The paper deals with the possibility of adopting cultural and biological control in pest management towards sustainable agriculture on the bases of author's experience in IPM practice.China is rich in natural resources of beneficial insects. Chinese farmers possess the traditional experience of cultivation in agriculture management. So conservation and augmentation of natural enemies are deliberate action to protect and maintain natural enemy populations or to increase their beneficial effect in the agroecosystems. Biological control fits comfortably into sustainable agriculture. The low-input, sustainable insect pest management is promising in China as well. The application and spread of biological control contribute to the development of sustainable pest management. The alter-natives include the cultural management and plant resistance to insect pest, biotechnology for engineering, selecting and releasing parasitoids and predators, utilization of semiochemicals or natural products, the application of physiological and ecological selective pesticides. Mathematical modeling and systems analysis are to be expected to the integrated pest management. Interface of biological control with the basic sciences of entomology and education in pest management for farmers are nec-essary.

Induction of carboxylesterase (CarEs) by insecticides and plant allelochemicals and de velopmental changes of CarEs were investigated during 1992-1996 in cotton boilworms, Helicover pa armigera (Hubner). The specific activities of midgut CarEs increased slowly before 5th day and then rose rapidly in larvae. The specific activity started to reduce from 8th day larvae to prepupae and then rose again. E2, E4, E5, E.6, E7 and E9 activities in nine isoenzyme hands obtained by polyacrylamide gel electrophoresis were higher using β-naphthyl acetate than a-naphthyl acetate as substrate, whereas El, E3 and E8 activities were reversed. Parathion, malathion, fenthion, SV1,methomyl and deltamethrin at sublethal dosage made the total activities of CarEs reduce, but malathion induced the activities of E4 and E5 in six isoenzyme bands at 48h after treatment by malathion and depressed the activities of El, E2, E3 and E6. Plant allelochemicals, rutin, quercetin and 2-tridaconone, can significantly induced Care activities of larvae.

The inhibition of 22 organophosphates (OP) to the activity of carboxylesterase, usinga-and β-naphthyl acetate as substrate separately, was investigated in cotton bollworms ( Helicoverpaarmigera ). The inhibition potential of paraoxon, dichlorvos, SV1, quinalphos, malaoxon, IBP were much stronger than the other insecticides tested. The relationship between chemical structureand the inhibition potential to carboxylesterase was also studied. The inhibition potential was: phosphate > phosphorothionate, phosphorothiolate > phosphorodithioate, phosphoramidate > phosphorothiolamidate and (C2H5O)2OP > (CH3O)2OP.

Body distribution and partial purification of acetylcholinesterase (ACHE) were investigated in cotton bollworm, Helicoverpa armigera (H(ibner). The head, thorax and abdomen possessed 78.2 96, 17.9 96 and 3.9 96 of total ACHE activities in the 7th-day adult, while in the sixth instar larva, the percentages were 90.3 %, 6.5 % and 3.2 % respectively. Eighteen times of the purified factors in ACHE ctivities were obtained by Sephardex G-200, but only four times by Sepharose 4B in column chromatography. The purified factors of ACHE were higher with Triton X-l00 than without Triton X-100 in eluant.

The properties of carboxylesterase and insecticide resistance were investigated in diamondback moth (DBM), Plutella scylostella collected from Wuhan, Hubei Province and Zhangjiakou, Hebei Province during 1995 to 1997. The resistant levels of Zhangjiakou population to avermectin, malathion, hexafiumuron and deltamethrin were 1.8, 2.9, 0.5 and 1.7-folds and that of Wuhan population were 4.3, 2.2, 3.2 and 2.4-folds respectively, compared with the susceptible strain. There was significant difference in carboxylesterase (CarE) activity among larvae of the above two field populations and one susceptible strain and no difference in Care activity among the adults of the above three populations, when a-naphthyl acetate (a-NA) or β-naphthyl acetate (β-NA) was used as substrate. The affinity of Care toward a-NA was almost same as that toward β-NA in larvae of the two field populations, but the affinity of Care was much higher toward a-NA than toward β-NA in susceptible strain. Inhibition on Care by SV1 and paraoxon was much stronger in susceptible strain than in Wuhan population.

The resistance selection and patterns of cross-resistance of diamondback moth (DBM),Plutella xylostella (L.), to chlorfluazuron, a benzoylphenylurea (BPU) insect growth regulator(IGR) that interferes with chitin synthesis, were investigated during 1995-1996. Laboratory selection of a Shenzhen strain (SZ-S) of DBM, having been reared in laboratory for 6 years since itscollection in 1990, by chlorfluazuron for 6 generations resulted in 23.78-fold resistance to chlorfluazuron, and quick reversion to susceptibility was observed when the culture was kept without exposure to the chemical pressure. Cross-resistance to conventional insecticides cyhalothrin, cypermethrin, phoxim, quinalphos, methomyl, microbial insecticide Bt, abamectin and diafenthiuron wasnot apparent. Negative cross-resistance was demonstrated to two nereistoxin derivatives, cartap(0.21) and shachongdan (0.23) . The results of in vivo tests showed that addition of PBO or TPP had no effect on the toxicity of chlorfluazuron in the SZ-S strain, while PBO or TPP significantly increased the toxicity of chlorflu-azuron in both SH-R and CH-R strains, with synergism ratios ranged from 15.42 to 29.71-fold and 2.74 to 2.87-fold based on comparison of LCs0 and PBO restored the effectiveness of chlorfluazuroncompletely, indicating that MFO is the major resistance mechanism.

The mechanisms of chlorfluazuron resistance in diamondback moth (DBM) (PluteUa xylostella L. ) were investigated in a chlorfluazuron-selected strain (CH-R) and a field population collected from Shanghai (SH-R) in October 1996, with 9.16-folds resistance to chlorfluazuron.The results showed that: (1)' The activities of MFO in O-demethylation increased 2.00 and 1.08-folds in CH-R and SH-R strains, respectively, compared with the SZ-S strain. (2) There were differences in quality and quantity of Care between CH-R and SZ-S strains. The K_m value of CH-R strain was 20.46 times lower than that of the SZ-S strain, suggesting that the property of Care inCH-R strain was altered. But there was no significant difference between SH-R and SZ-S strains in K_m and Vmax values. (3) Difference of phosphatase activities between SZ-S and CH-R or SH-Rstrains was not significant. (4) The activities of cuticle chitinase and phenol oxidase were decreasedby 48% and 60%, respectively, compared with the SZ-S strain.

The biochemical and toxicological properties of carboxylesterase (CarE) were investigated in Trichogramma dendrolimi and T. chilonis. The optimal reaction time of Care with a-NA was 40 minutes. The Care activity mainly distributed in 0-1OD/(mg.min)in T. dendrolimi and1-4OD/(mg. Rain)in T. chilonis respectively. The comparison of Michaelis constants (K_m) ofCare between T. dendrolimi and T. chilonis indicated that the affinity of the latter to substrate was stronger than that of the former. There was no significant difference of Care inhibition between T. denclrolimi and T. chilonis when used paraoxon as inhibitor. The inhibition of paraoxon to the carboxylesterase of T. dendrolimi was much stronger than that of TPP.

Semiochemicals perform the key physiological functions in the course of interactions between insects and plants. Bioassay studies showed that the avoidance of tomato plant from oviposition by cabbage butterfly was proved to be attributed to the presence of water-soluble deterrent which could be extracted by ethanol. Oviposition deterrent indices (ODI) of the ethanol extract (Ee) were 87.4 % and 80.9 % respectively in the first day and third day after treatment, both were statistically significant . The active water-soluble fractions when applied on cabbages not only significantly reduced the amount of eggs laid on the cabbage leaves, but also strongly disturbed their normal oviposition behavior in contrast to the controls. Net-house tests showed that a formulation of the active water-soluble components with Tween-80 (Ee+0.1% Tween-80) may be hopeful to be developed as an 0viposition-deterrent which keeps effective for more than a week when applied on cabbages.

Diapause of prepupae of the alfalfa leafcutter bee, Megachile rotundata (F.) is mainly controlled by both photoperiod and temperature. A main factor for female is the photoperiodical vari-ation that decides whether progeny prepupae will enter diapause or not. For immature stages, especially from late instar (about third instar) to prepupae, temperature variation has a greater effect onprepupa diapause. During this stage, if the temperature is below (21.09±1.03)12, more than 50 percent prepupae will enter diapause. In addition, the latitude of the area bees being released in and the generation of the bee also have an important influence on prepupae's diapause.

Releasing experiments of the parasite, Trichogramma chilonis, for control of the cot ton bollworm Helicoverpa armigera were conducted in cotton fields in Yucheng, Shandong Province in 1994 and 1995. The results indicated that: the effective dispersal distance (EDD) of T. chilonis was positively related to both the length of sunshine and the average field temperature (AFT) duringthe releasing periods. When the temperature was higher than 24℃, most of the patasites dispersed beyond 25 m and when it was lower than 20.7℃, all of them distributed within 1-25 m. During June-August, their EDD varied from 10 m to 25 m. Rairffall severely influenced their EDD and parasitizing rate. EDD of the egg parasite showed a significant negative correlation with the field relative humudity (FRH), when FRH was above 89% their EDD became greatly shortened and most of them distributed near the releasing site.

The dispersal direction of T. Chilonis in relation to wind speed and direction was investigated in cotton fields in Yucheng, Shandong Province in 1994 and 1995. The results showed that: (1) When the average wind speed (AWS) ranged from 1.1 rn/s to 1.6 m/s, the main dispersal direction was down the wind; when AWS was between 0.9 m/s and 1.1 m/s, the main dispersal direction was up the wind; and when it was about 0.6 m/s, there was no difference among the eight directions. (2) During the second generation of the cotton boUworm (before early July), the main despersal directions of T. chilonis were southwest and northwest; during the third genera tion before August, there was no main dispersal direction of the parasite; during the fourth generation (after the middle of August), the main dispersal directions were east, northeast and north.(3) Among all of the releasing experiments, the most urdavourable directions for dispersal of theparasite were west and south.

In 1992- 1995, investigation on apple insect pests and their natural enemies in fourdifferent apple orchard ecosystems was systematically carried out in Beijing, the results showed that the density of predators on the apple trees in cover cropping system was higher than non-tiUage or clean cultivated system. Increasing plant diversity in apple orchard ecosystems plays an important role in stabilizing the beneficial enemies. The number of predators on the apple trees in cover cropping system was higher, and the peak population density of mites or aphids or leaf miners was lower than the non-tillage system and clean cultivated system. During the last two years' the predators and parasitoids had controlled the secondary inducedpests, such as spider - mites, aphids and leaf miners, eliminating any need for pesticide applications. The ratio of parasitized Lithocolletis rignoniella Mats in cover cropped system was 62.7 %, which was 1.34 times as large as in the non-tillaged system and 16.9 times as large as in the light planting clean cultivated system and 17.9 times as large as in the combine planting clean cultivated system. A new design of cover cropping system consisted of two beneficial weeds, the Lagopsis supina and Hemistepta lyrata Bunge under the canopy of tree, instead of the chinese rape and cover crop,the alfalfa, in the row of apple trees. In comparison with the past cover cropping system, the population density of predators on cover crops in the 3rd year after new cover cropping system was 12.5times as large as in the first year. The density of predators on apple trees was evidently increased. The predator/prey ratio was changed from 1:34.9 in the first year after new cover cropping systemto 1: 14.4 in the second year after new cropping system, the result was equal to the ratio in the 5th year after the past cover cropping system.

Community structure of carabids and spiders in agricultural landscape was investigated by pitfall traps in suburb of Qianjiang city, Hubei Province from June to October, 1995. The results indicate that 5 landscape elements have significant role in preservation of carabids and spiders.（1） In margins of rice fields, diversity index and species of carabids and spiders were the highest. 2)In crop-forest interval fields, evenness of carabids and spiders was the highest, diversity index was second. 3) flood fields in which no insecticide was applied had high number of carabids and spiders.The dominant species are Pheropsophus javanus , P . Jessoensis and Padosa astrigera respectively.（4) Dry farmlands in which minor insecticides were applied had high number of carabids. The maincarabids is Leistus magnus. 5) Home gardens existed large number of spider. The dominant spiders is Padosa laura. Correspondence analysis shows correspondent relationships between landscape elements and dominant species of carabids and spider, between conventional farm lands and the 5 landscape elements mentioned above. The results provide reference for design and management of agriculture landscape.

Dociostaurus kraussi is the dominant species in Xinjiang rangeland. In 1989, Dociostauras kraussi entomopoxvirus (DkEPV) was first isolated from Dociostaurus kraussi in Manas,Xinjiang Automonous Region. In 1992, it was found in Barkol, Xinjiang, too. The natural epidemic rate of it was 23.3 %. DkEPV was found to infect mainly the fat body. Occlusion bodies are spheroidal with diameter of 2-7μm, very different in size. The virions obtained from the occlusion body are brick-shaped or ovoid, 144- 269 nm in size. The surface of a virion has a mulberry-like structure. DkEPV showed the typical ultraviolet absorption spectrum of nucleic acid. The Tm ofDkEPV-DNA is about 79.0Y3 based on the thermal denaturation curve, and its G+C content is about 17.8 %. Restriction endonuclease analysis reveals that EcoR I, Bgl II and Hind III digestedthe DkEPV-DNA into 29, 21 and 18 DNA fragments, respectively. Taking λDNA Hind III fragments as standard for molecular weight measurement, the molecular weights of these DNA fragments are 155. 45 x 10⁶ 155.69 x 10⁶ and 155.40 x 10^{6 daltons, repectively, and the total molecular weight is 155.5 x 106 daltons.}

With electron microscope, most of the occlusion bodies of CiEPV are ellipictal in shape, some are square-round. They vary greatly in size. The virions are oval and mulberry-like in appearance. The core of the virion is cylindrical. From the longitudinal section , its inner ropelike structure folds back 2 or 3 times and from its cross section, 2 or 3 dots can be observed. The lateral body is also cylindrical and symmetrically encloses the nucleocapsid. This viral DNA, when cleaved with restriction enzyme EcoR I, produces 16 DNA fragments.The molecular weight of this DNA is 135.7×10⁶ daltons. Degradation of the occlusion body of CiEPV is faster than that of OaEPV under the same condition. When the temperature is constant at 37℃ and pH ranges within 9-11.5, with the higherpH, the degradation of occlusion body becomes faster. When the pH is constant at 11.2 and the temperature ranges within 25-40℃, with the higher temperature, the degradation of occlusion body becomes faster.

The induction of plant allelochemicals on the cotton bollworm tolerance to in secticides was investigated using the method of mixture of plant allelochemicals and artificial diets. The insecticide tolerance of F_l, F₂ or F₃ generation population of cotton bollworms fed on the artificial diet containing rutin was stronger than that of the population fed on onlyartificial diet, while the susceptibility of Fa generation population to insecticides was almost the same with that of the artificial diet-fed population. The susceptibilities of the quercetin fed F_l and F₂ and the 2-tridecanone-fed F_l generation populations to methyl parathion reduced significantly compared with the artificial diet-fed population. However, there was no difference of susceptibility to methomyl and deltamethrin between the quercetin- or 2-tridecanone-fed population and the artificial diet-fed population.

The rate of infection of Nosema locustae decreased with the decrease of densities of the complex population of rangeland grasshoppers in the treated season (as Plot 1).However, the rate of infection of N. locustae in Myrmeleotettix palpalis, one of the dominant species of grasshoppers occurred lately in the season, increased with its increase in number in the complex population. The spatial distribution of infected grasshoppers by N. locus-tae in the treated season, varied with sampling time. On the 7th days after treatment with N. locustae bait (7.5 x 10⁹ spores/1.5 kg wheat bran/ha), the spatial distributions fixed to the Poisson distribution. But on the 28th and 40th days fixed to aggregate distributions. The densities of complex grasshoppers population were correlated with the percentages of infection of N. locustae in August of 1993 and August of 1994 in the plots, where were treated with N. locustae in 1988 and 1989 respectively (as Plot 2 and Plot 3). Further analysis of the data from the plots showed that both densities and infections in 1993 were significantly higher than that in 1994. And N. locustae still distributed widely in most of dominant species of grasshoppers, Oedaleus asiaticus, M. palpalis, Bryodema luctuosum luctuosum, Angaracris spp. And Dasyhippus barbipes. The spatial distribution of infected grasshoppers by N. locustae both in 1993 and 1994 were suitable to Poisson distribution in Plot I and Plot 2. The dispersal distance and directions of N. locustae were investigated in1993 and 1994 in the two plots too. The results indicated that the dispersal distance of N.Locustae was at least 1000 meters, and the dispersal direction might be affected by the geographic features and the prevalent wind etc.

12# Bt/CXC is an engineered endophytic bacterium by introducing thecrylA? gene from Bacillus thuringiensis subsp, kurstaki into the chromosome of Clavibacter xyli subsp, cynodontis, which colonizes the vascular system of corn. Bioassays withcorn borer (Ostrinia furnacalis) was conducted and the results showed: at each concentration level, strain 12# had a higher insecticidal activity than Bt strain HD-73 and PBStreated control, causing 63 % mortality at the highest concentration tested, while the mortality rate of larvae ingesting wild-type HD-73 was 53% at the same concentration. Theconcentration-mortality curves of the two strains showed a linear correlation. Strain 12#'scoefficent was bigger than that of HD-73. In planta bioassays, the results showed that in-secticidal activity of corn injected with 12# was obviously better than that of corn seed-treated with 12#. At different injection concentrations, larval mortality waved from 70% to96 96, which were significantly different from those of PBS control. At the same time,strain 12# restrained the development of corn borer so that weight of living larvae were reduced by 26.4 % to 44.5 %. Larvae which lived with inoculated corn did not develop to second instar, while those lived with control developed to four instal.

The control effects of several compound trap measures on cotton bollworm(CBW), Helicoverpa armigera (Hubner), including double wave lamp, high pressure mercury vapour lamp with sex pheromone or poplar branches-bundle trap respctively, were evaluated in cotton field in Linqing, Shandong Province, China in 1995. The main results were asfollows: The compound traps combining two different lamps with sex pheromone or poplarbranches-bundle show obvious control effect on CBW moths. The control effect is affected bythe quantity of the CBW population in the field, I. E. when a relative large quantity of CBWpopulation occurs in a generation, their control effect could have some good result, but whenthe quantity of the CBW population in the field is far beyond the ordinary level it gets smallerthan it should. After analyzing the CBW moth catches, the numbers of eggs, larvae and natural enemies in 100 individual cotton plant for each compound treatment in field comprehensively, the results indicate that the compound trap combining high pressure mercury vapourlamp with sex pheromone has the best control effect, double wave lamp with sex pheromonecomes second. Comparing with control, the number of eggs in 100 individual cotton plants in the treatment region of compound trap combining high pressure mercury vapour lamp withsex pheromone and compound trap combining double wave lamp with sex pheromone can bereduced to 34.5 96 and 28.6 % within 160m respectively.

Mathematical morphology is a subject using mathematical methods to describeor analyze the shape of an object. Facilitated by computer science and technology in rapid development, mathematical morphology has been paid more and more attentions in image processing and pattern recognition field. However, its applications in biology are still sparse and needed to enhance. A new interdisciplinary branch, mathematical insect morphology, is in troduced in this paper. It includes three aspects: 1. Technological study of mathematical insect morphology, involving digitization, processing and recognition technique of insect images; 2. Theoretical research of mathematical insect morphology on understanding of insectimages and the relationship with insect taxonomy; and 3. Practical applications of mathematical insect morphology, starting with the development of databases and analytical software ofmathematical morphological data from insect research, and looking forward to the development of computer vision and machine learning of insect images. Besides, mathematical insectmorphology will have so many applicable fields such as to develop automatic pest monitoring system or multimedia expert system of insect identification in the near future.

This paper introduces methods for acquisition and processing of entomologicalmultimedia information. The necessary software and hardware environment in the multimedia developing procedure has been presented in detail, containing the input and processing of text, the recording and processing of sound, the making of digital video and digital imageswhich include the entomological photographing, image scanning and image processing.

Having studied on long-term regular occurrence patterns of main insect pests oncrops such as Mythimna separata Walker, Nilaparvata lugens StOl, Cnaphalocrocis medihalls Guenee, Chilo suppressalis Walker, Tryporyza incertulas Walker, Schizaphisgraminum Rondani, Ostrinia furnacalis Guenee and Helicoverpar arrnigera Hiibner etc.,it was discovered that the periodicity of pest occurrence for M. separata, C. suppressalis,N. lugens, C. medinalis and O. furnacalis was 16 years approximately. A periodicity of about 12 years also occurred in N. lugens, T. incertulas. An approximately 11 years periodicity for C. suppressalis, C. medinalis, S. graminum and H. armigera was found.A forecast of the trend of the pests for 1996-2000 years is presented.

Seven species of genus Isyndus Still from China are recognized, keyed, redescribed, and illustrated with 76 figures. Isyndus brevispinus Breddin, I. Lativentris Distant, and I. Pilosipes Reuter are treated as valid and/or distinct species. I. Sinicus Hsiao etRen and I. Yunnananus Ren are proposed to be the synonyms of I. Pilosipes Reuter and I.Lativentris Distant respectively. Isyndus brevispinus Breddin is newly recorded from China.All measurements are in millimetres.

This paper deals with six new species of the family Dolichopodidae (Diptera) from China.Type specimens are deposited in the Insect Collections of China Agricultural University (CAU) andInstitute of Zoology, Academia Sinica (IZAS).

Three new species and four new records from north China are described in this paper. Genus Helicoconis is reported in China for the first time. All the type specimens arekept in the Insect Collections of China Agricultural University.

The present paper deals with one new species and two new records of Liposcelisfrom China. Liposcelis yangi is described as new. Liposcelis brunnea and Liposcelis pallensare redescribed and illustrated. The type of new species is deposited in the Insect Collectionsof China Agricultural University.

This paper presents one new species in Zhejiang Province, China. The speci-men is deposited in the Insect Collections of the China Agricultural University.Loxoeera tianmuensis, sp. Nov. (Fig. 1-2) Body length: 6.5 mm; wing length: 5 mm. Head black, only apical margin of frons light brown. Gena red-yellow. 1st and 3rd antennal segments black, 2nd segment light brown. Arista yellow and pubescent, loc, or,vte, vti and pvt absent. Mesonotum in anterior part, humeri and scutellum black. Posteriorpart of mesonotum red-yellow with black stripes (Fig. 1); Pleura in upper part black, inlower part red-yellow; metanotum black; Isa, lsc, n, pa, and de absent; wing hyaline withlight brownish spots in middle and apical parts (Fig. 2). Halter and legs yellow. Abdomenblack, only last segment red-yellow with darkened dorsum. Holotype ♂, Zhejiang: Mt. West Tianmu, 1987-IX-3, Maqun.