Insect cold hardening processing is related with the activity of some enzymes of intermediary metabolism, including enzymes of glycolysis, hexose monophosphate shunt and cryoprotectant synthesis. In this study, overwintering larvae of pine needle gall midge, Thecodiplosis japonensis, were sampled at various dates over 1998～1999 winter and the profile of enzymic activity of intermediary metabolism was studied. The increased glycogen phosphorylase during overwintering ensured the required flow of carbon into the synthesis of trehalose. Enzymes of glycolysis (hexokinase, lactate dehydrogenase, aldolase) showed low activities during overwintering when more carbon flowing into trehalose synthesis. The glucose-6-phosphate dehydrogenase increased during overwintering, indicating that reduced condition of cell might keep the cell in proper function even in cold temperature, and also for cryoprotectant synthesis. The changes in trehalase activity showed that low activity was for keeping higher trehalose content and high activity for removing it in the spring.

The chitinase gene of Helicoverpa armigera single enveloped nucleocapsid nucleopolyhedrovirus (HaSNPV) was amplified by using PCR method. The nucleotide sequence of the coding region was determined. The total length of the coding region was 1.713 bp and was potential to encode a 570 amino acid polypeptide with predicted molecular weight of 636 kD. The alignment of HaSNPV chitinase amino acid sequence with those of other 7 reported baculovirus chitinases showed that HaSNPV chitinase was most closely related to HzSNPV chitinase, with 90.7% amino acid identity. It also shared a high degree of homology with chitinases of AcMNPV, BmNPV, HcNPV, LdMNPV, OpMNPV and CfMNPV, with 64.4%, 64.9%、64.2%、62.9%、66.2% and 61.5% amino acid identity, respectively. A phylogenetic tree of 8 baculovirus chitinases was drawn by using PC＼GENE program, and compared with the phylogenetic tree based on the polyhedrin amino acid sequences of the same 8 baculoviruses. The result showed that the evolutionary rate of chitinase genes was in some degree different to that of polyhedrin genes.

Homing behaviour in the ant, Tetramorium caespitum, with food was quantitatively studied. We demonstrate that after obtaining food the ant workers are able to rapidly return to their nest along a new, ‘beeline’ route and are not bound to retrace their outward tortuous routes during foraging. The sun and polarized skylight pattern can be used as a cue for homing, and a nonpolarized lighting can guide the ant home directly as well. The results suggest that T. caespitum with an advanced social structure uses the brain to navigate by the light.

he effect of pyrethroid insecticide deltamethrin on mesencephalic originated dopaminergic cell line MN9D was investigated by using the patchclamp and Fura-2 microfluorimetric techniques.Whole cell calcium current recordings showed: deltamethrin activated calcium channels (H-VOCs) and increased the amplitude of calcium currents greatly by about 20.64% in 1 min and 15.48% in 5 min at very low concentration (10^-9 mol/L).Deltamethrin could increase the ［Ca²⁺］I in both normal and calciumfree bath solutions. This indicates deltamethrin could stimulate the calcium store to release the cytosolic free Ca²⁺. We conclude deltamethrin stimulates ［Ca²⁺］I entry through the calcium channels and release of Ca²⁺ from intracellular store. Prolonged elevation of ［Ca²⁺］I will affect many cellular process and cause cytotoxic to the cells.

The genetics of resistance to avermectins (AVMs) and the relative fitness between resistant and susceptible strains to AVMs in diamondback moth (DBM), Plutella xylostella, were investigated during 1997～1999. The methods of cross and backcross between AVMsselected resistance strain and isogenic susceptible strain were used for exploring the inheritance mode of resistance to AVMs in DBM. The results showed that the degree of dominance of FRS and FSR were -0.64 and -052, respectively. It suggested that the resistance of DBM to AVMs was autosomal, incompletely recessive and probably polygenic confirmed by χ² test. The activities of acetylcholinesterase, carboxylesterase and glutathione S-transferases of F₁ hybrids were lower than that of resistance parental strain, and continuously declined in F₂ and BC. The resistant strain possessed 0.84 of fitness value relative to the isogenic susceptible strain.

Eleven new synthetic polyacetylenes were screened for their biological activity to the 4th instar larvae of the mosquito Culex quinquefasciatus. The toxicities of some compounds to the tested insects were found to be enhanced greatly by irradiation with near-UV. Compound 5 (1-phenyl4(3,4methylenedioxy)phenyl-diacetylene) is an effective photosensitizer,of which LC_{50+UV-A (in the presence of UV-A) and LC50-UV-A(in the absence of UV-A) to the larvae were 0.35 μg/mL and 8.89 μg/mL respectively.The ratio of photoactivity ［(LC50-UV-A)/(LC50+UV-A)］ was 25.65. The results in simulated field experiment showed the phototoxicity of compound 5 also was enhanced greatly to the tested larvae by sunlight. The mortality of presence and absence of sunlight were 81.63 and 11.40 percent respectively. The result of preliminary experiment by adding different kinds of antioxidants showed the compound 5 belongs to the type of yielding superoxygen radical in organism and it differs from α-terthienyl (α-T) in the mechanism of photodynamic action. The analysis of structure-bioactivity shows that diacetylene of biphenyl-containing derivatives has higher activity in photoxicity than diacetylene of bialkyl substitute. Different substitutes on phenyl also affect its effect,the order in activity is methylene dioxy>methoxy>o-nitro>m-nitro>methyl ester.}

Fluoridetolerant mechanism of silkworm larvae,Bombyx mori was studied by cytochemical method at ultrastructural level associated with excessive ingestion of fluoride. Results showed that excessive ingestion of fluoride could inhibit the acid phosphatase (ACPase) activity both in blood and midgut tissues of silkworm larvae and ACPase activities was decreased as the fluorine content in the mulberry leaves increased. However, ACPase activity in the blood exhibited a sudden rise when the content of fluorine in the food reached a certain level,but that in the midgut tissues kept dropping. It was demonstrated in the present study that this turning point of ACPase activity in the blood was related with the fluoride-tolerance of silkworm varieties,and the increase of ACPase activity in the blood was caused by the release of ACPase from the destroyed midgut tissues, owing to the poison effect by high fluoride content ingested. It is believed that the different effects of fluoride on the ACPase activity in different silkworm varieties reveal the mechanism of fluoride-tolerant ability of silkworm larvae.

The shape of newly laid eggs of the wasps Microplitis mediator is different from that of the eggs in the calyx region, due to mechanical press while they pass through the ovipositors, which initiates the development of the embryos. Six hours after oviposition, the embryo attains the germ band stage, and a serosal membrane is observed. Hatching occurs at 32～34 h. Immediately after hatching, the cells from the upper serosal membrane of the embryo disperse to form teratocytes in the haemocoele of the host, while those from the lower part are released gradually. The 1st instar larva has a pair of sclerotized mandibles, which are used as a weapon to fight with its conspecies competitors. A caudal sac is well developed after the larva enters its 2nd instar at 108～113 h.The surface of a mature teratocyte (6 days after parasitization) is covered with numerous microvilli. A vesiculated endoplasmic reticulum system disperses throughout the cytoplasm in which many Golgi complexes exist too. The nucleus is extensively ramified.

In this report, a preliminary isolation of AS from the brains of larvae, Mythimna separata, is described. The ASactivity material which can inhibit JH synthesis by CA occurs in the brains of last instar. The ability of brain extract to inhibit JH synthesis in vitro was tested by radiochemical assay. Using 1 brain equivalent, 51% inhibition of JH synthesis was achieved. If the brain extract was pretreated with trypsin, the inhibitory effect of the extract was greatly reduced. Assays of fractions from the reversalphase C18 column of HPLC separation showed that materials with AS activity were eluted between 5.2% to 28% methanol (fraction 1～20), and between 40% to 76% methanol (fraction 30～60). Assays of fractions 3, 5, 11, 40, 54 and 60 using 5 brain equivalents per pair of CA showed >50% inhibition of JH synthesis. Further purification of the fractions from the C18 column with allatostatic activity is in progress.

Effects of infestation of the pine caterpillar,Dendrolimus puncatus and needle-cutting on the chemical components in the needles of Pinus massoniana were investigated for 10 days after treatment.Higher tannin content and lower contents of phenols and soluble sugars were found in the needles of the pine infested by the caterpillar than injured by needle-cutting,but the differences did not reach the significant level,indicating no obvious differences of these components during that term in response to the two injurious manners.The changes of nutritional material (soluble sugars) and secondary metabolites (tannin and phenols) in the needles of P.massoniana injured by infestation of the pine caterpillar or needle-cutting and in the needles of control pine were monitored for three successive years.It showed that contents of the secondary metabolites in the needles of the pine damaged by the two manners fluctuated along with time.They decreased in the first year after treatment and then went up to the normal level.Protein content in the needles of treatment pines was always higher than that in the control.Therefore,the induced chemical changes in the needles usually lag behind.

Feeding behavior of the cabbage aphid ( Brevicoryne brassicae) was recorded with electrical penetration graph (EPG) and glucosinolates in tissues of mustard (Sinapis alba ) parts were analyzed with HPLC to investigate the roles of glucosinolates in the host plant part preference by the aphid. Three plant parts of mustard were chosen for EPG recording and chemical analysis, I.e., the laminas and petioles of the 7th fully expanded leaves, and stems of flower buds. Stylets of the aphids on the stems could reach the phloem with less probes and shorter time compared to those of aphids on other two parts. And no significant differences were found in feeding behaviors among aphids on three plant parts once sustained ingestion started in the phloem. Only sinalbin of three glucosinolates was found from epidermis and cortex in the stems of flower buds. Our results indicate that sinalbin is an important indicative chemical or feeding stimulant in host plant part preference by the cabbage aphid.

This paper deals with a new record genus and a new species from Gansu Province, China: Swirskiaphis Hille Ris Lambers, 1966 and Swirskiaphis bambuciepula Gx Zhang et Zhang, sp. Nov.. All the type specimens are deposited in the Institute of Zoology, the Chinese Academy of Sciences.

The phylogenetic relationships of 9 superfamilies of Hydrachnellae (=Hydrachnidia)were studied.The cladistic analyses were made using 23 morphological characters and 3 biological characters.A classification scheme,based on the phylogenetic relationships within Hydrachnellae,is proposed for 5 groups with 9 superfamilies.Pseudohydrachnidia is the most primitive group containing one superfamily (Stygothrombioidea);Protohydrachnidia contains one superfamily(Hydrovolzioidea);Euhydrachnidia consists of 2 groups Achihydrachnidia and Neohydrachnidia;the Achihydrachnidia contains three superfamilies(Hydrachnoidea,Hydraphantoidea,Eylaoidea)and Neohydrachnidia four superfamilies(Sperchontoidea,Lebertioidea,Hygrobatoidea,Arrenuroidea).Following sister groups are suggested:Pseudohydrachnidia and Protohydrachnidia+Euhydrachnidia;Protohydrachnidia and Euhydrachnidia(Achihydrachnidia+Neohydrachnidia);Achihydrachnidia and Neohydrachnidia.Comparisons with hypotheses by other authors are given.

Progress achieved in the past two decades is reviewed in terms of following 5 aspects:①endocrine regulation of reproduction and development,②sensory functions and behavioral specialization,③dispersal and migration,④mechanism of insecticide resistance,and ⑤insect immunity.Reproductive diapause in 3 species of lady beetles due to deficiency in feeding on artificial diets,was partly mended by adding JH analogue ZR512 into the diets,which would promote vilellogenesis and ovary development.In eri silkworm it was found that both PTTH from the brain and ecdysone secreted by prothoracic glands were indispensable for normal development of the ovaries in pupal stage.In Bombyx mori,it was revealed that addition of phytogenous ecdysone into the food would promote RNA synthesis in the silk gland.The induction of trimolters by applying imidazole compounds such as KK-42 to the 3_rd instar larvae of tetramolters,was investigated in the light of the altered action between corpora allata and PTTH secretion in the brain.Delay of MH peak and deficiency of JH were regarded as the cause resulting in trimolter formation.Progress in the studies on sensory function of chemical and visual receptors was achieved in the application of sex pheromones and plant secondary substances for pest control and to unveil the effect of periodic light change on behavioral response.Dispersal capacity of natural enemies of pest insects was studied for biological control,and migration of some mobile insects such as the moths of armyworm and rice leaf roller was studied to reveal the cause of their seasonal occurrence and damages to crops in different regions of the country.The resistance of some medical and agricultural insects to organic phosphorus and pyrethroid insecticides related to gene amplification and changes in sensitivity of the neural target sites to the insecticides,has been investigated and confirmatory results have been obtained.Due attention has been paid to insect immunity in relation to their organic adaptation to harsh environmental elements.

The studies on biological control of insect pests and its applications in southern China since 1949 were reviewed in this paper. Mass production of Trichogramma spp. With eggs of Philosamia cynthia ricini Boisd to control sugarcane borers has made great success since 1950s, and contributed a valuable experience for the mass production of parasitoids later with Antheraea pernyi eggs. Releasing Anastatus sp. For controling of Tessaratoma papilosa Drury has significantly relieved the damage of pests in Lichee production. Introduction of natural enemies such as Rodolia cardinalis Muls., Cryptolaemus montrouzieri Muls., and Coccobius azumai Tachikawa to control Icerya purchasi, Pseudococcus sp., and Hemiberlesa pitysophila respectively are well known as successful examples of biological control in China. The control of citrus insect pests with Oecophylla smaragdina, the earlist biological control practice in China, has been developed and expanded in citrus orchards. The integrated control of rice insect pests has been carried out in the Dasha Township of Sihui County, Guangdong Province for 26 years since 1973, and made great achievements both in theory and practice. The fundamental and applied researches of insect pathogens, including the control of mosquito with B.t.I., discovery and application of DpCPV, isolation and production of SlNPV, and mass reproduction and application of nematodes, have made significant contributions in fighting against agricultural insect pests. Raising toxicity level and expanding insect killing spectrum of pathogens through gene recombinant has also made significant progress.