The polydnavirus of Cotesia plutellae (Hymenoptera: Braconidae) was characterized and its physiological effects on the host larvae of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae) were studied in this paper. The results showed that the virion of polydnaviruses (PDVs) in the calyx region of female ovary had a tail and multiple nucleocapsids (up to 16) enveloped; the nucleocapsid measured 40-168 nm in length and 39-40 nm in diameter; PDVs replicated only in calyx cells that underwent lysis after replication completed; the calyx fluid was injected into the host larval haemocoel while female wasps laid eggs; large numbers of PDV virions were observed along the sheaths of the host tissues; it appeared that PDVs emerged from their envelopes first, and then infected the host tissues. When 2nd, 3rd and early 4th instar host larvae were parasitized by female wasps irradiated with Co⁶⁰ (resulting in pseudoparasitism), almost all of them were not able to pupate, but the period of the last instar larvae was significantly prolonged and a pair of brown short wing buds appeared on the thorax of host larvae at the end of the last instar; however, when host larvae of the late 4th instar were pseudoparasitized, and even if super-pseudoparasitized 9 times, they were still able to normally pupate, but not able to emerge. These results suggest that the PDVs and venom could prolong the developmental period of host larvae under conditions where there were no parasitoid eggs hatching, no teratocytes released and no parasitoid larvae present, but they seemed to have limited effect on the late 4th instar larvae. The numbers and micromorphology pattern of fat bodies of host larvae pseudoparasitized by the irradiated female wasps were distinctly different from those of normally parasitized hosts, suggesting that the teratocytes and parasitoid larvae may have some effects on the fat bodies of host larvae.

Dendrolimus punctatus cytoplasmic polyhedrosis virus strain Hunan (DpCPV-HN) was cloned in vivo and identified as a type 1 cypovirus. Fourth-or 5th day posthatching F₁ and F₂ silkworms from an generation F₁ that had previously been infected by DpCPV-HN, and two other type 1 cypoviruses from Bombyx mori(BmCPV-1) and D. punctatus(DpCPV-HN) were selected for the infection test. The results indicate that the breed of B. mori tested in this study was very sensitive to BmCPV-1, and could also be infected by DpCPV-HN. Based on the accumulative total mortalities of F₁ and F₂ generations of B. mori infected by DpCPV-HN over 28 days post-infection，the 50% lethal doses (LD50) of DpCPV-HN of F₁ and F₂ generations were 885 and 18 CPBs respectively. Obviously, the F₂ silkworm larvae from DpCPV infected generation F₁ were more sensitive to DpCPV-HN than those of the F₁ generation. However, the sensitivity of the F₂ generation to DpCPV-HN was still inferior to that of the F₁ to BmCPV-1. To some degree, the ratio of cocoons，ratio of pupae，ratio of moths to pupae, cocoon weight, cocoon shell weight, ratio of cocoon shell weight, and number of eggs from single female moths of the F₁ and F₂ generations were affected after infection by DpCPV-HN. The correlations between cocoon weight, cocoon shell weight, ratio of cocoon shell weight，number of eggs from single female moths of silkworms and inoculation doses of DpCPVHN were not obvious.

Celangulin Ⅴ isolated from the root bark of Celastrus angulatus Max. is a new kind of insecticidal compound. The effects of celangulin Ⅴ on the muscle cells of Mythimna separata were determined with electron microscopy observation. It was found that celangulin Ⅴ had a myotoxic effect on the adult flight muscles and larval skeletal muscles of M.separata. The sarcolemma and inner membrane were disrupted and mitochondria became wollen,vacuolated and disintegrated. The space between myofibrils and mitochondria significantly increased, the sarcoplasmic reticulum spread and pith tissue occurred, the nucleus became swollen, nucleoplasm concentrated and the nuclear membrane disrupted, the space around trachea enlarged and sarcomeres contracted abruptly. These results suggest that the sarcolemma and inner membrane might be the target acted on by celangulin Ⅴ.

Environmental scanning electron microscopy and biochemical techniques were employed to analyze the structure of the normal and fluorescent brightener 28(M2R) treated peritrophic membrane(PM) of Spodoptera exigua. The normal PM surface was smooth and wrinkled without pores or slits while the treated PM surface had pores and slits.There were many types of protein in the PM. SDS-PAGE separation of the PM suggest that there are at least 17 polypetides,most of them less than 97.4kD. Proteins formed 41.98% of the total mass of the PM and carbohydrates 2.05%. The PM proteins could be dissociated from the PM in vitro by M2R. Droplet feeding fifth instar larvae with M2R greatly increased the permeability of the PM.

The histological structures of the dung beetle, Copris ochus Motschulsky integument was studied by microscope. There are collagenous fiber in body integument especially the ventral integument and the hymenopterous integument discovered by the H.E. and Mallory's staining. Also cavity in the elytra was found, which are supported by pier-formed pillars formed by integument sinking for supporting and reducing weight. There are cavities in the hymenoptera which are full of the brown fat glands and their secretion. The dermal cells were found in the cavities of the elytra and hymenopterous wing which suggest that the elytra and the hymenopterous wing are living structures. A lot of the brown fat glands are surrounding the muscle in the leg to provide energy and decreasing friction between muscles. There are a lot of protrusions, setae and pore canals of different diameters communicating with the outside of the body. Those structures and lots of the oil-glands with their secretions provide the orphological and chemical basis for decreasing the integument stickiness.

The effects of vitamin B₆ (VB₆) deficiency on the amino acid metabolism, fatty acid metabolism and aminotransferase activity of the silkworm, Bombyx mori, were studied in newly ecdysed 5th instar larvae reared on a semisynthetic diet that contained no mulberry powder and in which vitaminfree casein was the protein source. Under VB₆deficient conditions, larval growth was retarded, the catabolism of branched chain amino acid (leucine, valine, isoleucine) was inhibited, and lysine catabolism was stimulated. The leucine, valine, isoleucine and serine content in haemolymph were markedly increased by VB₆ deficiency. Conversely, lysine, proline, arginine, methionine and glutamine content decreased, especially markedly in lysine. The lack of dietary VB₆ also inhibited synthetic metabolism of fatty acids and reduced the activity of glutamic pyruvic transaminase.

The effects of moulting by nymphs of the green peach aphid, Myzus persicae on the virulence of Beauveria bassiana BBSG8702, was bioassayed in the laboratory. At 21℃ and with a conidial suspension of 1×10⁶/mL, aphids inoculated with the fungus at the 1st, 2nd, 3rd or 4thinstar suffered 10.1%, 2.1%, 3.1% and 40.2% cumulative mortality respectively, significantly lower than that observed in the aphids inoculated at the adult stage (98.4%). Among the individuals that eventually died of the infection following inoculation at the 1st, 2nd, 3rd or 4th instar, 8.1%, 50.0%, 44.4% and 98.0% of them developed to adulthood and produced healthy offspring prior to death. Mortality of the aphids inoculated with the fungus at the nymphal stages was closely related to the time interval between inoculation and first moult post-inoculatIon; the earlier the moult, the lower the mortality. A small proportion of infected nymphs, especially those infected at early instars, died before the next moult post-inoculation. Detailed observations were made on the development, survival and reproduction of aphids inoculated with the fungus during the very arly stage of the 1st or the 4th instar, stages when nymphs were most susceptible to fungal infection. Compared to the duration of normal nymphal development, nymphs inoculated with the fungus had slightly shorter (<5%) development times for the instar in which they were inoculated. Pre-adult mortality caused by the infection was only 4.1% and 0 when the aphids were inoculated with the fungus at the early 1st and 4th instar respectively. Moreover, the reproductive rates of those Infected aphids that eventually died at the adult stage due to the fungus during the first 8 days of their adult life were similar to controls not inoculated. These findings demonstrate that moulting by this aphid, especially multiple moulting by the aphids following infection with B. bassiana at an early nymphal stage, Is an effective mechanism for avoiding or delaying infection by this fungus, and thereby reduces the virulence of the fungus.

Four Zoophthora radicans (Entomophthorales) isolates from different hosts were bioassayed against the second instar larvae of the diamondback moth, Plutella xylostella in the laboratory. Each isolate included eight dosages resulting from spore showers at different times. On day 8 after exposure to a spore shower for Inoculation, a P. xylostella derived isolate, ARSEF1100, caused a cumulative mortality of 2.38%－97.44% at 0.53－319.32 conidia/mm² with all cadavers exhibiting typical Zoophthora syndrome. Two isolates derived from Empoasca, ARSEF2699 and F99101, killed 2.38%－50.00% and 2.38%－57.89% at 1.56－314.84 and 1.84－484.08 conidia/mm², respectively, whereas the isolate ARSEF1342 from Pieris brassicae，killed only 6.52%－13.63% at 3.54－633.40 conidia/mm². Typical Zoophthora syndrome was observed only in approximately one third of cadavers killed by the latter three isolates. Fitting the data to a time-dose-mortality model generated the estimates of parameters for time and dose effects of each isolate. The parameter estimates for dose effect (β) was 1.89 for ARSEF1100, 1.48 for F99101, 1.23 for ARSEF2699, and 0.37 for ARSEF1342, which are significantly different. The LD₅₀ values estimated for ARSEF1100 were 231.68，113.08, 71.41, 40.87 and 35.30 conidia/mm² on days 4－8 after exposure, respectively. The corresponding estimates were 1 344.43，922.39，555.58，410.06 and 397.07 conidia/mm² for ARSEF2699, and 666.86，451.64，413.82，350.65 and 332.57 conidia/mm² for F99101. The virulence for ARSEF1342 was too weak for its LD₅₀ to be estimated. The isolate ARSEF1100 was the most virulent to P. xylostella, and can be considered as a microbial agent for control of the pest.

The community of arthropods in rice paddy was divided on the basis of nutritional relationships into five guilds, i.e., phytophages, parasitoids, predators, detritivores and others, and the effects of two indica lines (TT9.3 and TT9.4) of transgenic Bacillus thuringiensis rice (Bt rice) with a fused gene of cry1Ab/cry1Ac on this community were investigated and evaluated in terms of guild dominance, family composition and dominance, as well as the usual indices, at four locations for two years. The control community was that of an untransformed (IR72) rice crop. Significant differences in the dominance of some superior families in phytophagous, parasitoid and detritivorous guilds were found between Bt rice plots and the control. For example, the dominance of the Braconidae and Ichneumonidae in Bt rice plots was sometimes markedly lower than in the control. In most cases, however, there were no significant differences in guild dominance, family composition and dominance or common community indices such as species richness, Shannon-Wiener diversity index, evenness index and dominance index. The temporal dynamics of Bt rice plots and the control were also similar. Meanwhile, most of the dissimilarities between phytophagous sub-communities, parasitoid sub-communities, predator sub-communities and arthropod communities as a whole in Bt rice plots and the control were apparently low. It was apparent that planting of Bt rice generally did not have any marked negative effect on the rice paddy arthropod community.

he effects of insecticide application on loblolly pine mealybug, Oracella acuta (Lobdell) (Homoptera: Pseudococcidae) and its two dominant parasitoids, Allotropa sp. (Hymenoptera: Platygastridae) and Zarhopalus debarri Sun (Hymenoptera: Encyrtidae), were investigated using yellow sticky traps. The results revealed that the Oracella population responded positively to the intensity of insecticide use, which had adverse effects on its two parasitoids. In fact, the outbreak of the mealybug was largely due to this adverse effect of insecticides on its parasitoids. Orchards with high intensity use of insecticides resulted higher Oracella population and vice versa. Comparison of three orchards with three levels of insecticide use further demonstrated the effectiveness of the parasitoids in regulating mealybug populations. Significantly more males of Zarhopalus sp. Were caught than females indicated a sex preference for yellow in this species. A strong positive correlation exists between Oracella and its parasitoids but this relationship can be disrupted by the heavy use of insecticides.

Epiblema strenuana is a gall inducing lepidopteran that was introduced into China as a biological control agent against ragweed, Ambrosia artemisiifolia. In Linxiang, Hunan Province, E. strenuana feeds on two species of host plants, A. artemisiifolia and Xanthium sibiricum. Ostrinia orientalis, an endemic insect that originally fed on X. sibiricum, is also a borer of A. artemissifolia. In order to assess the ecological impact of E. strenuana where it has been released, especially in locations where it coexists with O. orientalis on A. artemissifolia, a factorial design was used to conduct an experiment in a field cage. The results showed that both E. strenuana and O. orientalis reduced the biomass, seed production and height of the host plant. Biomass was reduced maximally by 94.3% in host plants with a 1.0 cm main stem following inoculation with 63. larvae of E. strenuana and 8 larvae of O. orientalis. Plant height was reduced maximally by 31.7% when 17 larvae of E. strenuana and 8 larvae of O. orientalis were inoculated on plants with a stem diameter of 1.0 cm. Seed production was reduced maximally by 99.3% when 40 larvae of E. strenuana and 5 larvae of O. orientalis were introduced onto a plant with a 0.7 cm main stem diameter. When 40 larvae of E. strenuana and 5 larvae of O. orientalis were inoculated on the host plant with a 2.1 cm main stem diameter, biomass and seed production were reduced by 2.0% and 6.1% respectively, but height increased by 2.4% Control efficiency decreased as the host plant grew because of the increasing capacity for compensatory plant growth. Feeding impact on the biomass, seed production and the height of the host plant, A. artemisiifolia exceeded compensatory growth during the early growth of the plant (main stem < 0.7 cm), but the situation was reversed in the oldest plants. The impact of E. strenuana on seed production was greater than O. orientalis, while the impact of O. orientalis on biomass and plant height was greater than E. strenuana. Furthermore, when these two Insects fed on A. artemisiifolia at the same time, their feeding behavior was independent, and no undesired consequences occurred. In order to utilize these two biocontrol agents efficiently, the insects should be introduced onto the target weeds during the early developmental stages of the host plant.

he teleconnection between population density (egg counts) of cotton bollworm (CBW), Helicoverpa armigera （Hübner）, and the anomaly of monthly mean sea surface temperature (SST) in the North Pacific was analyzed to find the significant (P<0.05) correlative key factors with large and sustainable spatiotemporal extension to build longterm forecast models for Helicoverpa outbreaks. Based on the CBW data over 26 years (1974-1999) in Yuncheng, Shangdong Province, over 22 years (1978-1999) in Dezhou, Shandong Province, and over 20 years(1980-1999) in Fengxian, Jiangsu Province, optimum forecast models were established for longterm prediction of the 3rd generation eggs in Yuncheng and Dezhou, and the 2nd generation eggs in Fengxian. The results indicated:（1）There was significant (P<0.05) or highly significant (P<0.01) teleconnection between the fluctuation of CBW populations and SST in the North Pacific. The location and range of the significant correlated areas varied with time, but there were a few such significantly correlated areas, relatively stable in space and sustainable in time. （2）There was a vast region in the North Pacific of significantly correlated (P<0.001 in center) with the CBW eggs counts of the 3rd generation in Yuncheng, the 2nd generation in Fengxian and the SST in January 2 years ago, which ranged from 35°N to 55°N, 135°E to 135°W and sustained for 4 months. But the area for the 3rd generation eggs in Dezhou was located at the low latitude Northern Pacific (1°-17°N，165°E-120°W) during July to September 2 years ago.（3）The evaluation of models with the drive variable of the average of the mean SST departures on each grid within the significant correlative areas from January to November of the year before last showed that the predictive accordant rates for the egg counts of the 3rd generation CBW in Yuncheng and Dezhou, and the 2nd generation in Fengxian were correct in 5 of the 6 verified years (1994-1999) for Yuncheng, correct in all 5 years (1995-1999) for Dezhou and in 3 of 5 years (1995-1999) for Fengxian respectively. The results suggested the possibility to make forecast of CBW outbreaks about 20-27 months earlier with these models.

Understanding flight behavior is basic to the study of insect migration. We investigated the flight activity and capacity of the cotton aphid, Aphis gossypii, in Nanjing, Jiangsu Province. Insects were captured using yellowbasin traps placed on the top of a 20 m high building. Ovaries of trapped females were dissected and aphids collected from Hibiscus syriacus trees for tethered flight tests In spring, summer and autumn. The results show that the daily emergence peaks of alates occurred between 19:00 and 20:00.There were two migration peaks, occurring on 8 May and 25 October in 2001. 95.7% of female aphids trapped in basin traps in May had < 7 ovarioles. However, 35.2% of alate aphids captured on H. Syriacus had > 7 ovarioles. The average number of ovarioles in alate aphidstrapped in basin traps (3.94±1.65) and on H. syriacus trees (5.88±1.92) were significantly different. In cotton fields, alate aphids flying low in the sky were observed from middle to late August, 2001 These had < 6 ovarioles. Flight behaviour was not observed in aphids with > 6 ovarioles. The flight capacity of cotton aphids was measured using tethered flight tests. The results show that the flying rate and the average flight distance were greater in spring and autumn than in summer. Maximum flight distances in spring, summer and autumn were 3.89 km, 1.44 km and 6.15 km, respectively.

ating behavior and capacity in the beet armyworm, Spodoptera exigua (Hübner) were investigated under laboratory conditions (27℃ ±1℃, L14∶D10). The results indicated that both males and females were able to mate on the first night, and all males and females observed completed their mating on the second night after emergence. The mating rates on the first three nights were relatively high (>82%), and decreased significantly after the fourth night (<50%). Daily mating activity occurred from 23:15 to 05:30, and peaked from 01:30 to 02:30 and from 03:00 to 04:00, with a higher frequency in the first peak. Mating duration of the moths lasted from 30 to 60 minutes (40.8%, n=97), followed by 60 to 90 minutes (19.4%), and in some cases (10.2%) lasted more than 180 minutes. Furthermore, mating durations were highly associated with the moth age: in the older moths it lasted significantly longer than in the younger ones. Lifetime mating number for a male was from 1 to 11, with an average of 50 However, mating capacity of a male was significantly associated with operational sex ratio. The lifetime mating number of males was only 3.0 in average when a male was confined with one female, but increased to 5.1-6.0 when a male was confined with 2-5 females. On the other hand, the percentage and frequency of female mated were also tied to sex ratio. This could be demonstrated by the fact that the percentage of unmated female increased from 8.3% to 32%, and oncemated females from 16.7% to 38.7%, at a sex ratio of 1:1 and 1♂:5♀, respectively, whereas the proportion of females that mated more than 5 times decreased from 25% to 0 under the same conditions. The significance of these findings for the application of sex pheromones to control the beet armyworm was discussed.

The effects of environmental factors such as photoperiod temperature and food quality on the incidence of diapause in the hawthorn spider mite, Tetranychus viennensis Zacher were investigated. The results show that the critical photoperiod for inducton of diapause was 12 hours and 32 minutes. The stages from larva to the protonymph, or from protonymph to the deutonymph, were more sensitive to photoperiod than other stages, however, among these a single developmental stage could not induce diapause. Feeding on the same host plants, the diapause incidence on old, diseased and young leaves were 69.7%, 55.3% and 20% respectively. Short photophase and low temperature (15℃, 18℃, 21℃) enhanced the incidence of diapause (100%, 93.1% and 66.7% respectively). Higher temperature (24℃) inhibited diapause,and diapause did not occur at 27℃.

Opius caricivorae Fischer is a major lavalpupal endoparasitoid of Liriomyza sativae Blandchard. The adult biology of this parasitoid was investigated under laboratory conditions using L. sativae on the bean Phaseolus vulgaris L.as the host. The adults emerged by daylight, with the peak emergence at 8:00-10:00, and 91% of them mated on the day of emergence. Femalebiased adult sex ratio were found in laboratory populations (♀∶♂=1.51∶1). Longevity of both female and male adults decreased with the increase of temperatures from 17℃ to 33℃ when honeybee solution was provided. Mean longevity of females was longer (81 d at 17℃ and 14 d at 33℃) than that of males (47 d at 17℃ and 13 d at 33℃). Female adults started oviposition on 1-2 d with the peak occurring on 2-7 d after emergence at temperatures from 21℃ to 29℃.The relationship between average fecundity and temperature could be fitted to the equation　=-0.057x^{2+2.728x- 20.601 (r2=0.934). The females were able to kill hosts by stings. Feeding,oviposition and ost-searching behaviors of the parasitoids are also described.}

This paper describes the comparative morphology of the three subspecies of Gastrolina depressa Blay: G. depressa depressa Baly, G. depressa pallipes Chen and G. depressa thoracica Baly. Comparison of the morphology, biology and zoogeography, of these subspecies indicate that they should be restored or elevated to species rank: Gastrolina depressa Blay, G. thoracica Baly, and G. Pallipes Chen, stat. Nov. This is based on the following observations: 1) the morphology of labrum, labium, hindwing and claws without distinct differences, however, antenna, mandible, maxillary and spermatheca with distinct differences. From the microscopic morphological comparison, the three subspecies are all with distinct differences. 2) The distribution of G. depressa depressa Baly and G. depressa thoracica Baly is overlapping between 25°-30°N in China, but can be differentiated by altitude in some areas. On the other hand, G. depressa pallipes Chen is mainly distributed in Yunnan Province and does not overlap with the other two species in distribution.

Three new species of Culidae from Yunnan are described and compared with related species. Uranotaenia (Pseudoficaerbia) qui Dong, Dong et Zhou, sp. Nov. is very similar to Ur. Novobscura and Ur. Bimaculata. Holotype 1 male; paratypes, 1 male, 2 larvae and 2 larvae skins; all collected in Jinhong County, Yunnan (Dong, Ⅸ. 1997; elevation 780 m). Heizmannia (Heizmannia) menglianeroides Dong, Dong et Zhou, sp. Nov. is related to Hz. Menglianensis Lu et Gong 1996. Holotype 1 male; paratypes 3 males, 4 females, 2 larva,4 larva skins, 4 pupa skins; all collected from bamboo holes in Jiluoshong, Xishuangbanna, Yunnan (Dong, IX. 1996; elevation 680 m). Culex (Thaiomyia) cheni Dong, Wang et Lu, sp. Nov. is very close to Culex (Thaiomyia) hainaensis Chen, 1977. Holotype 1 female; paratypes 14 males, 22 females, 8 larvae; all collected from bamboo holes in Tenchong County, Yunnan (Dong, Ⅶ. 1986; elevation 1 795 m). All types are deposited in the Institute of Malaria Prevention and Treatment of Yunnan Province except six paratypes (2 males, 2 females and 2 larvae) of Cu. (Th.) cheni Dong, Wang et Lu, sp. Nov., which are deposited in Guiyang Medical College.

The induction of plant proteinase inhibitor (PPI ) by insects has been the subject of considerable research interest. After being attacked by insects some plants can release proteinase inhibitor inducing factor (PIIF) at the site of injury. PIIF stimulates the production of systemin which activates the synthesis of jasmonic acid through the octadecanoid pathway. Jasmonic acid activates the PPI gene causing new PPI to be synthesized. On the other hand, insects can develop adaptations to PPI through the following mechanisms: （1） changing the sensitivity of the insect proteinase to PPI; （2）decomposing PPIs; （3） feeding excessively and interfering with the PPI production signal pathway. The signal molecules and their functions in inducing PPI production and the adaptation to PPI by insects are reviewed.

The 3′terminal of the actin genes in the brown planthopper, Nilaparvata lugens (Stal) was amplified, cloned and sequenced using the anchored 3′RACE method. Through homologous comparison of these sequences in untranslated regions, we found that BPH-A and BPH-D were different from other sequences, and that BPH-B, BPH-C and BPH-E had the same sequence except for different 3′ terminal sites. The amino acid sequence of the 3′ terminal of the actin genes in N. lugens is highly conservative. According to structural characteristics of the actin genes, we conclude that BPH-A and BPH-D are muscle specific while BPH-B, BPH-C and BPH-E are cytoplasm specific.