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  • Monthly, Founded in 1950
    Supervisor:Chinese Academy of Sciences
    Sponsor:Institute of Zoology,Chinese Academy of Sciences
    The Entomological Society of China
    Domestic postal code: 2-153
    Foreign issuance code: Q61
    ISSN 0454-6296
    CN 11-1832/Q
Table of Content
20 December 2003, Volume 46 Issue 6
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  • RESEARCH PAPERS
    Ability of Ixodes sinensis Teng, Haemaphysalis yeni Toumanoff and H. Qinghaiensis Teng (Acari: Ixodidae) to transmit Borrelia garinii transstad ially
    SUN Yi, XU Rong-Man, GE Xue-Feng, LU Bao-Lin, LIU Zeng-Jia
    2003, 46(6):  667-673. 
    Abstract ( 3084 )   PDF (455KB) ( 1037 )     
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    o determine the ability of Ixodes sinensis Teng, Haemaphysalis yeni Toumanoff and H. qinghaiensis Teng to transmit Borrelia garinii as potential vector of Lyme disease in South China, transstadial transmission of the spirochetes by the three species was studied in the laboratory. Results showed that the three tick species could acquire active Lyme spirochetes by feeding on infected KM mice. However, only I. Sinensis could maintain active spirochetes during molting, with subsequent developing stages infectious to normal KM mice. H. yenI and H. qinghaiensis maintained spirochetes not longer than the period of blood digestion; after molting, no spirochetes were detected in the both species. Therefore, the possibility of either H. yeni or H. qinghaiensis to be the vector of Lyme disease was small. The successful transmission of B. garinii in I. Sinensis during both larva to nymph and nymph to adult periods in the laboratory indicated that it might be the potential vector of Lyme disease in South China.
    Physiological and biochemical changes of the silkworm, Bombyx mori infected by Cordyceps militaris
    ZHANG Jun, SONG Dun-Lun*, CHEN Jian-Xin
    2003, 46(6):  674-678. 
    Abstract ( 3141 )   PDF (264KB) ( 1285 )     
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    When the 5th instar larvae of the silkworm, Bombyx mori were infected by Cordyceps militaris conidiophore, the content of haemolymph carbohydrates, trehalose, protein and glyceride differently decreased, and the decrease of haemolymph glyceride was most obvious. The activity of haemolymph trehalase also decreased in infected silkworm. The activity of haemolymph SOD, POD and CAT were changed after the silkworm was infected. The activity of SOD increased most significantly in four days: from 441.841 U/mL to 601.255 U/mL.
    Electroantennogram responses of Sitobion avenae and Rhopalosiphum padi t o wheat plant volatiles
    LIU Yong, CHEN Ju-Lian, NI Han-Xiang
    2003, 46(6):  679-683. 
    Abstract ( 3137 )   PDF (291KB) ( 1235 )     
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    The electroantennogram (EAG) responses of alate and apterous adult aphids of Sitobion avenae and Rhopalosiphum padi to wheat plant volatiles and volatiles induced by aphid feeding were analysed. Variation of olfactory responses was also analysed. EAG responses of S.avenae to methyl salicylate, E-2-hexenal, E-2-hexenol,-6-methyl-5-hepten-2-one,-6-methyl-5-hepten-2-ol, and R. padi to methyl salicylate, E-3-hexenylacetate,-6-methyl-5-epten-2-one,-6-methyl-5-hepten-2-ol were stronger. The EAG responses to-6-methyl-5-hepten-2-one, E-2-hexenol and methyl salicylate were significantly different between alate and apterous adult aphids of S. avenae.EAG reponses to E-2-hexenol, octanal, linalol, methyl salicylate, E-3-hexenylacetate were also different between alate and apterous adult aphids of R. padi.
    Effects of tannic acid on glutathione Stransferases in Helicoverpa armigera (Hübner)
    CHEN Feng-Ju, GAO Xi-Wu*, LEI Ming-Qing, ZHENG Bing-Zong
    2003, 46(6):  684-690. 
    Abstract ( 3137 )   PDF (426KB) ( 1221 )     
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    The effects of tannic acid on the specific activity of glutathione S-transferases (GSTs) in the cotton bollworm, Helicoverpa armigera(Hübner) fed on artificial diet with tannic acid were investigated. The results showed that the specific activity of GSTs was lowest in the egg stage and highest in the 5th-6th instars of the cotton bollworm. When cotton bollworms were treated with 0.005% tannic acid, the specific activity of GSTs in the 5th and 6th instars was greatly reduced (59% and 67% of the control respectively), while it was induced in the 3rd instar and not different from the control in other developmental stages. The effects of tannic acid on GSTs specific activity were dependent on dosage and time. Low dosage and/or short time of treatment with tannic acid induced high level of GSTs specific activity in both midgut and fat body, while high dosage and/or long time of treatment either depressed GSTs activity or had no effect on it. When cotton bollworms were fed on artificial diet with tannic acid over 4 continuous generations, their GSTs specific activity in the 6th instar was all depressed in midgut, while either depressed or not different from control in fat body. After 4 generations treatment with tannic acid, the larvae of cotton bollworms were more susceptible to deltamethrin, but had no significant difference in susceptibility to parathionmethyl.
    Effects of sublethal doses of anticholinesterase agents on toxicity of insectici des and their induction to acetylcholinesterase (AChE) activity in Helicoverpa armigera
    LIU Bo, GAO Xi-Wu*, ZHENG Bing-Zong
    2003, 46(6):  691-696. 
    Abstract ( 2718 )   PDF (368KB) ( 904 )     
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    Effects on toxicity of insecticides by sublethal doses of anticholinesterase agents (phoxim, malathion and methomyl) and their induction of AChE specific activity, the Michaelis constants(Km) were investigated in the larvae of the cotton bollworm, Helicoverpa armigera(Hübner). The results indicated that toxicity of five insecticides had significant differences at 24 hours after treatments. The AChE specific activity of cotton bollworm was moderately depressed at 24 hours after treatment with LD10 of phoxim. The timecourse study revealed that the maximum induction of AChE specific activity by malathion and methomyl was observed at 3 h and 12 h after treatment, resulting in a 1.45fold and 1.92fold increase of AChE activity, respectively. The sublethal dose of phoxim had no effect on the affinity of AChE toward acetylthiocholine in 48 hours after treatment, but AChE affinities were significantly reduced after treatment with LD10 of malathion and methomyl. The density gradient centrifugation showed that the distribution of AChE activity in the 5% gradient layer was higher than the control at 24 hours after treatment with sublethal doses of anticholinesterase agents, but lower in the 20% gradient layer. It was inferred that treatment of sublethal doses may cause the changes in molecular forms and the distribution of different molecular forms of AChE.
    Effects of insectresistant transgenic rice lines MSA and MSB on nontarget pe sts Nilaparvata lugens and Sogatella fucifera
    FU Qiang, WANG Feng, LI Dong-Hu, YAO Qing, LAI Feng-Xiang, ZHANG Zhi-Tao
    2003, 46(6):  697-704. 
    Abstract ( 3439 )   PDF (442KB) ( 1164 )     
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    The effects of two insectresistant transgenic rice lines MSA and MSB, containing both SCK and cy1Ac genes, on nontarget pests Nilaparvata lugens and Sogatella fucifera were investigated. Compared with the parent line Minghui 86, MSA showed no significant effect on the biological parameter of the nontarget insect pests, including nymphal duration, fresh weight of newly emerged adult, emergence rate, brachypterous rate, adult fecundity, rate of eggs fertilized, number of offsprings per female and their development. MSB rice did not markedly influence most of the biological indices of the two species of planthoppers although the fresh weight and brachypterous rate of emerged females of S. fucifera, and the weight of emerged males of N. lugens decreased significantly. It was observed that S. fucifera obviously preferred MSA and MSB to Minghui 86 in host selection behavior in short distance (about 8 cm) while N. lugens did not. However, the density of rice planthoppers (mainly S. fucifera) in fields was generally lower on MSB than on Minghui 86, although the difference was not significant. These results suggested that the ecological risk of transgenic rice MSB causing the outbreak of rice planthoppers was small.
    Effects of transgenic Bt cotton and transgenic Bt+CpTI cotton on populat ion dynamics of main cotton pests and their natural enemies
    SUN Chang-Gui, ZHANG Qing-Wen*, XU Jing, WANG Yin-Xia, LIU Jun-Li
    2003, 46(6):  705-712. 
    Abstract ( 3023 )   PDF (469KB) ( 1054 )     
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    Systematic studies were carried out on effects of univalent transgenic cotton(GK321) containing the gene CryIAc and bivalent transgenic cotton (SGK321) carrying the genes CryIAc+CpTI on population dynamics of the main pests and their enemies in experimental fields of Chinese Academy of Agricultural Sciences (Xibeiwang, Beijing) from April to October in 2002 This experiment included three treatments. The first was a univalent transgenic cotton plot (UTCP), the second a bivalent transgenic cotton plot (BTCP), and the third a routine cotton plot (RCP). The results indicated that both univalent and bivalent transgenic cottons were excellently resistant to the cotton bollworm, Helicoverpa armigera. There was no significant difference in resistance between bivalent and univalent transgenic cottons in the second generation of cotton bollworm; but the resistance of bivalent cotton was significantly higher than that of univalent cotton in the third generation: number of larvae in bivalent cotton plot decreased by 36.6% compared with univalent cotton plot. The populations of nontarget pests in transgenic plots were significantly higher than those in normal cotton plot; with regard to individual pest species, number in bivalent and univalent transgenic plots was different. Compared with univalent cotton plot, Aphis gossypii Glover, Empoaca biguttula Shiraki and Bemisia tabaci Gennadius in bivalent transgenic cotton plot decreased in individual number respectively by 33.0% (P<0.01), 50.6% (P<0.01) and 22.7% (P>005), but Thrips tabaci Lindeman and Lygus lucorum MeyerDür increased respectively by 208.9% (P<0.01) and 18.4% (P>0.05). The population sizes of majority of natural enemies (including predatory and parasitic enemies) investigated were significantly lower in transgenic otton plots than in normal cotton plot. Compared with univalent cotton plot, Propylaea japonica(Thunberg), Lysiphlebia japonicus Ashmead and Allothrombium ovatum in bivalent transgenic cotton plot decreased in individual number significantly by 30.4%, 42.8% and 46.8% respectively. Eggs of Chrysopa sinica Tjeder and Araneida decreased respectively by 20.0% and 27.4% with no significance; Chrysopa sinica Tjeder and Orius minutus Linnaeus increased respectively by 27.0% significantly and 8.9% with no significance.
    Use of MODIS data to detect the Oriental migratory locust plague: A case study I n Nandagang, Hebei Province
    JI Rong, ZHANG Xia, XIE Bao-Yu, LI Zhe, LIU Tuan-Jie, LIU Chuang, LI Dian-Mo
    2003, 46(6):  713-719. 
    Abstract ( 3460 )   PDF (1219KB) ( 1189 )     
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    Outbreaks of the Oriental migratory locust, Locusta migratoria manilensis(Meyen) have once again become a serious problem in the last two decades of the 20th century in China. One of the coastal breeding areas of the locust, Nandagang reservoir of Hebei Province was chosen as study area in this paper. Against the background of the locust outbreak (summer locust) of this area in 2002, spectral reflectance curves of reeds for different damaged degrees (heavy, moderate or no damage) were measured and determined. The results showed that healthy reeds manifested the “peakandvalley” configuration as that of other healthy green vegetation. But for damaged reeds the red reflectance increased, and the heavier the damage, the higher the red reflectance values, whereas the reflectance in the near infrared bands decreased dramatically with the damage scalating. Additionally, the locustdamaged areas and degrees were determined using MODIS data. Comparisons of NDVI changes between pre and postdamage showed that the increase for the same site in NDVI relative to the predamage situation corresponded to the undamaged areas whereas the decrease in NDVI corresponded to the damaged areas. Coupled with the ground truth data, critical values of NDVI for heavy and moderate damage were determined as 0.2156 and 0.2389 respectively. Namely, areas with NDVI less than 0.2156 were identified as with heavy damage; while areas with NDVI less than 0.2389 as with moderate damage. By calculating the numbers of pixels, areas discriminated from MODIS images as with heavy and moderate damage were 168.74 hm2 and 337.48 hm2 respectively, with 72.97% and 68.35% accuracy respectively evaluated by the ground truth data. The total damaged areas identified from MODIS data amounted to 82.67% of actual occurrence areas. These findings contributed to the scientific foundation for quickly monitoring the dynamics of locust populations in real time and at large scale and efficiently controlling locust plague.
    Influences of pine needles from different pine forests on the growth and develop ment of the massonpine caterpillar, Dendrolimus punctatus Walker
    LIU Xing-Ping, WANG Guo-Hong, LIU Xiang-Hui, HAN Rui-Dong, GE Feng
    2003, 46(6):  720-726. 
    Abstract ( 3333 )   PDF (415KB) ( 1212 )     
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    The growth and development of the massonpine caterpillar,Dendrolimus punctatus Walker was measured after being fed on pine needles from massonpine and slash pine in different pine forests. Shorter developmental period, higher mortality, greater pupation rate, emergence and fecundity were observed in pine caterpillars fed on massonpine needles compared to those fed on slash pine needles. Also, the food consumption and utilization of pine caterpillars fed on massonpine needles were higher than those fed on slash pine needles. Massonpine caterpillars had greater potential to improve their growth and development and enhance their fecundity and feeding efficiency when fed on massonpine needles or slash pine needles from pure pine forest compared to those fed on needles from mixed pine forest. Moreover, the management implications for pine caterpillars of mixed pine forest are discussed.
    A quantitative study on the food chain of late-season rice-Nilaparvata lugens Stål-Pirata subpiraticus (Bosenberg et Strand)
    HE Yi-Yuan, WEN Dou-Dou, HU Liang-Xiong, WANG Hong-Quan
    2003, 46(6):  727-731. 
    Abstract ( 2854 )   PDF (277KB) ( 1036 )     
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    Using fluorescent element Eu+3 tracing method, the food chain of late-season rice-Nilaparvata lugens Stål-Pirata subpiraticus (Bosenberg et Strand) was studied quantitatively. Three concentrations of Eu2O3, 20 mg/L, 50 mg/L and 100 mg/L, with no obvious negative effect on growth of rice plant, were applied in substrate of potted rice, respectively. During rice booting, tasseling, milking and maturing stages, the content of u+3 in rice, N. lugens and P. subpiraticus markedly increased with the rise of concentrations of Eu2O3 applied. Ingestion of rice by N. lugens during the tasseling stage was the highest (17.5910 g/g biomass day), while the lowest (8.7070 g/g biomass day) occurred during the maturing stage. Between them, ingestion of rice by the planthopper was higher during the booting stage (17.4510 g/g biomass day) than during the milking stage (13.8290 g/g biomass day). Predation of N. lugens by P. subpiraticus was almost the same, about 3.6380 g/g biomass per day during the milking stage, higher than during the booting stage (3.0830 g/g biomass day) and the tasseling stage (3.0770 g/g biomass day) while the smallest predation (28000 g/g biomass day) occurred during the maturing stage. Based on the investigation in rice fields, the number of N. lugens consumed by P. subpiraticus during these four growth stages of the rice plant was estimated to be 11, 11, 13 and 10 respectively.
    Observations on the flight behavior of the oriental armyworm, Mythimna separat a (Walker) in airflow
    YIN Jiao, FENG Hong-Qiang, CHENG Deng-Fa, CAO Ya-Zhong*
    2003, 46(6):  732-738. 
    Abstract ( 3208 )   PDF (968KB) ( 1057 )     
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    Flight behavior of the oriental armyworm Mythimna separata(Walker) moth in airflow was studied systematically using wind tunnel and scanning entomological radar. The results showed that the moths responded obviously to wind in the cylindrical wind tunnel, and they took off and flew against airflow in flight. When the wind speed was 3.0~5.5 m/s, up to 92%~94% moths tested could fly through the 2meter wind tunnel; while, only 71.9% tested moths flew helically through the cylindrical wind tunnel against airflow when the wind speed reached to or over 6.0 m/s. In the annular wind tunnel, their maximum flight speed was 7.2 m/s; more than 90% of the tested moths flew with certain angle against airflow when the wind speed was or over 4.0 m/s. Radar observations indicated that the stratification occurred in the course of the Oriental armyworm migration. The moths headed southwest in autumn migration. The flight displacement of the moths was related to wind direction and speed.
    Repellent effects of herbivoreinduced rice volatiles on the brown planth opper,Nilaparvata lugens Stl
    ZHOU Qiang,XU Tao,ZHANG Gu-Ren,GU De-Xiang, ZHANG Wen-Qing*
    2003, 46(6):  739-744. 
    Abstract ( 3132 )   PDF (328KB) ( 1306 )     
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    Rice plants response to insect herbivory by synthesizing and releasing complex blends of volatiles, which provide important host location cues for herbivores and its natural enemies. The behavioral responses of adult brown planthopper, Nilaparvata lugens Stal to eleven herbivoreinduced rice volatile compounds were studied with a Ytube olfactometer. The results showed that four compounds, (E)-2-hexenal, (E)-2-hexen-1-ol,-2-heptanol and methyl salicylate,had significantly repellent effects on the adult brown planthopper under the tested concentrations(2-μL compounds were dissolved in 100 μL acetone respectively),however,seven other compounds,(E)-2-hexen-1-ol,-2-heptanone, limonene, ocimene, linalool,-β-caryophyllene and (E)nerolidol, had no significant effects on the selection behavior of the adult brown planthopper under the same concentration. Further experiments showed that the volatile compounds, (E)-2-hexenal and linalool,had no significant effects on the selection behavior of the adult brown planthopper at lower concentrations [(E)-2-hexenal (0.5 μL, 1 μL) and linalool (0.5 μL, 1 μL, 5 μL) were dissolved in 100 μL acetone respectively]. However,these volatile compounds had markedly repellent effects on the selection behavior of the adult brown planthopper at higher concentrations [(E)-2-hexenal(5 μL, 10 μL) and linalool(10 μL) were dissolved in 100 μL acetone respectively].
    Effects of extraction from nymphs, exuviae and adults of Bemisia tabaci B biotype on the behavior of Encarsia bimaculata Heraty et Polaszek (Hymenoptera: Aphelinidae)
    Nasser S. MANDOUR, REN Shun-Xiang, QIU Bao-Li,Sahar FAZAL
    2003, 46(6):  745-748. 
    Abstract ( 2591 )   PDF (219KB) ( 899 )     
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    The response of female Encarsia bimaculata Heraty et Polaszek to its host, Bemisia tabaci (Gennadius) nymph, exuviae or adult extractions was bioassayed in a petri dish arena. The tested materials were extracted by hexane, ethanol and water. The data show that females spent much longer times searching in treated patches than controls. The parasitoids intensified their search in the treated patches and exhibited both orthokinetic and klinotaxic responses. The highest mean of the retention time in the treated patches was in those treated with material extracted from nymphs with water (111.23 seconds), otherwise parasitoids spent equal time in treated patches irrespective of the concentrations of the tested materials. Such kairomones might enhance female searching efficiency and guide them to hosts.
    Learning in host foraging by the parasitoid Diadegma semiclausum (Hymenopter a:Ichneumonidae)
    LI Xin, LIU Shu-Sheng*
    2003, 46(6):  749-754. 
    Abstract ( 2634 )   PDF (365KB) ( 1097 )     
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    Learning of host and hostplant recognition in the larval parasitoid Diadegma semiclausum Hellen (Hym., Ichneumonidae) was studied. The results show that the hostplants fed on by host larvae of parasitoids during their immature stages did not affect hostplant preference of the ensuing female adults, but brief experiences by female parasitoids at early adult stages significantly affected their subsequent host preferences. Female parasitoids showed significant preferences for plant volatiles they had previously experienced. However, such preferences acquired through learning could be modified by new experiences. Female parasitoids could learn not only the volatile chemicals emitted by hostinfested plants, but also the infochemicals emitted by host larvae.
    The genus Cinygmina(Ephemeroptera:Heptageniidae) in China, with a description of a new species
    ZHOU Chang-Fa, ZHENG Le-Yi
    2003, 46(6):  755-760. 
    Abstract ( 3803 )   PDF (293KB) ( 969 )     
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    Chinese members of the genus Cinygmina are reviewed. Four known species (C. hunanensis, C. obliquistrita, C. rubromaculata, C. yixingensis) and one new species (C. furcata sp. Nov.) are compared, described and illustrated. One new synonym, C. ubromaculata (=C. hainanensis) is established.
    Analysis of relationships among species in the genus Loxoblemmus (Orthoptera : Grylloidea, Gryllidae) using random amplified polymorphic DNA(RAPD)
    LI Kai, ZHENG Zhe-Min, CHEN Li-Qiao
    2003, 46(6):  761-765. 
    Abstract ( 2593 )   PDF (358KB) ( 916 )     
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    The technique of random amplified polymorphic DNA (RAPD) was used to study the relationships of 9 species in the genus Loxoblemmus. A total of 27 samples were used in this study: 3 samples for each species. Among 54 arbitrary primers (10 bp) under predetermined optimal reaction conditions, 9 primers were informative and yielded a total of 193 clear and reproducible bands. Dendrograms were constructed based on genetic distance by the UPGMA method. Individuals of the same species clustered together. The relationships indicated by cluster analysis was mostly the same as those based on comparative morphology.
    Advances in insect virus synergists
    GUO Hui-Fang, FANG Ji-Chao, HAN Zhao-Jun
    2003, 46(6):  766-772. 
    Abstract ( 2867 )   PDF (481KB) ( 1134 )     
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    This paper summarized the recent advances in insect virus synergists, including the synergistic characteristics and mechanism of viral enhancin, a biological synergist from insect viruses, and the optical brightener, a chemical synergist. The paper also gave a framework of the molecular biology of enhancin. Viral enhancin was found in nuclear polyhedrosis virus, granulosis virus, cytoplasmic polyhedrosis virus and entomopoxvirus, and it was metalloproteases. Several enhancin genes have been cloned, based on that, some enhancin recombinant virus and plant has been constructed. Optical brightener with enhancing activity were stilbenes. It has been confirmed that the destruction of peritrophic membrane contributed to the enhancement of viral infectivity by synergists. Other mechanism related to the enhancement needs further study. Finally the use of insect virus synergists was discussed.
    Insect chromosome research in China: Status and perspectives
    ZHANG Li-Sheng, ZHANG Qing-Wen*, CAI Qing-Nian, XU Jing, ZHOU Ming-Zang
    2003, 46(6):  773-782. 
    Abstract ( 3861 )   PDF (741KB) ( 1152 )     
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    This paper gives a review of the present status and perspectives of insect chromosome research in China, including: insect groups studied, results of karyotype analysis, technique and methods adopted, chromosome mitotic and meiotic division, and chromosome modality aberrance, structure aberrance and quantity aberrance. Chinese scholars had begun the study on insect chromosome since 1930s. The karyotypes of 481 species insects belong to 10 orders have been studied by now in China, mainly concentrated on such groups as locusts, grasshoppers, stinkbugs, aphids, mosquitoes, flies and silkworms. Researches in chromosome behavior included: the mitosis of silkworms and fruit flies; the meiosis and the sexual determination mechanism of Blattaria, locusts, grasshoppers, stinkbugs and silkworms; and the synaptonemal complexes of Blattaria and silkworms. Research on chromosome structure variation focused on: salivary gland chromosomes of fruit flies and mosquitoes; B chromosomes of the fruit flies; the chromosome deficiency, repetition, inversion and translocation of silkworms and mosquitoes; and the chromosome quantity variation of the silkworms and moths. Moreover, these results were mainly used to explore insect systematics and evolution, regulation of insect heredity and variation, and so on. Through comparing domestic and international research results, necessities in this research field in China were proposed, and a perspective was given.
    Genetic structure of geographic populations of Sitodiplosis mosellana (Gehin ) (Diptera:Cecidomyiidae)in China
    HE Chun-Gui, YUAN Feng,ZHANG Ya-Lin
    2003, 46(6):  783-787. 
    Abstract ( 2596 )   PDF (241KB) ( 966 )     
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    Ten geographic populations of the orange wheat blossom midge, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae) from all wheat grown area in China were investigated by RAPDPCR to determine their genetic structure. Samples of 10 adults were examined for each population. Five selected primers, S18 CCACAGCAGT, S32 TCGGCGATAG, S83 GAGCCCTCCA, S169 TGGAGAGCAG and S250 ACCTCGGCAC, produced a total of 326 RAPD markers. No specific band was observed for every population. The distance analysis shows that similarity within a geographic population is higher than that among different populations; the similarity index (Sxy) among the populations is inversely proportional to the direct distance among them. Cluster analysis by UPGMA shows that the 10 geographic populations could be gathered into two big groups: spring wheat region group and winter wheat region group.
    Resistance selection by abamectin, pyridaben and fenpropathrin and activity change of detoxicant enzymes in Tetranychus urticae
    ZHAO Wei-Dong, WANG Kai-Yun*, JIANG Xing-Yin, YI Mei-Qin
    2003, 46(6):  788-792. 
    Abstract ( 3624 )   PDF (315KB) ( 1172 )     
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    The selection for resistance by abamectin, pyridaben and fenpropathrin to Tetranychuc urticae were carried out in laboratory, as well as activity change of detoxicant enzymes. The susceptible population of T. urticae was separately treated with abamectin, pyridaben and fenpropathrin imitating field chemicals selection pressure in order to breed its resistance. The results showed that the resistance of T.urticae had reached 6.72fold to abamectin, 19.9fold to fenpropathrin and 12.1fold to pyridaben after 12 generations treatment. The resistance mechanism was evaluated by activity measurement of enzymic inhibitors and detoxicant enzymes. It was concluded that the rise of resistance to abamectin was mainly associated with increased activities of mixedfunction oxidases and glutathione S-transferase; the resistance to pyridaben was attributed to increased activIties of carboxylesterase and mixedfunction oxidases; the main cause of resistance to fenpropathrin was the increased activities of carboxylesterase and glutathione S-transferase.
    Comparison of activities of detoxic enzymes in the imidaclopridresistant and s usceptible strains of the cotton aphid, Aphis gossypii
    PAN Wen-Liang,DANG Zhi-Hong,GAO Zhan-Lin
    2003, 46(6):  793-796. 
    Abstract ( 2752 )   PDF (226KB) ( 1275 )     
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    The activities of two metabolic enzymes in the imidaclopridresistant (about 7fold) and susceptible strains of the cotton aphid, Aphis gossypii were compared by biochemical methods. Piperonyl butoxide (Pb) had no synergism to imidacloprid in both of the strains. Activities of carboxylesterases (CarE) and gluathione Stransferases (GSTs) in the resistant strain were significantly higher than that in the susceptible one. The Km of CarE in the resistant strain were also significantly higher than in the susceptible strain, which means that the resistant strain had higher affinity of CarE with the substrate. The results showed that the enhancement of activities of CarE and GSTs would be the main metabolic mechanism in the resistance of A. gossypii to imidacloprid.
    The efficacy of two synergistic mixtures isoprocarb·abamectin and profenophos· abamectin to Spodoptera exigua Hübner
    ZENG Yi-Liang, WANG Wen-Lan, KANG Le, WANG Da-Sheng, WANG Cheng-Ju, CHENG Shang-Wu, WANG Bao-Ying, WANG Tong-Shun, QI Jia-Yan, QIN Xiao-Wei
    2003, 46(6):  797-800. 
    Abstract ( 2923 )   PDF (245KB) ( 1065 )     
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    Through field trials, the efficacy of two synergistic mixtures, isoprocarb+abamectin 24% EC and profenophos+abamectin 35% EC, to Spodoptera exigua Hübner larvae were assayed in Qingzhou, Shandong Province in 2002 The effects of isoprocarb+abamectin 24% EC were significantly better than that of isoprocarb 25% EC and abamectin 1.8% EC. In the application rate of 50 g/667m2 the correct mortality isoprocarb+abamectin 24% EC after 3, 7, 10 days were 82.38%, 87.49% and 88.90% respectively; in 37.5 g/667m2 , the corresponded control effects were 78.21%, 8397% and 85.24% respectively. The correct mortality of profenophos·abamectin 35% EC in the application rate of 50 g/667m2 after 3, 7, 10 days were 86.15%, 91.37% and 91.32% respectively; in 37.5 g/667m2, the corresponded control effects were 80.73%, 87.40% and 88.39% respectively. This synergistic mixture possessed a quick action, good residual performance and relatively low cost guarantee for the good control effect in the field.