In insects, ecdysone signal transduction pathway is mediated by a cascade of transcription factors, and ecdysone receptor (EcR), Broad complex (BR-C) and E74A are believed to be the early response factors. To study the functions of these early transcription factors in Lepidoptera, double-stranded RNAs (dsRNAs) of these genes of Bombyx mori were synthesized in vitro and injected into the wandering larvae. Phenotype changes were observed and the expression of these and related genes were analyzed by quantitative real-time PCR (qPCR). Asynchronous pupation and eclosion, deviant wing and death of pupae and moths were observed after interference of BmEcR, BmBR-C and BmE74A. The qPCR results revealed that partial silence of BmEcR decreased the mRNA levels of BmE74A, BmE74B, BmHR3A and BmβFTZ-F1. Partial silence of BmE74A reduced the mRNA levels of BmEcR, BmBR-C, BmE74B, BmHR3A and BmβFTZ-F1, while partial silence of BmBR-C resulted in a significant decrease in the expression levels of all tested genes except for BmIAP. These results implied that BmBR-C may act at the earlier stage in ecdysone signal pathway and regulate the expression of other transcription factor genes as well as ecdysone receptor gene BmEcR in the silkworm.

 Insect cell line is one of the key components in baculovirus expression vector system and plays essential roles in baculoviral biology, identification of gene function, and expression of recombinant proteins, etc. In this study, a new cell line designated as Bm-Em-1 from the embryonic tissue of Bombyx mori (Lepidoptera: Bombycidae) strain Dazao was established， and this cell line had been subcultured over 40 passages on TNM-FH medium supplemented with 10% fetal bovine serum. Inverted microscope observation showed that this cell line has two major morphological types, i.e., round cells and spindle-shaped cells, and the chromosomes of the cell line were condensed into short rods and granule, typical of lepidopteran cell line. Random amplification of polymorphic DNA (RAPD) analysis showed that the DNA profile of the cell line Bm-Em-1 was similar with that of the embryonic tissue of B. mori, but different from that of BTI-Tn5B1-4 and Sf-9 cell lines. Growth curve analysis indicated that the population doubling time of the 28th passage cells was 82.2 h. Virus infection data proved that Bm-Em-1 was highly susceptible to B. mori nucleopolyhedrovirus (BmNPV) with the infection ratio up to 91.3% at 96 h post infection, but not susceptible to the Autographa californica multiple nucleopolyhedrovirus (AcMNPV). With such high infection rate by BmNPV, this cell line will be an ideal tool for BmNPV replication in vitro, BmNPV expression system and gene function study of B. mori.

 Surface coat proteins (SCPs) of Steinernema glaseri were proved to play important roles in defeating the host immune system. SCPs suppress insect immune response and promote infection of entomopathogenic nematodes. In this study, influences of different culture media on SCPs were investigated, which may provide useful information for further studying the immunosuppressive mechanisms of SCPs and the relationship between entomopathogenic nematodes and their hosts. Infective juveniles of S. glaseri were reared on an artificial medium and the last (5th) instar larvae of Galleria mellonella, respectively, and the SCPs from these nematodes were extracted with ethanol. SDS-PAGE and native-PAGE analysis of SCPs indicated that SCPs from S. glaseri nematodes reared on G. mellonella displayed more protein bands than those from the nematodes reared on the artificial medium. SCPs from S. glaseri nematodes reared on G. mellonella larvae had intensive lytic activity against hemocytes of G. mellonella both in vitro and in vivo, while SCPs from the nematodes reared on the artificial medium showed weak lytic activity. Moreover, hemocyte lytic SCPs were found to be inducible proteins. Variation of components and activity of SCPs from nematodes reared on different culture media demonstrates that the production of SCPs mainly depends on culture environments.

 The objective of this research is to analyze the diversity of Wolbachia in insects by using nested PCR-DGGE. Samples of Anagrus nilaparvatae, one of dominant egg parasitoids of rice planthoppers in Asian rice growth area, were collected from Hangzhou, China and the Philippines. After the total DNA was extracted, the 16S rDNA and wsp gene fragments of Wolbachia were amplified with nested PCR, and then analyzed using DGGE. The results showed that Wolbachia in A. nilaparvatae were sensitively and exactly detected based on 16S rDNA gene, and the dominant bacteria in A. nilaparvatae were Acinetobacter sp., Methylophilus sp., Acidovorax sp., Burkholderia sp. and Wolbachia sp. The analysis of wsp gene showed that Wolbachia in A. nilaparvatae from Hangzhou belongs to group A, sub-group Mors, and that from the Philippines belongs to group A, sub-group Dro. The results suggest that nested PCR-DGGE is an effective molecular tool for detecting the diversity of Wolbachia in Anagrus sp., and the 16S rDNA gene fragment is the optimal biomarker for Wolbachia detection, while the wsp gene is the optimal biomarker for Wolbachia species identification and classification.

 Bombus hypocrita (Hymenoptera: Apidae) is one of the dominant bumblebees in China, and is widely used as one of the most crucial pollinators in greenhouse due to easy mass-rearing, strong population and effective pollinating performance. However, it is often threatened by organophosphate and carbamate insecticides which are widely used in China, as these insecticides can inhibit the acetylcholinesterase (AChE) activity in insects. In order to avoid harm to bumblebees by these insecticides and improve the pollination technology and conservation of bumblebees, we optimized the reaction conditions to assay the AChE activity from the head of B. hypocrita, and evaluated the effect of six common organophosphate and carbamate insecticides on the AChE activity. The results showed that the optimal conditions are as follows: enzyme concentration 0.25 g protein/L, substrate concentration 0.8 mmol/L, pH 7.5, reaction temperature 40℃, and reaction time 5 min. The inhibition of six insecticides to AChE from B. hypocrita showed a dosage effect. The medium inhibition concentration (IC₅₀) values for chlorpyrifos, profenofos, triazophos, isoprocarb, bassa and propoxur are 0.39, 1.79, 0.42, 0.04, 0.43 and 0.63 mmol/L, respectively. The inhibitory effects of six insecticides to AChE from high to low are in the following order: isoprocarb> chlorpyrifos> triazophos> bassa> propoxur> profenofos, and B. hypocrita is more sensitive to isoprocarb than to the other five insecticides.

In order to determine insecticidal compounds from the methanol extracts of Tephrosia purpurea bark, the active compounds were isolated by activity-guided fractionation with column chromatography and identified based on NMR (nuclear magnetic resonance) and MS (mass spectrometry) data. Slide-dip method was performed to determine the insecticidal activities of each compound against Myzus persicae adults, and topical application was conducted to determine contact toxicity of each compound against the 3rd instar larvae of Pluttella xylostella. Ten known compounds were isolated and identified, i.e., 12a-hydroxyrotenone, 4′-hydroxyemoroidocarpan, pachyrrhizine, rotenone, 6-methoxycoumarin, (-)-edunol, obovatin, pongachin, 12-acetyelliptinol and 2-hydroxyrotenone. All these compounds exhibited insecticidal activity against the 4th instar larvae of Aedes albopictus with the LC₅₀ value being 12.5, 22.1, 25.0, 34.1, 43.4, 58.4, 121.9, 191.0, 219.8 and 250.0 mg/L, respectively at 24 h after treatment. Moreover, three compounds (4′-hydroxyemoroidocarpan, rotenone and 12a-hydroxyrotenone) exhibited insecticidal activity against M. persicae adults and the 3rd instar larvae of P. xylostella with their corresponding LC₅₀ values being 49.9, 1.9 and 0.9 mg/L against M. persicae adults, and with the LD₅₀ values being 49.8, 197.1 and 40.9 μg/individual against P. xylostella larvae, respectively. Eight known compounds, i.e., 4′-hydroxyemoroidocarpan, 2-hydroxyrotenone, 6-methoxycoumarin, pachyrrhizine, (-)-edunol, 12-acetyelliptinol, pongachin and obovatin, were isolated from T. purpurea bark for the first time. The elucidation of the structure of these phytochemicals and their insecticidal activity is important not only for understanding the insect-plant relationships, but also for assessing the potential of this plant as botanical insecticide to be explored and utilized.

 In order to clarify the sublethal effects of scopoletin on the experimental population of Tetranychus cinnabarinus (Boisduval), and provide the theoretical basis for the further development and application of scopoletin used as a plant-derived acaricide, we used the leaf disc bioassay to evaluate the effects of scopoletin at sublethal dosages on F₀ and F₁ populations. The results showed that the fecundity of female adults treated with scopoletin at three sublethal dosages (LC₄₀, LC₃₀ and LC₂₀) was increased by 73.82%, 186.97% and 70.18%, respectively, while the longevity, oviposition duration and frmale-to-male sex ratios were not affected. The duration of oviposition, larval and nymphal stages was not significantly different from that of the control (P>0.05), but the adult period and female longevity were shorter than those of the control. The F₁ generation displayed shortened oviposition duration, reduced fecundity and decreased the proportion of females when compared with the control. The net reproductive rate (R₀) dropped from 50.5976 to the lowest 33.9910, the mean generation time (T) and population doubling time (Dt) were all shorter than those of the control, and fitness defects appeared in all three treatment populations. The results indicate that scopoletin treatment at sublethal dosages can reduce the development and reproduction rates of T. cinnabarinus populations, and this provides positive evidence for application of scopoletin in pest management.

 To investigate the effects of larval density on the population growth of the beet webworm, Loxostege sticticalis, the larval duration and survival, pupal weight and adult fecundity were examined by rearing larvae at the densities of 1， 10， 20， 30 and 40 larvae/650 mL jar under laboratory conditions (22±1℃, RH 70%±5%, photoperiod 16L∶ 8D). The results showed that larval cuticular color, developmental duration and survival, pupal weight and adult fecundity of L. sticticalis were significantly affected by larval density. Larval cuticular melanization score became greater as the density increased, and the scores at the densities exceeding 10 larvae per jar were significantly higher than that at the density of one larva per jar (P<0.05). The developmental time of larva and pupa at the density of 20 larvae per jar was the shortest, while it was significantly prolonged as the larval density increased (P<0.05). The larval survival rate was the highest at the density of 10 larvae per jar, which was significantly higher than those at other densities (P<0.05). Pupal weight was the heaviest at the density of one larva per jar, and it was significantly reduced with the increase of larval density. The total fecundity per female and the proportion of mating individuals were the highest at the density of one larva and 20 larvae per jar, respectively, and they decreased as larval density increased. Adult oviposition duration was gradually shortened with the increase of larval density. The longevity of female and male was the longest at the density of 10 and 20 larvae per jar, respectively, while it was significantly shortened when larval density was too high. Life table analysis indicated that the population growth index was significantly affected by larval density, and it was the highest at the density of 10 larvae per jar, but lower at either higher or lower density. It is so concluded that larval density is one of the major factors influencing population growth in L. sticticalis.

 To gain insights into mechanisms of superparasitization in Meteorus pulchricornis (Wesmael), dual-choice tests were performed to observe preferences of the parasitoid between healthy and parasitized hosts, Prodenia litura (Fabricius) (healthy∶parasitized 2nd instar larvae=5∶5), as affected by parasitization experiences (three levels: no parasitization experience, parasitization once, superparasitization once) and interval-time (1-7 d) elapsed after single parasitization; a repeated measures design was exercised to observe oviposition stings during three successive visits to host patches of different quality as measured by the proportion of parasitized hosts (2, 5, and 8 parasitized hosts among 10 hosts, respectively) in a patch. The analysis results of preferences showed that the probability of superparasitization was significantly affected by parasitization experiences of parasitoids and time interval after single parasitization, and it was decreased with the time interval and parasitization experience. The Cox model was fitted to the discrimination time prior to oviposition, and the results indicated that the hazard of superparasitization diminished both with extending of the interval time after single parasitization and with the parasitoid experience of superparasitization. The trials on parasitization during visits to host-patches of different qualities showed that the number of oviposition stings increased with the quality of host patch. The results suggest that M. pulchricornis can discriminate not only parasitized hosts, but also host patches with single parasitized hosts.

Anoplophora glabripennis (Motsch.) is a main wood borer of willow, poplar and other deciduous hardwood trees in the northwestern China and North China. It is difficult to control this insect pest.  Dastarcus helophoroides (Fairmaire) is an important parasitoid of A. glabripennis and other cerambycids, and it has been used as a biological agent to control A. glabripennis in recent years in China. However, due to long life-span of D. helophoroides and its hosts, the evaluation of biological control effect of D. helophoroides remains a challenge. In order to appropriately evaluate the biological control effect of A. glabripennis by D. helophoroides, field experiments of three consecutive years were carried out to investigate the control effect after releasing the parasitoid. The sample area was located in Weiyang District, Xi’an City, northwestern China, where Salix babylonica L. was seriously infested with A. glabripennis. The parasitoid release site and two control sites were selected in this area, of which one control site (control site 1) was adjacent with the parasitoid release site, the other control site labeled as control site 2 was 1.5 km away from control site 1. All trees in the sample sites were painted and marked with numbers, so they could be continuously investigated in the following years. D. helophoroides adults were released in the releasing site on May 30, 2009. The results showed that the infested rates of A. glabripennis decreased both in the parasitoid release site and in the neighboring control site (control site 1) in the 3rd year. The average numbers of larval frass extruded hole per tree were decreased from 4.63 holes per tree and 5.06 holes per tree, respectively, in 2009 to 0.93 holes per tree and 0.87 holes per tree, respectively, in 2011. The infested rates of A. glabripennis in control site 2 were not significantly different between the first year (2009) and the third year (2011) （P＞0.05）, and the average number of frass holes per tree was 7.41 holes per tree in 2009 and 7.68 holes per tree in 2011, respectively. The results reveal that D. helophoroides can effectively control A. glabripennis and is a prospective insect natural enemy. Finally, methods for evaluating biological control effects of the longhorned beetles in fields were discussed based on the present study. For the longer life-cycle forest insect pests and their insect natural enemies, convincing evaluation results of biological control should be based on survey of longer period on treatments.

 From May to September 2004, choosing grasslands under different grazing pressure (i.e., ungrazed grassland, moderately grazed grassland and overgrazed grassland) as sampling plots in a typical steppe in Inner Mongolia, and collecting dung beetles by pitfall trap method, we analyzed the influences of grazing activity on dung beetle assemblages in order to clarify the effects of grazing activity on dung beetle assemblage. The results indicated that a total of 60 839 dung beetles belonging to 3 families, 5 genera and 24 species were captured. As grazing pressure increased, the changes of the number of individuals, biomass and species number of dung beetle assemblages were significantly different. Different dung beetles showed distinct sensitivity to grazing activity. All above indices of dung beetle assemblages had obviously seasonal characteristics. The Pearson corelation analysis showed that the individual number, biomass and species number of dung beetle assemblages as well as the numbers of individuals of Aphodius comma and Aphodius subterraneus had significant negative correlation with the increase of grazing pressure in spring. Moreover, the species number of dung beetle assemblage and the number of individuals of Ceratophyus polyceros had significant negative correlation with grazing pressure in summer. But in autumn, the biomass and species number of dung beete assemblages as well as the numbers of individuals of Ceratophyus fischeri, Gymnopleurus mopsus and Onthophagus gibbulus had significant positive correlation with the increase of grazing pressure. Based on body length, body weight and behavioral characteristics of dung beetles, four functional groups were classified. Grazing activity had greater influences on functional group Ⅲ and Ⅳ, whose body size were relative small. The results caculated with the IndVals method showed that C. fischeri, Aphodius scofa and A. subterraneus could be used as the indicator species to define grasslands under different grazing pressure in typical steppes in Innner Mongolia.

Our earlier study showed that Bemisia tabaci biotype Q in Shandong, China, originated from the Western Mediterranean rather than the Eastern Mediterranean. To uncover the invasion mechanism of biotype Q, we analyzed the genetic diversity of the Q-biotype populations from the Eastern Mediterranean using the mtCOI gene and 6 highly polymorphic microsatellite loci, and compared the diversity to that of the Western Mediterranean Q-biotype populations. The results showed that the genetic diversity indices of the populations from this region were as high as those from the Western Mediterranean, and did not exhibit a significant difference. However, genetic heterogeneity existed within the populations in the two regions. The comparison of the genetic structure of populations, in native ranges and with different invasiveness, will be helpful to further reveal the physiological and ecological mechanisms of the invading alien populations.

Bombus pyrosoma, a bumblebee species endemic to China, plays a vital role as one of the most abundant pollinators for many wild flowers and crops in North China. We report for the first time  the isolation and characterization of microsatellite markers within this population in order to support investigations into its genetic structure and evolution. Magnetic bead-based enrichment, PCR and bioinformatics were used to isolate microsatellite markers from B. pyrosoma. The species specificity of the isolated primers was confirmed through tests with seven other bumblebee species of the subgenus Melanobombus also known from China. Our results show that four dinucleotide probes have different hybridization rates to the microsatellite DNA sequence. The highest hybridization rate (82%) was obtained with the probe TC, the moderate hybridization rate (28%) with TG, and the lowest hybridization rates (0%) with AT and GC. For 31 polymorphic microsatellite loci isolated from B. pyrosoma, four types of microsatellite can be found by sequence analysis, i.e., 18 perfect types (58.1%), 10 imperfect types (32.3%), 1 compound perfect type (3.2%) and 2 compound imperfect types (6.4%). The repeat unit of the microsatellite core sequence is different in each probe. The highest repeat unit for TC and TG probes is 28 and 15, respectively, and the lowest repeat unit for TC and TG probes is 7 and 11, respectively. The primer specificity test on 31 primer pairs showed that products can be amplified from all seven bumblebee species with 26 primer pairs, and the other 5 primer pairs were found to be specific for some of the seven species, of which one primer (BPM5) was found to be specific for B. pyrosoma. These novel microsatellite markers will be useful not only for future studies on the genetic structure, molecular evolution and resource conservation of this endemic species, but also for population genetic studies of other Melanobombus species.

Many insects possess sensitive taste perception systems which play crucial roles in the processes of food selection, mating, and oviposition. The mechanism of taste perception is less studied compared to that of olfaction perception in insects. Most of the traditional taste studies are about the morphology and electrophysiology of gustatory sensilla, and behaviour. With the development of techniques on insect molecular genetics, bioinformatics and neurobiology in current years, taste perception mechanisms in insects have been better understood mainly in the following two aspects: (1) Insect gustatory receptor proteins (Grs): putative Grs of many insect species have been identified by bioinformatics, and the number and the protein sequences of Grs are extraordinarily divergent among different species of insects. In general, the Grs can be classified into phagostimulatory receptors and deterrent receptors based on the corresponding ligands. (2) Projections of gustatory sensory neurons on the central nervous system and neural coding mechanisms:  projection of gustatory sensory neurons to different regions of the suboesophageal ganglion and the tritocerebrum of brain in insects has been investigated. This article reviews the research advances concerning basic characteristics of gustatory sensilla and gustatory sensory neurons, evolution, expression and function of Grs, projections of gustatory sensory neurons and plasticity of taste in insects.

 The pea aphid, Acyrthosiphon pisum, is an important piercingsucking pest. The secreted saliva plays roles in feeding host plants and virus transmission. In order to explore the function of saliva proteins, we cloned an unknown protein family that is highly expressed in salivary glands of the pea aphid. The family consists of 13 genes, which encode 14 proteins, and four of them are highly expressed in salivary glands. The family is unique to aphids and enriched in cysteine. Fourteen cysteines are conserved, 6 of which form three CXXC domains. Genes of this family have no introns and are distributed in 9 scaffolds of the aphid genome. Semi-quantitative reverse transcription PCR showed that there was no stage-specific expression for this family. We speculate that the expression of this family may be tissue-specific and this protein family probably has the functions of oxidoreductases or DNA methyltransferases.

Vacuolar-type H⁺-ATPase (V₁V₀-ATPase, V-ATPase), a type of proton pump, functions in almost every eukaryotic cell. In this study, a V-ATPase G subunit gene was cloned from Bactrocera dorsalis and named as BdorATPG. The open reading frame of BdorATPG is 354 bp in length, encoding 117 amino acid residues. Homology analysis showed that BdorATPG has high similarity with corresponding regions of V-ATPase G subunits from other dipteran insects, and shares 88.9% amino acid identity with the V-ATPase G subunit from Drosophila pseudoobscura. Three-dimensional structure modeling results showed that the N terminal (1-59 amino acids) sequence of BdorATPG is α-helix structure, and the hydrophilic and hydrophobic residues are almost symmetrically distributed on both sides of the helix. Real-time PCR analysis revealed that BdorATPG mRNA was expressed in all tissues, while the highest expression level was detected in the antenna. The BdorATPG mRNA level in male genital segments was about 6.04-fold as high as that in female genital segments, suggesting that V-ATPase plays an especially important role in male reproductive physiological processes.