The effects of methomyl on the synaptic transmission of the 6th abdominal ganglion of cockroach (Periplaneta americana ) were studied. The ganglions were partially desheathed and immersed in variousconcentrations of methomyl solution. By stimulation of the bilateral cercal nerves Xl at a rate of 1Hz/sec, evoked excitatory post-synaptic potential (EPSP) and post-synaptic action potential were recorded withmannitol gap method. With weak stimulation only EPSP could be recorded, and under the action of 100 μmol/L methomyl, an increase in the amplitude and duration of the EPSP was first observed, and thenpostsynaptic action potential could be evoked; however, afterwards the amplitude of EPSP reduced progressively until finally disappeared, but the pre-synaptic response remained unchanged. The EPSP could berestored by washing cockroach with saline. With strong stimulation, the post-synaptic action potentials, uperimposed on EPSP, could be recorded. Under the action of methomyl solutions, the synaptic transmission was blocked. The blocking action of methomyl was reversible by washing, however, it still remained some post-effect after 30 min washout. The LD50 for methomyl to adult male cockroach was (3.56+0.01) μg per gram body weight determined by abdominal injection. Based on the action of methomyl on ACHE, the basic characteristics of the blocking process and its killing effect to the insect were discussed.

The bioassay data showed that the Asian corn borer ( Ostrinia furnacalis G. ) was unable to grow and develop on diet without sterols . When cholesterol or sitosterol was added to the diet withoutsterols, the larvae could normally grow and develop. They could also grow and develop on the stigmasterol diet, but the average body weight of 9-day larvae and pupation ratio were lower than that of the control and the cholesterol and sitosterol diet groups. The △⁷-lathosterol in diet was difficult to be metabolized in this species. After extraction and purification, the samples of sterols were analyzed by capillary GC. The results indicated that the quantity of cholesterol in 5th instar larvae of Asian corn borer fed on sitosterol diet was similar to that of the ones fed on normal diet, however the quantity of cholesterol in 5th instar larvae fed on stigmasterol diet was much lower. The results suggest that in Asian corn borer △⁵-plant sterols-sitosterol and stigmasterol could be converted to cholesterol by dealkylation at C₂₄ Of the side chain. But there exists metabolic difference between sitosterol and stigmasterol.

This paper deals with the effect of mutation on the Bornbyx rnori nuclear polyhedrosis virus (BmNPV) induced by mitomycin C (MMC) and dimethyl sulfoxide (DMSO) in the pupa of the silkworm. MMC is a mutagenic substance to BmNPV: (1) There was significant dosage effect upon the delay of infective period and the decrease of pupal mortality; (2) Morphological changes of the polyhedra were observed in some diseased pupae and their hereditary stability was testified in the next generation. Some polyhedra with extraordinary large size (15.0- 30.0 μm) having diagonal fission on the square surface were observed for the first time; (3) Structural changes were found within the mutated polyhedra and (4) The mutated BmNPV-DNA were digested by EcoRI, Bgl II and Bam HI, their electrotpherogram depicted the occurrence of some additional bands and the absence of other bands. These results show that MMC could induce the genome of BmNPV to mutate at many loci. DMSO does not induce mutagenesis in BmNPV with dosage below 9.0 μL/pupae.

SDS-PAGE analyses of the proteins of midgut, hemolymph and fat body indicated that the infection of HaNPV may stimulate initially and then inhibit the synthesis of the host proteins. During all the infected courses, no polyhedrin was found in SDS-PAGE pattern of the midgut and hemolymph. On the contrary, the polyhedrin band appeared in the fat body cells, at both 96 hr and 120 hr after oral inoculation, suggesting high expression of the polyhedrin in the fat body cells. Electron microscopical observation showed that: Oafter oral inoculation, the virions as well as the budded virus produced via replication in the midgut could enter into hemocoel and then infect fat body, On the other hand, the midgut could also be infected by the virions from hemocoel injection. In other words, the midgut is not only a primary infection origin, but also a tissue susceptible to secondary infection; (2) There was a structural barrier between the midgut and the hemocoel.

A series of laboratory experiments were carried out to test the biological activities of Aver mectins against the vegetable leafminer Liriomyza sativae Blanchard. The results showed that the LC₅₀ of Jieyangmygin for the first, 2nd and 3rd instar larvae were 1.54 ×10^-4 g/L, 3.73×10^-4 g/L and 1.99×10^-3g/L, and that for Abamectin were 1.48×10^-4 g/L, 3.68×10^-4 g/L and 1.97×10^-3g/L, respestively. The first instar larvae of L. sativae was the most sensitive to Avermectins in the three instars, the LC₅₀ of Jieyangmygin against the 3rd instar larvae was 12.9 times that of the first instar larvae. For fe male adult, the LC₅₀ at 24 h, 48 h by residue bioassay to Jieyangmygin were 3.12×10^-3 g/L and 2.08×10^-3 g/L. Feeding and fecundity of adults were inhibited by Jieyangmygin for 4-8 d and 10 d, respestively. When the larva were exposed to the leaves which had been treated with 0.005 g/L Jieyangmygin, their survival rates within 6 d, 8 d and 10 d were 0, 16.13% and 28.07%, respectively. The results from field trials indicated that the population density of leafminer reduced by 91.1% and 90.9 % after treated with 0.005 g/L Jieyangmygin and 0.0045 g/L Abamectin in 6 d and there is not significantly different between them (P >0.05 DMRT). The results also showed that the population density of the leafminer reduced by 93.6% after treated with 0.0067 g/L Jieyangmygin in 6 d.

This paper deals with the natural dynamics of Eriococcus lagerostroemiae Kuwana popu lation. This insect pest spread into Guiyang, Guizhou Province, in the late 1980s and occurred3-4 generations during a year. A mixture of the third and fourth generations overwintered. Itcould survive the winter in egg, nymph and pupa. The threshold temperature of development (T₀) was estimated to be -0.3℃ for egg, 17.5℃ for male nymph, 14.2℃ for pupa, 18.8℃ for female nymph and 10.2 C for female adult, with effective temperature summations (K) of 540.8, 88.4, 73.0, 98.0 and 79.1 day-degree, respectively. There were two peaks in population fluctuation each year, which appeared at midde June to early July and early August to early September. The population density gradually decreased from November to early April as the host plant, Largerstroemia indica L., entered dormant stage and the temperature got lower. The fecundity of the female adult depended on the growth state of the host, the better the tree grew, the more the egg was laid. The lady beetle, Chilocorus kuwanae Silverstri, was the most effective natural enemy controlling the pest. A better chemical control method is to smear pesticide on the tree truck, branches and twigs and watering with systemic insecticide as a supplementary means.

Characteristics and dynamics of arthropod communities were investigated in three experimental plots of cotton, the plot where the transgenic Bt cotton R93-6 was planted and integrated pest management was carried out (IPM), the plot of the Bt cotton in which pests were controlled only by their natural enemies (NEC), and the control plot of routine cotton CCRI No. 16 with no insecticide application throughout whole growing seasons (CK). The results showed that the diversity indexes and evennesses of insect community, pest and natural enemy sub-communities were lower in NEC than in CK, while their dominant concentrations were higher than that in CK. So the insect community, pest and natural enemy subcommunities had poorer stability in NEC than in CK, suggesting some species of pests might go into outbreak. The insect community and pest sub-community in IPM were more stable as compared with those inNEC and CK. The analyses on seasonal change in the insect community in NEC showed it could be divided into three stages. The first stage was from early June to late July, the second one from the end of July to the end of August, and the third one after September. The corresponding management strategies against the insect pests were put forward according to occurring characteristics of insect pests and their natural enemies during these three stages.

This paper deals with the growth, survival, fecundity and reproductive isolation of four Oligonychus ununguis (Jacobi) populations from different forest regions on conifer and broadleaf trees. Rearing experiments showed that the population on the conifer Cunninghamia lanceolata failed to completeits life history when raised on the broadleaf trees Castanea mollissima and Ouercus acutissima. And all individuals of the populations from broadleaf trees died at nymphal stage when reared on conifers such as C. Lanceolata, Pinus thunbergii and P. Firma etc. Reciprocal cross tests between the populations showed that the adults originated from the population on the conifer and those from populations on the broadleaf trees did mate, but the females either did not oviposit at all or laid unfertilized eggs which only produced male nymphs, indicating the existence of reproductive isolation. These results suggest that the Oligonychus ununguis populations on conifer and broadleaf trees might consist of two different species, but not one common species as usually considered.

An investigation on the body fleas and burrow nest fleas of Meriones unguiculatus in Etuokeqian Banner of Yikezhao League, Inner Mongolia Autonomous Region during 1982-1996 was summarized asfollows: There were fifteen flea species on the gerbil's body with Xenopsylla conformis conformis (50.8%) as the dominant one and Nosopsyllus laveiceps kuzenkovi (40.6%) coming second. There were fifteen flea species in the gerbil's burrow nest with N. l. kuzenkovi (74.3 % ) as the dominant species and the common species being Neopsylla galea ( 11.9 % ) and Coptopsyllus lamellifer ardua (8.1% ). Theindex of the yearly burrow nest flea averaged 6.92 times that of the body flea. No correlation was found between the fleas of body and burrow nest (P>0.05), and between their infection rates (P>0.05). Both the diversity and evenness of body and burrow nest fleas were stable relatively in different years. As the burrow nest flea index of N. I. Kuzenkovi in spring or autumn reached above ten in two successive years, the animal plague might occur.

This paper deals with 60 species of Cleoninae belonging to 2 tribes 23 genera collectedfrom Xinjiang Uygur Autonomous Region, of which 24 species are newly recorded from China. The faunal compositions include the Central Asian, Europe-Siberia, Centrical Centro-Asian, Palaearctic and endemic ingredients, of which about 53% (31 species ) belong to the Central Asian ingredients. The Cleoninae has important economic value, of which 9 species belong to injurious insects of desert forest and 30 species belong to injurious insects of beet. Especially, Bothynoderes punctiventis (Germ.) and B. libitinarius Faust are major pests of beet in Xingjiang.

A new species of Kangacris Yin , K. Keshanensis sp. Nov. is described. The type specimen is deposited in the Department of Biology, Northeast Normal University.

This paper deals with one new species of the genus Sophonia from Guizhou Province, S. Spathulata sp. Nov.. The type specimens are deposited in Guizhou University.

A comparative anatomical study of male genitalia of species of philid beeles was performed. The characteristics of male genitalia were confirmed to be valuable for the classification of philid beeles. Besidesthe structure of the median lobe and the lateral lobe, the difference in the shape of the armature of the internal sac which shows a high degree of stability was proved to be a valuable character in separating generaand species. The characteristics of male genitalia of 3 genera, 6 species including a new species, Philusantennatus (Gyllenhal), Philus pallescens Bates, Mantitheus pekinensis Fairmaire, Mantitheus gracilis Pic, Mantitheus taiguensis sp. Nov. and Heterophilus punctulatus Chiang, Chen et Zhang were described. According to the characters of the male genitalia, a phylogenetic tree of these genera is advanced.

This paper is a systematic review and analysis of the morphology and classification of subspeciesof the Doratopsylla coreana Darskaya, 1949. Results indicated that: (1) There is a great variation in theratio between the length and middle width of clasper of the known subspecies of D. coreana Darskaya,1949. These variations are often related to specimen preparation; usually there is significant differencewhen they were completely flattened or not. Therefore there is certain disadvantage simply using the ratioas an index for species classification; (2) Usually the movable process and immovable process are treated as "hard structure", while for "soft structure" such as crochet of aedeagus and duct of spermatheca, whenthey are pressed during specimen preparation their direction and form may develop difference or deviation. Since 1970s form of the crochet of aedeagus has played an important supplementary role in the identificationof flea species and subspecies. But there must be a prerequisite that it really shows the actual difference between the movable process and immovable process of the male flea. Furthermore, the filling status of digestive tract, the pressing direction of the body and other factors may also cause errors in classification; (3)Based on the discriptions of the eleven published papers and the comparison of the figures in them as well asexamining the specimens collected by authors ourselves, it is found that there is no difference between themorphology of D. Coreana coreana Darskaya, 1949 and D. Coreana sichuanensis Wei, Chen et Liu,1981. Moreover, there is no essential difference between the morphology of D. coreana araea Smit et Rosicky, 1976 and D. jii Xie et Tian, 1991. The same number of the subspecies of Doratopsylla coreana Darskaya, 1949 keeps, i.e, D. coreana coreana (= D. coreana sichuanensis ); D. coreana waissemani; D. coreana araea (=D. jii ); D. coreana jianchuanensis; D. coreana hubeiensis; D. coreanaliui (=D. liui). Key to the six subspecies is given.

Two new species, Pachylaelaps nuditectus sp. Nov. And Pachyseius chenpengi sp. Nov. Of the family Pachylaelaptidae are described from Heilongjiang, China.

Therm hysteresis found at first in insects, is one of the basic characteristics of antifreeze proteins (AFPs). Comparing with fish and plant AFPs, the insect AFPs has higher therm hysteresis activityand unique chemical structure features. It plays an important role in the physiological antifreeze course ofinsects, as follows: 1) inhibiting the growth of ice crystals; 2) increasing freeze-tolerance; 3) possiblycontributing to water balance of insects. Photoperiod, temperature and humidity are the external factorsthat regulate the metabolism of AFPs; and the changes of hormone in the body may be the direct internalcauses that control the AFPs' synthesis in the fat body.