An embryo cell line of Bombyx mori, named BmE-SWU2, was established after one year primary culture. The cells are relatively single, short shuttle-like or round, and very small in shape. The cell line belongs to adhesive-type epithelium. The cell doubling time was 51.8 h. The ratio of duple cells was 89.76％. Thus, the cell line belongs to duple cell line. The chromosomes of BmE-SWU2 was typical of Lepidoptera, namely the chromosomes in metaphase were short pole-like or granule-like and the centromeres dispersed-type. BmE-SWU2 was more sensitive to BmNPV. The 50% tissue culture infection dose （TCID₅₀） was 1.581×10^-7.

The zinc ribbons are one group of diverse zinc finger proteins. Most zinc-ribbon domain is actually folded as three-stranded antiparallel β-sheets in their structure instead of finger-like helices. The zinc ribbon is a domain that functions as interaction modules binding to nucleic acids. The zinc ribbon proteins perform a broad range of functions such as replication and repair, transcription and translation as a transcriptional repressor.Through searching cDNA bank of silkworm pupae, a unique EST (GenBank accession no. DY230964) encoding the zinc ribbon protein was identified. In order to obtain full-length cDNA in Bombyx mori, we used this sequence as a probe and performed in silico cloning based on the B. mori EST database. A contig was thus assembled on the basis of several ESTs. It was also verified by RT-PCR. PCR product was purified and ligated intopGEM-T-easy vector. The recombinant clones were sequenced, which had the same sequence as the contig. We nominated this novel gene encoding zinc ribbon domain containing protein as BmZNRD1 (GenBank accession no. DQ432055). The full-length of the gene is 675 bp. It contains an ORF of 363 bp, 10 bp nucleotide sequence in 5′ UTR (untranslated region) and 302 bp nucleotide sequence in 3′ UTR (untranslated region). It encodes 120 amino acids and is highly homologous to those of eukaryotic organisms previously reported (about 60%), with their predicted mass 13.54 kD and isoelectric point 6.8. The deduced amino acid sequence is one of zinc ribbon proteins with two putative functional domains, the N-terminal domain C_x2C_x14C_x2C and the C-terminal domain C_x2Cx₂₄C_x2C. The highly conserved amino acid sequence within the C-terminal domain is C_x2C_x6Y_x3QxRSADE_x2TxF_x2C_x2C, which is well conserved through evolution,in organisms such as yeasts, Drosophila, nematodes, amphibians and mammals, and highly homologous to the yeast RNA polymerase A subunit 9 and transcription-associated proteins. An alignment of the cDNA sequence with the silkworm genome sequences revealed that there were 3 exons and 2 introns in the gene of  BmZNRD1, and all of them conformed the canonical GT-AG rules.

A cDNA clone encoding a pheromone binding protein 3 from antenna of Helicoverpa assulta (named HassPBP3) was isolated by reverse transcription polymerase chain reaction (RT-PCR). The cloning and sequencing results showed that the full length of HassPBP3 open reading frame (ORF) was 495 bp, encoding 164 amino acid residues, and the predicted molecular weight (MW) was 18.5 kD. The N-terminus hydrophobic region predicted containing of 22 amino acid residues within the HassPBP3 displayed the characteristic features of a signal peptide. Thus, the mature protein should consist of 142 amino acids with a calculated molecular weight (MW) of 16.1 kD and isoelectric point (IP) of 5.44. The gene was then constructed into expression vector pGEX-4T-2 for over expression in prokaryotic cells. The SDS-PAGE and Western blot analysis showed that induced by IPTG, the PBP3 proteins in H. assultawas expressed in Escherichia coli BL21, and its MW was found to be about 42 kD by checking with SDS-PAGE, nearly equal to the predicted.

Parafilm method was adopted for feeding the third instar nymphs of Macrosiphum avenae on two liquid diets (20% sucrose and redistilled water). Their saliva after feeding for 24 h was collected and assayed identifying salivary enzymes and determining their activities. The results showed that pectinase, polyphenol oxidase and cellulase were identified in 20% sucrose diet; cellulase was identified in redistilled water diet; peroxidase was not identified in both diets. The activities of pectinase, polyphenol oxidase and cellulase secreted into 20% sucrose diet by 30 aphids were 2.59×10^-3 U/g, 7×10^-3 U/g and 7.89×10^-3 U/g, respectively; and cellulase activity secreted into redistilled water diet by 30 aphids was 3.68×10^-3 U/g. In the behavioral response test, the predator Coccinella septempunctata and parasitoid Aphidius avenae of M. avenae showed much preference for the volatiles in wheat seedlings treated by pectinase. It was so concluded that pectinase secreted by M. avenae play an important role in wheat plant indirect defense induced by aphid feeding.

 

The sublethal effect of insecticides and SlNPV on the activities of superoxide (SOD),catalase (CAT) and peroxidase (POD) in Spodoptera litura was investigated under 28℃. The results showed that the SOD activity in the treatment of chlorpyrifos and SlNPV mixture was significantly higher than those in the treatments of chlorpyrifos, SlNPV and the water control. It was 1.18, 1.35 and 1.25 times that of the water control at 12, 24 and 36 h, respectively. The SOD activity in the treatment of chlorfenapyr and SlNPV mixture was lower than those in the treatments of chlorfenapyr, SlNPV and the water control after 12 h. The CAT activity in the treatment of chlorpyrifos and SlNPV mixture was significantly higher than those in the treatments of  chlorpyrifos, SlNPV and the water control. It was 2.79, 1.09 and 1.53 times that of the water control at 12, 24 and 36 h, respectively. The CAT activity in the treatment of chlorfenapyr and SlNPV mixture was lower than those of the water control except at 12 h. POD activity could not be investigated in S. litura. It was obvious that there was a great difference in the activity of CAT mostly after treatment of the mixture of insecticides and SlNPV.

 

 

 

For assessing impacts of Bt rice on the non-target insects, the population parameters of the white-backed planthopper, Sogatella furcifera (Horvath) fed on transgenic cry1Ab rice varieties KMD1 and KMD2 and their parent rice variety XS11 were assayed in the laboratory. The results showed that the innate capacity for increase of S. furcifera on KMD2 was lower than that on XS11 due to the significant reduction of oviposition duration (7.6 d on KMD2 and 12.7 d on XS11, respectively) and the number of eggs laid per female (95.0 on KMD2 and 167.5 on XS11, respectively). The chemical analysis indicated that this might be resulted from the significant difference of contents of total free amino acids, particularly two free amino acids (Ala and Glu) between KMD2 and XS11. But the effect of KMD1 was not the same as that of KMD2 except that there was also a significant reduction of oviposition duration (8.6 d on KMD1). The results suggested that feeding on different rice varieties might have different effects on population development of S. furcifera.

Based on the sex determination of Hymenoptera parasitic wasps that unfertilized egg develops into a male while fertilized egg develops into a female, the insemination potential of male Trichogramma ostriniae and its relationship with body size, age and the number of copulations were studied. The results showed that spermary of T. ostriniae had been set before the eclosion and no sperm was produced in the adult stage. A male adult could inseminate 8-23 females during its lifetime, and approximately breed 346.15 female progenies. Males exhausted their sperms or seminal fluid in 24 hours after emergence when provided with unlimited virgin females. Though male adults would continue to copulate with females afterwards, no female offspring had been observed. The insemination potential of a male T. ostriniae was closely linked with the number of copulations, and sperm quantity gradually decreased as more copulations performed. The male adult could provide more sperms to females in its initial copulation, and approximately fathered 58.85 female progenies. However, with the increase of the number of copulations and consumption of sperms, fewer and fewer sperms could be transmitted to females. A male could father no more than 10 female progenies after 10 copulations. The insemination potential also showed that it was positively related to body size. Bigger males could copulate more and breed more female progenies.

In order to examine the interaction between pest population and environment as well as biology and ecology of the citrus flat-headed borer, Agrilus auriventris Saunders, spatial distribution pattern of the borer was studied by investigating the distribution of adult emergence holes in citrus plants. The results showed that the emergence holes of the borer were distributed in crowds both in trees and in orchards. The fitting tests for spatial distribution pattern, analysis of the aggregative indexes and the Taylar's law showed that the emergence holes revealed an aggregative negative-binomial distribution pattern in died trees, negative-binomial distribution or Neyman type A distribution in half died trees, and negative-binomial distribution in orchards. Based on Iwao regression, the basic element for the distribution was clusters of individuals both within trees and within orchards, and the individuals attracted each other. Trees with low growth vigor were vulnerable to the pest, while healthy trees could kill the larvae by gummosis. Therefore, aggregative multi-attacking strategy was used by the pest to conquer the host plants. In general, the beetle attacked in crowds a part of the trees in the orchards and the middle or basal part of the trunks in trees, and then next generations attacked the wounded trees again and again as the growth vigor of citrus trees descended, where larvae could succeed in completing development, and finally conquered the host plants.

The effect of constant temperature and relative humidity on the development and reproduction of the tomato russet mite (TRM), Aculops lycopersici (Massee) was investigated. The results showed that the survival rate of TRM were highly effected by rearing temperature and relative humidity, the highest was 89.9% at 23℃ (53%RH) and 87.1% at 75.5%RH (26℃). The developmental duration of TRM decreased as rearing temperature increased from 14℃ to 35℃, and increased as relative humidity increased from 30% to 100%. The developmental zero of egg nymph and from egg to adult of TRM were 10.51℃， 9.02℃， and 9.15℃, respectively. A total of 105.56 degree-days above a developmental zero of 9.15℃ were required to complete development from egg to adult emergence. The obvious effect of temperature and humidity on the reproductive rate of TRM was observed. It was found that the duration of oviposition decreased with increasing temperature and increased with increasing humidity. Fecundity was highest at 26℃ (53%RH) and 53%RH (26℃) with 44.3 eggs and 42.2 eggs laid per female, respectively. The highest intrinsic rate of natural increase was observed at 26℃ (53%RH) and 53%RH (26℃) as 0.2645 and 0.2669, respectively. The results showed that the optimal temperature interval for its development should be within 26-29℃ and the optimal humidity interval be within 53%-75%RH.

Researches on herbivory insect saliva in recent years have revealed that insect salivary components play important roles in relationships and coevolution between insects and plants. A variety of enzymes and organic components in saliva of herbivory insects can induce series of biochemical responses in damaged plants which could be very specific to species or even to larval instars of the feeding insects. It has been demonstrated that enzymes, such as  β-glucosidase, glucose oxidase, etc., and organic chemicals, such as volicitin, can trigger induced defense responses in plants. However, there have been no direct evidences that salivary components of piercing_sucking insects play roles in induced plant chemical defenses even though plants also responded to feeding by these insects. Salivary components of herbivory insects are variable with host plant species most likely due to biochemical or physiological adaptation of insects to nutrients and toxins in different plants. Insect protein analyses indicated that similar salivary components were found in insects with the same types of mouth parts and similar food resources. Researches in salivary components of herbivory insects may elucidate mechanisms in insect-plant coevolution, formation of insect biotypes, outbreaks and damage of insect pests， and may also have significance in guiding insect pest management.

Among many kinds of insect semiochemicals, lepidopterous sex pheromones have been studied at the most depth and identified from females of more than 565 species in the world. However, scientists continue to be surprised at the diversity of the chemical structures of the pheromone components and their elaborate blending to produce species-specific communication systems, which play an important role in the reproductive isolation of sympatric insects. The studies of lepidopterous sex pheromones are related with ecology, biochemistry and genetics. In this paper we briefly reviewed and discussed the advances in moths' sex pheromone diversity, sex pheromone molecule structure identification, microcomponent function, application of synthetical sex pheromones, sex pheromone product enzymes, sex pheromone product regulative mechanism and sex pheromone receipt mechanism.

Phenotypic plasticity is the ability of an organism to express different phenotypes based on genetic basis under different biotic or abiotic environment. Aphids are small herbivorous insects, renowned as pests of economic significance in agriculture, horticulture and forestry. Aphids often exhibit diverse phenotypes, corresponding to the change of environmental factors, such as host plants, temperature, light and natural enemies. For example, phenotypic plasticity of aphids can be influenced by such factors of host plants as species and varieties, growth stages, and even amino acids composting of the host plants. High or low temperature can influence survival, fecundity and longevity, and determine the form of winged or wingless morphs of aphids. It had been proved by RAPD-PCR, SSR or other molecular markers that those phenomena were the integrated results of the host plants, temperature, species and clones of aphids. There were biological, ecological and genetic differences among the clones of different colours and among seasonal populations of aphids. It is helpful to analyze impacts of the above-mentioned factors either in research on the evolution or the control of aphids. In addition, issues that may be needed to study in the future are discussed at the last paragraph, including epigenetic regulation (DNA methylation, histone code, X-inactivation, genomic imprinting), the importance to study the winged aphids, and effects of global climate change on the evolution of aphids.

The beet armyworm Spodoptera exigua(Hübner) is a serious insect pest and has caused serious economic losses in China in last decade. For further understanding the population dynamics and improving the forecast and control of this species, the DNA polymorphism of 7 geographic populations from various locations of mainland China was analyzed by using amplified fragment length polymorphism (AFLP) technique. The results showed that the maximum genetic similarity of S. exigua individuals between geographic populations was 0.824, and the minimum was 0.143;  the maximum genetic similarity of S. exigua individuals within geographic populations was 0.786 and the minimum was 0.250. The genetic similarity of some samples within geographic populations was lower than that of some samples between geographic populations. The genetic diversity of Jiangxi population was the lowest (the proportion of polymorphic bands was 80.7%) and that of Shandong population was the highest (the proportion of polymorphic bands was 88.6%). The genetic diversity of S. exigua from northern areas was higher than that from southern areas on the whole. The results of cluster analysis showed that 42 individuals of 7 populations did not relate to the geographic locations where they were collected, suggesting that the genetic differentiation is not obvious in all the populations studied. The northward and southward migration by the adult beet armyworm is the most possible explanation for these results, since other direct or indirect evidences has shown that it is a true migrant species in the country.

 

Double standard deviation analysis with 11 math-morphological features (MMFs) ( such as area, perimeter, etc. ) from the images of 23 species of insects of the Pentatomidae, Coreidae, Noctuoidea, Saturnijdae, Pieridae, Melolonthidae, Rulelidae and Cerarnbycidae families was made to assess its use in insect taxonomy at family level. The results indicate that the ranked reliability of MMF in the identification of insect families is, from high to low:  roundness likelihood, eccentricity, circularity＞X-length, form parameter, lobation＞area, perimeter, sphericity＞Y-length, hole number. From the perspective of mathematical morphology, the kinship can be ranked as follows: Pentatomidae and Coreidae＞Rulelidae, Cerarnbycidae and Melolonthidae＞Noctuoidea, Saturnijdae and Pieridae. The results are similar to those of statistical hypothesis testing analysis.