【Abstract】 Objective To understand the population composition of rat?shape rodents in Guangdong province and its breeding in different seasons, and to provide the theoretical basis for the control of rodents. Methods Rodents were caught daily by snap trap method in township sampled randomly monthly. The rodents captured were identified and dissected, recording the pregnancy situation. Results The trapping rate of rat?shape rodents was 9.98% in the residential areas, including 4.98% of rats. It included 48.73% Rattus norvegicus, 15.50% R.tanezumi mice, 35.17%Suncus murinus and 0.59% Mus musculus. The average pregnancy rate of R.norvegicus was 4.06% and the average litter size was 5.35. The average pregnancy rate of R.tanezumi was 5.63%  and  the  average  litter  size  was  2.76.  That  of  Suncus  murinus  was  15.00%  and  its  litter size was 3.32. Conclusion R.norvegicus and Suncus murinus are the dominant species in the residential areas in township. M.musculus is the rare specie. The breeding seasons of R.norvegicus and R.tanezumi are in spring and autumn, and the breeding peak in spring is higher than that in the autumn. It has also a small reproduction peak in August. However, Suncus murinus can breed all year round, and there are also two peaks. One peak is in March?June, the other is in October?November. It should strengthen the killing of rodents in spring and autumn.

【Abstract】 Objective To understand the population composition and seasonal fluctuation of fleas parasitized on Rattus tanezumi in Leizhou city. Methods R.tanezumi were captured in selected districts of Leizhou city from 1985 to 2004. Fleas were collected from their body surface and identified to count the flea index and its  composition  proportion.  Results A total of  1721 R.tanezumi were caught, and about 2345 fleas belonged to 4 species were collected. Among them, Xenopsylla cheopis and Leplopsylla segnis were the dominant species, the average index of them were 1.24 and 0.12, and the proportion of them were 91.13% and 8.66%, respectively. The index and composition proportion of  Pulex irritans and Ctenocephalides felis felis were very low. Conclusion R.tanezumi was the dominant host of X.cheopis and L.segnis. The number of X.cheopis increased year by year, but that of L.segnis decreased year after year.

Objective Study on the control ratios of rodents' parasitic flea and ground free flea after resort spraying on the ground in the focus of house mice plague.Methods After diluted the liquid with water(1∶160) 5% Fendona was resort sprayed on the indoor and the outdoor(80 ml/m ²) according to per house 100 g the powder,especially on the foot of a wall,the kennel,the holes and traces of rodents(150-180 ml/m ²).Through counted control ratios with the indices of rodents' parasitic flea and the ground free flea before the application and after the application.Results The control ratios of rodents parasitic flea and ground free flea are 33.54% and 71.39% respectively.Conclusion On-the-spot the control ratios of rodents' parasitic flea is very limited,but the rural sanitation is key to the question.

Objective To study some biological characteristics of Nosopsyllus wualis laizhouensis and Acropsylla episema girshami,to provide scientific evidence for evaluating their plague-vector efficiency. Methods Weigh the flea eggs,hungry fleas and the full blood fleas using the electronic scale,and calculate sucking amount of blood; Measure the diameter of the flea egg with wee ruler of microscope. Results The long and short diameters of eggs of Nosopsyllus wualis laizhouensis were ( 0.636± 0.035)mm,(0.360± 0.017)mm respectively,and the Acropsylla episema girshami's were ( 0.536± 0.024)mm,(0.256± 0.011)mm respectively; The average weights of the eggs were 0.055 mg,0.029 mg respectively; The average weights of hungry fleas and the full blood fleas of Nosopsyllus wualis laizhouensis were ( 0.364± 0.134)mg,(0.523± 0.198)mg respectively,and Acropsylla episema girshami's were (0.179± 0.050)mg,(0.230± 0.062)mg respectively. The average sucking amounts of blood of the two species of fleas were(0.159± 0.082)mg,(0.050± 0.021)mg respectively. Conclusion Compared with the Acropsylla episema girshami, Nosopsyllus wualis laizhouensis has heavier weight as well as larger size of egg,and the average sucking amount of blood is more.

Objective To study the biological characteristics of Ctenocephalides felis felis,and to offer basic data for prevention and control of the fleas.Methods Rearing adult with mice blood and larvae with artificial diet under the conditions of constant temperature and humidity,separatively. Results At(23±1)℃,relative humidity(85±5)%,the metamorphic period was(24.80)(18-29)days.It laid(778.90 eggs/♀),and laid(5.67 eggs/(♀·d)).The reproductive capacity was(2.57).Life-span of the fleas is(18.10)(12-24)days for starved infancy,and(122.73)(33-255)days for adults of blood-sucking.Conclusion Metamorphic period of Ctenocephalides felis felis is short,life of the adult is long,and the reproductive capacity is strong.

Objective To study the behavior of Nosopsyllus wualis laizhouensis and Acropsylla episema girshami biting and sucking human blood,to provide evidence for evaluting the significance of N.w.laizhouensis and A.e.girshami in plague disease epidemiology. Methods Fix fleas fixed on volunteer's antebrachium and crus,to bite and suck freely. Results The sucking rate of N.w.laizhouensis is 63.48%,there were no significan differences among the sex of flea,man's age,man's blood type and position of biting. The sucking rate of A.e.girshami is 11.71%,the selectivity on man's blood type and position of biting was found in our study. Conclusion They all can bite and suck man's blood. The biting and sucking blood ability for N.w.laizhouensis is stronger than for A.e.girshami,and both of them are great significance in plague epidemiology.

Objective To study the dynamic of resistance in commensal rodents and it's management strategy in Zhanjiang,Guangdong province.Methods Based on the resistance monitoring data and density of commensal rodent( Rattus flavipectus and Rattus norvegicus) to reveal the variation law.Results The resistant population of R.flavipectus was fundamentally evoluted after anticoagulants used for 17 years,the resistance individual rate was 17.7%(10.6% 33.3%),which was significant differences( P<0.05) between different areas or different rodents in the same area.Conclusion R.flavipectus has fundamentally developed resistant to anticoagulants in Zhanjiang,it was suggested that we must pay more attention to rat resistance monitoring,according to this resistance dynamic and development of the resistance,integrated preventive management against rats including reasonable drug used should be applied.