Through observations on the rate of ovarian development, quantitative analysis of soluble protein and nucleic acid, rocket immunoelectrophetic measurment of vitellogenin titer in hae-molymph and hormone treatments, the inhibitory effec, of precocene II on vitellogenesis in tile housefly Musca domestica vicina was investigated. When the newly-emerged femalehouse-flies were topically treated with precocene II in 20 ug/fly, vitellogenesis was temporally inhibi, ed and the development was delayed 12 hours than that of the control. At 48 hours aftertreatment, the titer of vitellogenin in haemolymph was 10.5ug/ul, nearly the same as the control, but the development of ovary was retarded as compared with the contro. This temporalinhibitory effect seemed to indicate tbat the uptake of vitellogenin by oocyte was partially in hibited. When the treatment was in high doage abom 100 ug per fly, the titer of vitellogeninin hemolymph and the weight of overies, ,oral protein and RNA in ovaries were obviously lower when compared with the control, indicating that the development of the ovary and the synthesis of vitellogenin wer inhibited It was observed that the inhibition could be restored naturally. When the treatment of precocene II was followed with application of JH Ill, the inhibition of vitellogenesis was not conspicuous and the titer of vitellogenin in haemolymph was two times that in temporally inhibited flies. When precocene II treatment was followed with to pical application of 20-hydroxyecdysone, the vitellogenesis was still inhibited. The mode of action of precocene on ovarian development of dipteran insect is discussed.

A genomic library of silkworm Bombyx rnori (Chinese species Dongfei×Huahe) was constructed. 12-20 kb DNA fragments from partially digested silkworm genomic DNA withsau3A were recovered and inserted into the BamHI site of the bacteriophage vector Λembl4. The recombinant molecules were packaged in vitro and amplified to a permanent library. The number of the bacteriophage recombinants was 5.5X10⁵ pfu. This number exceeded the theoretical number necessary to cover the whole genome. Futher examination showed: 1. The phenotype of bacteriophages in the library was Spi^-; 2. Different recombinants contained dif-ferent foreign DNA fragments; 3. After screening the library by hybridization, some recom binants containing the foreign DNA homologous to the probe of mosquito esterase BI gene had been isolated. These results demonstrated the reliability of the library.

The effective factors causing the production of alatae in soybean aphid Aphis glycineswere studied in the laboratory. The result shows that crowding of adult apterae plays a main role in the production of alatae, but nymphal apterae are not sensitive to crowding. Although more alatae will be produced when crowding is intensified in colonies of low population, the responses decrease with the overcrowding condition. The quality of soybean leaves is not afactor determining the production of alatae, btu it may change the response of the crowded apterae females to crowding. Aphids starved for 24 hours in isolation give no response to the soybean leaf quality. Temperature and parentage are other factors influencing the propor tion of ala, ae in the progeny of the apterous females. Higher temperature depresses the appearance of winged aphids through the embryo within the apterous females The ala'ae are less sensitive to crowding than the apterae.

The adult bee, le Anoplophora horsfieldi (Hope) adopts two different ways in sound production, I.e, thoracic stridulation and elytral vibration. The thoracic stridulation sounding(TSS) may be produced successively and plays the role of both enemy repelling and intraspe cific communication. The elytral vibration sounding (EVS), which is produced non-succes sively and induced by external stimulus, has the role mainly for enemy repelling. The TSS consists of a series of sound groups, each of which, running about 1100 to 1600 ms, ordinally consists of up-stroke syllable (US) (384±22 ms, 250-350,) pulse train(PT) interval 1 (270-600 ms), down-stroke syllable (DS) (382±16 ms, PT 250-350) and interval 2 (80-360 ms). The power-spectrum of US is formed by the basic sound (BS) and its partial. The BS gives the main part of the signal power and the main peak frequency at 742±30 Hz in males and 603±34Hz in females. The EVS consists of 7 to 9 PT with higher amplitude and frequency and running about 7 to 10 ms. Though the frequencies of EVS's PT distribute from 0 to 3100 Hz in the power-spectrum, the power mainly lies within 850 to 1050 Hz. The EVS of the beetle is a more effective display in enemy repelling by its higher energy content and sudden release as compared with TSS.

he optical superposition images and field angle of the compound eye of Beijing firefly Phrococelia pekinensis was observed by means of optical imaging under different adaptation states. Crystalling cones could form a real superposition image at a distance of 300-350μmfrom the surface of cornea (correspond to the level of retina) under different adaptation states. A real optical superposition image was formed by dark-adapted crystalline cones for an object at different distances and its size decreased as the object distance increased. For the lightadapted crystalline cones the range of object distance became smaller and the brightness of superposition image became lower than they were with dark-adapted crystalline cones. Bleached crystalline cones could form a superposition image only at a certain distance and the bright ness of image was lowest in the three cases. Differem number of crystalline cones could form the same superposition image but the increase in image sharpness arose from the increase in　umber of the crystalline cones. According to the observation in the field of part of the compound eye and the characteristics of its structa re, the field angle of the compound eye of the Beijing firefly was found to be over 180°

It was observed that during copulation air bubbles were introduced into the bursa copula trix from the male aedeagus in Sitotroga cereallela. This study was to find our in thisphenomenon the source of air, tile air pathway and the initiation and action of the air expelling. The resu. Lsa indicated that the air bubbles came from the tracheoles on the hinder portion of the ductus ejaculatorius, they travelled along the inter-space of the tubular structure to the aedeagus and were expelled through a pore located near the aedeagal extreme. It is inferred that air expelling is the result of enhaneed me'abolism of the ejaculatory duct in the formationof spermatophores.

Dilute solutions of atrazine and dichlorvos were used to treat the larvae of cotton boll worm Heliothis armigera and housefly Musca domestica vicina by topic application or mixing them with the diets for rearing the larvae. The activities of carboxylesterase (CarE) and glutatione-S-transferase (CST), using the supernatant protions of the homogenates of the larvae,were determined according to the methods of Asperen (1962) and Habig ct al (1981) respec tively. The results showed that atrazine induced Gate and GST activities significantly in the cotton bollworm to about 146% and 280% respectively. The peak of Care activity induced byatrazine appeared earlier than that of GST. Both the time and magnitude of Care or GST activity varied with the amount of atrzine used in the topic application. In the larvae of house fly, dichlorvos was very poor inducer of Care or GST activity and atrazine could not increase GST activity.

It has been shown that the natural product, (-)-polygodial extracted from Polygounm hydropiper L. prossesses very good antifeedant activity to instects. Methods of extraction, purification and content measurement of this natural product are reinvestigated in our laboratory.The content of polygodial in the leaves of the plant in China is about 0.08%. The half-life of　synthetic polygodial in air, under light and in heat (55-60℃) are 34.6 days, 33.8 days and 15.6 days respectively. The results of indoor and field tests showed that the nature polygodial extracted from the plant by ethyl ether can be used against aphids.

Studies on chemical control of the pine armoured scale seriously infests pine trees were conducted during 1988 and 1989 in Guangdong Province. Through a series of screening tests for effectiveness of 16 synthetic insecticides in tile laboratory, field trials and experiments by aerial spray applications of promising materials (including various formulations of oil emul sions) in the forest, we succeeded in estatblishing the outstandingly high effectiveness of an oil emulsion, a product which we formulated by mixing the rubber tree seed oil (or chinaberry seed oil) with the diesel oil at a ratio of 3:7 with an emulsifier in an appropriate amount. Results of field trials by ground spray application of the test materials showed that at con centration of 5%, the product gave a high control of the scale insect up to 90-100%. In two experiments using aerial spray application of the materials it was shown that this mixture when diluted with water at 1:4 equivalent to 75 kg/ha gave a control efficiency above 70%, which means much more potent than the conventional pine resin-diesel oil mixture commonly used inHui-Ding County, Guangdong Province and other places. Meanwhile, this produc' was found to be safe to Encarsia sp. And Alphytis sp., hymenopterous parasites as the most important naturalenemies of the pine armoured scale and proved to have no harmful effect on the environment. Furthermore, the formulation can be easily pre pared as an emulsion. It is suggested that the product could be widely used for the effective control of the pine armoured scale and other insects infesting the pine trees.

For appraising the effect of mosaic control on evolution of insecticide resistance, we simu late the effect in the laboratory by using a syn thetic population of Culex pipiens pallens as model insect. A synthetic strain (M) was constituted at the R individual frequency of 0.1 for both malathion and fenvalerate (named RM for monofactorical and RF for polyfactorical, re spectively) And then the M strain was divided into three sub-strains at F_l. The Rmf sub strain was treated by mosaic control with malathion and fenvalerate, and compared with Rm and Rf sub-strain which were treated separately with one of the above insecticides. After 10 generations, the resistance of Rm and Rmf to malathion was 266.4- and 6.1-fold, respectively, but the resistance of Rf and Rmf to fenalerate was both more than 243.3-fold only after 5 generations The simulation results showed (I) that mosaic control with unrelated insecticides could retard resistance development in given conditions and (2) that it was extremely effective for monofactorical but little for polygenictraits. The strategies for resistance management are also discussed.

This paper reports 25 cases of male fleas castrated from Heilongjiang, Jilin, Nei Mongol, Ningxia, Gansu, Hebei and Yunnan Provinces, China. They belong to 6 species (or subspecies) in genus Neopsylla: N. abagaitui (3 cases), N. bidentatiforrnis (9 cases), N. cornpar(1 case), N. pleskei orientalis (4 cases), N. sellaris (7 cases) and N. S. Specialis (1 case).The morphology of teratogenic fleas are described. Taxonomic position about Neopsylla rnonodenfatiforrnis Huang et Xie, 1987 (Ssichuan J.Zool. 7(1): 5-7) are also discussed. It will be possible that the name Neopsylla monodentati formis might be treated as an excluded name by tile International Code of Zoological Nomen clature because the name bearing type based probably on teratological specimens in N. biden.Tatiformis.