To verify whether the signal peptide sequence of fibroin H chain (fib-H) functionally possesses the activity in the middle silk gland, based on the characteristics of the strong promoter of the silk protein gene and the high level secretion of silk protein of the silkworm, Bombyx mori, we constructed the promoter ser-HS of sericin-1 gene (ser-1) with the signal peptide sequence of fib-H. Then, we constructed the transitorily secretory expression vector pSK-serHS-DsRed-polyA via driving the DsRed gene with the promoter ser-HS. We transfected pSK-serHS-DsRed-polyA into BmN cells by liposome. From the cells transfected with the vector, the red fluorescence could be detected, which verified that the expression vector could express DsRed in BmN cells transiently. Furthermore, when silkworm had been injected with the expression vector pSK-serHSDsRed-polyA, red fluorescence could be observed in the lumen of the middle silk gland of silkworm. The results indicated that DsRed was expressed transiently and was secreted into the lumen of the middle silk gland. We concluded that the cloned signal peptide sequence of fib-H possesses the biological functions of the signal peptide in the middle silk gland.

We had found that the parasitization by Cotesia vestalis and Diadegma semiclausum inhibited their host larval spermatogenesis seriously. This study intends to compare the testicular growth and the formation of sperm bundles in Plutella xylostella parasitized by the above two endoparasitoids, so as to make clear of the regulation capabilities of parasite factors on host reproductive system. By using the methods of superparasitism and pseudoparastism, the changes in testicular volume and morphology of spermatogenic cells and sperm bundles during the host larval spermatogenesis and spermiogenesis parasitized separately by the two endoparasitoids were compared. The results showed that parasitization by the two endoparasitoids both resulted in a reduction in the number of sperm bundles, and the spermatogenesis and spermiogenesis were retarded too. The abnormal testis structure or deformed sperm bundles were observed in P. xylostella parasitized by the two wasps. The degree of testis degeneration was more severe in P. xylostella parasitized by C. vestalis than that by D. semiclausum. Superparasitization induced more pronounced parasitic castration when compared with a single parasitism. After superparasitization separately by C. vestalis and D. semiclausum, the host testicular volume was 0.005 mm³ and 0.008 mm³, only 33.1% and 33.6% of their singly parasitized host testicular volume, respectively. Pseudoparasitization also resulted in testis degeneration, and the degree of degeneration was almost as severe as in the naturally parasitized hosts, suggesting that polydnavirus and venom are involved heavily in host castration. It is so inferred that the mechanisms adopted by the bracovirus and ichnovirus in host castration may be different.

In order to screen the infochemicals and their combinations, which effectively attract the important natural enemies Apanteles sp. parasitizing the larvae of tea geometrids Ectropis obliqu Prout, 27 representative volatile compounds from the intact tea shoots and tea shoots damaged by tea geometrids, tea green leafhoppers Empoasca vitis Gothe and tea aphids Toxoptera aurantii Boyer were chosen and prepared into liquid paraffin solution at the dosage of 10 ^-2 g/mL, respectively. The equivalent E-2-hexenal, Z-3-hexen-1-ol and linalool paraffin solution were prepared into blend 1, and the equivalent E-2-hexenal, Z-3-hexen-1-ol, 2-penten-1-ol, E-2-pentenal, Z-3-hexenyl acetate, n-pentanol, n-hexanol and 1-penten-3-ol paraffin solution into blend 2. The female parasitic wasps of 1-2 d old were used as the test insects. The results of electroantennogram (EAG) responses showed that the difference among EAG values from these odor resources reached the significant level of P<0.05. The fatty acid derivatives elicited the strongest antennal-electrophysiological responses, the next were aromatics and isothiocyanate, and the third sesquiterpenes and monoterpenes. The single component eliciting stronger responses were Z-3-hexenyl acetate, E-2-hexenal, methyl salicylate, E-2-pentenal, acetophenone, phenethyl alcohol, benzyl alcohol, benzaldehyde and methyl jasmonate; the single components eliciting weaker responses were 1-penten-3-ol, 2-penten-1-ol, Z-3-hexen-1-ol, geraniol, ocimene, α-terpinen, (+)-cedrol, (+)-3-caren, α-humulen, and β-ionone; the single component eliciting the least responses was Z-jasmone. The blend 1 elicited the highest EAG value, while the blend 2 elicited the low EAG value. Eight odor resources eliciting higher EAG values, including methyl salicylate, E-2-hexenal and blend 1, were selected and used in behaviour assay by Y-shaped olfactometer. The results accorded with those of EAG responses on the whole. So methyl salicylate and E-2-hexenal were again selected, and methyl salicylate solution at the dosage of 10^-3, 10^-2 and 10^-1 g / mL, as well as the blend of methyl salicylate plus E-2-hexenal at the dosage of 10^-2 g / mL were prepared with hexane as solvent. These solutions were loaded onto the lures, which exhibited the intense attraction to Apanteles sp. and other braconids with the dosage gradient effect in the tested tea gardens in Zhejiang, Yunnan, Fujian and Guangdong Province. It is so concluded that the synomones from the tea shoots induced by pests damaging can elicit the strong EAG responses and taxis of Apanteles sp., and the appropriate combinations of synomone plus synomone or common plant volatiles can effectively attract the wasps.

Pheromone binding proteins (PBPs) play an important role in communication between male and female insects. The open reading frame and 3′ end full-length cDNA of a novel pheromone binding protein 2 gene was cloned from Helicoverpa assulta (Guenée) by using RT-PCR and RACE methods, which was named HassPBP2 (GenBank accession no. EU316186). The cloning and sequencing results showed that the full-length of open reading frame in HassPBP2 was 450 bp, encoding 149 amino acid residues with the predicted molecular weight and isoelectric point of 16.9 kD and 5.56, respectively. Gene structure analysis revealed that HassPBP2 consists of 3 exons and 2 introns with length of 90 and 261 bp, respectively. Amino acid sequence analysis showed that the deduced amino acid sequence of HassPBP2 had the characteristics of odorant binding proteins. HassPBP2 had 34%-91% identity with PBPs of other Lepidoptera moths, and shared 91% identity with the PBP2 sequences from H. armigera and Heliothis virescens. Temporal expression revealed that HassPBP2 transcript was observed clearly from mid-stage pupa to mid-stage adult, but not in the egg, larva and early-stage pupa. The tissue analysis further indicated that HassPBP2 was only expressed in the antennae of both male and female adults.

Protein expression in different larval instars of the diamondback moth (DBM), Plutella xylostella, was characterized by two dimensional gel electrophoresis (2-DE). Twenty-four differentially expressed protein spots were discriminated. The spot 1111 was selected for peptide mass fingerprinting (PMF) and peptide sequence using matrix-assisted laser desorption ionization of time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS). The PMF was used to search for the matched protein based on NCBInr Metazoa database with MASCOT and ProFound softwares, but the match was unsatisfied. The PMF+MS/MS spectrum was further used to search for the matched protein, and the protein was identified as GA18218-PA of Drosophila pseudoobscura based on the NCBInr Metazoa database while it was identified as the subunit d of H⁺ transporting ATP synthase of Bombyx mori based on the EST database of DBM population. To validate the result of matching, the spot was used for chemical N-terminal derivatization of the tryptic peptides with 4-sulfophenyl isothiocyanate (SPITC) prior to MALDI-TOF/TOF MS, and the protein was identified as a subunit of ATP synthase again. Finally, potential application of MS analysis and bioinformatics as tools to select the optimal method in proteomic research on non-model insects was discussed in some detail.

【Objective】 This study focused on the effects of fenoxycarb, a juvenile hormone analog (JHA), on the ladybird Harmonia axyridis and discussed its mechanisms of action, so as to evaluate the risks of fenoxycarb application and provide theoretical basis for rational use of the JHA. 【Methods】 Toxicity of fenoxycarb to egg, 2nd instar larva, pupa and adult of H. axyridis was determined in the laboratory by using the methods of dipping, topical contact and residual film, respectively. 【Results】 Fenoxycarb significantly disrupted embryonic development of newly-laid eggs at the minimum concentration of 0.0001 μg/mL, but when the 2 d-old eggs were treated, the larvae could hatch even at the highest concentration of 20 000 μg/mL. The mortality of 2nd instar larvae was very low even at the highest concentration of 4 000 μg/mL. When pupae were treated, fenoxycarb had significant effects on pupal development with adult eclosion blocked, and pupa-adult intermediate and abnormalities of adults emerged at the minimum concentration of 0.0001 μg (a.i.)/larva. The adult vitality was affected significantly at 24 h after contact with fenoxycarb at the concentration of 0.0125 μg/mL. 【Conclusions】 Fenoxycarb had an obvious ovicidal action on newly-laid eggs of H. axyridis, seriously blocked the larval-pupal metamorphosis and affected the survival of the adults. When fenoxycarb is used in fields, the susceptible developmental stages of the ladybird should be avoided.

To increase the reproduction rate of Spathius agrili Yang (Hymenoptera: Braconidae), an effective larval parasitoid of emerald ash borer, Agrilus planipennis, in China, the effects of different temperatures (22, 24, 26, 28, 30 and 32℃) on the development and reproduction of this wasp were investigated in the laboratory. The results showed that the developmental rate of egg, pupa and the whole generation of S. agrili increased with the increase of temperature from 22℃ to 32℃, but the highest developmental rate of larva was at 26℃. The developmental threshold temperatures required by egg, larva, pupa and whole generation were 14.34, 16.89, 14.16 and 13.84℃, respectively, while the effective accumulated temperatures were 24.59, 61.16, 166.27 and 276.80 degree-days, respectively. Temperature had effects on the parasitism rate, the rate of successful parasitism, number of eggs laid, the number of wasps and the sex ratio of the offspring with different degrees. It is so proposed that the suitable temperature for artificial rearing of S. agrili ranges from 26℃ to 28℃.

To explore the adult oviposition and larval feeding preferences of Spodoptera exigua (Hübner) to different host plants and their relationship, adult oviposition and larval feeding preferences of the moth on seven host plants, i.e., maize Zea mays L., cowpea Vigna unguiculata (L.) Walp., cabbage Brassica oleracea L. var. capitata L., cucumber Cucumis sativus L., cotton Gossypium hirsutum L., pepper Capsicum frutescens L. and tomato Lycopersicon esculentum Miller, were assessed by selection and non-selection tests. Behavior response of S. exigua females to three plants (maize, cabbage and cucumber) and their volatile extracts were also tested by Y-type olfactometer. The results of the field non-selection oviposition preference test indicated that the amount of S. exigua eggs on different plants ranked as maize > pepper > cotton > cucumber, cowpea, and tomato > cabbage. In the Y-type olfactometer tests, females showed the strongest behavioural response to maize and its volatile extract, less response to cucumber, and the weakest response to cabbage. The results of behavioural response tests were in accordance with the results of the oviposition preference tests. Host plant feeding preference of S. exigua larvae at different instars differed to some extent with the prolonged observation period. Young larvae of the 1st and 2nd instars preferred to feed on cowpea, maize and cucumber, but not on cabbage, tomato, pepper and cotton. Larvae of the 4th and 5th instars also showed feeding preference to pepper. Feeding preference of the 5th instar larvae was not as obvious as the earlier larvae. These results suggest that the oviposition preference of S. exigua to different host plants differs significantly, the plant volatiles play important roles in its oviposition host selection, and adult oviposition and larval feeding preferences of S. exigua are not consistent.

It has been noted that insect community is a powerful indicator of forest discover and succession. We examined the changes in species diversity and faunal composition of insect along a successional gradient of conifer and broad-leaved mixed forests in Changbai Mountain in this study. Insect community of three habitats, viz. secondary birch forest （SBF）, secondary conifer and broad-leaved mixed forest (SCBF), and original broad-leaved Korean pine forest (OBPF), from the early successional stage to mature forest understory were investigated by using sweeping nets, light traps and pitfall traps. The results showed that a total of 8 183 individuals representing 699 species in 362 orders were recorded. The dominant species were of Lepidoptera and Coleoptera. SCBF had the highest number of individuals and OBPF had the highest number of species, but the number of species and individuals between the successional habitats did not differ significantly. The Fisher’s α index values of SCBF and OBPF were significantly greater than that of SBF, and the diversity at the family level was not significantly different between the three habitats. Insect diversity increased following the herb diversity along the successional habitats. Because of different feeding habits and habitat preference, the diversity of Lepidoptera increased along the successional habitats, while that of Coleoptera decreased, which was similar to that found in previously reported studies.

This paper deals with a taxonomic study of Tagasta Bolivar, 1905 from China, with a description of a new species Tagasta gui sp. nov. The new species is similar to T. marginella (Thunberg, 1815), but the tegmina short, only reaching the base of epiproct in male; lateral lobe of pronotum without white lower margin and hind tarsi baby pink. A key to known species of the genus Tagasta from China is given. The type specimens are deposited in the Museum of Hebei University (MHU), China.

In order to understand the interactive mechanisms of Aphis gossypii Glover and its host plants, the changes in major body constituents, viz. crude protein, fat, sugar, amino acid and fatty acid, of A. gossypii on five host plants, viz. Cucumis sativus, Cucurbita moschata var. melonaeformis, Cucurbita pepo var. medullosa, Lagenaria siceraria var. turbinata and Cucumis melo var. saccharinus, were investigated by micro-Kjeldahl method, Soxhlet extraction, anthrone colorimetry, hydrochloric acid hydrolysis method and gas chromatography, respectively. The results showed that the contents of the above constituents were significantly different among the aphids reared on different host plants. The dried aphids contained 35.40%-45.25% crude protein, 24.01%-30.33% fat and 4.09%-7.91% sugar depending on the host plants. Eighteen amino acids existed in the body of the aphid, mainly glutamate (5.15-6.97 mg/100 mg, dry weight), aspartic acid (3.75-5.33 mg/100 mg) and leucine (2.59-3.60 mg/100 mg), and the least was cystine (0.44-0.49 mg/100 mg). There were 8 kinds of fatty acids in the aphids. The highest content was palmitic acid (10.53%-15.55%), then myristic acid (3.32%-9.93%), and the least was linolenic acid (0.04%-0.17%) in the aphids fed on the other four host plants except for L. siceraria var. turbinata, on which the most abundant was myristic acid (16.20%) and the second abundant palmitic acid (7.15%). The dried aphids contained 20.08%-27.72% saturated fatty acids and 2.58%-3.84% unsaturated fatty acids. The results suggest that the host plants affect significantly the major body constituents of A. gossypii.

In order to identify organs and behavior closely related to reproduction, observations on reproductive system and reproductive biology of the alligatorweed flea beetle, Agasicles hygrophila were conducted in the laboratory. The results showed that the female adult have 2 ovaries, each of which contains 12-16 telotrophic ovarioles, spermatheca is in the shape of bean sprout, and the aedeagus is fork-type. Ovarian development can be divided into 5 grades based on the morphological characteristics of ovaries: stage Ⅰ (No oocyte stage), stage Ⅱ (Previtellogenic stage), stage Ⅲ (Egg maturation stage), stage Ⅳ (Ovipositing stage), and stage Ⅴ (Post-oviposition stage). Each stage shows significant differences in the length of ovarian zones and egg-carrying number. In addition, the beetles could mate around 2 d after emergence, a copulation peak appears on 16：00-18：00, the oviposition peak occurrs on 12：00-16：00, and the beetles prefer to the blade back of leaf in the middle stratum of host. Temperature had a significant effect on longevity and fecundity. Female longevity and fecundity decreased with increasing of the temperature within 22-32℃, and temperatures below 22℃ or above 32℃ were unfavorable for ovarian development. At 32℃, the pre-oviposition period extended to 7.2 d, while the longevity and fecundity decreased significantly. Therefore, it is inferred that high and constant temperature above 32℃ is a possible cause for the population decay of the alligatorweed flea beetle in summer.

        The mealybug species, Phenacoccus solenopsis Tinsley has caused severe economic losses during the last two decades in many countries. Recently this alien invasive species has been introduced in China and threatened the agricultural production. The rapid and accurate identification of the species has been the basis of the scientific research and management of the alien invasive species (IAS). In this study, the mitochondrial cytochrome oxidase subunit I (mt COⅠ) of the P. solenopsis materials collected from Sanya City and Lingshui County, Hainan Province were sequenced and compared with the known sequences of the species from Florida of the USA. We unexpectedly found that there were two divergent clades in the mealybug species, P. solenopsis, based on the phylogenetic tree. The genetic distance between the collections from China and those from the USA was approximately 3%. This was the first report on the molecular identification of P. solenopsis in China based on the mt COⅠ marker. These data suggest that P. solenopsis might be a species complex which includes at least two cryptic lineages or sibling species. The newly collected P. solenopsis materials from Sanya and Lingshui are of a cryptic lineage or species in the complex. The data also suggest the source of Sanya and Lingshui populations of P. solenopsis in the present study might not come from Florida of the USA. The discovery of the cryptic lineages in P. solenopsis complex is helpful for its accurate identification and the future research in its invasion ecology.

The complete sequences of rDNA ITS1 and ITS2 were determined for the brown planthopper Nilaparvata lugens, the white-backed planthopper Sogatella furcifera and the small brown planthopper Laodelphax striatellus in order to explore the molecular identification method for them. The flanking regions of rDNA-ITS1 and ITS2 of the three planthoppers showed only limited variation, but the sequences of rDNA-ITS1 and ITS2 differed significantly. There are 294 variable sites in the 438 analyzed sites for the ITS1 region, and 177 variable sites in the 403 analyzed sites for the ITS2 region. Species-specific primers of N. lugens, S. furcifera, and L. striatellus were designed based on their rDNA-ITS1 and ITS2 sequences. The results of PCR amplification of rDNA-ITS1 in the three species indicated that the species-specific primers were not applicable. However, the species-specific primers based on the rDNA-ITS2 sequences proved to be useful diagnostic primers for the three planthoppers. It is so concluded that molecular identification of N. lugens, S. furcifera and L. striatellus using the species-specific primers from the rDNA-ITS2 region is feasible.

【Objective】Analysis of genomic DNA polymorphism and the related sequence of Demodex folliculorum and D. brevis. 【Methods】 The genomic DNA of the human Demodex was extracted by using improved DNA extraction method of mini-insects. Random amplified polymorphic DNA (RAPD) was applied to analyze the polymorphism. The related bands were connected with pMD18-T vector, and cloned, sequenced, and identified and analyzed after enzyme digestion. 【Results】 There were 15 bands obtained in D. folliculorum and 12 in D. brevis. Some bands were shared by the two mites while others were species-specific. The genetic distance between the two Demodex species was 0.5556. After recombination, the sequence of the specific band (about 800 bp) of D. folliculorum was found to be 855 bp (GenBank accession no. FI277970) in size. The 855 bp fragment was confirmed to be characteristic for D. folliculorum according to the PCR result with a specific primer and the result of enzyme digestion analysis. This sequence had 46% similarity to AraC-type DNAbinding domain-containing protein. The shared fragments (about 300 bp) by the two mites were both 341 bp in length (GenBank accession no. FI520176 and FI520175, respectively), and with two different bases at the 84th and 165th sites, which were A/G and C/T permutation, respectively. Their homology was 99.4%, but there was no ORF and high similar sequence. 【Conclusions】 The 855 bp fragment is specific to D. folliculorum. The 341 bp fragment is shared by D. folliculorum and D. brevis with 99.4% homology. RAPD can be used in genomic DNA polymorphism analysis and species identitfication of D. folliculorum and D. brevis.

In many areas in China, Chrysomya megacephala F. has gradually invaded the ecological niches occupied by Musca domestica L. and become the dominant species at garbage sites in the urban areas. To explore the influence of foods on the development of M. domestica and C. megacephala larvae when they were reared solely or jointly, the oviposition preference and life history of the F1 generation of wild blowfly C. megacephala and housefly M. domestica on wet wheat bran, pork muscle and their mixture were observed in the laboratory. The results showed that: (1) Blowflies preferred to lay their eggs on substrates containing pork muscle while houseflies preferred to lay their eggs on substrates containing wheat bran. (2) Newly-hatched housefly and blowfly larvae could reach adulthood on diets containing pork muscle. When raised on wheat bran, newly-hatched housefly larvae could reach adulthood while newly-hatched and 2nd instar blowfly larvae all died before entering into the next instar, but some 3rd instar blowfly larvae could reach adulthood. (3) When the same number of newly-hatched housefly and blowfly larvae grew mixedly on diets containing pork muscle, blowflies exhibited shorter developmental duration and higher survival rate than houseflies. When reared mixedly with houseflies on wheat bran, blowflies showed shorter developmental duration and higher survival rate than the same instar blowflies that grew solely on wheat bran. These results suggest that in coexistence the housefly can promote the utilization of the vegetable resource by the blowfly. This might be one of important reasons why the blowfly can invade successfully the ecological niches occupied dominantly by the housefly.