcriptome data of C. formicarius adults, the odorant binding protein OBP8 gene was cloned from the antenna of C. formicarius adults and subjected to bioinformatical analysis. The expression patterns of this gene in adult antennae, mouthparts, wings and tarsi of C. formicarius were assayed by qPCR. Prokaryotic expression vector was constructed, and the recombinant protein was expressed and purified. The protein binding characteristics of the purified recombinant protein with 16 ligand compounds (one sex pheromone and 15 different plant volatiles) were assayed by fluorescence competitive binding assay. 【Results】 CforOBP8 (GenBank accession no.: MH549528) of C. formicarius was successfully cloned and sequenced. Its open reading frame is 414 bp in length, encoding a protein of 138 amino acids with the predicted molecular weight of 15.56 kD and the isoelectric point of 4.71. The N-terminal signal peptide of CforOBP8 consists of 21 amino acids. The mature protein possesses four conserved cysteines and can be classified into the Minus-C OBPs subfamily. The qPCR results showed that CforOBP8 was specifically expressed in the antenna of C. formicarius adults and slightly expressed in other tissues. SDS-PAGE analysis showed that the fusion protein was successfully expressed. The binding affinity assay of CforOBP8 to ligand compounds showed that CforOBP8 had the strongest binding affinity to sex pheromone (Z)-3-dodecen-1-yl(E)-2-butenoate with the dissociation constant (K_i) of 4.13 μmol/L, and a certain binding affinities to five plant volatiles including (Z)-3-hexen-1-ol acetate, limonene, nerol, nonanal and phenylacetaldehyde, with the Ki values of 7.54, 15.23, 16.31, 28.71 and 29.54 μmol/L, respectively. 【Conclusion】 CforOBP8 might be a pheromone binding protein of C. formicarius and play dual roles in the perception of sex pheromones and plant volatiles.

【Aim】 The study aims to explore the structure and distribution of odorant binding proteins of Harmonia axyridis, so as to provide a basis for further understanding the functions of odorant binding proteins in the olfactory system of H. axyridis. 【Methods】 Two odorant binding protein genes were cloned from H. axyridis, and their protein structures were analyzed by bioinformatics methods. The expression levels of the two genes in different developmental stages and adult tissues of H. axyridis were analyzed by qRT-PCR. 【Results】 Two odorant binding proteins genes of H.axyridis, HaxyOBP1 and HaxyOBP6 (GenBank accession numbers: MG757923 and MG757927, respectively), were successfully cloned and sequenced. The open reading frame of HaxyOBP1 is 447 bp in length. It encodes 148 amino acids with six conserved cysteines, indicating that HaxyOBP1 belongs to Classical OBPs subfamily. HaxyOBP1 was expressed in various developmental stages of H. axyridis and had the highest expression level in male adults. Tissue expression profiles showed that HaxyOBP1 had the highest expression level in the head of male adult. The open reading frame of HaxyOBP6 is 414 bp in length. It encodes 137 amino acids with four conserved cysteines, indicating that HaxyOBP6 belongs to Minus-C OBPs subfamily. The expression level of HaxyOBP6 in adults was higher than that in larvae, and the expression level in male adults was significantly higher than that in female adults. Tissue expression profiles showed that HaxyOBP6 had the highest expression levels in the head of male adult and the wing of female adult. 【Conclusion】 In this study, two odorant binding protein genes were cloned from H. axyridis. The expression profiles showed that HaxyOBP1 and HaxyOBP6 were highly expressed in the head and the wing of adults, respectively, suggesting that the OBPs of H. axyridis may also play important roles in non-olfactory tissues. The results of this study lay a foundation for further study on the structure and function of OBPs of H. axyridis.

 【Aim】 Tyrosine hydroxylase (TH) is a key enzyme of melanin biosynthesis and plays an important role in epidermal sclerotization. This study aims to obtain the cDNA sequence of TH gene of Helicoverpa armigera, and to analyze its molecular characteristics, expression pattern and function, so as to provide a foundation for further exploring its action mechanism. 【Methods】 The full-length cDNA sequence of TH gene was cloned from H. armigera by using bioinformatics and molecular cloning technique. The developmental expression pattern of this gene was assayed with qRT-PCR. The expression of TH gene in the 5th instar larva of H. armigera after treatment with 20E (20-hydroxyecdysone) (400 ng/individual) for different time and RNAi of ecdysone receptor gene (EcR) followed by 20E treatment (400 ng/individual) was analyzed by qRT-PCR, respectively. The TH acitivity in the fat body of H. armigera larvae after treatment with bio-stimulants bursicon (30 μg/mg tissue) and cAMP (200 ng/mg tissue) was determined by biochemical method. 【Results】 We cloned the full-length cDNA sequence of TH(GenBank accession no.: MF440319) from H. armigera, which is 2 270 bp in length with a 1 686 bp open reading frame encoding 561 amino acids. TH is ubiquitously expressed in all the examined developmental stages of H.armigera and relatively highly expressed in day-3 of egg stage, day-1 of the 2nd instar larval stage, 3rd-5th instar molting stages, prepupal stage and 1 day-old adult. In vitro treatment, the steroid hormone 20E (400 ng/individual) significantly up-regulated the transcription level of TH, but the 20E treatment after RNAi-mediated knockdown of 20E receptor gene EcR showed no obvious effect on the transcription of TH as compared with the control (injected with dsGFP only). Enzymatic activity assay demonstrated that both bursicon (30 μg/mg tissue) and cAMP (200 ng/mg tissue) led to significant increase of the TH activity. 【Conclusion】 20E is involved in the regulation of TH expression at the transcriptional level, and both bursicon and cAMP can promote the TH activity at the protein level.

【Aim】 To determine the type, morphology and distribution of antennal sensilla of female adults and larvae of Anopheles sinensis. 【Methods】 The morphological structure of the antennae of female adults and larvae of An. sinensis were observed under optical microscope, and the types, morphology and distribution of sensilla were observed under scanning electron microscope. 【Results】 The female antennae of An. sinensis adults are comprised of basal scape, pedicel, and a long flagellum with 13 flagellomeres. Four types of sensilla, including sensilla trichodea (sharp- and blunt-tipped), sensilla chaetica (large and small), sensilla basiconica or grooved pegs (types I and II) and sensilla coeloconica (large and small), were found on the female antennae of adults. Averagely the flagellum is covered with 1 135.67±86.75 sensilla. Among them, sensilla trichodea are the most numerous sensilla type found on the flagellum (662.00±6.22), followed by sensilla chaetica (294.67±33.35), sensilla basiconica (146.00±42.39) and sensilla coeloconica (36.50±5.90). Sensilla trichodea, sensilla chaetica and sensilla basiconica are distributed on each flagellomere, while the large sensilla coeloconica were not found on the 9th-11th flagellomeres, and the small sensilla coeloconica were only found on the distal tip of flagellomere 13. There is only one tubular flagellomere on larval antennae with a terminal sensory cone. Many pegs similar to the sensilla basiconica of female adults were found on the tubular flagellum, which were tentatively named as sensilla basiconica-like. Their numbers and sizes dramatically increase with the larval instar, and the grooves along the surfaces gradually become obvious, but their functions need to be further determined through ultrastructural and electrophysiological analysis. 【Conclusion】 In this study the morphological characteristics, type, number and distribution of antennal sensilla of An. sinensis larvae and female adults were observed and analyzed. The results provide a basis for further investigating the physiological functions of the sensilla of An. sinensis.

【Aim】 To reveal the gut microbial community structure and diversity in adults of the brown planthopper (BPH), Nilaparvata lugens. 【Methods】 The total gut DNA was extracted from the adult BPH. The V3-V4 region of the bacterial 16S rRNA gene and the fungal ITS2 fragments were sequenced by Illumina MiSeq (PE300), and then the number of operational taxonomic units (OTUs), species composition, abundance and alpha diversity of gut microbes were analyzed. The high-throughput sequencing data of four randomly selected gut microbes annotated were verified by qPCR. 【Results】 A total of 32 395 valid tags and 235 OTUs were obtained for gut bacteria of adult BPH, while the numbers of valid tags and OTUs for gut fungi were 24 986 and 128, respectively. The total OTUs of gut bacteria were annotated into 7 phyla, 15 classes, 26 orders, 45 families and 73 genera, while the fungal OTUs were annotated into 3 phyla, 9 classes, 12 orders, 15 families and 18 genera. At the phylum levels, the dominant gut bacteria were Proteobacteria, Bacteroidetes and Firmicutes, while the dominant gut fungi with the highest abundance belonged to Ascomycota. Acinetobacter, one indeterminate genus in Porphyromonadaceae and one indeterminate genus in Lachnospiraceae were dominated at the genus level in the bacterial communities, with the abundance of 36.37%, 17.22% and 15.01%, respectively. Fungi belonging to an indeterminate genus in Sordariomycetes were the most dominant, accounting for 95.77%. The alpha diversity analysis revealed that the number of observed species, Chao1 index, Shannon index and Simpson index were 235, 262.64, 3.90 and 0.62 for gut bacteria, and 128, 165.40, 0.91 and 0.75 for gut fungi, respectively. The qPCR results of four gut microbes confirmed that the highthroughput sequencing data had a high validity. 【Conclusion】 The results indicate that the bacteria and fungi are diverse in the gut of adult BPH. The results of this study not only lay the foundation for the further studies on the environmental adaption mechanisms of BPH from a microbial standpoint, but also facilitate the studies on the development of new technology for the biocontrol of BPH.

【Aim】 This study aims to clarify the toxicities of spinetoram and bifenazate to bumblebee Bombus terrestris, and to explore the effect of sublethal doses of these two pesticides on the activities of three detoxifying enzymes including acetylcholinesterase (AchE), glutathione-S-transferase (GST), and carboxylesterase (CarE). 【Methods】 The acute oral toxicities of 60 g a.i./L spinetoram and 43% bifenazate to the foragers of B. terrestris were measured by feeding method. The risk of the two insecticides to B. terrestris was assessed based on the hazard quotient (HQ) values for the ecological risk of insecticides to bees. The changes in the activities of AchE, GST and CarE in foragers of B. terrestris treated with the two pesticides at sublethal doses (LD₅₀and LD₈₀) were assayed. 【Results】 The LD₅₀values of 60 g a.i./L spinetoram and 43% bifenazate against foragers of B. terrestris at 48 h after oral exposure were 3.590 and 1 447 μg a.i. per bee, respectively. Spinetoram at the dose of 60 g a.i./L showed moderate toxicity to foragers of B. terrestris, while 43% bifenazate showed low toxicity. The HQ values of the two insecticides to foragers of B. terrestris were both below 50, suggesting that the two insecticides present low risk to this bumblebee species. The AchE activities in bees treated with LD₅₀ and LD₈₀ of spinetoram were significantly enhanced at 3 h (P<0.05), with a 1.45- and 1.23-fold increase as compared to the control group, respectively. Subsequently, the AchE activities in both the dose groups were inhibited after 24 h, and were significantly lower than that in the control group (P<0.05). The CarE activities in bees treated with LD₅₀ and LD₈₀ of spinetoram were also significantly higher in the first 3 h after treatment, being 1.24- and 1.53-fold higher than that in the control group, respectively, and then inhibited after 24 h. At 24 h after treatment, the CarE activity in the LD₅₀ dose group was significantly lower than that in the control group (P<0.05), but that in the LD₈₀ dose group showed no significant difference from that in the control group (P>0.05). The GST activities in bees treated with LD₅₀ and LD₈₀ of spinetoram were also activated at 3 h after treatment (P<0.05), with a 2.24- and 2-58fold increase as compared to the control group, respectively. At 24 h after treatment, the GST activities in both dose groups decreased, but were still significantly higher than that in the control groups (P<0.05). The AchE activities in bees were treated with LD₅₀ and LD₈₀ of 43% bifenazate within 3 h showed no significant differences from that in the control group (P>0.05), but reduced to 75% and 80% of that in the control group after 24 h, respectively (P＜0.05). The CarE activities in the both dose groups were inhibited after 3 h. The CarE activity in bees treated with LD₅₀ of bifenazate for 3 h was significantly lower than that in the control group (P<0.05), whereas that in bees treated with the LD₈₀ dosage showed no significant difference from that in the control group (P>0.05). The CarE activities in bees treated with LD₅₀ and LD₈₀ of bifenazate for 24 h were activated, and the LD₈₀ dose group had a significantly higher level of CarE activity than that in the control group (P<0.05), but the CarE activity in the LD₅₀ dose group showed no significant difference from that in the control group (P>0.05). The GST activities in bees treated with LD₅₀ of bifenazate increased at first (P<0.05), and then decreased. The GST activities in bees treated with LD₅₀ of bifenazate for 3 h and 24 h were 2.04- and 1.72-fold higher than that in the control group, respectively (P<0.05). The GST activity in the LD₈₀ dose group was not significantly different from that in the control group in the first 3 h (P>0.05), but was inhibited after 24 h and significantly lower than that in the control group (P<0.05). 【Conclusion】 The results demonstrate that spinetoram and bifenazate have low risk to the foragers of B. terrestris as judged by the HQ value. The safety of bifenazate to B. terrestris is higher, so it can be used in pollination period according to the recommended dosage and method. However, the excessive and long-term application of bifenazate may affect the physiology and behavior of bumblebees. The dosage and method of application of spinetoram during the pollination period need to be further explored.

【Aim】 This study aims to explore the mechanism of aphid feeding-induced salicylic acid (SA) in improving the insect resistance of potato (Solanum tuberosum) under potassium application, so as to provide the scientific basis for insect resistance in crops. 【Methods】 The endogenous contents of SA and proline, and the activities of phenylalanine ammonia lyase (PAL) and antioxidases including peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in potato leaves after potassium application (6 g potassium sulphate/plant), insect damage (aphid feeding, 5 adults of Myzus persicae/plant), potassium application plus aphid feeding, and spraying exogenous SA (20 mL/plant at the concentrations of 15, 30 and 45 μmol/L, respectively) were measured. 【Results】 The results showed that the SA contents in potato leaves in the treatment groups of potassium application, aphid feeding, and potassium application plus aphid feeding were 1.1, 1.3, and 1.5fold higher than that in the untreated control, respectively, and the PAL activities in these treatment groups were increased by 23.3%, 223% and 35.0% as compared to that in the untreated control, respectively. Both the SA content and PAL activity in potato leaves with potassium application plus aphid feeding were the highest among the above three treatments. Irrespective of potassium application, the SOD activities in potato leaves were increased significantly when the potato plants were sprayed with 15 μmol/L SA. After potassium application, the POD activities in potato leaves treated with SA at the doses of 15 and 45 μmol/L were 1.7- and 1.8-fold as high as those of the corresponding controls, respectively. Similarly, the CAT activities in potato leaves in potassium application group treated with SA at the doses of 15 and 30 μmol/L were 1.3- and 1.5-fold as high as those of the control groups, respectively. After 15 μmol/L exogenous SA was sprayed on potato leaves, the proline content in the treatment group (1.2 OD/g pro) was significantly higher than that in the control group (0.4 OD/g pro). 【Conclusion】 Both treatments of aphid feeding and potassium application plus aphid feeding significantly enhance the endogenous SA content and the PAL activity in potato leaves. Spraying exogenous SA at the dose of 15 μmol/L on potato leaves can significantly increase the activities of anoxidases including POD, SOD and CAT and the proline content in the potassium application group, indicating that 15 μmol/L SA is the most suitable treatment concentration. At this treatment concentration a positive interaction between applying potassium and SA happens. The results suggest that both aphid feeding and potassium application can increase the SA signal pathways and so enhance plant resistance to pest insects.

【Aim】 This study aims to ascertain the effect of drought during the root nourishing period of Chinese chives on the population dynamics of the chive gnat, Bradysia odoriphaga. 【Methods】 The number of adults of the F₁ generation of B. odoriphaga occurring in Chinese chives cultured in sandy soil and loamy soil under drought stress for 15, 20, 25 and 30 d was investigated by controlled irrigation to control the soil moisture, and the effect of drought stress on the population parameters of F₁ generation of B. odoriphaga was analyzed by two-sex life table method. 【Results】 The results showed that the occurrence of the adults of F₁ generation of B. odoriphaga fed on Chinese chives cultured in sandy soil and loamy soil were both restrained by drought. As the duration of drought stress increased, the number of B. odoriphaga adults obviously decreased. The number of B. odoriphaga adults was the lowest at 30 d after exposure to drought stress, and the number of B. odoriphaga adults emerged in loamy soil or sandy soil was only one and significantly different from those for other stress duration (15, 20 and 25 d). The duration of the 1st, 2nd, 3rd and 4th instar larva, the duration of immature stage, the preoviposition period and the total preoviposition period of adult female of the F₁ generation of B. odoriphaga exposed to drought stress for 30 d were significantly prolonged as compared with those in the control group, being prolonged by 0.82, 2.53, 2.82, 0.68, 6.32, 1.36 and 8.69 d, respectively, while the net reproductive rate (R₀), intrinsic rate of increase (r_m) and finite rate of increase (λ) were all significantly lower than those of the control, dropping by 32.38%, 37.50% and 5.13%, respectively, as compared with the control. 【Conclusion】 Drought treatment applied to Chinese chives during the root nourishing period can effectively alleviate the occurrence of B. odoriphaga.

【Aim】 This study aims to screen the optimal formulation and fermentation duration of sugar-acetic acid-ethanol-water solutions used to trap Agrotis ipsilon adults and to identify active volatile components from fermentation solutions. 【Methods】 Sucrose, acetic acid, ethanol and purified water were mixed together in different ratios, i.e., 3∶1∶3∶80, 3∶1∶3∶160, 3∶1∶6∶80 and 1∶1∶3∶80 (m/v/v/v) as solutions A, B, C and D, respectively, and sugar, white vinegar, liquor and tap water were mixed in the ratio of 6∶3∶1∶10 (m/v/v/v) as the solution E (the commonly used formulation), the taxis of A. ipsilon adults to the fermented sugar-acetic acid-ethanol-water solutions was tested using Y-tube olfactometer, and the components of volatile compounds from the solutions fermented for 1-15 d were analyzed with GC-MS. 【Results】 The taxis test results showed that the solution B showed significantly higher attractiveness to A. ipsilon adults than the solutions A, C, D and E, and the solution C followed. The solutions B and C fermented for 8 d showed significantly higher attractiveness to A. ipsilon adults than the unfermented solution and the solutions B and C fermented for other duration except 5 d and 7 d. In total, 41 compounds including 17 diolefines, 8 aldehydes, 2 ketones, 4 alcohols, 5 esters and 5 ethers were identified in the solution B fermented for 8 d. Moreover, the volatile components of the solution B fermented for 8 d were significantly different from those of the unfermented solution and the solution B fermented for 4 d and 12 d. 【Conclusion】 In this study we screened the optimal formulation (3∶1∶3∶160, m/v/v/v) of single component sugar-acetic acid-ethanol-water solution used to trap A. ipsilon adults and proved that their activities can be enhanced by fermentation with the optimal fermentation duration of 8 d.

【Aim】 Helionothrips mube has become a common pest on the taro (Colocasia esculenta) in recent years. This study aims to investigate the genetic differentiation among different geographic populations of H. mube in southwestern China. 【Methods】 The mitochondrial COI gene sequences of 132 individuals of H. mube from 21 geographic populations were obtained through Sanger sequencing, and the genetic diversity, genetic differentiation and molecular variance were analyzed by MEGA, DnaSP, Arlequin and Network software. 【Results】 Thirty-four variable sites were observed and 16 haplotypes were defined based on the 132 mitochondrial COI sequences (643 bp) from 21 geographic populations of H. mube, of which H1 had the highest frequency and the widest distribution. High levels of genetic diversity (Hd=0.712, Pi=0.00413, K=2.655) and genetic differentiation (Fst=0.3443), and low gene flow (Nm=0.96) were detected in the total population of H. mube. The analysis of molecular variance (AMOVA) indicated that the genetic differentiation of H. mube was mainly attributed to the intra-population. The Mantel test showed a positive correlation between the geographic distance and genetic distance. The neutral test showed that Tajima’s D value was significantly negative, but Fu’s Fs was not significant, and the mismatch distribution curve showed multiple peaks based on the whole datasets. The results of genetic distance among populations, haplotype phylogenetic tree and median-joining network all supported that the population genetic differentiation among the three populations of Chengdu, Sichuan (CHD), Changning, Yunnan (CHN) and Zunyi, Guizhou (ZY) were greater than that among other populations. 【Conclusion】 The H. mube populations in southwestern China are characterized by high genetic diversity and obvious genetic differentiation, the gene flow among populations might be affected by geographical distance, and the population of H. mube has not experienced recent expansion.

 【Aim】Scythropus yasumatsui, a major pest of Chinese jujube (Zizyphus jujuba) trees in northern China, is widely distributed in the main producing areas of jujube in provinces including Shaanxi, Shanxi, Hebei and Henan in China. This study aims to elucidate the genetic differentiation and gene exchange among S. yasumatsui populations in China. 【Methods】 Based on simple sequence repeats (SSRs) from the previously established transcriptome database, eight SSR loci were screened by PCR with fluorescence labeling and capillary electrophoresis genotyping, and the population genetic diversity was analyzed based on 308 individuals of 10 geographic populations of S. yasumatsui  from five provinces (Shanxi, Shaanxi, Ningxia, Hebei and Henan). 【Results】 All of the eight microsatellite loci had null alleles and deviated from HardyWeinberg equilibrium. Among the loci, the effective number of alleles (Ne) ranged from 2.113 to 8.016, the polymorphic information content (PIC) ranged from 0.561 to 0.908, and the expected heterozygosity (He) was between 0.476 and 0.865. The average index of genetic differentiation (Fst) among populations was 0.151, and the average gene flow (Nm) was 1.594. There was a significantly positive correlation between the genetic differentiation index and the geographic distance among different populations of S. yasumatsui (r=0.596, P=0.0035), and the phylogenetic trees based on Nei’s genetic distance and Cavalli-Sforza & Edwards genetic distance revealed that the 10 populations were all clustered into the three identical branches. 【Conclusion】 The results suggest that S. yasumatsui populations have a high level of genetic diversity, and there are a high genetic differentiation and a certain gene flow among different geographic populations. Geographic division is a critical factor which affects the genetic differentiation and gene exchange among S. yasumatsui populations.