ISSN 1003-8280 CN 10-1522/R 中国疾病预防控制中心 主办
Objective To observe the assessment for deratization effect used with rat footprint plate method and S100 check method, and comparison the accuracy of two methods. Methods On-the-spot test was carried out at the Zhangheitun village of Linyi city, a total of 280 households. It was divided into two groups, each group of 140 households, the first group put 0.05% Diphacine-Na corn poison bait in cement poison bait box, the second group put 0.05% Diphacine-Na wheat poison bait in. Two methods of rat footprint plate method and S400 check were used to evaluate the deratization effect at the same time. Results At the first group, the assessment of deratization rate with rat footprint plate method at different periods of time were 54.05%, 54.78%, 73.19% and 92.47% respectively on the 10 d, 20 d, 30 d and 60 d, and the assessment of deratization rate with S100 check method at different periods of time were 79.40%, 88.38%, 95.64% and 98.87% respectively on the 10 d, 20 d, 30 d and 60 d, comparison two assessment methods, they have statistically significant(10 d, χ2=71.540; 20 d, χ2=176.230; 30 d, χ2=181.730; 60 d, χ2=56.270, P<0.01). At the second group, the assessment of deratization rate with rat footprint plate method at different periods of time were 35.51%, 51.02%, 71.28% and 85.54% respectively on the 10 d, 20 d, 30 d and 60 d, and the assessment of deratization rate with S100 check method at different periods of time were 74.08%, 87.32%, 95.13% and 97.53% respectively on the 10 d, 20 d, 30 d and 60 d, comparison two assessment methods, they were statistically significant (10 d, χ2=145.720; 20 d, χ2=231.720; 30 d, χ2=214.560; 60 d, χ2=104.230, P<0.01). Conclusion The S100 check method is more suitable for the assessment of deratization effect, since its quality and accuracy. And the rat footprint plate method better suited to determine the population density of rats, and identifying the rat density situation, it was convenient and practical.
Objective To observe the killing effects of 0.05% diphacinone sodium in the form of wax-coated poison bait corn granules, wax-coated poison bait wheat granules, or wax-coated poison bait mixed granules on Rattus norvegicus and Mus musculus in rooms. Methods A total of 760 rooms (around 15 m2 every room) were selected from the area with centralized residence in Zhangma Village, Jinan, China; wax-coated poison bait mixed granules were placed in 249 rooms, wax-coated poison bait corn granules were placed in 267 rooms, and wax-coated poison bait wheat granules were placed in 244 rooms. In each room, 3 piles of wax-coated poison bait (10 g/pile) were placed for 4 d, and observation was performed for 26 d. The killing effect of wax-coated poison bait was evaluated by grid/plate method (S400). Results The killing rates of wax-coated poison bait mixed granules and wax-coated poison bait corn granules were 97.45% vs. 92.44% (u=5.22, P<0.01) for R. norvegicus and were 100% vs. 99.47% (u=1.46, P>0.05) for M. musculus. The killing rates of wax-coated poison bait mixed granules and wax-coated poison bait wheat granules were 97.45% vs. 96.59% (u=1.19, P>0.05) for R. norvegicus and were both 100% for M. musculus. Conclusion Wax-coated poison bait has good killing effects on R. norvegicus and M. musculus. Wax-coated poison bait mixed granules, which are composed of wax-coated poison bait corn granules and wax-coated poison bait wheat granules at a ratio of 7:3, have a better killing effect on R. norvegicus than wax-coated poison bait corn granules.
Objective To observe the role of ecological approaches to deratization in keeping the rat density in large hotels as low as possible, providing a scientific basis for future deratization. Methods First, 0.005% bromadiolone corn poison bait was laid out for 6 consecutive days in the four large hotels with similar environmental conditions and serious rodent damage. And then the 4 hotels were randomly divided into two groups, of which ecological approaches to deratization were followed in one, with the other used as the control group. S-100 method was used to evaluate the deratization effect by the deratization rate based on the difference in the rodent density between the 2 groups within 6 months. Results The deratization rate of 0.005% bromadiolone corn poison bait for the 4 hotels was 96.92%, 97.06%, 96.82% and 97.53%, respectively, with the overall deratization rate being 97.12% within the 6 months. By the end of the observation, the rat density of the 2 hotels in the test group increased only by 2.97 compared with that at the time when corn poison bait deratization was completed, while the density of the 2 hotels in the control group increased by 34.34 in the same period of time with a difference of 31.37 between the two groups(u=22.24, P<0.01). Conclusion The deratization effect with poison bait followed by ecological approaches is a highly effective means for safe deratization and prolonged maintenance of the state.
Objective To investigate the susceptibility and resistance of larvae and adult of Culex tritaeniorhynchus in Licheng district, Shandong province to the commonly used insecticides, providing the basis for chemical control of the insects. Methods A large number of adult Cx. tritaeniorhynchus were collected outdoors in the peak seasons. The first filial generation of larvae was obtained by feeding the collected adults with blood from mice. The larvae obtained and the adult female mosquitoes, which had been captured in the field and had laid the first eggs in the lab, were used as test insects. The susceptibility of the adult and larvae to commonly used insecticides were determined with the drug membrane contact method and the impregnation method respectively, as the WHO protocol, with the knockdown rate and mortality of the adult mosquitoes and the LC50 (95%CI) for the larvae calculated and their resistance levels to commonly used insecticides compared. Results The mortality of the adult exposed to 0.05% deltamethrin (contact for 1 h), 0.05% beta-cypermethrin (1 h), 0.25% permethrin (3 h), 0.45% permethrin (3 h), 0.05% cypermethrin (1 h), 0.45% tetramethrin (1 h), 1% fenitrothion (2 h), 0.1% propoxur (2 h) and 4%DDT (4 h) beyond 24 h were 85.0%, 74.6%, 38.0%, 92.9%, 36.2%, 43.6%, 16.1%, 16.9% and 36.4%, respectively. The LC50 and the corresponding 95%CI of deltamethrin, beta-cypermethrin, and permethrin for Cx. tritaeniorhynchus larvae were 0.0046 (0.0037-0.0055), 0.0113 (0.0092-0.0136), 0.0325 (0.0289-0.0369) mg/L, respectively; the LC50 (95%CI) of dichlorvos, temephos, fenitrothion and malathion and BPMC were 4.9047 (3.8612-6.4215), 9.5733 (7.4644-12.5296), 1.2694 (1.0280-1.5055), 0.7750 (0.6060-0.9842) and 4.4237 (3.7406-5.2769) mg/L, respectively. Compared to the susceptible strains reported in previous literature, the resistance coefficients of the larvae of Cx. tritaeniorhynchus were 11.5, 1.9 and 8.8 to deltamethrin, beta-cypermethrin and permethrin, respectively, and 76.6, 7977.8, 256.4 and 84.2 to dichlorvos, temephos, fenitrothion and malathion, respectively. Conclusion Adult Cx. tritaeniorhynchus in Licheng district has developed resistance to the commonly used insecticides, with a very high resistance seen to organophosphate and carbamate pesticides in the adult. The resistance of larvae to temephos is highest among the organophosphates.
Objective To observe the deratization effects of acute and chronic bait poisons applied in bait boxes on rodent, particularly Mus musculus and Rattus norvegicus. Methods On-the-spot test was carried out in West Caishi Village, Licheng district, Jinan city. One bait box, containing 0.5% gophacide and 0.05% sodium diphacinone wheat granules of 50 g in the acute poisoning group or 100 g in the chronic group, was placed in each room. Each group included 90 households for effect assessment using the S100 grill powder-track method. Results For the acute poisoning group, at day 5, 10, 15 and 20, the overall deratization rates were 77.54%, 82.36%, 88.50% and 93.78%, respectively; the killing rates on M. musculus were 76.81%, 82.83%, 88.92% and 94.14%, respectively, and on R. norvegicus 100%, 68.29%, 75.61% and 80.49%, respectively. As to the chronic bait group, at day 10, 20, 30 and 60, the overall deratization rates were 90.93%, 93.17%, 98.11% and 98.28% respectively; the killing rates on M. musculus were 91.12%, 93.24%, 98.18% and 98.24%, respectively and on R. norvegicus 80.95%, 92.86%, 95.24% and 100%. The overall deratization effect at day 10 in the chronic group was better than that of the acute group (u=11.43, P<0.01). Conclusion Chronic anticoagulant baits applied in bait boxes were significantly effective in rodent control.
【Abstract】 Objective To compare the characteristics of mosquito communities structure at different altitude of Mengshan mountains Methods The mosquito communities structure at different altitude of Mengshan mountains were compared and analyzed with the indexes of substance content of biota(SCB), species abundance and diversity(SAD), probability of interspecific encounter(PIE), community uniformiry(CU), biomass (BM) and species density(SD), and the relativity of mosquito communities comparability index was performed. Results A total of 2013 mosquitoes were colleted. Of which, a sum of 1724 mosquitoes were collected within 200-300 m, accounting for 85%. There were 257 mosquitoes at 700-800 m, accounting for 13%, and only 32 mosquitoes at 1156 m which was the top of the mountain, accounting for 2%. The six index mentioned above were 13, 0.345, 0.272, 0.310, 1.20, and 1724 at 200-300 m, 12, 0.417, 0.443, 0.417, 0.18, and 257 at 700-800 m, and 9, 0.677, 0.845, 0.750, 0.06 and 32 at 1156 m. The comparability index between 700-800 m and 1156 m was higher with the value of 0.3625, following with the indexes between 700-800 m and 200-300 m which the values were all 0.1852. And it was the lowest between 1156 m and 200-300 m with the value of 0.1452. The results showed that the distance was nearer, the comparability was bigger, according with the practical investigation results. Conclusion There was distinct difference among the mosquitoes communities diversity at the different altitude. The SCB, BM and SD of mosquito communities in higher altitude were lower than those in lower altitude. But the CU, SAD and PIE of mosquito communities in higher altitude were higher than those in lower altitude. Furthermore, the distance of habitats was nearer, the community structures were more similar, and vice versa. The biological diversity was of great importance to study community structure of mosquitoes.