Objective To explore the relationship between the resistance of Rattus losea and its metabolic detoxifying enzymes under the selective pressure of anticoagulant rodenticides, and to lay a foundation for elucidating the resistance mechanism. Methods A microplate reader was used to determine the contents and activities of cytochrome P450 (CYP450), NAD(P)H quinone oxidoreductase 1 (NQO1), and cytochrome b5 (Cytb5) in serum and liver of R. losea; meanwhile, comparative analyses were performed between different populations for the relationship of the difference with resistance level. Results The content and activity of detoxifying enzymes in liver were higher than those in serum in both sensitive and resistant R. losea populations in Jiangmen, Guangdong province, China. The content and activity of NQO1 and the content of Cytb5 in liver were significantly higher in the sensitive rodents than in the resistant rodents ( t ₁=2.408, P ₁=0.037; t ₂=2.515, P ₂=0.031; t ₃=2.281, P ₃=0.046). However, there were no significant differences in the contents and activities of the three enzymes in serum, the content and activity of CYP450 in liver and the activity of Cytb5 (all P>0.05). Conclusion Among the three enzymes, only the content and activity of NQO1 and the content of Cytb5 in the liver are related to the insecticide resistance of R. losea. It is speculated that the resistance of rodents to anticoagulant rodenticides is a synergistic effect of multiple factors. Therefore, a comprehensive analysis of multiple factors should be performed to better clarify the mechanism of action of rodents' resistance to anticoagulant rodenticides.

Objective To identify and analyze the rodents captured in the farmland in Xinhui district, Jiangmen, Guangdong province, China, using DNA barcoding technology, and to lay a foundation for the diversity study of murine-like animals and rodent prevention and control. Methods Forty-five rodents captured in the farmland in Xinhui district, Jiangmen, Guangdong province, in December 2017, were enrolled as study subjects. Their genetic DNAs were extracted and amplified for mitochondrial cytochrome c oxidase subunit I gene fragments using consensus primers. The gene fragments were sequenced and the results were subjected to sequence homology analysis using BLAST in the National Center for Biotechnology Information. The molecular evolutionary tree was constructed by the neighbor-joining method. Genetic distance was calculated based on a two-parameter model. Results Specific gene fragments of the forty-five samples were obtained by PCR amplification. Four species of rodents ( Rattus losea, R. tanezumi, R. norvegicus, and R. andamanensis) were identified through BLAST comparison. Thirty-seven samples had identification results identical to the morphological identification ( R. losea), and eight samples had erroneous morphological identification results, among which five were reidentified as R. tanezumi, two were reidentified as young R. norvegicus, and one was reidentified as R. andamanensis, according to the review of the initial results. A total of 131 mutation sites were identified through alignment and analysis of the 45 sequences, and 12 different haplotypes were identified through haplotype analysis. The intraspecific genetic distance of R. losea was 0-1.2%, the interspecific genetic distance was 7.1%-11.6%, and the mean genetic distance was 10.1%±0.7%. The NJ tree showed that individuals of the same rodent species were clustered into one branch with a 100% support rate, which could distinguish among different rodent species. Conclusion The DNA barcoding technology can effectively distinguish between related species with similar morphology and correct the erroneous results of morphological identification.

Objective To investigate the resistance of Rattus losea to the first-generation anticoagulant rodenticide in Xinhui district, Jiangmen, Guangdong province, China, and to elucidate the relationship between vitamin K epoxide reductase complex subunit 1 ( VKORC1) gene mutation and rodenticide resistance. Methods The lethal feeding period test was used to determine the resistance of R. losea. The genomic DNAs of the rodents were extracted to clone the VKORC1 gene and screen out mutation and polymorphism sites. Meanwhile, the correlation between VKORC1 gene mutation and resistance was analyzed. Results The resistance rate of R. losea to the first-generation anticoagulant rodenticide was 27.03%, indicating the formation of a resistant population. The total length of the VKORC1 gene was 2 166 bp. A total of 12 mutation sites were detected and one of them was an insertion-deletion site. Exon 1 and exon 3 each had one mutation site, while intron 1 and intron 2 had six and four mutation sites, respectively. The exon 1 mutation resulted in an amino acid mutation at site 58 (Arg58Gly) and the exon 3 mutation was a synonymous mutation (Cys96Cys). A correlation analysis showed that there was no significant correlation between rodenticide resistance of R. losea and single nucleotide polymorphism site of the VKORC1 gene ( P>0.05). Conclusion The site 58 amino acid mutation of the VKORC1 gene is not the main cause of rodenticide resistance in R. losea. The genetic mechanism of rodenticide resistance in R. losea may be related to other factors.

Objective Two previously unknown rodent species were identified by DNA barcoding from Yangchun city, Guangdong province. Methods Genomic DNA was extracted from samples, and the mitochondrial cytochrome c oxidase subunitⅠ genes were amplified using universal primers (BatL5310 and R6036R), then sequenced. BLAST comparison was subsequently carried out in NCBI. The phylogenetic tree was constructed using the Neighbor-Joining method. Genetic distances were calculated based on double parameter model. Results DNA sequences from two samples were consistent, suggesting they were the same species. It showed high sequence similarities with Berylmys bowersi(99%) in GenBank. In addition, genetic distance with B. bowersi was 0.004 6, less than 1% threshold of intraspecific genetic distance. Therefore, the unknown species was B. bowersi. Conclusion DNA barcoding is a highly effective approach to rapidly identify species, which could make up the shortages of morphological taxonomy.

Objective To clarify age structure and fecundity of Rattus norvegicus population in Zhanjiang city, providing theoretical basis for early warning and formulating scientific prevention and control measures of rodent pests. Methods Rattus norvegicus were captured by cage traps from 2008 to 2011. Body weight, carcass weight, body length and tail length of test rats were measured. Reproductive organs were anatomized and developmental status was observed. Age groups were divided according to the frequency distribution characteristics of body weight and the developmental and reproductive status. Results Rattus norvegicus were divided into five age groups, juvenile group (Ⅰ,≤120 g), subadult group (Ⅱ,120-180 g), adult groupⅠ(Ⅲ, 180-240 g), adult group Ⅱ(Ⅳ, 240-390 g), and old group(Ⅴ, >390 g). Body weight and carcass weight between neighboring age class had extremely significant positive correlation. The overall fitting degree of age class based on body weight and carcass weight was high and the frequency dissimilarity rate was only 4.54%. The pregnant rate of the females kept increasing in all age classes and reached peak at age class Ⅳ. The average fetus and reproductive index kept increasing in all age classes. The size of testes kept increasing with age and the descending rate increased from 15.79% to 100%. Conclusion It was feasible to identify age classes by body weight. The population fecundity of R. norvegicus in Zhanjiang city kept growing in all age classes. The breeding population was mainly the adults and the old individuals.

Objective A new type of automatic mousetrap system and its application effect were studied to provide efficient and environmentally friendly control techniques for rodents. Methods Mouse preferred food was selected for screening test of lure in the trap. The rodent density and rice rodent infestation ratio was investigated to evaluate the control effect of automatic mousetrap system. Results Research has showed that field grown mature period of sweet corn and rice sprout was the preferred lure of automatic mousetrap system. From 2012 August to November, the automatic mousetrap system has captured 141 rodents, mainly Rattus losea and R. norvegicus. After implementation of automatic mousetrap system for three months, the rat trace index decreased by 80.94% and 77.46% reduction in rice rodent ratio. Control effect was obvious. Conclusion Automatic mousetrap system and its application method provided a new technology for sustainable rodent control.

Objective To investigate the influence of urbanization on the structure of rodent community in different habitats in the rural areas, and to provide a scientific support for carrying out rodent control. Methods Night trapping method was used to investigate rodent community structure in the rural areas after urbanization. Three hundred traps were set in each sample region. The distance between traps was 5 m and the interval between survey lines was above 50 m. Traps were placed at dawn and collected in dusk. Results The urban-rural encroaching zone became the most important habitat for rodents after urbanization. The number and biomass of house mice increased greatly, while the dominance of voles significantly decreased. In the urban-rural encroaching zone, Rattus norvegicus was the most predominant species and the most pestiferous rodent. In the farmland 500 m away from the town, R. losea was the most predominant rodent and R. norvegicus was the secondary; Bandicota indica, R. norvegicus, and R. losea were the most pestiferous rodents. In the farmland 2 km away from the town, R. losea was the most predominant rodent and Mus musculus was the secondary; R. losea and B. indica were the most pestiferous rodents. Conclusion Urbanization indirectly provides favorable conditions for rodent infestation, with some changes in farmland rodent community. Sustainable management should be strengthened in the face of such changes.

Objective To investigate the influence of urbanization on the structure of rodent community in different habitats in the rural areas, and to provide a scientific support for carrying out rodent control. Methods Night trapping method was used to investigate rodent community structure in the rural areas after urbanization. Three hundred traps were set in each sample region. The distance between traps was 5 m and the interval between survey lines was above 50 m. Traps were placed at dawn and collected in dusk. Results The urban-rural encroaching zone became the most important habitat for rodents after urbanization. The number and biomass of house mice increased greatly, while the dominance of voles significantly decreased. In the urban-rural encroaching zone, Rattus norvegicus was the most predominant species and the most pestiferous rodent. In the farmland 500 m away from the town, R. losea was the most predominant rodent and R. norvegicus was the secondary; Bandicota indica, R. norvegicus, and R. losea were the most pestiferous rodents. In the farmland 2 km away from the town, R. losea was the most predominant rodent and Mus musculus was the secondary; R. losea and B. indica were the most pestiferous rodents. Conclusion Urbanization indirectly provides favorable conditions for rodent infestation, with some changes in farmland rodent community. Sustainable management should be strengthened in the face of such changes.

Objective Rodent infestation monitoring is the foundation for rodent management in farmlands. The current study is to evaluate rodent population dynamics in the farmlands in Guangdong province, China, to compare the rodent density indices reflected by different methods, and to provide important baseline data for population management. Methods The rodent trace method and night trapping method were successively used to determine the rodent densities in the sampling areas. Rodent trace method: Two test lines were set along the irrigation channel or ridge, with a distance of more than 50 m in between; 50 mud stations (20 cm×20 cm) were set at a gap of 5 m on each test line. Night trapping method: Three hundred traps were set at night in each month; the distance between two traps was 5 m, and the distance between two test lines was more than 50 m; these traps were placed at night and collected in the morning of the next day. Results In the farmlands in Guangdong, the annual fluctuation in the density of rodent pests presented a bimodal pattern, and there were two peaks (in August and December) and two valleys (in September and February-March) every year. The capture rate, positive rate of rodent traces, and rodent trace index reflected the fluctuation in rodent population well and showed a significant linear positive correlation between each other; the linear regression equations were as follows: capture rate (Y)-positive rate of rodent traces (X): Y=0.115X＋1.119; capture rate (Y)-rodent trace index (X): Y=0.333X-1.078; positive rate of rodent traces (Y)-rodent trace index (X): Y=2.766X-16.332. Conclusion Night trapping method and rodent trace method have different advantages in the assessment of rodent populations in Guangdong farmlands and should be selected strategically according to specific circumstances.

Objective To study the safety of compound sterilant CQ-1 in chickens. Methods Sterilant baits (0, 10, 15, and 20 mg/kg) were used to feed chickens for 10 consecutive days. All test chickens were dissected after 30 days of observation. The indices, such as general signs, food consumption, body weight, egg-laying rate, and organ coefficient, of the sterilant-fed chickens were recorded and compared with those of control group. The safety of compound sterilant CQ-1 for non-target animals was evaluated. Results No obvious abnormity was observed in any of the chickens fed with the sterilant. The control group had a maximum food consumption of 0.44±0.12 g/kg, and the 3 sterilant treatment groups had significantly less food consumption than the control group. The 20 mg/kg treatment group had a pure drug consumption of 4.20±1.44 μg/kg. The 3 sterilant treatment groups had temporary decreases in body weight, while the control group had a sustained increase in body weight. The egg-laying rate decreased in the 3 sterilant treatment groups, most (down 49.3%) in the 15 mg/kg treatment group. On days 41-50, the egg-laying rate rose and returned to normal in the 3 sterilant treatment groups. No abnormal organs were found in the 3 sterilant treatment groups after dissection, and there was no significant difference in organ coefficient between the treatment groups and the control group. Conclusion Compound sterilant CQ-1 has little toxicity to chickens. Chickens do not die after being fed with the sterilant at 20 mg/kg for 10 consecutive days. Although the body weight and egg-laying rate decrease temporarily in sterilant-fed chickens, the two indices can return to normal later.

Objective To determine the resistance to the first-generation anticoagulant rodenticide in Rattus losea in the farmlands of Guangzhou city, China and investigate their avoidance behavior to poison bait or nontoxic bait, and to provide a basis for rodent control. Methods The resistance of R. losea was determined using the method established by Rodenticide-resistance Monitoring Cooperation Group in China. The avoidance behavior was studied by successive poison bait supply experiments. Results The percentage of R. losea which developed resistance to the first-generation anticoagulant rodenticide reached 83.33% in Guangzhou. Evident avoidance behavior to warfarin bait was seen in R. losea, and the bait shyness rate reached 30.00%. In the successive poison bait supply experiments and nontoxic bait supply experiments for rodent that survived after resistance determination, the poison bait shyness rate deceased generally in each experiment, but there was no significant change in the avoidance behavior to nontoxic bait. As the time of poison bait supply increased, the proportion of R. losea individuals with bait shyness rose, and the degree of nontoxic bait shyness was even higher than that of poison bait shyness in the first poison bait supply experiment. The daily intake of poison bait also deceased significantly, and the daily intake was still lower than those in the first and second poison bait supplies when R. losea was given nontoxic bait after the poison bait supply experiments. Conclusion The avoidance behavior of R. losea in Guangzhou to poison bait and even nontoxic bait indicates that R. losea has developed resistance to the first-generation anticoagulant rodenticide, which would be a big challenge to rodent control. This study provides an important guidance for improving rodent control effect.

Objective To investigate the feasibility of blood clotting response (BCR) test for determining the resistance to anticoagulant rodenticide in Rattus losea. Methods Sensitive and resistant populations of R. losea were screened out by a single gavage of warfarin at a discriminating dose of 10 mg/kg and lethal feeding period test. Plasma was collected from test rats at different time points; the standard curve of BCR was established by measuring the percentage clotting activity (PCA) of plasma, and the difference in PCA between resistant and sensitive individuals treated with a discriminating dose of warfarin was analyzed. Results The standard curve of BCR in R. losea was established as follows: INR(y)=34.984/x+0.688(x=PCA)(R²=0.992). After the single gavage of warfarin at a discriminating dose of 10 mg/kg, the PCA of resistant individuals decreased, but it was restored to 17% of normal level within 2-3 d; the PCA of sensitive individuals decreased dramatically and was not restored. Conclusion This study confirms the feasibility of BCR test for determining the resistance to anticoagulant rodenticide in R. losea. It is accurate and simple to differentiate resistant and sensitive individuals of R. losea by a single gavage of warfarin (10 mg/kg) and using PCA=16.5 (or INR=4.4) as the threshold 4 d later.

Objective To investigate the resistance of Rattus norvegicus to the first-generation rodenticide, warfarin, in Zhanjiang, Guangdong. Methods Rats sampled from the urban areas were screened with a trial test indoor for non-selective feeding with baits containing 0.005% warfarin to observe the dose-response relationship. Results Among 37 eligible candidates for the resistance test, 29 were dead due to administration. The resistance of R. norvegicus was 21.62%, indicating the formation of a resistant community. There was no significant difference in the lethal dose and time between male and female rats (P＞0.05). The average intake of poison baits was 19.14±5.44 mg/kg, and the average time to death 7.34±3.51 days. Conclusion The first-generation rodenticide was no longer an agent of choice for control of R. norvegicus in Zhanjiang. Monitoring the changes in the resistance among rodent population was necessary for optimal allocation of resources.

Objective To determine the optimal rodenticide bait for the farming areas in Guangdong province. Methods Different formulations were screened in terms of palatability and applied indoors to evaluate their effects on major rodent species detrimental to the farming industry in Guangdong. Results Compared to crops, the Basic Formulation C＋ Attractant Ⅱ and Basic Formation G＋Attractant Ⅰ, which topped the screening, had the acceptance coefficient of 2.97, 2.89 and 1.76 for Rattus losea, Bandicota indica and R. norvegicus respectively. The two formulations were well palatable. Conclusion The study provide information for the application of rodenticide bait in future.

Objective To measure the resistance of Rattus tanezumi to the 1^st generation agent after their exposure to the 2nd generation anticoagulant rodenticides for several years in Leizhou city, Guangdong province. Methods Rats captured in Leizhou suburb were raised indoor for days. Eligible rodents were subject to non-selective feeding test using 0.005% warfarin baits. The relationship between the mortality and intakes was recorded and analyzed. Results Among 36 eligible rodents, 32 died from the consumption of agents. The development of warfarin resistance in the subjects, 11.11%, was close to the critical level of development of population resistance. There was no significant difference in the lethal dose and lethal time between male and female rats (df＝30, P_d＝0.987, P_t＝0.971). The average volume of toxicant intake was (115.71±53.84) mg/kg for dead rats, with the average lethal time of (7.2±2.4) d. Conclusion The changing trends of rodent sensitivity to anticoagulant rodenticides should be regularly monitored during the application of these agents for economically optimizing the use of drugs.

Objective The daily intake in and preferences for field crop seeds and fruits in Bandicota indica were measured and determined, and the relationship between their food intake and the gender, age, weight and seasonal changes was analyzed in order to provide the basis for determination of the hazard of B. indica and development of sustainable control technology. Methods The animals were artificially fed in the laboratory and subject to both unselective and selective experiments indoors. Results Different crops had the respective intake masses as follows: dry rice (37.48±5.98) g, fresh rice (95.57±7.85) g, sweet potatoes (229.84±26.86) g, sweet corn (259.12±27.68) g, peanuts (101.92±20.40) g, soybeans (40.42±6.56) g, vegetables (377.96±52.33) g, and sugarcane (262.29±34.77) g. The intake masses of all crops in male rats were greater than those in female ones except for soybeans, while the intake masses of all crops in infant rats where higher than those in adults and subadults except for sugarcane. A significant to extremely significant linear correlation between the food intake and body weight was also shown. As for the seasonality, the food intake peaked in winter, moderated in autumn and reduced to the smallest in summer. The results of selective experiments showed that the preferences of B. indica for different crops were in descending order as follows: fresh rice, sweet corn, sweet potato, dried rice, peanuts, soy, sugarcane and vegetables. Conclusion The food intake of B. indica was highly related to the dry matter content and nutritional value, animal metabolism, growth rate and external environmental conditions. The preference index can be used to accurately reflect the different degrees of food preferences in rodents.

This study presents an overview of the current situation of the natural foci of plague in China and the research progress of genotyping of Yersinia pestis, as well as the impact on plague epidemiology  by the present socio?economic development and changes in the ecological environment in China. Corresponding prevention and control measures are proposed.

Objective To analyze the dietary composition of Bandicota indica to unearth the seasonal and annual patterns of the food structure, providing theoretical foundation for the development of scientific control countermeasures and sustainable management. Methods The contents of rat stomachs were analyzed in conjunction with field observation. Results Fibers accounted for (68.68±5.17)% in the gastric contents of the rats, while starch food (23.06±4.32)% and animal food (8.26±1.43)%, respectively. Significant differences were found in the gastric contents of subjects of different age, sex and in different seasons and years (P＜0.01). The proportion of starch and animal food in females was significantly greater than that in males. No significant differences were found in starch and fiber food consumed by the juvenile versus that by the sub-adults and adults, though the juvenile had higher intake of such kind of food (P＞0.05). However, the proportion of animal food consumption in adults was significantly higher than that in sub-adults and juvenile (P＜0.01). Considerable seasonal disparity in the food structure, characterized by higher amount of starch and animal food in summer and autumn and higher amount of fiber food in winter and spring, was also shown in B. indica. Conclusion B. indica were mainly fed on fiber food, as well as starch and animal food, under natural conditions. Diversity of food structure was associated with the reproduction and population growth, growth season of crops and vegetation types of the habitat.

【Abstract】 Objective To study the synergistic mechanism of synergistic rodenticides, and to observe the pathological changes in rodents tissue so as to provide the evidence for its application. Methods The effect of synergistic rodenticides to CT, PT, APTT and FIB were evaluated at the condition of SD rat as a model. The pathological changes in the tissues were detected by paraffin slice and HE staining technique. Results Single synergist could prolong CT and APTT and also increased FIB. While both warfarin and synergistic warfairn could obviously prolong CT, PT and APTT and reduced FIB. Compared to warfarin, the synergistic warfairn could increase CT, PT and APTT and reduced FIB. The histology and pathology observation indicated that synergistic warfairn could lead to a peptic ulcer compared with warfarin. It also led a pneumorrhagia and necrotic liver in toxic rats. Conclusion It suggests that synergist has an anticoagulant function, and the anticoagulant role of synergistic warfairn is powerful than that of traditional warfarin. Synergistic warfairn also leads to internal hemorrhaget and other physiological disfunction, while single synergist does not cause the histopathological damage.

【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.

Objective To study the control effect of different concentration of chlormadinone acetate on popalation expansion of mice,and the active duration and optimum concentration of chlormadinone acetate against mice.Methods Different concentrations of chlormadinone acetate were fed to mice in different time,and the quantity growth dynamics of mice was observed.Results The reproduction of female mice was controlled by 10 mg/kg chlormadinone acetate in the first month,and pregnancy of female mice was only 30% to 40% in the second and the third month.Quantity of mice decreased 70% to 80% after five to six months.Mice behaved as preference and the feeding index exceeded 1.0.Conclusion Chlormadinone acetate is of significance reproductive to block reprodnction of mice.The effective time lasts 3 months for taking 10 mg/kg chlormadinone acetate once.

Objective To present a method for forecasting popalation dynamics of Rattus rattoides in the Pearl River Delta. Methods Model of multiple seasonal,model of addition seasonal and ARIMA model were used to simulate the temporal variation dynamics of Rattus rattoides population and the corresponding model were established for the middle-term and long-term prediction. Results Model of multiple seasonal,model of addition seasonal and ARIMA model were satisfying to simulate the accumulation and disappearance tendency of Rattus rattoides population. Based on the models,the average errors of forecasting Rattus rattoides population were ( 6.43± 1.87 ),( 10.34± 2.56 ) and ( 11.48± 2.78 ),respectively,and the accuracy rate of the emergence grade forecast were 91.67 ,83.33 and 66.67 ,respectively. Conclusion Model of multiple seasonal and model of addition seasonal could be used to forecast the emergence dynamics of Rattus rattoides population with the predicted model of X( t)=5.158 393 29-0.015 772 24 t)γ _T+t and X( t)= 5.181 308 46-0.008 617 24 t+ d _T+t.

Objective The distribution of farmland rodents were studied to provide theory foundation for rodent control in Guangdong province.Methods The rodent density of different environment was investigated using night trapping method.Results The density of farmland rodents was topmost in the intercrop region and the composing of rodents was different in various environment.In the regions that rice interplanted fruit tree or vegetable there was remarkable correlation between the distribution of rodents and rice growth stage.Rodent density in rice field was higher than in fruit or vegetable field in the second half period of rice growth,but it was the lowest after rice harvest.In a big sample site,due to the differences of crops,the development stage of the same crop and weeds condition,the rodent density varied from 1 to 4 folds with each other in usual,but the highest could reach 27.3 folds compared with the lowest.Conclusion The distribution of rodent was imbalance.On the circumstance that provided better foods and habitat,the rodent density was high.It was an effective method to control farmland rodents economically using rodenticide accurately known rat's primary habitat.

Objective To study the scientific measures for rodent control.Methods To compare the effects of rodent control by ecological measures or by rodenticide in the rat's habitat.Results The control effects were 34% to 96% in ecological experiment area used the methods of building sclerous penstock,planting short weeds on riverbank,recomposing pound,digging ridge of field and weeding.In the area applying rodenticide only on rat's habitat,the effects of rodent control were high and retrench man-hour.Conclusion Applying rodent control on the rat's habitat is important measure to sustainable rodent control.

Objective To study the action of chemical control on rodent community structure for rodent forecast and control.Methods The anticoagulate rodenticides were used to control farmland rodents in spring and summer every year,the species,density and biomass of farmland rodents in Guangdong province were investigated with night trapping method from 1987 to 2000.Results After use of anticoagulate rodenticides for a long time,the percentage and biomass of Bandicota indica increased distinctly and those of Rattus rattoides reduced,and brought about changes to the rodent community structure and the index of diversity of farmland rodent community.Conclusion Chemical control resulted in the increase to the density of those rodents with larger size and stronger endurance to the rodenticide.