【Abstract】 Objective To verify the effect of simvastatin on the population dynamics of Blattella germanica. Methods Two groups of B.germanica were reared with feedstuff containing 0.001% simvastatin and common feed, respectively. The population quantity of different development stages of B.germanica and their constitution ratio were investigate after breeding for different time. Results The quantity of adult cockroaches with oothecae in the tested group reduced gradually after treatment for two months, six months and eight months, respectively. Accordingly, the quantity of male and female adult cockroach also decreased gradually. The nymphae quantity after treated for four months was two times than that after treatment for two months. However, it decreased rapidly in the sixth month, and the quantity of female adults and adults with oothecae reduced to zero in the eighth month. The quantity of male adults and nymphae was 2 and 15, respectively. The quantity of adults with oothscae was all higher than the initial number after they were bred with common feed for two months and six months. But in the forth month, it decreased a little compared to the initial number. And, it was basically equal to the initial number in the eighth month. With the decrease of the adults with oothecae, the quantity of male and female adults also reduced gradually. Similar to the tested group, the nymphae quantity in the control group was the highest after breeding for four month, and then it gradually decreased. In the eighth month, there were 78 nymphae, 5 adult cockroaches with oothacae, 8 female adults and 12 male adults. Conclusion B.germanica would lose the capability of its population restoration after breeding with feed containing 0.001% simvastatin for eighth months.

Objective The high cyhalothrin resistant Musca domestica strain(Cyh-R) was further selected by deltamethrin and pirimiphos-methyl to study the difference of toxicity and to explore the methods of flies resistance management.Methods(Chy-R) strain was regularly selected with deltamethrin and pirimiphos-methyl by spray method,the former named ZX strain,the later named ZJ strain.(Cyh-R) was selected with no insecticide and normal bred,named ZS strain.The toxicity of the cyhalothrin was tested in generations of different resistant strains every twice after selection with topical application bioassay,to compare the difference with(Cyh-R) strain no-selected.Results The(Cyh-R) strain was 561.9-fold resistant compared with insecticide resistant strains at LD ₅₀.The LD ₅₀ of ZJ strain from F ₂ to F ₆ showed declining trend,the resistance factors at LD ₅₀ declined from 518.2-fold of F ₂ to 110.3-fold of F ₄ and to(122.6)-fold of F ₆.The LD ₅₀ of ZX strain from F ₂ to F ₈ showed declining firstly and increasing later,the resistance factors at LD ₅₀ increased from 217.2-fold of F ₄ to(808.0)-fold of F ₈.The resistance factors at LD ₅₀ of ZS strain declined to 242.3-fold of F ₈.Conclusion The high insecticide resistant strain to cyhalothrin was selected with organophosphates,could decline resistant to cyhalothrin.The strain was selected with pyrethroids,could cause resistance elevated higher to cyhalothrin.The strain was selected with no insecticide,could also prohibit resistant development to cyhalothrin,but the ratio of decline was lower than pirimiphos-methyl selected.

Objective To compare the efficiency of insecticides toxicity to different houseflies strains with two methods.Methods Using topical application method and feeding test method to test the efficiency of insecticide toxicity to different houseflies strains.Results To laboratory sensitive strains(Lab),the ratio of the topical application bioassay comparing with the feeding bioassay ranged from 0.48 to 1.69 at LD ₅₀/L ₅₀.To Lamda-cyhalothrin resisitant strains (Cyh-R),the ratio ranged from 0.71 to 87.13 at LD ₅₀/LC ₅₀,for male houseflies of(Cyh-R) strains the difference was relatively small.Conclusion For susceptible housefly strains,the insecticide toxicity can be tested using topical application method or feeding test method,the results is similar.But for resistance strains,two methods should be used,especially for insecticide for baits formulations.

Objective To find out the population of Dengue vector and the rish degree of Dengue emergence and the breeding habit and distribution of vector in Shanghai area.The result was basis to provide guidance for Dengue control.Methods The larva collected from different area and container was identified for species and the positive rate of larva was checked.The man-alluring-biting method was used to survey the rate of biting during April-November,2001.Results(1) Aedes aegypti was not discovered in Shanghai, Aedes albopictus only.(2) Aedes albopictus> larva was discovered during April-November;The Aedes albopictus larva density peak was in June-September.(3)During June-September,the Aedes albopictus container index(CI) was 8.59%;the house index(HI) was 8.90%;the Breteau index(BI) was 12.19%;the larval density index(LDI) was 2.16;The biting rate index(BRI) was 16.6 sets/per man power hour;The density of Aedes albopictus was equal to WHO three degree.It has risk for Dengue to spread.(4)The Aedes albopictus larva distribution was extensive,in tyre.,Jar.,Vat and the container from flower and from house.(5)The positive rate was different between the city and country,and between the different unity,area and house.Conclusion The Dengue vector is Aedes albopictus and its population has risk degree in Shanghai;The surveillance on population density and vector energy should be conducted every year.The control method for Dengue vector Aedes albopictus should be studied.

After the cockroaches take in the Secondary Kill Roach Baits,the A.I.decomposes little and excretes with excrement or remains in the flesh of the cockroaches as original.The other matures or nymphas will be affected by taking in the excrement or the flesh of insect.That is secondary kill effect.This article provided a new secondary kill effect test method.This method proved the secondary kill effect of the Combat Roach Baits in a scientific and rigorous way.The secondary kill (nymphas) motalilty rate was 89.37% in the 3th day and 100% in the 6th day.This method had been affirmed by relative department and won high praise.