【Aim】 This study aims to clarify the utilization of energy substances in flight muscles of Bactrocera dorsalis (Hendel). 【Methods】 The activities of five key enzymes related to energy metabolism in flight muscles of B. dorsalis, i.e, glyceraldehyde phosphate dehydrogenase (GAPDH), glycerol-3-phosphate dehydrogenase (GDH), lactate dehydrogenase (LDH), citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HOAD), were assayed and analyzed by tethered flight testing and biochemical methods in the laboratory. 【Results】 The activities of the five enzymes assayed changed with age (day-old) of B. dorsalis adults. The activities of GAPDH, GDH, LDH and CS peaked in the 4-day-old adults, while the HOAD activity peaked in the 20-day-old adults. During tethered flight, the activities of GAPDH, GDH and CS showed similar change trend, gradually increasing with tethered flight duration, while the activities of LDH and HOAD showed distinctively different change trend between male and female adults. The LDH activity in female adults during tethered flight was lower than that of female adults in resting state, while that in male adults was just the opposite except the 2 h tethered flight treatment. The HOAD activity in male adults fluctuated above the resting state level except the 24 h tethered flight treatment, while that in female adults fluctuated between the resting state level and below.【Conclusion】 Energy substrates in flight muscles of B. dorsalis include carbohydrate and lipid, but carbohydrate metabolism provides primary energy. During tethered flight, significantly different energy metabolisms exist between male and female adults. Both aerobic and anaerobic metabolisms are present in flight muscles of male adults, but only aerobic metabolism is present in female adults. Male adults can utilize lipids as energy substrate for flight, but female adults hardly utilize lipids as energy substrate for flight. Our study provided a scientific basis for further illuminating the mechanisms of the migratory behavior of B. dorsalis.

【Aim】 The brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is a serious rice pest in China and Southeast Asia. The occurrence and migration of N. lugens is thought to be related to temperature. This study was conducted to understand the expression patterns of heat shock protein genes (hsps) in the adaptation to temperature stress in N. lugens. 【Methods】 Female and male N. lugens adults were exposed to high temperature (30℃-40℃) for 1 h and 2 h, respectively. Real-time PCR was used to detect the expression of β-actin 1, β-actin 2, β-actin 3,28S rRNA, 18S rRNA and α-2-tubluin in their bodies. The most stable candidate reference gene was identified using geNorm and BestKeeper software. The expression levels of hsp70 and hsp90 genes in the treated N. lugensadults were measured using RT-qPCR. 【Results】 The most stable reference gene in both female and male adults of N. lugens after exposure to heat stress was β-actin 1. The expression levels of hsp70 after heat stress ranging from 30℃ to 40℃ in both female and male adults were not significantly different compared with those in the control group. The expression level of hsp 90 displayed significant up-regulation and reached the highest levels in female adults and male adults exposed to 40℃ and 38℃ for 2 h, respectively. 【Conclusions】β-actin 1 can be used as the reference gene for normalization of gene expression under high temperature stress in N. lugensadults. The expression of hsp 90 is induced by heat shock and the over-expression of hsp 90 might be involved in the enhancement of thermal tolerance in N. lugens adults.

【Aim】 PI3K signaling pathway plays important roles in many organisms involving in carbohydrate and lipid metabolism, cell and tissue growth, life span, etc. This study aims to study the function of phosphatidylinositol 3-kinase in the rice brown planthopper, Nilaparvata lugens. 【Methods】 The full-length cDNA of NlPIK3R1 gene was cloned by rapid-amplification of cDNA ends (RACE) according to its gene sequence information available in N. lugens transcriptome, and this gene encodes the p85α subunit of PI3K (PI3K p85α), with the GenBank accession number of KP635379. Then the real-time quantitative PCR and RNAi by feeding dsNlPIK3R1 to N. lugens adults were conducted to explore the expression pattern and the function of NlPIK3R1, respectively. 【Results】 The real-time quantitative PCR results showed that the NlPIK3R1 gene was slightly expressed in nymphs and male adults of N. lugens, but strongly expressed in gravid female adults. RNAi results showed that the expression of NlPIK3R1 was inhibited in the two dsNlPIK3R1 treatment groups (fed with 0.1 and 0.5 μg/μL dsNlPIK3R1, respectively), especially in the high concentration treatment group. Feeding of dsNlPIK3R1 led to the death of N. lugens adults. The survival rate of N. lugens adults in the high concentration treatment group significantly declined by 37.5% at 7 d after treatment, and showed significant differences (P<0.01) from those in the blank control group (87%) and the dsGFP group (76.67%). RNAi also resulted in a reduced eclosion rate and lighter body weight. 【Conclusion】 The results suggest that the NlPIK3R1 gene is very important for the survival and growth of N. lugens, and may serve as a potential target for controlling the brown planthopper.

【Aim】 Odorant binding proteins (OBPs) play an important role in olfactory recognition process. This study aims to explore the structure and function of odorant binding proteins of  Monochamus alternatus. 【Methods】 The cDNA and deduced amino acid sequences of MaltOBP2 and MaltOBP6 genes were analyzed by bioinformatics methods. The expression levels of the two genes in different tissues and developmental stages of  M. alternatus were detected by real-time RTPCR. Prokaryotic expression vector was constructed to express the recombinant proteins. 【Results】 We successfully cloned two odorant binding protein genes from M. alternatus, which were named as MaltOBP2 (GenBank accession no. KP120891) and MaltOBP6 (GenBank accession no. KP120892), with the opening reading frame of 402 bp and 408 bp in length, respectively. Their translated amino acid sequences contain four conserved cysteines, suggesting that they belong to the Minus-C OBP subfamily. MaltOBP2 and MaltOBP6 have six deduced α-helix regions, and the sites of α-helix regions are very similar between each other. However, the type and polarity of their putative ligand binding sites are completely different. Tissue expression profiles showed that MaltOBP2 and MaltOBP6 were differentially expressed in the head, antennae, maxillary (labial) palpi, abdominal apex and legs of M. alternatus adults, with the highest expression level in the head. The expression levels of MaltOBP2 and MaltOBP6 in antennae were not higher than those in other tissues. Developmental expression profiles showed that MaltOBP2 and MaltOBP6 had the highest expression level in the antennae of pupa and the head of larva, respectively. Prokaryotic expression vectors pET32a-MaltOBP2 and pET32a-MaltOBP6 were successfully constructed and the recombinant proteins were successfully expressed in Escherichia coli. Low temperature (16℃ and 20℃) induced higher levels of the expression of recombinant proteins in the supernatant, and long induction time (12 h) increased the expression of the protein. 【Conclusion】 In this study, the full-length cDNA of two Minus-C OBP genes were cloned from M. alternatus. Their encoded proteins have different physiological functions due to their different ligand binding sites. Expression profiling results suggested that these two OBP genes are not only involved in the olfactory recognition of M. alternatus, but also in other physiological functions such as taste sensing and chemical sensing. Our results lay the foundations for studying the structure and function of MaltOBP2 and MaltOBP6, and are also helpful to our understanding of chemical sensing in M. alternatus.

【Aim】 The objective of this study is to clone an odorant receptor gene from the diamondback moth, Plutella xylostella, characterize its expression profiles in different tissues and investigate its function. Our study provides a theoretical basis for understanding the mechanisms of host plant recognition of the diamondback moth. 【Methods】 The full-length cDNA sequence of PxylOR9 gene was obtained and cloned based on the transcriptome analysis of adult P. xylostella antennae. The relative expression levels of this gene in different tissues of both adult males and females were detected using semi-quantitative RTPCR. Two-electrode voltage clamp electrophysiological recording was used to test the response of Xenopus oocytes injected with PxylOR9 to 59 plant volatiles in vitro. 【Results】 Based on transcriptome sequencing and analysis in the preliminary study, several sequences of odorant receptors were predicted in P. xylostella. The full length cDNA of one of these genes, PxylOR9 (GenBank accession number: KP757898), was cloned in this study. Sequence analysis revealed that PxylOR9 has six transmembrane domains with an intracellular N-terminus, which is the typical structure of insect odorant receptors. Phylogenetic analysis showed that PxylOR9 is obviously different from sex pheromone receptors of several lepidopteran insects, but cluster together with their other general odorant receptors. The semi-quantitative RT-PCR results showed that the expression level of PxylOR9 was much higher in the antennae of both males and females than in other tissues. Voltage clamp electrophysiological recording indicated that PxylOR9 could only respond to the stimulation with β-ionone among the tested plant volatiles. 【Conclusion】 PxylOR9 of P. xylostella belongs to the general odorant receptor with a typical characteristic. PxylOR9 is highly expressed in adult antennae of P. xylostella. PxylOR9 can be activated by plant volatile β-ionone, implying that PxylOR9 may be involved in the recognition of P. xylostella to plants.

【Aim】 This study aims to isolate two sex determining genes (transformer and transformer 2), analyze their genomic DNA and cDNA structures and determine their expression profiles during different developmental stages and in adult tissues of the guava fruit fly, Bactrocera correcta. The findings will provide basic knowledge for further functional study of these two sex-determinating genes and the construction of the genetic sexing strain of the guava fruit fly. 【Methods】 The full-length cDNA sequences and their intronic seqences were isolated by PCR and RACE technique. The structure prediction, sequence alignment and phylogenetic analysis of the coding products of these two sex determining genes were performed by using different bioinformatics softwares. Based on the cDNA sequences of these two genes, specific primers were designed to investigate their developmental and tissue expression profiles by semi-quantitative RT-PCR. 【Results】 Two full-length cDNA sequences of transformer and transformer 2 were isolated from B. correcta and named as Bcotra and Bcotra2, respectively. Bcotra is transcribed sex-specifically: female transtranscript is 1 673 bp in length, which encodes a polypeptide of 413 amino acids (GenBank accession number KP712876), while male transcript is 2 025 bp in length, which encodes a truncated and non-functional polypeptide with in-frame stop codons on the two addtional exons that do not exist in female transcript (GenBank accession number KP712877). No sex-specific transtript was detected in Bcotra-2. Bcotra-2 is 1 458 bp in length, which encodes a polypeptide of 251 amino acids with the classic characteristics of RNA binding proteins (GenBank accession number KM658207). Bcotra-2  harbors 8 exons and 7 introns. Sequence alignment and phylogenetic analysis of the products coded by these two sex determining genes respectively with the known Tra and Tra-2 from other Dipteran insects revealed that Bcotra-2 shows higher homology than that of Bcotra with their respective homologues. The semi-quantitative RT-PCR result showed that Bcotra and Bcotra-2 was expressed in different developmental stages and various adult tissues of B. correcta. 【Conclusion】 In this study, the genomic and cDNA stuctures of two sex determining genes were identified in B. correcta. Both Bcotra and Bcotra-2 were detected during different developmental stages and in various adult tissues. The presence of Tra/Tra-2 binding sites, intronic splicing silencer sequence and RNA binding protein binding sites suggests that the regulation of sex development in B. correcta may rely on the interation between the post-translation of Bcotra and Bcotra-2. The fragment of 963 bp female-specific intron of Bcotra can be used for the vector construction to develop genetic sexing strains.

【Aim】 This study aims to uncover the antioxidant defense mechanisms in Spodoptera liturae larvae infected by the fungus Nomuraea rileyi.【Methods】 We measured the changes in the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the infected larvae of S. litura at different instars and compared the influences of different inoculation approaches including spraying method and dipping method on antioxidase activities in the infected larvae. 【Results】 The POD activity was not detected in both the infected larvae and the non-inoculated larvae (the control) of S. litura. The activities of SOD and CAT in the infected larvae were significantly higher than those in the control at the early stages of infection. However, the activities of SOD and CAT in the infected 2nd and 3rd instar larvae dropped sharply after reaching the peak at 16 h after inoculation. The antioxidase activities in the infected 4th and 5th instar larvae kept a high level for a long time and then turned lower than those of the control at 60-72 h after infection. The activities of SOD and CAT in the infected larvae which were inoculated with dipping and spraying methods were significantly higher than those of the control, and the dipping method had a greater effect on antioxidase activities than the spraying method in the 2nd and 3rd instar larvae, but there was no significant difference in the effects on the antioxidase activities in the 4th and 5th instar larvae between the two methods. 【Conclusion】 The antioxidase activities in S. litura larvae are greatly affected by the infection of N. rileyi. The activities of SOD and CAT increase first, and then decrease, and the trend of the change is closely related to the developmental stage of the larvae. The dipping method has a stronger influence on the SOD and CAT activities in the 2nd and 3rd instar larvae than on those in the 4th and 5th instar larvae when the body integument inoculation quantities are at the similar level.

【Aim】 Antheraea pernyi nucleopolyhedrovirus (AnpeNPV) produces epizootic outbreaks in populations of the oak silkworm A. pernyi. We conducted a comparative analysis among three AnpeNPV isolates to gain insight into the host/parasite interactions of this system at the molecular level. 【Methods】 We sequenced the genome of an AnpeNPV (AnpeNPV-H) isolated from Henan province, China and performed a comparative analysis with two previously sequenced isolates (AnpeNPV-L and AnpeNPV-Z) from Liaoning province. 【Results】 The AnpeNPV-H strain is 125 605 bp in length and contains 146 open reading frames of which 95 are identified as functional proteins and 51 are annotated as hypothetical proteins. The genetic arrangement (synteny) of the three strains is identical while six ORFs are truncated by stop codons in one or two of the isolates. There are more than 200 single nucleotide variations (SNVs) among the three AnpeNPV strains, 85% of which are found in coding regions. Fifty genes show amino acid changes, three of which (odv-e56, p94-like, and egt) have higher evolutionary rates of change (dN/dS>1), suggesting positive or purifying selection. Significant amino acid differences (changes in charge or hydrophobicity among isolates) are seen in envelope proteins, DNA polymerase, helicase and proteins involved in apoptosis and ecdysis. Finally, we show evidence of genetic recombination between AnpeNPV strains. 【Conclusion】 This study reveals the level of intraspecies variation among the strains examined and lends insight into host/virus interactions based on the dynamics of the A. pernyi nuclear polyhedrosis virus (AnpeNPV) genome.

【Aim】 The microbiota of insect guts plays important roles in food digestion, development and environmental suitability. This study aims to study the composition and antibiotic susceptibility of bacteria in the gut of the diamondback moth (DBM), Plutella xylostella (L.). 【Methods】 Bacteria from feces of the 3rd instar larvae of P. xylostella were isolated and identified by 16S rDNA analysis, and the antibiotic susceptibilities of these bacteria were tested by KirbyBauer disk diffusion method. 【Results】 There were six bacterial species of five genera in the gut of the 3rd instar larvae of P. xylostella, including Enterococcus mundtii, two species of Erwinia, Pantoea agglomerans, Paenibacillus sp. and Pseudomonas oryzihabitans, which were different from those known in the midgut of P. xylostella. E. mundtii was the most dominated bacterium. E. mundtii, E. persicina  and P. agglomerans were all resistant to penicillin, ampicillin, medemycin, clarithromycin and jiemycin, while presented similar susceptibilities to fosfomycin, vancomycin, doxycycline and some other antibiotics. 【Conclusion】 The bacterial microflora carried by P. xylostella have the characteristics of diversity and these bacteria have natural resistance to some antibiotics. Our study provides bacterial materials and foundation for the further study on functional bacteria and bacterial microflora in the gut of larval P.xylostella.

【Aim】 This study aims to clarify the effects of environmental colors on biological characteristics such as development and fecundity of Bradysia odoriphaga. 【Methods】 In laboratory conditions, the development and reproduction capability of B. odoriphaga were investigated in environments with different background color (black, brown, green, red and orange). 【Results】 The developmental duration of B. odoriphaga was the longest in orange environment (26.15 d), while was the shortest in black environment (22.35 d). The generation survival rate was the highest in black environment (43.88%) and lowest in orange environment (28.88%). There was no significant difference between sex ratios in environments with different background color. The adult longevity of both females and males was the longest in brown environment (2.06 d and 2.99 d, respectively) and shortest in orange environment (1.58 d and 2.57 d, respectively). The number of eggs laid per female was maximmal (62.99) in brown environment and the least (45.64) in orange environment. The indexes of population trend between different treatments (from high to low) were: black (15.90)>brown (15.07)>transparent contrast (12.93)>red (11.69)>green (11.67)>orange (8.50). 【Conclusion】 Environmental colors significantly influence the biological characteristics of B. odoriphaga. Black and brown environments facilitate its development and fecundity, while orange environment restrain both.

【Aim】 This study aims to obtain an overall knowledge of the species composition, occurrence and diversity alteration of fruit flies in Xingyi, Guizhou, southwestern China.【Methods】 The fruit flies were trapped using the methods of sex attractant, food attractant, and cultivation of infested melons to investigate and monitor the species and the number of individuals of fruit flies systemically from 2010 to 2011 in five different habitats in Xingyi, Guizhou, and all the collected data were analyzed with the related biodiversity indexes including Shannon’s diversity index. 【Results】 The dominant fruit fly species included Bactrocera dorsalis, B. cucurbitae, B. tau and B. scutellata in Xingyi, Guizhou, and the dominant species and similarity coefficient (0.33-0.89) varied with years and monitored sites. However, the annual population dynamics of the dominant fruit fly species was similar. The cluster analysis indicated that the relationship of the fruit fly species between two rural habitat orchards was the closest, while that between urban mixed orchards and other habitat orchards was the remotest. There were differences in the diversity indexes of the fruit fly species among different monitored sites, and the values of Simpson index, Shannon index and evenness index were 0.11-0.68, 0.28-1.25 and 0.18-0.62, respectively, in the two years monitored. 【Conclusion】 Fruit fly species richness are high in Xingyi, Guizhou. The occurrence of the fruit flies is related to local climate, host plant, ecological niche competition, etc. The numbers of species and individuals of trapped fruit flies are obviously higher in the habitat-similar mixed orchard than that in the mono-cultured orchard. The closer the flies to the urban, the earlier the occurrence period and the greater the amount of individuals. These results provide a scientific basis for control of fruit flies in this region.

【Aim】 Morphological identification of Aleyrodes proletella(L.) is limited by small size, high degree of similarity to related species and polymorphism. This study aims to develop a technique based on mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) gene sequence for the rapid identification of A. proletella, an invasive species newly found in mainland China. 【Methods】 The fragments of mtDNA COI gene of A. proletella and ten other whitefly species or cryptic species were amplified and sequenced using COI gene universal primers LCO-1490/HCO-2198. One pair of species-specific COI (SS-COI) primers, APZYJF and APZYJR, was designed. The target fragment amplified by the SS-COI primers (APZYJF/APZYJR) is 384 bp in length. The species specificity and sensitivity of the primer pair were tested. 【Results】 The species specificity of the primer pair was validated using ten other whitefly species and cryptic species, i.e., Trialeurodes vaporariorum (Westwood), Dialeurodes citri (Ashmead), Aleurodicus disperses (Russell), Paraleyrodes pseudonaranjae Martin, Bemisia afer (Priesner et Hosny), and five cryptic species of B. tabaci (Gennadius) (MED, Asia I, Asia II 1, Asia II 3 and China 1). All A. proletella specimens were successfully detected, and no cross reaction with other whitefly species or cryptic species was observed. The method was tested using individual male or female adult, individual 2nd instar, 3rd instar or red-eyed nymph, and even one grain of egg or single newly emerged 1st instar nymph, and proved to be applicable for all of these life stages. Sensitivity test results demonstrated that successful amplification could be obtained with the concentration of template DNA as low as 14.00±0.37 pg/μL, equal to 1/25 600 of a whole female adult of A. proletella. 【Conclusion】 The SS-COI method developed here provides a quick, simple and reliable molecular technique for the identification and monitoring of A. proletella, which would be useful in intercepting and blocking the further spreading of this new invasive whitefly species.