Since 1949, encouraged by control of malaria and other mosquito-borne diseases and the National Patriotic Health Movement, the mosquitoes studies in China have been greatly strengthened. Important progress has been made in the studies of biosystematics, bionomics, vector relationships and integrated management of mosquitoes.

Spatial ecology has recently attracted more and more interest from a wide range of ecologists. The theory and methodology of metapopulation ecology is an important part in this field, with which a dramatic increase of publications has dealed in the recent two to three years. Several important monographs were also published. The case studies on the Glanville fritillary butterfly (Melitaea cinxia L.) by Hanski et al., has been reviewed and combined with our own experience. By understanding the approaches being utilized, the type of data gathered, the ways to analyze the data, and the features of the results obtained, this paper seeks to analyze the actual meanings, features and the applied prospects of metapopulation theory and methodology.

Three susceptible mosquito populations from China were analyzed for esterase haplotype polymorphism by starch gel electrophoresis and RFLP analysis. At the protein level, 2 and 3 alleles were found for esterase α and β respectively in a Culex tritaeniorhynchus population (n=54), at the DNA level, with the use of one restriction enzyme (EcoRI), only 239% individuals were detected sharing a 1.3 kb single copy band which is homologous with the 1.3 kb cDNA fragment of esterase β1¹ gene. In a Anopheles sinensis population (n=50) with nonspecific esterase of low activity, 1 allele was detected for esterase α and esterase β, at DNA level, no band was found homologous to β1¹ gene. In a Culex pipiens strain of Beijing susceptible population, 5 alleles were found separately for esterase α and β at protein level, 5 alleles at the esterase β locus were detected in a sample of 15 mosquitoes from one population, with the use of only one restriction enzyme. A unique amplification event prior to extensive migration of esterase β haplotype seems the most likely hypothesis to explain the molecular data from Beijing susceptible population. This hypothesis is based on: ① the existence of much neutral polymorphism around the esterase β structural gene in susceptible mosquitoes, and ② the presence of the same amplified haplotype in populations from geographical areas far apart. The first point is supported by this study on population from Beijing. The polymorphism found around the esterase gene is probably neutral to OP insecticides, so that two distinct amplification, even of the same esterase geneallele, will probably generate two distinct amplified haplotypes. Once a haplotype has been amplified and spread in treated populations, some copies may accumulate mutations. This may generate some polymorphism in linkage disequilibrium with the other copies, as described for the β1¹ amplification. If such polymorphism is sufficiently large, it will probably allow us to reconstruct the various historical events for each of the four amplified esterases.

Culex pipiens quinquefasciatus sampled in Guangzhou in China, has larval resistance to organophosphate insecticides. The results of starch gel electrophoresis and Southern hybridization indicate that there are seven highly active esterases:esterase β11，α2/β2，α6/β6 and α8/β8 in this population. A new esterase haplotype(esterase α8/β8) was found in the populations. The results of the migration rate and RFLP polymorphism of these highly active esterases indicate the esterase α8/β8 is different from the others. In the same way,Culex pipiens quinquefasciatus populations sampled from Wuhan and Shashi in China, were analyzed. Also a new pair of esterase α8/β8 are involved in Wuhan and Shashi populations.

Biological characteristics and population parameters of the high effective cypermethrinresistant (Rc) and trichlorphon-resistant (Rt) Aedes albopictus were significantly different compared with that of the susceptible strain (S). The difference between the two resistant strains was significant too. The greater fecundity, shorter time of life cycle, and the higher rate of female were detected in Rc strain than in Rt one. The latter had obvious defect in fitness. Hatching rate of both Rc and Rt strains were lower than that of the S strain. The imaginal mortality was Rt＞Rc＞S. The results show that the high effective cypermethrin could stimulate oviposition and enhance population growth of the mosquito.

In this paper the microplate assay was used to determine AChE inhibition by different concentrations of organophosphate and carbamate insecticides. The results showed that there were no inhibition of organophosphate insecticides, such as methyl parathion, monocrotophos, omethoate and acephate to the AChE of cotton aphid. By measuring the AChE activity of individual cotton aphids on cascara and on cotton seedling in Beijing and Gaomi, Shandong Province, along with the inhibitory frequency of methomyl to it, it was found that the distributive frequency among individual AChE activities was similar among the three populations of cotton aphid tested. The individuals with inhibitory rate of methomyl to individual AChE below 30% in the three different populations were amounted to 2.4%,16%,29%,respectively.The individuals with inhibitory rate over 70%, accounted for 72%, 33% and 1% of the three populations respectively. The difference among these three populations was noticeable, and this result was in accord with the outcome of biological measurement.Consequently the method of microplate titer assay would be a better forecast skill for determinating insensitivity of AChE to carbamate insecticides in cotton aphid. It might be helpful for releasing pest resistance.

The resistance selection of diamondback moth (DBM), Plutella xylostella (L.), to avermectins (AVMs) and its effect on activities of detoxification enzymes in AVMsselected DBM were investigated during 1996～1999. After 27 generations of continuous selection pressure, resistance to AVMs was over 812-folds in this strain compared with the unselected parents. Resistance selection by AVMs has no effect on activity of acetylcholinesterase (AChE). The activities of carboxylesterase (CarE) and glutathione S-transferases (GST) in DBM larvae of F₂₇ generation increased 1.5 and 2.2-folds respectively, compared with the unselected parents (F₀). Piperonyl butoxide (Pb) can moderately increase the toxicity of AVMs to the selected strain for about 6-folds. It suggests that the resistant mechanisms of DBM to AVMs were probably associated with microsomal mixed function oxidases (MFO), GST and CarE.

By applying bioassays and biochemical analyses, the reactions to endosulfan and deltamethrin of two cotton bollworm Helicoverpa armigera (Hübner) populations, the susceptible one (collected from Xinjiang) and resistant one (by indoor selection using endosulfan and deltamethrin ),and the activity dynamics of their α-naphthylacetate esterase and acetylcholinesterase (AChE) were tested. The results showed that the resistance ratios to endosulfan and deltamethrin were 13 and 66 folds in Xinjiang cotton bollworm after selection. ΑNaphthylacetate esterase and aceylcholinesterase activities of the resistant populations were higher than that of the susceptible. Pretreated with corresponding insecticides the activity of α-naphthylacetate esterase was inhibited. The affinity of α-naphthylacetate esterase to the substrate was higher in the 2 resistant populations than the susceptible, while the maximum velocity (V_max) was lower. But the affinity of AChE to the substrate was lower and V_max was higher. It was found on the PAGE profiles that the 2 resistant populations possessed a special band and the immigration rate of this band was similar. In the resistance and susceptible populations the activity of this enzyme band can be inhibited by the inhibitor methyl paraoxon of aceylcholinesterase. These results suggested that α-naphthylacetate esterase had involved in hydrolysis and sequestration and AChE played an important role in the resistance mechanism of cotton bollworm to the 2 insecticides.

The effects of various adjuvants (mineral oil, higher aliphatic acid and nonionic surfactant) and two application methods (topical and immersion) on the penetration of beta-cypermethrin across the armyworm (Mythimna separata Walker) epidermis were studied. The results showed that the penetration was directly correlated with the concentration of adjuvants and with the time course after application, within the definite range of adjuvant concentration. A coordination effect of two types of adjuvant on the penetration was found.

Laboratory screenings were conducted for obtaining resistant population of cotton bollworm (CBW) Helicoverpa armigera (Hübner) to Bt transgenic cotton. The mode of inheritance of resistance in this population was also studied. The results showed that after selection for 16 generations, the WLC₅₀ (mean weight loss concentration) of CBW to Bt transgenic cotton was 43.3 times as many as that of the 1st generation. Owing to that the weights of the 7-day old larvae and emergence rate of adults, when fed on diets containing Bt transgenic cotton, changed significantly, these two characters were regarded as the resistance standards for screening in this study. The degrees of dominance of cross and reciprocal-cross between the resistant and susceptible populations were less than 0 according to Stone's formula. The sex ratios of the descendants of the cross and backcross groups were 1∶1 approximately. The χ² values were low as if the resistance of CBW to Bt transgenic cotton was controlled by a single gene. It is suggested that the inheritance of resistance to Bt transgenic cotton in CBW is controlled by single autosomal incomplete recessive allele.

Thirteen allozymes,α-glycerophosphate dehydrogenase (α-GPDH), acid phosphatase (ACPH), alkaline phosphatase (ALP), aldehyde oxidase (AO), esterase (EST), glutamate oxaloacetate transaminase (GOT), hexokinase (HEX), leucine aminopeptidase (LAP), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), malate enzyme (ME), phosphoglucomutase (PGM), xanthine dehydrogenase (XDH), were analysed by polyacrylamide gradient gel electrophoresis with double stain method. The genetic variations of 9 allozymes within and among 5 geographic populations were investigated. Among the 13 loci examined, 6 loci were polymorphic and 7 loci were monomorphic. The percentage of polymorphic loci was 46.15%. As calculated with the results of AO, GOT, LAP, LDH, ME and XDH, the average heterozygosity of Helicoverpa armigera was 0.1160.Among Nanjing, Chengdu, Wuxue , Hengyang and Hami populations, their mean genetic distance was 0.0008～0.0293 and mean genetic similarity was 0.9707～0.992. It means that there exits high genetic diversity in each population, but the genetic differentiation among these populations is very limited. There was no barrier of gene flow among these investigated populations. The migration could hamper more genetic differentiation among different geographic populations.

The effects of host eggs on Trichogramma dendrolimi and T. chilonis were investigated based on comparisons of the activities of carboxylesterase (CarE) and acetylcholinesterase (AChE) and their affinities toward substrates and sensitivities to insecticides. The activities of CarE in T. dendrolimi from Guangdong and Jilin Provinces reared on Antheraea pernyi eggs were lower than those of the same population reared on Corcyra cephalonica eggs, but the activity of CarE in T. chilonis from Hubei Province reared on A. pernyi eggs was higher than that reared on C. cephalonica eggs. The affinity of CarE to α-naphthyl acetate (α-NA) was higher in T. dendrolimi (Guangdong population) reared on A. pernyi eggs than those reared on C. cephalonica eggs. The affinity of AChE in the three Trichogramma populations reared on A. pernyi eggs was lower than that reared on C. cephalonica eggs. Comparing with the Trichogramma population reared on C. cephalonica eggs, the CarE of population reared on A. pernyi eggs was sensitive to SV1, and the sensitivity to paraoxon varied with the populations. The sensitivity of T. dendrolimi (Jilin population) AChE to DDVP and esterine using A. pernyi eggs as hosts was not significantly different from using C. cephalonica eggs as hosts, While, the AChE in T. dendrolimi (Guangdong population) and T. chilonis (Hubei population) reared on C. cephalonica eggs was more sensitive to DDVP and eserine than in those reared on A. pernyi eggs.

A lipophorin was isolated and purified from whole body of third instar mature larvae of pine needle gall midge,Thecodiplosis japonensis(Uchida et Inouye) by KBr density gradient ultracentrifugation and Sepharose CL-4B gel permeation. It is the second lipophorin that have been purified from whole body. The native molecular weight was 638 kD by gel permeation chromatography. It was composed of two subunits, named as apoLp-Ⅰ and apoLp-Ⅱ, with molecular weight of 240 kD and 52 kD respectively. The holoprotein contained 52.8% protein and 47.2% lipid by weight. Sudan Black B and Periodic acid／Schiffs' reagent staining showed positive results, indicating a kind of glycolipoprotein. Its density was 11.1 g／mL, showing a kind of high density lipoprotein. The presence of high content of lipophorin in wholebody of third instar, suggesting a potential role in lipid transport and／or cryoprotection during the overwintering periods.

A comparative study on the toxicity and deterrence among crystal, spore and thuringiensin A of Bacillus thuringiensis against Helicoverpa armigera(Hübner) was carried out. The parasporal crystals of Btk HD-1 were highly toxic and feeding deterrent to H. armigera larvae. The spores of Btk HD-1 showed some insecticidal activity and highly feeding deterrence. The spores of a HD-1 mutant without crystal, Cry-, had no toxicity and feeding deterrence. The thuringiensin A greatly inhibited larval development, but had no feeding deterrence. In the no choice test, larval feeding was arrested by HD-1 crystals, but HD-1 spores, mutant Cry- spores and thuringiensin A had no effect on larval feeding during the 45 min observation. When the crystal-spore mixture is combined with thuringiensin A, larval mortality was greatly increased.

Insecticidal engineered bacteria of cotton are recombinant bacteria by introducing the cryIA© gene from Bacillus thuringiensis subsp. Kurstaki into the chromosome of Bacillus cereus(Bc9102) which is a dominant endophytic bacterium in cotton. In vitro bioassays with cotton bollworm (Helicoverpa armigera) was conducted and the results showed: at each concentration level, engineered strains HE-1,HE-2,ME14-2,ME14-3 and MK14-1 had a higher insecticidal activity than Bt strain HD-73, causing 96.7%,83.3%,93.3%,83.3%,80.0% mortality respectively at the highest concentration while Bt HD-73 had 80% mortality. The concentration mortalitey curves of these strains showed a linear correlation. In planta bioassays, the results showed that insecticidal activity of cotton injected or sprayed with engineered bacteria was obviously better than that of cotton seedtreated with engineered bacteria. For example, engineered strain HE-1 had larval mortality respectively 90.0%、76.0% and 23.3% after injection,spraying and seedtreatment 4 weeks. At the same time, engineered bacteria restrained the development of cotton bollworms.

Xenorhabdus spp. And Photorhabdus spp.are entomopathogenic bacteria symbiotically associated with insect pathogenic nematodes of the families Steinernematidae and Heterorhabditidae. Six strains were isolated from their nematode symbiots.Crude insecticidal material was precipitated with ammonium sulfate at 85% saturation from cell-free culture.By the means of bioassay, Xenorhabdus bovienii strain A54 was found highly toxic to insects. Injection of the toxin killed 93.3% of Galleria mellonella larvae within 96 h. Feeding artificial diet with the toxin, the mortalities of larvae of Ostrinia furnacalis and Helicoverpa armigera were 100% and 90% within 120 h respectively. Isolated by DEAE-52 column,a penetrating peak and three NaCl eluting peaks were obtained from the crude extract.Materials from the penetrating peak had oral insecticidal activity against H.armigera,but no toxicity when injected into the hemolymph of G.mellonella. Materials from three NaCl eluting peaks had high toxicity when injected, but no toxicity when given orally. Meanwhile, feeding artificial diet with the toxin, the mortalities of 2-instar and 3-instar larvae of H.armigera were 65% and 30% within 96 h respectively.

The pathogen of the Apis cerana cerana F. larvae naturally infected with European Foulbrood (EFB) was isolated and identified. The results indicate that the pathogen is Melissococcus pluton, a Grampositive anaerobe or microaerophile. Its cellular morphology, stained characteristics, infecfivity, serology and G+C content in DNA are similar to that in A.mellifera L.,suggesting the EFB pathogen of A.cerana cerana F.to be Melissococcus pluton as in A.mellifera.The physiological and biochemical characteristics of EFB pathogen in Apis cerana cerana F.are approximately in accordance with an earlier study on A.mellifera L.by M.F.Allen.

In this study the authors using Nosema locustae as a parasite on Locusta migratoria manilensis, measured the content of glyceride and lipase activity in haemolymph and the total fat of the locust infested. The results manifest that N. locustae can cause the content of glyceride in haemolymph and the total fat of L. migratoria manilensis decline rapidly and the lipase activity in haemolymph rise rapidly. A new identifying method of grade of disease according to the physiological guideline is suggested.

Behavioral changes of the cotton bollworm moth, Helicoverpa armigera (Hübner), caused by high concentration of sex pheromone were observed. The results showed that the female moths behaved more actively in response to the sex pheromone concentration tested. Their average staying time and copulation duration were shortened and more time was spent on calling. On the contrary, the male moths significantly cut down their calling time and spent more time on staying. There were no significant changes in feeding and oviposition behaviors. When their mating rates were taken into account, there was no significant difference between the treatment and the control. However, mating peak and initial copulation time of the females in the treated group were greatly delayed. It is suggested that copulation quality, rather than mating percentage, was influenced in this insect species under condition of high sex pheromone concentration.

Microplitis mediator is one of the key parasitoid wasps which attack cotton bollworm Helicoverpa amigera. The odors released from host plants serve vital roles in its host finding behavior. Electroantennograms were recorded from female Microplitis mediator to 17 cotton volatile compounds. The EAG differences between female and male wasps to 6 compounds were compared, and EAG doseresponse curves were also constructed for females to 4 compounds. Aliphatic compounds elicited the largest EAGs. Aromatic derivatives elicited moderate EAGs, while terpenoid elicited the lowest EAGs. No sexual difference was found in EAGs to 6 compounds. The load thresholds for hexanal, acetophone and nonanol were 25 μL, while that for bezenaldhyde was 250 μL. None of the compounds reached saturation at the stimulus load series.

(-)-(1R,4aS,7S,7aR)-nepetalactol and (+)-(4aS,7S,7aR)-nepetalactone have been identified in sex pheromones released by a number of aphid species. From 19th to 28th,Oct.,1995, in a peach orchard experiment in Daxing county using white water traps of different ratios of the two components, 96% nepetalactone isolated from Nepeta cataria L.and 67% nepetalactol reduced from nepetalactone with diisobutylaluminium hydride,significantly more male Myzus persicae (Sulzer), male Hyaloptera amygdali Blanchard and gynoparae of M. persicae were caught in pheromone traps than in the control traps. Response of gynoparae was relatively weak than males.Male M. persicae were caught in significantly larger number in trap with ratio 1∶1 than others, and male H. amygdali were caught in significantly larger numbers by nepetalactol alone than by the other combinations.

A comparative study on the antennal sensilla of various forms of Myzus persicae is undertaken. Scanning electron microscopy revealed four kinds of antennal sensilla, campaniform sensillum, trichoid sensillum, primary and secondary rhinarium. A major difference between various forms of M. persicae lies in the abundance of secondary rhinaria. Male, gynopara and alate virginopara possess secondary rhinaria, ovipara, fundatrix and apterous virginopara have none. Nevertheless, male aphids have more numbers of secondary rhinaria than gynoparae and alate virginoparae, and the sensilla are found not only on the 3rd antennal segment, but also on the 4th and 5th segments of males. The role of antennal sensilla in chemical ecology of peach aphid and the differences between various forms of peach aphid in correlation to migration, host selecting and mating behavior are discussed, sexual dimorphism in the antennae of M. persicae is also discussed.

Effects of water intake on diapause termination and pupation of overwintered larvae of Asian corn borer (ACB) were determined by providing the larvae with water on the 5th, 15th, 25th, 35th, 45th and 55th day after incubation at the alternative temperatures from 22℃ to 28 ℃(22～28℃) and 16℃ to 22℃(16～22℃), respectively. The results showed that the larvae were incapable of terminating diapause and completing prepupal development until they had drank water. The survival and pupation rates of the larvae increased with increase of larval weight because of water drinking. The highest pupation rate at 22～28℃ was recorded when the larvae drank water on the 35th day while that at 16～22℃ occurred when the larvae drank on the 55th day. The diapause development of the larvae was more rapid under 22～28℃than under 16～22℃ whenever water was offered. Therefore, it is concluded that the raining time and precipitation in spring may affect the pupation progress and rate of development of the overwintered ACB larvae in field.

Two sampling plots of the same area(22 m×22 m)with the alike stand were respectively selected within the samiliar pine stands in Jinsishan (JSS), Daigongshan (DGS), Jiulianshan (JLS) and Magushan (MGS) Forest Farms alone the south shore of Yangtse River in Anhui Province. Orthopterous insects in tree layer, shrub and herb layer, litter layer and soil layer were investigated in every month from Aug. 1998 to Jul. 1999. The results showed that: ①Catantops pinguis (Stal)was dominant in the 4 forest farms, and Locusta migratoria manilensis(Meyen), Atractomorpha sinensis I. Bolivar, Holochlora japonica Brunner-Wattenwyl and Gryllus testaceus Walker were common ; ② the number of species and of individuals,and the diversity index in DGS, JSS, MGS and JLS Forest Farms were 27, 159, 1.28 ; 26,70,1.32 ; 35,171,1.42 and 20,90,1.33, respectively; ③ all the insect species found and 80 % of individuals were in the shrub and herb layer; ④ plenty of herbs and streams in MGS Forest Farm provided good habitat for the orthopterans and the intensive spray of insecticides for many years favoured their development.It is suggested that heavy depression of their natural enemies by the application of the chemicals resulted in greater diversity and recovery stability of the orthopteran community in this forest farm than in the other ones.

This paper deals with evaluation of the mass propagation system of Aphidoletes aphidimyza using life table. It was showed that high mortalities in the stages of egg(13.5%),1st instar larvae (18.2%) and pupae (19.0%) were the main factors influencing the growth of the experimental population. Abnormal sex ratio caused by the propagation of many successive generations also resulted in reducing viability of the experimental population.These results suggest that the existing propagation system needs to be improved.

The broad mite,Polyphagotarsonemus latus(Banks),can stick to the greenhouse whitefly，Trialeurodes vaporariorum for longdistance dispersal.Cage experiment revealed that the phoresy of P.latus by whitefly is their biological characteristics,not the stress response to adverse environment.The ANOVA analysis showed:18～25℃ and 50%～75% RH were suitable for the phoresy,which coincide with their favorable living condition.High temperatures(32～39℃)speeded up sticking,but rate of phoresy decreased rapidly after 2 h.Effect of illumination on rate of phoresy was little.With mite density rising,both rate of phoresy and mite number on a whitefly increased obviously.85% of the phoretic mites clasped tarsi and tibia of the whitefly in a way of metapodosoma warping at an angle of about 45°.Examination by phase contrast microscope showed that the broad mite thrusted its stylet into the leg of the whitefly.Therefore the relationship between them still needs further research.

This paper deals with 15 species of the genus Tinocallis Matsumura from China.T. microtylodes sp. nov. is described as new. T. platani (Kaltenbach) and T. magnoliae Ghosh & Raychaudhuri are newly recorded from China. A key to the Chinese species, detailed host-plants and geographical distribution of every species and morphological features of new species are provided in this paper. All specimens including type specimen are deposited in Institute of Zoology,Chinese Academy of Sciences.

This paper deals with the endemic curviceps species-subgroup of Drosophila(Drosophila) immigrans species-group in China, including 9 known species and 2 new species, D.shi sp.nov. and D.brevipapilla sp.nov. Among them, 3 pecies(audientis,taipinsanensis and nigrodigita)are distributed in Taiwan, and all other species in Chinese continent,concentrating in southern-west China and showing distinctly geographical replacement.All the types are deposited in the College of Life Sciences,Peking University,except for 1♂ paratype of brevipapilla which is deposited in Kunming Institute of Zoology,the Chinese Academy of Sciences.

This paper reviews the history of controlling the locust, Locust migratoria manilensis,in China this century and proposes new assumptions on how to sustainably manage the insect pest. In recent years,biological control of the locust has succeeded to some extent and this strategy had developed in certain areas of our country. In order to prevent or delay development of the locust from solitary phase to gregarious one the biological agents such as Nosema locustae should be used mainly.When high density occurs the IGRs or other chemicals and N.locustae must be used together at certain proportion to reduce the population rapidly,and the N.locustae disease may be epidemic in depressed locust populations in this case.The semiochemicals of locusts should be also studied and developed as one of potential measures for controlling the insect pest.

Distribution of Oxya chinensis was investigated in rice field and the result indicated that 1～3 instar nymphs mainly gathered on weeds around the field. When they grew up to 4～6 instars, the nymphs gradually dispersed into the field. The laboratory experiments showed that the LC₅₀ of 5% Cascade^® (IGR) against the grasshoppers was about 54.27 μg/mL. The optimum dosage for field spraying was estimated at 105 mL/hm². When high density of the insect pest occurred, the integrated application of Nosema locustae and IGR was effective and more than 35.6% of the surviving grasshoppers were infected by N. locustae. This is a lowcost and sustainable measure with good prospects in practical application.

Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is one of the important international quarantine pests,and one of the main plant quarantine insects China guards against,that has been intercepted for twelve times in the port quarantine in recent years,of which the potential risk has been shown fully. China has taken a series of strict quarantine measures and prevented the entry of Mediterranean fruit fly effectively. In the meantime the quarantine policy was adjusted in order to meet the requirements of the development of reform and opening to the outside world and international trade. PRA (Pest risk analysis) has been done actively on fruits and vegetables, pest free area has been delimited according to the international standard,which have minimized negative trade effects of plant quarantine on trade,and accelerated the development of import and export trade of fruits and vegetables.