Acta Entomologica Sinica

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Molecular mechanisms of juvenile hormone action

LIU Ying

2008, 51 (9): 974-978.

Abstract （10223）

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Ecdysteroids (Ecd) and juvenile hormones (JH) play critical roles in regulating insect development and (metamorphosis. Though the molecular mechanisms of Ecd action are well understood now, those of JH action, in contrast, are still poorly known mostly because the JH receptor has not been successfully identified yet. In this review, we described three aspects of recent progresses in molecular mechanisms of JH action. 1 . JH and Ecd cross-talk with each other at the molecular level. JH modulates or suppresses Ecd signal to regulate insect development and metamorphosis. 2. Met and USP are two potential JH nuclear receptors. 3. JH also transduces signal via membrane receptor and protein kinase C.

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INTERACTION BETWEEN THE APHID-SPECIFIC FUNGUS PANDORA NEOAPHIDIS AND THE PEA APHIDACYRTHOSIPHON PISUM AT REGIMES OF VARYING TEMPERATURE AND PHOTOPERIOD SIMULATING VARIABLE SEASONAL PATTERNS

Feng Mingguang T. J. Poprawski

1998, 41 (2): 145-152.

Abstract （9641）

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The interaction between the aphid-specific entomophthoralean fungus, Pandora neoaphidis, and the pea aphid, Acyrthosiphon pisum, was investigated in computercontrolled growth chambers at regimes of varying temperature and photoperiod simulating different seasonal patterns in an attempt to reveal the potential preadapting behaviorof the fungus for overwintering. Based on the fitting of the time-dose-mortality model to the experimental data, the time-dose effect pattern was found to be similar between the photoperiods of 16 ∶ 8 and 11: 13 (L ' D) at 20℃, but was significantly different between the constant and daily varying temperatures (5.4-18.9℃ at the rate of 0.56℃per 30 min) and also between the above photoperiods at the same varying temperature.With the varying temperature treatment, the mean incubation time of the fungus on the host (I. E. , mean lethal time postinoculation) was 15.14 d for 8 h of light, 15.19 d for 9.5 h, 11.79 d for 11 h, 13.33 d for 11.5 h, 11.73 d for 12 h, and 9.21 d for 16 h, respectively. This displayed a significantly negative correlation ( a=15.58, b=- .93, r ²=0.78, p＜0.01). However, the mean incubation periods were nearly identical for 11and 16 h of light at 20℃ (5.85 d and 5.97 d). Abnormal hyphal bodies of the fungus were not found during microscopic examination of all cadavers from all the regimes of temperature and photoperiod. The fungus maintained its infectivity to the host at all theregimes considered and had no preadapting behavior to overwintering. However, the short photoperiods were found to decrease the mean incubation time at the varying temperature that simulated a late autumn or early winter pattern.

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Phagocytosis, nodulation and encapsulation in cellular immune responses in insects

WU Shan， LING E J

2009, 52 (7): 791-798.

Abstract （7994）

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Cellular immunity that includes phagocytosis, nodulation and encapsulation mediated by hemocytes is a very important part of the innate immune system in insects. In this article we reviewed the current understanding of cellular immune responses in insects. We summarized the hemocyte types involved in cellular immunity, some cellular receptors that recognize different microbes and multicellular parasites, and some enzymes and chemicals that can affect the immune activity. We also discussed the modes of hemocyte-mediated phagocytosis and the morphological change of hemocytes during the progress of nodulation and encapsulation.

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The aggregation pheromones of insects

JIANG Yong ^1,2,LEI Chao-Liang ², ZHANG Zhong-Ning ^1*

2002, 45 (6): 822-832.

Abstract （7898）

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Aggregation pheromones are important semiochemicals in insects that play a key role in mating and other social behavior. Many chemicals, including hydrocarbons, alcohols, aldehydes, ketones, esters, acids, anhydrides, amines, and nitriles, have been identified as insect aggregation pheromones, however, understanding of their potential utility in pest management is still limited. Aggregation pheromones have been found in eggs, larvae and adults, however, some volatiles from host plants have been regarded as pheromone components. Aggregation pheromones of the same species in different stages of the life-cycle can be distinct, and the same semiochemical may induce different behavior in different developmental stages or physical states. Nevertheless, the aggregation of insects can be regulated by semiochemicals such as kairomone, sex pheromone and alarm pheromone. Understanding of insect aggregation pheromones is still inadequate and determining the precise function of these chemicals requires further research.

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Purification of antimicrobial peptide MDL-1 from Musca domestica larvae and its effect on Escherichia coli ultrastructure

GONG Xia, SHI Yong-Hui, LE Guo-Wei ^*

2004, 47 (1): 8-13.

Abstract （7643）

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The immunized hemolymph was produced from Musca domestica larvae by the inducing of challenging injury and bacteria. The antimicrobial peptide was purified by means of boiled water bath, dialysis and concentration, Tricine-SDS-PAGE preparation, retrieval and renaturation of peptides. The results of amino acids an alysis showed that the molecule weight of the antimicrobial peptide 1 (MDL-1) was 6 200 D. It contained abundant Gly and alkaline amino acids, which had potential activity against Gramnegative bacteria, Escherichia coli. Preparative electrophoresis was an effective way to produce antimicrobial peptides. The anti microbial mechanism of MDL-1 was tentatively studied. The results showed that MDL-1 caused a series of pathological changes on E. coli. MDL-1 was located on the plasma membrane observed with transmission electron microscopy. MDL-1 adhered to bacterial cells by static electricity gravitation in the early stage, and then it was observed that MDL-1 affected on the plasma membrane, disturbed the ordered arrangement of membrane lipid and changed permeability of plasma membrane, with irregular holes appearing in the plasmalemma and cytoplasmic contents of the cells leaking out. Finally, the affected bacteria disintegrated into small fragments and died.

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Expression of the antifreeze protein gene of a pyrochroid beetle Dendroides canadensis in prokaryote and detection of the protein biological activity

LIU Zhong-Yuan, ZHANG Fu-Chun ^*, WANG Yun, LU Guo-Dong

2005, 48 (2): 179-183.

Abstract （7424）

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In order to express a pyrochroid beetle Dendroides canadensis antifreeze protein in E. coli BL21 and to investigate the properties of recombinant antifreeze protein, the D. canadensis afpgene was synthesized, cloned into the pGEX-4T-1, and transformed into E. coli BL21 The optimal inductive condition was selected by different experimental approaches. The results of SDS-PAGE analysis indicated that the antifreeze protein was expressed successfully in E.coli BL21 The expressed antifreeze protein, existing in the soluble and fusion form, with the molecular weight of about 40 kD, could increase low temperature resistance of bacteria as shown by the biological activity detection.

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Mapping and expression analysis of GOBP/PBP subfamily gene cluster during pupal and adult stages of the silkworm, Bombyx mori

ZHANG Sheng-xiang

2010, 53 (10): 1069-1076.

Abstract （7164）

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Odorant binding proteins (OBPs) in insects play a primordial role in foraging, courtshipping, multiplying, and chemical communication with the environments. General odorant binding protein/pheromone binding protein (GOBP/PBP) is an important monophyletic group of Lepidoptera OBP family. We analyzed the GOBP/PBP in the silkworm Bombyx mori, the model organism of Lepidoptera, using chromosome mapping and semi-quantitative RT-PCR for further understanding of the expression and function of GOBP/PBP. Chromosome mapping showed that these genes were organized in the nscaf3052 of chromosome 19 in the form of gene cluster, with similar gene structure and identical transcription direction, suggesting that they were originated from the duplication of homologous genes and probably possess functional similarity. Analysis of the expression profiles in different tissues of males and females during pupal and adult stages revealed that these genes possessed conspicuous temporal and spatial expression differences (P<0.05), the highest relative expression level occurred in the antenna, and lower relative expression levels in other most non-olfactory tissues without significant sex differences. The results suggest that these genes may have other functions undiscovered besides olfactory-related function.

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Interactions between the parasitoid Lysiphlebus japonicus Ashmead and its ho st Aphis craccivora Koch: host-stage selection and its effect on development

GAN Ming ^1,2, MIAO Xue-Xia ¹, DING De-Cheng ^1*

2003, 46 (5): 598-604.

Abstract （6850）

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Host-stage selection of Lysiphlebus japonicus Ashmead, a parasitoid of Aphis craccivora Koch and the effect of host stage being parasitized on the parasitoid development and fecundity were investigated at (25±1)℃. When aphids of mixed stages were provided, the parasitoid showed a preference for younger aphids to parasitize. The relative parasitism on the 2nd instar aphids was the highest (26.4%), followed by 1st instar aphids (20.6%), and rather low on the adults. The development of the aphids was delayed after being parasitized. The durations of the 1st, 2nd and the 3rd instar of the hosts significantly prolonged when 1st instar aphids were parasitized，and those of the 3nd and 4th instar were also markedly extended after alate were parasitized. However, no obvious influence on development of apterae and alate was observed after they were parasitized. The life span of the adults of the aphids parasitized at various nymphal stages sharply shortened. All of the parasitized 1st instar aphids turned to mummies before the adults. The fecundity of the adults from younger aphids parasitized distinctly declined in comparison with the control adults. Immature stage of the parasitoid In 2nd instar of the hosts developed the fastest with duration of 194.10h, and the slowest of 215.80 h in 1st instar of the hosts.Total contents of protein and glycogen in A.craccivora of different stages were also assayed.

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Effects of parasitization by Tetrastichus brontispae (Hymenoptera: Eulophidae) on immunoreaction of the coconut hispine beetle, Brontispa longissima (Coleoptera: Chrysomelidae)

LIU Kui

2008, 51 (10): 1011-1016.

Abstract （6613）

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For evaluating the effects of parasitization by Tetrastichus brontispae on immunoreaction of Brontispa longissima, the changes of total number of hemocytes, the percentage of spread plasmatocytes, the rate of melanization, phenoloxidase activity and hemagglutin activity in the parasitized Brontispa longissima pupae were measured. The results indicated that compared with the unparasitized pupae, the parasitization by the parasitoid resulted in a significant decrease in the total number of hemocytes and the spread percentage of plasmatocytes at 2 d post parasitization and a significant increase in the parasitized pupae at 4 d post parasitization. The rate of melanization in the hemolymph in the parasitized pupae was higher than that of the unparasitized pupae during 0 . 5-2 d post parasitization and decreased to 0 in 3-4 d post parasitization. The phenoloxidase activity in the hemolymph in the parasitized pupae increased significantly at 0 . 5, 1 and 4 d post parasitization. A peak of the hemagglutin activity appeared at 2 d post parasitization in the parasitized pupae, which decreased to the lowest level at 1 and 4 d post parasitization. The results suggest that the parasitization by Tetrastichus brontispae may result in irregular changes of immunoreaction of its host Brontispa longissima.

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Effects of tannic acid on the development of larvae of the fenvalerate-resistant and susceptible strains of Culex pipiens pallens (Diptera: Culicidae)

ZHANG Shi-Miao, MO Jian-Chu, CHENG Meng-Lin, XUE Zhi-Hui, SHEN Li-Feng, CHENG Jia-An

2005, 48 (6): 886-891.

Abstract （6597）

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The tannic acid is one of plant allelochemicals. In order to evaluate the potential of tannins in the larval control of noxious mosquitoes, the toxicity of tannic acid to 1st－4th instar larvae of the fenvalerateresistant and susceptible strains of Culex pipiens pallens was investigated in the laboratory, and the impact of tannins on the development of larvae was also observed. The results indicated that the larvae of the susceptible strain was more sensitive to tannins than that of the fenvalerateresistant strain, and the sensitivity of the former to tannins was 6.4, 4.9, 4.7 and 2.0 times as high as that of the latter for 1st－4th instar larvae, respectively. Among larvae of all instars of the two strains, the first instar larvae were always the most sensitive to tannins, while the third instar larvae appeared to be the most insensitive. In the solution of 1 000 mg/L tannins, the survival rate of larvae of the two strains declined with the rearing time. The survivors of larvae exposed to 100－500 mg/L tannic acid solutions had slower development than the control larvae in both strains, and the developmental duration from the first instar to pupation delayed 34.5－38.3 h for the susceptible strain and 59.2－93.4 h for the fenvalerate-resistant strain. Furthermore, the developmental duration of 1st－4th instar larvae were significantly different (P<0.05) between the control and the treatment when the concentration of tannic acid for the treatment was 125 mg/L in the susceptible strain and 250 mg/L in the fenvalerate-resistant strain. However, treating the first instar larvae of the two strains with 100－250 mg/L concentrations of tannic acid had no influence on the pupation, emergence and adult sex ratio of the survivors. The results suggested that tannic acid affected mainly the developmental duration of C. pipiens pallens larvae and the degree of influence was related to the susceptibility of larvae to fenvalerate. 

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IDENTIFICATION OF SOME CHINESE ARMYWORMS

CHEN YUNG-LIN

1963, 12 (1): 10-20.

Abstract （6425）

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The relation of interaction between insects and plants to evolution

QIN Jun-de, WANG Chen-zhu

2001, 44 (3): 360-365.

Abstract （6232）

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Insects and plants are important components of the terrestrial biocommunities on the globe; living together they perform diversified interactions including patterns of insectan trophic activity and mode of pollination. In this paper the relationship between these interactions and evolution is discussed. According to the breadth of hostplant range, phytophagous insects are usually classified into specialists (with narrow host range) and generalists (with broad host range). If the seemingly advantage to feed on many different plants by insects is considered, the generalists would be regarded to attain a higher level of evolution. However, a careful examination on the biocommunities in nature usually gives rise to the hard question of why there are so many specialists among insect herbivores. The explanation seems to lie in the higher efficiency of hostplant foraging and the ease of escaping or avoidance from natural enemies in the specialists. Plant adaptation to insect herbivory presumably would cause corresponding reactions in insects, leading to the proposals of coevolution theory. For hostplant selection by insects, several theories are proposed to clarify the present status as paired reciprocal, diffused and community coevolutions. The precedence of diversification of secondary metabolic chemicals in plants and the mutability and adaptation in insect sensory function as well as learning and memory also lead to the proposal of the theory of sequential evolution or colonization. In pollination the mutualistic adaptations between flowers and pollinator insects are manifested in convincing examples including the changing signalling cues from flowers as scents, colors in different plant species, and the blooming schedules, and the behavioral responses and structural modifications of the pollinator insects.

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Baculovirus chitinase: Advances in research and application

LIU Yan-He

2008, 51 (4): 430-436.

Abstract （6168）

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The chitinase gene of baculovirus is the gene that is not essential for the virus replication. It is expressed in the late phase of the virus replication in insect cells, and it is highly conservative. The chitinase contains three functional regions: N-terminal secretion signal peptide, central active region that includes the active site of family 18 chitinases and a functional C-terminal endoplasmic reticulum (ER)-retention sequence. The enzyme possesses high performance of both exo- and endo-chitinase activity, which can hydrolyze inherent chitin in insect body, and promote liquefaction of the host after death. The chitinase may also serve as a molecular chaperone of pro-V-Cath, the precursor of V-Cath, for its proper folding and transportation in the ER. It has an influence on the polyhedra releasing and cell lysis. The chitinase is also relevant to the baculovirus infection. Phylogenetic analyses indicate that baculovirus acquires the chitinase gene from bacterium via horizontal gene transfer, but insect chitinase gene may directly come from baculovirus. For biological control of pests, the baculovirus chitinase can control insect pests as an insecticide, or work together with Bacillus thuringiensis or a baculovirus as its potentiator; the baculovirus chitinase gene can also be introduced into plants to get the transgenic plants that increase resistance against herbivorous pests and fungal pathogens without affecting non-target insects. The baculovirus chitinase ER-retention motif was deleted or modified, or heterologous chitinase was introduced into the baculovirus genome, which made the biological activity of the recombinant virus enhanced. Deletion of the chitinase and v-cathepsin genes from the baculovirus expression vector through genetic engineering has a positive effect on the integral membrane and secreted proteins.

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Species identification of Noctuidae moths (Insecta: Lepidoptera) from Baihuashan, Beijing, China with DNA barcoding

YANG Cong-Hui, HAN Hui-Lin, CHI Mei-Yan, JIN Qian, WU Chun-Sheng, ZHU Chao-Dong, ZHANG Ai-Bing

2012, 55 (9): 1082-1092.

Abstract （6131）

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To explore the feasibility of DNA barcoding in the identification of Noctuidae moths, the COI genes of 75 samples belonging to 43 species from Noctuidae in Baihuashan, Beijing, were amplified using universal barcoding primers. The intraspecies and interspecies genetic distances were calculated using the Kimura-2-parameter model, the phylogenetic trees were reconstructed by neighbor-joining (NJ) and maximum parsimony (MP) method, and the identification of MOTU was performed using sequence divergence threshold technique. The results showed that all of Noctuidae species were successfully distinguished by the phylogenetic tree. The average intraspecific genetic distance (0.02%) was much less than the average interspecific genetic distance (11.28%). Seventy-five Noctuidae samples were divided into 42 MOTUs based on 1% sequence divergence threshold and the accuracy rate was 95%. Most of MOTUs (41/42) were classified into their corresponding morphospecies with only one exception (MOTU04). The study indicates that the species from Noctuidae family can be well distinguished with the commonly used COI barcodes, which are potentially well utilized in moth species identification.

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RNA interference of FTZ-F1 gene mediated by bacterially expressed dsRNA in the silkworm, Bombyx mori

WANG Gen-Hong, ZHU Hui-Min, LUO Hui-Song, WANG Ke-Ke, YANG Xiao-Bo, JIANG Liang, XIA Qing-You

2011, 54 (5): 596-601.

Abstract （6130）

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We developed a method of RNA interference based on bacterially expressed dsRNA in the silkworm, Bombyx mori. By inserting the target, FTZ-F1 gene fragment, between the two convergent T7 polymerase promoters in opposite orientation in L4440 dsRNA expression vector, the recombinant plasmid was formed. Then the recombinant plasmid was transformed into Escherichia coli HT115, an RNase-III deficient strain. dsRNA was extracted from the E. coli HT115 after being treated with isopropyl-β-D-thio-galactopyranoside (IPTG). RNAi treatment was performed by injecting the extracted dsRNA (25 μg) into body cavity of silkworm at the 7th day of 5th instar. The RNAi of FTZ-F1 gene resulted in 85% of the insects with delay of pupal metamorphosis and disablement in pupa formation. Real-time quantitative PCR analysis revealed that the expression of FTZF1 gene was specially inhibited after the insects were treated with dsRNA of FTZ-F1 gene. The results suggest that the bacterially expressed dsRNA has potential to be used in silkworm functional genome analysis in an economical and efficient way.

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Economic value of insect pollination for fruits and vegetables in China

AN Jian-Dong, CHEN Wen-Feng

2011, 54 (4): 443-450.

Abstract （6068）

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Insect pollinators play an important role in agricultural production, especially for fruits and vegetables. However, there is now mounting evidence of pollinator decline in many countries all over the world and it is important to assess its potential impact on crop production. To assess the situation of insect pollinators in China, we first examined the changes in the number of honeybee colonies and the area planted with fruits and vegetables over the past half century. We then used the bio-economic approach, based upon the pollinator dependency of 44 crops used directly for human food, to assess the value of insect pollination for Chinese fruits and vegetables. The stock of honeybee colonies in China had increased by 161% between 1961 and 2009, while the area of fruits and vegetable cultivation had increased by 472%, and their production had increased by 833%. The growth in yield of insect-pollintated fruits and vegetables in China is closely related to the growth in the cultivated area ( r=0.995, P<0.01), and is also related to the increase in the number of honeybee colonies ( r=0.804, P<0.01). The total economic value of insect pollination of Chinese fruits and vegetables amounted to 52.2 billion US dollars in 2008, which represented 25.5% of the total production value of the 44 crops produced in China. In production value, apples, watermelons, pears, mangoes and plums are the leading crops that depend on insect pollination. Insect pollination thus represents a substantial economic factor for fruits and vegetables production in China, and Chinese fruits and vegetables have a higher economic vulnerability ratio to pollinators than the world’s average level of 15.9%. With the continuing increase in the area planted with fruits and vegetables, the need for the service provided by insect pollinators in China is likely to continue to increase.

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Structure and function of sterol carrier proteins in insects

ZHANG Li-Li, GUO Xing-Rong, FENG Qi-Li, ZHENG Si-Chun

2011, 54 (4): 457-466.

Abstract （5978）

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In insects, cholesterol is not only one of the main components of cell membranes, but also a precursor of ecdysone biosynthesis. However, because insects lack two key enzymes for cholesterol biosynthesis, they can not autonomously synthesize cholesterol from simple compounds and therefore have to obtain sterols from their diet. Insects must convert food sterols into cholesterol to meet the requirements of growth, development and reproduction. Sterol carrier proteins (SCPs) are main transport proteins for sterol absorption and transport in insects. It is critical to study the relationship between structure and function of SCPs for understanding the roles of SCPs in sterol transport. In this review, recent progress in the study of the structure, expression and distribution of SCP genes and proteins, post-translation modification, crystal structure, ligand-binding specificity and possible absorption and transport pathways of insect SCPs was summarized and the potential of using SCPs as a molecular target for pest insect control was also discussed. Studies indicate that transcript expression of SCP genes and post-translation modifications of SCP proteins vary depending on different species. In dipteran insects such as Aedes aegypti and Drosophila melangoster SCP-x gene encodes SCP-x and SCP-2 proteins, while there are additional SCP-2 genes and SCP-2-like genes encoding SCP-2 and SCP-2-like proteins, respectively. In lepidopteran insects such as Spodoptera littoralis, Spodoptera litura and Bombyx mori, the transcript expression and translation processes of SCP-x gene are similar to those in vertebrates, in which SCP-2 protein is produced after post-transcription and translation modifications of a unique SCP-x gene. SCP-x and SCP-2 proteins are localized in peroxisomes. SCP-2 protein consists of 5 αhelixes and 5 β-sheets and the α5-helix appears to impact the binding of the protein to substrates. SCP-2 protein can bind with different affinity to cholesterol, cholesterol derivatives, fatty acids, acyl-coenzyme A and phospholipids. Over-expression of SlSCP-x and SlSCP-2 genes can increase the uptake of cholesterol into cells and RNAi inhibits the expression of SlSCP-x and SlSCP-2 genes in S. litura larvae, resulting in a decrease in cholesterol level in the hemolymph and a delay in larval growth and pupation.

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Purification of destruxins produced by Metarhizium anisopliae and bioassay of their insecticidal activities against grubs

HU Qiong-Bo, REN Shun-Xiang, LIU Shu-Yan

2007, 50 (5): 461-466.

Abstract （5977）

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Five crystal destruxins were purified from the fermentation broth of Metarhizium anisopliae var. anisopliae strain MaQ10 via preparative HPLC and re-crystalization, which were classified to destruxin A, B, C, E and A₂, respectively. Contact toxicities of destruxins A and B against the grubs Exolontha serrulata (Gyllenhall) and Holotrichia ovata Chang were bioassayed by immersing the insects in aqueous dilutions. The results indicated that at 96 and 120 h after treatment, the LC₅₀s of destruxins A and B were estimated as 78 . 1571 mg/L and 88 . 7562 mg/L towards E. serrulata and 66 . 5308 mg/L and 79 . 4309 mg/L towards H. ovata, respectively. At the concentration of 300 mg/L, the LT₅₀s of destruxins A and B were 13 . 4159 h and 10 . 5331 h towards E. serrulata, and 13 . 6399 h and 9 . 9451 h towards H. ovata, respectively.

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Extraction of catnip essential oil components and their repellent activity against Aedes albopictus and Culex pipiens pallens

HAO Hui-Ling, DENG Xiao-Jun, DU Jia-Wei

2006, 49 (3): 533-537.

Abstract （5969）

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Nepetalactone, the primary component of catnip oil, were extracted by the using method of simultaneous distillation extraction and separated by using silica gel chromatography column. To compare the repellency of nepetalactone and DEET on mosquitoes, topical bioassay method on the skin and a cage olfactometer were employed to assess the effective protection time and the spatial repellency. The results showed that essential oil of catnip was comprised of 55% nepetalactone, with the constitution of 32% Z, E-nepetalactone and 23% E, Z-nepetalactone. Evaluated by using laboratory efficacy criterions and bioassay method of public health insecticides for pesticide registration, the results showed that the protection time for DEET and nepetalactone against Aedes albopictus was 9.6±0.2 h, and 2.2±0.2 h respectively, and against Culex pipiens pallens was 11.5±1.5 h and 4.3±0.8 h respectively. When used alone, nepetalactone attracted mosquitoes to the trap of the olfactometer, however, when mixed with human odor or a L-lactic acid dichloromethane solution, nepetalactone inhibited the attractiveness obviously. Nepetalactone exhibited a spatial repellency, but was not an ideal topical repellent. DEET did not have the attractiveness to mosquitoes, and did not exhibit inhibition on L-lactic acid dichloromethane solution too, but enhanced the attractivity of human odor to mosquitoes.

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A gynandromorphy of Polistes nimphus(Christ, 1791) (Hymenoptera: Vespidae: Polistinae) in China

YUAN Feng, ZHAO Y H, ZHANG Y Z, ZHU C Dong

2009, 52 (9): 1055-1057.

Abstract （5870）

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This note reports the occurrence of gynandromorphism in Polistes nimphus (Christ, 1791) in China. External features of the insect are presented. The insect was collected in Mt. Donglingshan, Mentougou, Beijing. The specimen studied is deposited in the Institute of Zoology, Chinese Academy of Sciences.

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Cloning and differential expression of Bombyx mori carboxylesterase gene

GAO Gui-Tian, CHEN Ke-Ping, YAO Qin, WANG Lin-Ling, CHEN Hui-Qing

2006, 49 (6): 930-937.

Abstract （5852）

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Total RNA was isolated from the fully resistant silkworm ( Bombyx mori) strain Qiufeng against BmDNV-Z, the highly susceptible silkworm strain Huaba and near-isogenic line BC ₈ which was bred by using Qiufeng to cross with Huaba followed by successive backcrossing to Huaba till the eighth generation, respectively, and then subjected to fluorescent differential display reverse transcription PCR (DDRT-PCR). A full-length cDNA of B. mori carboxylesterase was obtained. Its expression in the midgut of the susceptible strain and the resistant strain against BmDNV-Z was analyzed by real-time fluorescence quantitative PCR at 12 h, 36 h and 72 h after administration with BmDNV-Z. The results showed that: (1) cDNA quantity of carboxylesterase in the midguts of the resistant strains reached the peak 12 h after infection. The cDNA quantity in the resistant strains BC ₈ and Qiufeng were 17.714 and 3.602 times respectively that in the susceptible strain Huaba. (2) Within the same strain, there existed a remarkable difference in the detected carboxylesterase cDNA quantity at 12 h between the infected group and the control group. The expression in the resistant strains BC ₈and Qiufeng were 15.08 and 3.39 times respectively that of the control group. On the other hand, the expression of carboxylesterase was quite low in the susceptible strain Huaba of both the infected group and the control group. (3) The expression of carboxylesterase varied at different time after infection. Expression in the resistant strains BC ₈and Qiufeng reached its peaks 12 h after infection, remarkably higher than those at 36 h and 72 h. There was no significant difference of the expression in the susceptible strain Huaba infected for 12 h, 36 h and 72 h. The results suggested that the expression of carboxylesterase in B. mori might be related to its resistance against DNV.

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Toxicity and action mechanism of tebufenozide and its derivative 0593 to silkworm (Bombyx mori)

SI Shu-Ding

2008, 51 (11): 1157-1163.

Abstract （5844）

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In order to definite the toxicity of tebufenozide derivative 0593 to silkworm Bombyx mori, we detected the toxicity of tebufenozide and its derivative 0593 to B. mori with food intake method, observed the growth and development of B. mori at their respective sublethal concentration, and determined their effects on endogenous protective enzymes in B. mori larvae. Based on the experimental results, we primarily discussed the action mechanism of ebufenozide derivative 0593. The results showed that the LC₅₀ of tebufenozide and its derivative 0593 to 2nd instar larvae of B. mori were 1 . 2863 mg · L^-1 and 0 . 3364 mg · L^-1 after 96 h exposure, respectively, and both were of high toxicity. At the sublethal dose, the growth and development of B. mori had been obviously affected, which could shorten larval period by 0 . 5 ～ 2 d. Compared with control, larval weight during molting stage, whole cocoon weight, pupal weight and pupation rate decreased of the treatments dramatically. The PPO activity in 4th instar larvae of B. mori was activated at 6 h after treatment, and then inhibited at 12 h after treatment. Both tebufenozide and its derivative 0593 significantly activated the chitinase activity in 4th instar larvae of B. mori. 0593 showed more significant effects on endogenous protective enzymes than tebufenozide. These results indicate that tebufenozide and its derivative 0593 belong to high toxicity grade to B. mori, and have adverse effects on its development and endogenous protective enzymes. So they are not suitable to be used in and around mulberry fields.

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Morphological adaptation of aphid species on different host plant leaves

FANG Yan, QIAO Ge-Xia, ZHANG Guang-Xue

2011, 54 (2): 157-178.

Abstract （5762）

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Morphological adaptation of insects to their host plants is an important part of the relationship between the two types of organisms. This paper dealt with herbivorous aphids to study their morphological adaptation on different host plant leaves. Twenty-six aphid species which feed on the leaves of 7 genera host plants belonging to 4 families (Poaceae, Salicaceae, Fagaceae, and Pinaceae) were studied. Based on alate viviparous females and apterous viviparous females, 37 morphological characters were compared and measured by using light microscope. Then the characters were statistically analysed. Based on the clone means, with the variables such as ultimate rostral segments, tarsi and claws which are related to aphid feeding behavior and adhesion on the surfaces of plants, three clustering dendrogram (alate viviparous female, apterous viviparous female, all morph) were output and mapped with host plant families and genera. The results indicated that some characters of the aphids, such as body, siphunculi and antennae, were different among different aphid families, but some of them, such as the ultimate rostral segments, tarsal segments Ⅰ, tarsal segments Ⅱ and claws, varied among different host plant families. The variations of morphologies within species were within a range with their CV (coefficient of variation) between 1.89% and 26.08%. The clustering analysis showed that the aphids were divided into the clusters which were corresponding to certain host plant family/genera; and the positions of Doraphis populi, Epipemphigus imaicus and Pemphigus matsumurai were special, because the first is the secondary host-plant morph and the latter two are the gall makers. The results suggest that the distinct separation of the aphid species with respectively different morphological character variations is corresponding to different host plants whose surface structures are diverse. These prove morphological adaptation of aphids to host plants.

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Deposition modes, components and functions of secretions associated with oviposition in insects

JIN Feng, JI B Z, LIU S W, TIAN L, GAO J

2009, 52 (9): 1008-1016.

Abstract （5736）

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Oviposition is the important life phase in insects. Before, during or after egg-laying, most females deposit secretions near eggs. These secretions may serve as egg-adhesive substances or egg-cover substances and protect eggs and early larvae. Some insects also use the secretions as egg marking pheromones which can mediate intra- and inter-specific competition of natural resources. Considering the specific physiological and ecological functions and the influence on population densities, the deposition of secretions associated with oviposition is an evolutionary adaptation. In this article, we reviewed the deposition and physical characteristics of secretions during oviposition in various insects, and the chemical components, possible functions and excretion organs of the sectetions and the microbe species in them were also summarized.

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STUDIES ON THE LONGEVITY OF ADULT AEDES(S.) ALBOPICTUS (SKUSE):THE LONGEVITY OF CAGED FEMALES UNDER LABORATORY CONDITIONS

GAO JU-ZHEN, ZHEN ZHAO-YU, XUE JING-MIN, HUANG PIHG-YI, ZHAO JUN-PING, CAO NIAN-HOU

1984, 27 (2): 182-188.

Abstract （5734）

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Characterization, classification and phylogenetic analysis of long terminal repeat retrotransposons in the silkworm, Bombyx mori

XU Hong-En, HAN Min-Jin, ZHANG Hua-Hao, SHEN Yi-Hong, XIANG Zhong-Huai, ZHANG Ze

2011, 54 (11): 1211-1222.

Abstract （5712）

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In eukaryotes, transposable elements (TEs) constitute a large fraction of a genome. TEs are usually classified into two classes based on their transposition mechanisms. ClassⅠ elements use an RNA-mediated mode of transposition, while classⅡ elements (transposons) use a DNA-mediated mode of “cut and paste” transposition. ClassⅠ elements are further divided into two subclasses: the elements that are characterized by long terminal repeats (LTR retrotransposons) and the elements that lack terminal repeats (non-LTR retrotransposons). In order to reveal the classification and evolution of LTR retrotransposons, we identified LTR retrotransposons in the domesticated silkworm ( Bombyx mori) using de novo and homology search approaches and found 38 families in the silkworm genome, of which 6 families are novel. The sequences of these families constitute 0.64% of the whole genome, which is much less than that previously reported. We also found that 26 of 38 families have EST evidence, implying that they had potential activity. Then RT-PCR was performed to validate the expressions of 11 families (6 families have EST evidence and 5 families have no EST evidence), and the results showed that these 11 families were expressed in some tissues, further supporting their transcriptional activities. Based on these results, we speculated that most of LTR retrotransposon families in the silkworm genome have potential activity. We estimated the insertion time of LTR retrotransposons, and found that most of them were inserted into the silkworm genome within the past million years. A comparison of Ty3/Gypsy superfamily in Drosophila melanogaster, Anopheles gambiae and B. mori showed that this superfamily experienced different expansion patterns. Given the importance of LTR retrotransposon activity in the evolution of other genomes, our results provide some insights into the roles of LTR in insect genome evolution.

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The structure and distribution of Pheidole yeensis nests

ZHANG Zhi-Ying ¹, LI Yu-Hui ², ZHAO Zhi-Mo ³

2003, 46 (1): 40-44.

Abstract （5688）

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Codariocalyx motorius (Houtt.) Ohashi grows as a common perennial pioneer plant in areas of slash and burn cultivation in the tropical and subtropical mountains of Yunnan Province, China. There is mutualism between the ant, Pheidole yeensis and C. motorius. The plant provides the ant with food, and the ant carries and disperses the seeds of the C. motorius. The structure and distribution of Pheidole yeensis nests in Yunnan Province was investigated in 2000.The results show that P. yeensis mainly builds nests in soil at an altitude of 1 000-1 200 m. Nests can extend down to a depth of 50 cm with the usual depth being 20-40 cm. The number of the ants per nest ranged from 2 000 to 3 000, with the maximum being more than 10 thousand. In fields that had been abandoned for 2-3 years at an altitude of 1 000-1 200m, most nests were found on western slopes, southern slopes having the next highest nest density, and northern slopes the least. The number of nests was highest in fields that had been abandoned for 2-3 years with the next highest abundance recorded in corn and peanut fields and the lowest in forest. The spatial istribution of P. yeensis nests was regular, but ant colonies repelled one another.

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Insect genomes and their sizes

XUE Jian, CHENG JA, ZHANG CX

2009, 52 (8): 901-906.

Abstract （5679）

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The difference of genome size between different insects is due to varieties of duplication of the genome sequence in the amplification, deletion and differentiation. Fifty-nine insect species have been included in genome sequencing projects, whole-genome sequences of six insect species, i.e., Drosophila melanogaster, Anopheles gambiae, Bombyx mori, Apis mellifera, Aedes aegypti and Tribolium castaneum, have been reported. The sizes of 725 insect genomes have been estimated, ranging from 0.09-16.93 pg (88-16 558 Mb). The estimation methods for insect genome size are introduced, and the variation of insect genome sizes and its significance are also discussed.

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Advances in the research on the nervous system of the silkworm, Bombyx mori

YU Qi, ZHOU Qi-Sheng, LIU Qing-Xin

2011, 54 (10): 1172-1180.

Abstract （5604）

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The silkworm, Bombyx mori, has a ventral nerve cordtype nervous system, which is more simple in structure than that of vertebrates; however, the simple system controls the complex behavior of the silkworm. Therefore, B. mori is an ideal model animal for neurobiology study. The silkworm nervous system, including the central nervous system, the peripheral nervous system and the sympathetic nervous system, plays a role in the regulation of sight, smell, feeding, cocooning, mating, excretion and other life activities of the silkworm by transferring signals. The genes coding for neurotransmitters, e.g., acetylcholine, γ-aminobutyric acid and dopamine, and neuropeptides, e.g., prothoracicotropic hormone (PTTH) and diapause hormone (DH), were found in the nervous system of the silkworm. The development of the silkworm nervous system is regulated by a variety of genes and MicroRNA, such as bmo-miR-92. At present, the main research methods for silkworm nervous system include electroantennogram, immunocytochemistry, transgenic methods, neuroinformatics, and three-dimensional reconstructions. The research on silkworm nervous system will help to illuminate the signal transmission mechanisms of nervous system and the formation mechanisms of biological neural networks.

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Morphological and biological observations on Stomphastis thraustica Meyrick (Lepidoptera: Gracillariidae), a leaf miner of Jatropha curcas

2009, 52 (2): 228-233.

Abstract （5574）

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A leaf miner of Jatropha curcas L., Stomphastis thraustica Meyrick (Lepidoptera: Gracillariidae), was newly found in China. The morphology, development and life history of the pest were studied both in fields and laboratory. The color, width and length of the pest at each stage were reported in details. The 95.54 percent of the larvae (n=426) climbs out to make cocoon from 10:00 am to 18:00 pm. The 89.19 percent of the eclosion (n=111) takes place from 20:00 pm to 6:00 am. Mating occurs in the early morning and will lasts 30-210 minutes. The 87.53 percent of the eggs are laid during the 20:00 pm to 6:00 am. The adult likes to oviposit in the concave near the leaf nervure. The 66.77 percent (n=8 266) of the eggs are laid on the back of the leaf. Each female can lay 60.03 eggs on average. The moth appears throughout the year in Panzhihua and has to endure the dry season in the adult from February to May. The moth has over ten generations per year in this region and the generations overlap. The development durations of different stages were investigated at natural temperature averaged 25.15℃ in June in fields. The duratin of a whole generation is 18 to 20 days including 3 to 4 days for the egg stage, 1 day for the first instar, 1 to 2 days for the 2nd instar, 1 to 2 days for the 3rd instar, 1 to 2 days for the 4th instar, 2 to 3 days for the 5th instar, 1 day for prepupa, 4 to 6 days for pupa, and 1 day for preoviposition.

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Biological characteristics of the ber fruit fly, Carpomya vesuviana (Diptera: Tephritidae)

HU Long-Sheng, TIAN Cheng-Ming, ZHU Yin-Fei, ZHOU Zhong-Zan, REN Ling, QI Chang-Jiang

2013, 56 (1): 69-78.

Abstract （5564）

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The ber fruit fly, Carpomya vesuviana Costa, is currently listed as a quarantine pest which is prohibited into China, and its occurrence has led to disastrous damage to Ziziphus, especially its larvae feed sarcocarp, affecting the quality and commodity price of jujube products. The biological characteristics of the ber fruit fly, including eclosion, mating, oviposition and the effective accumulated temperature, were studied through field survey and laboratory observation in Xinjiang. The results showed that the process of eclosion can be divided into four stages: cracking and crawling out pupal shell, crawling around, wing stretching and flying. About 86.3% eclosion of the ber fruit fly mainly occurred from 8:00 to 11:00, and the peak time was around 10:00. The mating process lasted about 309.00±8.46 min, with the peak time occurring at 11:00-12:00 and 20:00-21:00. Oviposition consists of four stages, i.e., orientation, puncture, ovulation and ending, with the average time about 8.20±0.51 min. Fewer eggs were laid before 9:00 and after 21:00. The highest number of eggs laid per female per day was 16, the average number of eggs laid per female per day was 6-9, and 1-6 eggs were laid in each oviposition aperture. The developmental threshold temperature and effective accumulated temperature were different during each stage (egg, 13.75℃and 48.18 day-degrees; pupa, 6.38℃and 357.17 day-degrees; from egg to pupa, 8.78℃ and 283.29 day-degrees; larva, 6.39℃ and 245.61 day-degrees, respectively). This study provides basic data for further studying and sustainable control of this serious pest.

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Sequencing and analysis of the complete mitochondrial genome of the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

XU Lang, YU Dao-Jian, ZHANG Run-Jie, LI Jian-Guang, KANG Lin, CHEN Zhi-Lin, JIAO Yi

2007, 50 (8): 755-761.

Abstract （5557）

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The complete mitochondrial genome of the Oriental fruit fly, Bactrocera dorsalis is important for general molecular and evolutionary studies in Tephritidae. Via sequencing and cloning the target DNA sequences, a complete mitochondrial genome sequence of B. dorsalis from the Chinese population was determined and analyzed. The results indicated that the complete mitochondrial genome of B. dorsalis is a circular molecule of 15 915 nucleotides (GenBank accession no.: DQ845759). Its overall composition is 39 . 3%A, 16 . 2%C, 10 . 2%G, and 34 . 3%T, and the gene content includes 22 tRNAs, 2 rRNAs and a long non-coding region (A+T-rich region). Seven protein genes and 13 tRNA genes are transcribed from J strand, and the other 6 protein genes and 9 tRNA genes are transcribed genes from N strand. Protein coding genes on J strand show a fairly similar A% and T%, whereas those encoded on N strand have a higher proportion of A than T. The similarity analysis of mtDNA CO Ⅰ genes between B. dorsalis and the other 14 fruit flies showed that there was a high similarity among B. dorsalis and the other species belonging to the same subgenus Bactrocera.

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Honeybee: a newly emerged model organism

2009, 52 (2): 210-215.

Abstract （5549）

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The honeybee is a group of eusocial insects with high economical and ecological value. The Honeybee Genome Project has provided a molecular basis for further researches on honeybee biological characteristics, molecular mechanism and evolution of social behavior, and thereby equipped the honeybee to be a model organism from an economic insect. We introduced the advantages of the honeybee as a model organism and its model value in some hot research fields based on its biological characteristics, such as learning and memory, labor division, caste differentiation, and immunity, etc. After summarizing the current status and prospecting the future development of biological research on honeybee at home and abroad, we appealed for interdisciplinary research on honeybees at home.

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Effects of heavy metal pollution on insects

SUN Hong-Xia, LIU Ying, ZHANG Gu-Ren

2007, 50 (2): 178-185.

Abstract （5547）

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Heavy metal pollution has become a global environmental problem and severely threatened the biological diversity and people's health. More and more attention has been paid to the potential effects of heavy metal pollution on insects as one of the important groups of global biological diversity. The accumulation of heavy metals in insects may influence their development. It has been demonstrated that insects could be contaminated by respiration, ion absorbing through integument and food intake. Excessive metal accumulation in insects could not only cause cell ultrastructure variations and genetic homeostasis alteration, but also induce cell apoptosis and influence cell viability and proliferation. But, heavy metals can be stored in insect organs with digestive, storage or excretory function in form of “granules”, and be transported into lysosomes to detoxify. Moreover, metallothionein and antioxidant enzymes also play important roles in the process of detoxification.

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THE FLIGHT CAPABILITIES OF RICE STEM BORER MOTHS TRYPORYZA INCERTULAS, CHILO SUPPRESSALIS AND SESAMIA INFERENS

SUN JIAN-ZHONG ZHANG JIAN-XIN SHEN XUE-SHENG

1993, 36 (3): 315-322.

Abstract （5547）

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Adult flight capabilities of three major rice stem borers, Tryporyza incertulas, Chilo sup=pressalis and Sesarnia inferens were determined with flight mill and computer system. The results show that the moths of T. incertulas and C. suppressalis have similar flight capability. Normal flights took place within four days after emergence, and they had no conspicuous pre-repro ductive period and calling and mating could occur whithin 24 hours after emergence. Motlhs within one day after emergence in the second phase of ovarian development had the strongest flight capability. The cumulative flight distance of a female moth was determined to be over 32 kilometers. Female moths showed longer flight duration while most of the male moths made irregular interval flights affected easilty by physical conditions. Flights of thse two species were closely related to calling, mating and ovipositlon behaviours, showing typical mating flight syndrome. Though most flights in the field were trivial, the longest dispersal distance could be over 100 kilometers. The moth of S inferens had the strongest flight capability among the three rice stem boreres and the flight distance of female and male moths were over 32 and 50 kilometers, respectively. Normal flight could occur during the first six days of adult life. The pre-reproductive period were two to three days. Adults in the second phase of ovarian development made the longest flights. Thler flight capability declined with the development of the ovaries. This species has flight capability of long distance dispersal and possesses physiological and behavioural bases of migration flight.

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Behavioural responses of Bemisia tabaci B biotype to three host plants and their volatiles

CAO Feng-Qin

2008, 51 (8): 830-838.

Abstract （5535）

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Using Y - type olfactometer, behavior response of female Bemisia tabaci B biotype to three kinds of host plants, volatile extracts, volatile reference compounds, volatile ananogues were studied, and components and contents of volatiles in different host plants were compared as well. The results indicated that: 1 ） Strong behavior selection reaction of female adults of B. tabaci to tomato leaves and cabbage leaves, and their volatile extracts occured, respectively, whereas no significant behaviour selection to the pepper leaves and their extracts were found, respectively. When odors from the three host plants and their volatile extracts were comparatively tested, the female adults showed the strongest host preference to tomato, followed by cabbage, and then pepper leaves. 2 ） There were significant difference in volatile profile, components and contents among the three host plants. Volatile quantity of tomato leaves is much more than that of cabbage leaves and pepper leaves. Main components were terpene in volatile extract of tomato (89 . 8%), but hydrocarbon in volatile extract of cabbage (53 . 0%). 3) Among eight kinds of reference samples tested, 1,8 - cineole always showed strong attractableness to female B. tabaci at five concentration levels. Eugenol, limonene, linanlool and myrcene showed strong attractableness to female B. tabaci just at appropriate concentrations. However, both α - pinene and Cis - 3 - Hexen-l - of displayed repellency to B. tabaci at high concentrations, but had no effect at low concentrations. Dodecane had no distinct effect on B. tabaci at any concentrations. 4 ） Peper plants applied with tomato and cabbage volatiles analogues, respectively, could significantly attract B. tabaci adults. However, there was no significant difference in attractableness to female B. tabaci between tomato plants applied with pepper volatiles analogues and CK. The results suggest that volatile infochemicals from host plants play important roles in orientating behavior of Bemisia tabaci B - biotype.

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Effect of different hostfruits on the cold hardiness of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

REN Lu, LU Yong-Yue, ZENG Ling, PANG Shu-Ting

2006, 49 (3): 447-453.

Abstract （5456）

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The influence of different host fruits on the cold hardiness of oriental frit fly Bactrocera dorsalis (Hendel) was evaluated in the laboratory. One day old pupae bred with 15 different melons and fruits were chosen to test for their supercooling points (SCP). Furthermore, the SCPs of 3rd instar larvae, one day old pupae, 3 days old pupae, 5 days old pupae, 7 days old pupae and 2-3 days old adults (male and female) bred with five host plants (pumpkin, tomato, citrus, guava and star fruit) were measured, and the survival of one day old pupae bred with these five plants at low temperatures was observed. The results showed that the mean SCPs of one day old pupae of B. dorsalis bred with 15 different host fruits ranged from -11.03℃ to -13.17℃. Moreover, these values were significantly different at 0.05 level, and these fed on rose apple had the highest SCP （-11.03℃）, while those fed on balsam pear had the lowest SCP （-13.17℃）. The mean SCPs of B. dorsalis at the same developmental stages bred with the five host fruits further tested were significantly different from each other ( F ₍₄ _， ₈₆₃₎＝35.6， P<0.01). The mean SCPs at different developmental stages of B. dorsalis bred with the same host were also markedly different from each other ( F ₍₆ _， ₈₆₃₎＝392.9， P<0.01), and there were notable interaction between host fruits and the fruit fly developmental stages ( F ₍₂₄ _， ₈₆₃₎＝9.4， P<0.01). There were some changes among the mean SCPs of different developmental stages of B. dorsalis. From the 3rd instar larvae to one day old pupae, the SCP values were low and there were no significant difference between them. But for the pupae of 3 days old, 5 days old and 7 days old, their SCP values decreased notably, with the lowest point -20℃; however, there were no significant difference among them. For the 2-3 days old adults (female and male), the mean SCPs increased again to -10℃. The SCP values for the 3rd instar larvae, one day old pupae and adults were significantly higher than that of pupae at other three developmental stages. In order to determine the survival response to various cold stress in different host fruits of B. dorsalis, acute low temperature (-3℃) (1-8 h) and chronic low temperature (6℃) (1-8 days) regimes were designed, the corrected survival rate of the one day old pupae fed on guava, star fruit and pumpkin were higher significantly than that of the pupae fed on tomato and citrus. By exposing them to the selected low temperatures (0℃, 3℃, 6℃ and 9℃) for 2 days, the same results were obtained. Therefore, it could be concluded that different host fruits could influence the cold hardiness of next generation of B. dorsalis, and the reason underlying this needs to be further explored.

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Roles of insect salivary components in insect-plant interactions

YIN Hai-Di, HUANG Cui-Hong, XUE Kun, WANG Rong-Jiang, YAN Feng-Ming

2006, 49 (5): 843-849.

Abstract （5448）

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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.

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Repellent activity of capsaicin and its effects on glutathione-S-transferase and Na+, K+-ATPase activity in Plutella xylostella (Lepidoptera: Plutellidae)

JI Ming-Shan

2008, 51 (10): 1039-1043.

Abstract （5425）

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The repellent activity of capsaicin against Plutella xylostella, and the effects of capsaicin on activities of glutathione - S - transferase and Na⁺, K⁺ - ATPase in the 3rd instar larvae of the moth were tested in the laboratory with conventional methods. The results showed that capsaicin had strong oviposition deterrence and antifeedant activity against P. xylostella. At a concentration of 6 . 25 × 10⁴ mg/L, the nonselective oviposition deterrence rate was 96 . 55% 24 h after capsaicin application, while the selective oviposition deterrence rate was 84 . 30%. At the same concentration, the nonselective antifeedant rate and selective antifeedant rate was 81 . 47% and 69 . 69% respectively 48 h after capsaicin application. In addition, glutathione - S - transferase and Na⁺, K⁺ - ATPase activities fluctuated after P. xylostella was treated with capsaicin for different hours. When P. xylostella was treated with 1 . 25 × 10⁵ mg/L capsaicin, the highest GSTs and ATPase activities were found at 18 h and 1 h after treatment, respectively. These results suggested that capsaicin can disturb the oviposition and feeding of the moth, and influence some enzymes in its body.

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Effects of transgenic corn hybrids expressing Bacillus thuringiensis Cry1Ab toxin on survival and growth of the beet armyworm, Spodoptera exigua (Hübner)

WANG Zhen-Ying, WANG Dong-Yan, HE Kang-Lai, BAI Shu-Xiong, LIU Hui, Cong Bin

2005, 48 (2): 214-220.

Abstract （5425）

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Effects of transgenic Bacillus thuringiensis corn on survival and growth of the beet armyworm, Spodoptera exigua (Hübner) larvae, were evaluated with laboratory bioassay and field tests. Two Bt corn hybrids of events MON810 and Bt11 expressing Cry1Ab toxin and their non-Bt controls were employed. The results showed that the neonates of the beet armyworm could not survive when fed on whorl leaves, tassels and silks separately of the two Bt corns, in laboratory bioassay. A small number of neonates could survive and develop to pupate when fed on tassels and silks of MON810 and Bt11: the pupation rate is 5.2% and 2.1% with the emergence rate of 2.1% and 1.0% on MON810 and Bt11 tassels; 1.0% and 2.1% larvae pupates without emergence on MON810 and Bt11 silks, respectively. The duration for the larvae from neonate to pupae was 17 d and 28.5 d when fed on silks of MON810 and Bt11, compared with 14.0 d and 16.0 d on the corresponding non-transgenic isogenic controls, respectively. The larvae fed on tassels and silks of Bt corns had significantly lower weights than that fed on non-Bt controls in 7 days after infestation. The weight of the larvae fed on the non-Bt control husks of MON810 and Bt11 was 27.6 and 52.9 times the weights of the larvae fed on MON810 and Bt11, respectively. Development of the beet armyworm larvae fed on Bt corn was significantly delayed. Resistance level of the Bt corn whorl tissues to the 4th instar larvae was low. No significant difference was found in the pupation rate for the 4th instar larvae fed on the whorl leaves of MON810 (71.7%) and its non-Bt control (75.0%), but otherwise for those fed on Bt11 (56.7%) and its non-transgenic hybrid (85.0%). The weights of female and male pupae and the percentage of emergence when the 4th instar larvae fed on the Bt corn were significantly lower than that fed on non-Bt controls. Larval survival rate and the percentage of injured ears when larvae fed on MON810 and Bt11 silks were significantly lower compared with non-Bt controls assayed 10 d after the inoculation of the neonates in the field tests.

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