The rotation and mixture treatments of pesticides are two main strategies of pesticide application in the management of pest resistance to pesticides.The comparison of influences of the rotation and mixture treatments on the resistance evolution and the best interval period for rotation treatment of two pesticides were studied using resistance models and experiments in diamondback moth,Plutella xylostella, a “synthetic population” with 0.01 initial frequency of resistant individuals in laboratory. The simulating results on the computer indicated that the effect of rotation and mixture treatments on the resistance evolution was mainly depended on the intensity of action of pesticides,the fitness value of resistant genotype individuals and the mode of action of the mixture of the two pesticides.As for delaying the resistance evolution,the best effect could be gained under any circumstance if two pesticides were applied alternatively at every two applications. After treatments of 8 generations,the bioassay results indicated that the resistance ratio of the 3rd instar larvae to fenvalerate by the leaf dip method was 75.87 for successive treatment with fenvalerate, 28.67 for rotation treatment of fenvalerate and methylpo and 58.72 for mixture treatment of fenvalerate and methylpo.These data showed that the results from the simulation of system models had a good consistency with the bioassay results from the experimental population of the diamondback moth. It suggested that this system could be used to predict the resistance development and evaluate the resistance management strategies of pest population.

CO-difference spectrum of midgut microsome preparation with P450 content of (687±11) pmol/mgPr. Showed absorbance peak at 450nm. O-demethylase of pnitroanisile(pNA) was maximally active at pH 7.8 and temperature 20～25℃. Activity was linear with respect to time for up to 30min, and with respect to enzyme level for up to 5 tissue equivalents/ incubation with 750 g supernatant as enzyme source. Km and Vmax of O-demethylation of pNA estimated were 1.23 mmol/L and 2.54nmol p-nitrophenol formed/mgPr/min. respectively. NADPH was one of the requirements for the O-demethylation of pNA, the activity without external NADPH is 16% as that of with 0.25mmol/L NADPH. 1.5% BSA added in the incubation mixture enhanced (1.2 folds) the production of p-nitrophenol. PBO (1 mmol/L) strikingly (90%) inhibited O-demethylation.1.73 folds induction of O-[demethylase activity was observed by dietary 0.25% PB.

As a juvenile hormone analog (JHA), pyriproxyfen has showed a very high efficacy in cockroach control. The effects of JHAs on vitellogenesis and reproduction in many insects have been widely reported. In this study, the effect of pyriproxyfen on the vitellogenesis and reproduction of Blattella germanica has been investigated by employing immunological and biochemical methods. When the female adults were treated with pyriproxyfen, the synthesis of vitellogenin in fat body was promoted, and the biomodel of vitellogenin in haemolymph exhibited a very different pattern, i.e. 2 peaks of vitellogenin content. Vt began to accumulate earlier and maintained at a very high level for several days, then decreased quickly afterward in the ovary of treated female. At the 9th day the Vt content lowered to half of the peak level in the normal adult of the same day-age. When the newly emerged female adults were treated with this JHA, they became sterilized.

Change patterns of feeding and midgut protease activities of larval Helicoverpa armigera during the fourth instar were investigated. It was shown that food amount eaten by the larvae and body weight gain of the larvae were low at the beginning and the end of instar and peaked at the middle of the instar. Activities of trypsin-like enzyme, chymotrypsin-like enzyme and total proteolysis showed concurrent change patterns with the feeding amount during the 4th instar. Larval ingestion exhibited continuous-feeding pattern, and feeding actions took about one sixth of the total time.

The regression method was adopted to establish mathematical models for the selection of most effective combination of pH value of buffer, constant temperature, reaction time and substrate concentration, that are four major factors affecting activity of phosphatase, either acidic or alkaline, in Tetranychus cinnabarinus. The models are: Y_acidic=0.456380+0.107889X²+0.069027X³-0.026836X₁²-0.030794X₃², F=24.98，P<0.01; Y_alkaline=0.267286-0.200736X₁+0.049541X₂+0.030930X₃-0.049063X₁X₂+0.053585X₁²-0.049665X₂², F=57.68, P<0.01. It reveals that the acid phosphatase has the highest activity under the combination of buffer pH 4.4, temperature 42℃, reaction time 42 minutes and substrate concentration 8.5×10^-3 mol/L. The reaction time is a key factor affecting acid phosphatase. The key factor affecting alkaline phosphatase is the buffer pH. The best combination is pH 9.0, 37℃, 30 minutes and 7.5×10^-3 mol/L.

RAPD-PCR was used to detect the population differentiation of green peach aphid, Myzus persicae (Sulzer) on tobacco from different regions in China, and the results showed that the use of different primers in the RAPD method permits detection of different levels of DNA polymorphism in the aphid's population. Nei's genetic distance (D) shows that the differentiation of the aphid from tobacco is only at population level instead of subspecies or species level. Three primers screened from nineteen were used for cluster analysis based on similarity index (SI) and Nei's genetic distance (D). Although there exist some differences between the cluster results of SI and D, they both can show the DNA differences of geographic populations and color forms of the aphid. At DNA level, compared with the holocyclic aphids (from northern China), the aphids mixed with holocyclic and anholocyclic life cycles (from central China) are more similar to the anholocyclic aphids (from southern China), but there is no obvious difference among the aphids from central China. The results also show that, compared with yellowish green forms, the red forms are more similar to the brown ones of the aphid.

The ultrastructures of male external genitalias of Luehdorfia species were observed with scanning electron microscope. For these four Luehdorfia species, i.e. L. chinensis Leech, L. longicaudata Lee, L. puziloi Erschoff and L. japonica Leech, the appearances of whole male external genitalias are similar, and their ultrastructures of harpago, uncus, aedeagus and juxta are markedly different. These ultrastructural characters could be used for identifying the species of Luehdorfia. According to the results from comparing the differences in morphological structures of male external genitalias and clustering analysis of the parameters about male external gentalias of these butterflies, the relationship among these four Luehdorfia species is discussed. It is suggested that L. chinensis with the most primitive structure of male external genitalia has a near relation with L. longicaudata and perhaps is the nearest to the ancestor of Luehdorfia. In contrast to both L. chinensis and L. longicaudata, nearer relation exists between L. puziloi and L. japonica.

The green slender planthopper, Saccharosydne procerus (Homeptera:Delphacidae) serves as a major alternate host of the egg parasitoid, Anagrus nilaparvatae, an important biocontrol agent of the rice planthoppers. Zizania caduciflora plants bearing numerous parasitized eggs of S. procerus highly promoted the A. nilaparvatae populations for the neighboring rice field, and efficiently suppressed the occurrence of the rice planthopper. In the free choice test, A. nilaparvatae emerged from eggs of either S. procerus or Nilaparvata lugens preferred N. lugens eggs to S. procerus. The parasitism of S. procerus by A. nilaparvatae exceeded 15%, while S. procerus eggs were alone provided. S. procerus could not complete its life cycle on rice, indicating no significant damage of this planthopper to rice. These results suggested that a proper management of rice and Z. caduciflora fields may enhance the efficiency of egg parasitoid, Anagrus spp. To control both rice planthoppers in rice field and S. procerus in Z. caduciflora field.

In the present paper, the studies were made on the damages of Tomicus piniperda (Col., Scolytidae) including the shoot feeding and the trunk attacking on Pinus yunnanensis trees in Yunnan Province, in southwestern China. The three basic damage patterns in the trunk attacking developed by the beetle were revealed. Tomicus minor and blue stain fungi were found to be involved in T. piniperda damages. The three damage patterns, in association with Tomicus minor and blue stain fungi, made the integrated function, which is proposed to strengthen the damages of T. piniperda to Yunnan pine trees.

The paper reports male stridulatory apparatus of Kuwayamaea sapporensis Matsumura & Shiraki,1908, Kuwayamaea chinensis (Brunner-Wattenwyl,1878), and Kuwayamaea longipennis sp. Nov. The three species differ from one another in male stridulatory apparatus. The specimens are deposited in Institute of Zoology,Shaanxi Normal University.

Three new species belonging to genus Mileewa，M. anchora sp. nov., M. ponta sp. nov. and M. papillata sp. nov. from Guizhou Province，China，are described.The type specimens are deposited in Agricultural College of Guizhou University.

Five species of Coleophoridae from China are reported in this paper. Among them, three species Coleophora jaculatoria sp. Nov., C. quadrifurca sp.nov. and C. yuzhongensis sp. nov. are described as new to science, and two species C. frankii Schmidt and C. pseudociconiella Toll are recorded for the first time from this country.

The genus Earinus Wesmael of the subfamily Agathidinae is recorded for the first time from the mainland of China. One species, Earinus wuyiensis Chen et Yang, is new to science. A key to Chinese species of this genus is also given. Type specimen is deposited in the Beneficial Insects Lab., Department of Plant Protection, Fujian Agricultural University,Fuzhou, Fujian Province.

The present paper deals with three new species of Muscidae, collected from the western region of Sichuan Province during the years 1979～1996, belonging to the genus Potamia Robineau-Desvoidy, 1830, Drymeia Meigen, 1826 and Limnophora Robineau-Desvoidy, 1830, i.e. Potameia setitarsis sp. nov., Drymia sichuanensis sp. nov. and Limnophora cinerifulva sp. nov. The type specimens are kept in the Medical Entomological Specimen Building, Academy of Military Medical Sciences, Beijing, China.

A new species, Neogamasus turbinatus sp. nov., is described and illustrated from Heilongjiang Province, China.

Teratocytes originating from the serosal membrane of an endoparasitic wasp embryo, which is one of the species found in the Hymenopteran families Braconidae, Platygasteridae and Socelionidae, act an important role in coordinating the relationship between the larval wasp and its host. It may be concluded that inhibiting the immune system of the host, regulating development of the host and nourishing the parasitoid larva are three major functions of the teratocytes. By means of releasing inhibitor of phenol oxidase, a fundamental ingredient of the immune system of the host, the teratocytes prevent the host from encapsulation, which is fatal to the parasitoid larva. In the process of parasitism, the teratocytes reduce ecdysteroid titer and inhibit the metabolism of JH in the hemoymph of the host, and subsequently result in the developmental arrest of the host larva. On the other hand, the teratocytes secrete proteins or present themselves as food to the parasitoid. Although all those above are generally acknowledged functions of the teratocytes, there are other putative functions of the teratocytes, such as secreting histolytic enzymes and mycostatic material, and protecting the host from overharmed by the parasitoid before the parasitoid emerges from its host. The studies in this area can provide us more understanding and knowledge about the relationship between a parasitoid and its host.